SUPPORT APPARATUS WITH HEIGHT ADJUSTMENT

Abstract

The present invention relates to a support apparatus with height adjustment, which comprises a first body, and a second body mounted with a sliding way and axially connected to a tenon of the first body; therein, the tenon is used to selectively control the upward or downward sliding of the second body with a button co-operated with the tenon; a spring restrains the second plate body and the tenon so that the tenon selects the direction of vertical upward/downward motion of the second body.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a support apparatus with height adjustment, particularly to a selecting structure which is used to control the forward/downward motion, specially applied for adjusting the stature of a liquid crystal display device.

2. Description of the Prior Art

A traditional support apparatus for height adjustment of a liquid crystal display (LCD) is a kind of mechanism for lifting up/lowering and is applied to all kinds of apparatus with the need of adjusting stature. In particular, the present invention concerns a supporting structure of a liquid crystal display (LCD) device in the contemporary market.

An open loop linkage structure is usually used as legs to support a liquid crystal display device, and the purpose of adjusting the stature of the liquid crystal display device is achieved by adjusting the angle of linkage about an axis. Therein, a liquid crystal display is axially connected to a terminal lever of the linkage structure by adjusting the angle of the liquid crystal display device about the axis. Thus, the displaying direction of the LCD screen is changed. For the need of supporting the weight of the open loop linkage, a rotating resistance of each pivot of linkage increases. Thus, inconvenience of adjusting the rotating angle appears.

According to the foregoing reasons, disadvantages of traditional techniques used for operating a raising/lowering apparatus are improved.

SUMMARY OF THE INVENTION

According to a support apparatus with height adjustment of the present invention, a structure used for selecting the up/down motion is provided.

In another purpose according to the present invention, a first body is used to guide a second body and the up/down sliding motion of the second body is selectively controlled by a tenon to avoid disadvantages of the open loop structure.

In yet another purpose according to present invention, adjusting the stature of LCD screen is achieved with a simple structure.

Based on the purposes described above, a second body is installed in a first body of the support apparatus according to the present invention with a sliding way.

The second body is guided in a guiding part defined by an inner space of the first body and is selected an upward and a downward motion by a button which drives a tenon working between a first state and a second state. A spring is respectively connected to the second body and the tenon at two ends of the spring for selecting vertical upward/downward motion of the second body. Furthermore, a LCD screen is located upon the top of the second body.

The objects, feature, and effect of the present invention will be more readily understood from the following detailed description of the preferred embodiments with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded perspective view of a support apparatus with height adjustment of the first preferred embodiment according to the present invention;

FIG. 2 shows a local cutaway view of the tenon of a support apparatus with height adjustment according to the present invention; therein the tenon is at the first state;

FIG. 3 shows a local cutaway view of the tenon of a support apparatus with height adjustment according to the present invention; therein the tenon is at the second state;

FIG. 4 shows a local cutaway view of the tenon of a support apparatus with height adjustment after coming down according to the present invention; therein the tenon is back to the first state;

FIG. 5 shows an exploded perspective view of a support apparatus with height adjustment of the second preferred embodiment according to the present invention;

FIG. 6 shows a local cutaway view of the damping device in FIG. 5 according to the present invention; therein the tenon is at the first position;

FIG. 7 shows a local cutaway view of the damping device in FIG. 5 according to the present invention; therein the tenon is at the second position;

FIG. 8 shows a side view of a support apparatus with height adjustment of the third preferred embodiment according to the present invention; therein the tenon is at the first state;

FIG. 9 shows an exploded perspective view of a support apparatus with height adjustment of the fourth preferred embodiment according to the present invention;

FIG. 10 shows a cutaway view of a support apparatus with height adjustment of the fourth preferred embodiment according to the present invention;

FIG. 11 shows a cutaway view of a support apparatus with height adjustment of another type of the fourth preferred embodiment according to the present invention.

FIG. 12 is a sectional view of a partial of a support apparatus with height adjustment according to the present invention;

FIG. 13 is a sectional view of a support apparatus with height adjustment of the fifth preferred embodiment according to the present invention; according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following is a description of the present invention. The invention will firstly be described with reference to one exemplary structure. Some variations will then be described as slot as with the advantages of the present invention. A preferred method of fabrication will then be discussed. An alternate, asymmetric embodiment will then be described along with the variations in the process flow to fabricate this embodiment.

