GB2611827A

GB2611827A - Automatically-locked lock after being bumped

Info

Publication number: GB2611827A
Application number: GB2116468.6A
Authority: GB
Inventors: Liu Tien-Kao
Original assignee: Federal Lock Co Ltd
Current assignee: Federal Lock Co Ltd
Priority date: 2021-10-13
Filing date: 2021-11-16
Publication date: 2023-04-19
Also published as: TW202316018A; GB202116468D0; TWI781789B; EP4166738A1

Abstract

A cylinder lock comprises external key operated cylinder with selective transmission drive 21, biased e.g. spring 22 toward cam 4 and interior operated thumb-turn and sleeve 5 and having engaging member 33 and driving member 34 biased, e.g. spring 32 toward cam 4. Transmission drives 34, 21 are axially movable with radial lugs for selective engagement with cam. Inner cylinder housing 6 has tamper pins 72, 73 which during normal use engage periphery 332 of engaging member 33. Upon external cylinder 2 being snapped and removed during attack driving member 34 moves further axially and tamper pins 73 locate between head 332 and shaft 31 and pins 72 straddle sleeve 5 and housing 6 locking the cylinder; pins 73 and 72 can be dis-engaged by manually axially pushing in the thumb-turn/knob 3. Preferably driving member 34 includes a notch 341 in which locates radially biased blocking member 421 when driving member 34 over-travels axially during tampering.

Description

AUTOMATICALLY-LOCKED LOCK AFTER BEING BUMPED BACKGROUND OF THE INVENTION

I. Fields of the invention

The present invention relates to an automatically-locked lock after 5 one lock cylinder is bumped, and the lock can be unlocked from other end of the lock by operating the knob.

2. Descriptions of Related Art

The conventional locks generally include top pins and bottom pins to be correctly arranged to obtain safety purposes. Unauthorized persons try to relocate the top pins and the bottom pins to unlock the lock by moving the top and bottom pins. However, it is difficult to relocate the top and bottom pins if the arrangement of the top and bottom pins are arranged in a complicated pattern. Some unauthorized persons may directly hit or damage the lock to break the connection between the lock cylinder and the housing of the lock to pick the lock cylinder out from the lock. Therefore, the lock is easily unlocked without the lock cylinder regardless of the complicity of the arrangement pattern of the top and bottom pins. In other words, as long as the damage force applied to the lock is larger than the strength of the housing of the lock, the lock can be unlocked.

An improved lock is disclosed in CN 105649408A and includes a first clutch assembly which has a compression spring and a first clutch member. The first clutch member has a rod with stepped outer surface and includes driving parts. An insertion member made by high-strength steel is installed in the axial hole of the first clutch member. The first clutch member includes a locking pin which is biased outward radially by a spring. A second clutch assembly includes a second clutch member which includes a stepped outer surface and a driving member which extends axially from the second clutch member. The second clutch assembly further includes an urging pin which axially contacts a large-diameter portion of the second clutch member. When the second lock cylinder is individually removed, or the second lock cylinder and the second activation member are removed from the housing, the urging pin and the second clutch member drop, so that the compression spring pushes the first clutch member, and the locking pin is biased by the spring and protrudes to be engaged with the pin hole of the first lock cylinder to lock the clutch member. The locking member also protrudes the pin hole and is engaged with another pin hole in the cam shaft. Therefore, the cam is restricted by the first lock cylinder, so that the unauthorized person cannot rotate the cam to unlock the lock, while the person in the room is able to operate the first lock cylinder and unlock the lock.

When the user in the room and wants to unlock the lock, by using 20 a correct key and pressing the press-button, the lock can be unlocked, instead to re-arrange the top and bottom pins. Therefore, when the second lock cylinder and the second activation member are removed, the unauthorized person may also be able to unlock the lock by using a tool to damage the lock and then rotate the first clutch member.

The present invention intends to provide a lock that is automatically 5 locked to eliminate shortcomings mentioned above.

