US 2850717 A
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Description (OCR text may contain errors)
P 2, 1958. G. A. WISWELL 2,850,717
TRAFFIC CONTROL SIGN 4 Sheets-Sheet 1 Filed Aug. 19, 1955 INVENTOR. GRANT A. W/SWELL ATTORNEY Sept. 2, 1958 e. A. WISWELL TRAFFIC CONTROL SIGN 4 Sheets-Sheet 2 Filed Aug 19, 1955 INVENTOR. GRANT A. W/SWELL By f A TTOR/VE Sept. 2, 1958 e. A. WISWELL 2,850,717
TRAFFIC CONTROL SIGN Filed Aug. 19, 1955 4 Sheets-Sheet 3 It!!! rllappalllazlpalaaar l .r, l3] ZL ATTORNEY Sept. 2, 1958 e. A. WISWELL TRAFFIC CONTROL SIGN 4 Sheets-Sheet 4 Filed Aug. 19, 1955 n EFF mar INVENTOR.
GRANT A. W/SWELL "flwm 'ATTORNEX TRAFFIC CONTROL SIGN Grant A. Wiswell, Burlingaine, Calif.
Application August 19, 1955, Serial No. 529,515
9 Claims. (Cl. 34ll84) This invention relates to an improved traffic control sign.
At rush hours when trafiic is at a peak, it is often desirable to impose traffic regulations that are difierent from those obtaining when there is less trafiic. For example, on some streets, usually at intersections, it is necessary to forbid left turns during peak hours; yet, during off-peak hours it may be desirable to permit left turns. Obviously, it requires considerable personnel to change the left-turn rule by Setting up and removing a series of signs each time the change is made, which may be several times a day; so there has long been a need for a special type of traffic-control sign that can be changed by remote control.
No sign structure heretofore known has given satisfactory results as a traflic changeover sign. For example, some cities have used neon signs with the glass tubing positioned in front of a dark background. During the peak hours the lighted signs display the legend No Left Turn (or whatever specal rule is to be in force); when the peak hours have passed, the signs are turned off. When the sign was lighted, the legend Was easily read, provided that it was equipped with visors to reduce sun wash-out. The trouble was that when the sign was not lighted, the glass tubing or its shadow was still visible, and the legend stood out clearly under certain light conditions; so motorists became confused and doubtful whether they could turn left or not. This doubt caused hesitation and has led to accidents. In
other words, one trouble with prior art signs has been that the legend was not fully obscured during off-peak hours. The present invention solves this problem by providing a sign in which the legend is fully obscured when the rule is not in force.
Another problem common to prior art signs was that the peak-hour legend was always off during power or circuit failures. Referring for example to the neon signs, which represented the most advanced state of the prior art, the neon sign would not be lighted during a power failure; so, where a neon sign said No Left Turn at peak hours and was unlighted at other times, a power failure during rush hours caused the trafiic to become snarled, and it sometimes took a great deal of effort by many policemen to straighten out the result of a few minutes of power failure. The present invention has solved this problem by displaying the peak-hour legend if the power fails. Thus, under the conditions related above, the present invention would indicate No Left Turn during a power failure or local circuit interruption.
This is the correct legend for peak-hour traffic, and if it happens to be displayed during off-peak hours (due to a power failure), the trafiic is subjected to only a minor annoyance, While the disappearance of No Left Turn during peak tratfic can cause a major problem.
In cities where power failures are a negligible hazard, power can be saved by reversing the wiring of the sign of the present invention and using it in the opposite manner.
Trafiic control signs heretofore in use have also suf- Patented Sept. 2, 1%53:
fered from poor visibility. In many signs the legend has been partly obscured by reflected light on the sign or on a front panel of glass or plastic sheet that protects the sign. Also, signs placed high above the road have been awkward to read because the automobile drivers are well below the sign. The present invention has solved these problems by positioning the sign at a downward tilt and by tilting the window which keeps the sign dustproof at a different angle. Not only is the maximum visibility assured, but reflection is eliminated, and the sign and window are protected to a great extent from the obscuring effects of rain and dust.
