阅读说明：本技术 一种易拉鞋带的鞋扣 (Shoe buckle of easy-to-pull shoelace ) 是由 赖宜华 于 2018-09-17 设计创作，主要内容包括：一种易拉鞋带的鞋扣,包含有：一底座、一防滑齿轮、一防松制动机构、一制动座控制机构。制动座控制机构包括底座上的弹性片,弹性片固设有阻挡齿牙。制动座的挡墙固设有立式手柄,该立式手柄为中空的套管,该管体内部套设有只能上下活动的活动按体。制动座靠近卡柱的的基板底部固设有一被阻齿牙,该被阻齿牙在制动座通过推动立式手柄离开卡柱后,被底座的弹性片上的阻挡齿牙卡住,此时可以轻松拉松或拉紧鞋带。通过按压立式手柄上的活动按体帽盖,弹性片及其阻挡齿牙会低于底座表面,从而释放被阻齿牙,制动座的挡墙也自动靠紧卡柱夹紧鞋带。(A shoe buckle of an easy-to-pull shoelace, comprising: a base, an antiskid gear, an anti-loosening braking mechanism, a braking seat control mechanism. The brake seat control mechanism comprises an elastic sheet on the base, and the elastic sheet is fixedly provided with a blocking tooth. The retaining wall of the brake seat is fixedly provided with a vertical handle which is a hollow sleeve, and a movable pressing body which can only move up and down is sleeved in the tube body. The bottom of the base plate of the brake seat close to the clamping column is fixedly provided with a blocked tooth, and the blocked tooth is blocked by the blocking tooth on the elastic sheet of the base after the brake seat leaves the clamping column by pushing the vertical handle, so that the shoelace can be easily loosened or tightened. By pressing the movable pressing body cap on the vertical handle, the elastic sheet and the blocking teeth thereof can be lower than the surface of the base, thereby releasing the blocked teeth, and the retaining wall of the brake seat also automatically leans against the clamping column to clamp the shoelace.)

1. The utility model provides a shoe buckle of easy-to-draw shoelace which characterized in that: comprises the following steps:

the base is used for being fixed on the upper of a shoe, and the middle part of the base is provided with a fixing shaft which extends vertically upwards;

the anti-slip gear is rotationally fixed on the fixed shaft, and the top surface of the anti-slip gear is covered with an expanded anti-slip cover plate;

the anti-loosening braking mechanism comprises a braking seat, an elastic top clamping piece and a clamping column fixed on the base; the brake seat comprises a base plate which is rotatably fixed on the fixed shaft and clamped between the anti-skid gear and the base, and a retaining wall which is fixed on the base plate on one side outside the anti-skid gear, the clamping columns are arranged on the base on one side of the retaining wall and can be abutted against the retaining wall, and the shoelace penetrates out from between the retaining wall and the clamping columns;

the elastic top clamping piece comprises a torsional spring fixed on the brake seat and an upright post fixed on the base, a first spring arm of the torsional spring is fixedly supported on the inner side of the retaining wall, a second spring arm is matched between the anti-skid gear and the opposite surface of the retaining wall, the second spring arm is V-shaped, the tail end of the second spring arm is provided with a retaining hook matched with the anti-skid gear, the upright post penetrates through a base plate between the retaining wall and the anti-skid gear to extend upwards and is clamped on the second spring arm, and the base plate is provided with a through groove matched with the upright post for small-angle rotation of the brake seat;

the brake seat control mechanism comprises an elastic sheet with elastic capacity, which is fixedly arranged on a base, and a blocking tooth is fixedly arranged in the middle of the elastic sheet; the edge of the brake seat, which is close to the bottom of the substrate of the clamping column, is fixedly provided with a blocked tooth; after the brake block leaves the rotation of kelly low-angle, the base plate by block tooth can be blocked by the tooth that blocks on the elastic sheet, at this moment, because of the stand on the brake block low-angle rotation back base can cooperate at the stopping hook one end tip of brake block torsional spring second spring arm, the stopping hook breaks away from anti-skidding gear promptly, anti-skidding gear can not receive the restriction of stopping hook when the pine or tight shoelace, can easily draw the pine this moment or take-up shoelace.

