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Publication numberUS2219310 A
Publication typeGrant
Publication dateOct 29, 1940
Filing dateOct 20, 1927
Priority dateOct 20, 1927
Publication numberUS 2219310 A, US 2219310A, US-A-2219310, US2219310 A, US2219310A
InventorsHaugh Jr Henry A
Original AssigneeEngineering & Res Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Self-regulating automatic traffic control system
US 2219310 A
Images(4)
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Description  (OCR text may contain errors)

Oct. 29, 1940. H. A. HAUGH. JR Z ,3

SELF-REGULATING AUTOMATIC TRAFFIC cou'mon srs'rsm Filed Oct. 20, 1927 4 Sh eets-Sheat 1,

A Street Fig. 1

B Street Y I /n vefi or.- HenryAHaug/yJn ttorney.

2 1949- H. A. HAUGH. JR 22 9.

SELF-REGULATING AUTOMATIC TRAFFIC GQN' KROL SYSTEM Filed 001;, 20, 19.217 4 Sheets-Sheet 2 Inventor.

' fl- Henry A.Haugh.J/:

I %orney.

I To Fire Headquarters 0d. 29, 1940. HAUGH, JR 2,219,310

SELF-REGULATING AUTOMATIC TRAFFIC CQNTRQLI SYSTEM 4 Sheets-Sheet 5 WRNNRQbQQYMt Mkt 0k Filed Oct. 20, 1927 Oct. 29, 1940. H. A. HAUGH. JR 2,219,310

SELFREC-ULATING AUTOMATIC TRKFFIC GONTROL SYSTBM 'Filed Oct. 20, 192 7 4 Sheets-Shet 4 in mm tor:

' Henry/4. Hau hJr:

Ai iom ey Patented Oct. 29, 1940 UNITED STATES I SELF-REGULATING AUTOMATIC TRAFFIC CONTROL SYSTEM Henry A. Haugh, Jr.,

by mesne assignments, Research Corporation,

New Haven, Conn, assignor,

to The Engineering and East Norwalk, Conn, a

corporation of Delaware I Application October 20, 1927, Serial No. 227,490

39 Claims.

This invention relates to automatic self-regulating traflic control systems and more particularly to a system for controlling vehicular trailic at highway intersections. A traflic control sys- 5 tem embodying my invention is not limited in its use to the regulation of highway traflic but may be employed with equal facility at any intersecting 'trafflc lanes wherein it is desired to automatically regulate the passage of trafllc through the intersection by the presence of vehicles desiring to use the intersection. Such a system may be employed at railway crossings where it is desired to operate any convenient warning signal. v One fault of the ordinary stop and go installation employing signals for street traflic control, and regulated by a timing device which exhibits the signals in a periodic sequence without regard to traffic conditions, is that it frequently happens that the stop signal is turned against moving vehicles, in order to give the right of way to the trafllc on the intersecting street when there are no waiting vehicles thereon. Another fault with such ordinary timed systems is that the right of way is retained on a street longer ,0 than required, causing vehicles on the .other street to wait needlessly. These conditions needlessly delay traffic, and cause congestion at intersections. The primary object of my invention is to provide a self -regulating traflic control system which shall be mechanically dependent upon actual .volume and distribution'of traflic. This object is accomplished by providing a mechanical system of traffic control which shall function in response to the particularcondition of traflic' flow, and operate the desired signal in response to the actual volume and distribution of traflic rather than upon any arbitrary time setting.

A further object of my invention is to provide a system of traflic control wherein an indicating signal is operated by the trafllc through a timing mechanism, by the timing mechanism itself, or by both, in such a way:

1. That right of way is given successively to sev- 7 eraltraflic lanes in an order which maybe pre-- determined but in such a way that the length of time which one lane retains the right of way is dependent upon either the approach of vehicles in said lane, upon the approach of vehicles in one or more other lanes, or upon both.

2. That a traflic lane which does not require the right of waycannot hold it to the disadvantage of one which does.

3. That a vehicle whose progress is prevented by acontinuous stream of opposing tramc may I means right not be required to wait more than a fixed period of time, but that within this period is given right of way for as long as required for itself and fol- I lowing vehicles up to the aforementioned time 5 limit.

4. That interfering lanes of trafllc shall not be permitted to hold the right of way simultaneously.

5. That a vehicle which has passed the actuating means is protected against opposing traflic for a period of time suflicient to permit the said vehicle to pass the intersection of the trafllc lanes. I

6. That a vehicle which approaches an intersection on any lane of trafllc is given immediate right of way on condition and only on condition that there be no opposing traffic in or immediately approaching the intersection.

7. That when a vehicle is not given immediate right of way or has right of way taken from it before it has had sufficient time to reach the intersection, the system will be left in such a condition that right of way will return to the delayed car at the earliest possible moment.

8. That continuous vehicular'trafllc in one lane is periodically interrupted to allow pedestrians to cross this lane even in the absence of vehicular traflic in the lane of the pedestrians.

9. That when the signal means and timing system is disconnected from the trafllc actuated of way is given successively to the various traffic lanes according to a predetermined sequence and each for a predetermined time interval,

10. That by simple adjustments in the system, all fixed time intervals and responses to traflic in various lanes may be adjusted to meet various distributions and densities of traflic.

Other objects will be more manifest by reference to the following specification and drawings and specifically set forth in the claims.

In the drawings:

Fig. l is a diagrammatic view showing a highway intersection employing a signal system em bodying my invention.

Fig.2 is a diagrammatic view showing the circuits of an apparatus for operating the signal at intersecting traflic lanes.

Fig. 2a is an across the line arrangement Fig. 2.

Fig. 3 is a detail view showing a section of a vehicle actuated contact device.

Fig. 4 is a wiring diagram for two cont-act devices in a traffic lane, and located at opposite sides .of the intersection.

and red, yellow,

' side of the street a flow of gas or liquid A self-regulating automatic tramc control system embodying my invention comprises three parts, a vehicle indicator placed in or at the side of the road, an electrical time limiting control system, and a signal device to indicate right of way to tramc. The function of the indicating device is such that a vehicle approaching the intersection of two or more traffic lanes actuates an electrical control circuit. The function of the electrical time limiting control system is to receive actuation produced by the vehicle and to pass this actuation on either instantly or after the passage of some timed period to the signal means which shall then warn the vehicle either to stop or shall give it the right of way. The nal means to inform the trafiic in each street when to go and when to stop my be and green lights now in general use, and these are mentioned in this description, but other means such as semaphore arms, horns, or bells or any other signal means may be used with equal facility. The vehicle actuated means may be of several types as hereinafter mentioned:

One means actuated by the approaching vehicle may be of a mechanical nature such as a mechanical switch located in the street or at the and electrical contact being made upon passage of the vehicle.

Another means for detecting and recording the presence of an approaching vehicle may be any beam of light projected across the highway and received upon a photo-electric or light sensitive electric cell so that an approaching vehicle causes an interruption or fluctuation in an current passing through photo-electric cell.

An electromagnetic device located in the street or at the side of the street may also be arranged in such a manner that an approaching vehicle shall actuate the device to interrupt an electric circuit.

The approaching vehicle may be caused to pass over a flexible tube placed across the highway, said tube containing a' gas or a liquid. The vehicle crossing this tube could either interrupt within the tubethereby causing a mechanical switch to actuate the electrical circuit, or it might operate the mechanical switch merely through the accompanying change electrical the light sensitive or of pressure in-a static gas or liquid in the flexible tube.

The time limit control circuit operates as follows: Assume that there are no vehicles approaching on the intersecting streets designated by A and B; a yellow signallight appears in both streets. A- vehicle approaching from A-street now operates the A-street actuating means and contact relays immediately close the circuit, thus lighting theA-street-green and the B-street-red lights and simultaneously extinguishing the yellow lights in both streets. A-street now has the right of way. The device provides for relinquishing the A-street green light under any one of 1. WhenA-street traffic has all passed the intersection.

2. If A-street tramc is still moving at the end of a predetermined period (such as 30 seconds) the green light is yielded to permit pedestrians to'cross A-street.

3; If A-street trailic is still moving at the end of the 30 second period and vehicles arewaiting on B-street, the A-street green light is yielded in favor of B street.

the standto A-street. If there is no either street the lights in both streets continue to show yellow until a vehicle approaches. Right These limitations on the period during which A-street may hold the green light, are controlled by suitable time limit relays hereinafter de scribed.

Provision to yield the A-street green light whenever the A-street trafilc has passed the intersection (case 1 above) is made through the use of a time limit relay set to open the A street-green and the B-street-red light circuit, after said relay has been continuously energized for a predetermined period, as for example, seconds. This relay is set back to its starting position at each time a vehicle operates the A- street actuating means. Hence if a small number of vehicles requiring the use of this interr set back to its starting position; thus preventing it from interrupting the A-street-green and the B-street red light circuit. Under these conditions another time limit relay set for a predetermined period, say a thirty second period, functions. vThe action of this relay is described in the next paragraph.

