Lock device

A lock device includes: 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 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; a coupling structure in which a key insertion hole that allows insertion of a key is formed, the coupling structure being placed inside the plunger member and coupling together the sleeve member and the plunger member; and a manipulable member that is rotatably coupled to the sleeve member and the plunger member, rotates when just the plunger member moves, and releases the locked state of the lock target. The coupling structure is configured to release the coupling just when a regular key is inserted into the key insertion hole.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese Patent Application No. 2007-92813, the disclosure of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lock device that locks and unlocks a lock mechanism or the like by manipulation of a key inserted into a key insertion hole.

2. Description of the Related Art

A lock device disposed in a door of an automobile or the like is, for example, disposed with a cylindrical case member, a sleeve member that is rotatably disposed inside the case member, a plunger member that is rotatably disposed inside the sleeve member, a rear rotor that is rotatably disposed so as to face the plunger member in an axial direction, and a lock lever that is disposed so as to rotate integrally with the rear rotor (e.g., see Japanese Patent Application Publication (JP-A) No. 8-4387).

This lock device is configured such that, when a regular key is inserted into a key hole, the plunger member releases the state of engagement between the plunger member and the sleeve member, just the plunger member becomes rotatable, and the plunger member can cause the rear rotor to rotate. Thus, the lock lever rotates together with the rear rotor, and a lock mechanism in a door of a vehicle or the like is unlocked by the manipulating force of the lock lever.

Further, when a key substitute, such as a key whose shape is different from that of the regular key or a driver (these will generically be called an “irregular key” below), is inserted into the key hole in the plunger member and forcibly rotated, tumbler members maintain the state of engagement between the plunger member and the sleeve member, and the plunger member and the sleeve member integrally rotate, so the plunger member cannot cause the rear rotor to rotate.

In other words, the lock device is configured such that the plunger member and the sleeve member integrally rotate even when an irregular key that has been inserted into the plunger member is rotated, but the rear rotor and the lock lever cannot be caused to rotate, and the lock mechanism is not unlocked.

That is, in the lock device described in JP-A No. 8-4387, when the regular key is inserted into the key hole and the plunger member is caused to rotate, the lock mechanism can be unlocked, but when the irregular key is inserted into the key hole and the irregular key is forcibly rotated, the plunger member and the sleeve member rotate together, so the lock mechanism is not unlocked. Moreover, because the plunger member and the sleeve member rotate together, unreasonable force does not act on the tumbler members that engage the plunger member and the sleeve member, so the lock device is structured such that damage to the tumbler members and the like is prevented.

However, when the lock device is to be unlocked, a plate-shaped key must be inserted into the key hole in the lock device and rotated counter to the rotational resistance of the plunger member, the rear rotor and the lock lever and the actuated resistance of the lock mechanism.

For this reason, in regard to the key used in this lock device, the material thereof is limited to a high-strength material such as iron or stainless steel, and it is necessary to make the thickness of the key sufficiently thick in accordance with the size of the transfer torque.

Further, in this lock device, plural plate-shaped tumbler members arranged in the plunger member are disposed at predetermined intervals in the axial direction and so as to be movable in an axis-orthogonal direction. When a key is inserted into the key hole, the concavo-tongue portions of the key and the key insertion hole in the plunger member contact each other. In the case of the regular key, all of the tumbler members move to regular positions and just the plunger member rotates, but in the case of the irregular key, at least one of the tumbler members moves to an irregular position, the plunger member and the sleeve member integrally rotate, and the rear rotor cannot be caused to rotate.

On the other hand, it is necessary to increase the number of the tumbler members in order to diversify the types of keys, and there is also the problem that the axial direction length of the plunger member must be made longer when the number of the tumbler members disposed at predetermined intervals in the plunger member is increased.

SUMMARY OF THE INVENTION

In consideration of the above-described circumstances, the present invention provides a lock device that can make the mechanical strength required of the key small and control the length of the plunger member from becoming longer even when the number of the tumbler members is increased.

A first aspect of the invention is a lock device including: 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 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, 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.

