US 2069860 A
Description (OCR text may contain errors)
Feb- 9, 1937' n.1. STEWART REKOTE CONTROL SYISTEM 2 Sheets-Sheet 1 Filed Dec. 15, 1933 INVENToR .Duncan J. Stewat ,Tn mw rUL LA www Us:
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Dn In /23 ATTORNEYS Fell 9 1937- D. J. sTEwART nanou: coNTRoL'sYsTEM 2 sheets-sheet 2 yFired Dec. 15. 193s A TSN b SSS ATTORNEYS Patented Feb. 9, y1937 accanto 2.06am n PATENT ori-lcs y f J REMOTE CONTROL SYSTEM A Duncan J. Stewart, Rockford, Ill., assigner to f /Howard D. Colman, Rockford, Ill.
Appunti December 15, 1933, serial No. 102,434
The invention pertains to a`system oi' remote control and involves the transmission oi' ai, signal from a remote point, for example, from a motor4 vehicle to control a power driven mechanism such as an electrically driven door operator by means responsive to the transmitted signal.
One object of my invention is to provide a control system 4oi' the character indicated, which is simple in construction, so as to be/capable oi' being supplied at Ia relatively low cost, andvvwhichv is reliable in operation. l
Another object is to provide a control system -of the aforesaid character, including a sensitive detector element responsive to signals transmitted from a remote'point and operable to perform the thereby avoiding unintendedY or ac cidental operation. f
Thek accompanying drawings illustrater` the invention in a preferred embodiment, applied to the control of a garage door operator and utilizing radiant energy signals of a preconcerted character transmitted from amtor vehicle. It should be understood, however, that the invention is susceptible of wide application and in its broader aspects, is not limited to the use of radio signals. In the drawings: l
rFigure 1 is a perspective view illustrating schematically a power driven garage door operator adapted to be ,controlled by means of a signal transmitted from a motor vehicle shown in approaching relation to aV garage.`
Fig. 2 illustrates a time chart showing the sequential operation of various parts of the control mechanism with respect to a transmitted ,signal cfa preconcerted character.
Fig. 3 is a schematic view partially in perspective showing the transmitting and receiving mechanismslwith an electrically driven door operator connected with the receiver, the door operator being shown schematically.
In one aspect, my invention is an improvement upon the selective signalling apparatus of the ,patent to Howard i). Colman, No. 1,760,479, dated May 27, 1930. Generally stated, the improvement resides in the simplicationlof the transmitting and signal responsive control mechanisms. Thus, according Ytomy invention, the transmitter may be of a' slmplled character, involving merely the use of amanually operable switch in place of a mechanically timed sending mechanism; and the control mechanism operating in response to theI received signal involves a simple motor driven device whose operation is initiated upon the receipt yof -the initial impulse'of ythe transmitted signal, but depends, for the proper completion of the rcycle and the performance of the intended operation, upon the receipt of a complete signal of preconcerted character. y i
Referring now to the drawings, the motor I vehicle (Fig. 1) is equipped with a signal transmitting mechanism including a sending antenna I which maybe mounted beneath the body 'of the vehicle in the manner disclosed in my prior Patent No. 1,792,193, dated February 10, 1931. In the driveway leading to the garage is a receiving antenna 5 leading to a signal 'responsive control mechanism within the garage and governing an electrically driven door operator shown diagrammatically at '6. I As shown at the left of Fig. 3, the sending an- ,tenna l is connected with an induction coil 1, whichin turn is in circuit with a car battery 8 and a` manually operable switch 9 on the instrument panel of the vehicle, the general arrangement being the same as shown inthe said Colman Patent No, 1,760,479, except for the use of the manually operable switchv 9 in place of a mechanically operated switch. Accordingly, in the present instance, the character of the signal transmitted is determined by the manner in which the switch 9 is operated by the driver of the vehicle;` It will be understood however, that instead of manual operation a simple mechanical operator under manual control may be employed. The power driven door operator, which may be of the type disclosed in the said Colman patent, in-
cludes ,a reversible electric motor I (shownat the right in Fig. 3) for actuating the door or doors as the case may be. Electric power is supplied to this motor under the control of a main switch Il interposed in one side l2 oi' a power line, of which I3 designates the other side.