Other problems have been solved by this invention. It provides a very dependable operating mechanism, characterized by its simph'city and by the fool-proof nature of its construction, by its ability to operate over long periods of time without maintenance, and by a structure which eliminates disruptive forces that would tend to damage the apparatus.
As has been implied, the objects of the invention are the solution of the problems discussed above, and it has solved them by providing a new type of shutter-controlled sign. In the preferred form, when the power is on, the shutter is closed and completely covers the sign, the shutter being moved by a solenoid operating through a novel rack-and-pinion system. Whenever the power is off, the solenoid is de-energized and the shutter is open.
Other objects and advantages of my new device will appear from the following description of a preferred embodiment thereof, presented in accordance with 35 U. S. C. 112.
In the drawings:
Fig. 1 is a view in perspective of a traffic control sign embodying the principles of my invention, shown installed above a traffic signal. The shutter is in open position, disclosing a legend.
Fig. 2 is a view similar to Fig. 1 showing the shutter in closed position with the legend obscured.
Fig. 3 is a view in front elevation and partly insection taken along the line 33 in Fig. 4, the shutters being open.
Fig. 4 is a view in side elevation and in section taken along the line 4-4 in Fig. 3.
Fig. 5 is a View in section taken along the line 55 in Fig. 4.
Fig. 6 is a fragmentary View in front elevation and partly in section of the shutter-operating mechanism, shown in its normal, unenergized, shutter-open position.
Fig. 7 is a view in elevation of the right-hand portion of Fig. 6, shown in its energized, shutter-closed position.
Fig. 8 is a plan view of the portions shown in Fig. 6.
Fig. 9 is a view in section taken along the line 99 in Fig. 6.
Fig. 10 is a view in section taken along the line 1010 in Fig. 6.
Fig. 11 is a view similar to Fig. 3, but with the shutters closed.
Fig. 12 is a view in elevation of a modified form of shutter-operating mechanism.
Fig. 13 is a view similar to Fig. 4, but showing the device in its shutters-closed position, as in Fig. 11.
Fig. 14 is a view in side elevation and partly in section of a modified form of device in which two devices like the one of Fig. 1 are disposed back to back in the same housing.
Fig. 15 is a view in front elevation, partly cut away, of a modified form of the invention in which there are two alternative legends, one of which shows when the shutters are closed, the other of which shows when the shutters are open. The device is here shown in its shutters-open position.
the present invention may be mounted atop a trafiic "signal 21 so as to show its legend during'peak-hours,
andFig. 2 shows how'the sign appearswith thelegend obscured at other times. By way of example, the legend shown is No Left Turn, although any other legend -may be used. Inthese-drawings the sign 2% is mounted 'on' a T-bracket 22 which helps to support the traffic signal 21, along with another bracket 23, both brackets 22 and 23 being secured to a vertical standard 24. Increased stability'is given the sign by a .U-bracket 25 which is. secured to the T-bracket 22 and is riveted or bolted to the sign 29. Other arrangements may, of
section, the sign 20 may be placed beside the signal 21 instead of above it. The sign 20 may, of course, also be used where there is no traffic signal and may be used for other purposes than traffic control.
The sign 20 includes a case 34), preferably made out of aluminum or other rigid material. As shown in Figs. 1 to 5, the case 39 is boxlike but is generally trapezoidal as seen in vertical section. It has a relatively narrow imperforate base '31 with closed trapezoidal side plates 32 and 33 which inclined front edges 34 and vertical rear edges 35. The case 313 has an imperforate top plate 36, and its front face 37 comprises an open four-margined frame with a depending flange 38 at its upper end; which servesto cover the shutter-operating mechanism inside the case'30.