SUMMARY OF THE INVENTION

The present invention relates to a lock and a body having a lock cylinder mounted to the first end thereof and a knob is connected to the second end of the body. A cam is located between the lock cylinder and the knob. The lock cylinder includes a transmission member facing the cam. A resilient element biases the transmission member to push the transmission member toward the cam. The transmission member is engaged with the cam when the lock is in an unlocked position. A sleeve is mounted to the second end of the body and located corresponding to the cam. The knob includes a shaft which is axially and movably located in the sleeve so as to rotate the sleeve. A spring, an engaging member and a driving member are located to the first end of the shaft and face the cam. The engaging member has a contact portion which includes a head protruding radially from the distal end thereof The cam includes a passage that is located corresponding to the driving member and the transmission member.

A first housing is connected to the second end of the body and mounted to the sleeve. At least one stop unit is radially connected to the first housing. The at least one stop unit includes an elastic member, a stop block and an end block. The sleeve includes a reception hole to accommodate the end block. In an initial position, the contact area between the stop block and the end block is located corresponding the contact area between the first housing and the sleeve. A guide face is formed on the first end of the shaft so as to push the end block in radial direction. When in the initial position, the driving member and the transmission member are located in the passage and are directly or indirectly contact each other. The end block resiliently contacts the outside of the head. When in a locked position, the transmission member is not biased by the resilient element so that the spring pushes the engaging member and the driving member to push the transmission member away from the unlock position, and the head is not aligned with the end block so that the end block is pushed by the elastic member to contact the contact portion and is located between the head and the shaft. The stop block is located at the contact area between the first housing and the sleeve. When in a ready-tounlock position, the knob is axially moved, the guide face of the shaft pushes the end block radially so that the contact area between the stop block and the end block is located corresponding to the contact area between the first housing and the sleeve.

Preferably, the sleeve includes an elongate slot. The shaft includes a guide part located in the elongate slot.

Preferably, the shaft includes an axial recess formed radially therein. The elastic member is located in the axial recess and biases the contact 5 portion.

Preferably, a driver is located between the sleeve and the cam. The sleeve drives the cam by the driver.

Preferably, the driving member includes a notch formed radially therein. A restriction unit is radially located in the passage and located corresponding to the notch. The restriction unit is resiliently engaged with the notch when the restriction unit is aligned with the notch. When in the initial position, the restriction unit is not aligned with the notch. When in the locked position, the driving member is pushed by the spring to push away the transmission member so that the restriction unit is aligned with the notch.

Preferably, the collar is connected to the lock cylinder and faces the cam. The collar includes a keyway defined axially in the inner periphery thereof The transmission member is located in the collar and includes a protrusion protruding radially therefrom. The protrusion is located in the keyway. An axial groove is defined axially in the inner periphery of the passage. The protrusion is axially movable in the axial groove. The protrusion radially rotates the cam.

Preferably, the lock cylinder includes a key hole defined axially therein. An arm member is located between the lock cylinder and the transmission member so as to cover up the key hole and contacts the transmission member.

Preferably, the arm member includes at least one first arm extending radially therefrom. A second arm is formed to the at least one first arm at an angle and toward the lock cylinder. An end part is formed to the distal end of the second arm. The lock cylinder includes at least one reception recess defined radially therein which is located corresponding to the second arm and the end part.

Preferably, the collar includes a chamber located corresponding to the at least one first arm. The chamber communicates with the keyway.

Preferably, a link and the resilient element are located between the arm member and the transmission member. The arm member contacts the transmission member by the link and the resilient element.