To provide for case 2 mentioned above, in which continuous traffic on A-street must be interrupted to permit pedestrians to cross A-street, another time limit relay set to open the A-street green and the B-street red light circuit is connected so that it will be energized when A-street is given the green light. back to its starting point by vehicles passing the A-street actuating means. Hence it yields the right'of way held by A-street seconds after said right of way was given, unless the ten second relay had previously functioned due to the cessation of A-street traffic.

The combined effect of these, time limit relays causes A-street to hold the green light for the full 30 second period only if trafllc on A-street requires it, yielding said light before the 30 second period expires if all the A-street traffic has passed the intersection.

The control circuit is A-street has yielded the green light under any of the above outlined conditions a yellow light is shown in both streets during a caution period. After the caution period waiting traffic determines which street is to get the right of way. If traflic waits on both streets, that on B-street is given the green light. If there is waiting traffic on A-street only, the green light reverts of way is then given immediately to the appreaching vehicle. In the next paragraph this is expressed in terms of. the functioning of the actual apparatus.

If at the end of this yellow caution period,

vehicles have operated the B-street actuating means since 10 seconds before said street last lost the right of way, the green light is given to B- street. If on-the other hand no vehicles have operated the B-street actuating means since 10 seconds before B-s'treet last lost the green light, and vehicles have operated the A-street actuating means since 10 seconds before A-street last lost so arranged that when This relay is not set traflic waiting on the green light, right of way returns to A-streeteffect of a wheel passing over a ramp in A-street after the yellow caution period. If the actuating means in neither street has been operated since 10 seconds before said street last lost the green light, the yellow lights will remain lighted on both streets until a vehicle approaches. Right of way is then immediately given to an approaching ve hicle on either. street.

A vehicle might approach the intersection from A-street during the last few seconds of A-streets 30 second period. The light might shift after said vehicle had crossed the actuating means but before it had crossed the intersection thereby stranding said vehicle between the actuating means and the crossing. To permit a vehicle so stranded to pass as soon as possible'the circuit is so arranged that the operation of the A-street actuating means during the 10 seconds directly preceding the yielding of the A-street green light (when yielded by the 30 second relay only) causes the green light to revert .to A-street at the first opportunit thereby releasing the stranded vehicle. For-this reason, the phrase in the preceding paragraph is worded since 10 seconds before said street last lost the green light.

In this description time limit relays operating to limit the period during which'A-street may hold the right of way were mentioned. Another set similar to that used to govern A-street would be provided to govern B-street when B-street should have the right of way. Their operation is just as that described in the case of the A-street relays.

There is included in the relay system a pair of time limit relays set to operate after they have been energized for a predetermined interval, for

example, 2 seconds. The function of these relays is to govern the length of the cautionary period between the red and green light period.

While I have described above a self-regulating automatic traflic control system embodying my invention, and have shown that this invention is-comprised of three main interconnected parts, I now describe in detail the construction of one complete and specific system embodying my invention. Referring to Fig. l of the drawings there is shown a complete self-regulating automatic traflic control system applied to intersecting streets Aand B. The vehicle actuated means are indicated by numbers 4, I, 0. and 1. The signalmeans in this particular embodiment is indicated at 9, and contains a red and a green electric lamp visible from either direction on A- street butnot visible on B-street; a red and a green electric lamp visible from either direction on B-street, but not visible from A-street: and a yellow electric 'lamp visible from both streets. Energy is supplied to these electric .lamps through the wires entering 9 as will be more completely described later.

The electrical time limiting control is ind cated by 8. Fig. 1. Wires l0. II and I 2' interconnect the A-street veh cle actuated means. while wires I0, II, and I2 also connect these two means to the electrical time limiting control. Wires I3, l4 and I5. interconnect the vehicle actuated means on B-street, while wires I3, I4, and I5 also connect these two means to the electrical time limiting control. Figure 3 shows a vehicle actuated means constructed according to this part cular embodiment, and numbers 90, 9|; 92, and 93 indicate electrical contacts, which are so arranged that when a vehicle passes over the ramp arm I04, this ramp and is pushed down, pivoting at I03, so that contacts 90 and 9| are separated and contacts Hand 93 are brought together. The

is to open the circuit between wires II and I2 by separating contacts 90 and 9|,and then make a circuit between wires l0 and II by contact between 92 and 93. When the wheel has passed, spring I03 causes arm I04 to rise separating contacts 92 and 93 thereby opening the circuit between wires l0 and II and re-establishes contact a I between 90 and 9| thereby re-establishing connection between wires H and I2 through contacts 94 and.95 on theother ramp on A-street. Fig. 4 indicates the way in which the two vehicle actuated means on any one street are interconnected in this embodiment of my invention. Contacts 06 and 91 parallel 92' and 93 and contacts 94 and 95 are in series with 90 and SI. Thus actuation of either ramp produces the same effect on the circuits. Fig. 2 or Fig. 2a, which disclose identical apparatus and circuits, show the construction and wire arrangement in-detail of an electrical time limiting control which is constructed according to this particular embodiment, and indicates also the electrical connections of the signal means, as well as a vehicle actuated means for each street. In Figs. 2 and 2a,, 89 (Y) is a yellow light visible from both streets, 83 (3G) is a green light visible'from B-street, 84 (AR) is a -red light visible from A-street, 85 (AG) is a green light visible from A-street, 86 (BR) is a red light visible from B street. Ramp arms I04 and I04 with their associated contacts represent vehicle actuated means on A-street and B-street respectively.

The control system includes the following relays: instantaneous operating contacts relays 26, 21, 34, 35 and .36; oil dash-pot relays 28 and 29 arranged to operate their armatures 30 seconds after their coils are energized; oil dash-pot relays 30 and 3| arranged to operate their armatures seconds after their coils'are energized; and oil dash-pot relays 32 and 33 arranged to operate their armatures 2 seconds after their coils are energized. All of the .oil dash pot relays release their armature immediately upon deenergization. The apparatus in the left half of Figs. 2 and 2a controls the display of the A-street green signal 85 and the B-street red signal 86. That in the right half controls the display of the .B-street green signal 83 and the A-street red signal 84. These two groups of apparatus are interconnected in such a way as to prevent the simultaneous display of the green signals on both streets but to permit the green signal on either street to be displayed in response to traflic or by cyclic operation as will be more fully explained later. Furthermore these groups cooperate to display-a yellow signal to both streets between changes in the green signal display as will be explained street.-Assume a vehicle approaches on A street and actuates ramp 5, depressing bar I04, thereby opening contacts and BI and closing contacts 92 and 23. The bar I04 may be any portion of a contact device and is shown as a lever pivoted about point I03 and held in position by a spring I83' (see Fig. 3). Contacts 82 and 83 having been engaged, relay 26 is energized through the circuit including wires I2l and H8, switch I81, wire I I, contacts 82 and 83, wire I8, switch I81, wire I38, the coil of relay 26 and wires III' and H6. In Fig. 2 wire III connects with wire II6 through wire III. Armatures 45 and 48 of relay 26 are now moved into their operated position.

The engagement of armature 45 with contact 46' completes a holding circuit supplying positive power to the coil of relay 26 so that this relay will remain energized after the vehicle has passed ramp 5 and permitted contacts 82 and 93 to separate again. This holding circuit includes wire I48, armature 45, contact 46, wires H2 and I5I., contact 6i, armature 58 and wires i 26 and I2I.

The engagement of armature 48 with contact 58 energizes relay 34 through a circuit including wires H6 and HI, armature 48 and contact 58, wires H1 and H8, armature 88 and contact 88 of relay 36, wire I11, switch I85, wire N8, the coil of relay 38, wire I28, switch I85, wire I48, contact 61, armature 65, and wires I6I and I2I. The armatures 1i and 11 of relay 34 now assume their operated positions.

The separation of armature II from contact 12 extinguishes the yellow signal 88 which had been energized through wires I2I and I42, armature II, contact 12, wire I43, signal 88, wire I46, contact 15, armature 14 of relay and wires I48 and H6.

The engagement of armature H with contact 13 energizes the A street green signal 85 and the 13 street red signal 86 through wires I2I and I42, armature 1I, contact 13, wire I44, signals 85 and 86 in parallel, wires 81 and I I6.

The engagement of armature 11 with contact 18 completes a second holding circuit supplying positive power to the coil of relay 26. This circuit includes wire I48, armature and contact 46 of relay 26, wires I I2 and I5I,.contact 18, armature 11 and wires I22 and I2I. The pu pose oi .this second holding circuit is to cause relay 26 to remain energized while relay 34 remains energized even though the first traced holding circuit for relay 26 may be opened by the separation of armature 58 from-contact 6| of relay 38 which will occur under circumstances to be explained later in these specifications.

The separation of armature 11 from contact 18 of relay 34 deenergizes relay 33 which had been energized through a circuit including wires I2I.

and I22, armature 11, contact 18, wire I21, the coil of relay,33, wire I58, armature 51 and contact 58 of relay 28, wire I58, contact 63 and armature 62 of relay 3| and wires I23 and H6.

