# Patent

## Title
Mechanical key code verification system

## Abstract

A mechanical key code verification system including a mechanical key and a lock apparatus into which the mechanical key is insertable. The mechanical key includes a key body and a key code pattern including a plurality of recessed portions and a plurality of non-recessed portions formed on the at least one plane of the key body, the key code pattern having line symmetry.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2008-006056, filed on Jan. 15, 2008, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a mechanical key code verification system for use with a mechanical key having a key code pattern of recessed portions and non-recessed portions and including a lock apparatus that mechanically verifies the key code pattern.
In the prior art, various types of key systems are used to prevent unauthorized use of articles, doors, and the like by a third person. A typical key system uses a key that includes a grip and an elongated key plate (also referred to as a key blade), which has an engraved key code. Insertion of the key plate into a cylinder of a lock apparatus aligns the engraved key code with a plurality of disk tumblers (small steel pieces), which are biased by springs arranged in the cylinder. Rotation of the cylinder with the key is permitted when the key code of the key plate matches a key shape formed by the disk tumblers. In such a case, the opening and closing of the lock apparatus is enabled. Japanese Utility Model Registration No. 3090369 (patent document 1) and Japanese Laid-Open Patent Publication No. 2004-76375 (patent document 2) describe examples of a card key system using a card key. FIG. 10 illustrates a card key system 81. The card key system 81 includes a card key 82 and a lock apparatus 86. The card key 82 has a key code pattern 83 including a plurality of holes 84 arranged in accordance with a key code of the card key 82.
FIG. 11 illustrates the lock apparatus 86 (also referred to as a fixed component) in a state in which the card key 82 is not inserted therein. The lock apparatus 86 includes a supporting member 90 and a movable member 88 supported by the supporting member 90. The movable member 88 moves relative to the supporting member 90 when the card key 82 is inserted into the lock apparatus 86 to perform a key operation. The movable member 88 and the supporting member 90 may be referred to as the movable side and fixed side, respectively. A plurality of pin tumblers 87 are arranged so as to extend into the movable member 88 and the supporting member 90. Each pin tumbler 87 includes a lock pin 89 accommodated in the movable member 88 and a plunger pin 91 accommodated in the supporting member 90. The plunger pin 91 is biased towards the lock pin 89 by a tumbler spring 92. The plurality of pin tumblers 87 include first pin tumblers 87a and second pin tumblers 87b. In each first pin tumbler 87a, the plunger pin 91 is engaged with both of the movable member 88 and the supporting member 90 when the card key 82 is not inserted into the lock apparatus 86. In each second pin tumbler 87b, a shear line between the lock pin 89 and the plunger pin 91 is aligned with a shear line between the movable member 88 and the supporting member 90 when the card key 82 is not inserted into the lock apparatus 86.
As illustrated in FIG. 13, when the proper card key 82 is inserted into the lock apparatus 86, the shear line between the lock pin 89 and the plunger pin 91 is aligned with the shear line between the movable member 88 and the supporting member 90 in each of the pin tumblers 87 (first pin tumblers 87a and second pin tumblers 87b). This permits movement of the movable member 88 with respect to the supporting member 90 so that closing and opening of the lock apparatus 86 becomes possible.
As illustrated in FIG. 12, if the card key 82 inserted into the lock apparatus 86 is an improper key, the holes 84 of the card key 82 may be aligned with the first pin tumblers 87a, and the second pin tumblers 87b may be aligned with non-hold portions 85 of the card key 82. In such a first pin tumbler 87a, the plunger pin 91 may be lowered by the amount the distal end of the lock pin 89 is accommodated in the hole 84. Thus, the plunger pin 91 would be engaged with both of the movable member 88 and the supporting member 90. In such a second pin tumbler 87b, the distal end of the lock pin 89 may be lifted by the non-hold portion 85 of the card key 82. Thus, the lock pin 89 would be engaged with both of the movable member 88 and the supporting member 90. As a result, the pin tumblers 87 prohibit movement of the movable member 88 relative to the supporting member 90. Thus, the opening and closing of the lock apparatus 86 cannot be performed with an improper key.

    [Patent Document 1] Japanese Utility Model Registration No. 3090369
    [Patent Document 2] Japanese Laid-Open Patent Publication No. 2004-76375


SUMMARY OF THE INVENTION
Due to the positions of the holes 84 in the key code pattern 83, in order to verify the card key 82, the same side of the card key 82 must always be inserted first into the lock apparatus 86 with the card key 82 facing the same direction. Otherwise, the card key 82 cannot be verified even if it is a proper key, and the lock apparatus 86 thus cannot be opened or closed. More specifically, if the card key 82 is inserted into the lock apparatus 86 in a reversed state or if the card key 82 is inserted sideways into the lock apparatus 86, the card key 82 cannot be verified.
The present invention reduces the number of times the direction in which a card key is facing must be corrected when inserting the card key into a lock apparatus.
One aspect of the present invention is a mechanical key code verification system including a mechanical key and a lock apparatus into which the mechanical key is insertable. The mechanical key includes a key body having at least one plane. A key code pattern including a plurality of recessed portions and a plurality of non-recessed portions is formed on the at least one plane of the key body. The key code pattern has line symmetry.
In one embodiment, the plurality of recessed portions and plurality of non-recessed portions in the key code pattern are arranged to be symmetric about a bisector of a right angle corner portion of the mechanical key.
