CN211923794U

CN211923794U - Multi-side door fence

Info

Publication number: CN211923794U
Application number: CN202020301405.XU
Authority: CN
Inventors: 陈华
Original assignee: Zhejiang Litong Home Furnishing Co ltd
Current assignee: Zhejiang Litong Home Furnishing Co ltd
Priority date: 2020-03-12
Filing date: 2020-03-12
Publication date: 2020-11-13
Anticipated expiration: 2030-03-12

Abstract

The invention belongs to the technical field of household articles, and discloses a multi-direction door fence which comprises a plurality of door fence units which are sequentially connected end to end, wherein a polygonal space is formed by enclosing the door fence units, two adjacent door fence units are connected through a rotating connecting assembly, the rotating connecting assembly comprises two connecting blocks, the two connecting blocks are respectively connected with the two adjacent door fence units, the rotating connecting assembly further comprises a shaft sleeve and a clamping column, the clamping column is positioned in the shaft sleeve and is connected with the shaft sleeve in a lifting manner, a rotating shaft is arranged on the connecting blocks, the rotating shafts on the two connecting blocks are both rotatably connected with the same shaft sleeve, a gear is arranged on the rotating shaft, the clamping column is positioned between the two rotating shafts, a tooth groove which can be matched with the gear is arranged on the clamping column, and the clamping column can be. The multi-side door sill provided by the invention has the advantages of stable structure and convenience in adjustment.

Description

Multi-side door fence

Technical Field

The invention relates to the technical field of household articles, in particular to a multi-side door sill.

Background

The fence is used for defining a specific area indoors or outdoors to provide a safe activity place for children or pets, so as to prevent a series of accidents caused by the random climbing of the children or pets. In addition, the existing fences are mostly in polygonal structures with quadrangles and sides more than four. Most of fences also have the attribute of being folded and convenient to store, but such multi-side door fences do not have stability, and the shape is easily changed under the action of external force, so that the internal space of the fence is changed, and children or pets in the fence can be injured under severe conditions.

There is no threshold formula security fence for CN201820761154.6 among the prior art, this utility model though adopted corresponding coupling mechanism to provide the turnability for the rail, according to this utility model coupling mechanism adopt threaded connection mode to link together more, do not solve the instability problem of polygon rail. And still have and lead to corresponding threaded connection piece to screw out at the guardrail process of rotating, and then lead to the problem of whole rail structure inefficacy.

Disclosure of Invention

The invention aims to provide a multi-side door sill which has the advantages of stable structure and convenience in adjustment.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a many parties 'door fence, includes a plurality of door fence units that end to end connects gradually, and is a plurality of the door fence unit encloses to establish and forms the polygon space, connects through rotating coupling assembling between two adjacent door fence units, rotate coupling assembling and include two connecting blocks, two the connecting block is connected respectively in two adjacent door fence units, rotate coupling assembling still includes axle sleeve and jack, the jack is located in the axle sleeve and connect with liftable in the axle sleeve, be provided with the pivot on the connecting block, two on the connecting block the pivot is all rotated and is connected in same axle sleeve, be provided with the gear in the pivot, the jack is located two between the pivot, be provided with on the jack can with gear complex tooth's socket, the jack is followed during the axle sleeve goes up and down can with gear engagement or break away from.

Preferably, the shaft sleeve includes a housing and a base, the housing is hollow and has an open bottom, the base is located on the bottom of the housing and is detachably connected to the housing, and the rotating shaft extends into the housing from the bottom of the housing and is rotatably connected to the housing.

Preferably, the two rotating shafts are respectively positioned at two sides of the base, semicircular intervals matched with the appearance of the rotating shafts are formed in two side parts of the base, the shaft sleeve further comprises two supplementing blocks, and the supplementing blocks and the semicircular intervals of the base are oppositely arranged and form a circular interval for the rotating shafts to penetrate.

Preferably, the rotation connection assembly further comprises an elastic member, one end of the elastic member abuts against the base, and the other end of the elastic member abuts against the clamping column.

Preferably, the base is convexly provided with a bump, the elastic element is a spring, and the spring is sleeved outside the bump.

Preferably, the inner side of the shell is vertically provided with a convex strip, and the side part of the clamping column is vertically provided with a notch matched with the convex strip.

