Lock device

A lock device comprising:

• a case member that is attached to a lock target;
• a sleeve member that is housed inside the case member such that the sleeve member is movable relative to the case member along an axial direction;
• a plunger member that is housed inside the sleeve member such that the plunger member is movable along the axial direction;
• tumbler members that are arranged at predetermined intervals in the axial direction inside the plunger member and disposed such that the tumbler members are movable in a direction orthogonal to the axial direction;
• recessed portions that are disposed in an inner wall of the sleeve member;
• tongue portions that are formed on the tumbler members, engage with the recessed portions, and cause the sleeve member and the plunger member to move integrally in the axial direction;
• energizing members that energize the tumbler members in a direction where the tongue portions engage with the recessed portions;
• key insertion holes that are formed in the tumbler members, engage with concavo-tongue portions formed on a regular key inserted into the plunger member, cause the tumbler members to move in a direction where the state of engagement between the tongue portions and the recessed portions is released, and also allow insertion of an irregular key;
• a contact wall that is disposed in the plunger member, is pushed against by a distal end portion of either the regular key or the irregular key inserted into the plunger member, and causes the plunger member to move in the axial direction;
• and
• a manipulable member that is rotatably coupled to the sleeve member and the plunger member, rotates when just the plunger member moves axially relative to the sleeve member, and releases the locked state of the lock target,
• wherein engagement positions where the tongue portions disposed on the tumbler members that are adjacent and the recessed portions engage with each other are arranged such that the engagement positions are offset in a thickness direction of the keys.