CN217117891U

CN217117891U - Three-section sliding rail capable of realizing synchronous motion

Info

Publication number: CN217117891U
Application number: CN202123125415.6U
Authority: CN
Inventors: 邓小林
Original assignee: Huizhou Wanli Hengtong Hardware Co ltd
Current assignee: Huizhou Wanli Hengtong Hardware Co ltd
Priority date: 2021-12-13
Filing date: 2021-12-13
Publication date: 2022-08-05
Anticipated expiration: 2031-12-13

Abstract

The utility model discloses a three-section sliding rail capable of realizing synchronous motion, which comprises an outer rail, a middle rail and an inner rail, wherein the outer rail is connected with the middle rail in a left-right sliding way, and the middle rail is connected with the inner rail in a left-right sliding way; the left end of well rail is equipped with and plays the arm, the expansion end of bullet arm is equipped with first spacing portion, the left end of interior rail is equipped with the spacing portion of second, first spacing portion with the spacing portion of second can carry out spacing cooperation, the right-hand member of well rail is equipped with the spacing portion of third, the right-hand member of interior rail is equipped with the spacing portion of fourth, the spacing portion of third with the spacing portion of fourth can carry out spacing cooperation, in order to restrict the interior rail for well rail carries out the side-to-side motion. The utility model has the advantages of reasonable design, it can be according to user's needs, selects interior rail and well rail to carry out relative motion, still carries out synchronous motion to provide more selections for the user, thereby convenience of customers' use.

Description

Three-section sliding rail capable of realizing synchronous motion

Technical Field

The utility model relates to a slide rail technical field especially relates to a can realize synchronous motion's three section slide rail.

Background

The three-section sliding rail generally comprises an outer rail, a middle rail, an inner rail, a ball nest and balls. Be provided with dog and shelves point on the outer rail, can prevent that the ball from deviating from and leading to well rail and outer rail separation. The middle rail is arranged on the outer rail, the inner rail is arranged on the middle rail, and the middle rail is provided with a stop block and a stop point, so that the separation of the middle rail and the inner rail caused by the separation of the ball can be prevented. The ball is embedded on the ball nest or the ball strip. And ball nests and balls are arranged between the inner side surface of the outer rail and the outer side surface of the middle rail and between the inner side surface of the middle rail and the outer side surface of the inner rail.

The existing three-section sliding rail has the following problems: when pulling the inner rail, not only the middle rail and the outer rail can carry out relative motion, but also the inner rail and the middle rail can carry out relative motion, thereby carrying out relative motion only by the middle rail and the outer rail, but not carrying out relative motion by the inner rail and the middle rail, how to keep the inner rail and the middle rail in synchronous motion is a technical problem which needs to be solved urgently.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a can realize synchronous motion's three section slide rail to when the realization carries out relative motion at well rail and outer rail, the inner rail can keep synchronous motion with well rail.

In order to achieve the above object, the present invention provides a three-section sliding rail capable of realizing synchronous motion, which comprises an outer rail, a middle rail and an inner rail, wherein the outer rail is connected with the middle rail in a left-right sliding manner, and the middle rail is connected with the inner rail in a left-right sliding manner; the left end of well rail is equipped with and plays the arm, the expansion end of bullet arm is equipped with first spacing portion, the left end of interior rail is equipped with the spacing portion of second, first spacing portion with the spacing portion of second can carry out spacing cooperation, the right-hand member of well rail is equipped with the spacing portion of third, the right-hand member of interior rail is equipped with the spacing portion of fourth, the spacing portion of third with the spacing portion of fourth can carry out spacing cooperation, in order to restrict the interior rail for well rail carries out the side-to-side motion.

Further, the top of outer rail is equipped with the first spout that extends along left right direction, the top of well rail is equipped with the second spout that extends along left right direction, the bottom of interior rail is equipped with the third spout that extends along left right direction, well rail is located in the first spout, interior rail is located in the second spout.

Furthermore, the front side wall and the rear side wall of the first sliding groove are respectively in sliding connection with the front side wall and the rear side wall of the middle rail through bead strips, and the front side wall and the rear side wall of the second sliding groove are respectively in sliding connection with the front side wall and the rear side wall of the inner rail through bead nests.

