LOCKING DEVICE AND KEY

Abstract

There is disclosed a key required to have a reduced mechanical strength. When an authentic key is inserted into the keyway in a locking device, only a plunger member starts to move from a standby position toward an operative position. When the plunger member is pushed to the operative position, an operating lever located in the locked position swings to the unlocked position. The operating lever unlocks a locking mechanism that is in a locked state. When an inauthentic key is inserted in the keyway, the plunger member and sleeve member move together to the operative position. The operating lever in the locked position does not swing. Thus, the operating lever maintains the body portion of the locking mechanism locked.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described in detail based on the following figures, wherein:

FIG. 1A is a side elevation in cross section showing the structure of a locking device associated with a first embodiment of the present invention;

FIG. 1B is a cross-sectional view of the locking device, taken on line IA-IA of FIG. 1A;

FIG. 1C is a cross-sectional view of the locking device, taken on line IB-IB of FIG. 1A;

FIG. 2A is a side elevation in cross section of a locking device associated with the first embodiment of the present invention, and in which an inauthentic key has been inserted in the keyway and a sleeve member and a plunger member together have moved to the operative position;

FIG. 2B is a side elevation similar to FIG. 2A, but in which an authentic key has been inserted in the keyway and only the plunger member has moved to the operative position;

FIG. 3 is a perspective view of one example of key for use with the locking device shown in FIGS. 1A-1C;

FIG. 4A is a side elevation in cross section showing the structure of a locking device associated with a second embodiment of the invention;

FIG. 4B is a cross-sectional view of the locking device, taken on line IVA-IVA of FIG. 4A;

FIG. 4C is a cross-sectional view of the locking device, taken on line IVB-IVB of FIG. 4A;

FIG. 5A is a side elevation in cross section of a locking device associated with the second embodiment of the invention, and in which an inauthentic key has been inserted in the keyway and a sleeve member and a plunger member together have moved to the operative position;

FIG. 5B is a side elevation similar to FIG. 5A, but in which an authentic key has been inserted in the keyway and only the plunger member has moved to the operative position; and

FIGS. 6A-6C are enlarged cross sections of portions of the locking device associated with the second embodiment of the invention which contain a storage hole, an outer anchoring hole, and an inner anchoring hole in which an anchoring bar is disposed.

Claims

1. A locking device comprising: a cylindrical case member having an internal space extending in an axial direction;a cylindrical plunger member disposed inside the case member and supported by the case member so as to be movable in the axial direction between a given standby position and a given operative position;a keyway formed inside the plunger member so as to extend in the axial direction, and a key being insertable therein from the axial direction outside of the plunger member when the plunger member is in the standby position; andan operation-selecting unit that, when an authentic key is inserted in the keyway and the plunger member moves from the standby position to the operative position together with the authentic key, operates a key-operated mechanism, and that, when an inauthentic key is inserted in the keyway and the plunger member moves from the standby position to the operative position together with the inauthentic key, maintains the key-operated mechanism in an inoperative state.

2. A locking device comprising: a cylindrical case member having an internal space extending in an axial direction;a cylindrical sleeve member disposed inside the case member and supported by the case member so as to be movable between a given standby position and a given operative position in the axial direction;a plunger member disposed inside the sleeve member so as to be movable in the axial direction, and supported by the case member via the sleeve member so as to be movable between the standby position and the operative position in the axial direction;a keyway which is formed inside the plunger member, extends in the axial direction, and a key being insertable therein from the axial direction outside of the plunger member when the plunger member is in the standby position;a key-judging unit that, when an inauthentic key is inserted in the keyway, connects the sleeve member with the plunger member such that the sleeve member and the plunger member move together in the axial direction, and that, when an authentic key is inserted in the keyway, disconnects the sleeve member from the plunger member; andan interlocking unit that, when an authentic key is inserted in the keyway and the plunger member is moved together with the authentic key into the operative position while the sleeve member disconnected from the plunger member by the key-judging unit is left in the standby position, operates a key-operated mechanism, and that, when an inauthentic key is inserted in the keyway and the sleeve member and the plunger member connected together by the key-judging unit are moved into the operative position together with the inauthentic key, maintains the key-operated mechanism in an inoperative state.

3. A locking device of claim 2, wherein the interlocking unit is an operating lever that is connected to the key-operated mechanism and provided so as to be swung between an OFF position where the key-operated mechanism is kept inoperative and an ON position where the key-operated mechanism is operated.

4. A locking device of claim 3, further comprising: a rotary connection portion provided to the sleeve member and connected rotatable relative to the operating lever; anda pressing portion provided to the plunger member and engaging the operating lever, wherein when the plunger member moves toward the operative position, the pressing portion transmits a pushing force to the operating lever; whrerein,when the rotary connection portion and the pressing portion are in the standby position, the operating lever is retained in the OFF position;when the pressing portion is moved from the standby position toward the operative position while the rotary connection portion is left in the standby position, the operating lever receives the pushing force from the pressing portion and swings toward the ON position with the rotary connection portion as a rotation center; andwhen the pressing portion reaches the operative position, the lever swings to the ON position.