Armature 68 of relay 33 now assumes its un operated position. The separation of armature 68 from contact 18 assures that relay 35 will remain deenerglzed, with the B street green signal consequently also deenerglzed, until relay 33 again operates which can occur only after the A street green signal has been extinguished and I a period of yellow caution signal display has followed.

The engagement of armature 68 with contact 68 energizes timing relays 28 and 38. The circuit through which relay 28 is energized includes wire I2I, switch point 24 and switch I8, wire I32, the coil of relay 28, wires I15 and I24, contact 68, armature 68 and wires .I68 and H6. The circuit through which relay 38 is energized includes wires H6 and I68, armature 68, contact 68, wires I24 and I16, the coil of relay 38, wire I38, switch I81, wire I2, contacts 88 and 8I associated with ramp arm 5 in A street, wire I I, switch I81 and wires H8 and I2I.

Relays 28 and 38 thereupon begin to time their periods. If no other vehicle approaches from A street and contacts 88 and 8I consequently remain in continuous engagement, relay 38 will be continuously energized. At the end of its time period, assumed here to be 10 seconds-relay 38 will operate to terminate the A street green signal display as follows. The separation of armature 58 from contact 68 opens the circuit energizing the coil of relay 32. This circuit included Wires I2I, and I26, armature 58, contact 68, wire 3,

contact 56, armature 55, wire I I4, the coil of relay 32, wire II5, contact 82, armature 88 and wires 38 and II 6.

Armature of relay 32 now separates from contact 61 and make contact with 66 thereby deenergizing relay 34 and through wire I 25 energizing relays 28 and 3i. The circuit for relay 28 includes wire II6, switch point 25 and switch I9, wire I55, the coil of relay 28, wires I14 and I25, contact 66 and armature 65 and wires IN and I2I. Positive power is supplied to the coil of relay 3I through the same circuit which feeds the left coil terminal of relay 28 since wire I25 connects with both wire I13 and wire I14. Relay 3| gets negative power through wire I88, switch I88, wire I3, contacts I33 and I34 associated with ramp arm I84, wire I4, switch I88'and wires I12 and H6. The deenergization of relay 34 causes armature H to break from lcontact 13 and make contact with 12, thereby extinguishing green light 85 and red light 86 and lighting the yellow light 88. When relay 34 is de-energized, armature 11 breaks from contact 18 and makes contact with 19. Breaking contact. 18 opens the holding circuit and releases the armature of relay 26, thus dropping it back to its normal unoperated position. The other holding circuit for relay 26, previously mentioned, is open due to the separation of armature 58 from contact 6 I of relay 38. Armature 11 making contact with 18 energizes relay 33 through a previously traced circuit. Two seconds after relay 33 is energized, armature 68 breaks from contact 68 thereby de-energizing relays 28 and 38 and makes contact 18. The deenergizing of relay 28 has no effect on the circuit inasmuch as it had not been energized continuously for 30 seconds. The release of relay 38 causes armature 58 to make contact with and H thereby energizing relay 32 from wire I 26 through its previously traced circuit, which, after 2 seconds, causes armature 65 to break from contact 66 thereby de-energizing relays 28 and 3| and make contact with 61. The de-energizing of relays 28 and 3| has no efiect on the circuit, inasmuch as neither had been energized long'enough to operate. A yellow light is now shown in both streets and the entire system has returned to its original condition.

Cass II.C0ntinu0us traflic on A-street with no traflicon B-street.If in the preceding operation no cars had approached the intersection from B street, but vehicles had approached on A street each actuating an A street ramp either (III 5 or 1 within 10 seconds of the previous actuashowing in B street, and in addition providing that current flow through the coil of relay 23, through armature 45 and contact 43 even after armature 11 shall have broken contact from 13. The purpose of thisis brought out later. The 30 second time-limit relay 23 which was energized through its previously traced circuit at the same time that 10 second relay 33 was energized, breaks the circuit between armature 55 and contact 53 30. seconds after it is energized, thereby releasing the 2-second time limit relay 32. Armature 35 breaks from contact 31 thereby interrupting the current operating relay 34. Armature 1I breaks contact from 13 and makes contact with 12 thereby extinguishing green fight 35 showing in A street and red light 33 showing in B street, and lighting the yellow light 33. Armature 11 breaks from contact 13 but in this particular case does not interrupt the current operating relay 23 because of the fact that said current is supplied through contacts 53 and 3I on relay 33 which are connected in parallel with contacts 11 and 13. The fact that relay 23 therefore remains energized causes lights 35 and 33 to show after yellow light 33 has been lighted for 4 seconds as is explained in detail in the subsequent discussion, thus returning the right of way to A street after giving pedestrians'a 4 second period in which to cross A street. The actual operation of the circuit to produce this eflect is as follows. Armature 11 connects with contact 13, thereby energizing the. 2 second time limit relay 33 as before described.- Two seconds after relay 33 is energized armature 33 breaks from contact 33 thereby opening the circuit to relays 23 and 33 through wire I24, whereupon armature 55 makes contact with '53, thereby energizing 2 second relay 32. Two seconds after relay 32 is energized, armature 35'makes con- "tact with 31, thereby energizing relay 34 whereupon armature 1I breaks from contact 12 thus extinguishing the yellow light and makes contact with 13 thus lighting the A street green light 35 and the B street red light 33. This cycle of operations repeats as long as vehicles operate either ramp in A street within intervals of 10 seconds and none operate a ramp in B street.

- In the event that vehicles iailto operate either and contact 43, wires I3I and I52, contact 34,.

A street ramp within an interval of 10 seconds, the subsequent operation is as described in Case I.

Cass IIL-One vehicle on A street followed within 10 seconds by one vehicle on B street.- Under this condition, the circuit operates as in Case I with the following changes. When relay 34 is de-energized through the breaking of arma ture 35 from contact 31, armature 11 makes contact with 13. A vehicle operates either ramp ,4 or 3 in B street which causes current to flow through the coil of relay 21. The contacts of ramps 4 and 3 control relay 21 just as contacts in ramps 3 and 1 control relay 23, and they controlrelay 3I just as contacts in ramps 5' and 1 control relay 33. The actuation of ramp 3 causes contacts I53 and I54 to engage thus energizing relay 21 through a circuit including wires I I3 and I12, switch I33, wire I4, contacts I53 and I34.

wire I5, switch I33, wire I53, the coil of relay 21 and wires I33 and I2I. In Fig. 2 wire I33 connects with wire I2I through wire I33. Re- .lay 21 is now held in the operated position by current flowing through wire I51, armature 41 armature 32 and wires I23 and H3. 11 making contact with 13 energizes relay 33 through contacts 51, u, u, and :2. Two soconds alter relay 33 is energized, armature 33 makes contact with 13 thereby operating relay 35 through wires II3 and I33, armature 33, contact 13, wire I53, switch I33, wire I33, the coil of relay 35, wire I32, switch I33, wire I23, contact IIII, armature I33, wires I23 and I31, contact 53, armature 52, and wires I33 and I2I. The separation of armature 33 from contact 33 deenergizes relays 23 and 33. Relay 33 which has been operated now assumes its unoperated condition. The operation of relay 35 causes armature 14 to break contact from 15 thus extinguishing the yellow light and to make contact with 13 thereby lighting the green light 33 on B street and red light 34 on A street. The circuit for theB street green and the A street red light includes wire 33, lamps 33 and 34 in parallel,

wire I41, contact 13, armature 14 and wires I43 and H3. Thus the eflect has been that the vehicle in A street has retained the right of way for 10 seconds and at the end or this 10 second period, the signal has gone through the cautionary yellow period of way on B street. 5

' When relay 35 was energized armature 33 broke the circuit with contact 32 and made contact ,with 3|. Breaking or the circuit between 33 and 32 causes relay 32 to remain ale-energized after armature 53 has made contact with 33 to an indication of right and 3|. When relay 32 was originally deenergized by the separation of armature 59 from contact 33, as explained in Case I, armature made contact with 33 thereby energizing time limit relays 23 and 3I the circuits for which have been traced previously. Ten seconds afterrelay 3I was' energized, due to the fact that neither ramp in 13 street had been operated by a second vehicle, which would have de-energized relay 3|, armature 32 breaks contact with 33 and 34 thereby de-energizing relay 33 thus permitting armature 33 to break contact from 13 and make contact with 33. The breaking of the circuit between 33 and 13 de-energized relay 35, thus breaking contact between 14 and 13 thereby extinguishing green light 33 and red light 34 and making contact between 14 and 15 thus lighting the yellow light 33. The separation of armature 33 from contact 3| deenergizes relay 21 which had been energized through a circuit including wires H3 and 33, armature 33, contact 3I, wires I52 and I3I, contact 43, armature 41, wire I51, the coil of relay 21 and wires I33 and I2I. In Fig. 2 wire I33 connects with wire I2I through wire I33. Armature 33 in making contact with 32 energizes the 2 second relay 32 through contacts 55, 53, 33- and 53 on'relays 23 and 33.- Two seconds after relay 32 is energized armature 33 makes contact 31 and breaks from contact 33 therebyde-energizing time limit relays 23 and 3I. In as much as relay 23 had not been energized for a suflicient length of time to I operate its armature, it has not acted to control the circuit. The de-energizing oi. relay 3| permits armature 32 to make contact with 33 and 34 thereby energizing relay 33, through armature 11 and contact- 13. Two seconds after Irelay 33 is energized, armature 33 breaks from 33 thereby de-energlzing relays 23 and 33' and makes contact with '13 so that relay -35 operates immediately when relay 21 is energized. -The circuit has now completed its cycle and has returned to the condition atthe beginning of Case I, and as shown in Fig. 2 and Fig. 2a.

