CN113749892B

CN113749892B - Field operation table capable of providing multi-position support for patient

Info

Publication number: CN113749892B
Application number: CN202111232254.2A
Authority: CN
Inventors: 赵晶; 刘佳佳; 连文琼; 何丽; 董薪
Original assignee: First Medical Center of PLA General Hospital
Current assignee: First Medical Center of PLA General Hospital
Priority date: 2021-10-22
Filing date: 2021-10-22
Publication date: 2023-04-25
Anticipated expiration: 2041-10-22
Also published as: CN113749892A

Abstract

The utility model relates to the technical field of field operation tools, in particular to a field operation table capable of providing multi-position support for patients; the outer frame and the rotary bed board are adopted, the deflection assembly is arranged in the hollow cavity of the outer frame, the driving shaft is rotated by a number one hand, and the driving shaft drives the worm wheel to rotate along with the worm, so that the main shaft deflects along with the bed board, and the operation angle is adjusted. The worm wheel and the worm adopt self-locking type, so that the bed plate can be positioned, and the self-rotation is avoided; the bottom surface of the outer frame is provided with a hollow storage seat and a supporting component, the adjusting shaft is rotated by two hands, and based on the action of threads, the movable nuts are enabled to be close to or far away from each other, so that the deflection rod is driven to deflect by the push-pull rod; the deflection rod deflects out of the storage seat to support the whole operating table, and meanwhile, the height of the operating table can be adjusted, so that a wounded can lie down conveniently; the deflection rod deflects into the storage seat to realize complete storage, so that the space occupation is reduced.

Description

Field operation table capable of providing multi-position support for patient

Technical Field

The utility model relates to the technical field of field operation tools, in particular to a field operation table capable of providing multi-position support for patients.

Background

In emergency rescue situations where traffic is interrupted, such as field operations, earthquakes, flood disasters and the like, basic equipment, such as an operating table, is still needed when an operation is required for wounded persons.

Although some carriage type mobile operating rooms exist in the prior art, for example, a novel field operation vehicle is disclosed in chinese patent No. CN200920009871.4, which is composed of a vehicle body, a carriage, an electric winch, a wire rope, a hook and the like, and is characterized in that: a cylindrical lead weight is sleeved on a steel wire rope above a hook of an existing field operation vehicle, a wooden Y-shaped jack retraction auxiliary device is added, and a generator box is hung outside a carriage behind a vehicle body. A lead weight is added above the steel wire rope hook of the operation vehicle, so that the counterweight of the operation vehicle is increased; the Y-shaped jack auxiliary retraction device is designed to facilitate retraction; the external hanging box of the generator is added, so that the generator is lifted out and retracted more practically, quickly and conveniently, and the safety is higher. However, due to the large volume of the whole vehicle, the operating room is difficult to get in place under the condition of traffic interruption and extremely bad road conditions, and the optimal treatment time of wounded persons can be delayed.

Therefore, a field operation bed with high expansibility, small occupied area and convenient carrying is designed, and a large demand space exists.

Therefore, the inventor designs a field operation table capable of providing multi-position support for a patient, for solving the above problems.

Disclosure of Invention

(one) solving the technical problems

The utility model aims to overcome the defects in the prior art and provide a field operation table capable of providing multi-position support for patients.

(II) technical scheme

A field operation table capable of providing multi-position support for patients comprises an outer frame, a bed plate, a support component and a deflection component;

the periphery of the outer frame is provided with a plurality of handles for carrying; the middle part of the outer frame is provided with a through mounting groove, and the bed board is rotatably arranged in the mounting groove; the outer frame is provided with a deflection assembly which is used for adjusting the deflection angle of the bed board; the bottom surface of the outer frame is provided with a containing seat, and the containing seat is hollow and the bottom is provided with an outlet; the support component is arranged in the storage seat, and can prop up the outer frame and the bed plate when the support component stretches out of the storage seat.