The advantages of the present invention are that by the knob and the spring, the engaging member and the driving member, in the initial position, the driving member and the transmission member are located in the passage and are directly or indirectly contact each other. The end block resiliently contacts the outside of the head. When the lock cylinder is damaged and pulled out from the end opposite to the knob, because the transmission member is not pushed by the resilient element so that the resilient element pushes the engaging and the driving member, such that the head is not radially located corresponding to the end block. The end block is pushed the resilient member to contact the contact portion, and is located between the head and the shaft. The stop block is located at the contact area between the first housing and the sleeve. Therefore, when the lock is not set to the ready-to-unlock position, the lock cannot be unlocked by rotating the cam from neither the end with the knob nor the end with the damaged. When the knob is axially moved to the ready-to-unlock position, the shaft radially pushes the end block so that the contact area between the stop block and the end block is located corresponding to the contact area between the first housing and the sleeve. The knob is then rotated so that the lock is unlock to avoid the user from being locked inside the room.

In case the lock cylinder is damaged from one end of the lock, thanks to the restriction plate and the stop, the collar and the transmission member are not removed from the cam, and the collar and the transmission member are freely rotatable relative to the cam to protect the driving member from being damaged by bumping attack.

The arm member covers up the key hole so that the transmission 20 member cannot be seen and accessed directly from the key hole, so as to prevent the transmission member from being touched or damaged by inserting a tool from the key hole. Therefore, the arm member protects the transmission member to enhance safety of the lock.

The present invention will become more obvious from the following description when taken in connection with the accompanying 5 drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTTON OF THE DRAWINGS

Fig. 1 is a perspective view to show the lock of the present invention; Fig. 2 is an exploded view of the lock of the present invention; Fig. 3 is a cross sectional view of the lock of the present invention when the lock is in the initial position; Fig. 4 is a cross sectional view of the restriction unit of the lock of the present invention when the lock is in the initial position; Fig. 5 is a cross sectional view to show that a correct key is inserted into the lock of the present invention when the lock is in the initial position; Fig. 6 is a cross sectional view of the lock of the present invention when the lock is in the locked position; Fig. 7 is a cross sectional view of the restriction unit of the lock of the present invention when the lock is in the locked position, and Fig. 8 is a cross sectional view of lock of the present invention when the lock is in the ready-to-unlock position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figs. 1 to 3, the lock of the present invention comprises a body 1 having a lock cylinder 2 mounted to the first end thereof, and a knob 3 is connected to the second end of the body 1. A cam 4 is located between 5 the lock cylinder 2 and the knob 3. The body 1 of the lock is installed to a separation object (not shown) such as a door, and the cam 4 achieves the antitheft purpose by the cam 4. Generally speaking, the knob 3 is located in the room and the lock cylinder 2 is located close to the outside of the room. The lock cylinder 2 is rotated by using a correct key in this embodiment. The lock 10 cylinder 2 includes a transmission member 21 facing the cam 4. A resilient element 22 biases the transmission member 21 to push the transmission member 21 toward the cam 4. The transmission member 21 is engaged with the can 4 when the lock is in an unlocked position.

A sleeve 5 is mounted to the second end of the body 1 and located corresponding to the cam 4. The knob 3 includes a shalt 31 which is axially and movably located in the sleeve 5 so as to rotate the sleeve 5 in the rotational direction. A spring 32, an engaging member 33 and a driving member 34 are located to the first end of the shaft 31 and facing the cam 4. The engaging member 33 has a contact portion 331 which includes a head 332 protruding radially from the distal end thereof The cam 4 includes a passage 41 that is located corresponding to the driving member 34 and the transmission member 21.

A first housing 6 is connected to the second end of the body 1 and mounted to the sleeve 5. At least one stop unit 7 is radially connected to the first housing 6. The sleeve 5 includes a reception hole 53 located corresponding to the at least one stop unit 7. The at least one stop unit 7 includes an elastic member 71 a stop block 72 and an end block 73. The reception hole 53 accommodates the end block 73 which contacts the engaging member 33. The elastic member 71 and the stop block 72 are located in the first housing 6. The first housing 6 includes a room 61 to accommodate the elastic member 71 and the stop block 72 therein. The elastic member 71 biases the stop block 72 and the end block 73 toward the engaging member 33. In an initial position, as shown in Fig. 3, the contact area between the stop block 72 and the end block 73 is located corresponding the contact area between the first housing 6 and the sleeve 5. By rotating the knob 3, the shaft 31 drives the sleeve 5 and the cam 4 in sequence to unlock the lock. A guide face 311 is formed on the first end of the shaft 31 so as to push the end block 73 in radial direction.

