GB2381248A

GB2381248A - Bicycle with rear wheel shock absorbing structure

Info

Publication number: GB2381248A
Application number: GB0125397A
Authority: GB
Inventors: Ting-Hsing Chen
Original assignee: Far Great Plastics Industrial Co Ltd
Current assignee: Far Great Plastics Industrial Co Ltd
Priority date: 2001-10-23
Filing date: 2001-10-23
Publication date: 2003-04-30
Also published as: GB0125397D0

Abstract

The bicycle has a cross-bar 11 extending from a head tube 12 past a seat tube 13 to an extension 111 with a depending bracket 14 mounting an upper end 41 of a shock absorber 4 for relative pivoting. A bracket 131 at the bottom of the seat tube 13 mounts a rear wheel fork plate 2 for relative pivoting, the plate having a bracket 21 mounting a lower end 42 of the shock absorber 4 for relative pivoting. The brackets 21, 131 may have raised parts with surfaces complementary to the shock absorber end surfaces for support.

Description

BIKE SHOCK ABSORBER STRUCTURE BACKGROUND OF THE INVENTION (a) Field of the Invention The present invention relates to a bike shock absorber structure, and more particularly, to one that is adapted to the rear frame of a bike.

(b) Description of the Prior Art: As a means of transportation and fitness, a bike provides excellent mobility and even gets more and more popular in recent years. Design of a bike is more diversified to ensure firm and comfortable riding. An absorber presents the optimal solution. Usually, the absorber is adapted to both sides of a front fork of the bike. However, whether a rider feels comfortable depends on the rear frame of the bike, that is, where the seat is located.

Fork absorption is not directly involved in such comfort. The absorber adapted to the front fork may provide some effects but is not the optimal solution in general.

SUMMARY OF THE INVENTION The primary purpose of the present invention is to provide a bike shock absorber structure adapted to the rear frame of the bike. To achieve the purpose, a crossbar extending backward from the head tube after connection to a vertical seat tube further extends for an extension section. An upper bracket is provided to the lower end of the extension section in a proper length and two pivoting tabs forwardly protrudes from the lower end of the seat tube to receive a rear fork plate pivoted to a rear wheel. A lower bracket is fixed to the rear fork plate in relation to the upper bracket

provided on the extension section and an absorber is vertically connected between the upper and the lower brackets.

Upon riding the bike on a rough road, the rear wheel linked to the rear fork plate rises with the pivoting tabs as the turning center, and the absorber provided on the lower bracket of the rear fork plate is compressed relatively to the upper bracket to absorb the on-going shock.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded view of a preferred embodiment of the present invention; Fig. 2 is a cross-sectional view of an assembly of the preferred embodiment of the present invention; Fig. 3 is a cross-sectional view showing how the preferred embodiment of the present invention operates; Fig. 4 is an exploded view of another preferred embodiment of the present invention; and Fig. 5 is a sectional view of an assembly of another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figs. 1, and 2, an extension section (111) in proper length is extended from a crossbar (11) connecting to a head tube (12) of a frame (1) after the crossbar (11) is connected with a vertical seat tube (13). An upper bracket (14) in shape of a staple having its opening facing downward is provided on the lower end of the extension section (111). Two pivoting tabs (131) connected to a rear fork plate (2) in parallel extend forwardly from the lower end of the seat tube (13). A rear wheel (3) is pivoted to the

rear of the rear fork plate (2). A lower bracket (21) with its opening facing upward is fixed to the rear fork plate (2) in relation to the upper bracket (14) provided on the extension section (111). An absorber (4) is vertically provided between the upper bracket (14) and the lower bracket (21) by means of pivoting elements (5). Both ends of the absorber (4) are respectively provided with arc pivoting members (41) and (42).

Upon riding on a rough road as illustrated in Figs. 2 and 3, the rear wheel (3) linked to the rear fork plate (2) rises with the pivoting tabs (131) as the turning center, and the absorber (4) provided on the upper bracket (21) of the rear fork plate (2) is relatively compressed. As the uprising route of the rear fork plate (2) relates to an arc trail, the absorber (4) is completely compressed when the rear fork plate (2) rises to ensure riding comforts by fully absorbing the shock from the road.

As illustrated in Figs. 4 and 5, concave retaining surfaces (141) and (211) are respectively formed on inner sides of the upper bracket (14) and the lower bracket (21) by compromising the arc of the pivoting members (41) and (42) of absorber (4) so to fully engage the ends of the upper and the lower pivoting members (41) and (42) of the absorber (4). Should the surfaces of the upper and the lower pivoting members (41) and (42) of the absorber (4) be flush, the retaining surfaces (141) and (211) can be made flush so to fully attached to both ends of the absorber (4) to increase an area subject to compression force for the absorber (4) to avoid over-concentrated stress on the upper and the lower brackets (14) and (21) and the pivot of the absorber (4).

Upon assembling the absorber (4) as illustrated in Fig. 5, both outer surfaces of the pivoting members (41) and (42) provided on both ends of the absorber (4) are fully attached to the retaining surfaces (141) and (211) provided on the inner sides of the upper and the lower brackets (14) and

(21) to increase the area for subjecting to compression force. Therefore, once the absorber (4) operates, the lower bracket (21) linked to the rear fork plate (2) has its retaining surface (211) to push up the absorber (4) and compress the absorber (4) in relation to the retaining surface (141) on the upper bracket (14) to prevent breakage or deformation at where the absorber (4) pivoted to the upper and the lower brackets (41) and (42), thus indirectly creating a reinforcement for the upper and the lower brackets (41) and (42).

Claims

1. A bike shock absorber structure comprising an extension section extending after connection to a vertical seat tube from a crossbar extending backward from a head tube of a bike; an upper bracket being provided on the lower end of the extension section; two pivoting tabs being protruded forward from the lower end of the seat tube to connect to a rear fork plate pivoted to a rear wheel; a lower bracket being provided on the rear fork plate in relation to the upper bracket on the extension section; and an absorber being provided between the upper and the lower brackets; the rear wheel linked to the rear fork plate rises having the pivoting tabs as a center of turning when the bike is riding on a rough road for the absorber adapted to the lower bracket of the rear fork plate to compress in relation to the upper bracket for absorbing the shock.

2. A bike shock absorber installation as claimed in Claim 1, wherein, retaining surfaces are respectively formed on inner sides of the upper and the lower brackets by compromising the shape of both of the upper and the lower ends of the absorber to create a reinforcement to where both of the upper and the lower brackets are pivoted to the absorber.