TWM497722U - Linear guideway and passageway module thereof - Google Patents

Description

Linear slide and its channel module

This creation is related to a linear slide, and in particular to a miniature linear slide and its channel module.

In addition to the specification of miniature linear slides, micro-linear slides usually refer to linear slides with wire retainers, and most of the balls used in miniature linear slides do not maintain their relative positions with chains. Further, the conventional miniature linear slide defines a circulation passage through a common surrounding of the slider, the circulation seat, and the wire holder, and the circulation seat is directly pressed against the slider. However, each of the two ends of the circulation seat is provided with a turning portion, and each of the turning portions forms a gap with a slider portion adjacent thereto, so that when the ball rolls in the circulation passage, it is easy to be generated due to the influence of the above-mentioned deviation. Problems such as collision or unsatisfactory operation.

Therefore, the creator feels that the above-mentioned deficiency can be improved. He is devoted to research and cooperates with the application of theory, and finally proposes a creation that is reasonable in design and effective in improving the above-mentioned deficiency.

The present invention provides a linear slide rail and a channel module thereof, which can effectively improve the problem of the differential of the conventional micro linear slide rail.

The present invention provides a linear slide rail comprising: a track having a long strip shape and defining a long axis direction; a slider having a track groove formed in the recess, the track groove of the slider being movably sleeved on the a track, and the track grooves are respectively provided with an inner load surface parallel to the long axis direction on the two inner surfaces facing each other; two circulating seats are respectively disposed on opposite outer sides of the track groove of the slider, and the two cycles The seats are connected to each other The inner side load faces of the track groove, wherein each of the circulation seats comprises: an outer load surface located outside the corresponding inner load surface, and the outer load surface encloses an outer channel; and two steering portions Forming from opposite end edges of the outer load surface toward opposite end edges of the inner load surface; wherein each of the steering portions faces the end of the inner load surface from the corresponding outer load surface end edge Forming a turning surface and a connecting surface in sequence; in each of the turning portions, the end surface of the turning surface connected to the connecting surface forms a gap with the adjacent inner loading surface, and the connecting surface is located at the connecting surface The fault is connected to the corresponding inner load surface substantially without gap; the two wire retainers are respectively disposed corresponding to the two inner load faces, and each wire retainer is defined together with the corresponding inner load face thereof An inner side passage; two end covers are movably sleeved on the rail and respectively fixed to opposite ends of the slider, and each end cover is concavely formed on the surface adjacent to the slider to form two turns a steering slot, the steering portions of the two circulating seats are respectively inserted into the steering limiting slots of the two end covers, so that each steering portion and the corresponding steering limiting slot jointly define a steering channel; The inner passages and the corresponding two steering passages and the outer passages are collectively defined as a circulation passage; and a plurality of rolling members are respectively rollably accommodated in the two circulation passages.

Preferably, each of the opposite ends of each of the wire retainers is formed with a J-shaped barb, and each of the end caps is recessed on the surface away from the slider to form two barb slots, and the barbs are They are respectively received in the barb slots to maintain the position of the two wire retainers relative to the rolling elements.

The embodiment of the present invention further provides a channel module for a linear slide, comprising: a slider, the recess is formed with a track groove, and the track groove is provided with an inner load surface on each of the inner surfaces facing each other; Separately disposed on opposite sides of the track groove of the slider, and the two circulating seats are respectively connected to the two inner loading faces of the track groove, wherein each of the circulating seats comprises: an outer loading surface, corresponding to the corresponding An outer side of the inner load surface, and the outer load surface encloses an outer passage; and two steering portions respectively from opposite end edges of the outer load surface toward the inner load surface An opposite end edge is formed; wherein each of the steering portions is formed with a turning surface and a connecting surface from the end edge of the outer loading surface corresponding to the inner loading surface end edge; and in each of the turning portions, An end edge of the turning surface connected to the connecting surface forms a gap with the adjacent inner loading surface, and the connecting surface is located at the gap and is connected to the corresponding inner loading surface substantially without gap And two wire retainers respectively corresponding to the two inner load faces, and each wire retainer and its corresponding inner load face define an inner passage.

In summary, the linear slide rail and the passage module provided by the embodiment of the present invention are connected to the inner load surface through the joint surface substantially without gaps to complement the edge of the steering surface and the adjacent inner load surface. The step of the displacement, in turn, allows the rolling element to smoothly roll from the turning surface along the connecting surface to the inner load surface.