The metal frame 37 holds a window 49, preferably of clearplastic, in a tilted position, as shown, at an angle of about 10 from the vertical. This mounting angle eliminates reflection of light into the motorists eyes. It also helps to protect the window 49 from accumulation of dust and protects it. from rain,
The vertical rear end of the case 39 is preferably closed bya hinged closed door 41, through which access maybe had. to the interior of the case. The sign may be illuminated from-behind by fluorescent bulbs 42 "supported in the door 41 on brackets 43 or on a unitary rack for easy replacement,or the sign maybe front-lighted, as in Fig. 17, depending on the location and use of the sign." Any type of lamp may be used, including the cold-cathode type, and the lamps may be tubular or scrolled.
The legend (e. g., No Left Turn) is borne on a panel 45, which preferably is oftranslucent plastic, such as Lucite, with the background blacked out by paint or otherwise. The panel 45 is supported in a stationary position by an interior frame 4-6, which is supported in the case 30, as'by suitable brackets. The sign 45 may be either back-lighted bythe bulbs 42, or frontlighted by. ambient light or exteriorly' mounted bulbs 47 as in Fig. 17. In this latter arrangement an interior light base is not required. T it will be clearly visible because the Lucite will pick up light, and "the legend will therefore stand out clearly against the dark background. The frame 46 is provided with channeled sides 48,'to the back of which the panel 45 maybe bolted and within which are mounted a pair of shutters 50 and Lin front of the sign panel 45.
The lower end of the frame 46 lies adjacent thefrono window and the frame 46 is tilted so that the panel is held at about the angle of 5 to the vertical, being thereby spaced away from the window 40 at its upperend. This has many advantages. It gives the proper angle of vision, eliminates secondary reflection from the Lucite, and prevents the outer Window 40, if made from course, be. employed; for example where the trafiic signal 21 is suspended in the center of a street over an nter- 4 7 plastic, from being forced in by wind against the shutters 50, 51.
Each shutter SQ or 51 may comprise a light-weight sheet of plastic or aluminum cut out to provide a plurality of openings, or may be assembled from strips spaced to provide the openings, the number of openings depending on the number of lines taken up by the legend. Where a three-line legend is employed, as shown in the drawings, the front shutter has two openings 52 and 53, and the rear shutter '51 likewise has two openings 5 5 55. Each opening 52, 53,54, and 55 may be divided by one or more vertical stabilizing members 56, 57 preferably integral with the shutter sheet.
One shutter (in this instance, by way of example, the
front shutter 5%)) is normally positioned so that its lower edge rests on or adjacent the bottom edge of the frame channel when the shutter 50 is in its normal, open position. The other shutter 51 is positioned so that in its open position its upper edge 59 lies against'or adjacent the upper edge of the frame channel 48.
The front shutter openings 52 and 53 are separated by a horizontal opaque strip 60 approximately half as high as either opening 52 or 53. Its upper and lower margins 61 and 62 are the same height as the strip 60. Similarly the rear shutter openings 54 and 55 are separated by an opaque strip 63 the same height as the strip 60 and are bounded by upper and lower margins 64 and 65 of the same height. All these strips and margins may be integral portions of the shutter sheets or may be assembled from strips fastened together, The legend on the panel 45 is spaced on lines that properly register with these shutters.
-When the shutters 5i and 51 are in open position (see 'Figs. 3 and 4) the upper margin 61 of the front shutter 59 overlies the center strip 63 of the rear shutter 51; and the center strip 60 of the front shutter 50 overlies the lower margin 65 of the rear shutter 51; Thus, the legend is visible; in the example, the word No in the illustrated sign is visible through the opening 54 in the rear shutter 51, between the upper margin 64 of the rear shutter 51 and the superimposed upper margin 61 of the front shutter 50 and the rear center strip 63. Similarly, the word .Left is visible through the aligned openings 52 and 55; and the word Turn is visible.
through the opening 53 and the space below the lower edge of the rear shutter 51.
The panel 45 is obscured by raising the front shutter 50 an amount equal to the height of the margins 61' and 62 and strip 61) and by simultaneously lowering the rear shutter 51 the same amount. Then the legend No is covered (see Figs. 11 and 13) by the rear upper margin 64 and front upper margin 61; the legend Left is covered by the center strips 63 and 66; and the legend Turn 55 is covered by the lower margins 65 and 62. Being completely obscured, the legend will not cause anyone to hesitate or otherwise aifect trafiic.