Preferably, the rotation connection assembly further includes a pressing member rotatably connected to the top of the clamping column, a through hole for the pressing member to extend out is formed in the top end face of the housing, a stopping portion is arranged on the inner side face of the housing, the stopping portion is arranged close to the outer edge of the through hole, an abutting portion is arranged on the periphery of the bottom end of the pressing member, and the abutting portion can abut against the stopping portion after the pressing member is pressed downwards and rotates for a certain angle relative to the clamping column so as to limit the pressing member to ascend.

Preferably, one of two surfaces of the abutting portion and the stopping portion contacting each other is provided with a protrusion, and the other surface is provided with a recess matching with the protrusion.

Preferably, the top of the pressing piece is provided with a hexagonal hole matched with a hexagonal wrench.

Preferably, at least one of the door fence units is an access door fence, the access door fence comprises a frame and a door, one side of the door is hinged to the frame, a locking device is connected between the other side of the door and the frame, the locking device comprises a handle box and a receiving box, the handle box comprises a box body, a horizontal push button connected in the box body, a lock tongue piece and a lock hook, the box body is connected to the door, the horizontal push button is connected on the box body in a sliding manner, the lock tongue piece is connected on the box body in a sliding manner and connected with the horizontal push button, the horizontal push button can drive the lock tongue piece to extend out or into the box body, the lock hook is connected in the box body in a sliding manner, the receiving box is connected to the frame, a lock tongue hole and a lock hook hole are formed in the receiving box, and the lock tongue hole is used for being matched with the lock tongue piece, the latch hook hole is used for being matched with the latch hook, the inner top surface of the latch hook hole is an inclined surface, and when the door is lifted up, the latch hook can slide out along the inclined surface of the latch hook hole.

The invention has the beneficial effects that: the invention provides a multi-side door fence, wherein in the meshing state of a clamping column and a gear, the clamping column only has lifting motion and can not rotate, so that a rotating shaft can not rotate when the gear is meshed with the clamping column, namely, two connecting blocks can not rotate, namely, two adjacent door fence units can not rotate, and the multi-side door fence is not easy to deform after being placed and has a stable structure; when the angle between two adjacent door fence units needs to be adjusted, the clamping column can be disengaged from the gear only by pressing the clamping column downwards, and the two rotating shafts can rotate freely, so that the angle between the two door fence units can be adjusted conveniently, the clamping column is reset after adjustment, the locking of the angle between the two door fence units can be realized, the adjusting process is convenient, the adjusting range is between 0-360 degrees, and the adjusting range is large.

Drawings

FIG. 1 is a schematic view of an enclosure structure of a multi-side door fence according to an embodiment;

FIG. 2 is a schematic diagram of a folded configuration of the multi-sided door fence according to an embodiment;

FIG. 3 is a schematic diagram of a rotary joint assembly according to an embodiment;

FIG. 4 is a schematic view of the embodiment providing a pivot connection assembly with the housing removed in the unlocked position;

FIG. 5 is a schematic view of the embodiment with the rotating link assembly removed from the housing in the locked position;

FIG. 6 is a schematic diagram of a structure of a card column provided in accordance with an embodiment;

FIG. 7 is a schematic view of a press according to an embodiment;

FIG. 8 is a schematic structural view of a housing according to an embodiment;

FIG. 9 is a cross-sectional view of an embodiment providing an access door fence;

fig. 10 is a partial enlarged view at a in fig. 9.

In the figure: 1. a door fence unit; 2. rotating the connecting assembly; 21. connecting blocks; 22. a shaft sleeve; 221. a housing; 2211. a convex strip; 2212. a through hole; 222. a base; 223. supplementing blocks; 224. a bump; 225. a stopper portion; 2251. a pit; 23. clamping the column; 231. a tooth socket; 232. a notch; 24. a rotating shaft; 241. a gear; 25. a spring; 26. a pressing member; 261. an abutting portion; 2611. a protrusion; 2612. a hexagonal hole; 3. a frame; 4. a door; 51. a handle box; 511. a box body; 512. horizontally pushing and twisting; 513. a latch member; 514. a latch hook; 515. a first spring; 516. a second spring; 517. a linkage member; 518. a third spring; 52. a receiving box; 521. a lock tongue hole; 522. a lock hook hole.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