According to this configuration, when the irregular key is inserted into the plunger, the state of engagement between the tongue portions formed on the tumbler members and the recessed portions formed in the sleeve member is maintained, and the sleeve member and the plunger member move integrally in the axial direction inside the case member even when the distal end portion of the irregular key pushes the contact wall of the plunger member. For this reason, the manipulable member maintains the locked state of the lock target.

On the other hand, when the regular key is inserted into the plunger member, the key insertion holes disposed in the tumbler members engage with the concavo-tongue portions formed on the regular key. Thus, the tumbler members move in a direction where the state of engagement between the tongue portions and the recessed portions is released counter to the energizing force of the energizing members that energize the tumbler members such that the tongue portions engage with the recessed portions.

Moreover, when the distal end portion of the regular key pushes the contact wall of the plunger member, just the plunger member moves inside the sleeve member. In this manner, just the plunger member moves, whereby the manipulable member releases the locked state of the lock target.

Consequently, the locked state of the lock target can be released simply by a user inserting the regular key into the plunger member and pushing this regular key. For this reason, it is not necessary to load a force in the rotational direction on the key and the mechanical strength along the turning direction required of the key can be made small in comparison to a rotary lock device where manipulation of the lock mechanism is performed by rotating the key after inserting the key into the plunger.

On the other hand, when the user tries to remove the regular key from the plunger member after releasing the locked state of the lock target, the state of engagement between the concavo-tongue portions formed on the regular key and the key insertion holes disposed in the tumbler members is maintained, and the plunger member moves and returns to its original position integrally with the removal of the regular key.

At this time, in order for the tongue portions of the tumbler members to engage with recessed portions other than the recessed portions with which the tumbler members had been initially engaged and not obstruct the movement of the plunger member, the attachment pitch of the tumbler members must be made longer than the moving distance (stroke) of the plunger member. In other words, the length of the plunger member ends up becoming longer when the number of the tumbler members is increased in order to diversify the types of keys.

However, in the present invention, the engagement positions where the tongue portions and the recessed portions engage with each other are arranged such that the engagement positions are offset in a thickness direction of the keys. For this reason, while the plunger member is being pushed, even when the regular key is removed from the plunger member and the tumbler members are returned to their initial positions by the energizing force of the energizing members, the tongue portions do not engage with recessed portions other than the recessed portions with which the tongue portions had initially been engaged. In other words, the length of the plunger member can be controlled from becoming longer even when the number of the tumbler members is increased.

In the lock device of the above-described aspect of the present invention, there may be three of the engagement positions in the thickness direction of the keys.

According to this configuration, there are three of the engagement positions in the thickness direction of the keys, so by creating three tumbler members whose tongue portions are offset, the length of the plunger member can be controlled from becoming longer even when the number of the tumbler members is increased.

In the lock device of the above-described aspect of the present invention, the engagement positions may be arranged in a staggered manner in the thickness direction of the keys.

According to this configuration, the engagement positions are arranged in a staggered manner in the thickness direction of the keys, so the tumbler members can be inverted and used, and the number of types of the tumbler members can be reduced.

According to the lock device of the present invention, the lock device makes the mechanical strength required of the key small and controls the length of the plunger member from becoming longer even when the number of the tumbler members is increased.

DETAILED DESCRIPTION OF THE INVENTION

A lock device10pertaining to a first embodiment of the present invention will be described in accordance withFIG. 1AandFIG. 1BtoFIG. 8.

The lock device10of the present invention shown inFIG. 1Ais disposed as part of a lock mechanism for locking and unlocking an open/close member, such as a door in an automobile, a trunk lid, or the lid of a glove box (lock target), and is used for a user to manipulate the lock mechanism (not shown) from a locked state to an unlocked state by a key12.

A square cylinder-shaped case member14is disposed in the lock device10as an outer shell portion of the device. The case member14is formed so as to be long and narrow in an axial direction (direction of line S in the drawings) and, as shown inFIG. 4AandFIG. 4B, has a substantially rectangular shape whose cross-sectional shape along a direction orthogonal to the axial direction of its peripheral wall portion (axis-orthogonal direction) is long in a height direction (direction of arrow H). Further, a lid portion16is formed in the case member14shown inFIG. 1Aso as to close an opening on a distal end side (left side inFIG. 1A) of the case member14along the axial direction. A rectangular open portion18, into whose center portion the key12is insertable, is formed in the lid portion16. Moreover, a plate-shaped lever guide20that extends along the axial direction is integrally formed on the case member14on the lower end side of the rear end portion thereof.

