GB189825A - Improvements in and relating to locks - Google Patents

Abstract

189,825. Castell, J. H. July 2, 1921. Locks, revolving-barrel; lock-mechanism, masterkey; key, retaining until bolt is operated; locks, square-key and like.-In rotary latch locks, applicable for use in sets operable by one key, a recess 5 in the head 6 of the key fits the head 4 of the latch spindle 2, and the recess and head are formed with cameo and intaglio symbols, which, in engaging, enable the key to depress spring-pressed pins 8 mounted in the casing 1 and engaging recesses 9 in the head 4 of the spindle, to release the spindle. A group of locks may have the same symbol, in which case secondary interengaging means between the spindle and key are provided in the form of projections 14 on the spindle and recesses 15 in the key, a different number of the projections and recesses being provided for each particular lock. Axial movement of the spindle 2 in the casing 1 is prevented by providing the spindle 2 with a projection 2* capable of being inserted into an annular groove 1* in the casing 1 through a slot 1**. In order to provide that the key can only be inserted in and withdrawn from the lock when the latch is in its operative position, the front edge of the casing 1 is formed with a flange 11 so shaped as to permit the key to be placed on the spindle 2 when the latch is in the operative position, but engaging the corners of the head of the key when the latter is rotated, the key being prevented from moving through such an angle as to bring its head free of the flange 11 by means of a projection 12 on the key moving in a recess 13 in the outer face of the casing 1. Each key may have a repetition of its symbol on any convenient part for the purpose of identification. According to the Provisional Specification, a master key may be employed for a number of sets of locks.