As shown in fig. 1 to 10, the present invention provides a multi-side door fence, which includes a plurality of door fence units 1 connected end to end in sequence, wherein the plurality of door fence units 1 enclose a polygonal space (refer to the state shown in fig. 1), and two adjacent door fence units 1 are connected by a rotating connection assembly 2. The both ends of rotating coupling assembling 2 can be dismantled respectively and connect in two adjacent door hurdle units 1, the contained angle between two adjacent door hurdle units 1 can be adjusted, when should many ways of door hurdles accomodate, only need to rotate coupling assembling 2 and pull down from the door hurdle unit 1 rather than being connected with one of them, adjust the contained angle between the door hurdle unit 1 under rotating coupling assembling 2's effect afterwards, finally fold many ways of door hurdles (refer to the state shown in fig. 2), can conveniently accomodate these many ways of door hurdles.

As shown in fig. 3 to 5, the rotating connection assembly 2 includes two rotating blocks 21, the two rotating blocks 21 are respectively connected to two adjacent door sill units 1, the rotating connection assembly 2 further includes a shaft sleeve 22 and a clamping column 23, the clamping column 23 is located in the shaft sleeve 22 and is connected to the shaft sleeve 22 in a lifting manner, a rotating shaft 24 is provided on the rotating block 21, the rotating shafts 24 on the two rotating blocks 21 are both rotatably connected to the same shaft sleeve 22, a gear 241 is provided on the rotating shaft 24, the clamping column 23 is located between the two rotating shafts 24, a tooth slot 231 capable of being matched with the gear 241 is provided on the clamping column 23, and the clamping column 23 can be engaged with or disengaged from the gear 241 when lifting along the shaft sleeve 22.

In the state that the clamping column 23 is meshed with the gear 241 (refer to the state shown in fig. 5), because the clamping column 23 only has the lifting motion and can not rotate, the rotating shaft 24 can not rotate when the gear 241 is meshed with the clamping column 23, namely, the two rotating blocks 21 can not rotate, namely, the two adjacent door fence units 1 can not rotate, and the multi-side door fence is not easy to deform after being placed and has a stable structure; when the angle between two adjacent door fence units 1 needs to be adjusted, the clamping column 23 is only required to be pressed down, the clamping column 23 can be disengaged from the gear 241 (refer to the state shown in fig. 4), the two rotating shafts 24 can freely rotate, so that the angle between the two door fence units 1 can be conveniently adjusted, the clamping column 23 is reset after adjustment, the locking of the angle between the two door fence units 1 can be realized, the adjusting process is convenient, the adjusting range is between 0-360 degrees, and the adjusting range is large.

As shown in fig. 3-5 and 8, the shaft sleeve 22 includes a housing 221 and a base 222, the housing 221 is hollow and has an open bottom, the base 222 is located on the bottom of the housing 221 and is detachably connected to the housing 221, and the rotating shaft 24 extends into the housing 221 from the bottom of the housing 221 and is rotatably connected to the housing 221. The housing 221 and the base 222 are designed separately and detachably connected to facilitate installation. The two rotating shafts 24 are respectively located at two sides of the base 222, two side portions of the base 222 are provided with semicircular intervals matched with the shapes of the rotating shafts 24, the shaft sleeve 22 further comprises two patches 223, and the patches 223 are arranged opposite to the semicircular intervals of the base 222 and form a circular interval for the rotating shafts 24 to penetrate. The patch 223 and the base 222 are designed in a split mode and are respectively located on two sides of the rotating shaft 24, the patch 223 and the base 222 are convenient to mount in a split mode, the rotating shaft 24 is limited through a circular interval formed between the patch 223 and the base 222, a fit clearance between the rotating shaft 24 and the shaft sleeve 22 is filled, and the rotating shaft 24 is prevented from loosening.