The case member14of the lock device10is disposed inside a door or the like in which the lock mechanism is housed, and the case member14is fixed such that the open portion18faces the outside from the inside of the door or the like.

Moreover, the lock device10is disposed with a square cylinder-shaped sleeve member22that is disposed inside the case member14. The sleeve member22is formed so as to be long and narrow in the axial direction and has a substantially rectangular shape whose cross-sectional shape along the axis-orthogonal direction of its peripheral wall portion is long in the height direction. The sleeve member22is inserted into the inside of the case member14and is supported by the case member14so as to be movable between a standby position shown inFIG. 1Aand an actuated position shown inFIG. 3.

Further, the sleeve member22is configured such that its distal end surface contacts the inside of the lid portion16in a state where the sleeve member is in the standby position shown inFIG. 1Aand such that the sleeve member22reaches the actuated position when the sleeve member22slides rearward a predetermined actuation stroke D (seeFIG. 3) from the standby position.

Moreover, a plunger storage chamber24that is a space penetrating the sleeve member22in the axial direction is formed inside the sleeve member22. Further, in the axial direction intermediate portion of an outer peripheral surface of the sleeve member22, a step portion26is formed, a sleeve body28is formed on a distal end side via the step portion26, and a spring holding portion30is formed on a rear end side.

The dimension of the spring holding portion30along the height direction (direction of arrow H inFIG. 4AandFIG. 4B) and a width direction (direction of arrow W inFIG. 4AandFIG. 4B) is smaller than that of the sleeve body28, and a coil spring32including a winding portion bent in a substantially rectangular shape is disposed on the outer peripheral side of the spring holding portion30.

Further, a lid portion34is formed on the sleeve member22so as to close an opening on a rear end side of the lid portion34. A rod guide hole36that penetrates the lid portion34in the axial direction is formed in the center portion of the lid portion34. Moreover, a slide lever38that extends from the lower end portion of the lid portion34towards the rear end side along the axial direction is integrally formed on the sleeve member22. The lower end surface of the slide lever38is allowed to slidably contact the upper end surface of the lever guide20in the case member14.

The outer peripheral surface of a cross-sectionally rectangular receiving member40that holds the rear end of the coil spring32is attached to the rear end portion of the case member14, and the inner peripheral surface of the receiving member40slidably contacts the outer peripheral surface of the spring holding portion30. Because of this configuration, the coil spring32is compressed and disposed between the step portion26of the sleeve member22and the receiving member40, and the coil spring32always energizes the sleeve member22into the standby position.

Further, the lock device10is disposed with a plunger member42that is disposed inside the plunger storage chamber24of the sleeve member22. The plunger member42is formed in a substantially square column shape (seeFIG. 6) that is long and narrow in the axial direction, and the plunger member42is disposed with a plunger body42A that is inserted into the inside of the plunger storage chamber24on the distal end side and a plunger rod42B that projects in the axial direction from the rear end surface of the plunger body42A.

The plunger body42A is slidably inserted into the inside of the plunger storage chamber24and is supported by the case member14via the sleeve member22so as to be movable between a predetermined standby position (seeFIG. 1A) and an actuated position (seeFIG. 3).

The distal end surface of the plunger member42contacts the inside of the lid portion16in a state where the plunger member42is in the standby position, and the plunger member42reaches the actuated position when the plunger member42slides rearward the predetermined actuation stroke D (seeFIG. 2andFIG. 3) from the standby position. The details of the stroke D will be described later.

Moreover, the rear end side of the plunger rod42B of the plunger member42projects to the outside of the sleeve member22through the rod guide hole36in the sleeve member22. Further, the lower end surface of the plunger rob42B projecting from the rod guide hole36slidably contacts, in the axial direction, the upper end surface of the slide lever38.

Moreover, a key hole48disposed along the axial direction is formed in the central portion of the plunger body42A, and the cross-sectional shape of the key hole48has a rectangular shape that is long and narrow along the height direction of the lock device10. The cross-sectional shape of the key hole48corresponds to the shape of the key12that corresponds to the specifications of the lock device10pertaining to the present embodiment, and the key12is configured to be insertable into and removable from the key hole48.