Referring to FIG. 1, a support apparatus with height adjustment primarily comprises a first body 1, a second body 2, and a tenon 3. Therein, the first body 1 includes a first plate body 11, a second plate body 12 and a structure body constructed by a guiding part 13 defined by two plate bodies formed of a first plate body 11 and a second plate body 12; the first plate body 11 has voided part 11 a which penetrates and fits the tenon 3; the second plate body 12 has a button 12a, which co-operates with the tenon 3 and penetrates and slides in a confined manner on the second plate body 12; and the guiding part 13 has two parallel surfaces and is used to mount and slide on the second body 2.

Additionally, the second body 2, which is a plate body and is installed into the guiding part 13 of the first body 1 with vertically up/down sliding method, includes a vertically extending rectangular hole 21 and a plurality of slots 22 arranged along the rectangular hole 21.

Furthermore, the tenon 3, which is axially mounted on a voided part 11a of the first plate body 11, has a top part 31 formed on the top of the tenon 3, and an under flange 32 formed on one surface of bottom of the tenon 3 so as to selectively be locked in a slot 22 of the second body 2; therein, a button 12a of the second plate body 12 is mutually co-operating; a spring Is set and respectively connected to the second plate body 12 and the tenon 3 at two ends so as to provide an elastic force to maintain the tenon tending to a first state, and to limit the tenon reaching a second state by operating the button 12a; so the tenon 3 becomes a structure for selecting vertically upward or downward motion of the second body 2, and the button 12a is operated in coordination with rectangular hole 21, so no mechanical interference is produced by the button 12a and the first plate body 11.

FIG. 2 shows a local cutaway view of the tenon 3 of a support apparatus with height adjustment according to the present invention; therein the tenon 3 is at the first state; FIG. 3 shows a local cutaway view of the tenon of a support apparatus with height adjustment according to the present invention; therein the tenon 3 is at the second state; FIG. 4 shows a local cutaway view of the tenon 3 of a support apparatus with height adjustment after descending according to the present invention; therein the tenon 3 is back to the first state.

Referring to FIG. 2, FIG. 3 and FIG. 4, according to the embodiment of the present invention, partial elements for carrying out and the achievement of the operating mechanism will be explained as the following.

According to the present invention, the tenon 3 is axially mounted on the voided part 11a with an axis 34; a spring 33 is connected to the top of the axis 34 at one end, and connected to the top of the button 12a of the second plate body 12 at the other end. Thus, the tenon 3 is at the first state, as the spring 33 is at the position of a balanced state; the top part 31 is separate from the slot 22 of the second body 2; the under flange 32 is interfered with the slot 22 of the second body 2. The tenon 3 is at the second state as pressing the button 12a, and elastic force in an opposite direction is produced from the pressure; the under flange 32 is separated from the slot 22 of the second body 2, and the under flange 32 is interfered with the slot 22 of the second body 2.

Besides, a height difference between the position of the top part 31 and the position of the under flange 32 of the tenon 3 must be greater than or equal to N times the interval of the slots 22 on the second body 2, but smaller than or equal to M times the interval of the slots 22 of the second body 2, therein M is greater than N.

Referring to FIG. 2, according to the embodiment of the present invention, a height difference between top part 31 and under flange 32 of the tenon 3 is greater than adding a multiple of the central distance and the interval distance between slots 22 of the second body 2, but smaller than or equal to twice the central distance between slots 22 of the second body 2.

Referring to FIG. 3, the tenon 3 will change into the second state as pushing the button 12a of the second plate body 12, so the under flange 32 of the tenon 3 will exit the first slot 22a; however, the top part 31 of the tenon 3 is interfered with the third slot 22c until the second body 2 descends along the guiding part 13 of the first body 1, down to the top of the third slot 22c and stops at the top part 31 of the tenon 3.

Referring to FIG. 4, the tenon 3 returns to the first state as releasing the button 12a of the second plate body 12. Thus the top part 31 of the tenon 3 exits the third slot 22c, but the under flange 32 is interfered with the second slot 22b until the second body 2 descends to the second slot 22b and stops at the under flange 32 of the tenon 3.