In the present embodiment, the descending of the locking pin 23 is realized by pressing the locking pin 23, and in order to facilitate the ascending of the locking pin 23, the rotating connection assembly 2 further includes an elastic member, one end of which abuts against the base 222, and the other end of which abuts against the locking pin 23. When pressing down card post 23 and making card post 23 descend, the elastic component is compressed this moment, after card post 23 break away from with the pivot 24 between the engaged state, keep the state of continuously pressing down to card post 23, the contained angle between two adjacent door fence units 1 can be adjusted, after adjusting suitable angle, only need release the pressure to card post 23, card post 23 rises under the effect of the restoring force of elastic component, resumes original position. Through setting up the elastic component, can conveniently realize the elevating movement of card post 23. To facilitate the installation of the elastic element, a protrusion 224 may be protruded on the base 222, and the elastic element may be a spring 25, and the spring 25 is sleeved outside the protrusion 224. The height of the projection 224 should be less than the height of the spring 25 in the natural state and not affect the compression process of the spring 25.

In order to ensure that the movement of the clamping column 23 is only the lifting movement in the up-down direction, and the rotation cannot occur in the movement process, a protruding strip 2211 is vertically arranged on the inner side of the shell 221, and a notch 232 matched with the protruding strip 2211 is vertically arranged on the side portion of the clamping column 23. The notches 232 on the side of the locking column 23 are slidably connected to the protrusions 2211 inside the housing 221, and when the locking column 23 is lifted, the protrusions 2211 can limit the moving direction of the locking column 23 to be maintained along the extending direction of the protrusions 2211, and the locking column 23 cannot rotate. For more effectively limiting the clamping column 23 and avoiding the clamping column 23 from shaking in the shell 221, the two protruding strips 2211 can be arranged as two and are respectively located at the opposite sides of the shell 221, two notches 232 are respectively arranged at two sides of the clamping column 23, and the two notches 232 and the two protruding strips 2211 are matched in a one-to-one correspondence manner, so that the clamping column 23 can be more effectively limited and the movement direction can be limited.

As shown in fig. 6 to 8, the rotation connection assembly 2 further includes a pressing member 26, the pressing member 26 is rotatably connected to the top of the clamping column 23, a through hole 2212 for the pressing member 26 to extend out is formed in the top end surface of the housing 221, a stopping portion 225 is arranged on the inner side surface of the housing 221, the stopping portion 225 is arranged near the outer edge of the through hole 2212, an abutting portion 261 is arranged on the outer periphery of the bottom end of the pressing member 26, and the abutting portion 261 can abut against the stopping portion 225 after the pressing member 26 is pressed down and rotates for a certain angle relative to the clamping column 23, so as to limit the pressing member. The bottom of pressing member 26 is provided with the round hole that is used for pegging graft with calorie post 23, and pressing member 26 can block post 23 relatively and rotate, and outside the casing 221 was stretched out at the top of pressing member 26, when the contained angle between two adjacent door hurdle units 1 of adjustment, can be through applying pressure to pressing member 26 to drive card post 23 and descend, make calorie post 23 and gear 241 break away from the engaged state, thereby adjust the contained angle between two door hurdle units 1. Normally, only the pressure applied to the pressing piece 26 needs to be kept continuously, and the pressure applied to the pressing piece 26 is released after the included angle between the two door fence units 1 is adjusted to a proper position, but the mode needs to keep pressing the pressing piece 26 all the time, and the mode is convenient to operate during short adjustment; when the clamping column 23 and the gear 241 need to be kept in a separated state for a long time, the pressing piece 26 only needs to be pressed down and then rotated for a certain angle, so that the abutting portion 261 of the pressing piece 26 abuts against the stopping portion 225, at this time, the rotating connection assembly 2 is in an unlocked state, after the pressure on the pressing piece 26 is released, the stopping portion 225 can limit the pressing piece 26 to ascend, so that the clamping column 23 is always kept at a descending position and cannot be meshed with the gear 241, therefore, the angle between the door fence units 1 can be freely adjusted for a long time, the door fence can be adjusted to be in any shape, and the door fence can be folded to be conveniently packaged into a box for transportation and can be used after being taken out by a user.

In order to prevent the pressing member 26 from rotating when the abutting portion 261 and the stopper 225 need to be kept in the abutting state, one of the two surfaces of the abutting portion 261 and the stopper 225 contacting each other is provided with a protrusion 2611, and the other surface is provided with a recess 2251 engaging with the protrusion 2611. Thus, when the pressing piece 26 rotates to a position where the protrusion 2611 and the recess 2251 face each other, the protrusion 2611 and the recess 2251 can be matched with each other, thereby restricting rotation of the pressing piece 26 due to a slight external condition such as shaking.