As shown inFIG. 8, the portion of the key12that is inserted into the key hole48is formed in a long and narrow plate shape and is manufactured using a material such as metal, resin, paper, or a composite material of these, for example. Further, an insertion guide portion50whose thickness becomes thinner in a sloping manner from its proximal end side towards its distal end side is formed on the distal end portion of the key12.

Moreover, one end surface and the other end surface of the key12along a direction orthogonal to the longitudinal direction thereof are configured as an upper engaging end52and a lower engaging end54. The key12is inserted by a user into the key hole48with an orientation where the upper engaging end52faces up along the height direction of the device.

Further, six engagement positions PE1to PE6that are mutually different along the longitudinal direction of the key12(axial direction of the device) are disposed on the upper engaging end52and the lower engaging end54of the key12, and upper engaged portion58and lower engaged portions60that are selectively recessed in “V” shapes are disposed in the engagement positions PE1to PE6.

Further, as shown inFIG. 1A, plural (six in the present embodiment) tumbler storage chambers120,122,124,126,128and130are formed as slits in the plunger body42A. The tumbler storage chambers120,122,124,126,128and130are arrayed at a substantially equal pitch along the axial direction, and this pitch is substantially equal to the pitch of the six engagement positions PE1to PE6of the key12(seeFIG. 4AandFIG. 4B).

Moreover, an upper end open portion42C and a lower end open portion42D (seeFIG. 4AandFIG. 4B) are disposed in the upper end portion and the lower end portion of each of the tumbler storage chambers120,122,124,126,128and130, and tumbler plates66and68that are substantially tabular members are disposed inside the tumbler storage chambers120,122,124,126,128and130. Here, an attachment pitch P of the tumbler plates66and68is set to be larger than half of the stroke D of the aforementioned plunger member42from the standby position to the actuated position. The details of the relationship between the attachment pitch and the stroke D will be described later.

Further, as shown inFIG. 4A, the tumbler plates66are disposed so as to be movable along the height direction inside the tumbler storage chambers122,126and130that are disposed in the even number places from the distal end portion. Engaging tongue portions66A that protrude from one side (the left side shown inFIG. 4A) of the upper surface of the plunger member42and engage with engaging recessed portions62disposed in the sleeve member22are disposed on the upper end portions of the tumbler plates66.

Moreover, projecting portions66B that project from the other side (the right side shown inFIG. 4A) of the lower surface of the plunger member42and engage with meshing recessed portions74disposed in the sleeve member22when the tumbler plates66move downward are disposed on the lower end portions of the tumbler plates66. Further, rectangular key insertion holes66C that extend up and down are disposed in the center portions of the tumbler plates66, and the key insertion holes66C are communicated with the key hole48(seeFIG. 1A).

As shown inFIG. 4B, the tumbler plates68are disposed so as to be movable along the height direction inside the tumbler storage chambers120,124and128that are disposed in the odd number places from the distal end portion. Engaging tongue portions68A that protrude from one side (the right side shown inFIG. 4B) of the upper surface of the plunger member42and engage with the engaging recessed portions62disposed in the sleeve member22are disposed on the upper end portions of the tumbler plates68. Projecting portions68B that project from the other side (the left side shown inFIG. 4A) of the lower surface of the plunger member42and engage with the meshing recessed portions74disposed in the sleeve member22when the tumbler plates68move downward are disposed on the lower end portions of the tumbler plates68. Further, rectangular key insertion holes68C that extend up and down are disposed in the center portions of the tumbler plates68, and the key insertion holes66C are communicated with the key hole48(seeFIG. 1A).

Moreover, coil springs72that energize the tumbler plates66and68upward are disposed in the tumbler storage chambers120,122,124,126,128and130, and in a state where the key12(seeFIG. 1A) is not inserted into the key hole48(seeFIG. 1A), the engaging tongue portions66A and68A disposed on the upper ends of the tumbler plates66and68are energized by the coil springs72and engage with the engaging recessed portions62of the sleeve member22.

