Skateboard track structure

Abstract

The present invention relates to a track structure for a skateboard, which utilizes a cylindrical needle roller bearing to provide axial support along the longitudinal direction of a pivot shaft, thereby enabling smooth steering angle operation based on weight shifting. The structure is characterized in that an upper through-hole is provided on a support plate, the lower end of which opens at an upper sliding contact surface and is inserted through the upper portion of the pivot shaft. A lower through-hole is provided on a swinging portion coaxially with the upper through-hole, the upper end of which contacts the upper sliding contact surface and is opened and is inserted through the lower portion of the pivot shaft. An expanded diameter portion is provided in the lower through-hole to accommodate a cylindrical needle roller bearing externally fitted to at least the lower shaft portion of the pivot shaft, thereby axially supporting the lower shaft portion of the pivot shaft using the cylindrical needle roller bearing.

Description

Technical Field

[0001] The present invention relates to a track structure of a skateboard, and more particularly to a structure in which a cylindrical needle bearing is used to axially support a pivot in the longitudinal direction, thereby enabling a steering angle operation based on body weight movement to be smoothly performed. Background Art

[0002] In the past, the present applicant proposed the following structure in the track structure of a skateboard in Japanese Patent Application No. 2004-81757: in the track structure of a skateboard having a support member that supports the track rotatably from a middle position to the left and right directions and can apply force to the middle position in a reset manner, the support member is composed of a base plate fixed on the deck, and a support plate pivotally mounted on the base plate in a manner that can be rotated to the left and right directions and fixes the track so as to be detachable, and a connecting rod piece is pivotally mounted between the base plate and the support plate, and when the support plate is rotated from the middle position to the left and right directions, the support plate is reset to the middle position by the rebound force of an elastic member such as a coil spring compressed by the connecting rod piece.

[0003] In the above structure, the pivot shaft that passes through the table and the support plate and pivots the support plate rotates around the axis of the pivot shaft in the through hole. However, when a force other than an axial force acts on the pivot shaft, there is a problem that excess friction occurs.

[0004] In addition, in the track structure of the skateboard of WO-A1-2011 / 128944, a track structure is proposed in which an elastic block can be used to reset the sleeve to the middle position during a steering angle operation in which the sleeve is automatically reset by body weight movement. A structure that does not use a coil spring is proposed, but since the ring supporting the pivot is supported by the elastic block, it is difficult to stably support the pivot.

[0005] On the other hand, in the skateboard trolley disclosed in U.S. Publication No. 2002 / 125670 (U.S. Patent No. 6793224), a collar is inserted into the through-holes of the fixed frame and the pivot frame, a screw is inserted through the collar to serve as a pivot, and a flat bearing such as a thrust needle bearing is provided on its pivot surface to enable smooth rotation.

[0006] Similarly, in WO2016 / 203076 (Japanese Patent No. 6444542), when the bolt is rotated as a rotating shaft, the bolt can be smoothly rotated relative to the rotating shaft through a bearing system consisting of two washers and a thrust needle roller bearing and a second shaft needle bearing system consisting of another two washers and a thrust needle roller bearing.

[0007] In these structures, although the rotation of the rotary shaft in the thrust direction is stable, it is still difficult to achieve sufficient stability to support the load applied in the radial direction.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-81757

[0011] Patent Document 2: WO-A1-2011 / 128944

[0012] Patent Document 3: U.S. Patent Publication No. 2002 / 125670

[0013] Patent Document 4: WO2016 / 203076 Summary of the Invention

[0014] Problems to be solved by the invention

[0015] The problem to be solved by the present invention is to provide a track structure of a skateboard, in which the track structure of the skateboard applies load to the pivot that passes through the table and the support plate and causes the support plate to pivot from various directions through the movement of the user's body, but by arranging a needle bearing along the axial direction of the pivot, even if a load is applied in a direction perpendicular to the rotation axis, it can rotate smoothly and stably in the radial direction.

[0016] Solutions to Problems

[0017] In order to solve the above-mentioned problems, the present invention provides the invention of claim 1.

[0018] A track structure for a skateboard, comprising a support plate fixed to a deck and a swinging portion pivotally mounted on the support plate and having a track portion, the track structure of the skateboard having a coil spring, the coil spring supporting the swinging portion in a manner that enables it to rotate leftward and rightward from a middle position of the track portion and applying force in a manner that enables it to return to the middle position, characterized in that:

[0019] An upper through hole is provided on the support plate for inserting the upper side of the pivot.

