US3891900A

US3891900A - Control system for vehicle gates

Info

Publication number: US3891900A
Application number: US422853A
Authority: US
Inventors: Terry B Gallant
Original assignee: AUTOMATION GENERAL
Current assignee: AUTOMATION GENERAL
Priority date: 1973-12-07
Filing date: 1973-12-07
Publication date: 1975-06-24
Anticipated expiration: 1992-06-24

Abstract

A control system that operates a vehicle gate with a single control input required to obtain open, close and reopen modes of operation. The primary control over the gate closing is by a close timer which is set by the gate tripping an open limit switch. The operation of the gate closing relay is inhibited by a safety circuit when sensors detect the presence of the vehicle within the area of the gate operation. The sequencing of operations is paced by a reversing timer which also serves to insure that a full charge is placed on the timing capacitor in the close timer during each cycle of operation.

Description

United States Patent 1191 Gallant 5] June 24, 1975 [54] CONTROL SYSTEM FOR VEHICLE GATES $366,855 l/l968 Huber ct til 3i8/l6 3, 3 41972 H d v1. ..3l8267 [75] Inventor: Terry B. Gallant, San Diego. Calif. 654 5 5 I an W e d [73] Assignee: Automation General, San Diego, Primary ExaminerL. T. Hix

Calif. Attorney, Agent, or FirmBrown & Martin [22] Filed: Dec. 7, 1973 [21] Appl. No.: 422,853 [57] ABSTRACT A control system that operates a vehicle gate with a single control input required to obtain open, close and [52] US. Cl 317/139; 3 [7/14] S reopen modes f operation The primary C0mm| [5 I] Int. Cl. Hlllh 47/14 the gate Closing is by a close timer which is set by the [58] Fleld of Search 317/139 141 S; gate tripping an open limit switch. The operation of 3l8/267- 16; 387/149 the gate closing relay is inhibited by a safety circuit when sensors detect the presence of the vehicle within [56] Reierences cued the area of the gate operation. The sequencing of op- UNITED STATES PATENTS erations is paced by a reversing timer which also 2,425,312 8/1947 Gower 3l8/267 serves to insure that a full Charge is Placed on the 2.895,728 7/l959 Edelman 318/267 ing capacitor in the close timer during each cycle of 2,9|3,65l 1 H1959 Smith et al 3l8/267 operation. 3,l8l,049 4/!965 Klamp 318/267 3,204,169 8/1965 Ranson 3l8/267 11 Chums, 3 Drawlng Figures RECEIVER CONTROL SYSTEM PATENTEDJUN24 I975 SHEET RECEIVER CONTROL SYSTE M Fig. I

D O--O Fig. 2

CONTROL SYSTEM FOR VEHICLE GATES BACKGROUND OF THE INVENTION The large number of vehicles and particularly automobiles that are currently in operation, combined with the need to provide security against unauthorized activity, and the high cost of labor, have combined to produce a large demand for automatic vehicular gates. Such gates are employed in apartment buildings to limit access to the parking space within the building, in parking lots to require the taking of a time stamped ticket before admission to the lot, in parking lots to require the payment of a pre-determined sum before the vehicle is permitted to exit from the lot, and in a wide variety of similar applications. Depending upon the pecularities of the particular installation and on the drive system selected, any one of several different type of gates may be employed such as, single swinging gates, opposed swinging gates, vertical roll-up gates, single hung pivoting gates, and vertical to horizontal tracked gates.

Another major area of variations between particular installations is in the sensors employed. Sensor types include magnetic loops, pressure switches, and various electric eye types. These sensors are combined with remote actuation devices that range from switches and card keys, to radio controlled devices.

All of the motor powered gates of the prior art have required a control system of one kind or another. Prior art control systems have typically been designed for a particular type of installation; such as a control system designed for radio controlled actuation or a system designed for a vehicle exit gate which is tripped by a magnetic loop sensor. Typically, control systems for one type of gate are not easily adaptable to other installations. Further, these control systems are not easily adaptable to adding functions or for custom installations. This results in the production volume for any one control system to be relatively lower than it might otherwise be, with the resulting high unit production cost. For those installations which require a custom control system design there is little opportunity to de-bug the circuit to insure that all possible operational contingencies have been explored and the necessary functions provided.