In this state, as shown inFIG. 6andFIG. 7, the engaging tongue portions66A and the engaging tongue portions68A are arranged in a staggered manner as a result of being offset in the thickness direction of the key. In other words, engagement positions46between the engaging tongue portions66A and68A and the engaging recessed portions62shown inFIG. 4AandFIG. 4Bare also arranged in a staggered manner in the thickness direction of the key. It will be noted that inFIG. 6, the sleeve member22and the like are omitted in order to make it easier to understand the arranged state of the engaging tongue portions66A and68A.

As shown inFIG. 1A, the lock device10is configured such that, when the key12is inserted into the key hole48in the plunger member42in the standby position, the key12passes through the key insertion holes66C and68C in the tumbler plates66and68, the upper edge portions or the lower edge portions of the key insertion holes66C and68C in the tumbler plates66and68engage with the upper engaged portions58or the lower engaged portions60(seeFIG. 8) of the key12, and the tumbler plates66and68move in the height direction counter to the energizing force of the coil springs72.

Consequently, the lock device10is configured such that, when the key12is inserted into the key hole48, the six tumbler plates66and68move along the height direction (sliding direction) to positions corresponding to the upper engaged portions58and the lower engaged portions60of the key12. Here, a key code for unlocking the lock device10is imparted beforehand to the lock device10, and the shapes (depths) of the upper engaged portions58and the lower engaged portions60that become the engagement partners of the tumbler plates66and68are set in accordance with the key code.

As long as the key12is suited to the specifications of the lock device10pertaining to the present embodiment, the key12is insertable into and removable from the key hole48, but as the key12, there is one where the shapes of all of its upper engaged portions58and its lower engaged portions60that become the engagement partners of the tumbler plates66and68correspond to the key code (this will be called a “regular key12R” below) and one whose shape does not correspond to the key code and does not match that of the regular key12R (this will be called an “irregular key12I” below).

When the regular key12R is inserted into the key hole48, the six tumbler plates66and68move to regular positions corresponding to the upper engaged portions58and the lower engaged portions60such that the state of engagement between the engaging tongue portions66A and68A and the engaging recessed portions62is released.

In other words, all of the tumbler plates66and68move downward such that the engaging tongue portions66A and68A move away from the engaging recessed portions62, and the tumbler plates66and68move to the regular positions shown inFIG. 5AandFIG. 5B. At this time, moreover, as shown inFIG. 5CandFIG. 5D, the tumbler plates66and68do not move too far downward and the projecting portions66B and68B of the tumbler plates66and68do not engage with the meshing recessed portions74.

In this manner, when all of the tumbler plates66and68move to the regular positions, the engagement between the sleeve member22and the plunger member42is released, and when the normal key12R is pushed further in the axial direction, the distal end portion of the normal key12R pushes a contact wall42E formed in the bottom of the plunger member, the sleeve member22is restrained in the standby position by a later-described locking bar108as shown inFIG. 2, and just the plunger member42slides inside the sleeve member22and moves to the actuated position.

Further, the lock device10is configured such that, when the irregular key12I is inserted into the key hole48shown inFIG. 1A, the tumbler plates66and68moves to positions corresponding to the upper engaged portions58and the lower engaged portions60(seeFIG. 8) of the key12, and at least one of the tumbler plates66and68moves to an irregular position, so the state of engagement between the engaging tongue portions66A and68A and the engaging recessed portions62is maintained, or the projecting portions66B and68B and the meshing recessed portions74engage with each other.

In this manner, when at least one of the tumbler plates66and68moves to an irregular position, the state of engagement between the sleeve member22and the plunger member42is not released, and when the irregular key12I is further pushed in the axial direction, as shown inFIG. 3, the later-described locking bar108is held in a storage hole106, and the plunger member42slides inside the case member14counter to the energizing force of the coil spring32together with the sleeve member22and moves to the actuated position.

As shown inFIG. 1A, a plate-shaped actuating lever92that is coupled to the rear end portion of the plunger rod42B and coupled to the end portion of the slide lever38is disposed in the lock device10, and the actuating lever92is bent in a substantial “L” shape.