The receiver for the transmitted signals forms perse no part of this invention, being substan- `tially the same as in said Colman patent. As shown, it comprises in addition to the receiving antenna a radio frequency coil I4 grounded at llli. i6 designates generally a vacuum detector tube'of the three element type, comprising a grid I1, a plate I8, and a filament i9.
' The filament is adapted to be heated continually from an alternating current line through a transformer 20 stepping down the voltage to approximately 6 volts. The alternating current as applied at 110 'volts to the plate or control circuit 2| is rectied by the detector tube and used to energize an electromagnetic control device. 'Ihe change in the output power upon the reception of a signal is suflicient to'operate such a control device. As shown, the plate circuit 2| has interposed therein a magnet 22 'having an 'armature 23 operating in response to the received signal.
24 is a grid condenser and 25 a variable condenser. The wave trains constituting the impulses of the transmitted signal, affect the grid in the well known manner, producing negative y the plate current flowing through the relay coil- 22 energizes the relay. On the other hand, when a signal is being received, a reduction in the plate current occurs, de-energizing the relay and permitting movement of the armature 23 by the spring 32.
In carrying out my invention, the operation of the relay under the control of the received signal is utilized first, to initiate the operation of a control device governing the actuation of the main motor swtich of the door operator, and then to insure continued operation of the control device through a complete cycle. To effectpproper operation of the relay to produce this result, the signal must be composed of units of different kinds, viz., impulse and space units, and these units must also occur in proper timed relation in the control cycle.
'I'he control device in the present instance comprises a shaft 33 having a series of cams thereon.
Y 'Ihis shaft is driven through the medium of a suitable gear train -34 by an electric motor having a rotary drive shaft. Preferably, I employ a small shadingring induction motor 35 having an energizing winding 36. Thus the driving means is of such character as to be operative upon continuous energization of the motor from` a local source of current as distinguished from an interrupted energization as in the case of ordinary stepping magnets directly responsive to a succession of transmitted impulses.
Energization of the motor 35 to start the cam shaft through an operating cycle is effected by the relay 22 under the control of the incoming signal. As herein shown, the cycle is initiated by the armature 23 and its spring 32 4as an incident to the reduction of the current in the plate circuit following the receipt of an initial impulse unit. In such movement, the armature 23 'closes a switch 31 the movable contact of which is carried by the pivoted armature support and is electrically connected by conductors 29 and 30 with a conductor 2|P forming part of the control circuit 2| and connected to the line conductor 21. 'Ihe stationary contact of this switch 31 is forme by an adjustable screw 38.
Said switch 31, hereinafter referred to as the primary relay switch, acts jointly with a switch 39 controlled by a cam 40 on the cam shaft 33 to energize the motor 35 and initiate the cycle. As shown, the cam 40 has a single lobe acting in the normal or rest position of the cam shaft to maintain the switch 39 closed. Of this switch` the stationary contact 4| is connected by a conductor 42 with the stationary contact 38 of the primary relay switch 31, and the movable contact 43 of the switch 39 is electrically connected to a conductor bar 44 from which a conductor 45 leads to the motor energizing winding 36. The opposite end of the winding 36 is connected by a conductor 46 to the line conductor 28. It will be seen that the switch 39 constitutes a starting switch for initiating the operation 'of the cam shaft 33 under the control of the primary relay switch 31 operating in response to an initial impulse unit of the received signal.
The cycle of operation of the present motor driven control device may be considered as being divided into two parts or movements, one initiated by the joint action of the switches 31 and 39, and a .second or final movement occurring as a continuation of the first movement provided the incoming signal is of a predetermined character. Accordingly, I provide means operating to cause the cam shaft 33 to revolve, when once started,
lthrough'one-half revolution, and then to interrupt such movement unless the interrupting means is renderedV ineffective by the receipt of a signal unit of a certain kind. In the latter event, the operation of the cam shaft is continued for the remainder of the cycle.