Thus it is desirable to have a control system for vehicle gates that is adaptable to a wide variety of vehicle gate installations and which is relatively low in cost while maintaining a high degree of operational reliabil ity.

SUMMARY OF THE INVENTION An exemplary embodiment of the invention will be described in association with a specific vehicle gate installation. Whereas, the invention is particularly adaptable to vehicular gates, it is to be understood that the terms gate and vehicle gate as used herein are intended to include any power-driven device controlled by remote actuation devices through a range of travel as determined by a plurality of limit switches. Thus, the system is applicable to an installation where pedestrian doors are activated by the detection of an individual approaching the door, or as an extreme example, is applicable to a system for raising and lowering a flag in response to remote radio control actuation.

The system incorporates a single signal control input means which translates the closing of a switch, such as may be produced by manual or remote operation, into a pulse that momentarily closes a solid state switch and energizes an isolation relay. The energized position of the isolation relay contacts closes the gate open relay. Power to the isolation relay and therefore actuation power to the gate open relay which would otherwise be interrupted by energization of the open gate relay is maintained for a sufficient duration to insure open gate relay contact closing by a capacitive delay. The gate open relay latches closed and is not disturbed by subsequent actuations of the single signal control input. In the relaxed state the contacts of the isolation relay provide primary power to charge the capacitor in a close timer. The reverse timer insures that there is sufficient time in the gate close timer charging cycle to fully charge the gate close timer capacitor. This is accomplished because the reverse timer carries a charge which must be dissipated before the isolation relay is sequenced away from providing charging power. When the gate has reached the extreme of its normal travel, it trips an open limit switch which opens the energization coil circuit, causing the gate open relay to relax. In its relaxed state the gate open relay enables the energization circuit of the close gate relay. Gate closing cannot commence until the gate close timer times out or a manual close gate switch is activated and the safety circuit is not preventing its operation.

The timer employs a J-type field effect transistor (FET) with a very low power drain which makes it possible to obtain long duration timing cycles through the adjustment of a bleed resistor. Thus the accurate, consistent, charging of the timing capacitor is important and the system assures this regular charging by a well regulated primary power supply and by insuring that the charging cycle is always of sufficient duration to provide a full charge. A diode in the capacitor to ground circuit prevents the capacitor from discharging in that path and therefore the full potential is presented to the base of the PET. When the bleed resistors reduce the potential sufficiently the FET turns off and this indirectly produces the closing of a switch that completes the energization circuit activated by the relaxation of the gate open relay and therefore the activation of the gate close motor. A safety circuit can prevent gate closing by drawing down the primary power if they are switched to indicate an obstruction in the range of gate travel. Such an obstruction might be the presence of a vehicle within the swing range of the gate, which would be detected by a magnetic loop and would prevent the activation of the close cycle. An alternative contact provides an inhibit circuit so that once the gate closing operation has commenced the safety switch will not cause cycle stoppage.

With the gate in the closing mode it is possible to cause a reopening of the gate by activation of the single signal control input. This causes an immediate relaxation of the close gate relay through the safety circuit whereas the reversal timer prevents reactivation of the open relay until a predetermined time delay has elapsed thereby preventing excessive mechanical loads occasioned by an instantaneous reversal.

It is therefore an object of the invention to provide a new and improved control system for vehicle gates.

It is another object of the invention to provide a new and improved control system for vehicle gates which is adaptable to a wide variety of installations.

It is another object of the invention to provide a new and improved control system for vehicle gates which provides for multiple functions with a single input.

It is another object of the invention to provide a new and improved control system for vehicle gates which isolates the input from the operating portions of the circuit.

It is another object of the invention to provide a new and improved control system for vehicle gates which is adaptable to vehicle operated and operator operated control.

It is another object of the invention to provide a new and improved control system for vehicle gates with highly reliable and consistent operation.

It is another object of the invention to provide a new and improved control system for vehicle gates that guards against undesirable and dangerous operation.

Other objects and many attendant advantages of the invention will become more apparent upon a reading of the following detailed description, together with the drawing in which like reference numerals refer to like parts throughout, and in which:

FIG. 1 is a diagram of a typical installation of the system.