Since the pressing member 26 enters the housing 221 when being pressed, in order to facilitate the rotation of the pressing member 26, a hexagonal hole 2612 adapted to a hexagonal wrench is formed at the top of the pressing member 26. When the pressing piece 26 needs to be rotated, the pressing piece 26 can be conveniently rotated by a certain angle while the pressing piece 26 is pressed only by using a matched hexagonal wrench.

In this embodiment, as shown in fig. 9 and 10, at least one of the door fence units 1 is an access door fence, the access door fence includes a frame 3 and a door 4, one side of the door 4 is hinged to the frame 3, a locking device is connected between the other side of the door 4 and the frame 3, the locking device includes a handle box 51 and a receiving box 52, the handle box 51 includes a box body 511, a horizontal push-button 512 connected in the box body 511, a latch member 513 and a latch hook 514, the box body 511 is connected to the door 4, the horizontal push-button 512 is slidably connected to the box body 511, the latch member 513 is slidably connected to the box body 511, the horizontal push-button 512 can drive the latch member 513 to extend out of or into the box body 511, the locking hook 514 is slidably connected to the box body 511, the receiving box 52 is connected to the frame 3, a latch hole 521 and a latch hole 522 are provided on the receiving box 52, the latch hole 521 is used for cooperating with the latch member 513, the latch hole 522 is, the inner top surface of the latch hook hole 522 is a slope, and the latch hook 514 can slide out along the slope of the latch hook hole 522 when the door 4 is lifted up. When the door is opened, the horizontal push button 512 is pulled, and the horizontal push button 512 can drive the latch piece 513 to be separated from the latch hole 521, so that the door 4 is unlocked from the frame 3. Meanwhile, through the cooperation of latch hook hole 522 and latch hook 514, can restrict door 4 and pull open from the fore-and-aft direction, when opening the door, can only lift a segment distance with this side of door 4 earlier for latch hook 514 breaks away from the back from latch hook hole 522, just can be opened from the fore-and-aft direction, can play the effect of multiple protection from this, avoids the unexpected condition of opening the door of toddler, ensures the security of use.

The handle box 51 further comprises a linkage 517, a first spring 515, a second spring 516 and a third spring 518, wherein the linkage 517 is slidably connected in the box body 511 and is connected with the horizontal push button 512, one end of the first spring 515 abuts against the linkage 517, the other end of the first spring 515 abuts against the box body 511, and the first spring 515 is used for driving the linkage 517 to reset; the bolt piece 513 is connected with the linkage piece 517, one end of a second spring 516 is connected with the bolt piece 513, the other end of the second spring 516 abuts against the box body 511, and the second spring 516 is used for driving the bolt piece 513 to reset; one end of the third spring 518 is connected to the latch hook 514, and the other end abuts against the box body 511, and the third spring 518 is used for driving the latch hook 514 to reset. When the door is opened, after the horizontal push button 512 is pulled, the horizontal push button 512 drives the linkage piece 517 to move towards the direction far away from the receiving box 52, and the linkage piece 517 can drive the bolt piece 513 to move, so that the bolt piece 513 is separated from the bolt hole 521; after the door is opened, the horizontal push button 512 is released, the linkage member 517 can reset under the action of the first spring 515, meanwhile, the horizontal push button 512 is driven to reset, and the bolt member 513 resets under the action of the second spring 516; when the door is closed, the horizontal push button 512 is only needed to be firstly pushed, and when the handle box 51 is opposite to the receiving box 52, the horizontal push button 512 is released, and the latch bolt piece 513 is inserted into the latch bolt hole 521 under the action of the second spring 516, so that the door is locked with the frame 3.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. The multi-party door fence is characterized by comprising a plurality of door fence units (1) which are sequentially connected end to end, wherein the door fence units (1) are arranged in an enclosing manner to form a polygonal space, two adjacent door fence units (1) are connected through a rotating connecting assembly (2), the rotating connecting assembly (2) comprises two rotating blocks (21), the two rotating blocks (21) are respectively connected to the two adjacent door fence units (1), the rotating connecting assembly (2) further comprises a shaft sleeve (22) and a clamping column (23), the clamping column (23) is positioned in the shaft sleeve (22) and is connected to the shaft sleeve (22) in a lifting manner, a rotating shaft (24) is arranged on each rotating block (21), the rotating shafts (24) on the two rotating blocks (21) are both rotatably connected to the same shaft sleeve (22), and a gear (241) is arranged on each rotating shaft (24), the clamping column (23) is located between the two rotating shafts (24), a tooth groove (231) capable of being matched with the gear (241) is formed in the clamping column (23), and the clamping column (23) can be meshed with or separated from the gear (241) when ascending and descending along the shaft sleeve (22).