Case IV.-Continuous trafl'ic on A street with one vehicle waiting on B street-Under these conditions, the circuit operates as outlined in Case II until a vehicle operates one of the ramps in B street. The opening of the circuit between contacts 55 and 58 which occurs 30 seconds after relay 28 is energized, de-energizes relay 32 causing armature 55 to break from contact and "make contact with 6. Connecting armature 55 with contact 66 energizes relays 29 and 3|. Breaking the circuit between armature 65 and contact 61 de-energizes relay 34 whereupon ar deenergize relay 26 because current for relay 28 is supplied through wire I25, armature 59 and contact 5|, wires l5! and H2, armature l5 and contact 45 and wire 0. In the meantime vehicle has operated one of the ramps on B street energizing relay 2'41. Current to keep relay 21 energized after said vehicle has crossed the ramp flows through armature H,- contact 48, contact 64, and armature 62. Armature 52 now makes contact with contact 53. Armature H which made contact with contact 18 when relay 34 was de-energized thereupon energized relay 33 through contacts 57, 58, 63, and 62. Two seconds after relay 33 is energized armature 88 breaks from contact 69 thereby de-energizing relays 28 and 3B. Armature 88, through making contact with contact 18, now energizes relay 35 through switch I06 and contacts NH, I08, 53,

and 52. v Armature 14 now breaks from contact 15, thus extinguishing the yellow light, and makes contact with 16, thereby lighting the B street green light and the A street red light 8i.

Armature 86 breaks from contact 82 and makes contact with 8| thereby causing relay 32 to remain de-energized despite the closing of contact 55with contact 56. Armature 65 therefore remains in contact with 66 keeping relay 29 energized and also relay 3| energized, inasmuch as this case assumes that a second car does not pass over a B street ramp. Hence 10- seconds after relay 3! was energized armature 52 breaks from contact 63 and contact 84 thereby de-energizing relay 33. Armature 88, of relay 33, now breaks from contact 10 and makes contact with 59 thereby energizing relays 28 and 30. Relay '35 is now de-energized through the break between armature 88 and contact 10. Armature I4 now breaks from contact thereby extinguishing the B street green light 83 and the A street red light 84. The yellow light 89 is now lighted through armature l4 and contact 15. Armature at the same time breaks from contact 8| thereby de-energizing relay 21 inasmuch as armature 62 is not now in contact with 84. Armature 80 makes contact with contact 82 thereby energizing relay 32 through contacts 55, 58; 59, and 80. Two seconds after relay 32 is energized, armature 55 breaks from contact 58, thereby de-energizing relay 29 and relay 3 I ,and makes contact with 51, thereby energizing relay 34 through switch I05, contacts 88, 88, wires H8 and I I1, contacts 50 and 49. Armature 'H now breaks from contact 12 extinguishing the yellow light and makes-contact'with I3 again lighting the A street green light 85 and the B street red light 33. Armature TI also breaks from contact 18 thereby insuring that relay 33 remain de-energized even though armature Blbe in contact with 58 and armature 52 be in contact with 53 Armature Tl now makes-contact with 18 thus paralleling armature and contact 6|. The system has now returned to the condition in which it was when the single vehicle actuated the ramp in B street. In this description we have shown how continuous traflic in A street would be interrupted for a suflicient period to allow a single vehicle from B street to use the intersection, and how right of way would return immediately thereafter to A street in which the continuous stream of traflic had been interrupted.

Cass V.Continuous traific in both streets.- Under these conditions the circuit operates as it did in Case IV to transfer the right of way from A street to B street. But, continuous traflic in B street opens the contacts in the B street ramps through which the currentenergizing relay 3!- passes. Armature 52 therefore continues to make contact with 53 and 6 .1. Relay 38 therefore remains energized until armature 5i breaks from contact 58 which will take place seconds after relay 29 is energized. The energizing of relay 28 is caused in accordance with the description given in Case I. Armature 51 now breaking contact with 58 tie-energizes relay 33. Armature 68 breaks contact from 10 and makes contact with 69 thereby de-energizing relay and energizing time limit relays 28 and 30. Armature now breaks contact with 16, thereby extinguishing B street green light 83 and A street red light contact 8| which action has no effect on the circult inasmuch as this connection is also made by armature 82 and contact 64. Armature 38 makes contact with.82 thereby energizing relay 32. Two seconds after relay 32 is energized, armature 65 breaks from contact 66 thereby causing the de-energizing or relays 29 and 3i, thereby causing armature 5'Ijto make contact with 58. Armature 65 makes contactwith 5?! thereby energizing relay 38 through switch I55, contacts 99,. 98, 50 and 48. Armature II now breaks from contact 12 extinguishing the yellow light and makes contact with 13 lighting the A street green light 85 and the B street red light 88. Armature "breaks from contact 19 thereby causing relay 33 to remain de-energized even though armature 57 makes contact with 58 and armature 52 makes contact with 63. Armature 11 now makes contact with 18 and the circuit has returned to the condition in which it was at the beginning of this description.

Comnzorxon H.The operations described above under the headings Cases I, II, III. IV, and V, occur when the various switches are in the positions shown in Fig. 2 and Fig. 2a of the drawings. It may be seen from an inspection of Fig. 2 or Fig. 2a that if switch I is closed,

relay 25 is continuously energized through wires |2l and H0, switch. l8, wire I39, the coil 01' relay 26, and wires Ill and Hi. In Fig. 2 wire Ill connects with wire 6 through wire Ill thereby causing the right of way to return to Y ii the switches are as shown except that switch I1 is closed, the operation is as described in the last paragraph, except that the conditions described for A street and B street are interchanged.

CONNECTION IV.It can be seen that with both switches I8 and I1 closed, the right of way is granted alternately to each street and is held by each street.for any period between 10 and 30 seconds. If no vehicles actuate the ramp in a given street during a period of 10 seconds the 10 second relay functions to yield the right of way. If, on the' other hand, when said street is given the right of way, vehicles operate either ramp in said street at intervals seconds, the 10 second relay is repeatedly set back to its de-energized condition in which case the 30 second relay functions to yield the right of way 30 seconds after it is granted.

CONNECTION V.- It can be seen by an inspection of Fig. 2 or Fig. 2a of the drawings that if all the switches are as shown except that switch 2| makes contact with 38, then the opening of contacts 59 and 80 does not de-energize relay 32 unless relay 21 has been energized by a car operating either ramp on B street. As long as relay 21 is deenergized relay 32 is connected to positive power through wire Ill, armature 55, contact 56, wire H3, switch 2|, switch point 38, wire I35, contact 54, armature 52, and wires I30 and HI. Hence the 10 second relay 30 does not operate to cause the circuit to take'the right of way from A street unless a vehicle has operated one of the ramps on B street, since 10 seconds before B street last'lost right of way. With this connection the yellow signal is displayed to both streets in the absence of traffic. Any B street actuation will cause right of way to be granted thereto for 10 seconds which period is extendable up to thirty second by subsequent B street actuations occurring at intervals of less than 10 seconds. An A street'actuation will cause right of way to be granted thereto for a period of thirty seconds in the absence of any B street actuation. At any time after the first 10 seconds of this A street right of way period a B street actuation will immediately cause the yellow signal to be displayed after which right of way will be granted to B street except that A street actuations occurring at intervals ofless than ten seconds can maintain the A street right i of way up to a 30 second limit.

CONNECTION VI.-It can also be seen that with all switches as shown in Fig. 2 or Fig. 2a of the drawings, except that switch 28 makes contact with 31, the operation is as described above except' that conditions on A street and B street are interchanged. a

CONNECTION VII.--It can also be seen from an inspection of Fig. 2 or Fig. 2a of the drawings that with all switches as shown except that switch I8 is moved from contact with 24 to 22, relay 28 is energized only when relay 21 shall have been Operated by a vehicle actuating one of the ramps in 13 street. Therefore in the event of continuous trafllc on A street in which the A street ramps are operated at intervals of less than 10 seconds, A street continuously holds the right 01. way unless a vehicle on B street has actuated a ramp On that street since 10 seconds before B street last lost right, of way, energizing relay 2! which energizes relay 28 through contacts 52 and 53. Thirty seconds after relay 28 is energized, it iunctions to take the right of way from A street. The cessation of A street traflic will of less than 10. whether or not an A street cause the right of way to be transferable to B street by action of relay 30 before the 30 second period or relay 28 has expired.