Preferably, the deflection assembly comprises a main shaft, a worm wheel, a worm and a driving shaft;

the outer frame is of a hollow structure, and a cavity is formed in the outer frame; the head end and the tail end of the bed board are connected with coaxial spindles, the spindles extend into the cavity, at least one spindle is provided with a worm wheel, the worm wheel is meshed with a worm, and the worm is connected to the driving shaft; the worm wheel and the worm can realize self-locking; a supporting plate is arranged in the cavity, the driving shaft penetrates through and rotates to be connected with the supporting plate, and the outer end of at least one driving shaft extends out of the outer frame and is connected with a first hand wheel.

Preferably, the two main shafts are provided with worm wheels, the two driving shafts are correspondingly provided with first transmission wheel sets, and the first transmission wheel sets are in transmission connection through a first transmission belt; the worm wheels on both sides turn the same.

Preferably, the support component comprises an adjusting shaft, a movable nut, a push-pull rod and a deflection rod;

the adjusting shaft is rotatably arranged in the storage seat, and two sections of threads with opposite rotation directions are symmetrically arranged on the adjusting shaft and are respectively connected with a movable nut in a threaded manner; the deflection rods are also symmetrically arranged and are close to the outlet of the storage seat; one end of the deflection rod is hinged with the inner wall of the storage seat, one end of the push-pull rod is hinged with the movable nut, and the other end of the push-pull rod is hinged with the deflection rod; one end of at least one adjusting shaft also extends out of the storage seat and is provided with a second hand wheel.

Preferably, the two adjusting shafts extend out of the storage seat and are correspondingly provided with a second transmission wheel set, and the second transmission wheel sets are in transmission connection through a second transmission belt.

Preferably, the other end of the deflection rod is also detachably provided with a roller; the top of the idler wheel is provided with a thread installation handle, the other end of the deflection rod is provided with a thread installation hole, and the thread installation handle is in threaded connection with the thread installation hole.

Preferably, the push-pull rod is divided into two screws with opposite rotation directions, and the two screws are connected through a thread sleeve.

Preferably, the head part of the bed board is provided with a first storage groove, and the first storage groove is provided with a back plate; the tail end of the backboard is hinged to the tail end of the first storage groove, a groove is formed in the bottom surface of the backboard, a supporting rod is arranged in the groove, the head end of the supporting rod is hinged to the head end of the groove, and a plurality of clamping blocks are arranged at intervals in the inner bottom of the first storage groove, corresponding to the tail end of the supporting rod; the backboard can be completely accommodated in the first accommodating groove.

Preferably, the tail part of the bed board is also provided with a second containing groove, and a first plate and a second plate are arranged in the second containing groove; the head end of the first plate is hinged with the head end of the second storage groove, and the tail end of the first plate is hinged with the head end of the second plate; the tail end of the second plate is symmetrically hinged with a clamping head which is provided with clamping teeth; racks are arranged at bottoms of the second storage grooves corresponding to the clamping teeth; the first plate and the second plate can be completely contained in the second containing groove.

Preferably, the first limiting block which rotates is arranged at the head part of the first storage groove corresponding to the bed plate, and the first limiting block is eccentrically arranged and can cover the first storage groove and press the back plate in the first storage groove when rotating; the bed board is provided with pivoted No. two stoppers corresponding to No. two storage tank afterbody, and No. two stoppers also eccentric setting can cover No. two storage tanks and press No. two boards in No. two storage tanks when rotating.

(III) beneficial effects

The utility model provides a field operation table capable of providing multi-position support for patients, which has the following advantages:

1, adopting the design of an outer frame and a rotary bed board, through arranging a deflection assembly in a hollow cavity of the outer frame, a driving shaft is rotated by a number one hand, and the driving shaft drives a worm wheel to rotate along with a worm, so that a main shaft drives the bed board to deflect, and the operation angle is adjusted. And because the worm wheel and the worm adopt self-locking type, the bed plate can be positioned, and the self-rotation is avoided.