The means for insuring at least the first portion ofthe movement of the cam shaft comprises in the present instance, a cam 41 having two diametrically opposed notches 48 and controlling the operation of a switch 49 independently of the relay 22. The movable contact of this switch 49 is connected to the bar 44 electrically connected by the conductor 45 with one end of the motor winding 36, and the stationary contact of said switch 49 is connected by a conductor 50 and the conductors 3|] and 2| to the `line conductor 21. In the initial or rest position of the cam shaft, the switch 49 is open, but after the cam shaft is started by the joint action of the switches 31 and 39, the switch 49 is closed by the cam 41, so that the shaft 33 will revolve at least through one-half revolution or until the opposite notch 48 of the cam 41 permits the running switch 49 to open.
The ability of the switch 49 to interrupt the rotation of the cam shaft after the first movement thereof is dependent upon a variation in the transmitted signal and, in the present instance, upon the occurrence of a space unit controlling the operation of the relay 22 in advance of the opening of the switch'49. Such space unit is rendered effective through the conjoint operation of the relay and a third switch controlled by the cam shaft to continue the movement thereof through a complete cycle. Thus, I provide a secondary relay switch 52 arranged to be closed by the relay armature 23 in response to the receiptq of a space signal unit and an auxiliary running switch 53 in series with the switch 52 and arranged for actuation by a cam 54 on the cam shaft.
The movable contact of the auxiliary running switch 53 is electrically connected with the -motor as in the case of the switches 49 and 39, and the stationary contact thereof is connected by a conductor 53B with the stationary contact of the secondary relay switch 52, mounted on a suitable bracket 55. The relay armature carries the movable contact of the latter switch.
armature and close the relay switch 52. If, therefore, the auxiliary running switch 53 has at this time been closed, the circuit to the motor is completed. The cam 54 is,\of course, designed to hold the switch 53 closed long enough to maintain the motor energized until the control of the motor is restored to the main running switch 49, it being observed that the switch 49 is opened only momentarily at the end of one-halfV revolution of the cam shaft.
'The initiation of a door operating cycle is under the control of the timing device during the latter portion of its complete operating cycle, and such operation of the door operator is also made dependent upon the character of the received signal. To this end, I provide a switch 51 arranged to be closed by a cam 58 `on thesliaft 33 near the end of the complete control cycle. This switch 51 operates in conjunction with the primary relay switch 31 to control the energizaton of a magnet S arranged to close the main motor switch ii in any suitable way as, for example, that shown in the said Colman patent! Said magnet 59 may be energized from the door operator circuit which is connected with the main supply line i3 through the medium of the reversing switch of the operator 6 and the normally closed field switch of the motor Ill, the other end of the magnet coil being connected by a conductor 60 with the movable contact of the switch 51. The stationary contact of this latter switch is connected by a conductor 6l to the stationary contact 38 of the primary relay switch 31, so that when the latter.switch is closed, the above described circuit for relay 59 is extended by way of conductors 29, 3D, 2ia and 21 to conductor I2 of the power line. Accordingly, operation of the main motor control switch Il is dependent upon the simultaneous closure oi the primary relay switch 31 and the cam-actuated switch 51, the
erator, actuatethe transmitter. switch 9, first to close the same, then to open the same, and nally to close the switch, the opening and final closing operations of the switch 9 to be performed in timed relation to the operation of the main running switch 49 by its cam 41 and to the operation of the door control switch 51 by its cam 58, as
will be hereinafter more particularly set forth, in`
connection with the time chart (Fig. 2).
In the preferred embodiment, a special-mechanically actuated grid discharge device is employed in connection with the radio receiver circuit for the purpose of conditioning the detector tube and the relay controlled thereby, so as to insure proper operation of the relay armature 23 in response to the received signal units. This discharge device comprises a switch 62 arranged for actuation by a cani 63 on the shaft` 33 and having a stationary contact connected by conductors 63 and 63' with the grounded side of the tube filament i9, and a movable contact con-l nected by conductors 65 and 65a with the grid.' The cam 63 has two diametrically opposed lobes 'operable to close the switch 62 and thereby permit discharge of the grid rst, after the receipt of the first signal unit, and again after the receipt of the third signal unit.' In the ilrst 1nstance, such discharge of the grid insures prompt 7restoration of the plate current inthe relay conthe control cycle, operates to condition the tube for the reception of the first-impulse unit of the next signal, so that immediately upon the termination of one signal, another Vsignal may, if desired, be transmitted and received.