Furthermore, a clamping locking glue is arranged at the left end of the first sliding groove, the clamping locking glue is arranged at the left side of the middle rail, and the front side wall and the rear side wall of the left end of the middle rail are respectively provided with a first clamping block; the preceding, the rear side wall of the right-hand member of first spout are equipped with second screens piece respectively, the right-hand member of well rail can pass the interval between the second screens piece of front and back both sides right, the pearl strip is located first screens piece with between the second screens piece.

Furthermore, the left end of the first limiting part and the right end of the second limiting part can be in limiting fit so as to limit the inner rail to move rightwards relative to the middle rail; the fourth limiting part is positioned on the right of the third limiting part, and the right end of the third limiting part and the left end of the fourth limiting part can be in limiting fit to limit the inner rail to move leftwards relative to the middle rail.

Furthermore, the elastic arm is arranged at the left end of the second sliding groove, and the second limiting part is arranged at the left end of the third sliding groove; the third limiting part is arranged at the right end of the second sliding groove, and the fourth limiting part is arranged at the right end of the third sliding groove.

Furthermore, the number of the elastic arms comprises two, the two elastic arms are distributed in sequence along the front-back direction, the right ends of the elastic arms on the front side and the back side are respectively connected with the front end and the back end of the fixing part, and the fixing part is fixed in the middle of the bottom surface of the second chute; the left end of the elastic arm is set as a movable end, and the first limiting part is arranged on the outer side of the movable end.

Furthermore, a guide plate is arranged in the middle of the first sliding groove, a guide groove is formed in the top of the guide plate, and the guide plate is arranged below the middle rail; the left end of the second sliding groove is provided with a through hole which penetrates downwards to the first sliding groove, the bottom of the movable end of the elastic arm is provided with a guide block, the guide block penetrates downwards through the through hole to reach the inside of the first sliding groove, and the guide block and the guide groove can be matched in a guiding mode, so that the movable ends of the elastic arms are mutually closed.

Furthermore, the left end of the guide groove is provided with an opening, the space of the guide groove gradually shrinks from left to right to the middle, and the front side wall and the rear side wall of the guide groove are respectively provided with a first arc-shaped surface; the outside of guide block is equipped with the second arcwall face, first arcwall face second arcwall face all is from a left side to right side to middle extension gradually.

Furthermore, grooves are respectively arranged on the front side and the rear side of the top of the third limiting part, and the front side wall and the rear side wall of the right end of the inner rail are respectively in sliding fit with the grooves on the front side and the rear side; the top of the third limiting part is also provided with a convex strip which is arranged between the grooves at the front side and the rear side; the middle part of third spout is equipped with the spacing portion of fifth, the right-hand member of the spacing portion of fifth can with the left end of sand grip carries out spacing cooperation, in order to restrict the interior rail is followed the right-hand member of well rail breaks away from.

To sum up, the application the technical scheme of the utility model, following beneficial effect has: the utility model has the advantages of reasonable structural design, (1) carry out spacing cooperation through first spacing portion and second spacing portion, and third spacing portion carries out spacing cooperation with fourth spacing portion, comes to restrict the inner rail and carries out the side-to-side motion relative to the middle rail, thereby when pulling the inner rail, only middle rail and outer rail carry out relative motion, and inner rail and middle rail will keep synchronous motion; (2) the first limiting part is arranged at the movable end of the elastic arm, so that when the movable end of the elastic arm is driven to enable the first limiting part and the second limiting part to be staggered, relative movement between the inner rail and the middle rail can be realized; (3) according to the analysis above, the utility model discloses a three section slide rail can be according to user's needs, selects interior rail and well rail to carry out relative motion, still carries out synchronous motion to provide more selections for the user, thereby convenience of customers' use.

Drawings

Fig. 1 is a schematic top view of the present invention;

FIG. 2 is a schematic top view of the present invention with the inner rail removed;

fig. 3 is a schematic top view of the outer rail of the present invention;

fig. 4 is a schematic top view of the middle rail of the present invention;

fig. 5 is a schematic top view of the middle rail of the present invention with the spring arm removed;

fig. 6 is a schematic bottom view of the elastic arm of the present invention;

fig. 7 is a schematic top view of the inner rail of the present invention;

fig. 8 is a schematic bottom view of the inner rail of the present invention;

description of reference numerals: 1-an outer rail, 101-a first chute and 102-a second clamping block; 2-middle rail, 201-second sliding groove, 202-first clamping block, 203-through hole; 3-inner rail, 301-third chute; 4-elastic arm, 401-guide block, 402-second arc surface; 5-a first limiting part, 6-a second limiting part; 7-a third limiting part, 701-a groove and 702-a convex strip; 8-a fourth limiting part, 9-bead strips, 10-bead nests, 11-clamping locking glue and 12-a fixing part; 13-guide plate, 1301-guide groove, 1302-first arc face; 14-fifth limiting part.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, but the technical solution does not limit the scope of the present invention.