In one embodiment, the mechanical key code verification system is a mechanical operation type key system arranged in a vehicle including an electronic key system which verifies an electronic key code transmitted through wireless communication from an electronic key; and the mechanical key is an emergency key for the electronic key system.
In one embodiment, the mechanical key is a card key.
In one embodiment, the plurality of recessed portions in the key code pattern are through holes.
In one embodiment, the lock apparatus includes a support member; and a movable member which is movable relative to the support member. Each of the tumblers is a pin tumbler including a first lock pin arranged in the movable member and a second lock pin arranged in the support member, in which mechanical verification of the key code pattern is established thereby enabling the movable member to be movable when a shear line between the first lock pins and the second lock pins of the plurality of pin tumblers in the lock apparatus is aligned with a shear line between the movable member and the support member in the lock apparatus.
In one embodiment, the mechanical key is a card key including a plurality of corner portions. The plurality of recessed portions of the key code pattern are formed in the vicinity of single one of the plurality of corner portions. The vicinities of the other corner portions are flat.
Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.



BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a block diagram of a key operation-free system;
FIG. 2 is a perspective view showing a lock apparatus and a card key for a mechanical operation type door lock system;
FIG. 3 is a plan view showing the positions of holes in the key code pattern of the card key and the layout of lock pins in the lock apparatus;
FIG. 4 is a cross-sectional view of the lock apparatus without the card key;
FIG. 5(a) is a cross-sectional view of the lock apparatus together with a proper card key, and FIGS. 5(b) and 5(c) are partial enlarged views of the lock apparatus together with an improper card key;
FIG. 6 is a cross-sectional view of the lock apparatus when opened by the card key;
FIG. 7 is a cross-sectional view of the lock apparatus when closed by the card key;
FIG. 8 is a diagram showing how the card key is used;
FIG. 9 is a diagram showing how to use a compact card key, which is cut out from a card key;
FIG. 10 is a plan view showing a lock apparatus before insertion of a card key in the prior art;
FIG. 11 is a cross-sectional view of the lock apparatus shown in FIG. 10;
FIG. 12 is a cross-sectional view of the lock apparatus with a proper card key in the prior art; and
FIG. 13 is a cross-sectional view of the lock apparatus with an improper card key in the prior art.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of a mechanical key code verification system according to the present invention will now be discussed with reference to FIGS. 1 to 9.
As illustrated in FIG. 1, a vehicle 1 incorporates a key operation-free system 2 that performs vehicle operations including the locking and unlocking of the doors and the starting and stopping of the engine without physically operating a vehicle key. The key operation-free system 2 uses a vehicle key (hereinafter referred to as portable device 3) that transmits a unique ID code (key code) through wireless communication. In the key operation-free system 2, the vehicle 1 transmits a request signal Srq requesting the ID code. The portable device 3 returns an ID signal Sid including the ID code to the vehicle 1 through narrow-band wireless communication in response to the request signal Srq. If the ID code of the portable device 3 matches an ID code of the vehicle 1, the key operation-free system 2 enables the locking and unlocking of the door and the starting and stopping of the engine. The key operation-free system 2 is one example of an electronic key system, and the portable device 3 is one example of an electronic key.
The key operation-free system 2 incorporates a smart entry system 4 that locks and unlocks the doors without any physical operation of the vehicle key. The smart entry system 4 will now be described. The vehicle 1 includes a verification ECU 5 for verifying the ID code of the portable device 3 in the ID signal Sid received through narrow-band wireless communication. The verification ECU 5 is connected to a vehicle exterior LF transmitter 6, a vehicle interior LF transmitter 7, and an RF receiver 8. The vehicle exterior LF transmitter 6 is arranged in each door of the vehicle 1 to transmit a long frequency (LF band) signal out of the vehicle through wireless communication. The vehicle interior LF transmitter 7 is arranged in the vehicle (e.g., in the floor etc.) to transmit a LF band signal within the vehicle through wireless communication. The RF receiver 8 is arranged in the vehicle (e.g., in the rearview mirror etc.) to receive an RF band signal through wireless communication. The LF transmitters 6 and 7 transmit the request signal Srq through wireless communication. Specifically, the vehicle exterior LF transmitter 6 forms a communication area (vehicle exterior communication area) for the request signal Srq around the vehicle. The vehicle interior LF transmitter 7 forms a communication area (vehicle interior communication area) for the request signal Srq throughout the entire vehicle interior.
The verification ECU 5 is connected to a touch sensor 10 arranged, for example, in a door handle 9 at the outer side of the vehicle (refer to FIG. 2). The touch sensor 10 detects a person touching the door handle 9 when the door is locked to unlock the door. The verification ECU 5 is connected to a lock button 11 arranged in, for example, the door handle 9. The lock button 11 is pushed to lock the unlocked door. The verification ECU 5 is connected to a door ECU 12, which controls the locking and unlocking of the door though an in-vehicle LAN 13. The door ECU 12 locks or unlocks the door by driving a door lock motor 14 in accordance with a command from the verification ECU 5.
The portable device 3 includes a communication control unit 15 for controlling wireless communication that is performed with the vehicle 1. The communication control unit 15 is connected to an LF reception unit 16, which receives an LF band signal, and an RF transmission unit 17, which transmits an RF band signal in accordance with a command from the communication control unit 15. The LF reception unit 16 demodulates an LF band signal, which is received by an LF reception antenna 18 in an LF receiver circuit 19, and provides the demodulated signal to the communication control unit 15 as received data. The RF transmission unit 17 modulates transmission data provided from the communication control unit 15 with an RF transmitter circuit 20, generates the ID signal Sid in the RF band with the unique ID code of the portable device 3, and transmits the ID signal Sid from an RF transmission antenna 21.