When in the initial position, as shown in Figs. 3 and 5, the driving 20 member 34 and the transmission member 21 are located in the passage 41, and are directly or indirectly contact each other. The end block 73 resiliently contacts the outside of the head 332. In this embodiment, the driving member 34 and the transmission member 21 are located in the passage 41 and contact each other. In another embodiment, the driving member 34 and the transmission member 21 indirectly contact each other due to request of the 5 axial length of the driving member 34. As mentioned above, the lock can be unlocked by rotating the knob 3 to let the shaft 31 drive the sleeve 5 and the cam 4 in sequence. On the outside of the room, the lock with the lock cylinder 2, the lock can be unlocked by inserting the correct key into the lock cylinder 2. The correct key directly or indirectly drives the transmission member 21 10 to the unlocked position as shown in Fig. 5. The transmission member 21 drives the cam 4 to rotate the lock cylinder 2 to unlock the lock.

As shown in Figs. 6 and 7, when the transmission member 21 is not biased by the resilient element 22, such as the lock cylinder 2 is damaged and pulled out, because the transmission member 21 is cooperated with the lock cylinder 2, so that the transmission member 21 on the damaged end of the lock is not biased by the resilient element 22 when the lock cylinder 2 is pulled out from the lock. Under this situation, the spring 32 pushes the engaging member 33 and the driving member 34 to push the transmission member 21 away from the unlock position. Therefore, the transmission member 21 cannot be engaged with the cam 4, and the engaging member 33 is biased by the spring 32, so that the head 332 is not aligned with the end block 73. Therefore, the end block 73 is pushed by the elastic member 71 to contact the contact portion 331 and is located between the head 332 and the shaft 31, such that the engaging member 33 cannot be pushed back from the damaged end of the lock. The stop block 72 is located at the contact area 5 between the first housing 6 and the sleeve 5. Because the stop block 72, the cam 4 cannot be rotated from the damaged end of the lock cylinder 2. In this situation, regardless rotating the knob 3 directly or indirectly, the stop block 72 contacts the contact area between the first housing 6 and the sleeve 5 so that the lock cannot be unlocked. In other words, the lock is automatically 10 locked after the lock is damaged.

It is noted that because the knob 3 may be moved so that the reception hole 53 of the sleeve 5 is not completely aligned with the room 61 of the first housing 6, such that the stop block 72 is biased by the elastic member 71 and contacts the outside of the sleeve 5, instead of the reception hole 53. and this may lead to failure of the automatically-locked feature.

When the lock is not yet locked, as mentioned before, the knob 3 is rotated along with the rotation of the cam 4, so that the sleeve 5 includes multiple reception holes 53 in one embodiment, and each reception hole 53 accommodates one end block 73. Accordingly, when the lock cylinder 2 is damaged and the unauthorized person tries to rotate the cam 4, once one of the reception holes 53 is in alignment with the room 61, the lock is automatically locked. The cam 4 cannot be rotated because the stop block 72 contacts the contact area between the first housing 6 and the sleeve 5.

When the lock is to be unlocked, as shown in Fig. 8, the user needs to push the knob 3 axially from the inside of the room for example, the guide 5 face 311 of the shaft 31 pushes the end block 73 radially so that the contact area between the stop block 72 and the end block 73 is located corresponding to the contact area between the first housing 6 and the sleeve 5. Therefore, the knob 3 is rotated to unlock the lock, because the guide face 311 of the shaft 31 radially pushes the end block 73. The guide face 311 can be an 10 inclined face. Alternatively, the end block 73 includes a guide face to achieve the same purpose.

