Abstract: A lock for fire-escape door provided with an actuating member having an integrally formed tongue to block the retraction of a main latch from a protruded position provides higher security to the lock. The lock includes: a housing; a pivotable main latch and a pivotable auxiliary latch which are urged by springs to protrude outside of the housing; and an actuating member adapted to keep the main latch protruded out of the housing and operable with a push plate to release the main latch from being kept protruded. The auxiliary latch has a side projection which stops the actuating member at a first position where the auxiliary latch is protruded and the tongue is so disposed to be accommodated by an inner recess of the main latch such that the main latch is free to retract from the protruded position; the same side projection also stops the actuating member at a second position where the auxiliary latch is retracted and the main latch is protruded.

Abstract: A lock device is provided in which the locking bolt can be actuated by turning the outside lock cylinder or the thumbturn to releasably interlock the housing fixed to the inside surface of the door with a strike attached to the door frame. An inside lock cylinder is rotatably provided in the thumbturn and is designed to releasably lock the thumbturn. The lock device can not be dismounted from the inside of a room by an unauthorized person since all screws for mounting the housing are concealed within the housing, when the door is locked by the outside lock cylinder and the thumbturn is also locked with the inside lock cylinder.

Abstract: The invention relates to an improved construction for a cylinder lock and key, more particularly to a cylinder lock which has a plurality of pin tumblers of different lengths and diameters arranged radially about the axis of a rotatable cylinder, a pin tumbler longitudinally provided at the rear end of a stationary cylinder, a ball being further provided between said rotatable cylinder and stationary cylinder, and a matching key which comprises a tubular shank having thereon a plurality of depressions corresponding to said radially arranged pin tumblers.