Electronic vehicle door lock/unlatch control

• US 4,858,971 A
• Filed: 03/07/1988
• Issued: 08/22/1989
• Est. Priority Date: 03/07/1988
• Status: Expired due to Term

• Current Assignee: Inteva Products LLC (Renco Group Incorporated)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Manuel, Mark, Haag, Ronald H., Rogers, Lloyd W.
• Primary Examiner(s): Moore, Richard E.
• Application Number:
  US07/164,903
• Time in Patent Office: 533 Days
• Field of Search: 292/336.3, 292/201, 292/144, 292/292, 292/DIG. 43, 292/46, 70/238, 70/264
• US Class Current: 292/201
• CPC Class Codes: E05B 77/48 by electrical means
• CPC Class Codes: Y10T 292/0851 Cam and lever
• CPC Class Codes: Y10T 292/1082 Motor
• CPC Class Codes: Y10T 292/57 Operators with knobs or handles

Abstract

An electronic door lock/unlatch control in which the latching mechanisms latch mechanically upon door closing and include electric motor driven unlatching mechanisms but no mechanical locking apparatus. Locking is accomplished electronically for each door by a flip-flop which enables or disables a power MOSFET connected in series with the unlatch motor and unlatch switch for the door and an electric power source. The flip-flop for each door also controls lock status indicating lights. A rear door unlatch disable switch is included additionally in series with the rear door unlatch switch to allow operator disabling of the rear doors.

Claims

1. An electronic door lock/unlatch control for a motor vehicle having an electric power source, an ignition switch connected to the electric power source and at least one front door and one rear door, each of the front and rear doors having a mechanical latch mechanism adapted to latch the door automatically upon door closure and having a mechanical unlatch mechanism driven by an electric motor, when activated, to unlatch and partially open the door, the control comprising, in combination:

a front door unlatch switch;

a first transistor connected in series with the front door unlatch switch and electric motor of the front unlatch mechanism across the electric power source, the first transistor having a control electrode;

a first bistable device having an output connected to the control electrode of the first transistor and being characterised by a first state effective to enable conduction of the first transistor upon closure of the front door unlatch switch and a second state in which conduction of the first transistor is prevented;

a front door unlatch switch;

a rear door unlatch switch;

a second transistor connected in series with the rear door unlatch switch and the electric motor of the rear unlatch mechanism across the electric power source, the second transistor having a control electrode;

a second bistable device having an output connected to the control electrode of the second transistor and being characterised by a first state effective to enable conduction of the second transistor upon closure of the rear door unlatch switch and a second state in which conduction of the second transistor is prevented;

a front lock switch connected to the electric power source and the first and second bistable devices and effective, when closed, to put the first and second bistable devices in their second states to disable unlatching of the front and rear doors;

a front unlock switch connected to the electric power source and the first and second bistable devices and effective, when closed, to put the first and second bistable devices in their first states to enable unlatching of the front and rear doors;

a rear lock switch connected to the electric power source and the second bistable device and effective, when closed, to put the second bistable device in its second state to disable unlatching of the rear door;

a rear unlock switch connected to the electric power source and the second bistable device and effective, when closed, to put the second bistable device in its first state to enable unlatching of the rear door;

a rear unlatch disable switch connected in series with the second transistor, rear door unlatch switch and the electric motor of the rear unlatch mechanism across the electric power source, the rear unlatch disable switch being located within reach of a vehicle operator but out of reach of a passenger using the rear door and effective, when open, to prevent unlatching of the rear door;

front lock and unlock indicating lights associated with the front door;

rear lock and unlock indicating lights associated with the rear door;

an indicating light drive circuit for each of the front lock, front unlock, rear lock and rear unlock indicating lights responsive to an enabling input and the output of the bistable device controlling enablement of the unlatching mechanism of the associated door to indicate the lock/unlock status thereof;

a timing circuit effective to supply the enabling signal to the indicating light drive circuits while provided with an activating voltage input and for a predetermined time after removal of the activating voltage input;

a door jamb switch connected to the electric power source and activated while the front door is open to provide the activating voltage to the timing circuit; and

circuit means connected to the electric power source through the ignition switch to provide the activating voltage to the timing circuit, whereby the lock/unlock status of the locks is displayed while the ignition switch is closed, while the front door is open and for at least the predetermined time thereafter.