The sleeve 5 includes an elongate slot 51 defined axially therein, and the shaft 31 includes a guide part 312 located in the elongate slot 51. Because the sleeve 5 is pivotably connected to the first housing 6 and can only be rotated relative to the first housing 6. In other words, the sleeve 5 cannot move axially relative to the first housing 6. By the elongate slot 51 and the guide part 312, the shaft 31 is able to axially move in the sleeve so as to axially move the knob 3 to reach to the ready-to-unlock position. In addition, the shaft is able to rotate the sleeve 5 to rotate the cam 4 to unlock the lock.

The shaft 31 includes an axial recess 313 formed radially therein. The elastic member 71 is located in the axial recess 313 and biases the contact portion 331. The elastic member 71 does not tilt or twisted when in operation so as to ensure stability of operation of the lock.

For the transmission between the sleeve 5 and the cam 4, in this embodiment, a driver 52 is located between the sleeve 5 and the cam 4. The sleeve 5 drives the cam 4 by the driver 52 to simplify the structure and to benefit the manufacturing.

In order to increase the safety feature so that when the lock is in the locked position, the unauthorized person cannot damage the cam 4 in the damaged end of the lock by drilling, hitting or the like. The driving member 34 includes a notch 341 formed radially therein. A restriction unit 42 is radially located in the passage 41 and located corresponding to the notch 341. The restriction unit 42 is resiliently engaged with the notch 341 when the restriction unit 42 is aligned with the notch 341. When in the initial position, as shown in Figs. 3 to 5, the restriction unit 42 is not aligned with the notch 341. When in the locked position, as shown in Figs. 6 and 7, the driving member 34 is pushed by the spring 32 to push away the transmission member 21 so that the restriction unit 42 is aligned with and engaged with the notch 341.

In order to enhance stability between the notch 341 and the restriction unit 42, the notch 341 is a rectangular notch, and the restriction unit 42 includes a block 421 and at least one spring 422. The block 421 is shaped to match the notch 31 so that the block 421 is engaged with the notch 341 at large contact area to prevent the block 421 from dropping from the notch 341 by hitting so as to fail the feature of automatically locked when the lock is in the locked position. The spring 422 contacts the inside of the passage 41 and biases the block 421. When in the initial position, as shown in Figs. 3 and 4, because the notch 341 is not aligned with the restriction unit 42, so that the block 421 is biased by the spring 422 and contacts the driving member 34, the transmission member 21 or the lateral side of a slide member between the driving member 34 and the transmission member 21. When in the locked position, as shown in Figs. 6 and 7, the block 421 is aligned with the notch 341, and the block 421 is engaged with the notch 341. In order not let the spring 422 be compressed by the block 421 when the lock is hit, the number of the springs 422 can be plural to prevent the springs 422 from being compressed. Besides, in order to prevent the spring 422 from being tilt due to hitting, the block 421 includes an end piece 4211 that is located corresponding to the spring 422. In one embodiment, the end piece 4211 can be a notch so that the spring 422 is accommodated in the notch to ensure that the spring 422 is not tilt and disengaged from the notch.

When in the ready-to-unlock position as mentioned above, because the notch 341 and the restriction unit 42 axially lock the driving member 34 and the cam 4, so that the cam 4 and the knob 3 are able to rotate simultaneously. Therefore, when the knob 3 is rotated, the driving member 34 drives the cam 4 to unlock the lock, so that the user in the room can unlock the lock by operating the knob 3.

The cam 4 includes a bore 43 which is located corresponding to the restriction unit 42, and the spring 422 and at least a portion of the block 421 are located in the bore 43. Preferably, the bore 43 is a through bore and a cover 431 is connected to the bore 43. The spring 422 is biased between the cover 41 and the block 421. In one embodiment, because the cam 4 includes a tongue 44 to lock the door, so that the bore 43 needs to be located not to interfere the tongue 44. The notch 341 is made to be a rectangular notch to simplify the shape of the driving member 34. The automatically-locked feature can be achieved without complicated structure.

