Door lock emergency device

Abstract

The utility model discloses a door lock emergency device which comprises a lock shell, a handle transmission structure and a main spring bolt structure and further comprises a handle inside and outside shifting fork arranged on the inner bottom wall of the lock shell in a sliding mode through a sliding limiting piece, and the handle inside and outside shifting fork is in sliding fit with the interior of the handle transmission structure. The handle transmission structure is rotationally sleeved with a first spring bolt transmission piece connected with the handle inner and outer shifting fork, the main spring bolt structure is provided with a second spring bolt transmission piece meshed with the first spring bolt transmission piece, and a shifting fork pin is arranged on one side of the handle transmission structure in a sliding mode. The shifting fork pin is matched with the handle inner shifting fork and the handle outer shifting fork through an elastic positioning mechanism, and a safety twist linkage mechanism abutting against the shifting fork pin is further arranged in the lock shell. When a smart card, a fingerprint or a human face cannot perform communication unlocking on the lock body, the action of emergency unlocking can be realized, so that the door can be conveniently opened, and the condition that a person is locked indoors can be prevented.

Description

Technical Field

[0001] The present application relates to the technical field of locks, and particularly to an emergency device for a door lock. Background Art

[0002] At present, lock bodies are becoming more and more popular in life. A lock body is a common device in daily life and is often used for household doors, safes, computer room access control, etc. The unlocking methods of lock bodies generally include mechanical unlocking with a key and intelligent unlocking. With the continuous development of the smart home industry, lock bodies with intelligent unlocking are more and more favored and widely used by people. The intelligent unlocking methods generally include intelligent card swiping, fingerprint or face recognition unlocking, etc., which have high intelligence, convenience and security.

[0003] The intelligent lock bodies in the related art generally include a lock case, a main lock tongue structure, an oblique tongue structure and a handle transmission structure. When unlocking and opening the door is required, by using an intelligent card, fingerprint or face to approach the induction box outside the lock body, the induction box can communicate, so that the main lock tongue structure can drive the main lock tongue to retract into the lock case to achieve unlocking. Then, by pressing down the handle, the handle transmission structure can drive the oblique lock tongue on the oblique tongue structure to retract into the lock case, so as to achieve the effect of opening the door.

[0004] Regarding the above related art, the inventor believes that when the intelligent card, fingerprint or face cannot communicate and unlock the lock body, the door cannot be opened, and even the situation of locking people in the room may occur. Therefore, there is an urgent need for a device that can also perform emergency unlocking in the above situation. Utility Model Content

[0005] The purpose of the present application is to provide an emergency device for a door lock to solve the problem that when the intelligent card, fingerprint or face cannot communicate and unlock the lock body, the door cannot be opened, and even the situation of locking people in the room may occur.

[0006] An emergency device for a door lock provided by the present application adopts the following technical solution:

[0007] An emergency device for a door lock includes a lock case, a handle transmission structure and a main lock tongue structure, and further includes a handle inner and outer fork slidably arranged on the inner bottom wall of the lock case through a sliding limiting member. The handle inner and outer fork is slidably matched with the inside of the handle transmission structure. A first lock tongue transmission member connected to the handle inner and outer fork is rotatably sleeved on the handle transmission structure. A second lock tongue transmission member meshed with the first lock tongue transmission member is arranged on the main lock tongue structure. A fork pin is slidably arranged on one side of the handle transmission structure. The fork pin is matched with the handle inner and outer fork through an elastic positioning mechanism. An insurance torsion linkage mechanism that abuts against the fork pin is further arranged in the lock case.

[0008] Furthermore, the elastic positioning mechanism includes a pin rod connected to one side of the shift fork pin, one end of the pin rod is provided with a positioning piece that contacts the inner and outer shift forks of the handle, a contact sliding hole is opened on one side of the handle transmission structure, the shift fork pin, the pin rod and the positioning piece are simultaneously slidably arranged in the contact sliding hole, a fixing sleeve that slides with the pin rod is provided in the hole wall of the contact sliding hole, and an elastic piece is connected between the fixing sleeve and the shift fork pin.

[0009] Furthermore, the positioning member is a positioning pin block, one side of the positioning pin block is connected to one end of the pin rod, and the other side of the positioning pin block is in contact with the inner and outer shift forks of the handle.