Therefore, the tenon 3 is changed from the first state to the second state; after going back to the first state, the second body 2 along the guiding part 13 of the first body 1 descends one unit central distance between the second body; pressing the button 12a of the second plate body 12 once, and it descends one unit distance.

FIG. 5 shows an exploded perspective view of a support apparatus with height adjustment of the second preferred embodiment according to the present invention; FIG. 6 shows a local cutaway view of the damping device in FIG. 5 according to the present invention; therein the tenon is at the first position; FIG. 7 shows a local cutaway view of the damping device in FIG. 5 according to the present invention; therein the tenon is at the second position.

Referring to FIGS.5, 6 and 7, according to the embodiment of the present invention described above, a damping device 23 is set to provide damping force for the second body 2 during the descending process, so as to slow down the descending speed of the second body 2 for stabilizing descending of the damping device 23. According to another preferred embodiment, the damping device is set into the second body 2, and constructed by a damping slot 231 and damping block 232 with mutual cooperation. Therein, the damping slot 231 is formed by caving in an inside surface of the second body 2, and the opening of the damping slot is formed to face to the first plate body 11; a damping block 232 is located at the bottom of the damping slot 231; a damping block 232 is set inside the damping slot 231 with a vertically sliding way, and a cuneal part 232a is formed and fitted on the top of the damping slot 231; as the cuneal part 232a of the damping block 232 is connected Into the damping slot 231 of the cuneal part 232a, contact forward force between the damping block 232 and the first plate body 11 increases.

Additionally, an elastic element 233 is set to connect both the damping slot 231 and the damping block 232 of the damping device 23; the damping block 232 tends to go back to the first position.

Referring to FIG. 6, in accordance with the second embodiment of the present invention, as the second body 2 and the guiding part 13 of the first body 1 are relatively static, the damping slot 231 and damping block 232 of the damping device 23 of the second body 2 are located at the first position; because contact force between cuneal slot 231a of the damping slot 231 and the damping block 232 of the cuneal part 232a is smaller, forward contact force between the damping block 232 and first plate body 11 is smaller; friction between the damping block 232 and the first plate body 11 is also smaller; the friction also takes place as the second body 2 rises relatively compared to the guiding part 13 of the first body 1.

Referring to FIG. 7, as the second body 2 descends relatively compared to the guiding part 13 of the first body 1, the damping block 232 is drawn back because of friction of the first plate body 11 and moves up along the cuneal slot 231a of the damping slot 231 with the resisting elastic element 233; and gradually increasing contact force between the damping 231a of the damping slot 231 and the cuneal part 232a of the damping block 232 occurs, until the damping slot 231 and the damping block 232 of the damping device 23 of second body 2 is located at the second position. Therefore, the forward contact force between the damping block 232 and the first plate body 11 is greater; friction between the damping block 232 and first plate body 11 is also greater; and the descending acceleration of the second body 2 will be slowed down to achieve the effect of a buffer.

FIG. 8 shows a cutaway view of a support apparatus with height adjustment of the third preferred embodiment according to present invention; a coupling stage 4 and a leg 5 are added to locate a LCD screen 6; therein, the coupling stage 4 is mounted on the top of the second body 2; and the shackle 41 structure is formed on top; the leg 5 is the supporting structure mounted on bottom of the first body 1 and is used to support and maintain balance of the whole support apparatus with height adjustment and the LCD screen 6; the LCD screen 6 is axially connected to the coupling stage 4; therefore, direction of the LCD screen is changed by the axial structure of the coupling stage 4; and the height of the screen is changeable by a relative motion of the second body 2 and the first body 1.