[0020] A lower through hole is provided on the swing portion on the same axis as the upper through hole and is inserted through the lower side of the pivot.

[0021] The lower through hole is provided with an enlarged diameter hole portion, and the enlarged diameter hole portion accommodates a cylindrical needle bearing externally fitted on at least the lower shaft portion of the pivot shaft.

[0022] The lower shaft portion of the pivot shaft is axially supported by a cylindrical needle bearing.

[0023] In the invention of claim 2, the pivot is composed of a collar inserted through the upper through-hole and the lower through-hole aligned on the same axis, and a fixing bolt inserted through the collar.

[0024] Effects of the Invention

[0025] Conventionally, there were no S-shaped cylindrical bearings for axially supporting the radial load of the pivot shaft. In the thrust direction, two flat bearings were used, with the pivot shaft or a collar being sandwiched between the two bearings, and the bearings were rotated around the pivot shaft.

[0026] Therefore, there is a disadvantage of generating excess friction when a force other than the vertical direction is applied. However, by adding a cylindrical needle bearing for axial support midway in the longitudinal direction of the pivot, the swing part can be rotated smoothly by the user's weight shift and stability can be ensured.

[0027] Description of the drawings

[0028] Figure 1 It is a cross-sectional view of the rail structure of the skateboard of Example 1.

[0029] Figure 2 This is the side view.

[0030] Figure 3 This is the exploded perspective view.

[0031] FIG4(a) is a perspective view of the track viewed from the rear.

[0032] FIG4(b) is a perspective view of the track viewed from the front.

[0033] FIG5(a) is a bottom view showing the lower sliding surface of the table.

[0034] FIG5(b) is a top view showing the upper sliding surface of the swinging portion.

[0035] Figure 6 It is a partial cross-sectional view illustrating the position of the first thrust bearing on the sliding contact surface between the table and the swing portion.

[0036] Figure 7 This is a partially enlarged view showing the positions of the needle roller bearing and the second thrust bearing.

[0037] Figure 8 This is the track structure of the skateboard of Example 2. DETAILED DESCRIPTION

[0038] The present invention supports the pivot of the swinging part in a radial direction by passing through the platform fixed on the deck and the swinging part of the support track (truck) in an up and down manner, and supports the pivot of the swinging part in a radial direction in a cylindrical needle bearing. The swinging part is displaced by the user's weight, and the coil spring is bent in a repulsive manner to automatically reset the steering angle to the middle position. In this track structure, the rotational stability of the steering angle operation of the swinging part is achieved.

[0039] Example 1

[0040] [Track structure]

[0041] Hereinafter, a first embodiment of the rail structure of a skateboard according to the present invention will be described with reference to the accompanying drawings.

[0042] Figures 1 to 7 The rail structure 1 of the illustrated embodiment is composed of a support plate 2 fixed to the deck D and a swing portion 10 pivotally mounted on the support plate 2 and having a rail portion 20 .

[0043] The track structure 1 of the first embodiment is used as a rear wheel device of a skateboard in the illustrated example, but in the present invention, it can be used on the front wheel side or on both the front and rear wheel sides.

[0044] [Supporting platform]

[0045] The support plate 2 is composed of a base portion 3 having a plurality of threaded holes for fixing to the deck D of the slide, and a bearing base 4 formed integrally with the base portion 3 (see FIG. Figure 1 、 Figure 3 ).

[0046] [Base]

[0047] The base portion 3 is set to be substantially flush with the deck D, and has a bottom portion 3a for fixing to the deck D using threaded screws, and a window hole 3b formed in the center of the end portion of the bottom portion 3a.

[0048] [Bearing base]

[0049] The bearing base 4 is a portion that axially supports the upper portion of the fixing bolt 18 formed on the side of the support plate 2. The upper end is inclined and recessed in a manner that descends away from the deck D, and a roughly circular upper sliding contact surface 5 is formed at the lower end to connect with the lower sliding contact surface 13 of the swinging part 10.

[0050] An upper through hole 6 for a fixing bolt 18 is formed in the approximate center of the bearing base 4 , and a receiving portion 7 for fitting a bolt head is formed on the upper surface side of the bearing base 4 , the receiving portion 7 being hexagonally recessed in plan view above the upper through hole 6 .