`The'use of a mechanically operating grid discharge device is preferred for the reason that it effects a rapid restoration of the detectortube after each impulse unit is received. If desired, however, an ordinary grid leak may be used in addition to such a mechanical device, and I have shown in broken lines in Fig. 3 a grid leak 69 connected in an ordinary way. If such a grid leak is used, the length or duration of the first signal impulse is not important. Thus itis only necessary that the first impulse unit be interrupted so that a space unit will occur and thus permit of closure of the secondary relay switch 52 for cooperation with the auxiliary running switch 53 to complete the cycle, and that a second .impulse unit occur to eiect a closure of the primary relay switch 31 in proper'timed relation to the door control `switch 51. Thus, in this instance, a greater latitude is allowed the operator to effect thel desired control.
Referring now to the time chart (Fig. 2), the operation will be summarized and the sequence which permits of the actuation of the armature' 23 by its spring 32. The primary relay switch 31 is thus closed, and this switch acting jointly with the closed starting switch 39 initiates a.y control cycle. In the present instance a complete control cycle is one complete revolution of the cam shaft. Shortly after such initiation of the control cycle, the main running switch 49 is closed by its cam 41 as indicated at a in the `time chart,
and as soon as this switch k49 has been closed, the starting switch 39 is opened as indicated at b. Thus, the control device is started through its rst half cycle. under the control of the first or impulse unit of the signal.
\ particularly set forth in connection with the pre-v The continuation of the control device through the second portion of its cycle requires the terterminated well in advance of the closure of the auxiliary running switch 53 at d, as for example at e, corresponding in time to the closing of the grid discharge switch 62 lat point f through the operation of a cam 63. In any event the first impulse must be terminated somewhat in advance of the point g, when the grid discharge switch opens, to insure that the latter switch shall be held closed long enough -to effect a complete discharge of the grid of the tube i6.
Upon such discharge of the grid the plate current in the control circuit is promptly restored, so that the relay 22 becomes energized to effect closure of the secondary relay switch 52, while the auxiliary running switch 53 is closed at d for cooperation with the switch 52 in continuing the energization of the motor` Consequently,the subsequent opening of the main running switch at c is ineffective to stop the control motor so as to interrupt the cycle at the end of its first movement. The auxiliary running switch 53 remains closed until point h suiiiciently subsequent to the closure of the main running switch 49 at point i to insure transfer of control from one switch to the other. On the other hand it will be understood that if an impulse unit should be received at any point subsequent to the point g and in advance of the point i, the secondary relay switch will be prevented from closing and therefore the driving motor will be stopped in an intermediate position.
Assuming that a complete cycle of the control device has been assured, energlzation of the main motor switch Il to initiate operation of the door' operator, is still dependent upon the proper transmission of an impulse unit constituting the third unit of the signal. The grid or tube having been discharged as above set forth, this third or impulse unit must be received in proper timed relation to the actuation of the door control switch 51 by its cam 58. As shown, such closure of the door control switch 51 occurs at point j as shown in the time chart, and in order that the relay switch 31 will have been closed in advance of the closure of said switch 51, the third signal unit, while indicated on the chart as commencing substantially at k, must be received between thel points i and l. If received before point i, it will prevent closure of the secondary relay switch 52; and if received subsequent to point l,r the door control switch will have opened. As shown on the chart, the door control switch 51 remains closed for a short time, between points j and ld; and th`e third signal unit is shown as terminating at 1n, although it may be continued somewhat beyond this point as will presently appear.
To condition the tube for the immediate reception of the first impulse unit of a succeeding signal, should that be desirable, the grid discharge switch 62 is again closed at n. and again opened at o just in advance of the termination of the cycle. Similarly, the starting switch 39 is closed at p and the main running switch 49 opened at q preparatory for the next cycle.
ya properv control cycle requires that the operator send first, an impulse unitterminating before point a; second, a space unit between points g andi; and third an impulse unit between points i and l.l Moreover, the third vunit must be terminated in advance of the point o to avoid initiation of another control cycle.