In the present invention, for the sake of clearer description, the following explanation is made: the observer is observing in the face of fig. 1, the left side of the observer is set as left, the right side of the observer is set as right, the front side of the observer is set as down, the rear side of the observer is set as up, the upper side of the observer is set as front, the lower side of the observer is set as back, it should be noted that the terms "front end", "rear end", "left side", "right side", "middle part", "upper part", "lower part" and the like in the text indicate the orientation or position relationship to be based on the orientation or position relationship set up by the drawings, only for the convenience of clearly describing the present invention, but not to indicate or suggest that the structure or part indicated must have a specific orientation, be constructed in a specific orientation, and therefore, cannot be understood as a limitation of the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used merely for purposes of clarity or simplicity of description and are not to be construed as indicating or implying relative importance or quantity.

Referring to fig. 1 to 8, the present embodiment provides a three-section sliding rail capable of realizing synchronous motion, including an outer rail 1, a middle rail 2, and an inner rail 3, where the outer rail 1 and the middle rail 2 are connected in a left-right sliding manner, and the middle rail 2 and the inner rail 3 are connected in a left-right sliding manner; the left end of well rail 2 is equipped with bullet arm 4, and the expansion end of bullet arm 4 is equipped with first spacing portion 5, and the left end of interior rail 3 is equipped with the spacing portion 6 of second, and spacing cooperation can be carried out with the spacing portion 6 of second in first spacing portion 5, and the right-hand member of well rail 2 is equipped with the spacing portion 7 of third, and the right-hand member of interior rail 3 is equipped with the spacing portion 8 of fourth, and spacing portion 7 of third and the spacing portion 8 of fourth can carry out spacing cooperation to the restriction interior rail 3 carries out the side-to-side motion for well rail 2. The function is as follows: (1) the first limiting part is in limiting fit with the second limiting part, and the third limiting part is in limiting fit with the fourth limiting part to limit the left-right movement of the inner rail relative to the middle rail, so that only the middle rail and the outer rail move relatively when the inner rail is pulled, and the inner rail and the middle rail keep synchronous movement; (2) the first limiting part is arranged at the movable end of the elastic arm, so that when the movable end of the elastic arm is driven to enable the first limiting part and the second limiting part to be staggered, relative movement between the inner rail and the middle rail can be realized; (3) according to the analysis above, the utility model discloses a three section slide rail can be according to user's needs, selects interior rail and well rail to carry out relative motion, still carries out synchronous motion to provide more selections for the user, thereby convenience of customers' use. Preferably, the first stopper portion, the second stopper portion, the third stopper portion, and the fourth stopper portion are block-shaped or plate-shaped.

Specifically, the top of the outer rail 1 is provided with a first sliding groove 101 extending along the left-right direction, the top of the middle rail 2 is provided with a second sliding groove 201 extending along the left-right direction, the bottom of the inner rail 3 is provided with a third sliding groove 301 extending along the left-right direction, the middle rail 2 is arranged in the first sliding groove 101, and the inner rail 3 is arranged in the second sliding groove 201. The function is as follows: through setting up first spout, second spout, third spout to make things convenient for the sliding fit between outer rail and the well rail, between well rail and the interior rail.

Specifically, the front and rear side walls of the first sliding groove 101 are respectively connected with the front and rear side walls of the middle rail 2 in a sliding manner through the bead strips 9, and the front and rear side walls of the second sliding groove 201 are respectively connected with the front and rear side walls of the inner rail 3 in a sliding manner through the bead nests 10. The function is as follows: through setting up pearl nest, pearl strip to make between outer rail and the well rail, sliding fit between interior rail and the well rail more smooth and easy.