The shutter-operating mechanism is mounted on top of the frame 46 and may also be secured to the case 30. It comprises a novel, solenoid-operated, 'rack-and-pinion device. A stationary gear housing 70 may be secured to the upper face of the frame 46. Inside the housing 70 a pinion 71, having two substantially concentric pinion gear trains 72 and 73, is mounted for rotation on a stub shaft 74. A bearing washer 75 may be employed to give adequate clearance from the sides of the housing 70. The outer gear train 72 of the pinion 71 engages a pair of racks 76, 77, which are diametrically opposite each other and extend vertically down into the frame 46. One rack 76 is attached to the front shutter 50, while the other rack 77 is secured to the rear shutter. Rotation of the pinion 71 causes the two racks 76, 77 to move in directly opposite directions, so'that when one rack 76 moves up,
the other rack 77 moves down, and vice versa. 'Thus, a
when the. front shutter 50is raised, the pre-deterrnined distance, the rear shutter 51 is lowered precisely the same distance and vice versa. a
The inner gear train 73 of the pinion 71 is mounted for engagement with'a horizontally moving rack 78, whose back and forth movement causes the vertical racks 76, 77 to move up and down. The rack 78 is moved by a solenoid 80, through a novel spring-cushioning arrangement. When the solenoid 89 is energized, the rack 78 moves to the right, from its Figs. 6 and 8 position to its Fig. 7 position, and when the solenoid 80 is de-energized, the rack 78 moves tothe left from its Fig. 7 position to its Figs. 6 and 8 position. When the rack 78 moves to the right (solenoid 80 energized) the shutters are closed, because the vertical racks 76 and 77 move the front shutter 50 up and moves the rear shutter 51 down. When the rack 78 moves to the left (because of the deenergization of the solenoid 80) the vertical racks 7 6 and 77 move in the opposite direction and open the shutters 50, 51. Thus the shutters will normally be in open position, and if the power fails, they will move to that position.
Solenoids move too quickly for a direct connection to be practicable. For the protection of the apparatus, and to make it foolproof, an indirect connection is employed. Integral with the rack 78 is a rod 81 which in its Fig. 6 position extends into abutment against a rod 82 that is part of the solenoid core 83. The solenoid rod 82 has a collar 84 at its outer end and there is a stationary collar 85 on a bracket adjacent the inner end of the rod 82, between which collars 84 and 85 a spring 86 is compressed by movement of the core 83 when the solenoid 80 is energized. This spring 86 thus always tends to urge the solenoid core 83 out of the solenoid 80 and pulls the core 83 out from the solenoid when the solenoid 80 is de-energize d, from whatever cause, thereby moving the rod 82 and impelling the rack 78 to the left.
The rack rod 81 is also provided with a collar 87 at its outer end, and compresses a spring 88 between it and a bearing member 89. If there were no spring 88, the rod 81 would simply remain in its outer position, and the rack 78 would not move. However, the spring 88 forces the rod 81 to follow the solenoid rod 82 when it is pulled in, the structure constituting a lost motion connection. Thus the solenoid core 83 is pulled sharply in, against the pressure of the spring 86, while the spring 88 causes the rod 81 and rack 78 to move less abruptly and catch up with the solenoid rod 82.
In operation, the energization of the solenoid 80 pulls the core 83 in, compressing the primary spring 86. The secondary spring 88 being previously compressed, pushes the rack 78 to the right until the rod 81 catches up with the solenoid rod 82. In doing this, the spring 88 causes the rack 78 to move across the small gear train 73 of the pinion 71, rotating the pinion 71 so that the racks 76 and 77 are moved, one up and the other down, thereby closing the shutters t 51. When the solenoid 80 is de-energized, the two springs 86 and 88 act together to move the rack 78 into the position where the shutters 50 and 51 are in open position.
