GB687223A - Improvements in and relating to cylinder rim nightlatches - Google Patents

Abstract

687,223. Locks. YALE & TOWNE MANUFACTURING CO. Nov. 14, 1951 [Dec. 18, 1950], No. 30752/50., Class 44 A cylinder rim night latch has an inside lever handle which actuates a coupling member which is selectively displaced from a position for coupling the handle to a latch operating cam to a position in which it locks the knob to the lock casing, the coupling member being movable to said position by key operated mechanism preferably incorporated in the handle. The lever handle 1, Figs. 1 and 2, is formed to recelve a cylinder plug 2 and is provided with a hollow spigot 6 enclosing a rotary sleeve 16 having a cam groove 15, and the spigot is slotted at 8 to form a seating for a slidable coupling member 9 with teeth 10, 11. The outer tooth 10 is adapted in the normal position to engage in a recess 12 in a rotatable lever-handle cam 13 which operates the spring latch bolt 14. The inner tooth 11 projects into the cam groove 15 in sleeve 16 so that on rotation of the latter, coupling member 9 moves along slot 8 to locked position in which the outer tooth 10 engages a recess 7a in the lock case and prevents operation or the handle 1. Rotation of the sleeve 16 is effected by an eccentric projection 5 on the plug 2 which extends into the sleeve and engages a radial projection 17 (Fig. 6) therein. The lever-handle cam 13 is mounted on the inner end of spigot 6 and held by a circlip 19, and is provided with a tongue 20 located between the ends of a spring 21 housed in an annular groove 22 in the casing. A pin 23 on cam 13 extends through a camming aperture 24 in the bolt lath 25 and into the path of a cover cam 26 operated by the bar 27 of the outside cylinder lock 28. In operation, coupling member 9 is normally in position to couple the inside handle with cam 13 so that the latch bolt can be withdrawn by the handle or by the outside lock 28 on insertion of the key. By key actuation of the handle lock 2 the handle can be locked, and at the same time the cam 13 freed so that actuation of the latch by the outside lock 28 is still possible.