[0010] Furthermore, the elastic member is a plurality of springs, one end of each of the plurality of springs is respectively connected to one side of the fixing sleeve, and the other end of each of the plurality of springs is respectively connected to one side of the shift fork pin.

[0011] Furthermore, the safety torsion linkage mechanism includes a toggle plate structure and a transmission plate structure slidably arranged on one side of the inner bottom wall of the lock shell, a linkage plate structure is hinged between the toggle plate structure and the transmission plate structure, an extrusion assembly tightly pressed against the fork pin is arranged between one side of the transmission plate structure and the inner bottom wall of the lock shell, and a safety torsion structure that cooperates with the toggle plate structure is also rotatably arranged on the inner bottom wall of the lock shell.

[0012] Furthermore, the extrusion assembly includes a clutch arranged on one side of the inner bottom wall of the lock housing, the output end of the clutch is slidably provided with a clutch push block that is tightly pressed against the fork pin, and one side of the transmission plate structure is provided with a transmission plate push head that is tightly pressed against the clutch push block.

[0013] Furthermore, a fork sliding hole connected to the contact sliding hole is provided inside the handle transmission structure, the inner and outer forks of the handle slide in sliding cooperation with the fork sliding hole, and a sliding groove corresponding to the fork sliding hole is provided on the inner bottom wall of the lock housing, and the inner and outer forks of the handle cooperate with the sliding groove.

[0014] Furthermore, the sliding limiter is a plurality of sliding limit blocks symmetrically arranged on both sides of the inner and outer forks of the handle, and the groove walls on both sides of the sliding groove are provided with sliding limit grooves matched with the sliding limit blocks.

[0015] Compared with the prior art, the beneficial effects of this application are:

[0016] When the lock body cannot be unlocked through communication with a smart card, fingerprint, or face recognition, it is possible to achieve the unlocking effect by using a smart card, fingerprint, or face recognition, and drive the diagonal locking tongue to retract into the lock shell through the handle transmission structure to achieve the door opening effect, so that normal unlocking and door opening can be carried out. At this time, the insurance torsion linkage mechanism is in the initial state, the fork pin is in the ejected state, and the inner and outer fork of the handle is in the idle rotation state; when rotating the handle transmission structure, the handle transmission structure can only drive the diagonal locking tongue to retract into the lock shell, and will not drive the first locking tongue transmission member to rotate, so that the first locking tongue transmission member will not drive the second locking tongue transmission member to rotate, thereby preventing the activation of the emergency device when unlocking with a smart card, fingerprint, or face recognition.

[0017] When the lock body cannot be unlocked through communication with a smart card, fingerprint, or face recognition, by rotating the insurance torsion linkage mechanism, the insurance torsion linkage mechanism compresses the fork pin, causing the fork pin to retract into the interior of the handle transmission structure. At this time, the fork pin is in tight contact with the inner and outer fork of the handle through the elastic positioning mechanism, so that the first locking tongue transmission member on the inner and outer fork of the handle is tightly pressed against the handle transmission structure. In this way, by rotating the handle transmission structure, the first locking tongue transmission member can be driven to rotate. Since the first locking tongue transmission member and the second locking tongue transmission member are meshed with each other, the second locking tongue transmission member will rotate to drive the main locking tongue on the main locking tongue structure to retract into the lock shell, and at the same time, the diagonal locking tongue also retracts into the lock shell, thus realizing the unlocking action to facilitate opening the door and preventing the situation of locking people inside the room. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the initial state of the emergency device of the door lock in the embodiment of the present application.

[0019] Figure 2 It is a schematic diagram of the unlocked state of the emergency device of the door lock in the embodiment of the present application.

[0020] Figure 3 It is a schematic diagram of the structure of the inner and outer fork of the handle, the sliding limit block, and the first locking tongue transmission member in the embodiment of the present application.

[0021] Figure 4 It is a schematic diagram of the structure of the elastic positioning mechanism in the embodiment of the present application.