5. A locking device as set forth in claim 2, wherein, the key-judging unit has a plurality of engaging members moving relative to the plunger member in directions perpendicular to the axial direction;wherein when the authentic key is inserted in the keyway, all the engaging members come into engagement with a plurality of engagement portions formed at end portions of the authentic key located in directions perpendicular to the axial direction of the authentic key, disconnecting the sleeve member and the plunger member from each other; andwhen an inauthentic key is inserted in the keyway, at least one of the engaging members comes into abutment with a portion other than the engagement portions of the inauthentic key, and the sleeve member is connected with the plunger member so as to move integrally together in the in the axial direction.

6. A locking device of claim 2, wherein the key-judging unit comprises: outer pin holes formed in the sleeve member and extending perpendicularly to the axial direction, and open to an outer surface of the plunger member;inner pin holes penetrating through the plunger member perpendicularly to the axial direction and registering with the outer pin holes when the sleeve member is in the standby position;outer pins that are movably inserted in the outer pin holes, are biased inwardly, and have inner side end portions that are withdrawably inserted into the inner pin holes; andinner pins that are slidably inserted in the inner pin holes, have outer side end portions that are withdrawably inserted into the outer pin holes, and have their outer side end surfaces brought into abutment with inner side end surfaces of the outer pins when the sleeve member and the plunger member are in the standby position; wherein,when an authentic key is inserted in the keyway, the inner pins have their inner side end surfaces brought into engagement with the authentic key and have the outer side end surfaces of the inner pins and the inner side end surfaces of the outer pins located boundaries between the outer pin holes and the inner pin holes.

7. A locking device of claim 6, wherein when an inauthentic key is inserted in the keyway, the inner pins have the inner side end portions brought into abutment with the inauthentic key, causing the outer side end surfaces of the inner pins and the inner side end surfaces of the outer pins to be positioned inside or outside with respect to the boundaries between the outer pin holes and the inner pin holes.

8. A locking device as set forth in claim 2, further comprising: an outer anchoring hole formed in an inner surface of the case member;a storage hole penetrating through the sleeve member perpendicularly to the axial direction and registering with the outer anchoring hole when the sleeve member is in the standby position;an anchoring member slidably stored in the storage hole, having an outer side end portion that is withdrawably inserted into the outer anchoring hole and having an inner side end portion that abuts against the outer surface of the plunger member; anda biasing member disposed in the outer anchoring hole and resiliently extending and retracting perpendicularly to the axial direction, and acting to press an inner side end portion thereof against the anchoring member when the sleeve member is in the standby position; wherein,when an authentic key is inserted in the keyway and the plunger member starts to move from the standby position toward the operative position, the outer side end portion of the anchoring member is inserted into the outer anchoring hole against the force of the biasing member due to pushing force from the outer surface of the plunger member and the sleeve member is confined in the standby position.

9. A locking device of claim 8, wherein, in the cross-sectional shape of an inner side end portion of the anchoring member in the axial direction, the depthwise dimension in the direction perpendicular to the axial direction increases from the standby position toward the operative position.

10. A locking device of claim 2, further comprising: an outer anchoring hole formed in the inner surface of the case member;an inner anchoring hole formed in the outer surface of the plunger member;a storage hole penetrating through the sleeve member perpendicularly to the axial direction and registering with the outer anchoring hole and with the inner anchoring hole when the plunger member and the sleeve member are in the standby position; andan anchoring member slidably stored in the storage hole, resiliently extending and retracting perpendicularly to the axial direction, having an outer side end portion that is withdrawably inserted into the outer anchoring hole when the plunger member and the sleeve member are in the standby position and, having an inner side end portion that is withdrawably inserted into the inner anchoring hole; wherein,when an authentic key is inserted in the keyway and the plunger member starts to move from the standby position toward the operative position, the anchoring member confines the sleeve member in the standby position; and the inner side end portion of the anchoring member is disengaged from the inner anchoring hole due to a pushing force from the outer surface of the plunger member, andwhen an inauthentic key is inserted in the keyway and the sleeve member and the plunger member start to move from the standby position toward the operative position, the outer side end portion of the anchoring member is disengaged from the outer anchoring holes due to a pushing force from the inner surface of the case member.

11. A locking device of claim 10, wherein in a cross-sectional shape of the inner side end portion of the anchoring member taken in the axial direction, the depthwise dimension in the direction perpendicular to the axial direction increases from the standby position toward the operative position, and in a cross-sectional shape of the outer side end portion of the anchoring member in the axial direction, the depthwise dimension in the direction perpendicular to the axial direction increases from the operative position toward the standby position.

12. A locking device as set forth in claim 8, wherein the anchoring member is so designed that the plunger member is anchored and movement thereof away from the operative position is limited when the plunger member has moved from the operative position to the standby position.

13. A key for use with the locking device as set forth in claim 2, the key comprising: an insertion plate, elongated in the axial direction and insertable into the keyway;a first engagement end portion formed at an end part in the widthwise direction of the insertion plate and having at least one engagement portion;a second engagement end portion formed at the other end part in the widthwise direction of the insertion plate and having at least one engagement portion; andan engagement surface formed at a surface in the thickness direction of the inserion plate and having at least one engagement portion.

14. A key of claim 13, wherein a plurality of reference positions are set on the first engagement end portion, the second engagement end portion, and the engagement surface; and the engagement portions are formed to correspond to the respective reference positions.