It will be observed that by the arrangement thus set forth, the operator of the vehicle may by a proper timing of the operation of the manual transmitting switch 9, initiate from a remote point the operation of the power driven 4door operator, it merely being necessary that the operator cause the switch 9 to'be open for the transmission of a space signal unit in proper timed relation to the mechanical operation of the main and auxiliary running switches. Exact timing is, however, not necessary, and the operation of the control device at true synchronous speed is also not required. In other words, the method of control employed is sufciently flexible to permit Aof slight variation in timing, both in so far as the human element is concerned and also, with regard to the mechanical operation. Should the operator fail to open the switch 9 within the time allotted, the operating cycle will be interrupted at the end of the first movement through the operation of the main running switch 49. In this event, the
' means for continuing the cycle, namely, the
auxiliary running switch 53 and the secondary relay switch 52, will be rendered ineffective because of the failure of the relay 22 to close the switch 52. Similarly, in the event of initiation of the cycle by a single electric impulse, such as may occur in a thunder storm, the cycle will be interrupted at the end of the first movement.
a first or impulse unit be terminated properly Y so as to effect a completion of the control cycle, initiation of the door operating cycle is still dependent upon the transmission of an impulse to constitute the third unit of the signal; and that this impulse must be transmitted so as to occur in timed relation to the closure of the door co'ntrol switch 51 by the cam 58. Therefore, the transmission of a short impulse constituting the ,first unit of the signal followed by a space unit continued throughout the remainder of the cycle, would be ineffective to initiate a door operation.
In the event that a grid leak 66 is used in adldition to the mechanical grid discharge, the first impulse unit of the signal maybe continued, as for example to point r, reference being made to the time chart in which this modified signal is shown in broken lines. Thereafter, the occurrence of a short space unit in the signal will permit the continuation of the operating cycle througha closure of the secondary control switch 52. Finally, transmission of a third unit in the form of an impulse occurring while the door control switch 51 is closed, will initiate the operation of the door motor. It will be seen, however, that greater care is necessary to be exercised on the part of the operator where a mechanical `grid discharge is used, and therefore, it is possible with this latter construction to obaoeaseo tain a higher degree of secrecy so as tdlesser the possibility of unintended or accidental operation.
AI claim as my invention:
-1. A control mechanism having a signal rsponsive receiver, a partto be operated, a primary control lmeans differentially operable in response to a received signal having units of diiferent -kix/ids, and a cyclically operable secondary `control means cooperating with the primary control means only upon the receipt of a preconcerted signal combination to initiate the operation of said part, vsaid secondary control means including an electric motor having a control circuit, a plurality of switches actuated by said motor and cooperating with said primary con trol means at different points in,y the operating cycle of the secondary control means to maintain said control circuit closed duringa predetermined operating cycle, and -an additional switch actuated by said motor and cooperating with said primary control means at a point in said operating cycle subsequent to said first mentioned points to initiate the operation oi saidv ing cycle and subsequently in response lto va different kind of signal unit to complete said operating cycle, and means actuated at a predetermined point in the cycle subsequent to the receipt of said diierent signal unit to `cooperate with said signal responsive means in .initiating the operation of said part. u
3. remote control system having in combination with a part to be controlled, means for transmitting a signal composed of impulse and space units, a control device to be operated through a predetermined cycle, driving means for said device including a rotary electric motor, and means responsive to a transmitted signal of a preconcerted character adapted to cooperate with said control device to control the energization of said motor`,'saidsignal responsive means being operative during an intermediate portion of the cycle only under the control of a space unit to maintain said motor energized, and said control device having means cooperating with said signal responsive means in response to a'signal unit'of a predetermined character occurring subsequent to the movement of said device past said predetermined point to vgovern operation of said part to be controlled. A
fi. A remote control system having in combination with a part to be controlled, means for transmitting a signal combination composed of :units of different kinds, a control device to be operated through a predetermined cycle, driving means for said device including a rotary electric motor, and
, means responsive to a transmitted signal of a preconcerted character and adapted to cooperate with said control device to effectmovement of said `device through said cycle,y said signal resp'onsive means being operative under the control of a signal unit oifa predetermined character only to maintain said motor energized at an intermediate point in the cycle; and said. conltrol device andrsignal responsive means being further operative under the control of a signal unit of a predetermined character occurring subsequently to the movement ofv said device past said predetermined point to govern the operation of said part to be controlled.