Specifically, the left end of the first sliding chute 101 is provided with a clamping locking glue 11, the clamping locking glue 11 is arranged at the left side of the middle rail 2, and the front side wall and the rear side wall of the left end of the middle rail 2 are respectively provided with a first clamping block 202; the front side wall and the rear side wall of the right end of the first sliding groove 101 are respectively provided with a second clamping block 102, the right end of the middle rail 2 can penetrate through the interval between the second clamping blocks 102 on the front side and the rear side rightwards, and the bead 9 is arranged between the first clamping block 202 and the second clamping block 102. The function is as follows: the clamping lock glue is used for preventing the middle rail from excessively moving leftwards, so that the middle rail is prevented from being separated from the outer rail after excessively moving leftwards, and meanwhile, the clamping lock glue also has a locking function on the inner rail, namely, the clamping lock glue can enter the inner side of the left end of the inner rail from the left end opening of the inner rail; and after the middle rail moves to a certain degree to the right, the right end of the bead strip can be collided with the second clamping block, and the first clamping block can be collided with the left end of the bead strip, so that the middle rail is prevented from continuing to move to the right, and the middle rail is prevented from being separated from the outer rail after excessively moving to the right.

Specifically, the left end of the first limiting part 5 and the right end of the second limiting part 6 can be in limiting fit to limit the inner rail 3 to move rightwards relative to the middle rail 2; the fourth limiting part 8 is located on the right of the third limiting part 7, and the right end of the third limiting part 7 and the left end of the fourth limiting part 8 can be in limiting fit to limit the inner rail 3 to move leftwards relative to the middle rail 2. The function is as follows: the inner rail is prevented from moving rightwards relative to the middle rail through the matching of the first limiting part and the second limiting part, and the inner rail is prevented from moving leftwards relative to the middle rail through the matching of the third limiting part and the fourth limiting part, so that the inner rail and the middle rail keep synchronous movement through the structure.

Specifically, the elastic arm 4 is arranged at the left end of the second sliding chute 201, and the second limiting part 6 is arranged at the left end of the third sliding chute 301; the third limiting portion 7 is disposed at a right end of the second sliding groove 201, and the fourth limiting portion 8 is disposed at a right end of the third sliding groove 301. The function is as follows: through locating the second spout with bullet arm, the spacing portion of third to and locate the third spout with the spacing portion of second, the spacing portion of fourth, thereby make the distance between the spacing portion of first spacing portion and second and the distance between the spacing portion of third and the spacing portion of fourth closer, thereby make things convenient for the cooperation more.

Specifically, the number of the elastic arms 4 includes two, the two elastic arms 4 are sequentially distributed along the front-back direction, the right ends of the elastic arms 4 at the front side and the rear side are respectively connected with the front end and the rear end of the fixing portion 12, and the fixing portion 12 is fixed in the middle of the bottom surface of the second chute 201; the left end of the elastic arm 4 is a movable end, and the first limit part 5 is arranged outside the movable end. The function is as follows: through the arrangement of the two elastic arms, a U-shaped opening towards the left is formed between the two elastic arms, so that the two elastic arms form a slingshot effect, and the elastic force for resetting is sufficient. It should be noted that, although there are two elastic arms, there is only one second limiting portion, and the second limiting portion is in limiting fit with the first limiting portion of one of the two elastic arms, so that cost is saved while limiting is guaranteed.

Specifically, a guide plate 13 is arranged in the middle of the first sliding chute 101, a guide groove 1301 is arranged at the top of the guide plate 13, and the guide plate 13 is arranged below the middle rail 2; the left end of the second sliding groove 201 is provided with a through hole 203 which penetrates downwards to the first sliding groove 101, the bottom of the movable end of the elastic arm 4 is provided with a guide block 401, the guide block 401 penetrates downwards through the through hole 203 to reach the first sliding groove 101, and the guide block 401 and the guide groove 1301 can be matched in a guiding mode, so that the movable ends of the elastic arms 4 are close to each other. The function is as follows: the guide plate is arranged in the middle of the first sliding groove, so that when the guide block of the elastic arm is positioned at the left side of the guide plate, the movable ends of the front elastic arm and the rear elastic arm are opened, the first limiting part can be in limiting fit with the second limiting part, and the middle rail and the inner rail can keep synchronous motion due to the matching effect of the third limiting part and the fourth limiting part; and when the guide block of bullet arm enters into the guide way right, because the guide effect of guide way, the expansion end of two preceding and back bullet arms is drawn close to the centre respectively to make the spacing cooperation between first spacing portion and the spacing portion of second destroyed, thereby make the spacing portion of second can continue to move right, thereby make the inner rail can move right for well rail. That is, when the guide block is located at the left of the guide groove, the inner rail moves in synchronization with the middle rail, and when the guide block is located at the guide groove, the inner rail can move rightward with respect to the middle rail.

