Skateboard shock absorber

Abstract

The invention relates to a skateboard shock absorber capable of dampening impacts caused by road irregularities, absorbing vibrations related to rolling, and facilitating changes of direction. It consists of a thick layer of polyurethane (100) with threaded inserts that isolate the deck (300) from the axle block (200). It is positioned in place of the paving stones and allows the axle blocks and deck to be retained without modification. Figure to be published for the abstract: Figure 1C

Description

Title of the invention: Shock absorber for skateboard technical field

[0001] The present invention relates to a device for damping vibrations between two elements.

[0002] It is applicable in particular, but without limitation, in the field of urban mobility, to a shock absorber for skateboards, to absorb shocks from road irregularities and eliminate vibrations related to rolling. Previous technique

[0003] In the current state of the art, patent WO9835872 (Skateboard axle) is known, which represents the origin of the front and rear axle blocks ("truck" in English), composed of polyurethane bushings, which allow for slight cushioning of the irregularities of the terrain depending on the weight of the user and the hardness of the bushings chosen.

[0004] We then find patent WO2019085281 (Single-stage shock absorber mechanism) using spring stages; on this same principle, there is also patent WO2021005516 (Suspension for skateboard) and most recently a new patent WO2024077055 (Suspension system for skateboards).

[0005] These inventions are always complemented by 3.2mm polyurethane cushions (“riser pads” in English) or 6.4mm (“shock pads” in English), to further reduce the shocks generated by irregularities in the terrain. Technical problem

[0006] Prior patents all define new axle block designs, but these are always attached to the deck through a polyurethane cushion a few millimeters thick, using four bolts. Some of the shocks are dampened by the cushion, but the remaining vibrations are transmitted through the four bolts in contact with the axle block base and the deck. Thus, these vibrations are transmitted from the base to the deck, and then from the deck to the user's feet.

[0007] Even if previous devices allow some reduction of vibrations, their use requires changing the equipment and gliding habits. Technical solution

[0008] The invention (100 or variant 100-Bis) is positioned in place of the traditional cushion between the axle block (200) and the board (300), with the same drilling plane, shown in [Fig. 1C] or the variant in [Fig. 2C]. It consists of a semi-rigid material (thermoplastic polyurethane) and has a greater thickness allowing it to absorb more road shocks.

[0009] The invention includes threaded inserts (102A and 102B) with a standard screw thread diameter of 5 mm. On the upper face of the invention, four threaded inserts (102A) are integrated to fix the invention (100) to the board (300), as shown in [Fig. 1C] or [Fig. 2C]. On the opposite face, four more threaded inserts (102B) are also present to fix the axle block base (200) to the invention (100). The inserts (102A) on the upper face are not in contact with the inserts (102B) on the lower face, as shown in [Fig. 1B] or [Fig. 2B]; the length of the screws is adjusted to the height of the invention so that they are not in contact from one face to the other. Since the fixing screws are now only in contact with the invention (100) and the board (300) or the invention (100) and the axle block (200), they no longer transmit the vibrations from the axle block to the board.

[0010] Two additional inserts per face allow for complete compatibility with the standard dimensions of axle blocks known as "Old school" (2.5 x 1.625 inches, i.e. 63.5 x 41.3 mm) and "New school" (2.125 x 1.625 inches, i.e. 54.0 x 41.3 mm), as shown in [Fig.1A] or [Fig.2A].

[0011] Grooves on the upper face of the paving stone, attached to the board, generate an air cushion effect by compressing the polyurethane, which will further isolate the invention from the board to further reduce vibrations.

[0012] The hardness characteristics of polyurethane combined with the thickness of the invention make it possible to facilitate changes of direction.

[0013] According to a first embodiment, shown in [Fig. 1B], the inserts (102A) on the upper face of the invention are aligned with the inserts (102B) on the lower face; this maintains the positioning of the base on the board and therefore does not require any changes to the positioning of the wheels under the board. The thickness of the invention is equal to twice the height of the threaded inserts, plus approximately 2 mm between the inserts on opposite faces. It starts at 14 mm for threaded inserts 5.8 mm long, and increases to 21 mm for inserts 9.5 mm long. This greater height provides better shock absorption.

