GB629854A - Improvements in and relating to door locking means - Google Patents

Abstract

629,854. Door latches. CLARK, J. A. Dec. 16, 1947, No. 33166. Addition to 591,914. [Class 44] In a latch or lock as claimed in the parent Specification, the bearing surface between the opposed circumferential surfaces of the spigot and sleeve is of reduced axial length such that a clearance is provided over a substantial length of the opposed surfaces, so that binding action between spigot and sleeve is not caused by applying lateral force to the handle, and operation of the spindle by frictional connection prevented. In the arrangements shown in Figs. 1 and 4, applied to the construction of Fig. 1 of the prior Specification, clearance A is provided between the sleeve 2 and the spigot 4, contact occurring only at B, so that the alignment of spigot and sleeve can be upset by pressure on the handle without causing binding. Either the spigot or the bore of the sleeve may be tapered to provide the clearance, or an annular rib 4b, Fig. 4, may be formed on the spigot, or a double taper may be used. Similarly, to prevent operation of the sleeve 2 by frictional contact with the escutcheon member 3 after removing the screws securing the latter to the door, the outer surface of the sleeve may be formed with a single or double taper, Fig. 1, or the bore in member 3 may be tapered, Fig. 4. The bearings of reduced axial length may also be provided by ball or roller bearing means between the surfaces.