In order to further understand the features and technical contents of this creation, please refer to the following detailed description and drawings of this creation, but these descriptions and drawings are only used to illustrate this creation, not the right to this creation. The scope is subject to any restrictions.

100‧‧‧Linear slides (eg micro-linear slides)

1‧‧‧ Track

2‧‧‧ Slider

21‧‧‧ Track slot

22‧‧‧Inside load surface

221‧‧‧ first inner side

222‧‧‧Second inner side

23‧‧‧ Notch

3‧‧‧Recycling Block

3a, 3b‧‧‧ Loop sub-seat

31‧‧‧ Body Department

311‧‧‧Outside load surface

312‧‧‧ positioning slot

313‧‧‧Anti-stud

314‧‧‧Positioning column

315‧‧‧Defense slot

32‧‧‧Steering Department

321‧‧‧ turning surface

322‧‧‧ Connection surface

3221‧‧‧ first connection surface

3222‧‧‧Second connection surface

323‧‧‧Snap block

33‧‧‧ accommodating slots

4‧‧‧Steel retainer

41‧‧‧ Straight line

42‧‧‧ Barb

5‧‧‧End cover

51‧‧‧ steering limit slot

52‧‧‧ Barb slot

6‧‧‧Leather seat

61‧‧‧End dustproof sheet

62‧‧‧Bottom dustproof sheet

7‧‧‧Rolling parts (eg balls)

L‧‧‧ long axis direction

C‧‧‧Circulation channel

C1‧‧‧Outer channel

C2‧‧‧ inside channel

C3‧‧‧ steering channel

S‧‧‧断差

Figure 1 is a perspective view of the linear slide rail of the present invention.

2 is a perspective view of another perspective of FIG. 1.

3A is a schematic cross-sectional view taken along line X-X of FIG. 1.

Fig. 3B is an enlarged schematic view showing a portion 3B of Fig. 3A.

Figure 4 is a cross-sectional view taken along line Y-Y of Figure 1.

Fig. 5 is a perspective exploded view of Fig. 1 (omission of the track).

FIG. 6 is a schematic perspective view of a circulating seat of the linear slide.

Fig. 7 is a schematic view showing the combination of a recirculating seat and a slider of a linear slide.

Figure 8 is a schematic view of the slider of Figure 7.

Figure 9 is an exploded perspective view of the circulation seat of Figure 7.

Please refer to FIG. 1 to FIG. 9 , which is an embodiment of the present invention. It should be noted that the related quantity and appearance mentioned in the embodiment are only specifically described. The implementation of this creation is to facilitate understanding of its content, and not to limit the scope of the creation of this creation.

Please refer to Figure 1 and Figure 2, and consider Figures 3A and 4 as appropriate. This embodiment is a linear slide rail 100, especially a miniature linear slide rail 100, but is not limited thereto. The linear slide rail 100 includes a track 1, a slider 2, two circulating seats 3, two wire retainers 4, two end covers 5, a dustproof seat 6, and a plurality of rolling members 7. The track 1 is elongated and defines a long axis direction L. The two end seats 3 and the end caps 5 are mounted on the slider 2, and the two wire retainers 4 are mounted on the end caps 5, so that the above components jointly define two circulation passages C. In the present embodiment, the rolling elements 7 are spherical balls 7 and are respectively rollably accommodated in the two circulation passages C, and the slider 2 and the components disposed thereon are movable along the longitudinal direction L. The ground is mounted on the track 1. Hereinafter, the specific configurations of the respective elements of the linear slide rail 100 of the present embodiment will be described first, and then the mutual connection relationship between the components will be described later.

Referring to FIG. 5, the slider 2 is recessed to form a track groove 21 in a manner parallel to the longitudinal direction L, and the cross section of the slider 2 perpendicular to the longitudinal direction thereof is substantially symmetrical about a π shape (see FIG. 4). ). The track groove 21 of the slider 2 is movably sleeved on the rail 1, and the track groove 21 is provided with an inner load surface 22 parallel to the longitudinal direction L on both inner surfaces facing each other. Further, the slider 2 is provided with a notch 23 at opposite end edges of each inner load surface 22 (such as the left end and the right end corner of the slider 2 in FIG. 8).