2, a hollow storage seat is arranged on the bottom surface of the outer frame and is provided with a supporting component, the adjusting shaft is rotated by two numbers of hands, and based on the action of threads, the movable nuts are enabled to be close to or far away from each other, so that the deflecting rod is driven to deflect by the push-pull rod; the deflection rod deflects out of the storage seat to support the whole operating table, and meanwhile, the height of the operating table can be adjusted, so that a wounded can lie down conveniently; the deflection rod deflects into the storage seat to realize complete storage, so that the space occupation is reduced.

And 3, in addition, the other end of the deflection rod is detachably provided with a roller, and the roller can be arranged on the deflection rod according to the requirement, so that the whole movement of the operating table is facilitated. The push-pull rod is divided into two screws with opposite rotation directions, and the two screws are connected through a thread sleeve; the two screws can be mutually close to or far away from each other by rotating the threaded sleeve, so that the whole length of the push-pull rod is changed, the supporting angle of the deflection rod is changed, and the operating table leveling device is suitable for leveling an operating table on uneven ground.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only of the present utility model, protecting some embodiments, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a side view of the present utility model;

FIG. 2 is a top view of the present utility model;

FIG. 3 is a bottom view of the present utility model;

FIG. 4 is a block diagram of one state of the bed deck;

FIG. 5 is a view showing the structure of another state of the bed plate;

FIG. 6 is a top view of another embodiment of the present utility model;

FIG. 7 is a block diagram of a push-pull member;

in the drawings, the list of components represented by the various numbers is as follows:

101-an outer frame, 102-a cavity, 103-a bed board, 104-a storage seat, 105-a first storage groove and 106-a second storage groove;

201-a main shaft, 202-a worm wheel, 203-a worm, 204-a driving shaft, 205-a first hand wheel, 206-a first transmission wheel set, 207-a first transmission belt and 208-a supporting plate;

301-an adjusting shaft, 302-a movable nut, 303-a push-pull rod, 3031-a screw rod, 3032-a threaded sleeve, 304-a deflection rod, 305-a roller, 306-a No. two hand wheel, 307-a No. two transmission wheel set, 308-a No. two transmission belt and 309-a threaded mounting handle;

401-back plate, 402-groove, 403-strut, 404-fixture block, 405-first limiting block;

501-first plate, 502-second plate, 503-chuck, 504-latch, 505-rack, 506-second stopper.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that, if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like are used, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, only for convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the indicated apparatus or element must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," "third," and the like, as used herein, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that unless explicitly specified and limited otherwise, terms such as "mounted," "connected," and "connected" are to be construed broadly and include, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Example 1

Referring to fig. 1, 2 and 3, a field operation table capable of providing multi-position support for a patient comprises an outer frame 101, a bed plate 103, a support assembly and a deflection assembly;

the periphery of the outer frame 101 is provided with a plurality of handles for carrying; the middle part of the outer frame 101 is provided with a through mounting groove, and the bed plate 103 is rotatably arranged in the mounting groove; the outer frame 101 is provided with a deflection assembly, and the deflection assembly is used for adjusting the deflection angle of the bed plate 103; the bottom surface of the outer frame 101 is provided with a containing seat 104, and the containing seat 104 is hollow and the bottom is provided with an outlet; the accommodating seat 104 is internally provided with a supporting component, and when the supporting component extends out of the accommodating seat 104, the outer frame 101 and the bed plate 103 can be supported.

Example 2

Referring to fig. 1, the deflection assembly includes a main shaft 201, a worm wheel 202, a worm 203, and a drive shaft 204;

the outer frame 101 is of a hollow structure, and a cavity 102 is formed in the outer frame; the head end and the tail end of the bed plate 103 are connected with coaxial spindles 201, the spindles 201 extend into the cavity 102, at least one spindle 201 is provided with a worm wheel 202, the worm wheel 202 is meshed with a worm 203, and the worm 203 is connected to a driving shaft 204; a support plate 208 is connected to the cavity 102, the drive shaft 204 penetrates through and rotates to connect with the support plate 208, and the outer end of at least one drive shaft 204 extends out of the outer frame 101 and is connected with a first hand wheel 205.