2. The shoe buckle of easy-to-draw shoelace as claimed in claim 1, wherein: one outward end of the blocking tooth of the base elastic sheet is fixedly provided with a convex body with a step slope facing the direction of the clamping column; the outer side surface of the retaining wall at the position of the brake seat close to the clamping column is fixedly provided with a vertical handle which is a hollow sleeve, the sleeve is internally sleeved with a movable pressing body which can only move up and down, the lower end of the movable pressing body is in an inverted cone shape, and the upper end of the movable pressing body is fixedly provided with an enlarged movable pressing body cap; the part of the upper end of the sleeve type vertical handle close to the clamping column extends upwards to form a blocking piece for protecting the cap of the movable pressing body, and the movable pressing body can normally move in the sleeve of the vertical handle when the vertical handle is pushed; the back is blocked by the tooth that blocks on the elastic sheet of base by the tooth that blocks of brake seat base plate, press the cap of the body through the activity of pressing in the vertical handle sleeve pipe, the activity can extrude the step domatic of the convex body on the elastic sheet of base according to the slope of body back taper lower extreme, make the brake seat compelled to remove to the kelly direction, the elastic sheet and block tooth can be less than the base surface because of the activity according to the effort of pressing of the body, thereby the release is blocked the tooth, because of the elasticity of torsional spring this moment, the stand can the automatic cooperation at second spring arm kink, the stopping hook blocks anti-skidding gear and prevents anti-skidding gear gyration, the barricade of brake seat also simultaneously automatic hugging closely the kelly and pressing from both sides.

3. The shoe buckle of easy-to-pull shoelace as claimed in any one of claims 1 to 2, wherein: a limiting hole is formed in the base; the bottom of the corresponding base plate is fixedly provided with a limit hook which can be hooked on the edge of the bottom of the limit hole of the base along with the small-angle rotation of the brake seat.

4. A shoe buckle of easy-to-pull shoelace as claimed in any one of claims 1 to 3, wherein: a fixed shaft is fixedly arranged on the base plate outside the torsion spring mounting shaft on the brake seat, and a rotatable pulley is sleeved on the fixed shaft.

5. The shoe buckle of easy-to-pull shoelace as claimed in any one of claims 1 to 4, wherein: the edge of the base outside the retaining wall of the brake seat is fixedly provided with an outer wall, the outer wall enables the shoelace to move at the top end of the outer wall and not to contact with a gap between the base plate and the base, and the outer wall protects the elastic piece of the base.

6. The shoe buckle of easy-to-pull shoelace as claimed in any one of claims 1 to 5, wherein: one side of the vertical handle close to the clamping column is fixedly provided with a tooth, the clamping column corresponding to the tooth is also fixedly provided with a tooth, and the two teeth are in a staggered state when being close to each other, so that the shoelace can be better gripped.

7. The shoe buckle of easy-to-pull shoelace as claimed in any one of claims 1 to 6, wherein: and the tail end of the first spring arm of the brake seat torsion spring is provided with a fixed hook which is fixedly supported in the fixing groove at the inner side of the retaining wall.

8. The shoe buckle of easy-to-pull shoelace as claimed in any one of claims 1 to 7, wherein: one end of the outer side of the base elastic sheet vertically extends to form a pressing column, and the function of the pressing column is the same as that of the movable pressing body.

9. The shoe buckle of easy-to-pull shoelace as claimed in any one of claims 1 to 8, wherein: the anti-falling cover plate extends from the top position close to the clamping column of the base to form a barrier sheet vertical to the direction of the base, and a groove matched with the barrier sheet of the anti-falling cover plate is formed in the inner side of the clamping column.

Technical Field

The invention relates to parts of shoes, in particular to a device for adjusting the tightness of shoes.

Background

The inventor applies for a rotary shoelace anti-loosening buckle with the patent number ZL201210213529.2 on the 27 th month 06 in 2012, and is characterized in that; comprises the following steps: the base is used for being fixed on the upper of a shoe, and the middle part of the base is provided with a fixing shaft which extends vertically upwards;

the anti-slip gear is rotationally fixed on the fixed shaft, and the top surface of the anti-slip gear is covered with an expanded anti-slip cover plate;

the anti-loosening braking mechanism comprises a braking seat, an elastic top clamping piece and a clamping column fixed on the base; the brake seat comprises a base plate which is rotationally fixed on the fixed shaft and clamped between the anti-slip gear and the base, and a retaining wall which is fixed on the base plate on one side outside the anti-slip gear, a handle is fixed on the outer side surface of the retaining wall, the clamping column is arranged on the base on one side of the retaining wall and can be abutted against the retaining wall, and the shoelace penetrates out from the position between the retaining wall and the clamping column.