When the vehicle 1 is in a parked state (engine stopped and doors locked), the verification ECU 5 intermittently transmits the request signal Srq in the LF band to the vehicle exterior LF transmitter 6 and forms the vehicle exterior communication area around the vehicle. When the portable device 3 enters the vehicle exterior communication area and receives the request signal Srq with the LF reception unit 16, the portable device 3 transmits the ID signal Sid containing the ID code registered in a memory 22 to the RF transmission unit 17 as the RF band wireless signal in response to the request signal Srq. In the verification ECU 5, the ID code of the portable device 3 contained in the ID signal Sid and received by the RF receiver 8 is verified with the ID code registered in a memory 23 (vehicle exterior verification). When the vehicle exterior verification is completed, the verification ECU 5 sets a vehicle exterior verification flag in the memory 23 over a fixed time period and activates the touch sensor 10 in a standby state during that time period. When the activated touch sensor 10 detects that the vehicle exterior door handle has been touched, the door ECU 12 unlocks the locked door by generating rotation with the door lock motor 14 in one direction.
In a state in which the vehicle 1 is not moving (engine stopped and door unlocked), the verification ECU 5 transmits the request signal Srq to the vehicle exterior LF transmitter 6 when detecting that the lock button 11 has been pushed. The verification ECU 5 performs the vehicle exterior verification on the ID signal Sid returned from the portable device 3 in response to the request signal Srq. The verification ECU 5 provides a door lock request to the door ECU 12 when the vehicle exterior verification is completed. The door ECU 12 locks the unlocked door by generating rotation with the door lock motor 14 in the other direction in response to the door lock request.
The key operation-free system 2 includes a one-push engine start system 24 enabling the starting and stopping of the engine by just operating a vehicle switch. Physical operation of the vehicle key is not necessary. The one-push engine start system 24 will now be described. The vehicle 1 includes an engine ECU 26 that executes ignition control and fuel injection control on an engine 25, a gearshift ECU 27 that controls automatic transmission according to the operation of a gearshift lever, and a power supply ECU 28 that executes power supply management for in-vehicle electrical components. The ECUs 26 to 28 are connected to various ECUs including the verification ECU 5 through the in-vehicle LAN 13.
An engine switch 29, which is operated when switching the power supply state of the vehicle 1, is arranged near the driver's seat in the vehicle 1. The engine switch 29 is of a push-operation type and includes a switch portion 29a that is pushed. The engine switch 29 is connected to the power supply ECU 28 by a harness. The engine switch 29 has an engine starting and stopping operation function, which switches the engine 25 to a started state or a stopped state, and a power supply transition operation function, which switches the power supply state of the vehicle 1 to an OFF state, an ACC ON state, or an IG ON state.
The power supply ECU 28 is connected to a vehicle speed sensor 30, which detects the travel speed of the vehicle 1, and a brake sensor 31, which detects the depression amount of the brake pedal. The power supply ECU 28 recognizes the current traveling speed of the vehicle 1, which is based on the vehicle speed information from the vehicle speed sensor 30, and determines depression of the brake pedal, which is based on the pedal depression amount information from the brake sensor 31. The power supply ECU 28 is connected to an ACC relay 32, which is connected to various in-vehicle accessories, an IG relay 33, which is connected to the engine ECU 26, and a starter relay 34, which is connected to a starter motor of the engine 25.
After the vehicle exterior verification is completed and the door is unlocked, the verification ECU 5 recognizes via a courtesy switch 35 that the driver is entering the vehicle as the door opens. The verification ECU 5 forms the vehicle interior communication area in the entire vehicle interior by transmitting the request signal Srq to the vehicle interior LF transmitter 7. When receiving the ID signal Sid in response from the portable device 3, which is located in the vehicle interior communication area, with the RE receiver 8 (vehicle interior verification), the verification ECU 5 verifies the ID code of the portable device 3 contained in the ID signal Sid with the ID code registered in the verification ECU 5. The verification ECU 5 sets a vehicle interior verification completion flag in the memory 23 when the vehicle interior verification is completed.
When the driver pushes the engine switch 29 to switch the power supply state of the vehicle 1, the power supply ECU 28 first checks the verification ECU 5 and determines whether the vehicle interior verification has been completed. The power supply ECU 28 recognizes that the vehicle interior verification has been completed when notified by the verification ECU 5 that the vehicle interior verification has been completed. When notified by the verification ECU 5 that the vehicle interior verification ha not been satisfied, the power supply ECU 28 instructs the verification ECU 5 to re-execute the vehicle interior verification and re-check whether the vehicle interior verification has been completed. The power supply ECU 28 continues to determine that the vehicle interior verification has not been completed even after the verification ECU 5 re-executes the vehicle interior verification unless notified by the verification ECU 5 that the vehicle interior verification has been completed.