Referring to FIG. 9 and FIG. 10, a support apparatus with height adjustment of the present invention is modified as the prior embodiment and primarily comprises a first body 91, a second body 92, and a tenon 93. The first body 91 is a hollow shell structure, and a part of inner surface thereof surrounds and forms a space which is extending axially and is defined a guiding part that can be divided surface thereof into a first surface 911 and a second surface 912 at least. The second body 92 is a bulk structure which has an outline according to the guiding part 913, and the second body 92 is installed and guided in the guiding part 913. Corresponding to the first surface 911 of the guiding part 913, a surface of the second body 92 has plurality of concave slots 921, and the slots 921 are arranged along the axial of the guiding part 913. The tenon 93 is pivoted at the first body 91 and is corresponded to a space 914 opened on the first surface 911. Corresponding to the first surface 911 of the guiding part 913, the tenon 93 pivoted at the first body 91 has a top part 931 on the top and an under flange 932 at the bottom, and the top part 931 and the under flange 932 are used alternatively to engage a corresponding slot 921 of the second body 92. Corresponding to the tenon 93, a spring 933 is installed to limit the tenon 93 between a first state and a second state. A button 934 installed in the first body 91 is restrained between a first position and a second position by an elastic structure and intended to an initial position under no external force. The first position of the button 934 is the initial position, and the second position is that the button 934 pressed by the external force is reached. By operating the button 934, one of the first state and the second state of the tenon 93 is chosen.

In the support apparatus with height adjustment as former paragraph, the second surface 912 of the first body 91 has a guiding rib 915 and a surface of the second body 92 corresponding to the second surface 912 has a sliding-track 922 respectively. The sliding-track 922 is corresponded to the guiding rib 915 and is concave and extended along the axial of the guiding part 913 while the guiding rib 915 is convex and extended along the axial of the guiding part 913. The guiding rib 915 and the sliding-track 922 lead the first body 91 and the second body 92 to move along the axial of the guiding rib 915 relatively.

A first body 91 is a cylinder structure, and some surface surrounds and forms a space which is extending axially and is defined a guiding part that can be divided surface thereof into a first surface 911 and a second surface 912 at least. A second body 92 is a cylinder structure which is installed and guided in the guiding part 913. Corresponding to the first surface 911 of the guiding part 931a surface of the second body 92 has plurality of concave slots 921, and the slots 921 are arranged along the axial of the guiding part 913. A tenon 93 is pivoted at the first body 91 and is corresponded to a space 914 opened on the first surface 911. Corresponding to the first surface 911 of the guiding part 913, the tenon 93 has a top part 931 on the top and an under flange 932 at the bottom, and the top part 931 and the under flange 932 are used alternatively to engage a corresponding slot 921 of the second body 92. Corresponding to the tenon 93, a spring 933 is installed to limit the tenon 93 between a first state and a second state. A button 934 installed in the first body 91 is restrained between a first position and a second position by an elastic structure and intended to an initial position under no external force. The first position of the button 934 is the initial position, and the second position is that the button 934 pressed by the external force is reached. By operating the button 934, one of the first state and the second state of the tenon 93 is chosen.

The elastic structure which restrains the button 934 is a beam 935 installed in the first body 91, and the beam 935 has a designed elastic deformation range which the button 934 reaches the second state with an external force while the button 934 reaches the first state without the external force.

Referring to FIG. 11, the tenon 93 is pivoted at the first body 91 by a pivot 93a. A buck 932′ is pivoted at a lower arm of the tenon 93 by a pivot 932a and forms the said under flange 932 at upper arm thereof while a lower arm of the buck 932′ is pivoted at the first body 91 by a pivot 932b. The said button 934 is installed in the first body 91 and is corresponding to the under flange 932. Therefore, one of the first state and the second state of the tenon 93 is chosen by the operating of the button 934. Pressing the button 934 to contact the buck 932′ corresponding to the under flange 932 can choose the tenon 93 into the second state while the buck 932′ rotates about the pivot 932b and brings the pivot 932a to make tenon 93 rotate about the pivot 93a and release the slots 921 of the second body 92. At the same time, the second body 92 moves down and the under flange 932 interferes the slots 921 of the second body 92 immediately to stop the second body 92 moving. After that, releasing the button 934 can choose the tenon 93 into the first state while the buck 932′ rotates about the pivot 932b to release the slots 921 and brings the pivot 932a to make tenon 93 rotate about the pivot 93a and interfere the slots 921 of the second body 92 again.

Referring to FIG. 12, a frame 94 is installed at the first body 91 to form the space 914, and the frame 94 is restricted at the first body 91 but has a vertical freedom to allow vertical movement thereof. A buffer 95 is installed under the frame 94, and the buffer 95 is contacted to a protrusion 917 of the first body 91 for being a buffer to absorb an impact caused by the second body 92. Therefore, when the first body 91 and the second body 92 move relatively, the impact caused by the second body 92 is absorbed by the buffer 95. At this reason, the buffer 95 is selected from rubber, spring or any buffer materials.