FIG. 2 is a side elevation view illustrating vehicle progression over the sensors.

FIG. 3 is a wiring diagram of the control system.

Referring now to the schematic wiring diagram of FIG. 3, there is illustrated a single signal control input means 12. Any device which connects between the terminals l4 and [6 such as a manually operated switch, magnetic loop, or radio receiver output. applies primary B+ power through the resistor 18 and through the

capacitors

20 and 22. The capacitor 20 acts as a pulse generator in association with the

resistors

24 and 26. Thus when the connection between the

terminals

14 and 16 is made, a single pulse, generated by the charging of the capacitor 20 is applied to the base of transistor 28. Transistor 28 begins conducting along the path through the diode 30, and transistor 32. Transistor 32 is maintained in a conducting state, as will be described more fully hereinafter. Thus B+ power is drawn through the energization coil of isolation relay 34 through the

transistors

32 and 28 and diode 31 and to ground through a normally closed limit switch (open limit) bridging the

contacts

4 and 5. The limit switch is open only when the gate reaches its open extreme of travel. The signal on the

contacts

14 and 16 is also transmitted through the resistor 36 and diode 38 to charge the capacitor 40. Capacitor 40 association with resistor 42 forms a reverse timer 44. When the capacitor 40 is charged it holds the transistor 46 on, thereby providing a conductive path for the charge on capacitor 48 through resistor 50 and transistor 46 to ground. Since a charge is maintained on capacitor 48 in the relaxed state of gate open relay 52 there is voltage applied to the base of transistor 32 through

resistors

50 and 54. This holds the transistor 32 in a conducting state for a sufficient period that the isolation relay 34, through its contacts 58, will energize and complete the closing of the gate open relay 52 on line 60. It will be noted that the energization circuit of the gate open relay 52 includes closed contacts of the gate close relay 64. The contacts 66 are closed only in the relaxed state, completing a conductive path on line 67 to the nor mally closed limit switch between

terminals

4 and 5. Thus both gate relays cannot be closed at the same time. Since the de-energization of the gate close relay 64 removes charging power from the capacitor its energy will eventually (on the order of one second) be dissipated to ground through the transistor 46. This insures a full charge on capacitor 70. Thus the transistor 46 base bias is eliminated and the transistor ceases conduction. This permits encrgization of the isolation relay 34 by B+ power from the relay 52 through the resistors and 54. Energization of the relay 34 removes B+ charging power on line 68 from the capacitor 70 of the gate close timer 71.

Since the resistor 76 is relatively low valued the subcircuiting including capacitor 70 and resistor 76 functions substantially as if the positive side of the capacitor 70 was connected to ground. Thus diode 74 and resistor 80 see a relatively negative potential. This negative potential is blocked by the diode 75 and is led to ground through the resistors and 82.

The next time that the isolation relay 34 is energized, the operation of the timer is commenced. The diode 74 blocks the path to ground, and therefore the positive side of the capacitor 70 looks at ground through the relatively low resistance (compared to resistors 80 or 82) resistor 76. The discharging voltage of capacitor 70 is applied to the base of the field effect transistor (FET) 84 through resistor 86. This maintains the FET 84 open. The open FET 84 releases the current flowing through resistor 95 allowing it to flow through inverter 94. Inverter 94 draws current from the safety means through jumper 92 and resistor 95 to ground, holding inverter closed. Thus the sequencing of the contacts 58 does not initially change the status of the timer circuit, and conduction continues through inverting amplifier 94, maintaining the secondary inverting amplifier in a non-conducting condition by drawing the B+ power through resistor 104 to ground. When the capacitor 70 is discharged sufficiently the FET 84 begins to conduct, terminating conduction through inverter 94, and thereby making B-lpower available through resistors 106 and 108, and delivering voltage to the base of the inverting amplifier 100. When inverting amplifier 100 begins conducting the resultant flow through resistors 111 and 114 applies a voltage to the base of transistor 112 which begins conducting and thereby closes the energization circuit for the gate close relay 64. Thus the timer provides an interval before gate closure that may be selected to be a sufficient period for a vehicle to pass through the gate. After the timing out of the timer the closing action will commence unless it is prevented by the safety circuit 90.