A slot-like coupling hole94that is long in the longitudinal direction is formed in a proximal end portion (inFIG. 1A, the lower end portion) of the actuating lever92. Further, a circular column-shaped coupling shaft96whose axial direction is in the width direction of the device is disposed in the slide lever38, and the coupling shaft96is inserted into the coupling hole94in the actuating lever92and configured to be movable along the longitudinal direction of the coupling hole94. Thus, the actuating lever92is swingably coupled to the slide lever38.

Further, a circular column-shaped pushing shaft98whose axial direction is in the width direction is disposed in the rear end portion of the plunger rod42B. The pushing shaft98penetrates a corner portion of the L-shaped actuating lever92and is rotatably coupled to the actuating lever92.

Moreover, the distal end of the actuating lever92is disposed so as to extend rearward from the pushing shaft98, and a circular cylinder-shaped bearing member118is attached to the distal end portion of the actuating lever92. Further, an upper end portion of a long and narrow round bar-shaped coupling rod100, which upper end portion is bent in an “L” shape, is rotatably coupled to the bearing member118. Moreover, the coupling rod100is disposed so as to extend along the height direction, and the lower end portion of the coupling rod100is coupled to the lock mechanism (not shown).

Because of this configuration, the actuating lever92is disposed so as to be swingable between a predetermined locked position (seeFIG. 1A) and an unlocked position (seeFIG. 2) about the coupling shaft96of the slide lever38.

It will be noted that the positions of the coupling shaft96and the pushing shaft98are set such that, as shown inFIG. 1A, in a state where the sleeve member22and the plunger member42are in the standby positions, the actuating lever92is held in the locked position, and as shown inFIG. 2, in a state where the sleeve member22is in the standby position and just the plunger member42has moved the stroke D from the standby position to the actuated position, the actuating lever92swings to the unlocked position.

In this manner, when the actuating lever92swings from the locked position to the unlocked position, it causes the coupling rod100to move downward and transmit pushing force (manipulating force) to the lock mechanism via the coupling rod100. When the lock mechanism receives this operating force, it changes from a locked state to an unlocked state to enable an open/close member such as a door, a trunk lid, or the lid of a glove box that had been locked by the lock mechanism to be opened.

As shown inFIG. 3, when the sleeve member22and the plunger member42integrally move from the standby positions to the actuated positions, the relative positional relationship between the pushing shaft98and the coupling shaft96does not change, so the actuating lever92is held in the locked position. Consequently, the lock device is maintained in the locked state and is not unlocked. In this state, when the user stops pushing the key12(in this case, a key whose shape is different from that of the regular key12R), the sleeve member22and the plunger member42in the actuated positions are returned to the standby positions by the energizing force of the coil spring32.

Further, as shown inFIG. 1A, a recessed inner peripheral locking hole102is formed in the upper end portion and the lower end portion of the outer peripheral surface of the plunger body42A, and a recessed outer peripheral locking hole104is formed in the upper end portion and the lower end portion of the inner peripheral surface of the case member14. The inner peripheral locking hole102is disposed on the rear end side of the tumbler plates66, and the outer peripheral locking hole104is disposed so as to be in the same position as the inner peripheral locking hole102along the axial direction and the width direction of the device when the plunger member42is in the standby position.

Moreover, the storage hole106is formed in the sleeve member22so as to penetrate the sleeve member22along the axis-orthogonal direction. The storage hole106is disposed so as to be in the same position as the outer peripheral locking hole104and the inner peripheral locking hole102along the axial direction and the width direction in a state where the sleeve member22and the plunger member42are in the standby positions. Further, the cross-sectional shapes along the axial direction of the outer peripheral locking hole104, the inner peripheral locking hole102and the storage hole106match each other.

Moreover, the substantially square column-shaped locking bar108is stored, so as to be slidable along the axis-orthogonal direction, inside the storage hole106, and an energizing plate110and a spring112are inserted into the outer peripheral locking hole104. The outer peripheral side of the locking bar108is configured as a flat surface whose end surface is parallel to the axial direction, and the distal end surface of the locking bar108is configured as a flat cam surface116that slants towards the outer peripheral side from the rear end along the axial direction towards the distal end.