Elastic top fastener is including fixing the torsional spring on the brake block and fixing the stand on the base, and the first spring arm of this torsional spring is fixed to be held on the barricade, and the cooperation of second spring arm is between anti-skidding gear and barricade opposite face, and second spring arm is V font and the tail end is equipped with the stopping hook with anti-skidding gear matched with, the stand activity is passed the base plate between barricade and the anti-skidding gear and is upwards extended elastic top card on second spring arm, set up on the base plate and cooperate and supply base plate small-angle pivoted through groove with the stand, the stand cooperation stopping hook blocks anti-skidding gear and prevents anti-skidding gear gyration and impel barricade and jack catch near when second spring arm kink, stopping hook breaks away from anti-skidding gear and impels barricade and jack catch separation when the stopping hook one end tip of second spring arm is cooperated to the stand cooperation of brake block small-angle rotation.

The defects of the invention are that:

one, during taut shoelace, the V font second spring arm because of the torsional spring of above-mentioned elasticity top fastener is in the spring state of opening, and the stand cooperation is at second spring arm kink, and the stopping hook outside can rub and harm the anti-skidding gear in the clockwise rotation, and the operator can feel simultaneously and feel the power of feeling.

Secondly, when the shoelace is pulled loose, an operator needs to push the handle on the retaining wall of the brake seat by hand and pull the shoelace loose by the other hand, which is not convenient.

Thirdly, under the tension of the shoelace, a gap is generated between the base plate of the braking seat and the base, and the shoelace is easily clamped between the base plate and the base, so that the operation is blocked.

Fourthly, the brake seat is unstable and is easy to be out of position.

Disclosure of Invention

The invention aims to solve the problems that the rotary shoelace is operated to prevent loosening and tightening the shoelace, the shoelace is inconvenient to tighten, and the anti-skid gear is damaged by the backstop hook; the shoelace is clamped between the base plate and the base, and the braking seat is unstable and easy to be out of position. A more convenient device is provided.

The purpose of the invention is realized by the following technical scheme:

the utility model provides a shoe buckle of easy-to-draw shoelace which characterized in that: comprises the following steps:

the base is used for being fixed on the upper of a shoe, and the middle part of the base is provided with a fixing shaft which extends vertically upwards;

and the anti-slip gear is rotationally fixed on the fixed shaft, and the top surface of the anti-slip gear is covered with an expanded anti-slip cover plate. The anti-drop cover plate is provided with a blocking sheet which is vertical to the base in an extending mode at the position, close to the top of the base clamping column, of the anti-drop cover plate. The edge of anticreep apron sets firmly the isolated column that extends to the base direction.

The anti-loosening braking mechanism comprises a braking seat, an elastic top clamping piece and a clamping column fixed on the base; the brake seat comprises a base plate which is rotationally fixed on the fixed shaft and clamped between the anti-slip gear and the base, and a retaining wall which is fixed on the base plate on one side outside the anti-slip gear, the clamping column is arranged on the base on one side of the retaining wall and can be abutted against the retaining wall, and the shoelace penetrates out from the position between the retaining wall and the clamping column. The inner side of the clamping column is provided with a groove which is matched with the separation sheet of the anti-falling cover plate to prevent the shoelace from escaping.

Elasticity top card spare is including fixing the torsional spring on the brake seat and fixing the stand on the base, and the tail end of the first spring arm of this torsional spring is equipped with the fixed hook and fixes the top and hold in the inboard fixed slot of barricade, the cooperation of second spring arm is between anti-skidding gear and barricade opposite face, and second spring arm is the V font and the tail end is equipped with the stopping hook with anti-skidding gear matched with, the stand passes the base plate between barricade and the anti-skidding gear upwards extends the top card on the second spring arm, set up on the base plate and cooperate and supply brake seat small-angle pivoted to link up the groove with the stand.