[0051] [Sliding surface]

[0052] Here, if Figure 6As shown schematically, the upper sliding contact surface 5 and the lower sliding contact surface 13 are formed on the upper sliding contact surface 5 with an inner ring protrusion 5a having a small diameter centered on the axis of the upper through hole 6 and consisting of a downward flat surface, and an outer ring recess 5b having a large diameter concentric with the inner ring protrusion 5a and consisting of a flat surface. The lower sliding contact surface 13 is formed with an inner ring convex portion 13a having a small diameter centered on the axis of the lower through hole 14 and consisting of an upward flat surface, and an outer ring recess 13b having a large diameter concentric with the inner ring convex portion 13a and consisting of a flat surface.

[0053] Furthermore, if the upper through-hole 6 and the lower through-hole 14 are aligned so that the upper sliding contact surface 5 and the lower sliding contact surface 13 overlap, the front end surfaces of the inner ring protrusion 5a and the inner ring convex portion 13a are aligned, and the outer ring concave portion 5b and the outer ring convex portion 13b are aligned.

[0054] On the inner ring protrusion 5a, a plurality of holes k1 opening on the upper sliding contact surface 5 are formed in a row in a ring shape at equal intervals with the axis as the center (14 in the illustrated example), and a plurality of holes k2 are also formed in a row in a ring shape at equal intervals with the axis as the center on the inner ring protrusion 13a on the lower sliding contact surface 13.

[0055] Thus, even when the upper and lower inner ring protrusions 5a and 13a come into contact with each other, the contact area is narrowed, enabling smooth rotation.

[0056] Similarly, in the outer ring recess 13b, a plurality of holes k2' opening on the lower sliding contact surface 13 side are protrudingly provided in a row in an annular shape at equal intervals around the axis (20 in the illustrated example), and in the outer ring recess 5b on the upper sliding contact surface 5 side, a plurality of holes k2 are similarly recessed in a row in an annular shape at equal intervals around the axis (see Figures 5, Figure 6 ).

[0057] [First thrust bearing]

[0058] Therefore, the outer ring recess 5b of the upper sliding contact surface 5 and the outer ring recess 13b of the lower sliding contact surface 13 are fitted through the first thrust bearing, and the inner ring protrusion 5a of the upper sliding contact surface 5 and the inner ring protrusion 13a of the lower sliding contact surface 13 are aligned.

[0059] Furthermore, the first thrust bearing 7 is interposed seamlessly in the gap formed between the outer ring recess 5b and the outer ring recess 13b.

[0060] The first thrust bearing 7 is composed of an upper washer 7a, a central thrust needle roller bearing 7b, and a lower washer 7c.

[0061] By sandwiching the first thrust bearing 7 between the upper and lower outer ring recesses 5 b and 13 b , friction between the sliding contact surfaces 5 and 13 can be reduced.

[0062] Furthermore, the contact area between the upper and lower outer ring recesses 5a, 13a and the washer is also narrowed, enabling smooth rotation (see Figure 6 ).

[0063] [Swinging part]

[0064] Next, the swing portion 10 is composed of a rotating base 11 pivotally mounted corresponding to the bearing base 4 , and a rail portion 20 integrally formed behind the rotating base 11 and supporting the axle of the sleeve W.

[0065] [Bottom through hole]

[0066] As described above, the upper through-hole 6 and the lower through-hole 14 formed in the rotating base 11 of the swinging portion 10 are aligned on the same axis and function as one through-hole by being arranged vertically.

[0067] Here, the upper portion of the lower through hole 14 has the same diameter as the upper through hole 5, but from slightly below to the lower end, it becomes an enlarged hole portion 14' having a larger diameter than the upper through hole 6 and continues to the lower end.

[0068] [Needle roller bearings]

[0069] The enlarged diameter hole 14 ′ is configured to have a size that allows the cylindrical (radial) needle roller bearing 8 to be accommodated outside the collar 15 without any gap.

[0070] In the illustrated example, a needle bearing with a retainer is used as the needle bearing 8 , but any needle bearing may be used as long as it can support the pivot in the radial direction.

[0071] In this manner, the collars 15 are inserted in series through the upper through-holes 6 and the lower through-holes 14 that form a series, and the fixing bolts 18 serving as pivots are inserted through the collars 15 .