The safety circuit 90 provides the multiple functions of preventing gate action when external sensors detect the presence of a vehicle in the path of the gate, or other undesirable circumstances, operates to recharge and reset the timer, and adds the additional function to the single signal control of controlling gate reopening, in addition to the initial opening. These functions will be described more fully hereinafter. B+ power through resistor and 122 maintains the transistor 124 in conduction thereby permitting B+ power to be delivered to the gate close switch 112 on line 126. The train sistor 124 terminates conduction by drawing down the 13+ power whenever the tenninal 128 is grounded ei- 5 ther through the

terminals

130 or 132. Terminal 132 is loop. Terminal 130 is utilized as an inhibit means to prevent the safety action unless the gate close relay 64 is in the relaxed position illustrated. In the relaxed position B+ power through the contacts 66 and resistor 140 maintains the transistor 142 in conduction. However, as soon as the relay 64 is energized and the contacts moved out of their relaxed position, the transistor 142 ceases conduction and inhibits the safety action.

An additional function for the single signal control input 12 is provided whenever the jumper 91 is installed. A signal from the transistor 28 through resistor 41 and jumper 91 has the effect of bypassing the close timer 71 and initiate gate closing action.

The safety circuit acts to increase the functions of the single signal control input by drawing down the B+ power through line 150 and diode 152 when the input is pulsed, causing conduction through transistor 28. This effectively withholds base bias from the transistor 124 and prevents the delivery of B+ power to the gate close relay 64 through the transistor 112 or from the

terminals

180 and 182. Thus if the system were in the gate close cycle, the closing action would be terminated. At the same time the isolation relay 34 would close and commence an open cycle after the timing out of the reverse timer 44.

A final function of the safety circuit is to charge the close timer after each safety circuit operation. A transistor 160 is held in a normally on condition by a voltage

divider comprising resistors

162 and 164. When it is conducting, B+ power through the contacts 66, is delivered through a resistor 168 to ground. When the transistor 160 opens due to the drawing down of its base biasing B+ by the operation of the safety circuit, the B+ through the resistor 168 is delivered through resistor 170 and to charge capacitor 40. The resulting voltage closes transistor 46 and thereby opens transistor 32 which relaxes relay 34 and causes the contacts 58 to move to the open, timer-charging position. The reverse timer 44 insures that a full charge will be delivered to the close timer as described hereinbefore.

It will be noted that

contacts

180 and 182 are provided which may be utilized as a separate close gate switch, substituting for or supplementing the timer action.

Referring now to FIGS. 1 and 2, there is illustrated an exemplary application of an operating environment in which the control system of the invention may be utilized. A gate 200 is utilized to control traffic through a door opening between

walls

202 and 204 along a roadway 206. A gate open sensing loop 208 is provided on the opposite side of the gate. When a vehicle 212 approaches the loop 208 a contact is closed between the

terminals

14 and 16 which initiates the gate opening action by delivering power through the switch of gate open relay 52. The vehicle can then proceed through the now open gate and across the safety sensor 210. The safety sensor may be applied across the

terminals

128 and 130, for example, and will prevent the operation of the gate close relay 64 even should the vehicle stop on the safety sensor 210 for an extended period of time. However, once the vehicle moves beyond the sensor 210 the gate closing action is initiated, any safety circuit activity on loop 210 is inhibited by the transistor 142 so that a steel gate may be utilized and not trip the safety circuit. If the control system and gate are to be utilized solely in the manner of an exit gate as described, then the jumper 91 would be removed from the circuit so that inputs to the single signal control could only cause gate opening or reopening.

If the system is to be utilized as a portion of a radio remote control gate operator. the receiver 102 will be substituted for the loop 208. The jumper 91 would be left in the circuit a signals from the receiver 102 would connect the

terminals

14 and 16. With the gate closed. a pulse on the terminal 14 and 16 would result in initiation of gate opening action. A second pulse when the gate was in the opening condition would be ignored by the system, but the gate can be commanded to close as soon as opening is completed by a third pulse. Similarly, if it is desired to terminate the closing action and cause the gate to reopen. then a fourth pulse would draw down the B+ through the safety circuit and relax the close relay 64 immediately. After the reversing timer 44 times out the gate opening action would commence.