The brake seat control mechanism comprises an elastic sheet with elastic capacity arranged on a base, wherein the middle part of the elastic sheet is fixedly provided with a long strip-shaped blocking tooth with a triangular cross section, and the tooth surface facing the upright post forms an included angle with the surface of the elastic sheet. The outward end of the elastic sheet blocking tooth is fixedly provided with a convex body with a step slope surface facing the direction of the clamping column. The edge of the bottom of the substrate of the brake seat close to the clamping column is fixedly provided with a blocked tooth. After the brake block leaves the rotation of kelly low-angle, the base plate by block tooth can be blocked by the tooth that blocks on the elastic sheet, at this moment, because of the stand on the brake block low-angle rotation back base can cooperate at the stopping hook one end tip of brake block torsional spring second spring arm, the stopping hook breaks away from anti-skidding gear promptly, anti-skidding gear can not receive the restriction of stopping hook when the pine or tight shoelace, does not need the cooperation of both hands to stimulate the shoelace with light this moment.

The outer side surface of the retaining wall at the position of the brake seat close to the clamping column is fixedly provided with a vertical handle which is a hollow sleeve, a movable pressing body which can only move up and down is sleeved in the sleeve, the lower end of the movable pressing body is in an inverted cone shape, the upper end of the movable pressing body is fixedly provided with an enlarged movable pressing body cap, and the contact surface of fingers pressing the movable pressing body is increased when the brake seat is used; the part of the upper end of the sleeve type vertical handle close to the clamping column extends upwards to form a blocking piece for protecting the movable pressing body cap, so that fingers are prevented from contacting the movable pressing body cap when the vertical handle is pushed, and the movable pressing body can normally move in the sleeve of the vertical handle; the back is blocked by the tooth that blocks on the elastic sheet of base to the tooth that is blocked of brake seat base plate, press the cap of the body through pressing the activity in the vertical handle sleeve pipe, the activity can extrude the step domatic of the convex body on the base elastic sheet according to the back taper lower extreme slope of the body, make the brake seat compelled to remove to the kelly direction, the elastic sheet and block tooth can be less than the base surface because of the activity presses the effort of pressing of the body, thereby the release is blocked the tooth, because of the elasticity of the torsional spring on the brake seat this moment, the stand can automatic cooperation at second spring arm kink, the stopping hook blocks anti-skidding gear and prevents anti-skidding gear gyration, the barricade of brake seat also simultaneously automatic hugging closely the kelly and presss from both sides tight. The movable pressing body leaves the elastic sheet along with the vertical handle and is close to the clamping column, and the elastic sheet and the base are provided with slopes for the inverted conical lower end of the movable pressing body to flexibly pass through.

One end of the outer side of the base elastic sheet is vertically extended with a pressing column, and the function of the pressing column is the same as that of the movable pressing body.

One side of the vertical handle close to the clamping column is fixedly provided with a tooth, the clamping column corresponding to the tooth is also fixedly provided with a tooth, and the two teeth are staggered when being close to each other, so that the shoelace can be better gripped.

A fixed shaft is fixedly arranged on the base plate outside the torsion spring mounting shaft on the brake seat, a rotatable pulley is sleeved on the fixed shaft, an anti-falling piece is fixed on the fixed shaft at the upper end of the pulley, and the shoelace can be loosened more easily through the pulley when the shoe is taken off.

And the limiting device assembly comprises a limiting hook fixedly arranged at the bottom of the base plate, wherein the base is provided with an arc-shaped limiting hole and a fixed shaft of the brake seat pulley, and the limiting hook can be hooked at the bottom edge of the arc-shaped limiting hole of the base along with the small-angle rotation of the brake seat. The movable range of the brake seat is limited.

And the protective component comprises an outer wall fixedly arranged at the edge of the base outside the retaining wall of the brake seat, and the outer wall enables the shoelace to move at the top end of the outer wall and not to contact with a gap between the base plate and the base, so that the shoelace is prevented from being clamped between the base plate and the base. The outer wall plays a role in protecting the base elastic sheet and the movable pressing body of the vertical handle.

The invention has the following advantages:

when the shoelace is loosened, only the vertical handle needs to be pushed, the blocked teeth of the brake base plate are blocked by the blocking teeth on the elastic sheet of the base, the stand column is matched with one end part of the stopping hook of the second spring arm of the brake base torsion spring, the anti-slip gear is separated from the stopping hook and can flexibly rotate, and the shoelace is in a loosening state and can be taken off. When the shoelace is tightened, the vertical handle is pushed when the shoe is taken off, so that the shoelace can be easily tightened at the moment, and finally the movable pressing body is pressed.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

Fig. 1 is a structural schematic view of a shoe buckle of the easy-to-pull shoelace of the present invention.