An alternative form of shutter-actuating mechanism is shown in Fig. 12. The primary difference over the form discussed before is the provision of a collar 90 on the rack 78 on the opposite side of the housing 70 from the solenoid 89.v Between the housing 70 and the collar 98 a spring 91 is compressed. The opposite side of the rack 78 extends through the housing 76 and is connected to an anchor member 82, through a spring 93, under tension. Actuation of the solenoid 8i pulls in its core 82, which stretches out the spring 93. The spring 93 is more powerful than the spring 91, so the rack 78 moves to the right causing simultaneous compression of the spring 91. De-energization of the solenoid 80 permits the springs 93 and 91 to relax and thereby restore the rack 78 to the position shown in Fig. 12.
The invention is capable of many uses and of varia- 6 tions. For example, it may be desirable to have the shutters themselves serve as a sign to indicate an alternative action, so that when the shutter is open, the sign might read No Left Turn and when the shutter is closed, it might read Left Turn OK. How this may be achieved is shown in Figs. 15 and 16 where the rear shutter 151 bears the upper half of the words on its margins and center strip, the front shutter 150 bears the remaining half, and the window 140 has blacked-out areas 141 between the space where the letters are to show. The areas 1 hide the words on the shutters 150, 151 when they are open. When the shutters 150, 151 come together in the closed position, the words appear.
Another modified form of the invention is shown in Fig. 14. The sign 100 in effect comprises two signs like the sign 2i) placed back to back so that they can be read from both directions. Numbers placed on this drawing. indicate parts corresponding to those in the sign 20. The case 101 is like a combination of the two cases 30 back to back. The two sets of shutters 50, 51 require separate. solenoids and gear housing 70 for their operation, if direct action is to be obtained. By using gearing or other transfer means, a single solenoid could do the; work, but the structure shown gives less wear and better results, and the solenoids and gear actuating mechanisms are relatively inexpensive. The sign of Fig. 14 can therefore be installed at the center of an intersection over the traflic and can be read by traffic in both directions. The two solenoids 80 may be operated separately to give different results, or they may be wired to a single remote control wire and thereby be actuated simultaneously at all times.
Another modification is shown in Fig. 17 where a bracket 11% supports the panel 45, shutters 50 and 51, and their actuating mechanism, including the solenoid 80 and gear housing 70 without using the case 30 or the panel 48 or any back lighting. The light is provided by a lamp bulb 47 mounted in a reflector 111 in front of the sign. has wide application. However, for the most important intersections and other danger points, it is advisable to use the preferred construction already described.
To those skilled in the art to which this invention relates, many changes in construction and widely difiering embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the descrip tion herein are purely illustrative and are not intended to be in any sense limiting.
1. A traffic control sign, including in combination a stationary panel having a legend thereon; a pair of shutters movable in opposite directions between two positions, inone of which said legend is obscured, in the other of which said legend is visible through said shutters; a pair of racks, one connected to each said shutter for moving it; a pinion having a first gear train in mesh with both said racks, said racks being on opposite sides of said pinion so that rotation of said pinion moves said racks in opposite directions, said pinion also having a second gear train coaxial with said first gear train; a third rack in engagement with said second gear train; a solenoid, having a movable core; and spring means connecting said solenoid core to said rack, for operation of said shutter by energization and de-energization of said solenoid.
2. A trafiic control sign, including in combination a stationary panel having a legend thereon; a pair of shutters movable in opposite directions between two positions, in one of which said legend is obscured, in the other of which said legend is visible through said shutters; a pair of racks, one connected to each said shutter for moving it; a gear frame; a pinion rotatably supported by said gear frame and having a first gear train in mesh with both said racks, said racks being on opposite sides of said pinion so that rotation of said pinion moves said This structure is relatively inexpensive and racks in opposite directions, said pinion also having a second gear train coaxial with said first gear train; a third rack in engagement with said second gear train; a solenoid, having a'movable core; a spring undercompression between said third rack and saidge'ar frame; and a spring under tension means connecting said solenoid coreto said rack, for, operation of said shutter by energization and de-energization of said solenoid.