The body I includes two rods 11 respectively extending axially from two ends thereof, one of the two rods 11 that faces the lock cylinder 2 is connected with a second housing 12 which accommodates the lock cylinder 2. The other one of the two rods 11 is connected with the first housing 6. The rods 11 are made to be easily broken when the lock is hit or bumped, so that the automatically-locked feature can be maintained. In one embodiment, the rods 11 each have an annular groove 111 so that the rods 11 are broken at the annular grooves 111 to protect the body 1 from being damaged.

The collar 23 is connected to the lock cylinder 2 and faces the cam 4. The collar 23 includes a keyway 231 defined axially in the inner periphery thereof The transmission member 21 is located in the collar 23 and includes a protrusion 211 protruding radially therefrom. The protrusion 211 is located in the keyway 231. An axial groove 411 is defined axially in the inner periphery of the passage 41. The protrusion 211 is axially movable in the axial groove 411, and the protrusion 211 is able to radially rotate the cam 4.

In order to avoid the transmission member 21 from being removed from the cam 4 when the lock cylinder 2 is damaged, and the driving member 34 is covered and protected from being damaged, preferably, the collar 23 is freely rotatable relative to the cam 4 as shown in Fig. 2. The transmission member 21 includes a radial hole 212, and the collar 23 includes a stop 232 that is biased by a resilient member 233 to be contact against the outside of the transmission member 21. When in the locked position, the stop 232 is received in the radial hole 212 to secure the transmission member 21 and the collar 23, so that the transmission member 21 cannot move axially and cannot be removed to enhance the cover-up feature. As mentioned above, in the locked position, the transmission member 21 is pushed away from the axial groove 411 so that the transmission member 21 and the collar 23 can only be freely rotatable relative to the cam 4, and cannot rotate the cam 4.

In addition, the collar 23 includes an annular receiving groove 234 defined radially therein. The cam 4 includes a receiving space 45 defined axially therein so as to receive the collar 23 therein. The cam 4 includes a fixing hole 46 which is located corresponding to the annular receiving groove 234. A restriction plate 461 is located in the fixing hole 46 and is located corresponding to the annular receiving groove 234. Because the body 1 is located in the door so that the restriction plate 461 is hidden in the door. The restriction plate 461 is inserted into the annular receiving groove 234 to restrict the collar 23 in axial direction. The annular receiving groove 234 is formed in the outside of the collar 23 so that the collar 23 is freely rotatable relative to the cam 4 and is axially positioned to the cam 4. Therefore, when the lock cylinder 2 is removed, the collar 23 is axially positioned to the cam 4 and cannot be removed. Accordingly, the driver 52 and the driving member 34 on the other end of the lock are covered up and prevented from being hit and damaged.

The cam 4 includes an engaging groove 47 defined in an outside thereof, and the fixing hole 46 is formed in the inner end of the engaging 20 groove 47. At least one clip 48 is engaged with the engaging groove 47 to position the restriction plate 461. The at least one clip 48 is a C-clip and has an end loop 481 formed to each of two ends thereof The body 1 includes a recess 13 to accommodate the end loops 481. By the at least one clip 48, the cam 4 is rotatably located within the at least one clip 48. It is noted that by the engaging groove 47 and the at least one clip 48, the cam 4 is well positioned at its desired position to prevent from being shifted or tilt when the lock cylinder 2 is damaged. When the lock cylinder 2 is damaged and pulled out, the notch 341 of the driving member 34 on the other end of the lock is engaged with the restriction unit 42 to ensure that the automatically-locked feature is maintained. In one embodiment, the recess 13 is located at the bottom of the body 1, and the body 1 includes at least one pin hole 14 that is located corresponding to the recess 13. The at least one clip 48 is a C-clip and engaged with the engaging groove 47 to form an opening between the two ends of the at least one clip 48. Therefore, a pin 15 is used to extend through the end loops 481 on the two ends of the at least one clip 48 via the pin hole 14 to secure the end loops 481 to the recess 13.