Having described my invention, I now claim:

1. A control system for motor driven gates comprising:

a gate close timer,

a gate open relay,

a gate close relay,

a single signal control input means for selectively closing and latching said gate open relay, and charging said gate close timer,

open limit switch responsive means for unlatching said gate open relay and for starting the cycle of said timer,

timer responsive means for closing and latching said gate close relay.

2. A control system according to claim 1 including:

gate reverse timer means for producing a delay in the activation of said gate open relay and for maintaining a minimum charge duration for said charging of said gate close timer.

3. A control system according to claim 1 wherein:

said single signal control input means is responsive to a unitary control pulse.

4. A control system according to claim 1, including:

discriminator means for selectively accepting a pulse from said single signal control input means as a command that closes said gate open relay, that opens said gate close relay and closes said gate open relay, or that closes said gate close relay.

5. A control system according to claim 1 including:

safety means for withholding power from said gate close relay when a signal is present on said safety means.

6. A control system according to claim 5 including:

inhibit means for selectively preventing said safety means from operating after said gate close relay has closed.

7. A control system according to claim 1 wherein:

said close timer means comprises a capacitor biased field effect transistor.

8. A control system according to claim 1 wherein:

the signal charging said close timer also holds closed an inverting amplifier,

said field effect transistor allows said inverting amplifier to remain closed until the charge on said eapacitor has been bled down to a predetermined level.

9. A control system according to claim 5 wherein:

said safety means comprises an emitter-follower that withholds primary power from said gate close relay 7 8 when the input of said emitter-follower is drawn to ducting for a sufficient period to latch said gate ground. open relay closed. 10. A control system according to claim I wherein: H. A control system according to claim 10 further said single signal control input means includes an isoincluding:

lation relay having a solid state switch in the energi- 5 a reversing timer comprising a capacitor, zation winding circuit, the charge on said reversing timer preventing the cysaid solid state switch is hold on by a signal from at cacling of said isolation relay for a period sufficent to pacitor comprising a delay means, permit said close timer to become fully charged. said capacitor holding said solid state switch con-

Claims

1. A control system for motor driven gates comprising: a gate close timer, a gate open relay, a gate close relay, a single signal control input means for selectively closing and latching said gate open relaY, and charging said gate close timer, open limit switch responsive means for unlatching said gate open relay and for starting the cycle of said timer, timer responsive means for closing and latching said gate close relay.

2. A control system according to claim 1 including: gate reverse timer means for producing a delay in the activation of said gate open relay and for maintaining a minimum charge duration for said charging of said gate close timer.

3. A control system according to claim 1 wherein: said single signal control input means is responsive to a unitary control pulse.

4. A control system according to claim 1, including: discriminator means for selectively accepting a pulse from said single signal control input means as a command that closes said gate open relay, that opens said gate close relay and closes said gate open relay, or that closes said gate close relay.

5. A control system according to claim 1 including: safety means for withholding power from said gate close relay when a signal is present on said safety means.

6. A control system according to claim 5 including: inhibit means for selectively preventing said safety means from operating after said gate close relay has closed.

7. A control system according to claim 1 wherein: said close timer means comprises a capacitor biased field effect transistor.

8. A control system according to claim 1 wherein: the signal charging said close timer also holds closed an inverting amplifier, said field effect transistor allows said inverting amplifier to remain closed until the charge on said capacitor has been bled down to a predetermined level.

9. A control system according to claim 5 wherein: said safety means comprises an emitter-follower that withholds primary power from said gate close relay when the input of said emitter-follower is drawn to ground.

10. A control system according to claim 1 wherein: said single signal control input means includes an isolation relay having a solid state switch in the energization winding circuit, said solid state switch is hold on by a signal from a capacitor comprising a delay means, said capacitor holding said solid state switch conducting for a sufficient period to latch said gate open relay closed.

11. A control system according to claim 10 further including: a reversing timer comprising a capacitor, the charge on said reversing timer preventing the cycling of said isolation relay for a period sufficent to permit said close timer to become fully charged.