Patent GB-644224-A (GB)
Title: Improvements in door control mechanism
IPC: E05B65/32
Filed: 1948-04-30
Abstract: 644,224. Door latches. SCHONITZER PRODUCTS CO. April 30, 1948, No. 11864. Convention date, May 7, 1947. [Class 44] In a door latch for vehicles of the kind having a pivoted latch member L, Fig. 15, carried on the door for engagement with a fixed stud on the door frame, the latch member is mounted on a shaft 14, Fig. 3, carrying, inside the latch housing, a controlling disc 17 cooperating with a detent D for releasably holding the latch in the latched position, movement of the detent being restrained in the locked condition by a member R movable into and out of the locking position from either side of the door. The latch is biassed towards the unlatching position by a spring 18 so that it tends to throw the door open when released. The spring is loaded by the closing movement of the door. A secondary shoulder 40 may be provided on the disc 17 to retain the latch in a partly latched position. The detent D is biassed to the retaining position by a spring 25. In the unlocked condition the detent is operable by an outside push-button B having a pin 39 engaging the flange 38 of a lever 29, a shoulder 32 of which engages the detent at 33. The detent may also be operated by an inside push-button engaging an arm on a rock-shaft 46, a flattened end 47, Fig. 5, of which fits in one of a pair of slots formed in a pawl member 43 engaging a surface 45 of the detent. The parts being arranged as shown, where the inside push-button is situated below the line of the shaft, actuation causes counter-clockwise rotation of the pawl 43 and clockwise rotation and release of the detent. Should the button be situated, for convenience, above the line of the shaft, the pawl is turned through a right angle (by fitting the shaft 46 in the other pair of slots) so that it bears on the flange 31 of the lever 29 to cause release of the detent. The restraining member R, Fig. 5, is pivoted at 55 and has a nose 56 adapted to engage over the detent D in the locking position. Any attempt to move the detent to the release position merely causes the nose 56 to press harder against the wall 7 of the latch housing. In the unlocking position the nose of the member R is disposed clear of the detent D. An inside operating knob 64 is connected by a link 62 to move the member R into and out of the restraining position. This is also effected by an outside key lock A, Fig. 3, having two extreme positions and a neutral position in which the key may be withdrawn. It is mounted on a shaft 72 carrying arm 68, Fig. 5, having a pin and slot connection with a link 65 pivoted to the member R. Because of the lost motion in the pin and slot connection, the member R may be moved from the inside without affecting the lock. The arm 68 is turned into its extreme positions to shift the member R from one position to the other. The member R is retained in either of its alternative positions by an over-centre spring 55a. The latch member L, Fig. 15, cooperates with a sliding wedge 110 which is spring-loaded so that vibration causes tightening of the pin K against the latch. The latch is modified for use with back doors, as shown in Fig. 19, by. having a remote control for the restraining member 125 consisting of a link 121 pivoted at its ends to the restraining member and a crank lever 118 operated by a knob 117. No key lock is provided. The outside pushbutton may be replaced by a pivoted handle loaded by a spring to the closed position and having a part engaging the release lever when the handle is pulled. In a modification. Fig. 27, the restraining member R carries a tooth 81 engaging between a pair of abutments 82, 83 on a quadrant 84 centred by a spring 93. Teeth 85 of the quadrant mate with teeth 86 on an arm 87 operated by the key lock. The lost motion in this modification is provided by the space between the abutments 82 and 83. The latch mechanism is accommodated in a housing closed by a plate 8, Fig. 5, to exclude dust &c. The window guide 54 passes close to or is in contact with the cover 8. Specifications 501,613, 528,082 are referred to.