Lock for a sliding closure

Claim 1

A lock for a sliding closure supported along opppsite edges in a frame having a flange along one of said edges, comprising: a generally channel-shaped body having spaced legs defining an intervening slot opening through one side of said body for receiving said flange, a stop shoulder projecting from one leg, and a threaded bore extending through the other to the plane of said slot, a lock screw with at least one flat threaded in said bore for extension into said slot to directly engage and clamp said body firmly to said flange, and means for releasably locking said screw against turning including a second bore extending through said one leg on an axis transverse to said threaded bore and tangentially intersecting the latter bore, a locking plunger slidable in said second bore having a clearance recess which registers with said threaded bore to permit rotation of the screw in a first unlocking position of said plunger and a flat extending from one side of said recess which registers with said threaded bore for engaging said screw flat to lock said screw against turning in a second locking position of said plunger, a spring urging said plunger to its second position wherein said plunger has an accessible outer end against which finger pressure may be exerted to move the plunger to its unlocking position against the thrust of said spring, and a stop shoulder on the other end of said plunger for limiting movement of the plunger by said spring.