GB234117A - A padlock with an alarm attachment - Google Patents

Abstract

234,117. Vadnay, F. von. May 15, 1924, [Convention date]. Padlocks, co-operating with burglar alarms.-A padlock has a hollow shackle in which is contained a thread-like detonating cartridge anchored at its ends to the casing so that attempts to force the shackle from the casing result in an explosion which gives the alarm. The shackle may be hinged, pivoted or sliding. Fig. 1 shows a sliding shackle b secured in the cylindrical casing a by a bolt c which is inserted and removed by a key d. The bolt engages recesses in the limbs of the shackle and one and of the bolt is rotatable relative to the rest of the bolt so that the key can turn the feather e to prevent removal. A projection l is provided in the other end of the bolt to prevent that end dropping out if the casing and bolt are sawn through. A cartridge f is threaded through the hollow shackle and has eyes h through which passes the bolt c. Attempts to prise off the shackle or saw through it, result in the detonation of the cartridge. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the provision of additional explosive packings i which increase the force of the explosion to the extent of injuring the tamperer. This subject-matter does not appear in the Specification as accepted.