Moreover, the locking bar108is configured such that its rear end portion is insertable into and removable from the outer peripheral locking hole104in state where its rear end surface is caused to pressingly contact the plate-shaped energizing plate110when the sleeve member22is in the standby position. Further, when the sleeve member22and the plunger member42are in the same position along the axial direction, the distal end portion of the locking bar108is removably inserted into the inner peripheral locking hole102and caused to pressingly contact the bottom surface portion of the inner peripheral locking hole102. The energizing plate110is slidably inserted into the outer peripheral locking hole104, and the spring112is disposed in a compressed state between the energizing plate110and the bottom surface portion of the outer peripheral locking hole104.

When the regular key12R is inserted into the key hole48and the plunger member42starts moving from the standby position to the actuated position, the cam surface116of the locking bar108receives a partial force (pushing force) along the axis-orthogonal direction from the outer peripheral surface of the plunger member42, whereby the locking bar108is pushed out towards the outer peripheral side counter to the energizing force of the spring112. Thus, as shown inFIG. 2, the rear end portion of the locking bar108is inserted into the outer peripheral locking hole104. At this time, the locking bar108is disposed so as to straddle the boundary between the outer peripheral locking hole104and the storage hole106, so the locking bar108restrains the sleeve member22in the standby position. Further, when the plunger member42that has moved to the actuated position returns to the standby position, as shown inFIG. 1, the locking bar108is moved towards the inner peripheral side by the energizing force of the spring112such that the distal end portion of the locking bar108is inserted into the inner peripheral locking hole102.

Further, in a state where the irregular key12I whose shape is different from that of the regular key12R is inserted into the key hole48and the plunger member42is coupled to the sleeve member22by the tumbler plates66and68, as shown inFIG. 3, the locking bar108moves in the axial direction integrally with the sleeve member22and the plunger member42while being held in the storage hole106and the inner peripheral locking hole102.

Next, the action of the lock device10according to this configuration will be described.

When the user inserts the irregular key12I whose shape is different from that of the regular key12R into the key hole48shown inFIG. 1A, the tumbler plates66and68move to positions corresponding to the upper engaged portions58and the lower engaged portions60of the irregular key12I, and the state of engagement between the engaging tongue portions66A and68A of at least one of the tumbler plates66and68and the engaging recessed portions62is maintained (seeFIG. 4AandFIG. 4B), or the projecting portions66B and68B become engaged with the meshing recessed portions74and the state of engagement between the sleeve member22and the plunger member74is maintained.

Moreover, when the user pushes the irregular key12I in the axial direction, as shown inFIG. 3, the plunger member42and the sleeve member22integrally move the stroke D from the standby positions to the actuated positions.

The actuating lever92in the locked position does not swing even when the plunger member42and the sleeve member22integrally reach the actuated positions, so the locked state of the lock mechanism is maintained. Thereafter, when the user stops pushing the irregular key12I, the plunger member42and the sleeve member22are integrally returned to the standby positions by the energizing force of the coil spring32.

On the other hand, when the user inserts the regular key12R into the key hole48shown inFIG. 1A, the tumbler plates66and68move to the regular positions (seeFIG. 5AandFIG. 5B) corresponding to the upper engaged portions58and the lower engaged portions60of the regular key12R, and the state of engagement between the sleeve member22and the plunger member42is released.

Moreover, when the user pushes the regular key12R in the axial direction, as shown inFIG. 2, just the plunger member42moves the stroke D from the standby position to the actuated position in a state where the sleeve member22is restrained in the standby position by the locking bar108whose cam surface116has been pushed out.

When just the plunger member42reaches the actuated position, the actuating lever92swings to the unlocked position, pushes the coupling rod100down, and unlocks the lock mechanism that had been locked. Thus, the open/close member that had been locked by the lock mechanism is unlocked and becomes capable of being opened.

Thereafter, when the uses removes the regular key12R from the plunger member42, the state of engagement between the upper engaged portions58and the lower engaged portions60formed on the regular key12R and the key insertion holes66C and68C disposed in the tumbler plates66and68is maintained, and the plunger member42returns to the standby position integrally with the removal of the regular key12R.

Here, as mentioned before, the attachment pitch P of the tumbler plates66and68is set to be larger than half of the stroke D. Moreover, as shown inFIG. 4A,FIG. 4BandFIG. 6, the engagement positions46are arranged in a staggered manner in the thickness direction of the key.