In one embodiment, when the correct key is inserted into the lock cylinder 2 and drives the transmission member 21 which is located in the axial groove 411 of the passage 41. The collar 23, the transmission member 21 and the protrusion 211 drive the cam 4 to rotate when the lock cylinder 2 is rotated. The lock cylinder 2 includes a key hole 24 defined axially therein. An arm member 25 is located between the lock cylinder 2 and the transmission member 21 so as to cover up the key hole 24 and contacts the transmission member 21. The arm member 25 is a plate-like or a block. In this embodiment, the arm member 25 is a plate-like member, and is not limited thereto. The arm member 25 is located at one end of the lock cylinder 2 and the transmission member 21 so as to cover up the key hole 24 and contacts the transmission member 21. The arm member 25 covers up the key hole 24 facing the transmission member 21 so as to hide the transmission member 21, such that the transmission member 21 cannot be seen or accessed from outside of the lock cylinder 2. When the unauthorized person uses an elongate tool to insert into the key hole 24, the tool cannot touches the transmission member 21 to unlock the lock because the transmission member 21 is blocked by the arm member 25 to enhance the safety of the lock. As shown in Fig. 4, when the correct key is inserted into the lock, the correct ley pushes the arm member 25 to move the transmission member 21. As mentioned above, the protrusion 211 is moved to the axial groove 411 of the cam 4. In order to position the ann member 25 and restrict the movement distance of the arm member 25, in one embodiment, the arm member 25 includes at least one first arm 251 extending radially therefrom. A second arm 252 is folioed to the at least one first arm 251 at an angle and toward the lock cylinder 2. An end part 253 is formed to the distal end of the second aim 252. The lock cylinder 2 includes at least one reception recess 26 defined radially therein which is located corresponding to the second arm 252 and the end part 253. It is noted that the at least one reception recess 26 includes a engaging portion to restrict the end part 253 so as to restrict the axial distance that the arm member 25 moves. In order to prevent the collar 23 from interfering movement of the arm member 25, in one embodiment, the collar 23 includes a chamber 235 located corresponding to the at least one first aim 251. The chamber 235 communicates with the keyway 231. Therefore, when the aim member 25 is pushed by the correct key, the first arm 251 is inserted into the chamber 235 to ensure that the arm member 25 contacts the transmission member 21. Preferably, a link 27 and the resilient element 22 are located between the arm member 25 and the transmission member 21. The arm member 25 contacts the transmission member 21 by the link 27 and the resilient element 22. The resilient element 22 is not twisted or tilt. As shown in Fig. 4, when the correct key is inserted into the lock cylinder 2, as mentioned above, the arm member 25 pushes the transmission member 21, and the protrusion 211 of the transmission member 21 is inserted into the axial groove 411. When the correct key rotates the lock cylinder 2, the lock cylinder 2 drives the collar 23 so that the transmission member 21 is driven due to the cooperation of the protrusion 211 and keyway 231. The protrusion 211 is engaged with the axial groove 411 so that the cam 4 can be rotated to unlock the lock.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.