When the engine switch 29 is pushed in a state in which the brake pedal is depressed and the engine 25 is stopped, the power supply ECU 28 activates the three relays 32 to 34 to start the engine 25 as long as the vehicle interior verification is satisfied and then outputs an activation signal to the engine ECU 26. When receiving the activation signal, the engine ECU 26 checks the result of the vehicle interior verification and then checks whether the verification ECU 5 and the engine ECU 26 are a proper pair by performing pairing through encryption communication. If the two conditions are satisfied, the engine ECU 26 initiates the ignition control and the fuel injection control to start the engine 25. In a state in which the vehicle 1 stops moving (vehicle speed “0”) and the engine switch 29 is pushed while the engine 25 is still running, the power supply ECU 28 deactivates all of the three relays 32 to 34 to stop the engine 25.
When the engine switch 29 is pushed but the brake pedal is not depressed in a situation in which the conditions are met of the engine 25 being stopped, the vehicle interior verification being completed, and the gearshift lever being at the P range position, the power supply ECU 28 sequentially shifts the power supply state in a manner of OFF state→ACC ON state→IG ON state→OFF state whenever the engine switch 29 is pushed. In the above situation, the power supply state of the vehicle 1 is switched from the OFF state to the ACC state when the engine switch 29 is pushed once. From this state, the power supply state of the vehicle 1 is switched to the IG ON state when the engine switch 29 is pushed again once. From this state, the power supply state of the vehicle 1 returns to the OFF state when the engine switch 29 is pushed again once.
A mechanical key code verification system, or mechanical operation type door lock system 36, illustrated in FIG. 2 will now be discussed. The mechanical operation type door lock system 36 is advantageous when a physical key operation with a mechanical key becomes necessary to lock or unlock the doors. Since the smart entry system 4 (key operation-free system 2) is of an electrical type, a door cannot be locked or unlocked by the smart entry system 4 if the smart entry system 4 fails to function or if battery drainage occurs in the portable device 3. The mechanical operation type door lock system 36 is used to enable the locking and unlocking of the doors under such situation.
The mechanical operation type door lock system 36 includes a lock apparatus 37, which is attached to an outer wall of the vehicle door (driver's seat door) 1a, and a mechanical key 38. The mechanical key 38 is inserted into the lock apparatus 37 and physically operated to open (unlock state) or close (lock state) the lock apparatus 37. In the preferred embodiment, the mechanical key 38 is of a card type (flat plate-shape) and is thus also referred to as the card key 38. The mechanical operation type door lock system 36 may be referred to as a card key type door lock system. In a state in which the proper card key 38 is inserted into a key hole 39 of the lock apparatus 37, the door is locked by moving the card key 38 from the initial position in a first direction (e.g., upward direction). In a state in which the proper card key 38 is inserted into the key hole 39 of the lock apparatus 37, the door is unlocked by moving the card key 38 from the initial position in a second direction (e.g., downward direction).
The mechanical operation type door lock system 36 is used during an emergency such as when the smart entry system 4 fails to function or when battery drainage occurs in the portable device 3. The card key 38 is used as an emergency key during such an emergency. The card key 38 is flat and has a size similar to that of a typical credit card. Thus, the card key 38 can be carried in a wallet, a card case, and the like in the same manner as credit cards.
As illustrated in FIG. 2, a key body 40 (also referred to as case portion) of the card key 38 has a key code pattern 41 defined on at least one surface, such as a main surface, of the card key 38. One or more recessed portions and one or more non-recessed portions are formed in the key code pattern 41. The array (pattern) of the holes 42 and the non-hole portions 43 in the key code pattern 41 expresses the key code for the card key 38 of the mechanical operation type door lock system 36.
The recessed portions in the key code pattern 41 are holes 42 arranged in the main surface of the key body 40. The non-recessed portions are non-hole portions 43 defined in the main surface of the key body 40 at portions that do not include the holes 42. The key code pattern 41 is arranged near the distal end of the key body 40. Each hole 42 can be a round through hole, such as a punched hole, extending through the key body 40 but it does not necessary have to be round. The non-hole portions 43 may be projections. The holes 42 are one example of recessed portions. The non-hole portions 43 are one example of non-recessed portions.
Referring to FIG. 3, the key code pattern has line symmetry. More specifically, the holes 42 and non-hole portions 43 of the key code pattern 41 are arranged to be symmetric about a code pattern center line La, which extends across a corner portion 38a of the card key 38 in one example, the card key 38 is rectangular and includes a first side 40a and a second side 40b. The first side 40a has a dimension corresponding to the width of the card key 38. The second side 40b has a dimension corresponding to the length of the card key 38. The corner portion 38a is located between the first side 40a and the second side 40b. The angle of the first side 40a relative to the second side 40b is, for example, ninety degrees. The code pattern center line La bisects the corner portion 38a. In other words, the angle of the code pattern center line La relative to the first side 40a is, for example, forty-five degrees, and the angle of the code pattern center line La relative to the second side 40b is, for example, forty-five degrees. The corner portion 38a is referred to as a right angle corner portion. The code pattern center line La is referred to as a bisector of the right angle corner portion.
Referring to FIGS. 4 to 7, the lock apparatus 37 includes a slider case 44. The slider case 44 is the body portion of the lock apparatus 37 and is box-shaped. The key hole 39 (see FIG. 2) is formed in a side wall of the slider case 44. The slider case 44 is attached to the outer wall of the vehicle door 1a. A slider 45 is accommodated in an accommodating space 44a of the slider case 44 so as to be movable (linearly movable) relative to the slider case 44. The slider 45 is formed by a plate. The slider 45 is movable in an R1 direction (FIG. 6) and an R2 direction (FIG. 7) in the accommodating space 44a of the slider case 44. The slider case 44 is one example of a support member, and the slider 45 is one example of a movable member. The slider case 44 may be referred to as a fixed side of the lock apparatus 37, and the slider 45 may be referred to as a movable side of the lock apparatus 37.