3.-A traific control sign,including in combination a stationary panel having a legend thereon; a pair of shutters movable in opposite directions between two positions, in one of which said legend is obscured,.in the other of which said legend is visible through said shutters; a. pair of racks, one connectedto each said shutter for moving it; a gear housing; a pinion supported by said housing having a first gear train in mesh with both said racks, said racks being on opposite sides of said pinion so that rotation of said pinion moves said racks in opposite directions, said pinion also .havinga second gear train coaxial with said first gear train; a third rack in engagement with said second gear train; a spring under compression between said third rack and said gear housing; a solenoid, having a movable core in line with and ordinarily abutting said rack; spring means urging said solenoid core out of said solenoid and into'operative engagement with said rack, for operation of said shutter by energization and de-energization of said solenoid.
4. A trafiic signal of the hidden message type, including in combination: a stationary panel bearing a traflic control sign with a message disposed on several lines thereof; a pair of shutters in front of said panel, generally parallel to it'and to each other, each said shutter having a plurality of vertically disposed rectangular windows therethrough, each window extending substantially the width of said sign and each window being spaced vertically from the next adjacent window by an opaque portion, the top and bottom said Windows of each shutter having marginal opaque portions respectively above and below them terminating with upper and lower edges, respectively, said pair of shutters being mounted for sliding movement between a sign-disclosing position and a sign obscu ring position, the. upper edge'of one shutter lying, in thesign-disclosing position, substantially level with the lower edge of the top window of the second shutter with the top line of said sign visible through said top window, and, in the sign-covering position, substantially level with the'upper edge ofsaidwindow, by virtue of themovements of said shutters in opposite directions so that the top marginal opaque portions of said two shutters cooperate to cover said top line, the lower edge of said second shutter similarly lying, in the sign-disclosing position, substantially level with the upper edge of said bottom Windowof said first shutter and, insign-covering position, substantially flush with the lower edge of said bottom window, and the upper edges of each other said window of said first shutter lying substantially flush with the upper edge of a window of said second shutter, in sign-disclosing position, and flush with the lower edge ofsaid last-named window in sign-covering position, so that said sign is completely obscured in the sign-covering position and is visible through the registering of said windows in said sign-disclosing position; and unitary means for. moving said shutters in opposite directions a all times between their two positions.
3 5. The signal of claim 4 wherein said opaque portions angle of about 10? to the vertical; a stationary panel supported in said housingbehind said window at an angle ofabout 5 of thevertical and bearing a traflic control sign; a pair of shutters slidably supported in said housing between said window and said panel, generally parallel to said panel and to each other, said shutters each hav ing generally rectangular openings therethrough bounded by and separated by opaque portions mounted for sliding movement in their own planes between afirst position where the opaque portions of said shutters cover said openings so that said sign is completely obscured, and a second, sign-disclosing, position reached from said first position by both said shutters moving in opposite directions so that'said openings register over said sign; and unitary means for simultaneously moving both said shutters in opposite directions between their two positions.
8. The signal of claim 7 wherein said transparent window has'blacked-out portions covering the shutter opaque portions when said shutter is open and wherein said opaque portions bear a second legend, the words of which are. split by a horizontal line with the upper half on one shutter and the lower half on another shutter, so that when said shutters are closed, said second legend shows.
9. The signal of claim 7 wherein there are: a pair of racks, one connected to each said shutter for moving it; a pinion having a first gear train in mesh with both said racks, said racks being on opposite sides of said pinion so that rotation of said pinion moves said racks in opposite directions, said pinion also having a second gear'train coaxial with said firstgear train; a third rack in engagernentwithsaid second gear train; a solenoid, having a movable core; and spring means connecting said solenoid core to said rack, for operation of said shutter by energization and de-energization of said solenoid.
References Cited in the file of this patent, UNITED STATES PATENTS