Specifically, the left end of the guide groove 1301 is provided with an opening, the space of the guide groove 1301 gradually shrinks from left to right to the middle, and the front and rear side walls of the guide groove 1301 are respectively provided with a first arc-shaped surface 1302; the outer side of the guide block 401 is provided with a second arc-shaped surface 402, and the first arc-shaped surface 1302 and the second arc-shaped surface 402 both extend gradually from left to right towards the middle. The function is as follows: through the arrangement of the guide grooves, when the guide blocks of the front elastic arm and the rear elastic arm enter the guide grooves rightwards, the space of the guide grooves is reduced, so that the front elastic arm and the rear elastic arm are respectively close to the middle, and the limit fit between the first limit part and the second limit part is damaged; and when the guide block goes out to the guide way outside to left, because the increase in space and the elastic force effect of bullet arm for two front and back bullet arms are separated each other, thereby make first spacing portion and the spacing portion of second can carry out spacing cooperation again. Preferably, an inclined surface or an arc surface extending from left to right to the middle is arranged on one side, away from the elastic arm, of the first limiting part, so that the second limiting part can return to the left of the first limiting part conveniently.

Specifically, both sides are equipped with recess 701 respectively around the top of the spacing portion 7 of third, and the preceding, the back lateral wall of the right-hand member of inner rail 3 carries out side to side sliding fit, effect with the recess 701 of both sides around respectively: the right-hand member that can make the inner rail can normally pass the second spout is set up like this, and the width of the spacing portion of third simultaneously can also be as big as the width of second spout. The top of the third limiting part 7 is also provided with a convex strip 702, and the convex strip 702 is arranged between the grooves 701 at the front side and the rear side; the middle part of third spout 301 is equipped with the spacing portion 14 of fifth, and the right-hand member of the spacing portion 14 of fifth can carry out spacing cooperation with the left end of sand grip 702 to the right-hand member of rail 2 breaks away from, the effect from in the restriction of 3 follow of interior rail: through the cooperation of sand grip and the spacing portion of fifth to prevent that the inner rail from breaking away from completely from the right-hand member mouth of second spout, because the middle part of third spout is located to the spacing portion of fifth, make and have certain activity space about between inner rail and the well rail moreover. Specifically, the fifth limiting portion may be in a block shape, a plate shape, a step shape, or the like, and may be selected as needed.

The foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations are also considered as the protection scope of the present invention.

Claims

1. The utility model provides a can realize synchronous motion's three section slide rail, includes outer rail (1), well rail (2), inner rail (3), its characterized in that: the outer rail (1) is connected with the middle rail (2) in a left-right sliding mode, and the middle rail (2) is connected with the inner rail (3) in a left-right sliding mode; the left end of well rail (2) is equipped with bullet arm (4), the expansion end of bullet arm (4) is equipped with first spacing portion (5), the left end of interior rail (3) is equipped with spacing portion of second (6), first spacing portion (5) with spacing portion of second (6) can carry out spacing cooperation, the right-hand member of well rail (2) is equipped with spacing portion of third (7), the right-hand member of interior rail (3) is equipped with spacing portion of fourth (8), spacing portion of third (7) with spacing portion of fourth (8) can carry out spacing cooperation, in order to restrict interior rail (3) for well rail (2) carry out the side-to-side motion.

2. The three-section sliding rail capable of realizing synchronous motion according to claim 1, wherein: the top of outer rail (1) is equipped with first spout (101) that extend along left right direction, the top of well rail (2) is equipped with second spout (201) that extend along left right direction, the bottom of interior rail (3) is equipped with third spout (301) that extend along left right direction, well rail (2) are located in first spout (101), interior rail (3) are located in second spout (201).