The card key 38 when inserted into the key hole 39 is received in a key slot 45a, which is formed in the slider 45. The key slot 45a has dimensions that are slightly greater than the width and thickness of the card key 38 to allow the insertion of different sizes of the card key 38. Although not shown in the drawings, the slider 45 includes a positioning mechanism that positions the card key 38 at a key verification position (pin alignment position) regardless of the size of the card key 38. The positioning mechanism may include a tab, which is formed on the side of the card key 38 that is first inserted into the lock apparatus 37, and a notch, which is formed in the inner portion of the slider 45 to be engageable with the tab of the card key 38.
As shown in FIGS. 4 to 7, pin tumblers 46 are arranged between the slider case 44 and the slider 45 to fix the slider 45 to the slider case 44 and disable the locking and unlocking operation when the proper card key 38 is not used. The plurality of pin tumblers 46 each face one of the holes 42 or the non-hole portions 43 when the card key 38 is inserted into the lock apparatus 37. As shown in FIG. 3, the pin tumblers 46 are arranged to be symmetric about a lock apparatus center line Lb, which corresponds to the code pattern center line La. The quantity of the pin tumblers 46 is the same as the total quantity of the holes 42 and non-hole portions 43 in the card key 38. For example, there are nineteen pin tumblers 46 when there are eleven holes 42 and eight non-hole portions 43. The pin tumblers 46 are one example of tumblers.
Each pin tumbler 46 includes a plunger pin 48 (second lock pin), which is movably accommodated in a case side accommodation hole 47 formed in the slider case 44, and a lock pin 50 (first lock pin), which is movably accommodated in a slider side accommodation hole 49 formed in the slider 45. The pin tumbler 46 is constantly biased toward the slider 45 by a tumbler spring 51 accommodated in the case side accommodation hole 47. The lock pin 50 is longer than the plunger pin 48. The lock pin 50 has a distal end formed by a round surface, for example, a semispherical surface. The tumbler spring 51 is one example of a biasing member.
The pin tumbler 46 includes one or more first pin tumblers 46a, in which the lock pin 50 is short, and one or more second pin tumblers 46b, in which the lock pin 50 is long.
The first pin tumblers 46a are located at positions corresponding to the non-hole portions 43 of the proper card key 38 that is inserted into the lock apparatus 37. When the card key 38 is not inserted into the lock apparatus 37 as illustrated in the state of FIG. 4 or when the first pin tumblers 46a are forced into the holes 42 of an improper card key 38 as illustrated in the state of FIG. 5(b), the plunger pin 48 of each first pin tumbler 46a engages both the slider case 44 and the slider 45 over a constant engagement length K (pin tumbler locking state) and restricts movement of the slider 45. When the proper card key 38 is inserted into the lock apparatus 37 as illustrated in the state of FIG. 5(a), the first pin tumblers 46a are moved upward by an amount corresponding to the engagement length K against the biasing force of the corresponding tumbler springs 51 by the non-hole portions 43 of the card key 38. The shear line between the plunger pin 48 and the lock pin 50 of each first pin tumbler 46a (shear line between the two components of the plunger pin 48) becomes aligned with the shear line between the slider case 44 and the slider 45 (slide surface of the slider 45) (pin tumbler unlocking state). The first pin tumblers 46a in the pin tumbler unlocking state do not function to restrict movement of the slider 45.
The second pin tumblers 46b are located at positions corresponding to the holes 42 of the proper card key 38 that is inserted into the lock apparatus 37. When the card key 38 is not inserted into the lock apparatus 37 as illustrated in the state of FIG. 4 or when the second pin tumblers 46b are forced into the holes 42 of the proper card key 38 as illustrated in FIG. 5(a), the shear line between the plunger pin 48 and the lock pin 50 of each second pin tumbler 46b is aligned with the shear line between the slider case 44 and the slider 45 (pin tumbler unlocking state) The second pin tumblers 46b in the pin tumbler unlocking state do not function to restrict movement of the slider 45. When an improper key is inserted into the lock apparatus 37 as illustrated in the state of FIG. 5(c), the second pin tumblers 46b are forced upward against the biasing force of the corresponding tumbler springs 51 by the non-hole portions 43. The second pin tumblers 46b engage both the slider case 44 and the slider 45 (pin tumbler locking state) and restrict movement of the slider 45. The lift amount of each second pin tumbler 46b is the engagement length K of the lock pin 50 in each second pin tumbler 46b. 
The slider 45 is connected to a dead bolt (not shown) or the door lock member of the vehicle door 1a by a transmission mechanism (not shown). The transmission mechanism transmits and converts the movement of the slider 45 to the mechanical opening and closing of the dead bolt. Referring to FIGS. 6 and 7, when the card key 38 is inserted into the lock apparatus 37, the slider 45 becomes movable in two directions from a neutral position. When the slider 45 is moved in one direction (direction of arrow R1 in FIG. 6) from the neutral position, the transmission mechanism converts the movement of the slider 45 to a projection operation of the dead bolt to unlock the vehicle door 1a. When the slider 45 is moved in the other direction (direction of arrow R2 in FIG. 7) from the neutral position, the transmission mechanism converts the movement to a retraction operation of the dead bolt to lock the vehicle door 1a. 
The operation of the mechanical operation type door lock system 36 will now be discussed.