As shown in FIG. 4, each of the inner loading surfaces 22 has a first arcuate inner side surface 221 and an arcuate second inner side surface 222 between the two first inner side surfaces 221, and each The radius of curvature of the first inner side surface 221 is substantially equal to the radius of any of the balls 7, and is greater than the radius of curvature of each of the second inner side surfaces 222. Accordingly, the balls 7 will abut against the two first inner side surfaces 221 of the inner load surface 22, and the balls 7 will not come into contact with the second inner side surface 222.

Referring to FIG. 5, the two circulating seats 3 are respectively disposed on opposite outer sides of the track groove 21 of the slider 2 (the left outer side and the right outer side of the track groove 21 in FIG. 5), and the two circulating seats 3 are respectively connected to each other. The inner side load faces 22 of the track grooves 21, that is to say each of the circulation seats 3, have an inner load surface 22. It should be noted that the two circulation seats 3 are substantially the same structure in this embodiment. For ease of understanding, the following will only be directed to the configuration and relative relationship of one of the circulation seats 3 and the corresponding inner load surface 22 thereof. Make a note.

Referring to FIG. 6 , the circulation seat 3 includes an elongated body portion 31 and two steering portions 32 respectively extending from opposite ends of the body portion 31 . The body portion 31 is formed with an outer passage C1 penetrating therethrough. That is, as shown in FIG. 4, the body portion 31 has an outer load surface 311 surrounding the outer passage C1, and the outer load surface 311 is substantially positioned. It corresponds to the outer side of the inner load surface 22 .

As shown in FIG. 7, the two steering portions 32 are formed to extend from opposite end edges of the outer loading surface 311 toward opposite end edges of the inner loading surface 22, respectively, and the two steering portions 32 are substantially located on the outer side. Between the virtual extension faces of both the load surface 311 and the inner load surface 22 . Each of the steering portions 32 extends from the end edge of the corresponding outer load surface 311 toward the end edge of the inner load surface 22 to form an arc-shaped turning surface 321 and a connecting surface 322.

In each of the turning portions 32, the cross section of the turning surface is substantially a semicircular shape of 180 degrees, and is connected to the end edge of the turning surface 321 of the connecting surface 322 (as shown in the right end edge of the turning surface 321 in FIG. 3B). A gap S is formed with the adjacent inner load surface 22 . It should be noted that the above-mentioned gap S corresponds to the position where the connecting surface 322 of the present embodiment is located. That is to say, in this embodiment, the connecting surface 322 is located at the gap S and is substantially free of gaps with the inner loading surface 22 . In order to complement the above-described gap S, the ball 7 can be smoothly rolled by the turning surface 321 along the connecting surface 322 to the inner load surface 22.

Each of the connecting surfaces 322 has two arc-shaped first connecting surfaces 3221 and an arc-shaped second connecting surface 3222 between the two connecting surfaces 3221, and The radius of curvature of each of the first connecting faces 3221 is greater than the radius of curvature of each of the second connecting faces 3222. The two first connecting surfaces 3221 of each of the connecting surfaces 322 are respectively connected to the two first inner side surfaces 221 of the corresponding inner loading surface 22, and the second connecting surface 3222 of each connecting surface 322 is connected to the second connecting surface 3222 of the connecting surface 322. Corresponding inner side load surface 22 of second inner side 222. Accordingly, the balls 7 will abut against the two first connecting faces 3221 of the connecting face 322, and the balls 7 will not come into contact with the second connecting faces 3222.

Further, referring to FIG. 6 to FIG. 9, each of the circulation seats 3 has two circulating sub-seats 3a, 3b which are mutually coupled in this embodiment, and the mutual joint portions of the two circulating sub-seats 3a, 3b Roughly located at the center of the body portion 31, that is, each of the circulation seats 3 is divided into the above-mentioned two circulation sub-seats 3a, 3b by the substantially center of the body portion 31, so that each of the circulation sub-seats 3a, 3b A steering portion 32 can be provided.

As shown in FIG. 9, in each of the circulation seats 3, a portion where the two circulating sub-seats 3a, 3b are in contact with each other (that is, an end surface corresponding to the two circulating sub-seats 3a, 3b are connected to each other), one of which cycles The sub-seat 3a is formed with a positioning groove 312 and a foolproof column 313, and the other circulating sub-seat 3b is formed with a positioning post 314 and a anti-staying groove 315. The positioning groove 312 and the positioning post 314 each surround the outer edge of the outer channel C1, and the positioning groove 312 and the positioning post 314 are configured to be able to fit each other. The anti-stasis post 313 and the anti-stagnation slot 315 are respectively located at one side of the positioning slot 312 and the positioning post 314, and the positioning slot 312 and the positioning post 314 are configured to be interpenetrated with each other.