CONNECTION VIH.-If the switches are as shown in Fig. 2 or Fig. 2a- 015 the drawings, except that switch I9 is moved from contact with 25 to 23 the conditions areas described in the above paragraph except that the conditions on A street and B street are interchanged.

CONNECTION IX.--If the switches are as shown in Fig. 2 or Fig. 2a of the drawings except that switch 18 makes contact with 22 and switch 2| makes contact with 38, right of way remains with A street, once it is granted, continuously ramp is actuated until a vehicle on B street has operated a ramp on B street since 10 seconds before B street last lost right of way. I l

The operation of relay 21 de-energizes relay 32 by opening contacts 52 and 54 providing the 10 second relay 3!) has already operated to open contacts 59 and 60. In the event that a vehicle has operated the A street ramp within an in terval of 10 seconds, armature 59 will be in contact with 60 thereby supplying current to relay 32, despite the opening. of contacts 52 and 54. Upon the expiration of the 10 second period following the operation of either A street ramp, armature 59 breaks from contact therebydr energizing relay 32, relay 21 being energizeil which immediately causes the right of way to be taken from A street. If, on the other hand, vehicles on A street operate thezA street ramps at intervals of lessthan 10 seconds, thus causing armature 59 to remain in contact with 88, relay 28 operates to open contacts and 58 therebyde-energizing .relay 32 thirty after the energizing of relay 21 by a B -street ramp actuated by a vehicle.

be seen vfrom Fig. 2- or Fig. 2a. 9f the drawings that if the. sw itches CONNECTION X.-It may are as shown, except that l9 makes contact with seconds 23, and 28 makes contact with 31, the operation is as described in the above paragraph except that conditions in A street and B street are interchanged.

CONNECTION XI.-It.can be seen from Fig. 2

or Fig.2a of the drawings that if the switches are as shown except that switch I8 is closed and switch 18 makes contact with 22, and switch 2| makes contact with 38, right of way reverts to A street, after each yellow period suqaeeding a period during which B street held th .rlght of way. A street then holds said right 0 way un-- til the end of the minimum period of 'lo'seconds of relay 39 after which right of way is instantly yielded in response to B street. actuations if no A street actuation has occurred during the preceding 10 seconds, or right of way is yielded by the operation of relay 28, thirty seconds after relay 28 is energized, if continuous trafflc on A street prevents the ing the said right of way. Relay 28 is' energized through contacts 52 made when'relay 21 is energized.

CONNECTION XlL-It may be seen from inspec-r tion of Fig. 2 or Fig. 2a of the drawings that if all switches are as shown except that switch I1 is closed, switch 19 makes contact with 23, and switch 20 makes contact with 31, the conditions are as outlined in the above paragraph except that the conditions indicated for A street and B street are interchanged.

CONNac-rroN XIII-It may be seen fom'inspection of Fig. 2 or Fig. 2a oi the drawings that 10 second relay from yield-' with the switches as shown except that switch 16 is closed and switch 2! makes contact with 38 these conditions if no vehicles operate either of the B street ramps during an-extended period, right of way is held by Astreet continuously except that every 30 seconds a yellow period of 4 seconds is introduced during which time the A street green and the B street red lights are extinguished. Immediately following this period,

right of way returns to A street. This yellow period is inserted to permit pedestrians to cross A street. With the switches as described in this case, if a vehicle operates a B street ramp, thereby energizing relay 21, right of way is given to B street immediately after an intervening yellow 'period providing no vehicle has operated either of the A street ramps during the preceding seconds and provided that the A street minimum period of 10 seconds has expired. If, on the other hand, a vehicle has. operated either of the A street ramps during the 10 second period immediately preceding the operation of the B street ramps, relay 32 is energized through contacts 59 and '60 despite the fact that the circuit is open between contact 52 and 54. Armature 59 is in' contact with 60 because under the above conditions relay 30'has not been energized continuously for 10 seconds. In the event that vehicles operate the A street ramps at intervals of less than 10 seconds relay 28 functions 30 seconds after right of way is given to A street to yield said right of way by de-energizing relay 32 through breaking the circuit between 55 and 5B. In this part of. the discussion, I have not traced the action beyond relay 32, since the operation subsequent to the de-energizing of relay 32 is always the same up to the point at which relay 34 turns off the A street green and the B street red and turns on the yellow light, these being accomplished respectively by breaking of armature H from contact 13 and making of contact between H and 72. This action takes place upon the de-energizing of relay 34 which is accomplished through armature 65 breaking from contact 61 when relay 32 is de-energized.

CONNECTION XIV.-It may be seen by reference to Fig. 2 or Fig.2a of the drawings that if the switches are in the position shown except that switch I"! is closed and switch makes contact with 37, the operation is as described in the preceding paragraph, except that the conditions on A street and B street are interchanged. CONNECTION XV."I'he circuit is so arranged that if it is desired to disconnect the traflic actuated means for any reason, this can be accomplished by throwing switch I01- so that it makes contact with 4!, 42, and 42', breaking contact from III, II, and I2, and throwing switch I08 so that it makes contact with 43, 43', and 44 breaking contact with l3, I4, and I5. Under these conditions relays and 21 are continuously energized through 4| and 42, 43 and. 44, and the coils of relays and 3! are disconnected from contacts l2 and I 3 respectively, thereby causing said relays to be continuously de energized. An

inspection of Fig. 2 of the drawings shows that independent of the position of switches of i5, ll, I8, 19, 20, and 2|, the system operates to give right of way alternately to. each street for 30 peats.

seconds, introducing a 2 second yellow period at each transfer. In this case, the action is as follows: Assume that the relays are as shown in Fig. 2 and Fig. 2a and that switch I01 is thrown to this new position before I08 is thrown to its new position. Hence relay 26 being the first to be energized, gives right of way to A street in the following manner: Armature 48 breaks from 5! and makes contact with 50'thus connecting to the power supply one terminal of the coil of relay 34 through wire H8 armature 88, contact 99, and switch I05. The other coil terminaI of relay 34 is connected to the other side of the power supply through armature 65 and contact 61 of relay 32. Relay 34 now being energized, armature ll now breaks from contact 12 thereby extinguishing the yellow light and makes contact with 13 thereby lighting the A street green light 85 and the B street red light 85. Armature I1 breaks from contact 19, thereby causing relay 33 to be de-energized. Armature 68 breaks from contact I0, thereby preventing any current from energizing relay 35, and makes contact with 69 thereby energizing the coil 0! relay 28. Thirty seconds after the coil of relay 28' is energized, armature breaks from contact 56, thereby de-energizing relay 32, whereupon armature breaks from contact 61 and makes contact with 66 thereby de-energizing relay 34 and energizing relay 29. When relay 34 is deenergized, armature H breaks from contact 13, thereby extinguishing the A street green light and the B street red light, and makes contact with 12, thereby lighting the yellow light. Armature 11 makes contact with 19, thereby energizing relay 33. Two seconds after relay 33 is energized, armature 88 breaks from contact 68, there- .by de-energizing relay 28. and causing armature makes contact with 89, thereby energizing relay '28. Relay 35 now being ie-energized, armature.

l4 breaks from contact [8, extinguishing the B street green and the A'street red light and makes contact with 15, thereby lighting the yellow light. Armature makes contact with 82, thereby energizing relay 32. Two seconds after relay 32 is energized, armature 55 breaks from contact 88, de-energizing relay 29 and makes contact with 61, energizing relay 34. Relay 34 now turns on the A street green and theB street red lights and extinguishes the yellow light. 'I'his cycle now re- CONNECTION XVL-If it is desired to disconnect the traflic actuated means in A street and leave connected the traflic actuated means in B street, this may be accomplished by leaving the switches as shown in Fig. 2 and Fig. 2a of the drawings,

except that switch Ill'lv is operated to the position making contact with 4|, 42, and 42. Under this condition, right of way will remain on A street for a period of 30 seconds regardless of actuation of an A street ramp, and remains on B street fora period dependent upon the actuation of the B street ramps, varying from 10 to 30 seconds. Right of way "is given to B street following a yellow period only if a 3 street ramp has been actuated since 10 seconds before B street last lost right of way. In the CONNECTION XVII.Likewise switch I08 may be operated to its other position instead of switch I01, thus producing the effect described in Connection XVI except that the condition on A street and B street are interchanged.