When a driver tries to enter the vehicle 1, which is in a parked state (engine stopped, door locked state), if the key operation-free system 2 fails to function or if battery drainage occurs in the portable device 3, the doors cannot be unlocked with the key operation-free system 2. In such a case, the driver unlocks the vehicle door 1a with the mechanical operation type door lock system 36. The driver may carry the card key 38 of the mechanical operation type door lock system 36 in a wallet, a card case, or the like. The driver inserts the card key 38 into the key hole 39 of the lock apparatus 37. The slider 45 is at the neutral position when the card key 38 is inserted into the lock apparatus 37.
As illustrated in the state of FIG. 4, when the card key 38 is not inserted into the lock apparatus 37, the second pin tumblers 46b are in the pin tumbler unlocking state. However, the first pin tumblers 46a are in the pin tumbler locking state. The first pin tumblers 46a restrict movement of the slider 45 relative to the slider case 44. Thus, the slider 45 cannot be moved even when a person inserts his or her fingers into the key hole 39 of the lock apparatus 37 to forcibly move the slider 45. In this manner, unauthorized opening and closing of the lock apparatus 37 is prevented.
When inserting the card key 38 into the key hole 39, the edge of the card key 38 enters the gap below the distal ends of the pin tumblers 46 and thereby lifts the pin tumbler 46. When the card key 38 is inserted into the innermost portion of the key hole 39, if the card key 38 is a proper key, the non-hole portions 43 of the card key 38 are located at positions corresponding to the first pin tumblers 46a, and the holes 42 of the card key 38 are located at positions corresponding to the second pin tumblers 46b, as shown in the state of FIG. 5(a).
If the card key 38 is a proper key, each first pin tumbler 46a is forced upward by a distance corresponding to the sum of the plate thickness of the card key 38 and the depth of the pin accommodation recess 56 by the corresponding non-hole portion 43 of the card key 38 against the biasing force of the tumbler spring 51. The shear line between the plunger pin 48 and the lock pin 50 of the first pin tumbler 46a is aligned with the shear line between the slider case 44 and the slider 45 (pin tumbler unlocking state). Each second pin tumbler 46b is fitted into the associated hole 42 of the card key 38 and thus forced towards the slider 45 by the tumbler spring 51, and the shear line between the plunger pin 48 and the lock pin 50 of the second pin tumbler 46b is aligned with the shear line between the slider case 44 and the slider 45 (pin tumbler unlocking state).
The first pin tumblers 46a and the second pin tumblers 46b are both in the pin tumbler unlocking state. Thus, the lock apparatus 37 is in a slider movable state in which the slider 45 is movable relative to the slider case 44. The slider 45 can be moved from the neutral position with the card key 38 when the lock apparatus 37 is in the slider movable state. Therefore, if the proper key 38 is inserted into the lock apparatus 37 and moved in one direction (direction of arrow R1 in FIG. 6) to move the slider 45 in that direction (as shown in the state of FIG. 6) and open the lock apparatus 37, such movement is transmitted to the dead bolt by the transmission mechanism. This retracts the dead bolt from a projected state and unlocks the vehicle door 1a. 
The plunger pin 48 and the lock pin 50 of each of the pin tumblers 46 must be facing toward each other to enable upward and downward movements of the pin tumblers 46. That is, the card key 38 cannot be removed from the lock apparatus 37 unless the plunger pin 48 and the lock pin 50 of each pin tumbler 46 are facing each other. Therefore, after unlocking the vehicle door 1a, the driver returns the card key 38 to the initial position by moving the slider 45 to the neutral position to remove the card key 38 from the lock apparatus 37. The driver then pulls out the card key 38 from the lock apparatus 37 and enters the vehicle while holding the card key 38. The driver performs card key operations in this manner to enter the vehicle.
When locking the vehicle door 1a with the mechanical operation type door lock system 36, the proper card key 38 is inserted into the lock apparatus 37 in which the slider 45 is located at the neutral position. Then, the driver moves the card key 38 in the other direction (direction of arrow R2 of FIG. 7) to move the slider 45 in the other direction (state illustrated in FIG. 7). In this case, the movement of the slider 45 is transmitted to the dead bolt by the transmission mechanism. This projects the dead bolt from the retracted state to lock the vehicle door 1a. When removing the card key 38 from the lock apparatus 37 after locking the vehicle door 1a, the driver returns the card key 38 to the initial position by moving the slider 45 to the neutral position. Then, the driver pulls the card key 38 out from the lock apparatus 37 in the same manner as when unlocking the vehicle door 1a with the lock apparatus 37.
The operation of the mechanical operation type door lock system 36, especially, the card key 38 will now be discussed.
The card key 38 includes a widthwise direction (the direction of arrow Z1 in FIG. 8) and a lengthwise direction (the direction of arrow Z1 in FIG. 8). The key code pattern 41 is symmetric on opposite sides of the code pattern center line La, which bisects the corner portion 38a. Due to the symmetry of the key code pattern 41, the card key 38 may be inserted into the lock apparatus 37 in two states. FIG. 8 shows the first insertion state and the second insertion state. In the first insertion state, the first side 40a of the card key 38 is first inserted into the lock apparatus 37. In the second insertion state, the second side 40b of the card key 38 is first inserted into the lock apparatus 37. From the first insertion state, the card key 38 is rotated by 90 degrees within the same plane and then obverted (turned upside down) to shift to the second insertion state. Therefore, the card key 38 when in the first insertion state is rotated by 180 degrees about the code pattern center line La to shift to the second insertion state.