[0072] Furthermore, the needle roller bearing 8 that axially supports the collar 15 in the radial direction is inserted into the enlarged diameter hole portion 14 ′ of the lower through hole 14 before the collar 15 is inserted.

[0073] Furthermore, the lower end of a bolt 18 protruding downward from the lower through-hole 14 is fastened by a nut 19 via the second thrust bearing 16 .

[0074] [Second thrust bearing]

[0075] At the end of the through hole 14 below the above-mentioned swinging part 10, between the lower end of the cylindrical needle bearing 8 and the nut 20, a small-diameter annular second thrust bearing 16 is provided on the lower end step 15a of the ring 15 in order to reduce friction during sliding so that the hole portion is hooked.

[0076] Here, the second thrust bearing 16 is composed of an upper washer 16 a , a central thrust needle roller bearing 16 b , and a lower washer 16 c .

[0077] Furthermore, the upper washer 16a of the second thrust bearing 16 is in contact with the lower end of the needle roller bearing 8, and the lower washer 16c is in contact with the upper surface of the nut 19 fastened to the lower end of the fixing bolt 18 via the thrust needle roller bearing 16b (see FIG. Figure 7 ).

[0078] [Track platform]

[0079] Next, the rotating base 11 extends in the longitudinal direction to form a rail base 21 of the rail portion 20 .

[0080] The rail base 21 includes a pivot hole 27 opened on the lower surface and a hole 28 penetrating vertically and for inserting the master pin 26 .

[0081] [Railway Department]

[0082] The rail portion 20 includes a yoke 22 extending horizontally in a direction perpendicular to the traveling direction and having sleeve mounting shafts 22 a fixed to both left and right ends. The sleeve W is rotatably supported on the sleeve mounting shafts by nuts or the like.

[0083] The yoke 22 has a tongue-shaped hanger 23 at its center that protrudes laterally from the side of the yoke body. The hanger 23 is clamped from the upper and lower sides by two upper and lower bushing rubbers 25 made of an elastomer such as polyurethane rubber. The main pin 26 is inserted into a bolt hole opened at the center position of these components and is fastened at the lower end by a nut and a washer.

[0084] The yoke 22 is elastically supported by the kingpin 26 in a state where the yoke 22 is sandwiched between upper and lower surfaces thereof by bushing rubbers 25 .

[0085] Meanwhile, the yoke 22 is provided with a pivot 24 intersecting the kingpin 26 at a predetermined angle. The front end of the pivot 24 is inserted into a pivot hole 27 via a rubber bush or the like, thereby being rotatably supported.

[0086] Next, on the rear inner surface of the swing portion 10 , a housing portion 30 is formed by left and right side walls and a rear wall extending left and right, and the coil spring S is fitted therein.

[0087] In addition, an adjustment bolt 31 having a threaded front end is threadedly coupled to the center of the rear wall 30a of the storage portion 30. The adjustment bolt 31 extends longitudinally in the center of the storage portion 30 and has a knurled head 31a protruding outward from the rear wall 30a.

[0088] The adjusting bolt 31 extends through the central hollow of the coil spring S in the housing portion 30 . A square plate-shaped nut 32 is screwed onto the front end of the adjusting bolt 31 so as not to rotate in the housing portion 30 .

[0089] Therefore, by rotating the head portion 31 a of the adjusting bolt 31 , the plate-shaped nut 32 can be threaded forward and backward along the axial direction of the adjusting bolt 31 .

[0090] The plate-shaped nut 32 abuts against the front end of the coil spring S, compressing the coil spring S together with a link piece 33 to be described later so as to be resilient.

[0091] Next, the link piece 33 is installed between the base plate 2 and the swing portion 10 .

[0092] The connecting rod piece 33 is composed of a plate with a roughly L-shaped cross-section. The front end of the long piece 33a is pivotally mounted on a protruding shaft 34 fixed on the upper surface of the bearing base 4. A hole 34 is penetrated in the bent short piece 33b. The coil spring S is covered in the above-mentioned storage portion 30. The above-mentioned adjustment bolt 31 is inserted through the position connected to the rear end of the coil spring S, and the rear end of the connecting rod piece 33 is pivotally mounted.