The circuit is so arranged that manual control may be used. This is accomplished as follows through the use .of switches I05 and I06. To show a yellow light in both streets, switches I05 and I06 are operated to such a positionthat the blades make no contact. Thereupon, relays 34 and 35 are de-energized and the yellow light is lighted through contacts II, 12, I4, and 15. To light the A street green and the B street red lights, the blades of switch I05 are thrown to the left contacts thereby energizing relay 34 through wires I66 and I61, extinguishing the yellow light by interrupting its circuit between H and I2, and lighting the A street green and the B street red through the contacts made between armature 1| and contact 13. To light the B street green and the A street red lights, the blades of switch I06 are thrown to the right contacts, thereby energizing relay- 35 through wires I64 and I65. Armature 14 breaking from contact 15 opens the yellow light circuit, and armature 14 making contact with I6 lights the B street green and the A street redlights.

The circuit is so arranged that the yellow light can be turned on and all other signal lights ex-' tinguished either by closing switch I02 shown in Fig. 2, and Fig. 2a or by applying power to the two wires marked To fire headquarters. This feature is introduced to provide for emergency control either at the control panel at the intersection, or from a distant point. Either of the last two described operations energize relay 36, thereby breaking contact between I00 and IN and 98 and 99', thus deenergizing relays 34 and 35, causing armature 'II to make contact with 12 and armature 14 to make contact with I5, thereby lighting the yellow light and preventing any other signals from being lighted except by man-' ual operation as previously described. Closing switch I02 energizes relay 36 through wire I2I, switch I02, wire Ill and I69, the coil of relay 36, wire I68 and I10, switch I02 and wire H6.

The circuit is so arranged that if the right of way is yielded by one street due to the operation of the 30 second relay and not due to the operation of the second relay, then the relay which is energized by the ramps in the street which is just losing right of way, that is, relay 26 for A street or relay 21 for B street is not de-energized as it is when the right of way is yielded by the operation of the 10. second relay, but remains energized thus providing that the right of way return to this street immediately after a yellow period following the This arrangement is made because when the right of way is yielded by the operation of the 30 second relay, a vehicle which has operated a ramp on the street which is losing right of way has not had a full 10 second period in which to cover the distance between the ramp and the intersection and to traverse the intersection. Thus it may be stopped between the ramp and the intersection yielding by the other street;

by the red light. This circuit provides that the right of way return at the earliest permissible moment to this car without the necessity of further operation of a ramp in its street.

This effect is accomplished for A street as follows: The operation of 30 second relay 28 to release relay 32 does not de-energize relay 26 inasmuch as current is supplied through contacts 59 and 6 I If, however, the right of way is yielded by 10 second relay 30, contact is broken between 59 and 6| thus de-energizing relay 26 when relay 34 is deenergized.

Where, in this description, 9. change of switch positions is indicated to produce a change in the efiect on the signal means of actuation of an A street trafiic actuated means, and another change of switch positions is further indicated to produce the same change in the effect on the signal means of actuation of a B street traflic actuated means, it is obvious that both changes in switch positions could be made simultaneously, thus producing the aforesaid change in effect on the signal means by traffic actuated means in both or either streets.

The term traflic actuated means or the like is used in this specification and in the appended claims in the sense of trafi'lc actuatable means or means adapted to be actuated by successive vehicles repeatedly. v

Whereas, I have described a single street traffic control system embodying my invention, it is obvious that other arrangements embodying my invention may be constructed, and I do not wish to limit myself to the particular embodiment described herein. I aim in the appended claims to cover all modifications which are within the scope of my invention.

What I claim as new and desire to. secure by Letters Patent is: h I

1. In a highway trafiicslgnal system for intersecting lanes, right of way signals for the respective lanes, traffic agtuated means in each lane, a'timing device to regulating the periods of operation of the signals, in accordance with trafiic demand among the intersecting lanes as revealed by the traffic actuated means, including means for maintaining periodic operation of the signals alternately in absence of actuation of the traflic actuated means. 2. In an automatic trafiic signal system for intersecting traffic lanes in combination, a pm rality of signals at the intersection, electric control means for periodically operating the signals including a plurality of interlocking relays connected in circuit for selectively operating the signals at predetermined intervals in absence of traffic and traffic actuatable means for completing the circuits to certain of the relays whereby the period of operatio'n'of the signals may be changed by the passage of traffic in either of the lanes.

3. A signal system for intersecting traflic lanes comprising means for indicating right of way signals for .the respective lanes, means actuated by traffic in the respective lanes to operate the signal indicating means, means connected with the signal indicating means and the traffic actuon said other lane and the operation-of the signal so as to interrupt a. continuous trafiic stream on said one lane and means for operating the signal means in absence of actuation of the trafi'ic actuated means in a periodic time sequence and traiiic lane sequence.

4. A system of trafiic control for use at the intersection of trafiic lanes, comprising a. traffic actuated means in each lane, signal means including a caution signal and stop and go right of way signals for the respective lanes, and a control mechanism interposed between said trailic actuated means and said signal means for causing a caution signal to show in all lanes when no trafiic is immediately approaching the intersection, said control mechanism including means for causing a go signal to indicate right of way to that one of the intersecting lanes upon which traffic shall first approach said intersection and to cause said go signal to remain with this lane for a predetermined period after each vehicle thereon shall approach the intersection within a predetermined limiting period, means for causing the go signal to be withdrawn from said lane when no vehicle approaches during one of the first mentioned predetermined periods, means for maintaining the go signal when vehicles continue to approach at intervals of shorter time than said first mentioned predetermined period and withdraw right of way from said lane at the expiration of the second mentioned predetermined period, means for granting right of way immediately or after.

a caution period to that traffic lane upon which a vehicle approached said intersection subsequent to the approach of the vehicle which caused rightof way to be granted to the lane from which it was last withdrawn.

5. In a trafflc signal system, the combination with stop and go signals at a highway inter-' section, of means including an instantaneous relay for each highway and operated by a vehicle' on its highway, an instantaneous signal relay for each highway, each connected to control a stop and go signal to accord right of way to its associated highway only, a delayed action relay for each highway connected with the instantaneous relays of that highway to time such accord of right of way, and means including an operating circuit for each signal relay interrupted by operation of the other signal relay and also interrupted by operation of its'connected delayed action relay at the end of the time period of the latter to prevent the simultaneous operation of both instantaneous signal relays to operate stop and go signals.

6. In a traific signal system, the combination with stop, go and 'caution signals at a highway intersection of means including an instantaneous 6o relay for each highway connected to be energized by a vehicle onits highway, an instantaneous signal relay for each highway, each connected to control a stop and g0 signal to accord right bf way to'its associated highway only, adelayed 65 action relay for each highway connected with the instantaneous relays of that highway to operate the signal relay responsive to operation fof the traflic actuated relay to maintain right of ,way accorded only to that highway for a pre- 70 {determined time period and to release said siginal relay at the end-of said time period, and imeans for actuating the caution signal when Pneither signal relay is so operated. 7. In a highway trafl'ic signal system for inter- 7 secting streets comprising a plurality of signal an intersecting street for interrupting the predetermined period and for causing the desired signal to be given to said intersecting street and 10 timing means for reestablishing the signal on the first street after a predetermined interval.

8. In a highway intersection traflic signal system comprising a plurality of right of way signal lights for the respective intersecting highways, 15 a mechanism having a predetermined time rate of operation for normally operating the signal lights in sequence and controlling the duration of the periods of operation of the signal lights in the absence of traffic, said mechanism in- 0 cluding means for changing the normal duration of the period of operation of the signal lights in response to traiiic approaching the intersection.

9. In a highway signal system for intersecting 25 streets having a signal means for each street for indicating right of way, means for receiving traffic presence indications from each street, including means for retaining the effect of such indications, and means for retaining the eflect 30 of the first such traflic indication until the signal means has indicated the right of way signal to that street for a continuous predetermined period after the last received traflic presence indication from that street, and a timing mecha- 35 nism to time the continuous predetermined period through which the signal means indicates the right of way signal after the last received traflic presence impulse, said timing mechanism having an operating circuit and adapted to be 0 energized to time its period by completion of said operating circuit and 'to reset to restart its timing responsive to interruption of said operating circuit, and a control switch in said operating circuit and opened by each operation of 45 said traflic indicating means to interrupt said operating circuit responsive to each trafilc presence indication.

10.- In a,highway signal system for intersecting streetshaving a signal means-for each street for indicating right of way; means for receiving traflic presence indications from each street, in-

cluding means for retaining the efiect of such indications, and means for retaining the efiect of the first such' traflic indication until the sig- I nal means has indicated the right of way signal to that street for a continuous predetermined period after the last received trafilc presence indication from that street, a timing mechanism to time the continuous predetermined period so" through which the signal means indicates the right 01' way signal'ai'ter the last received trafflc presence impulse, said timing mechanism having an operating circuit and adapted to be energized to time its period by completion of said operating circuit and to reset to restart its timing responsive to interruption of said operating circuit, and a control switch in said operating circuit and opened by each operation of said trailic indicating means to interrupt said operating circuit responsive to each traflic presence indication, and a second timing mechanism to control the maximum length of the time period which one street may be given the right of way indication by the signal means before the intersecting trafiic lanes,

right of way indication is given to the other street.

