US-12617493-B1 - Rear derailleur with damping function

US12617493B1US 12617493 B1US12617493 B1US 12617493B1US-12617493-B1

Abstract

A rear derailleur with a damping function includes a chain guide portion, a movable portion, a resilient member, and a damping assembly. The chain guide portion includes a shaft member engaged with the movable portion, the resilient member, and the damping assembly. The damping assembly includes at least one one-way bearing, an inner ring, an outer ring, a plurality of first damping disks, and a plurality of second damping disks. The one-way bearing is sleeved on the shaft member. The inner ring is located within the outer ring. An inner surface of the inner ring is engaged with the one-way bearing. An outer surface of the inner ring is engaged with the first damping disks. An inner surface of the outer ring is engaged with the second damping disks. A damping material is filled between the first damping disks and the second damping disks.

Inventors

Shang-Feng Lin
CHANG-CHUN KAO

Assignees

TIEN HSIN INDUSTRIES CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20250303

Claims (10)

1 . A rear derailleur with a damping function, comprising a base portion, comprising a frame engaging section and a first pivoting section that are connected to each other; a linkage assembly, comprising a first linkage and a second linkage, wherein an end of the first linkage and an end of the second linkage are pivotally connected to the first pivoting section, respectively; a movable portion, comprising a second pivoting section and a seat body that are connected to each other, wherein the other end of the first linkage and the other end of the second linkage are pivotally connected to the second pivoting section, respectively, so that the first pivoting section, the linkage assembly, and the second pivoting section form a four-bar linkage; the seat body has a shaft bore; a chain guide portion, comprising a chain guide arm and a shaft member connected to the chain guide arm, wherein a guide wheel and a tension wheel are rotatably connected to the chain guide arm, and the shaft member passes through the shaft bore; a resilient member, disposed between the seat body and the chain guide portion and providing a biasing force for a rotation of the chain guide portion; and a damping assembly, comprising an inner ring, an outer ring, a plurality of first damping disks, a plurality of second damping disks, and at least one one-way bearing, wherein the inner ring is located within the outer ring, and an outer surface of the inner ring is engaged with the first damping disks; the outer ring is fixed to the seat body, and an inner surface of the outer ring is engaged with the second damping disks; the first damping disks and the second damping disks are in a staggered arrangement, and a damping material is filled between the first damping disks and the second damping disks; the at least one one-way bearing is engaged with an inner surface of the inner ring; the at least one one-way bearing is sleeved on the shaft member; the shaft member is freely rotatable in a first direction relative to the inner ring through the at least one one-way bearing; wherein when the shaft member of the chain guide portion drives the first damping disks on the inner ring through the at least one one-way bearing to rotate in a second direction opposite to the first direction, the damping material provides damping for the first damping disks to rotate relative to the second damping disks.
2 . The rear derailleur as claimed in claim 1 , wherein the inner surface of the inner ring has a first fitting block, the at least one one-way bearing has a first fitting groove, and the first fitting block is fitted into the first fitting groove.
3 . The rear derailleur as claimed in claim 2 , wherein the outer surface of the inner ring has a second fitting groove, each of the first damping disks has a second fitting block, and the second fitting groove is engaged with the second fitting blocks of the first damping disks.
4 . The rear derailleur as claimed in claim 3 , wherein the inner surface of the outer ring has a third fitting groove, each of the second damping disks has a third fitting block, and the third fitting groove is engaged with the third fitting blocks of the second damping disks.
5 . The rear derailleur as claimed in claim 1 , wherein the damping assembly comprises two seals, and each of the seals is circular in shape and has an inner edge and an outer edge.
6 . The rear derailleur as claimed in claim 5 , wherein a direction of an axis of the shaft member is defined as an axial direction; two first annular grooves are provided on two sides of the inner surface of the outer ring in the axial direction, respectively; two second annular grooves are provided on two sides of the outer surface of the inner ring in the axial direction, respectively; each of the first annular grooves is disposed opposite to each of the second annular grooves; the outer edge and the inner edge of one of the seals are fitted into one of the first annular grooves and one of the second annular grooves, respectively; the outer edge and the inner edge of the other one of the seals are fitted into the other one of the first annular grooves and the other one of the second annular grooves, respectively; each of the seals is slidable between the inner ring and the outer ring.
7 . The rear derailleur as claimed in claim 1 , wherein a first accommodating chamber is formed on a side of the seat body facing the chain guide arm, and the first accommodating chamber surrounds the shaft bore; the damping assembly comprises a casing; the casing is engaged on another side of the seat body away from the chain guide arm; a second accommodating chamber is formed in the casing; the shaft bore communicates with the first accommodating chamber and the second accommodating chamber.
8 . The rear derailleur as claimed in claim 7 , wherein the resilient member is a torsion spring and is located in the first accommodating chamber; an end of the resilient member is engaged with the chain guide arm, and another end of the resilient member is engaged with the seat body.
9 . The rear derailleur as claimed in claim 7 , wherein the shaft member comprises a base shaft and a pivoting shaft; the base shaft is engaged with the chain guide arm and has a shaft rod; the shaft rod rotatably passes through the shaft bore; a threaded hole is provided at an outer end of the base shaft; the pivoting shaft has a first portion, a flange, and a second portion that are coaxially and sequentially connected, the first portion is a bolt and passes into the shaft bore; the flange abuts against a peripheral edge of an end of the shaft bore; a tool hole is provided at an outer end of the second portion.
10 . The rear derailleur as claimed in claim 9 , wherein the at least one one-way bearing is sleeved on the second portion of the pivoting shaft.