Referring to FIG. 13, this embodiment is based on the embodiment showed as FIG. 11. The spring 933 is still limited the tenon 93 between a first state and a second state, and the tenon 93 and the buck 932′ are worked as prior embodiment even though the embodiment showed as FIG. 13 has different configuration. The particular is that the buck 932′ has a leaf spring 932c corresponding to the button 934. Therefore, pressing the button 934 to contact the leaf spring 932c of the buck 932′ and the tenon 93 can choose the tenon 93 into the second state while the leaf spring 932c transmits the force produced by the button 934 to push the buck 932′ to rotate about the pivot 932b and to make tenon 93 rotate about the pivot 93a to release the slots 921 of the second body 92. At the same time, the second body 92 moves down and the under flange 932 interferes the slots 921 of the second body 92 immediately to stop the second body 92 moving. After that, releasing the button 934 can choose the tenon 93 into the first state while the buck 932′ rotates about the pivot 932b to release the slots 921 and brings the pivot 932a to make tenon 93 rotate about the pivot 93a and interfere the slots 921 of the second body 92 again.

Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims.

Claims

1. A support apparatus with height adjustment, comprising:

a first body, which is a hollow shell structure and a part of inner surface thereof defines a space which is extending as a guiding part;

a second body, which is a bulk structure installed and guided in the guiding part and a surface thereof has plurality of concave slots which are arranged along the axial of the guiding part and corresponding to the first surface of the guiding part;

a tenon, which is pivoted at the first body and is corresponded to the space opened on the first surface, and which has a top part on the top and an under flange at the bottom corresponding to the first surface of the guiding part and the top part and the under flange are used alternatively to engage a corresponding slot of the second body;

a spring, which is installed to limit the tenon between a first state and a second state; and a button, which is installed in the first body and is restrained between a first position and a second position by an elastic structure;

wherein which the first state and the second state of the tenon is done is chosen by operating the button.

2. The support apparatus with height adjustment as recited in claimed 1, wherein the first body is a structure body constructed by a first plate body and a second plate body which defined an inner space as the guiding part.

3. The support apparatus with height adjustment as recited in claimed 2, wherein the second body is a plate body and is installed into the guiding part of said first body with a vertically up/down sliding way.

4. The support apparatus with height adjustment as recited in claimed 3, wherein the second body includes a rectangular hole which extends vertically and has a plurality of slots ranked along the rectangular hole; and the button is installed at the second plate body with restriction.

5. The support apparatus with height adjustment as recited in claim 4, wherein a damping device is added to provide damping resistance for the second body during the descending process.

6. The support apparatus with height adjustment as recited in claim 5, wherein the damping device is set into the second body, and constructed by a damping slot and a damping block with mutual cooperation; therein, the damping slot is formed by caving in an inside surface of the second body, and an opening of the damping slot faces to a first surface defined at a part of the inner surface of the first body; the damping slot includes an oblique and caved inside cuneal slot; and the damping block is mounted on the bottom of the damping slot; the damping block is installed inside the damping slot with a vertically sliding way, and a cuneal part is formed and fitted on the top of the damping slot; forward contact force between the damping block and the first surface increases, as the cuneal part of the damping block is locked into the cuneal slot of the damping slot.

7. The support apparatus with height adjustment as recited in claim 6, wherein an elastic element is added to connect both the damping slot and the damping block of the damping device, and the damping block tends to go back to the first position.

8. The support apparatus with height adjustment as recited in claim 1, wherein a second surface defined at another part of the inner surface of the first body and a surface of the second body corresponding to the second surface have a sliding-track and a guiding rib respectively;

wherein the sliding-track is corresponded to the guiding rib and is concave and extended along the axial of the guiding part while the guiding rib is convex and extended along the axial of the guiding part.

9. The support apparatus with height adjustment as recited in claim 1, wherein the elastic structure which restrains the button is a beam installed in the first body, and the beam has a designed elastic deformation range which the button reaches the second state with an external force while the button reaches the first state without the external force.

10. The support apparatus with height adjustment as recited in claim 1, wherein a buck is pivoted at lower of the tenon and forms the said under flange at upper thereof; and the said button installed in the first body and is corresponding to the under flange.