5. A remote control system for effecting a control operation in response to a particular signal, said system having, in combination, means for transmitting a signal composed of units of different kinds occurring in succession, a control device to be operated throughl a predetermined cycle, driving means for said device including an electric motor, and means responsive to a .transmitted signalof a lpreconcerted character adapted tol cooperate with said control device to effect movement thereof through said cycle,
said control devicevincluding two motor control switches and a third switch, and said Isignal responsive means being adapted to cooperate with said two motor control switches at different times in response to signal units of different kinds to govern the energization of said motor, and to cooperate With'said third switch in response to a signal unit received subsequent to the signal units governing the energization ofthe motor to eiiecta control operation.
6. A remote control system having, in combination with a part to be controlled, `means for transmitting 'a signal composed of units of different kinds, atcontrol device to be operated through a predetermined cycle, driving means for said device including a rotary electric motor, and means responsive to one unit of a transmitted signal of a preconcerted character adapted to cooperate with said control device to initiate movement thereof through a part of said cycle and responsive to' another unit 'of said signal to initiate movement of the device through the remainder of said cycle, said control device including means operative in conjunction with said signal responsive means in the latter part of the cycle to govern the operation of said part to be controlled.
7. A remote' control system for effecting the operation of a motor driven operator, said system having a motor driven control means, including an electric motor and a control `element vto be driven thereby through a predetermined cycle, means for initiating the energization of said motor from a normal rest position including a signal responsive device responsive to one kind oi signal unit, other means operable by said control element in the initial portion of its movement to continue the energization of said`motor through a predetermined distance and then to interrupt such energization, means including a second signal responsive device responsive to a .different kind of signal unit to render the'last mentioned means ineffective to interrupt the energization of said motor, and means actuated by .said control element in the latter part of its cycle 'operative in cooperation with said first signal responsive device for initiating the operation of said power driven operator.
8. A remote control system having, in combination, a control device to be operated through a predetermined cycle, means responsive to a signal composed of impulse and space vunits including a control circuit having an electromagnet therein and a detector tube having a grid tending to retain the-characteroi .an impulse unit of the received signal, said signal responsive means being arranged to cooperate with said control device in response to signal units of diierent kinds to effect movement of the device through said cycle, and means operative after the receipt of an impulse unit to discharge the grid of said tube and to condition the magnet for operation only under the control of a space unit following the impulse unit within a predetermined interval.
9. A remote control system having, in combination, a control device to be operated through a predetermined cycle, means responsive to a signal composed of impulse and space units including a controlling circuit having an electromagnet therein and a detector tube having a grid tending to retain the character of an impulse unit of the received signal, means for driving said control device including an electric motor, switch means for controlling the energization 0f said motor during said cycle including a pair of switches controlled by said magnet in response to an impulse unit and a succeeding space unit, respectively, and a pair of switches controlled by said device cooperating successively with said first mentioned switches and operative respectively to initiate and maintain energization of said motor; and means for discharging the grid of said tube after the receipt of the impulse unit to condition the magnet for operation only under `the control of the succeeding space unit received within a predetermined interval after said impulse unit.
10. A remote control system having a. control mechanism including an electric motor having a rotary armature, a control device having a xed driving connection with said armature and adapted to be driven in one direction only from the beginning of one control cycle to the normal starting position of the next control cycle, a part to be operated, and signal responsive means cooperating with said device at different points in said cycle to control energization oi said motor and at a point in sai'd cycle subsequent to said rst mentioned points for initiating the operation of said part to be controlled.
' DUNCAN J. STEWART.