[0014] In a second embodiment, shown in [Fig. 2B], the axis of the inserts (102A) on the lower face of the invention is offset from the axis of the inserts (102B) on the upper face. The thickness is then equal to the height of the threaded insert plus approximately 2 mm of space; it starts at 8 mm for inserts 5.8 mm long, and reaches 12 mm for inserts 9.5 mm long. This allows for a thinner paving stone and a lower ground clearance.

[0015] According to one embodiment, the threaded inserts can be replaced by nuts; appropriately sized housings on the sides are created to allow the nuts to be integrated into the polyurethane.

[0016] A first manufacturing method is 3D printing using thermoplastic polyurethane (TPU). This material combines characteristics of hardness (Shore hardness of 88) and flexibility (rebound elasticity of 63%); the inserts are then heat-set. TPU has good layer cohesion, increasing the cushioning effect. Filling the invention at a rate of less than 100% further increases the cushioning effect.

[0017] Another method of manufacture is the use of direct molding of the cushion with the positioning of the inserts in the mold. Description of the drawings

[0018] Other advantages, purposes and specific features will become apparent from the following non-limiting description of at least one particular embodiment of the invention, with reference to the accompanying drawings, in which:

[0019] [Fig. 1 A] represents the exploded view of the invention, according to a first mode of a particular implementation of the invention.

[0020] [Fig.1B] represents the cavalier perspective view of the invention, according to a first particular embodiment of the invention.

[0021] [Fig.lC] represents the exploded view of the assembly of the invention, according to a first particular embodiment of the invention.

[0022] [Fig.2A] represents the exploded view of the invention, according to a second embodiment of the invention.

[0023] [Fig.2B] represents the cavalier perspective view of the invention, according to a second particular embodiment of the invention.

[0024] [Fig.2C] represents the exploded view of the assembly of the invention, according to a second particular embodiment of the invention.

Claims

Demands

1. Skateboard shock absorber, consisting of a block and threaded inserts.

2. Skateboard shock absorber according to claim 1, characterized in that the pad (101) is composed of a semi-rigid material, the first method of manufacture of which is 3D printing with thermoplastic polyurethane (TPU) filament.

3. Skateboard shock absorber according to claim 2, characterized in that the pad is composed of thermoplastic polyurethane, the thickness of which allows it to absorb road shocks.

4. Skateboard shock absorber according to claim 3, characterized in that the pad has a composition and thickness which allow it to be compressed to facilitate changes of direction.

5. Skateboard shock absorber according to claim 2, characterized in that the upper face of the pad (101) has grooves allowing an air cushion effect and thus increasing the absorption of vibrations.

6. Skateboard shock absorber according to claim 1, characterized in that the threaded inserts (102A and 102B) are heat-fixed in the block (101).

7. Skateboard shock absorber according to claim 6, characterized in that the positioning of the threaded inserts (102A) and (102B) allows for the attachment of "Old school" type bases and "New school" type bases.

8. Skateboard shock absorber according to claim 6, characterized in that the threaded inserts (102A) of the upper face of the pad (101) are in the same axis as the threaded inserts (102B) of the opposite face and are not in contact with each other which allows the positioning of the axle block to be maintained in the same location under the board.

9. Skateboard shock absorber according to claim 6, characterized, according to a variant, in that the axis of the threaded inserts of the upper face (102A) of the straight block (101-Bis) is offset from that of the threaded inserts (102B) which allows for a lower ground clearance of the board (300).

10. A skateboard equipped with a shock absorber according to any one of the preceding claims, characterized in that the board (300) is fixed by four screws (103A) in the threaded inserts (102A) and the base of the axle block (100) is fixed by four other screws (103B) in the threaded inserts (102B) of the opposite face

11. Skateboard equipped with a shock absorber according to any one of claims 1 to 9 or according to claim 10, characterized in that the screws (103A) fixing the board (300) to the shock absorber (100) are not in contact with the screws (103B) fixing the base of the axle block (200) to the shock absorber (100), the absence of rigid contact between the fixing screws stops the propagation of vibrations related to the rolling of the skateboard.

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