Referring to fig. 2, the support assembly includes an adjustment shaft 301, a traveling nut 302, a push-pull rod 303, and a deflection rod 304;

the adjusting shaft 301 is rotatably installed in the accommodating seat 104, and two sections of threads with opposite rotation directions are symmetrically processed on the adjusting shaft 301 and are respectively and spirally connected with the movable nut 302; the deflection bars 304 are also symmetrically disposed and disposed proximate the outlet of the receptacle 104; one end of the deflection rod 304 is hinged with the inner wall of the storage seat 104, one end of the push-pull rod 303 is hinged with the movable nut 302, and the other end of the push-pull rod is hinged with the deflection rod 304; one end of at least one adjusting shaft 301 also extends out of the accommodating seat 104 and is provided with a second hand wheel 306.

The following describes the method of using the present operating table, taking the present embodiment as an example:

the second hand wheel 306 rotates the adjusting shaft 301, and the moving nuts 302 are moved close to or away from each other based on the screw thread effect, so that the push-pull rod 303 drives the deflection rod 304 to deflect; the deflection rod 304 deflects the storage seat 104 to support the whole operating table, and the height of the operating table can be adjusted, so that a wounded can lie down; the deflection rod 104 deflects into the accommodating seat 104 to realize complete accommodating, so that the space occupation is reduced;

the driving shaft 204 is rotated by the first hand wheel 205, and then the driving shaft 204 enables the worm 203 to drive the worm wheel 202 to rotate, so that the main shaft 202 deflects along with the bed plate 103, and the operation angle is adjusted. The worm wheel 202 and the worm 203 can be self-locked, so that the bed plate 103 can be positioned, and the self-rotation is avoided;

in addition, referring to fig. 1, 2 and 3, two main shafts 201 are respectively provided with a worm wheel 202, two driving shafts 204 are correspondingly provided with a first transmission wheel set 206, and the first transmission wheel sets 206 are in transmission connection through a first transmission belt 207; the worm gears 202 on the two sides turn the same direction, so that synchronous work of the worm gears 202 at the head and the tail can be realized only by rotating one driving shaft 204, thereby improving the deflection stability of the bed plate 103;

similarly, the two adjusting shafts 301 extend out of the storage seat 104 and are correspondingly provided with the second transmission wheel set 307, and the second transmission wheel sets 307 are in transmission connection through the second transmission belt 308, so that the two groups of support components can synchronously work by only rotating one adjusting shaft 301, and four legs of the operating table can synchronously open and support.

Example 3

This example was used in the same manner as example 2.

Referring to fig. 7, the other end of the deflection rod 304 is also detachably provided with a roller 305, specifically, the top of the roller 305 is connected with a threaded mounting handle 309, the other end of the deflection rod 304 is processed with a threaded mounting hole, and the threaded mounting handle 309 is screwed with the threaded mounting hole.

In this way, the roller 305 can be mounted on the deflection rod 304 as required, which facilitates the overall movement of the operating table.

In addition, the push-pull rod 303 is divided into two screw rods 3031 with opposite rotation directions, and the two screw rods are connected through a threaded sleeve 3032; the two screws 3031 can be mutually close to or far away from each other by rotating the threaded sleeve 303, so that the overall length of the push-pull rod 303 is changed, the supporting angle of the deflection rod 304 is changed, and the operating table leveling device is suitable for leveling an operating table on uneven ground.

Example 4

On the basis of the above-described embodiments,

referring to fig. 4, a first receiving groove 105 is formed in the head of the bed plate 103, and the first receiving groove 105 is provided with a back plate 401; specifically, the tail end of the backboard 401 is hinged to the tail end of the first storage groove 105, a groove 402 is formed in the bottom surface of the backboard 401, a supporting rod 403 is arranged in the groove 402, the head end of the supporting rod 403 is hinged to the head end of the groove 402, and a plurality of clamping blocks 404 which are spaced are machined at intervals at the inner bottom of the first storage groove 105 and correspond to the tail end of the supporting rod 403;

as shown in fig. 4, the back plate 401 may be completely accommodated in the first accommodating groove 105; as shown in fig. 5, the back plate 401 can rotate around the tail end, and the supporting rod 403 can rotate around the head end, so that the tail end of the supporting rod 403 props against the clamping block 404 to form a stable triangle support, thereby supporting the back plate 401 and supporting the back of the patient; the intermittent design of the multiple clamping blocks 404 also facilitates the adjustment of the angle of the back plate 401.

