Abstract: A door lock assembly having an electrical alarm system includes a piezoelectric element located between the lock bolt of the door lock and the lock frame in order to emit a signal to energize the electrical alarm system when pressure is applied between the lock bolt and the frame.

Abstract: In a permutation lock, a closing bolt is secured within a bore in the lock housing. Setting wheels on the lock housing can be rotated to a position representing the combination of the lock for releasing the closing bolt. Each setting wheel consists of an inner ring and an outer ring which are interconnected for rotational movement as a unit. The setting wheels extend between stops on the housing. One of the stops is displaceable in the axial direction so that the outer rings can be displaced axially relative to the inner rings for changing the combination of the permutation lock.

Abstract: A cylinder lock is provided with a contact carrier for the movable contact of a switch in an electrically operated burglar alarm. A spring mounted on the contact carrier and radially projecting from the casing of the lock is stressed by engagement with the wall of the door aperture receiving the lock and biases the contact carrier toward a switch opening position. When it is attempted to pull the lock from the door, the spring pivots the contact carrier and the alarm is energized.

Abstract: In a window whose sash may be swung in the window frame about hinges having a vertical axis or tilted in bearings about a horizontal axis, the sash and frame have dovetail grooves in which the hinge and bearing elements and other fittings can be installed by means of conforming mounting portions without tools or with simple hand tools.