Claims

WHAT IS CLAIMED IS: 1. A lock comprising: a body (1) having a lock cylinder (2) mounted to a first end thereof, a knob (3) connected to a second end of the body (1), a cam (4) located between the lock cylinder (2) and the knob (3), the lock cylinder (2) including a transmission member (21) facing the cam (4), a resilient element (22) biasing the transmission member (21) to push the transmission member (21) toward the cam (4), the transmission member (21) being engaged with the can (4) when the lock is in an unlocked position; a sleeve (5) mounted to the second end of the body (1) and located corresponding to the cam (4), the knob (3) including a shaft (31) which is axially and movably located in the sleeve (5) so as to rotate the sleeve (5) in a rotational direction, a spring (32), an engaging member (33) and a driving member (34) located to a first end of the shaft (31) and facing the cam (4), the engaging member (33) having a contact portion (331) which includes a head (332) protruding radially from a distal end thereof, the cam (4) including a passage (41) that is located corresponding to the driving member (34) and the transmission member (21), and a first housing (6) connected to the second end of the body (1) and 20 mounted to the sleeve (5), at least one stop unit (7) radially connected to the first housing (6), the at least one stop unit (7) including an elastic member (71), a stop block (72) and an end block (73), the sleeve (5) including a reception hole (53) to accommodate the end block (73), in an initial position, a contact area between the stop block (72) and the end block (73) being located corresponding a contact area between the first housing (6) and the sleeve (5), a guide face (311) formed on the first end of the shaft (31) so as to push the end block (73) in radial direction; when in the initial position, the driving member (34) and the transmission member (21) are located in the passage (41) and are directly or indirectly contact each other, the end block (73) resiliently contacts an outside of the head (332), when in a locked position, the transmission member (21) is not biased by the resilient element (22) so that the spring (32) pushes the engaging member (33) and the driving member (34) to push the transmission member (21) away from the unlock position, and the head (332) is not aligned with the end block (73) so that the end block (73) is pushed by the elastic member (71) to contact the contact portion (331) and is located between the head (332) and the shaft (31), the stop block (72) is located at the contact area between the first housing (6) and the sleeve (5), when in an ready-to-unlock position, the knob (3) is axially moved, the guide face (311) of the shaft (31) pushes the end block (73) radially so that the contact area between the stop block (72) and the end block (73) is located corresponding to the contact area between the first housing (6) and the sleeve (5).
2. The lock as claimed in claim 1, wherein the sleeve (5) includes an elongate slot (51), the shaft (31) includes a guide part (312) located in the elongate slot (51).
3. The lock as claimed in claim 1, wherein the shaft (31) includes 5 an axial recess (313) formed radially therein, the elastic member (71) is located in the axial recess (313) and biases the contact portion (331).
4. The lock as claimed in claim 1, wherein a driver (52) is located between the sleeve (5) and the cam (4), the sleeve (5) drives the cam (4) by the driver (52).
5. The lock as claimed in claim 1, wherein the driving member (34) includes a notch (341) formed radially therein, a restriction unit (42) is radially located in the passage (41) and located corresponding to the notch (341), the restriction unit (42) is resiliently engaged with the notch (341 when the restriction unit (42) is aligned with the notch (341), when in the initial position, the restriction unit (42) is not aligned with the notch (341), when in the locked position, the driving member (34) is pushed by the spring (32) to push away the transmission member (21) so that the restriction unit (42) is aligned with the notch (341).
6. The lock as claimed in claim 1, wherein the collar (23) is 20 connected to the lock cylinder (2) and faces the cam (4), the collar (23) includes a keyway (231) defined axially in an inner periphery thereof, the transmission member (21) is located in the collar (23) and includes a protrusion (211) protruding radially therefrom, the protrusion (211) is located in the keyway (231), an axial groove (411) is defined axially in an inner periphery of the passage (41), the protrusion (211) is axially movable in the axial groove (411), the protrusion (211 radially rotates the cam (4).
7. The lock as claimed in claim 6, wherein the lock cylinder (2) includes a key hole (24) defined axially therein, an arm member (25) is located between the lock cylinder (2) and the transmission member (21) so as to cover up the key hole (24) and contacts the transmission member (21).
8. The lock as claimed in claim 7, wherein the arm member (25) includes at least one first arm (251) extending radially therefrom, a second arm (252) is formed to the at least one first arm (251) at an angle and toward the lock cylinder (2), an end part (253) is formed to a distal end of the second arm (252), the lock cylinder (2) includes at least one reception recess (26) defined radially therein which is located corresponding to the second arm (252) and the end part (253).
9. The lock as claimed in claim 8, wherein the collar (23) includes a chamber (235) located corresponding to the at least one first arm (251), the chamber (235) communicates with the keyway (231).
10. The lock as claimed in claim 7. wherein a link (27) and the resilient element (22) are located between the aim member (25) and the transmission member (21), the arm member (25) contacts the transmission member (21) by the link (27) and the resilient element (22).