[0093] Therefore, if the head 31b of the adjustment bolt 31 is rotated in the tightening direction, the coil spring S clamped between the plate nut 32 and the end 33b of the connecting rod piece 33 is gradually compressed by the forward movement of the connecting rod piece 33 toward the plate nut 32. If it is rotated in the opposite direction, the compression is gradually weakened by the retreat of the plate nut 32, so that fine adjustment of the elastic force can be performed.

[0094] Example 2

[0095] In the above-mentioned embodiment 1, the case where the needle roller bearing 8 is composed of a cylindrical shape with the same cross section is exemplified. However, in the present invention, Figure 8 As shown, the bearing surface of the needle roller bearing 8' may also be conical.

[0096] In the illustrated example, a tapered surface 15 b is formed on the side of the substantially lower half of the collar 15 that is received in the lower through-hole 14 and gradually decreases in diameter downward.

[0097] The needle roller bearings 8 are arranged obliquely along the tapered surface 15 b of the collar 15 in a tapered posture with a width narrowing downward, thereby forming a conical bearing.

[0098] This prevents the swing portion 10 from rotating irregularly, and enables smoother shaft support.

[0099] The other structures are the same as those of the first embodiment, and therefore their description is omitted.

[0100] The present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of not changing the essential parts of the present invention.

[0101] Explanation of symbols

[0102] 1—track structure, 2—support table, 3—base, 4—bearing base, 5—upper sliding contact surface, 5a—inner ring protrusion, 5b—outer ring recess, 6—upper through hole, 7—first thrust bearing, 8—needle roller bearing, 10—swinging part, 11—rotating base, 13—lower sliding contact surface, 13a—inner ring protrusion, 13b—outer ring recess, 14—lower through hole, 14′—expanded diameter hole part, 15—ring, 15a—small diameter step part, 16—second thrust bearing, 18—fixing bolt, 19—nut, 20—track part, D—deck, S—coil spring, W—sleeve.

Claims

1. A track structure for a skateboard, comprising a support base fixed to a deck and a swinging portion pivotally mounted on the support base via a pivot and having a track portion, the track structure comprising a coil spring that supports the swinging portion so that it can rotate leftward and rightward from a center position of the track portion and applies force so that it can return to the center position. The track structure of the skateboard is characterized in that: An upper through hole is provided on the support plate, the lower end of which is opened at the upper sliding contact surface and is inserted through the upper side of the pivot. A lower through hole is provided on the swing portion on the same axis as the upper through hole. The upper end of the lower through hole is opened in contact with the upper sliding contact surface and is inserted through the lower side of the pivot. The lower through hole is provided with an enlarged diameter hole portion, and the enlarged diameter hole portion accommodates a cylindrical needle bearing externally fitted on at least the lower shaft portion of the pivot shaft. The lower shaft of the pivot is supported by a cylindrical needle bearing. The pivot is composed of a collar inserted through an upper through hole and a lower through hole aligned on the same axis, and a fixing bolt inserted through the collar. The lower part of the collar is formed into a tapered shape with a diameter gradually decreasing downwards. The cylindrical needle roller bearing housed in the enlarged diameter portion of the lower through hole is composed of a tapered needle roller bearing fitted onto at least the lower shaft portion of the pivot shaft.

2. The track structure of the skateboard according to claim 1, characterized in that: An inner ring protrusion with a small diameter and an outer ring recess with a large diameter concentric with the inner ring protrusion are formed on the upper sliding contact surface of the supporting plate with the upper through hole as the center. An inner ring protrusion with a small diameter and an outer ring recess with a large diameter concentric with the inner ring protrusion are formed on the lower sliding contact surface of the swinging part with the lower through hole as the center. Circular holes with bottoms are respectively formed in the inner ring protrusion and the outer ring recess at equal intervals and arranged in an annular shape with the axes of the upper and lower through holes as the center. When the inner ring protrusion of the supporting plate and the inner ring convex portion of the swinging part are brought into contact without a gap, a first thrust bearing is provided in the gap formed between the outer ring recess of the supporting plate and the outer ring recess of the swinging part, which is clamped by washers up and down.

3. The track structure of the skateboard according to claim 1 or 2, characterized in that: A second thrust bearing is provided between the lower end of the needle roller bearing and a nut threadedly engaged with the lower end of the fixing bolt, the second thrust bearing being sandwiched between upper and lower portions by washers.

4. The track structure of the skateboard according to claim 3, characterized in that: A small-diameter step portion for hooking the second thrust bearing is formed at the lower portion of the collar.

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