For example, when the user takes out the card key 38 from a wallet or the like and holds the card key 38 with the first side 40a or the second side 40b facing forward, the user does not have to correct the direction in which the card key 38 is being held to open or close the lock apparatus 37. That is, the user just inserts the first side 40a or second side 40b first into the lock apparatus 37. This reduces the number of times the direction in which the card key 38 is facing must be corrected when inserting the card key 38 into the lock apparatus 37.
Further, since the key code pattern 41 is line-symmetric about the code pattern center line La, the card key 38 may be cut to reduce the size of the card key 38. FIG. 9 shows a normal or regular-size card key 52, which is identical to the card key 38 shown in FIGS. 2, 3, and 8. The regular-size card key 52 includes a perforation Lx, which is parallel to the first side 40a. By cutting the regular-size 1 card key 52 along the perforation Lx, a compact card key 53, which includes the key code pattern 41 can be obtained. If the first side 40a is facing forward, to insert the second side 40b first into the lock apparatus 37, the compact card key 53 may be rotated by 90 degrees within the same plane and then obverted.
For example, a user who wishes to use the card key 38 with the regular size does not cut the card key 38 and thus uses the regular-size card key 52. A user who wishes to reduce the size of the card key 38 cuts the regular-size card key 52 along the perforation Lx and uses the compact card key 53, which includes the key code pattern 41. In this manner, the size of the card key 38 may be changed in accordance with the user's preference. Further, the regular-size card key 52 can easily be changed to the compact card key 53 just by performing a single cutting operation.
The preferred embodiment has the advantages described below.
(1) The key code pattern 41 of the card key 38 includes the holes 42 and the non-hole portions 43, which are arranged to be symmetric about the code pattern center line La that bisects the corner portion 38a of the card key 38. Thus, the card key 38 can be inserted into the lock apparatus 37 in a plurality of insertion states. This reduces the number of times the direction in which the card key 38 is facing must be corrected when inserting the card key 38 into the lock apparatus 37.
(2) The key code pattern 41 of the card key 38 (regular-size card key 52) is symmetric about the code pattern center line La, which bisects the right angle corner portion 38a of the card key 38 (regular-size card key 52). Thus, the compact card key 53 can be obtained from the regular-size card key 52 by just cutting the regular-size card key 52 once. The size of the card key may be changed in accordance with the user's preference. This improves convenience. Further, the regular-size card key 52 can easily be cut.
(3) The compact card key 53 is smaller in size than the regular-size card key 52. Thus, the compact card key 53 may be accommodated in a smaller space. This is advantageous for an emergency key.
(4) The card key 38 functions as an emergency key for the key operation-free system 2, and an emergency mechanical key does not need to be accommodated in the portable device 3. The emergency mechanical key can thus be omitted from the portable device 3, and the portable device 3 can be further miniaturized by the omission of the emergency mechanical key.
(5) The lock apparatus 37 of the mechanical operation type door lock system 36 is of a pin tumbler type that includes two types of pin members and is thus simple.
(6) The card key 38 is thin and card-shaped. Thus, the card key 38 may be accommodated in a small space in a wallet or the like. Thus, the card key 38 may be easily carried.
(7) The card key 38 includes in the key code pattern 41 a key code expressed by the existence and non-existence of holes 42 formed in a card material (plate material). The holes 42 may be replaced with recesses having closed bottoms when forming the key code in the card key 38. However, such a card key 38 would have to be thicker to provide sufficient depths for bottomed recess. Such a thick card key is not preferable. The card key 38 of the preferred embodiment is thin since the holes 42 extend through the card key 38.
It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the present invention may be embodied in the following forms.
As long as the key code pattern 41 of the card key 38 is line-symmetric, there is no need for the center line La to extend across the corner portion 38a of the card key 38 or be diagonal to the card key 38. For example, a line extending perpendicular to the first side 40a or second side 40b of the card key 38 may be used as the center line La, with the key code pattern 41 being symmetric about the center line La. As long as the key code pattern 41 is symmetric, the center line La, to which the key code pattern 41 would be symmetric, may extend in any direction.
The quantity of the holes 42, the quantity of the non-hole portions 43, the ratio between the holes 42 and the non-hole portions 43, and the total quantity of the holes 42 and non-hole portions 43 are not limited in any manner and may be changed. Further, the hole distance and hole diameter do not have to be set as fixed values.
The card key 38 does not have to be shaped like a credit card as described above. For example, the card key 38 may be shaped so as to include a wireless communication mechanism (RFID tag) enabling identification of an individual or electronic payment.
The shape of the holes 42 in the key code pattern 41 is not limited in any manner and does not have to be round. For example, the holes may be oblong, tetragonal, or triangular. Further, the holes 42 are not limited to round holes having the same dimensions and may include small round holes and large round holes. Alternatively, the holes 42 may include round holes and holes having other shapes.
The mechanical key of the mechanical operation type door lock system 36 is not limited to the card key 38, which is a very thin plate shaped identically to a credit card, and may be a rather thick plate such as a memory card. Further, the mechanical key does not have to be tetragonal (rectangular) and may have any shape. For example, the mechanical key may be round.
It is preferable that the holes 42 that form the key code pattern 41 extend through the card key 38. However, recesses that do not extend through the card key 38 may be used in lieu of the holes 42.