11. In an automatic traffic signal system for in combination, a plurality of signals at the intersection, electric control means for periodically operating the signals including a plurality of interlocking relays connected in circuit forselectively operating the signals at predetermined intervals, and trafiic actuated means for completing the circuits to certain of the relays whereby the period of operation of the signals in both streets may be changed by the passage of trafiic in either of the lanes.

12. In an automatic intersecting trafiic lanes, in combination, a plurality of signals at the intersection, electric control means for periodically operating the signals including a plurality of interlocking relays connected in circuit for selectively operating the signals at predetermined intervals in absence of traflic, and traffic actuated means for completing the circuits to certain of the relays, whereby continuous traflic in one lane shall be interrupted to permit passage of a vehicle in an intersecting lane within a predetermined time after the arrival of such vehicle, but only for a predetermined period to permit passage of said vehicle.

13. In a vehicle actuated highway traflic signal system comprising a plurality of signal lights for intersecting highways, a mechanism having a predetermined period of operation for normallights in sequence and ly operating said signal duration of the periods fixing the sequence and of operation of the signal lights in absence of trafiic, said mechanism including means for changing the duration of the period and the sequence of operation of the signal lights in response to trafiic approaching in at least one highway.

14. In a highway trafl'ic signal system com? prising a plurality of signal lights for intersecting highways, a mechanism having a predetermined period of operation for normally oper ating said'signal lights and fixing the sequence and duration of the period of operation of the signal lights in absence of trafiic, said mechanism including means for changing the duration of the period and the sequence of operation of the signal lights in response to trafiic approaching in at least one highway, and means for preventing right of way signals being given to traflic simultaneously from two or more lanes.

15. A trafiic signaling apparatus for two interfering traflic lanes and having, in combination, right of way indicating means for the respective lanes, trailic actuated controllers, one in each of said lanes, a timing mechanism for limiting right of way indication in either lane between an original, predetermined, minimum interval and a predetermined,"maximum inter-.

val of time by actuation of the ,controller forof way indication between said lanes, said transfer of right of way being dependent upon actuation of a controller in either lane before the end of any minimum interval indication or of any continuously prolonged minimum interval indication of right of way, less than the maximum, begun in the other lane by the other controller.

traflic signal system for '16. In a. traffic signalling system for interfering trafilc lanes, having means for displaying right of way signal indications, signal timer means for normally cyclically displaying said right of way indications successively to the several trafiic lanes, a vehicle responsive device on one of said lanes, and erable by response of said device to a vehicle onsaid one lane, to render said timer ineffective to normally display said indications, and to give the right of way indication to the said one lane.

1'7. In a traflic system for interfering lanes, a right of way indicating means displaying said indication to each of said lanes for predetermined times for the control of trafiic, a vehicle actuated device in one of said lanes, and means operable upon actuation of said device when the said lane has the right of way for cooperating with the first named means to extend the? time of display of said indication to the said one lane beyond the time predetermined by the first named means.

18. In a traffic system for intersecting streets, a right of way indication, means displaying said indication to each of said streets for predetermined times for the control of traflic, a'vehicle actuated device in each street, and means operable upon an actuation of the device in the street having the right of way for cooperating with the first named means to extend the time of display of said indication beyond the time determined by the first named means.

19. In a traffic system for intersecting streets, 2. right of way indication, means displaying said indication to each of said streets for predetermined times ior the control of traffic, a vehicle actuated device in each street and means 0perable upon an actuation of the device in the street having the right of with the first named means to extend the time of display of said indication beyond the time determined by the first named means, and means to further extend the time of display of said right of way indication upon subsequent actuations of the said device in the street having the right of way occurring within predetermined intervals of each other.

20. A device as in the preceding claim further provided with means for limiting such extended time of display of the right of way to the said street to a predetermined maximum time.

, 21. A right of way indicating device for intersecting main and cross thoroughfares, controller means for normally periodically shifting the right of way indication from one thoroughfare to the other, means to arrest the operation of the controller so as to maintain the right of way indication on the main thoroughfare,and meansv including a vehicle operated device on the main thoroughfare to operate the controller arresting means to maintain the right of way indication on the main thoroughfare, and means operable within a predetermined time after the said arresting means has functioned to re-establish the periodic control of the indication bythe said controller.

22. In a traffic signal system arranged at the intersection of a main highway and across road for regulating traflic, saidsystem comprising a plurality of signal circuits, one circuit including a signal to indicate stop and another to indicate go, a time control selective switch means normally associated withsaid circuits for alternately opening andclosing same cyclically, vehicular actuated means for rendering the said super control means op way for cooperating time control selective switch means temporarily inactive and to retain said go signal for the main highway, and a second time control switch means operable within a predetermined time after said selective switch has been rendered inactive to destroy the efiicacy of the said vehicle actuated means to retain the "go". signal for one complete cycle.

23. In a tra-filc signaling system arranged at the intersection of a' main highway and a crossroad for regulating trafllc, the system comprising-a plurality of signal circuits, said circuits including a stop signal for each of said highways and a go signal for each of said highways, a time control selective switch means nor mally connected to the said circuits for alternately opening and closing same cyclically, vehicular actuated means for rendering the said time controlled selective switch means temporarily inactive and to retain the said go signal for the main highway, and a second time control means, ineifective during the display of the stop signal to the main highway and operable to destroy the eflicacy of the said vehicular actuated means to retain the "go signal for one complete cycle within a predetermined time after the said main highway go signal is retained energized through the arresting of the said selective switch means after the extinction of the display of the said last sto signal.

24. In a signal system for intersecting traffic lanes the combination of right of way signals for the respective lanes, trafilc actuatable means in each of the lanes, electro-magnetic means for opcrating the respective signals, electro-magnetic control means operated by actuation of the respective traffic actuatable means and an electric time controlled mechanism conmwted in circuit between the electro-magnetic signal operating means and the electro-magnetic control means of each lane to operate the right of way signals alternately in a .predetermined time sequence in absence of actuation of said electro-magnetic control means and including means to interrupt the predetermined time sequence for a predetermined time interval in either lane responsive to actuation of the electro-magnetic control means for the latter lane.

25. In a trafiic signal system for intersecting highways, stop and go signals for each of the respective highways, means including an instantaneous relay for each highway operated by passage of a vehicle on its highway, an instantaneous signal relay for each highway to operate a stop and go signal to accord right of way to its associated highway only, and a plurality of delayed action relays for each highway connecting the instantaneous relays of that highway to control the time of such operation of the -stop and go signals by the signal relay responsive to actuation of the traflic operated relay and means controlled by said delayed action relays for interlocking the instantaneous signal relays so as to prevent the operation of more than one signal relayat the same time.

26. In a traffic signal system for intersecting lanes, a plurality of right of way signal means for the respective lanes, time controlled means for operating the signal means normally in se-- quence at periodic intervals, means responsive to a. vehicle one one of the lanes for changing the period of operation of one of said signal means by said time controlled means, and means forming a partot said time controlled means for prelanes, a plurality of go controllers in accordance with venting operation of right of way signals simultaneously in more than one lane.

27. In a. trafllc signal system for intersecting signal means for the respective lanes, traflic actuated means for the respective lanes, timing mechanism connected with the tramc actuated means and the signal means to operate the signal means in one lane for a predetermined period, said timing mechanism including means for interrupting the first signal and operating the signal of an intersecting lane at the end of said period for another predetermined period in absence of traffic on said intersecting lane and means for restoring the go signal to the first lane at the end'of said second period in the absence of tramc thereon, and means responsive to actuation of said traific actuated means in said intersecting lane to prolong said second period.

28. In a. vehicle actuated highway intersection trafiic signal system comprising a plurality of right of way signal means and a caution signal, trafllc actuatable means in the respective highways, timing mechanism having a'predetermined time rate of operation for normally operating alternately in a time sequence the right of way signal for one highway and the caution signal in absence of traflic actuation, said mechanism including means for changing the normal sequence of operation of the signals to include op-- rate of operation for normally operating saidv lights in sequence and controlling the duration of the periods of operation of the lights in absence of traflic, vehicle actuatable means in at least on highway, said mechanism including means for increasing the normal duraton of the period of operation of the signal light on said one highway in response to vehicle actuation thereon. v

30. Ina traflic signaling apparatus for two interfering trafllc lanes having right of way indicating'means for the respective lanes, trafiic actuatable controllers in the respective lanes, and time controlled mechanism for operating the indicating means in the respective lanes alternately for variable time periods in response to actuation of the respective controllers in accordance withtrafiic demand; said mechanism including timing-devices individual to the respective lanes to limit operation of the right of way indication in each lane between an original predetermined minimum time interval and a greater predetermined max um time interval by actuation of the controller for such lane.