Fig. 2 is a separate view of the brake shoe and the latch of fig. 1.

Fig. 3 is a right side view of fig. 1.

Fig. 4 is a schematic view of the base of fig. 1.

Fig. 5 is a left side view of fig. 4.

Fig. 6 is a schematic view of the brake spider of fig. 1.

Fig. 7 is an exploded right side elevational view of the neutral handle and movable press body of fig. 6.

Fig. 8 is a top view of fig. 6.

Fig. 9 is a schematic view of fig. 1 with the cover plate attached.

Fig. 10 is a bottom view of fig. 9.

FIG. 11 is a schematic view of the post-holding position of the elastic sheet of the present invention.

Fig. 12 is a schematic view of the base of fig. 11.

Detailed Description

Reference is made to fig. 1 and 2 and to fig. 4 and 6. The utility model provides a shoe buckle of easy-to-draw shoelace which characterized in that: comprises the following steps:

the shoe upper fixing device comprises a base 1, a fixing shaft 11 and a fixing device, wherein the base 1 is used for being fixed on a shoe upper, and the fixing shaft 11 vertically and upwardly extends is arranged in the middle of the base 1;

an anti-slip gear 2 is rotatably fixed to the fixed shaft 11.

Referring to fig. 9 and 10, the anti-slip gear top cover is provided with an enlarged anti-slip cover plate 4, the anti-slip cover plate 4 extends to a position close to the top of the base 1 clamping column 12 to form a blocking piece 42 perpendicular to the direction of the base 1, and the edge of the anti-slip cover plate is fixedly provided with a separation fence 41 extending to the direction of the base.

The anti-loosening braking mechanism comprises a braking seat, an elastic top clamping piece and a clamping column 12 fixed on the base 1; the brake seat comprises a base plate 31 which is rotatably fixed on the fixed shaft 11 and clamped between the anti-skid gear 2 and the base 1, and a retaining wall 35 which is fixed on the base plate 31 at one side outside the anti-skid gear 2, wherein the clamping column 12 is arranged on the base 1 at one side of the retaining wall and can be abutted against the retaining wall 35, and the shoelace 100 penetrates out from the position between the retaining wall 35 and the clamping column 12; the inner side of the clamping column 12 is provided with a groove 122 matched with the blocking piece 42 of the anti-falling cover plate 4.

Elasticity top card spare is including fixing torsional spring 32 on the brake block and fixing stand 13 on base 1, and the tail end of this torsional spring 32's first spring arm is equipped with fixed hook 322 and fixes the top and hold 351, the cooperation of second spring arm in 35 inboard fixed slots of barricade between anti-skidding gear 2 and 35 opposite faces of barricade, and the second spring arm is the V font and the tail end is equipped with and anti-skidding gear 2 matched with stopping hook 321, stand 13 passes the base plate 31 between barricade 35 and anti-skidding gear 2 upwards extends the top card on torsional spring 32 second spring arm, seted up on the base plate 31 and cooperated the confession brake block small-angle pivoted and link up the groove with stand 13.

Referring to fig. 1-2 and to fig. 3-4-5, in conjunction with fig. 6, fig. 7-8. The brake seat control mechanism comprises an elastic sheet 16 with elastic capacity arranged on a base 1, wherein the middle part of the elastic sheet 16 is fixedly provided with a long strip-shaped blocking tooth 161 with a triangular cross section, and the tooth surface facing the upright post 13 forms an included angle with the surface of the elastic sheet 16. The outward end of the stop tooth 161 of the elastic piece 16 is fixedly provided with a convex body 162 with a step slope facing the direction of the clamping column. The edge of the bottom of the base plate 31 of the brake seat near the clamping column 12 is fixedly provided with a blocked tooth 311. After the brake block leaves the 12 small-angle rotations of kelly, the quilt of base plate 31 hinders tooth 311 and can be blocked by the tooth 161 that blocks on the flexure strip 16, at this moment, because of the stand 13 on the brake block small-angle rotation back base 1 can cooperate at the stopping hook 321 one end tip of brake block torsional spring 32 second spring arm, stopping hook 321 breaks away from anti-skidding gear 2 promptly, anti-skidding gear 2 can not receive the restriction of stopping hook 321 when the pine or tight shoelace 100, do not need both hands cooperation singlehanded can easily draw the pine or taut shoelace 100 this moment.