The lock apparatus 37 is not limited to a structure for manually moving the slider 45 with the card key 38. An electrical structure for detecting the pin tumbler unlocking state of all the pin tumblers with a sensor and moving the slider 45 with power from the motor and the like may be adopted.
The lock apparatus 37 is not limited to a slide type in which the movable member (slider 45) linearly slides and may be a rotatable type in which the movable member is rotated by a key.
The lock apparatus 37 is not limited to a structure in which the slider 45 moves in two directions from a neutral position to open or close the lock apparatus 37. For example, the lock apparatus 37 may have a structure in which the lock apparatus 37 switches between open and closed states whenever the slider 45 is moved in the same direction from the neutral position.
The biasing member for biasing each pin tumbler 46 is not limited to a spring and may be a rubber material.
The lock apparatus 37 is not limited to a pin tumbler-type including the pin member, and may be a disk tumbler-type in which the tumbler member is plate-shaped.
The activation of the relays 32 to 34 is not limited to electrical management by the power supply ECU 28 and may be a mechanical type in which the relays are switched between activated and deactivated states by the physical operation of a key.
The electronic key system is not limited to a key operation-free system 2 in which the locking and unlocking of the door and the starting and stopping of the engine are automatically permitted or executed as long as the driver is carrying the proper portable device 3. A wireless key system in which various operation buttons are formed in the electronic key may be used in which an operation request command and key code are transmitted to the vehicle 1 through wireless communication when such a button is pushed.
The engine starting and stopping system of the vehicle 1 is not limited to a one-push engine start system 24 and may be a mechanical operation engine starting and stopping system in which the mechanical key 38 is inserted into the engine starting and stopping key cylinder and turned to start or stop the engine. In this case, the card key 38 may be used to switch electrical power supplies of the vehicle 1.
The mechanical operation key system using the card key 38 is not necessarily limited to emergency use with the smart entry system 4 and may be used during an emergency of the one-push engine start system 24. The mechanical operation key system using the card key 38 of the preferred embodiment merely needs to be adopted in at least one of the smart entry system 4 or the one-push engine start system 24.
The key operation-free system 2 may be an immobilizer system that performs wireless ID verification with a communication tag component incorporated in the portable device 3. In the immobilizer system, the portable device 3 is held near a transponder key coil, which is arranged in a vehicle. This causes the coil to transmit drive radio waves that activate a transponder in the portable device. Then, the activated transponder sends a transponder code signal to the vehicle 1, and the vehicle 1 performs ID verification (immobilizer verification) using a code that is included in the transponder code signal. In this case, in-vehicle verification, which must be established to start the engine, does not have to be performed after the key operation-free system 2 establishes ID verification (in-vehicle verification) and may be performed when any one of the key operation-free system 2 and the immobilizer system establishes ID verification.
The mechanical operation type door lock system 36 is not limited to vehicles, and may be used in various components for opening and closing components such as the door of a house and the like.
In the illustrated example, the holes 42 of the key code pattern 41 are arranged in the vicinity of only one of the corner portions of the card key 38 (e.g., the right angle corner portion 38a) and the other corner portions are flat and do not include such structures in their vicinities. However, projections or holes that are not part of the key code pattern 41 may be formed in the vicinity of the other corner portions.
In the illustrated example, the holes 42 and non-hole portions 43 of the key code pattern 41 are arranged at intersections of the first inclined lines, which are inclined to the first side 40a of the card key 38, and the second inclined lines, which are inclined to the second side 40b and the center line La. However, the holes 42 and non-hole portions 43 of the key code pattern 41 may be arranged at intersections of a plurality of lines parallel to the first side 40a of the card key 38 and a plurality of lines parallel to the second side 40b of the card key 38.
The present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.

## Claims

1. A mechanical key code verification system comprising:
a mechanical key; and
a lock apparatus into which the mechanical key is insertable;
the mechanical key including:
a key body having at least one plane; and
a key code pattern including a plurality of recessed portions and a plurality of non-recessed portions formed on the at least one plane of the key body, the key code pattern having line symmetry, wherein the plurality of recessed portions and the plurality of non-recessed portions in the key code pattern are arranged to be symmetric about a bisector of a right angle corner portion of the mechanical key.

2. The mechanical key code verification system according to claim 1, wherein:
the mechanical key code verification system is a mechanical operation type key system arranged in a vehicle including an electronic key system which verifies an electronic key code transmitted through wireless communication from an electronic key; and
the mechanical key is an emergency key for the electronic key system.

3. The mechanical key code verification system according to claim 1, wherein the mechanical key is a card key.

4. The mechanical key code verification system according to claim 3, wherein the plurality of recessed portions in the key code pattern are through holes.

5. The mechanical key code verification system according to claim 1, wherein:
the lock apparatus includes:
a support member;
a movable member which is movable relative to the support member; and

a plurality of pin tumblers, each including a first lock pin arranged in the movable member and a second lock pin arranged in the support member, in which mechanical verification of the key code pattern is established thereby enabling the movable member to be movable when a shear line between the first lock pins and the second lock pins of the plurality of pin tumblers in the lock apparatus is aligned with a shear line between the movable member and the support member in the lock apparatus.

6. The mechanical key code verification system according to claim 1, wherein:
the mechanical key is a card key including a plurality of corner portions;
the plurality of recessed portions of the key code pattern are formed in the vicinity of a single one of the plurality of corner portions; and
the vicinities of the other corner portions are flat.