The tail part of the bed plate 103 is also provided with a second containing groove 106, and a first plate 501 and a second plate 502 are arranged in the second containing groove 106; specifically, the head end of the first plate 501 is hinged to the head end of the second storage groove 106, and the tail end of the first plate 502 is hinged to the head end of the second storage groove 106; the tail end of the second plate 502 is symmetrically hinged with a clamping head 503, and the clamping head 503 is provided with clamping teeth 504; a rack 505 is fixed at the bottom of the second storage groove 106 corresponding to the latch 504;

similarly, as shown in fig. 4, the first plate 501 and the second plate 502 can be completely accommodated in the second accommodating groove 106; as shown in fig. 5, a first plate 501 and a second plate 502 form a bending piece, a clamping head 503 at the tail end of the first plate 501 is clamped and fixed with a rack 505 through a clamping tooth 504, so that the bending piece can prop up a wounded lower limb, and a knee is positioned at the joint of the two plates; similarly, the clamping position of the clamping teeth 504 and the racks 505 is adjustable, and the bending angle of the bending piece is changed, so that the bending degree of the lower limb is adjusted.

In addition, the back plate 401 can be completely accommodated in the first accommodating groove 105, and the first plate 501 and the second plate 502 can be completely accommodated in the second accommodating groove 106, but the back plate is still easy to scratch out during transportation; therefore, referring to fig. 6, the first stopper 405 is installed at the head of the first receiving slot 105 and is rotated, the first stopper 405 is eccentrically disposed, and when the long side of the first stopper rotates to the first receiving slot 105, the first receiving slot 105 can be covered, so that the backboard 401 is pressed in the first receiving slot 105, and after the long side of the first stopper rotates, the first receiving slot 105 is not blocked, so that the backboard 401 can be adjusted;

similarly, the bed board 103 is provided with a second rotating limiting block 506 corresponding to the tail of the second containing groove 106, the second limiting block 506 is also eccentrically arranged, and the long side of the second limiting block 506 rotates to the second containing groove 106 to cover the second containing groove 106, so that the second board 502 is pressed in the second containing groove 106, and after the long side of the second limiting block rotates, the second containing groove 106 is not blocked, and therefore the first board 501 and the second board 502 can be adjusted.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the utility model disclosed above are intended only to assist in the explanation of the utility model. The preferred embodiments are not intended to be exhaustive or to limit the utility model to the precise form disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the utility model and the practical application, to thereby enable others skilled in the art to best understand and utilize the utility model. The utility model is limited only by the claims and the full scope and equivalents thereof.

Claims

1. The field operation bed capable of providing multi-position support for patients is characterized by comprising an outer frame (101), a bed plate (103), a support assembly and a deflection assembly; the periphery of the outer frame (101) is provided with a plurality of handles for carrying; the middle part of the outer frame (101) is provided with a through mounting groove, and the bed plate (103) is rotatably arranged in the mounting groove; the outer frame (101) is provided with a deflection assembly, and the deflection assembly is used for adjusting the deflection angle of the bed plate (103); the bottom surface of the outer frame (101) is provided with a containing seat (104), and the containing seat (104) is hollow and the bottom is provided with an outlet; a supporting component is arranged in the storage seat (104), and when the supporting component extends out of the storage seat (104), the outer frame (101) and the bed plate (103) can be supported;