A vertical handle 33 is fixedly arranged on the outer side surface of a retaining wall 35 of the brake seat close to the clamping column 12, the vertical handle 33 is a hollow sleeve, a movable pressing body 331 which can only move up and down is sleeved in the sleeve, the movable pressing body 331 is provided with an inverted cone-shaped lower end 3312, the upper end of the movable pressing body 331 is fixedly provided with an enlarged movable pressing body 331 cap 3311, and a contact surface for pressing the movable pressing body 331 by fingers in use is increased; the part of the upper end of the sleeve type vertical handle 33 close to the clamping column 12 extends upwards to form a blocking piece 333 for protecting the cap 3311 of the movable pressing body 331, so that fingers are prevented from contacting the cap 3311 of the movable pressing body when the vertical handle 33 is pushed, and the movable pressing body 331 can normally move in the sleeve of the vertical handle 33; after the blocked teeth 311 of the base plate 31 of the brake shoe are blocked by the blocking teeth 161 on the elastic sheet 16 of the base 1, by pressing the cap 3311 of the movable pressing body 331 in the sleeve of the vertical handle 33, the slope of the inverted cone-shaped lower end 3312 of the movable pressing body 331 will press the step slope of the convex body 162 on the elastic sheet 16 of the base 1, so that the brake shoe will be forced to move towards the direction of the clamping post 12, the pressing force of the elastic sheet 16 and the blocking teeth 161 thereof due to the movable pressing body 331 will be lower than the surface of the base 1, thereby releasing the blocked teeth 311, at this time, due to the elasticity of the torsion spring 32 on the brake shoe, the upright post 13 will automatically fit at the bending part of the second spring arm, the anti-slip gear 2 is blocked by the retaining hook 321 to prevent the anti-slip gear 2 from rotating, and the retaining wall 35 of. The movable pressing body 331 moves away from the elastic piece 16 along with the vertical handle 33 and approaches the clamping column 12. The elastic sheet 16 and the base 1 are provided with a slope 17 for the reverse conical lower end 3312 of the movable pressing body 331 to flexibly pass through.

Refer to fig. 11, fig. 12. A pressing column 163 vertically extends from one end of the outer side of the elastic sheet 16 of the base 1, and the pressing column 163 has the same function as the movable pressing body 331.

Refer to fig. 1 and 2. A tooth 332 is fixedly arranged on one side of the vertical handle 33 close to the clamping column 12, and a tooth 121 is also fixedly arranged on the clamping column 12 corresponding to the tooth, and the two teeth are staggered when approaching, so that the shoelace 100 can be better gripped.

Referring to fig. 1 and 2, fig. 6 and 7. A fixing shaft 34 is fixedly arranged on the base plate 31 outside the mounting shaft 36 of the torsion spring 32 on the brake seat, a rotatable pulley 341 is sleeved on the fixing shaft 34, an anti-drop piece 342 is fixed on the fixing shaft 34 at the upper end of the pulley 341, and the shoelace 100 can be loosened more easily by passing through the pulley 341 when the shoelace 100 is taken off.

Reference is made to fig. 1 and 2 and to fig. 3 and 4 and 5. A protection component, which comprises an outer wall 15 fixed on the edge of the base 1 outside the retaining wall 35, wherein the outer wall 15 makes the shoelace 100 move at the top end thereof without contacting the gap between the base plate 31 and the base 1, thereby preventing the shoelace 100 from being clamped between the base plate 31 and the base 1. The outer wall 15 protects the elastic sheet 16 of the base 1 and the movable pressing body 331 of the vertical handle 33.

Reference is made to fig. 1-4 and to fig. 7-8. And the limiting device component comprises a base 1 provided with an arc-shaped limiting hole 14 and a limiting hook 37 fixedly arranged at the bottom of the base plate 31 at the position of the fixed shaft 34 of the brake seat pulley 341, wherein the limiting hook 37 can be hooked at the bottom edge of the arc-shaped limiting hole 17 of the base 1 along with the small-angle rotation of the brake seat. The movable range of the brake seat is limited.