3. The three-section sliding rail capable of realizing synchronous motion according to claim 2, wherein: the front side wall and the rear side wall of the first sliding groove (101) are respectively in sliding connection with the front side wall and the rear side wall of the middle rail (2) through the bead strips (9), and the front side wall and the rear side wall of the second sliding groove (201) are respectively in sliding connection with the front side wall and the rear side wall of the inner rail (3) through the bead nests (10).

4. The three-section sliding rail capable of realizing synchronous motion according to claim 3, wherein: a clamping locking glue (11) is arranged at the left end of the first sliding groove (101), the clamping locking glue (11) is arranged at the left side of the middle rail (2), and the front side wall and the rear side wall of the left end of the middle rail (2) are respectively provided with a first clamping block (202); the front side wall and the rear side wall of the right end of the first sliding groove (101) are respectively provided with a second clamping block (102), the right end of the middle rail (2) can penetrate through the interval between the second clamping blocks (102) on the front side and the rear side rightwards, and the bead strips (9) are arranged between the first clamping block (202) and the second clamping blocks (102).

5. The three-section sliding rail capable of realizing synchronous movement according to any one of claims 2 to 4, wherein: the left end of the first limiting part (5) and the right end of the second limiting part (6) can be in limiting fit so as to limit the inner rail (3) to move rightwards relative to the middle rail (2); the spacing portion of fourth (8) is located the right-hand side of the spacing portion of third (7), the right-hand member of the spacing portion of third (7) with the left end of the spacing portion of fourth (8) can carry out spacing cooperation, in order to restrict the inner rail (3) for well rail (2) move left.

6. The three-section sliding rail capable of realizing synchronous motion according to claim 5, wherein: the elastic arm (4) is arranged at the left end of the second sliding groove (201), and the second limiting part (6) is arranged at the left end of the third sliding groove (301); the third limiting part (7) is arranged at the right end of the second sliding groove (201), and the fourth limiting part (8) is arranged at the right end of the third sliding groove (301).

7. The three-section sliding rail capable of realizing synchronous motion according to claim 6, wherein: the number of the elastic arms (4) comprises two, the two elastic arms (4) are sequentially distributed along the front-back direction, the right ends of the elastic arms (4) on the front side and the back side are respectively connected with the front end and the back end of a fixing part (12), and the fixing part (12) is fixed in the middle of the bottom surface of the second sliding chute (201); the left end of the elastic arm (4) is set as a movable end, and the first limiting part (5) is arranged on the outer side of the movable end.

8. The three-section sliding rail capable of realizing synchronous motion according to claim 7, wherein: a guide plate (13) is arranged in the middle of the first sliding groove (101), a guide groove (1301) is formed in the top of the guide plate (13), and the guide plate (13) is arranged below the middle rail (2); the left end of second spout (201) is equipped with and link up to down through-hole (203) of first spout (101), the bottom of the expansion end of bullet arm (4) is equipped with guide block (401), guide block (401) pass downwards through-hole (203) reachs in first spout (101), guide block (401) with guide way (1301) can lead the cooperation, so that draw close each other between the expansion end of bullet arm (4).

9. The three-section sliding rail capable of realizing synchronous motion according to claim 8, wherein: the left end of the guide groove (1301) is provided with an opening, the space of the guide groove (1301) gradually shrinks from left to right to the middle, and the front side wall and the rear side wall of the guide groove (1301) are respectively provided with a first arc-shaped surface (1302); the outer side of the guide block (401) is provided with a second arc-shaped surface (402), and the first arc-shaped surface (1302) and the second arc-shaped surface (402) both gradually extend from left to right towards the middle.

10. The three-section sliding rail capable of realizing synchronous movement according to any one of claims 6 to 9, wherein: grooves (701) are respectively formed in the front side and the rear side of the top of the third limiting part (7), and the front side wall and the rear side wall of the right end of the inner rail (3) are respectively in sliding fit with the grooves (701) in the front side and the rear side; a convex strip (702) is further arranged at the top of the third limiting part (7), and the convex strip (702) is arranged between the grooves (701) on the front side and the rear side; the middle part of third spout (301) is equipped with spacing portion of fifth (14), the right-hand member of spacing portion of fifth (14) can with the left end of sand grip (702) carries out spacing cooperation, in order to restrict interior rail (3) are followed the right-hand member of well rail (2) breaks away from.