2. An electronic door lock/unlatch control for a motor vehicle having an electric power source, an ignition switch connected to the electric power source and at least one front door and one rear door, each of the front and rear doors having a mechanical latch mechanism adapted to latch the door automatically upon door closure and having a mechanical unlatch mechanism driven by an electric motor, when activated, to unlatch and partially open the door, the control comprising, in combination:

a front door unlatch switch;

a first FET having a source and drain connected in series with the front door unlatch switch and electric motor of the front unlatch mechanism across the electric power source, the first FET further having a gate;

a first flip-flop having a Q output connected to the gate of the first FET and set and reset inputs, whereby the first flip-flop may be set to enable conduction of the first FET upon closure of the front door unlatch switch and reset to prevent such conduction;

a front door unlatch switch;

a rear door unlatch switch;

a second FET having a source and drain connected in series with the rear door unlatch switch and the electric motor of the rear unlatch mechanism across the electric power source, the second FET further having a gate;

a second flip-flop having a Q output connected to the gate of the second FET and set and reset inputs, whereby the second flip-flop may be set to enable conduction of the second FET upon closure of the rear door unlatch switch and reset to prevent such conduction;

a front lock switch connected between the electric power source and the reset inputs of the first and second flip-flops so as to reset the first and second flip-flops when closed and thereby disable unlatching of the front and rear doors;

a front unlock switch connected between the electric power source and the set inputs of the first and second flip-flops so as to set the first and second flip-flops when closed and thereby enable unlatching of the front and rear doors;

a rear lock switch connected between the electric power source and the reset input of the second flip-flop so as to reset the second flip-flop when closed and thereby disable unlatching of the rear door;

a rear unlock switch connected between the electric power source and the second flip-flop so as to set the second flip-flop when closed and thereby enable unlatching of the rear door;

a rear unlatch disable switch connected in series with the second FET, rear door unlatch switch and the electric motor of the rear unlatch mechanism across the electric power source, the rear unlatch disable switch being located within reach of a vehicle operator but out of reach of a passenger using the rear door and effective, when open, to prevent unlatching of the rear door;

front lock and unlock indicating LEDs associated with the front door;

rear lock and unlock indicating LEDs associated with the rear door;

an indicating LED drive circuit for each of the front lock, front unlock, rear lock and rear unlock indicating LEDs, each said indicating LED drive circuit comprising a transistor switch in series with the respective LED and electric power source and having a control electrode connected to a logic gate effective to activate the transistor switch to drive the respective LED in response to the simultaneous presence of an enabling input voltage and the Q output of the flip-flop controlling enablement of the unlatching mechanism of the associated door to indicate the lock/unlock status thereof;

an RC timing circuit comprising a capacitor quickly chargeable through a small resistance to a first predetermined voltage and effective, when not being charged, to slowly discharge through a larger resistance, the RC timing circuit providing the enabling input voltage when the capacitor is charged above a second predetermined voltage lower than the first predetermined voltage;

first circuit means including a door jamb switch responsive to the front door and connected to the electric power source, the first circuit means being effective to charge the capacitor of the RC timing circuit through an isolating diode only when front door, as indicated by the door jamb switch, is open; and

second circuit means connecting the electric power source through the ignition switch and a second isolating diode to the capacitor of the RC timing circuit to charge the capacitor through the ignition switch when the ignition switch is closed, the RC timing circuit being effective to provide the enabling input voltage for a predetermined time after the latter of the closure of the front door and opening of the ignition switch as the capacitor discharges from the first predetermined voltage to the second predetermined voltage, whereby the lock/unlock status of the locks is displayed while the ignition switch is closed, while the front door is open and for at least the predetermined time thereafter.