[0022] Description of the Reference Numerals:

[0023] 1. Lock housing; 11. Sliding groove; 12. Sliding limit groove; 2. Handle transmission structure; 21. Contact sliding hole; 22. Fixed sleeve; 23. Spring; 24. Fork sliding hole; 3. Main lock tongue structure; 31. Second lock tongue transmission member; 4. Handle inner and outer forks; 41. Sliding limit block; 42. First lock tongue transmission member; 5. Fork pin; 51. Pin rod; 52. Positioning pin block; 6. Toggle plate structure; 7. Transmission plate structure; 71. Transmission plate push head; 8. Linkage plate structure; 9. Safety twist structure; 10. Clutch; 101. Clutch push block. DETAILED DESCRIPTION

[0024] The following is combined with Figures 1-4 This application is described in further detail.

[0025] The present application embodiment discloses a door lock emergency device, referring to Figure 1 and Figure 2 In this embodiment, the door lock emergency device includes a lock housing 1, a handle transmission structure 2, a main lock tongue structure 3, a handle inner and outer fork 4, a sliding limiter, a first lock tongue transmission member 42, a second lock tongue transmission member 31, a fork pin 5, an elastic positioning mechanism, and a safety torsion linkage mechanism. The handle transmission structure 2 is mounted on the inner bottom wall of the lock housing 1, and the handle transmission structure 2 cooperates with the external handle and the oblique tongue structure sliding on one side of the lock housing 1; when the external handle is rotated and pressed down, the handle transmission structure 2 drives the oblique tongue structure to retract into the interior of the lock housing 1 or extend out of the exterior of the lock housing 1, so as to achieve the effect of unlocking and locking.

[0026] The main lock tongue structure 3 is installed on the inner bottom wall of the lock shell 1, and the main lock tongue structure 3 cooperates with the external smart sensing box and the main lock tongue sliding on one side of the lock shell 1 respectively; when a smart card, fingerprint or face is used to approach the external smart sensing box, the sensing box communicates, so that the main lock tongue structure 3 can drive the main lock tongue to retract into the lock shell 1 or extend outside the lock shell 1 to achieve the effect of unlocking and locking.

[0027] The handle transmission structure 2, the external handle, the oblique tongue structure, the main lock tongue structure 3, the smart sensing box and the main lock tongue described above are all existing structures and will not be described in detail here.

[0028] At the same time, the handle inner and outer forks 4 are slidably installed on the inner bottom wall of the lock shell 1 through a sliding limiter, and a sliding groove 11 is opened on the inner bottom wall of the lock shell 1. The sliding groove 11 cooperates with the handle inner and outer forks 4 so that the handle inner and outer forks 4 pass through the moving limiter and slide on the inner bottom wall of the lock shell 1 along the sliding groove 11.

[0029] Specifically, the sliding limit members are multiple sliding limit blocks 41, which are symmetrically installed on both sides of the inner and outer fork 4 of the handle. Moreover, sliding limit grooves 12 are provided on both side walls of the sliding groove 11. The two sliding limit grooves 12 cooperate with the sliding limit blocks 41 respectively to achieve the effect of sliding limit on the inner and outer fork 4 of the handle, so that the inner and outer fork 4 of the handle is slidably limited on the inner bottom wall of the lock case 1 through the sliding limit blocks 41.

[0030] Meanwhile, a fork sliding hole 24 is provided inside the handle transmission structure 2. The fork sliding hole 24 corresponds to the sliding groove 11, and the fork sliding hole 24 cooperates with the inner and outer fork 4 of the handle, so that the inner and outer fork 4 of the handle extends into the fork sliding hole 24, and thus the inner and outer fork 4 of the handle is slidably engaged with the inside of the handle transmission structure 2 through the fork sliding hole 24. When the external handle is rotated and pressed down, the rotation of the handle transmission structure 2 and the rotation of the inner and outer fork 4 of the handle do not interfere with each other, so that the inner and outer fork 4 of the handle is in an idle rotation state at this time.

[0031] In addition, referring to Figure 2 and Figure 3 In this embodiment, the first lock tongue transmission member 42 is rotatably sleeved on the handle transmission structure 2, and the first lock tongue transmission member 42 is fixedly connected to the inner and outer fork 4 of the handle; the second lock tongue transmission member 31 is installed on the main lock tongue structure 3, and the second lock tongue transmission member 31 meshes with the first lock tongue transmission member 42. When the first lock tongue transmission member 42 rotates, it can drive the second lock tongue transmission member 31 to rotate, so that the main lock tongue structure 3 drives the movement of the main lock tongue through its own mechanical transmission, thereby achieving the effect of unlocking or locking.