For this reason, even when the user removes the regular key12R from the key hole48in the actuated position of the plunger member42shown inFIG. 2and the tumbler plates66and68are energized upward by the energizing force of the coil springs72(seeFIG. 4AandFIG. 4B), the engaging tongue portions66A and68A do not engage with other engaging recessed portions62other than the engaging recessed portions62with which they engage when disposed in the standby position. In other words, they do not obstruct the return of the plunger member42to the standby position.

That is, because the attachment pitch P of the tumbler plates66and68is set to be larger than half of the stroke D, the tumbler plates66and68are configured to stop before they reach the engaging recessed portions62disposed on the same axial line even when the plunger42is moved to the actuated position.

When the engagement positions46are not offset in the thickness direction of the key, the engaging tongue portions66A and68A engage with other engaging recessed portions62and obstruct the return of the plunger member42to the standby position, so the attachment pitch P of the tumbler plates66and68must be set to be larger than the stroke D. For that reason, the lock device10must be made long in the axial direction in order to ensure the predetermined stroke D.

However, by staggering the engagement positions46in the thickness direction of the key as in the present embodiment, it suffices for the attachment pitch P of the tumbler plates66and68to be set to be larger than half of the stroke D, so that even when the number of the tumbler plates66and68is increased in order to diversify the types of the key12, the length of the plunger member42can be controlled from becoming longer.

Further, the user inserts the key12into the key hole48and pushes the key12along the axial direction of the device; thus, when the key12is the regular key12R, the lock mechanism can be unlocked, and when the key12is the irregular key12I, the lock mechanism can be maintained in a locked state. Therefore, it is not necessary for rotational torque to be transmitted by the key12during key manipulation by the user in comparison to a rotary lock device where manipulation with respect to a manipulated device is performed by rotating the key after inserting the key into the key insertion hole, and just a load along the axial direction acts on the key12, so the mechanical strength along the turning direction required of the key12can be made sufficiently small.

Further, because the mechanical strength can be made small, it becomes unnecessary for the key12to invariably be manufactured by a high-strength material such as iron or stainless steel, and the key12can be manufactured by a low-strength material whose use as a conventional material had been difficult, such as plastic, paper to which a waterproof treatment has been administered, an aluminum alloy, or a magnesium alloy, for example. Further, even when the thickness of the key12is made significantly thinner in comparison to that of a conventional key, problems such as deformation do not arise.

Further, even when the irregular key12I including a driver or the like is inserted into the key hole48and pushed to the actuated position, the lock mechanism does not become unlocked simply by the plunger member42and the sleeve member22integrally moving from the standby positions to the actuated positions. Moreover, unreasonable force does not act on the configural parts such as the case member14, the sleeve member22, the plunger member42, and the tumbler plates66and68disposed in these, so damage to these configural parts can be effectively prevented.

Next, a second embodiment of the lock device10of the present invention will be described in accordance withFIG. 9AandFIG. 9B.

It will be noted that the same reference numerals will be given to members that are the same as those in the first embodiment, and that description of those same members will be omitted. As shown inFIG. 9AandFIG. 9B, in this embodiment, in contrast to the first embodiment, not only are the engaging tongue portions66A and68A disposed on the upper ends of the tumbler plates66and68, but engaging tongue portions80A and82A are also disposed on the lower ends of tumbler plates80and82.

Specifically, the tumbler plates66disposed with the engaging tongue portions66A on one side of their upper ends (seeFIG. 4A) are disposed inside the tumbler storage chambers120and128, the tumbler plates68disposed with the engaging tongue portions68A on the other side of their upper ends (seeFIG. 4B) are disposed inside the tumbler storage chambers122and130, a tumbler plate80disposed with the engaging tongue portion80A on one side of its lower end (seeFIG. 9A) is disposed inside the tumbler storage chamber124, and the tumbler plate82disposed with the engaging tongue portion82A on the other side of its lower end is disposed inside the tumbler storage chamber126(seeFIG. 9B).

In this manner, by disposing the engagement positions46configured by the engaging tongue portions80A and82A and the engaging recessed portions62also on the lower side of the plunger member42, the number of key codes can be increased.