11. The support apparatus with height adjustment as recited in claim 10, wherein a buck is pivoted at a lower arm of the tenon and forms the said under flange at upper arm thereof while a lower arm of the buck is pivoted at the first body.

12. The support apparatus with height adjustment as recited in claim 11, wherein the button is installed in the first body and is corresponding to the under flange.

13. The support apparatus with height adjustment as recited in claim 11, wherein the buck has a leaf spring corresponding to the button.

14. The support apparatus with height adjustment as recited in claim 13, wherein the button is installed in the first body and is corresponding to the tenon and the leaf spring of the under flange.

15. The support apparatus with height adjustment as recited in claim 10, wherein a frame is installed at the first body to form the space, and the frame is restricted at the first body but has a vertical freedom to allow vertical movement thereof; and the buffer is installed under the frame, and the buffer is contacted to a protrusion of the first body for being a buffer to absorb an impact caused by the second body.

16. The support apparatus with height adjustment as recited in claim 15, wherein the buffer is selected from rubber, spring or any buffer materials.

17. A support apparatus with height adjustment comprising:

a first body, which is a structure body constructed by a first plate body and a second plate body which defined an inner space as the guiding part, and a button slidingly mounted on the second plate body with restriction;

a second body, which is a plate body and is installed into the guiding part of said first body with a vertically up/down sliding way, includes a rectangular hole which extends vertically and has a plurality of slots ranked along the rectangular hole; and

a tenon, which is a plate body axially mounted on local part of the first plate body; having a top part formed on the top of the tenon and an under flange formed on one surface of bottom of the tenon so as to selectively be interfered with a slot of the second body;

a LCD screen, mounted on the top of the second body, therein, a button of the second plate body is designed to co-operate with the tenon; and a spring, which is mounted and respectively connected to the second plate body and the tenon at two ends, is used for providing elastic force to so as to maintain the tenon tending a first state, and to limit the tenon reaching a second state by operating the button; therefore, the tenon is a mechanism used for selecting vertically upward or downward motion of the second body, and the button is co-operated with the rectangular hole, so no mechanical interference is produced by the button and the first plate body.

18. The support apparatus with height adjustment as recited in claim 17, wherein a coupling stage is mounted on the top of the second body, and a shackle structure is formed on the top of the coupling stage.

19. The support apparatus with height adjustment as recited in claim 18, wherein a supporting structure is formed on the bottom of the first body, which is used to support and maintain balance of the whole support apparatus with height adjustment and the LCD screen.

20. The support apparatus with height adjustment as recited in claim 18, wherein a coupling stage is added on the top of the second body, and the LCD screen is axially connected to the coupling stage.

21. The support apparatus with height adjustment as recited in claim 20, wherein the method for axially connecting the tenon is along the direction of torque caused by elastic force of the spring, and opposite to the direction of torque caused by pressing force of the button.

22. The support apparatus with height adjustment as recited in claim 21, wherein the tenon is at the first state while the spring is at a balance position, the top part of the tenon is released from a first slot of the second body, and the under flange of the tenon is interfered with a second slot of the second body; and the tenon is at the second state while the button is pressed to oppose an elastic force of the spring, the under flange of the tenon is released from the second slot of the second body slot, and the top part of the tenon is interfered with a third slot.

23. The support apparatus with height adjustment as recited in claim 22, wherein a damping device is added to provide damping resistance for the second body during the descending process.

24. The support apparatus with height adjustment as recited in claim 23, wherein the damping device is set into the second body, and constructed by a damping slot and a damping block with mutual cooperation; therein, the damping slot is formed by caving in an inside surface of the second body, and an opening of the damping slot faces to the first plate body; the damping slot includes an oblique cuneal slot which is caved inside; and the damping block is mounted on the bottom of the damping slot; the damping block is installed inside the damping slot with a vertically sliding way, and a cuneal part is formed and fitted on the top of the damping slot; forward contact force between the damping block and the first plate body increases, as the cuneal part of the damping block is locked into the cuneal slot of the damping slot.

25. The support apparatus with height adjustment as recited in claim 24, wherein an elastic element is added to connect both the damping slot and the damping block of the damping device, and the damping block tends go back to the first position.