[0032] By setting the structure in which the first lock tongue transmission member 42 and the inner and outer fork 4 of the handle are connected to each other, whether the handle transmission structure 2 is operated by rotating and pressing down the external handle; or the main lock tongue structure 3 is operated by using a smart card, fingerprint or face to communicate with the smart induction box; neither of these will affect the sliding of the first lock tongue transmission member 42 and the inner and outer fork 4 of the handle, so that the first lock tongue transmission member 42 and the inner and outer fork 4 of the handle are in an idle rotation state at this time, that is, it is also the normal use state of the lock body at this time.

[0033] In addition, referring to Figure 1 and Figure 4 In this embodiment, the fork pin 5 is slidably installed on one side of the handle transmission structure 2, and a contact sliding hole 21 is provided on one side of the handle transmission structure 2. The contact sliding hole 21 is communicated with the fork sliding hole 24; meanwhile, the fork pin 5 cooperates with the inner and outer fork 4 of the handle through an elastic positioning mechanism. The setting of the elastic positioning mechanism can effectively slide-position and elastically reset the fork pin 5.

[0034] The insurance torsion linkage mechanism is installed on the inner bottom wall of the lock case 1, and the insurance torsion linkage mechanism cooperates with the fork pin 5. Through the setting of the insurance torsion linkage mechanism, the fork pin 5 can be effectively pressed, so that the fork pin 5 retracts into the contact sliding hole 21 under the action of the elastic positioning mechanism, so as to realize the pressing contact with the inner and outer forks 4 of the handle, so that the inner and outer forks 4 of the handle are fixed to each other, and further the first lock tongue transmission part 42 and the second lock tongue transmission part 31 are meshed and linked with each other to realize the unlocking action.

[0035] The structures of the elastic positioning mechanism and the insurance torsion linkage mechanism are described in detail below:

[0036] Specifically, referring to Figure 1 and Figure 4 , in this embodiment, the elastic positioning mechanism includes a pin rod 51, a positioning member, a fixed socket 22 and an elastic member. Wherein, one end of the pin rod 51 is fixedly connected to one side of the fork pin 5, and the other end of the pin rod 51 is matched with the contact sliding hole 21 to be slidably arranged inside the contact sliding hole 21. The positioning member is a positioning pin block 52, one side of the positioning pin block 52 is installed at the end of the pin rod 51 far from the fork pin 5, and the positioning pin block 52 is slidably matched with the contact sliding hole 21.

[0037] When the fork pin 5 is squeezed by the insurance torsion linkage mechanism, the fork pin 5 retracts into the contact sliding hole 21, so that the fork pin 5 drives the positioning pin block 52 on the pin rod 51 to extend into the fork sliding hole 24 along the contact sliding hole 21 to press and contact the inner and outer forks 4 of the handle with each other, so that the inner and outer forks 4 of the handle are fixedly connected to the handle transmission structure 2.

[0038] At the same time, the fixed socket 22 is fixedly installed in the hole wall of the contact sliding hole 21, and a socket hole is opened in the middle of the fixed socket 22. The socket hole is matched with the pin rod 51, so that the pin rod 51 slides through the fixed socket 22 along the socket hole; the elastic member is connected between the fixed socket 22 and the fork pin 5. Specifically, the elastic member is a plurality of springs 23. One ends of the springs 23 are respectively connected to one side of the fixed socket 22, and the other ends of the springs 23 are respectively connected to one side of the fork pin 5, and the springs 23 are located in the contact sliding hole 21.

[0039] When the shift fork pin 5 is retracted to contact the inside of the sliding hole 21, the springs 23 are squeezed to make the springs 23 elastically contract; when the pressure of the shift fork pin 5 is removed, the springs 23 are elastically reset to pop the shift fork pin 5 out of the contact sliding hole 21, so that the shift fork pin 5 drives the positioning pin block 52 on the pin rod 51 away from the inner and outer shift forks 4 of the handle to loosen the inner and outer shift forks 4 of the handle.

