GB428489A - Improvements in locks - Google Patents

Abstract

428,489. Locks. GIBBONS, Ltd., J., and GIBBONS, F. J. J., Church Lane, Wolverhampton. Feb. 23, 1934, No. 5978. [Class 44] In a lock having a bolt withdrawable by a key, and a handle which is not connected to but can follow the movements of the bolt, means are provided which prevent movement of the handle when the bolt is in the fully protruded position. A bolt a is pressed upon by a spring b and lever b<1>, and is guided by a stud a<2> and slot a<1>. A key inserted at d engages a shoulder a<4> on the bolt after lifting tumblers e, f, which have slots e<1>, f<1> and gates e<2>, f<2>. A stump a<5> on the bolt is located in slots e<1>, f<1>, when the bolt is fully shot, and in the gates when the bolt is withdrawn. When the bolt is partly shot the stump is in the slot f<1> and gate e<2> the slot f<1> being considerably wider than the slot e<1>; this causing the tumbler f to drop before the tumbler e. An arm h<1>, of a follower h', h<2>, fixed to a spindle i, to which an external handle is attached, contacts with a shoulder g on the bolt. The arm h<2> touches a head k<1> of a rod k due to a spring l pressing between the head and a fixed surface k<2>. The tumbler e has an arm m with a block m<1> at its extremity which touches the inclined end of the rod k when the tumbler is dropped, i.e. when the bolt is fully shot. When the tumbler e is raised, the block m<1> is held clear of the end of rod k, thereby permitting movement of the latter, the handle and the follower h<1>, h<2>. A blade spring c, riveted at c<1>, carries a detent block c<2> which engages a lug a<3> on the bolt a when the latter is fully retracted. A button c<3>, on the spring c, projects from the lock casing and engages the door jamb when the door is closed to move the detent laterally out of engagement with the bolt. Fig. 5 shows a modified arrangement in which a bell-crank lever o<1>, o<2>, replaces the plunger rod mechanism. A tumbler n has a slotted arm n' which engages the lever o<1>, pivoted on a stud o. The handle spindle i and follow h<1>, h<2> are located below the bolt a. When the tumbler n is raised, the arm o<1> is also raised, thus allowing movement of the follower. A stop p is provided. A coiled spring i<1> maintains the follower in contact with the bolt. Specification 13209/11, [Class 44], is referred to.