Patent GB-1259487-A (GB)
IPC: E05B65/36
Filed: 1969-02-24
Abstract: 1,259,487. Latches. AISIN SEIKI CO. Ltd. 24 Feb., 1969 [23 Feb., 1968 (3)], No. 9718/69. Heading E2A. In an automobile vehicle each of the doors is provided with a pressure responsive control cylinder 37 for selectively locking or unlocking the door, the space in each of said control cylinders being divided into a door locking chamber and a door unlocking chamber, two electromagnetically operated valves being provided in the circuit between a pressure source and the control cylinders for selective supply and interruption of supply of the pressure to said locking or unlocking chambers, the valves being controlled by any one of a plurality of electric switches. The pressure can be positive or negative (in a partial vacuum). In the construction shown the chambers 37a and 37b of the control cylinders 37 are connected via the electromagnetically operated valves to a vacuum reservoir 33 which is itself connected via a check valve means 137 and a pipe 110 to the induction manifold of the vehicle engine. Each of the valves 31 is connected to a plunger 30 of a solenoid 27 or 28 the valves 31 being biassed onto their seats 109 by springs 32 when the solenoid coils 29 are not energised. As shown three switches 11, 17 and 21 are provided for controlling the solenoids each switch being a three position switch having a central off position, a position in which the door unlocking solenoid 28 are energised and a position in which the door locking solenoids are energised; the switch 11 is fitted to the driver's door of the vehicle and is operated by a key; the switch 17 is fitted to the front passenger's door of the vehicle and again is operated by means of a key and the switch 21 is provided inside the vehicle either on the instrument panel or on an armrest of the driver's door. For each door the locking mechanism is part of a lockable latch mechanism which as shown in Fig. 3 has a support bracket having two panel members 44a, 44b at right angles, the panel member 44a carrying a gear bolt (not shown) which is connected via a shaft 45a with a ratchet wheel 45; the ratchet wheel is engaged by a tooth 48 of a pawl 46 to hold the ratchet wheel of the gear bolt in the latching position and the pawl has an extension arm 49 which is engaged by the forked end portion of a lever 50, the lever 50 being biassed by a spring 50 in the direction to hold the pawl in engagement with the ratchet wheel. From the inside of the door the pawl 49 is raised to release the ratchet wheel by means of a link 63; the link 63 is connected by means of a pivot to a bell crank lever 66 which is connected via a rod 121 to the inside door handle; pivoting the bell crank lever 66 raises the link 63 which in turn engages the extension 49 of the pawl 46. The link 63 can also be raised by means of a lever 72 which is pivoted to the panel member 44a and which intermediate its ends is connected to a link 73 which in turn is connected to the outside door handle. The link 63 has a pin and slot connection with a lever 64 which is pivotally carried by the panel member 44b and in one position the lever 64 holds the link 63 so that its end portion is in engagement with the pawl 46 and in another position of the lever 64 the link is disposed so that its end portion cannot engage the pawl 46; the latter position is the locking position. The lever 64 is moved between its two positions by a three armed lever 57 which is pivotally mounted on the panel member 44b and one of whose arms 61 engages the lever 64; another arm 60 is connected to the diaphragm 41 of the control cylinder by a rod 42 so that the control cylinder can move the link 63 between its two positions to place the latch mechanism in the locking and unlocking conditions. The arm 60 is also connected via a rod 62 with a locking button on the inside of the door so that the door can be locked manually. The third arm of the lever is engaged by a lever 53 which is pivotally carried on the panel member 44a and which is connected to the key locking mechanism disposed on the outside of the door enabling the door to be locked and unlocked manually from the outside. In addition the lever 53 is operatively connected with the outside door switch unit 11 or 17 as the case may be through a pin and slot connection 112. In a modification when the vehicle has rear doors the lever 53 is omitted. In a modification of the circuit, the circuit to the switch 21 is completed via the ignition switch and in addition the lead of the switch which goes to the locking solenoid is completed via a switch controlled by the gear shift lever so that when the vehicle is in top gear the doors are automatically locked. A modification of this arrangement is also described in which instead of the switch being controlled by the gear shift lever it consists of the contacts of a relay which is part of a transistorised circuit which includes a switch connected to the speedometer drive cable which produces a series of pulses when the vehicle is in motion, the pulses controlling the transistorised circuit so that when the vehicle is in motion the doors are locked and when the vehicle stops the doors become unlocked automatically.