2. The multi-side doorsill according to claim 1, wherein the shaft sleeve (22) comprises a housing (221) and a base (222), the housing (221) is hollow and has an open bottom, the base (222) is located at the bottom of the housing (221) and is detachably connected to the housing (221), and the rotating shaft (24) extends into the housing (221) from the bottom of the housing (221) and is rotatably connected to the housing (221).

3. The multi-side doorsill according to claim 2, wherein the two rotating shafts (24) are respectively located at two sides of the base (222), two side portions of the base (222) are provided with semicircular sections adapted to the shape of the rotating shafts (24), the shaft sleeve (22) further comprises two patches (223), and the patches (223) are arranged opposite to the semicircular sections of the base (222) and form a circular section for the rotating shafts (24) to penetrate through.

4. The multiple doorsill according to claim 2, characterized in that said rotating connection assembly (2) further comprises an elastic member, one end of said elastic member abuts against said base (222) and the other end abuts against said catch (23).

5. The multi-side doorsill according to claim 4, wherein a protrusion (224) is protruded from the base (222), the resilient member is a spring (25), and the spring (25) is sleeved outside the protrusion (224).

6. The multi-side doorsill according to claim 2, characterized in that a protruding strip (2211) is vertically disposed on the inner side of the housing (221), and a notch (232) adapted to the protruding strip (2211) is vertically disposed on the side of the fastening column (23).

7. The multi-side doorsill according to claim 2, wherein the rotating connection assembly (2) further comprises a pressing member (26), the pressing member (26) is rotatably connected to the top of the clamping column (23), a through hole (2212) for the pressing member (26) to extend out is formed in the top end surface of the housing (221), a stopping portion (225) is arranged on the inner side surface of the housing (221), the stopping portion (225) is arranged near the outer edge of the through hole (2212), an abutting portion (261) is arranged on the outer periphery of the bottom end of the pressing member (26), and after the pressing member (26) is pressed down and rotates for a certain angle relative to the clamping column (23), the abutting portion (261) can abut against the stopping portion (225) to limit the pressing member (26) to ascend.

8. The multiple doorsill according to claim 7, characterized in that one of the two surfaces of said abutment (261) and said stop (225) in contact with each other is provided with a protrusion (2611), and the other is provided with a recess (2251) cooperating with said protrusion (2611).

9. The multi-side doorsill according to claim 7, wherein a hexagonal hole (2612) for matching with a hexagonal wrench is opened at the top of the pressing member (26).

10. Multipart door fence according to any one of the claims 1-9, characterized in that at least one of the door fence units (1) is an access door fence comprising a frame (3) and a door (4), one side of the door (4) is hinged to the frame (3), between the other side of the door (4) and the frame (3) locking means are connected, which locking means comprise a handle box (51) and a receiving box (52), the handle box (51) comprising a box body (511), a horizontal push button (512) connected in the box body (511), a latch piece (513) and a latch hook (514), the box body (511) is connected to the door (4), the horizontal push button (512) is slidably connected to the box body (511), the latch piece (513) is slidably connected to the box body (511) and to the horizontal push button (512), horizontal push-button (512) can drive latch piece (513) stretch out or stretch into box body (511), latch hook (514) sliding connection in box body (511), accept box (52) connect in frame (3), be provided with latch hole (521) and latch hook hole (522) on accepting box (52), latch hole (521) be used for with latch piece (513) cooperation, latch hook hole (522) be used for with latch hook (514) cooperation, the interior top surface of latch hook hole (522) is the inclined plane, works as when door (4) lift, latch hook (514) can along the inclined plane roll-off of latch hook hole (522).