Furthermore, each of the circulation sub-seats 3a, 3b is provided with a fastening block 323 which is capable of being in close contact with the recess of the slider 2 at a connecting surface 322 of the steering portion 32. Further, the main body portion 31 of each of the recirculation seats 3 and the two steering portions 32 have a substantially U-shaped configuration and are integrally formed with a receiving groove 33 (FIG. 6), and the fastening block 323 protrudes from the receiving portion. Within the slot 33, and at least a portion of the connecting surface 322 is the outer surface of the snap block 323.

Accordingly, as shown in FIGS. 7 to 9, the two circulating sub-seats 3a, 3b of each of the recirculating seats 3 are respectively opposite from the opposite ends of the corresponding inner loading surface 22 and parallel to the long axis direction. The slider 2 is mounted in the accommodating groove 33 at a portion where the slider 2 is provided with the inner load surface 22 . The positioning post 314 is inserted into the positioning slot 312, and the anti-staying post 313 is inserted into the anti-dwelling slot 315, and the fastening block 323 is respectively inserted into the notch 23 so that each connecting surface 322 is The corresponding inner load faces 22 are substantially in contact with each other without a gap.

With the above design, each of the recirculating seats 3 of the present embodiment is fastened to the slider 2 in the parallel longitudinal direction L through the two circulating sub-seats 3a, 3b, thereby replacing the conventional recirculating seat directly with the slider. In addition, the assembly error that the conventional circulation seat directly presses on the slider is avoided, and the assembly precision and speed between the circulation seat 3 and the slider 2 are effectively improved.

3A to 5, the wire retainer 4 includes a straight portion 41 and two J-shaped barbs 42 extending perpendicularly from opposite ends of the straight portion 41, that is, each wire is retained. A J-shaped barb 42 is formed at each of opposite end portions of the device 4. Further, the two wire retainers 4 are respectively disposed corresponding to the two inner load faces 22, the straight portions 41 are substantially parallel to the long axis direction L, and when the straight portion 41 of each wire retainer 4 is projected onto the front portion thereof Corresponding to the inner load surface 22, the orthographic projection area is substantially located on the second inner side surface 222, and the plane of each of the barbs 42 is substantially perpendicular to the longitudinal direction L.

Thereby, the straight portion 41 of each wire retainer 4 and its corresponding inner load surface 22 define an inner passage C2. The two first inner side surfaces 221 of each of the wire retainers 4 and the corresponding inner load surface 22 thereof are abutted against the balls 7 in a three-point positioning manner, so that the balls 7 can be stably inside the inner passage C2. scroll.

It should be noted that the combination of the slider 2, the circulation seat 3, and the wire holder 4 of the present embodiment may also be referred to as a channel module (not shown) of the linear slide 100. Similarly, the channel module of the linear slide 100 referred to herein refers to a channel module of the miniature linear slide 100, but is not limited thereto.

The two end covers 5 are movably sleeved on the rail 1, and the two end covers 5 are respectively fixed at opposite ends of the slider 2 (such as the left end and the right end of the slider 2 in FIG. 3A). Wherein, each end cover 5 is recessed and formed on the surface of the adjacent slider 2 (such as the right surface of the left end cover 5 in FIG. 3A) with two arc-shaped steering limiting slots 51, and each The end cover 5 is recessed on the surface of the end cover 5 away from the surface of the slider 2 (such as the left surface of the left end cover 5 in FIG. 3A), and two J-shaped barb slots 52 are formed, and the shape of the barb groove 52 is The barbs 42 of the wire holder 4 correspond.

In more detail, when the two end covers 5 are respectively fixed to opposite ends of the slider 2, the steering portions 32 of the two circulating seats 3 are respectively inserted into the steering limit slots 51 of the two end covers 5, In order to make each steering portion 32 together with its corresponding steering limit groove 51, a steering passage C3 is defined. Each inner channel C2 and its corresponding two steering channels C3 and the outer channel C1 are collectively defined as the above-mentioned circulation channel C. Furthermore, the barbs 42 are respectively received in the barb slots 52, so that the J-barbs 42 and the J-barb slots 52 are fitted to each other, so that the barbs 42 are not easily detached from the end caps 5, The position of the two wire retainers 4 relative to the rolling members 7 can be more stably maintained.