[0040] Specifically, refer to Figure 1 and Figure 2 In this embodiment, the safety torsion linkage mechanism includes a toggle plate structure 6, a transmission plate structure 7, a linkage sheet structure 8, an extrusion assembly and a safety torsion structure 9. The toggle plate structure 6 is slidably mounted on one side of the inner bottom wall of the lock housing 1, and the toggle plate structure 6 is located on the side of the main lock tongue structure 3 away from the handle transmission structure 2; the transmission plate structure 7 is slidably mounted on one side of the inner bottom wall of the lock housing 1, and the transmission plate structure 7 is located on the side of the main lock tongue structure 3 away from the main lock tongue; the two ends of the linkage sheet structure 8 are respectively hinged between the toggle plate structure 6 and the transmission plate structure 7, so as to achieve the effect of linkage movement.

[0041] The extrusion assembly is installed between the lock housing 1 and the transmission plate structure 7, and the extrusion assembly and the fork pin 5 are tightly fitted with each other; the safety twist structure 9 is rotatably installed on the inner bottom wall of the lock housing 1, and the safety twist structure 9 is located on the side of the toggle plate structure 6 away from the main lock tongue structure 3, and the safety twist structure 9 cooperates with the toggle plate structure 6 to drive the toggle plate structure 6 to slide left and right.

[0042] More specifically, refer to Figure 1 and Figure 3 In this embodiment, the extrusion assembly includes a clutch 10, a clutch push block 101 and a transmission plate push head 71. The clutch 10 is mounted on one side of the inner bottom wall of the lock housing 1, and the clutch 10 is located on the side of the handle transmission structure 2 away from the main lock tongue structure 3; the clutch push block 101 is slidably mounted at the output end of the clutch 10, and the clutch push block 101 and the shift fork pin 5 are tightly pressed against each other; the transmission plate push head 71 is mounted on one end of the transmission plate structure 7 away from the linkage plate structure 8, and the transmission plate push head 71 and the clutch push block 101 are tightly pressed against each other to squeeze the shift fork pin 5.

[0043] When the safety torsion structure 9 is rotated by 90°, the safety torsion structure 9 drives the toggle plate structure 6 to move forward, so as to drive the transmission plate structure 7 to move forward through the linkage piece structure 8, so that the transmission plate push head 71 on the transmission plate structure 7 tightly slides out against the clutch push block 101. After the clutch push block 101 extends out, it compresses the fork pin 5, so that the fork pin 5 retracts into the fork sliding hole 24, and the fork pin 5 drives the positioning pin block 52 on the pin rod 51 to extend into the fork sliding hole 24 along the contact sliding hole 21, so as to tightly contact the inner and outer fork of the handle 4 with each other, so that the inner and outer fork of the handle 4 is fixedly connected to the handle transmission structure 2.

[0044] Then, by rotating the handle transmission structure 2, and then under the action of the meshing of the first latch transmission member 42 and the second latch transmission member 31, the main latch structure 3 drives the main latch to retract into the lock case 1. At this time, one side of the handle transmission structure 2 rotates to the transmission plate push head 71, so that the transmission plate push head 71 limits the handle transmission structure 2 to prevent the handle transmission structure 2 from continuing to rotate, so as to prevent the first latch transmission member 42 and the second latch transmission member 31 from disengaging from each other, and further enable the emergency unlocking action to prevent people from being locked in the room.

[0045] The implementation principle of an emergency device for a door lock in an embodiment of the present application is as follows:

[0046] When the smart card, fingerprint or face cannot communicate and unlock the lock body, by rotating the safety torsion structure 9 by 90°, the safety torsion structure 9 drives the toggle plate structure 6 to move forward, so as to drive the transmission plate structure 7 to move forward through the linkage piece structure 8, so that the transmission plate push head 71 on the transmission plate structure 7 tightly slides out against the clutch push block 101. After the clutch push block 101 extends out, it compresses the fork pin 5, so that the fork pin 5 retracts into the fork sliding hole 24 under the action of the spring 23, and the fork pin 5 drives the positioning pin block 52 on the pin rod 51 to extend into the fork sliding hole 24 along the contact sliding hole 21, so as to tightly contact the inner and outer fork of the handle 4 with each other, so that the inner and outer fork of the handle 4 is fixedly connected to the handle transmission structure 2.

[0047] Then, by rotating the handle transmission structure 2 to drive the first latch transmission member 42 to rotate, and then under the action of the meshing of the first latch transmission member 42 and the second latch transmission member 31, the second latch transmission member 31 is driven to rotate, so that the main latch structure 3 drives the main latch to retract into the lock case 1, and at the same time the diagonal latch also retracts into the lock case 1, so that the unlocking action can be realized to facilitate opening the door, and further complete the process of emergency unlocking in an emergency situation.