the deflection assembly comprises a main shaft (201), a worm wheel (202), a worm (203) and a driving shaft (204); the outer frame (101) is of a hollow structure, and a cavity (102) is formed in the outer frame; the two ends of the head and tail of the bed plate (103) are connected with coaxial shafts (201), the shafts (201) extend into the cavity (102), at least one of the shafts (201) is provided with a worm wheel (202), the worm wheel (202) is meshed with a worm (203), and the worm (203) is connected to a driving shaft (204); the worm wheel (202) and the worm (203) can realize self-locking; a supporting plate (208) is arranged in the cavity (102), the driving shaft (204) penetrates through and is rotationally connected with the supporting plate (208), and the outer end of at least one driving shaft (204) extends out of the outer frame (101) and is connected with a first hand wheel (205); the two main shafts (201) are provided with worm wheels (202), the two driving shafts (204) are correspondingly provided with first transmission wheel sets (206), and the first transmission wheel sets (206) are in transmission connection through a first transmission belt (207); the worm wheels (202) on the two sides turn the same;

the support assembly comprises an adjusting shaft (301), a moving nut (302), a push-pull rod (303) and a deflection rod (304); the adjusting shaft (301) is rotatably arranged in the storage seat (104), two sections of threads with opposite rotation directions are symmetrically arranged on the adjusting shaft (301), and the two sections of threads are respectively connected with the movable nut (302) in a threaded manner; the deflection rods (304) are also symmetrically arranged and are arranged close to the outlet of the storage seat (104); one end of the deflection rod (304) is hinged with the inner wall of the storage seat (104), one end of the push-pull rod (303) is hinged with the movable nut (302), and the other end of the push-pull rod is hinged with the deflection rod (304); one end of at least one adjusting shaft (301) also extends out of the containing seat (104) and is provided with a second hand wheel (306); the push-pull rod (303) is divided into two screws (3031) with opposite rotation directions, and the screws are connected through a thread sleeve (3032).

2. The field operation table capable of providing multi-position support for patients according to claim 1, wherein the two adjusting shafts (301) extend out of the storage seat (104) and are correspondingly provided with a second transmission wheel set (307), and the second transmission wheel sets (307) are in transmission connection through a second transmission belt (308).

3. A field operation table capable of providing multi-position support for a patient according to claim 1, wherein the other end of the deflection rod (304) is also detachably provided with a roller (305); a threaded mounting handle (309) is arranged at the top of the roller (305), a threaded mounting hole is formed in the other end of the deflection rod (304), and the threaded mounting handle (309) is in threaded connection with the threaded mounting hole.

4. The field operation table capable of providing multi-position support for patients according to claim 1, wherein the head of the bed plate (103) is provided with a first storage groove (105), and the first storage groove (105) is provided with a backboard (401); the tail end of the backboard (401) is hinged to the tail end of the first storage groove (105), a groove (402) is formed in the bottom surface of the backboard (401), a supporting rod (403) is arranged in the groove (402), the head end of the supporting rod (403) is hinged to the head end of the groove (402), and a plurality of clamping blocks (404) are arranged at intervals in the first storage groove (105) corresponding to the tail end of the supporting rod (403); the backboard (401) can be completely contained in the first containing groove (105).

5. The field operation table capable of providing multi-position support for patients according to claim 4, wherein a second containing groove (106) is further formed at the tail of the bed plate (103), and a first plate (501) and a second plate (502) are arranged in the second containing groove (106); the head end of the first plate (501) is hinged to the head end of the second storage groove (106), and the tail end of the first plate is hinged to the head end of the second plate (502); the tail end of the second plate (502) is symmetrically hinged with a clamping head (503), and the clamping head (503) is provided with clamping teeth (504); a rack (505) is arranged at the inner bottom of the second storage groove (106) corresponding to the latch (504); the first plate (501) and the second plate (502) can be completely contained in the second containing groove (106).

6. The field operation table capable of providing multi-position support for patients according to claim 5, wherein the bed board (103) is provided with a rotary first limiting block (405) corresponding to the head of the first storage groove (105), and the first limiting block (405) is eccentrically arranged and can cover the first storage groove (105) and press the backboard (401) in the first storage groove (105) when rotating; the bed board (103) is provided with a rotary second limiting block (506) corresponding to the tail part of the second storage groove (106), and the second limiting block (506) is eccentrically arranged and can cover the second storage groove (106) and press the second board (502) in the second storage groove (106) when rotating.