The dustproof seat 6 has an integrally formed structure and includes two substantially U-shaped end dustproof sheets 61 and two elongated bottom dustproof sheets 62 connected between the two end dustproof sheets 61. The two end dust guards 61 are respectively fastened to the surface of the end cover 5 away from the slider 2 (corresponding to the surface of the end cover 5 formed with the barb groove 52), and the inner edge of the end dustproof piece 61 abuts. On the surface of the rail 1 , the barb grooves 52 are respectively shielded by the two end dust guards 61 so that the barbs 42 are interposed between the end cover 5 and the end dust guard 61 . The longitudinal direction of the bottom dust guard 62 is substantially parallel to the longitudinal direction L, and the edges of the two bottom dust guards 62 facing each other abut against the opposite side surfaces of the rail 1, respectively.

[Possible effects of this creative embodiment]

In summary, the linear slide rail and the passage module provided by the embodiment of the present invention are connected to the inner load surface through the joint surface substantially without gaps to complement the edge of the steering surface and the adjacent inner load surface. The gap, in turn, allows the ball to smoothly roll from the turning surface along the connecting surface to the inner load surface.

Furthermore, in the embodiment, the two-circle sub-seat is fastened to the slider along the parallel long-axis direction, so as to replace the conventional recirculating seat and directly press the slider, thereby avoiding the assembly error that may occur, and effectively Improve the assembly accuracy and speed between the cycle seat and the slider.

In addition, in the embodiment, the J-bar barb of the wire retainer and the J-barb groove of the end cap are fitted, so that the barb of the wire retainer is not easily detached from the end cap, and the wire retaining can be more stably maintained. The position of the device relative to the scroll members.

The above is only a preferred embodiment of the present invention, and it is not intended to limit the scope of the patents of the present invention. Any changes and modifications made to the scope of the patent application of the present invention should be covered by the present invention.

22‧‧‧Inside load surface

311‧‧‧Outside load surface

321‧‧‧ turning surface

322‧‧‧ Connection surface

7‧‧‧Rolling parts (eg balls)

C1‧‧‧Outer channel

C2‧‧‧ inside channel

C3‧‧‧ steering channel

S‧‧‧断差

Claims (10)