[0048] The above are only embodiments of the present utility model, and do not thus limit the patent scope of the present utility model. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of the present utility model.

Claims

1. An emergency device for a door lock, comprising a lock case (1), a handle transmission structure (2), and a main lock tongue structure (3), characterized in that: The lock body (1) further comprises an inner and outer handle shift fork (4) which is slidably arranged on the inner bottom wall of the lock housing (1) through a sliding limiter, the inner and outer handle shift fork (4) being slidably matched with the inside of the handle transmission structure (2), a first lock tongue transmission member (42) which is connected to the inner and outer handle shift fork (4) being rotatably sleeved on the handle transmission structure (2), a second lock tongue transmission member (31) which is meshed with the first lock tongue transmission member (42) being arranged on the main lock tongue structure (3), a shift fork pin (5) being slidably arranged on one side of the handle transmission structure (2), the shift fork pin (5) being matched with the inner and outer handle shift fork (4) through an elastic positioning mechanism, and a safety torsion linkage mechanism which is pressed against the shift fork pin (5) being also arranged in the lock housing (1).

2. The emergency device for a door lock according to claim 1, wherein: The elastic positioning mechanism comprises a pin rod (51) connected to one side of the shift fork pin (5); one end of the pin rod (51) is provided with a positioning member that contacts the inner and outer shift forks (4) of the handle; one side of the handle transmission structure (2) is provided with a contact sliding hole (21); the shift fork pin (5), the pin rod (51) and the positioning member are slidably arranged in the contact sliding hole (21) at the same time; a fixing sleeve (22) that slidably cooperates with the pin rod (51) is provided in the hole wall of the contact sliding hole (21); an elastic member is connected between the fixing sleeve (22) and the shift fork pin (5).

3. The emergency device for a door lock according to claim 2, wherein: The positioning member is a positioning pin block (52), one side of the positioning pin block (52) is connected to one end of the pin rod (51), and the other side of the positioning pin block (52) is in contact with the inner and outer shift forks (4) of the handle.

4. The emergency device for a door lock according to claim 2, wherein: The elastic member is a plurality of springs (23), one end of each of the plurality of springs (23) is respectively connected to one side of the fixing sleeve (22), and the other end of each of the plurality of springs (23) is respectively connected to one side of the shift fork pin (5).

5. The emergency device for a door lock according to claim 1, wherein: The safety torsion linkage mechanism comprises a toggle plate structure (6) and a transmission plate structure (7) which are slidably arranged on one side of the inner bottom wall of the lock housing (1); a linkage plate structure (8) is hinged between the toggle plate structure (6) and the transmission plate structure (7); an extrusion component which is tightly pressed against the shift fork pin (5) is arranged between one side of the transmission plate structure (7) and the inner bottom wall of the lock housing (1); and a safety torsion structure (9) which cooperates with the toggle plate structure (6) is also rotatably arranged on the inner bottom wall of the lock housing (1).

6. The emergency device for a door lock according to claim 5, wherein: The extrusion assembly comprises a clutch (10) arranged on one side of the inner bottom wall of the lock housing (1); a clutch push block (101) is slidably arranged at the output end of the clutch (10) and is tightly pressed against the shift fork pin (5); and a transmission plate push head (71) is arranged on one side of the transmission plate structure (7) and is tightly pressed against the clutch push block (101).

7. The emergency device for a door lock according to claim 2, characterized in that: A fork sliding hole (24) communicating with the contact sliding hole (21) is formed inside the handle transmission structure (2). The inner and outer handle fork (4) is slidably engaged with the fork sliding hole (24). A sliding groove (11) corresponding to the fork sliding hole (24) is formed on the inner bottom wall of the lock housing (1). The inner and outer handle fork (4) is engaged with the sliding groove (11).

8. An emergency device for a door lock according to claim 7, characterized in that: The sliding limit member is a plurality of sliding limit blocks (41) symmetrically arranged on both sides of the inner and outer handle fork (4). Sliding limit grooves (12) matching the sliding limit blocks (41) are formed on both side walls of the sliding groove (11).

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