GB289534A - Improvements relating to spring locks - Google Patents

Abstract

289,534. Tibbles, H. J., and Rely-a- Bell Burglar & Fire Alarm Co., Ltd. Jan. 27, 1927. Hasp fastenings; latches, sliding ; locks operating electric switches ; locks, preventing destruction of; spring locks; striking plates for locks and latches.-The bolt 2 of a spring lock is held in retracted position by a detent 16 pivoted to the casing and urged into engagement with a shoulder 19 on the bolt by a spring 20. the tail of the detent having a rod 22 extending through the casing so as to be engaged by a hasp or like bar, to release the bolt when the hasp-bar &c. is placed in position to be secured by a separate padlock. In place of the rod 22 the tail of the bolt may be bent outwards to be engaged by the hasp-bar. An alternative disposition of detent is shown in dotted lines at 16<1>. A modification is described in which a removable bar is provided with headed studs engaging in key-hole slots in a fixed plate, the head of one of the studs, as it slides into position, engaging and depressing a plate spring having a projection which engages the tail of the detent. In a further modification, Figs. 6, 7, an angle locking bar 30, to which a padlock may be applied as shown, is affixed, by hooks shown, to a plate 31 on the door-post when the door is open, the bar 30 having a projection 32 which enters the lock-casing when the door is closed and operates rod 22 to release the bolt of the door lock. In this case rod 22 does not project from the door, to avoid accidental release of the bolt. Bar 30 is removed when the door is to be used without locking. Any suitable form of detent may be used to retain the bolt retracted, and the striking plate may be combined with an electric switch operated by the shot bolt. According to the Provisional Specification the portion of the bolt projecting when shot may have one or more sheets of hard steel riveted in grooves therein to prevent the bolt from being readily sawn through.