Abstract: A mechanical lock device dispensing with a key capable of unlocking a dead bolt from outside the room when pushbuttons of a number r out of a total number of n are depressed and a locking and unlocking bar of a lock unit and a locking and unlocking member connected thereto are rendered rotatable. The locking and unlocking member is fitted in a control slider. In the control slider, there is disposed a control pin which controls the transmission of the sliding movement of an intermediate slider to the dead bolt. The intermediate slider can be operated by turning a grip. The control pin is controlled by a sub-control slider. In the lock unit, there are disposed two sliding plates which can be carried in accordance with the movement of a permutation driving plate.

Abstract: A mechanical lock device dispensing with a key, wherein a locking and unlocking bar associated with at least one lock unit and a locking and unlocking pawl connected to such bar can be angularly rotated by depressing, in a proper order, pushbuttons of a number r out of a total number n, whereby anybody can operate from outside a dead bolt in a manner to withdraw the same from the mortise. The locking and unlocking pawl is held in engagement within a cutout formed in a control slider fitted in a stem portion of the dead bolt and also in a plurality cutouts formed in the stem portion of the dead bolt and having a larger width than the cutout formed in the control slider. The control slider can be operated by turning a grip. The dead bolt itself can be operated from inside the room irrespective of the position where the locking and unlocking pawl is disposed. The dead bolt can be fitted into a mortise and the lock units can be reset by the reciprocating motion of a lever operated by turning a knob.