31. In a traflic signaling apparatus for two interfering trafllc lanes having right of way signals for the respective lanes, traffic actuatable controllers in the respective lanes, and time controlled mechanism for operating the signals in the respective lanes alternately for variable time periods in response to actuation of the respective traflic demand, said mechanism including switching mechanism having alternate switch positions for energizing the respective right of way signals, two timing devices individual toeach lane one having a relatively short predetermined minimum time period and the other having a considerably longer predetermined maximum time period, and connections between said switching mechanism and said timing devices to energize both said two devices of either one lane for timing in the switch position energizing the right of way signal for said one lane, and means including connections timing devices to control actuated by said two said switch mechanism to hold the latter in the last mentioned position during the time periods of the respective two timing devices and at the of the latter devices mechanism from said last transfer to the other potirning device havto release the switch mentioned position for sition, each said minimumw ing a connection with the traflic actuated 0011- troller of its associated lane and being adapted to reset its timing period responsive to actuation of such controller.

- 32. In a trafiic signaling apparatus for two interfering lanes having a caution signal and right of way signals for the respective lanes, trafflc actuatable controllers-for the respective lanes, and time controlled mechanism for operating the right of way signals in the respective lanes alternately for variable time periods in response to actuation of the respective controllers in accordance with traflic demand, and operating the caution signal for a brief period intervening the alternate right of way signal periods, said mechanism including timing devices individual to the respective lanes to control operation of the right of way signal in each lane individually so as to limit such operation between an original predetermined minimum time interval and a greater maximum time interval by actuation of the controller for such lane, and additional timing devices for the respective lanes connected to be operated by the respective first named timing devices at the end of timing interval of the latteronone lane to operate said caution signal for a brief time interval and at the end of the last named time interval to initiate such control of the right of way signal by the timing devices for the other lane.

33. In a trafiic signaling apparatus for two interfering trafiic lanes having right of way signals for the respective lanes, trafiic actuatable controllers in the respective lanes, and time controlled mechanism for operating the signals in the respective lanes alternately for variable time periods in response to actuation of the respective controllers in accordance with traflic demand, said mechanism including switching mechanism having alternate switch positions for energizing the respective right of way signals, two timing devices individual to each lane onehaving a relatively short predetermined minimum time period and the other having a considerably longer predetermined maximum time period, and connections between said switching mechanism and said minimum timing devices to energize said minimum device of either one lane for timing in the switch position energizing the right of way signal for said one lane, and switching mechanism and said maximum timing devices and including switch means operated by the respective controllers to energize the maximum timing device of either one lane responsive to traflic actuation on the other lane in the right of way switch position of said one lane, and

means including connections actuated by saidsive to actuations of connections between. said nism to hold the position during the time periods of the respective two timing devices and at the end of the period of either of the latter devices to release the switch mechanism from said last mentioned position for transfer to the other position in response to actuation of the controller for the other lane, each said minimum timing device having a connection with the tramc actuated controller of its associated lane and being adapted to reset its timing period responsive to actuation of such controller.

34. In a trafilc-signaling system, the combination of signals operable to indicate the right of way to several intersecting streets successively and for simultaneously indicating stop to the others, signal switch mechanism operable to several positions to energize the necessary signal combinations in each of its several positions granting the right of way to said intersecting streets respectively, said mechanism including switches operated for so energizing the several signals in the respective right of way positions and an interlocking connecting between said switches to prevent concurrent operation of the switches for the respective right of way signals, vehicle-actuated and timing switches for the respective streets and operable respectively responsive to actuations of said vehicle-actuated devices in the intersecting streets to control the positioning of said signal switch mechanism and for maintaining said signal switch mechanism in a selected position granting right of way for a minimum time period responsive to a single actuation of a vehicle-actuated device.

35. In a traflic signalling system, the combination of signals operable to indicate the right of way to several intersecting streets successively and for simultaneously indicating stop to the others of said streets, signal switch mechanism operable to several positions to energize the necessary signal combinations in each of its several positions granting theright of way to said intersecting streets respectively, said mechanism including switches operated for so energizing the several signals in the respective right of way positions and an interlocking connection between said switches to prevent concurrent operation of the switches for the respective right of way si'gnals, vehicle-actuated devices in each of said streets, and timing switches for the respective streets and operable respectively responsaid vehicle-actuated devices to operate said signal switch mechanism to assume a predetermined position granting right of way responsive to an actuation of a vehicleactuated device in one of the intersecting streets, to hold said signal position for a predetermined minimum time period and to hold said signal switch mechanism in said position for a predetermined maximum time period responsive to successive actuations of said vehicle-actuated device, said actuations being spaced from-each other a time period less than said minimum period.

36. In a traificesignaling system the combination of signals positioned at the intersection'of two thoroughfares and operable to alternately indicate the right of way to each of said thoroughfares respectively while indicating stop to the other, vehicle-actuated devices in each of said thoroughfares, relays responsive to actuations of said vehicle devices in fares respectively and operable to record the preslatter in the last mentioned devices in each of said streets,

switch mechanism in said the thoroughence of vehicles at the intersection on the thoroughfares nothaving the right of way, a timing ated responsive to the joint action of said timing switches to energize said signals to maintain the right of way on one thoroughfare for a predetermined minimum time period by one timing switch responsive to a single actuation of a said vehicle-actuated device in that thoroughfare and to transfer the control of said signals to the second of said timing switches at the end of this period, said signal switch mechanism including switches for so energizing the signals to grant right of way to the respective thoroughfares and an interlocking connection'between said switches to prevent concurrent operation of the switches for the respective right of way signals.

37. In a traihc signalling system for two intersecting streets, a right of way signal for one of the streets, a switch operable for energizing said signal, a trafiic actuated device for said one street, and a timing switch for said one street, a second right of way signal for the second street, a second switch operable for energizing said sec- -ond signal, a trafiic'actuated device for said second street, and a timing switch for said second street, and operating mechanism for the signal switches and having two alternate interlocked positions, one for operatingonly the first mentioned switch to accord right of way to the first street and the second position for operating only the second switch to accord right of way to the second street, and connections between said mechanism and the two sets of timing switchesand traii'ic actuated devices for the two streets to control shift of said mechanism from either one position to the other to accord right of way responsive to actuation of the respective devices in the street not having right of way, and to maintain said mechanism for a minimum time period by one timing switch in either one position to which said mechanism is so shifted in response to a single actuation of one trafiic actuated device and to release control of said mechanism to the other traflic actuated device at completion of the time period of the last mentioned one timing switch for shift from the last mentioned one position of said mechanism to the other position responsive to actuation 'of said other traific actuated device.

38. In a trafiic signalling system for two intersecting streets, a right of way signal for one of the streets, a switch operable for energizing said signal, a tramc actuated device for said one street, and a minimum period timing switch and a maximum period timing switch for said one-street, a second right of way signal for the second street, a second switch operable for energizing said second signal, a tramc actuated device for said second street, and a minimum period timing switch and a maximum period timing switch for said second street, and operating mechanism for the signal switches and having two alternate interlocked operating positions, one

second position for operating only the secondswitch to accord right of'way to the second street, and connections between said mechanism and -respective minimum and maximum timing switches for one street and from the traflic actuated device for the second street to shift said mechanism from said one position to said second position responsive to trailic actuation of the second traffic actuated device and to completion of timing by either one of said one minimum and said one maximum timing switches, an operating connection for said mechanism from the minimum and maximum timing switches for the second street and from the traffic actuated for said one street to shift said mechanism from said second position to said one position responsive to traffic actuation of said one device and to completion of its timing by either one of said second minimum and said maximum timing switches, and a controlling connection between the traific actuated device on each street and the minimum timing switch for that street to interrupt completion of the timing of the minimum timing switch to maintain right of way beyond the minimum period and up tothe maximum period by repeated trafiic actuations.

39. A traflic control system for use at the intersection of a plurality of trailic lanes, comprising a vehicle-actuated means in each lane placed for actuation by vehicles approaching the intersection; a caution signal and right of way signal means for each lane, a controlling means interposed between said vehicle-actuated means and said signal means, said controlling means including means to operate a right of way signal to that lane from which vehicles shall first approach said intersection, means for maintaining said right of way until a vehicle approaches said intersection from another of said intersecting lanes and holding said right of way thereafter for a predetermined period after the approach of each vehicle on the first lane within another predetermined limiting period, means to withdraw said right of way upon the expiration of one of. the first mentioned predetermined periods after such approach of a vehicle in said other lane when vehicles cease approaching on said first lane for an interval greater than said first mentioned predetermined period, and means for withdrawing the right of way at the expiration of the second mentioned predetermined limiting period after such approach of a vehicle on said other lane when vehicles constantly approach said intersection at intervals less than proached said intersection after right of way was granted to the first lane and to provide a period of caution signal opera-tion between such withdrawal and such grant of right of way.

HENRY A. HAUGH, JR.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7409286 *Jun 24, 2002Aug 5, 2008Jorge Osvaldo AmbortApplication for diminishing or avoiding the unwanted effects of traffic congestion
Classifications
U.S. Classification340/923
International ClassificationG08G1/08, G08G1/07
Cooperative ClassificationG08G1/08
European ClassificationG08G1/08