Abstract: A lock for overlapping parallel sliding members has a hinge member having two leaves. The two leaves include a fixed leaf permanently secured to one of overlapping sliding members, and a pivotal leaf pivotally moveable between locked and unlocked positions, to permit sliding of said overlapping members in the unlocked position, and, when turned an about 90 degree angle to the locked position, to abut the face of one of said overlapping members to prevent displacement there between. A resistance mechanism is provided for lightly-resisting pivoting of said pivotal leaf against displacement or rotation in the locked position, said resistance mechanism being indestructible in normal operation without pre-manipulation of any portion of the lock prior to pivoting movement.

Abstract: A lock for overlapping parallel sliding members has a hinge member having two leaves. The two leaves include a fixed leaf permanently secured to one of overlapping sliding members, and a pivotal leaf pivotally moveable between locked and unlocked positions, to permit sliding of said overlapping members in the unlocked position, and, when turned an about 90 degree angle to the locked position, to abut the face of one of said overlapping members to prevent displacement there between. A resistance mechanism is provided for lightly-resisting pivoting of said pivotal leaf against displacement or rotation in the locked position, said resistance mechanism being indestructible in normal operation without pre-manipulation of any portion of the lock prior to pivoting movement.