GB765268A - Improvements in or relating to latching devices - Google Patents

Abstract

765,268. Latch fastenings; hooks. SOC. DES. AGRAFES FRANCAISES ET D'ARTICLES METALLIQUES. Feb. 22, 1955 [March 9, 1954; Dec. 21, 1954], No. 5320/55. Classes 44 and 89 (2). [Also in Group XXXII] A latching device comprises a base-plate 1, a pair of jaws 5, 6 pivoted side-by-side on the said plate, biased in open position and adapted to close upon and grip a stud 10 when they come into contact with the stud, and a locking lever 13 pivotally mounted on one of the jaws 5 and elastically urged into a position engaging the other jaw and adapted to retain the jaws in the closed position gripped around the stud. The device can be used on a door, a vehicle coupling or for other purposes. The plate 1 has a slot 2 to receive the stud 10 and the jaws are mounted on either side of the slot 2 and are provided with recesses 11, 12 to engage the stud 10. The jaws are biased to their open position by a .spring 7 which is connected between pins 8 and 9 on the tails of the jaws. When the stud 10 enters the slot 2 it engages the jaws and moves them to their closed position in which they embrace the stud. The lever 13 is pivoted to the tail of the jaw 5 and one end 13a engages the tail of the jaw 6. The end 13a of the lever 13 or the tail of the jaw 6 or both may be curved or have one or more sloping surfaces to provide automatic compensation for play due to wear. The end 13a of the lever 13 may also have one or more rebates to give alternative fastening positions for the jaws. The lever 13 is released to open the jaws by a push rod 15 which is slidably and rotatably mounted in lugs on the plate 1. The push rod is urged by a spring 19 to a position in which a collar 18 on it keeps the lever 13 in its jaw-locking position. The push rod.also carries a pin 20 which in one position of rotation of the push rod can engage the end 13e of the lever 13 so that when the push rod is moved against the pressure of the spring 19, the pin moves the lever 13 from between the jaws to allow them to open. In an alternative position of rotation of the push rod the pin cannot engage the end 13e of the lever so that sliding movement of the push rod is then ineffective to release the jaws. To position the push rod in its alternative positions of rotation a cam 21 is mounted on the push rod and this has two flat surfaces which can alternately engage the plate 1. When the device is used on a door the push rod can be moved slidably or rotated from the inside of the door by a push button 15a on one end of the rod 15 and it can be slidably moved but not rotated from the outside of the door by the engagement of a lever with the other end 15b of the push rod. Thus the door can be locked from the inside by rotating the rod 15 so that it cannot be opened from the outside. In a modification, Figs. 8 and 11, the push rod 15 is not used. Instead a fork-shaped member 28 is pivotally mounted on the plate 1 and engages a finger 27 on the lever 13. A spring 30 urges the forked member in a direction such that the lever 13 tends to be held in its locking position. Mounted on a pivot 29 which carries the forked member 28 is a cranked lever 31. This lever has a limb 31a which when the device is used on a door can be engaged from the outside of the door and which can be moved so as to abut against the forked member 28 to free the lever 13 so that the jaws can open. Movement of the lever 31 can be prevented by a slidable stop member 33 which is operated by a knob 37 from the inside of the door and which can abut against an arm 31b of the lever 31 to prevent its movement. The forked member 28 can also be moved from the inside of the door in order to release the lever 13 by means of a pivoted lever 38, one end of which engages a part 28c upstanding from the forked member.