A linear slide rail comprising: a track having a long strip shape and defining a long axis direction; a slider having a track groove formed in the recess, the track groove of the slider being movably sleeved on the track, and the track The two inner surfaces facing each other are respectively provided with an inner load surface parallel to the long axis direction; the two circulating seats are respectively disposed on opposite outer sides of the track groove of the slider, and the two circulating seats are respectively connected to The inner side load faces of the track groove, wherein each of the circulation seats comprises: an outer load surface located outside the corresponding inner load surface, and the outer load surface encloses an outer channel; and two steering portions Forming from opposite end edges of the outer load surface toward opposite end edges of the inner load surface; wherein each of the steering portions faces the end of the inner load surface from the corresponding outer load surface end edge Forming a turning surface and a connecting surface in sequence; in each of the turning portions, the end surface of the turning surface connected to the connecting surface forms a gap with the adjacent inner loading surface, and the connecting surface position The gap is connected to the corresponding inner load surface substantially without gaps; the two wire retainers are respectively disposed corresponding to the two inner load faces, and each wire retainer is defined together with the corresponding inner load face thereof An inner side passage is disposed; the two end covers are movably sleeved on the rail and respectively fixed to opposite ends of the slider, and each end cover is recessed on the surface adjacent to the slider to form two steering limit slots The steering portions of the two circulating seats are respectively inserted into the steering limiting slots of the two end covers, so that each steering portion and the corresponding steering limiting slot cooperate to define a steering channel; wherein each inner channel And corresponding to the two steering channels, the outer channel is defined as a circulation channel; and a plurality of rolling members are respectively rollably accommodated in the two circulation channels. The linear slide rail according to claim 1, wherein each of the circulation seats has two circulating sub-seats that are mutually connected, and each of the circulating sub-seats is provided with one of the turning portions; The slider is attached to the opposite ends of the inner load surface corresponding thereto and parallel to the long axis direction. The linear slide rail according to claim 2, wherein the slider is provided with a notch at opposite end edges of each inner load surface, and each of the circulation sub-seats corresponds to the connection surface of the steering portion. a fastening block is disposed, and the fastening blocks are respectively inserted into the notches, so that each of the connecting faces and the corresponding inner load surface thereof are mutually engaged through the fastening blocks and the notches. They meet in a substantially gap-free manner. The linear slide rail according to claim 3, wherein in each of the circulation seats, the two loop sub-seats are in contact with each other, one of which forms a positioning groove and a anti-staying column, and the other of the two forms a positioning. The column and the anti-staying groove, the positioning groove and the positioning column respectively surround the outer edge of the outer channel, and the anti-staying column and the anti-staying groove are respectively located at one side of the positioning groove and the positioning post; When the loop sub-seats are connected to each other, the positioning post is inserted into the positioning slot, and the anti-staying post is inserted into the anti-staying slot. The linear slide rail according to claim 1, wherein the rolling elements are spherical balls, and each of the inner loading surfaces has two arc-shaped first inner sides and between the two first inner sides. An arc-shaped second inner side surface, and each of the first inner side surfaces has a radius of curvature substantially equal to a radius of any of the balls and greater than a radius of curvature of each of the second inner side surfaces; each of the connecting surfaces has two arcs a first connecting surface and an arc-shaped second connecting surface between the two connecting surfaces, and a radius of curvature of each of the first connecting surfaces is greater than a radius of curvature of each of the second connecting surfaces; The two first connecting surfaces are respectively connected to the two first inner sides of the corresponding inner loading surface, and the second connecting surface of each connecting surface is connected to the second inner side of the corresponding inner loading surface . The linear slide of claim 5, wherein each of the turning surfaces has a semi-circular shape of substantially 180 degrees; and each of the steel retainers is projected onto the corresponding inner loading surface thereof, and the orthographic projection area thereof Is roughly located on the second inner side; each steel The two first inner sides of the wire holder and the corresponding inner load surface abut the balls in a three-point positioning manner so that the balls can stably roll within the inner passage. The linear slide of any one of claims 1 to 6, wherein each of the opposite ends of each of the wire retainers is formed with a J-shaped barb, each end cap being remote from the slider The surface is recessed to form two barb slots, and the barbs are respectively received in the barb slots to maintain the position of the two wire retainers relative to the rolling members. The linear slide rail of claim 7, further comprising a dustproof seat fastened to the surface of the end cover away from the slider, and the barb slots are respectively shielded by the dustproof seat. A channel module for a linear slide comprises: a slider, the recess is formed with a track groove, and the track groove is provided with an inner load surface on each of the inner surfaces facing each other; two circulating seats are respectively mounted on the slide The two orbital grooves of the block are opposite to each other, and the two circulating seats are respectively connected to the two inner loading faces of the track groove, wherein each of the circulating seats comprises: an outer loading surface, which is located on the inner loading surface corresponding thereto An outer side, and the outer load surface encloses an outer passage; and two steering portions respectively extend from opposite end edges of the outer load surface toward opposite end edges of the inner load surface; wherein each of the steering portions The corresponding outer loading surface end edge is sequentially formed with a turning surface and a connecting surface toward the inner loading surface end edge; in each steering portion, the turning surface end edge connected to the connecting surface is opposite to the phase Adjacent to the inner load surface, a gap is formed, and the connection surface is located at the fault and is substantially free of gaps with the corresponding inner load surface; and Two wire retainers are respectively disposed corresponding to the two inner load faces, and each wire retainer and the corresponding inner load face thereof define an inner passage. The channel module of the linear slide according to claim 9, wherein each of the circulation seats has two loop sub-seats that are mutually connected, and each of the loop sub-seats is provided with one of the steering portions; Each of the opposite end edges of the inner loading surface is provided with a notch, and each of the circulating sub-seats is provided with a fastening block corresponding to the connecting surface of the turning portion, and the two circulating sub-seats of each circulating seat are respectively The opposite ends of the corresponding inner load surface are mounted on the slider, and the fastening blocks are respectively inserted into the notches, so that each connecting surface and the corresponding inner load surface thereof are through the fastening The block and the notches are fitted to each other to be in contact with each other substantially without a gap.