Description

BACKGROUND OF THE INVENTION Technical Field The present disclosure relates generally to a derailleur for a bicycle, and more particularly to a rear derailleur with a damping function. Description of Related Art With the popularization of bicycles, the bicycles are no longer just a means for transportation, but important leisure and sports equipment in daily life. In recent years, as the market demand grows, bicycles with shifting functions, such as mountain bikes and road bikes, also are developed accordingly. In general, a chain of the bicycle is tightened through a biasing force provided by a torsion spring of the rear derailleur in a rotation direction so as to maintain a tension of the chain, thereby ensuring that the bicycle could be ridden smoothly. However, when riding on forest trails or cross-country courses, it is common to encounter uneven road surfaces, such as rocks or obstacles. In these cases, the torsion spring of the rear derailleur may suffer from shock and may not be able to restore in time, and the biasing force may disappear instantly or be weakened, resulting in the chain being unable to be tightened. As a result, the problems, such as chain flinging, chain falling off, skipping chain, or making a misstep, may occur. Therefore, the conventional rear derailleur of the bicycle still has room for improvement. BRIEF SUMMARY OF THE INVENTION In view of the above, the primary objective of the present disclosure is to provide a rear derailleur with a damping function so as to avoid the problems such as chain falling, skipping chain or making a misstep when riding a bicycle on uneven roads. The present disclosure provides a rear derailleur with a damping function, including a base portion, a linkage assembly, a movable portion, a chain guide portion, a resilient member, and a damping assembly. The base portion includes a frame engaging section and a first pivoting section that are connected to each other. The linkage assembly includes a first linkage and a second linkage. An end of the first linkage and an end of the second linkage are pivotally connected to the first pivoting section, respectively. The movable portion includes a second pivoting section and a seat body that are connected to each other. The other end of the first linkage and the other end of the second linkage are pivotally connected to the second pivoting section, respectively, so that the first pivoting section, the linkage assembly, and the second pivoting section form a four-bar linkage. The seat body has a shaft bore. The chain guide portion includes a chain guide arm and a shaft member connected to the chain guide arm. A guide wheel and a tension wheel are pivotally connected to the chain guide arm, and the shaft member passes through the shaft bore. The resilient member is disposed between the seat body and the chain guide portion and provides a biasing force for a rotation of the chain guide portion. The damping assembly includes an inner ring, an outer ring, a plurality of first damping disks, a plurality of second damping disks, and at least one one-way bearing. The inner ring is located within the outer ring, and an outer surface of the inner ring is engaged with the first damping disks. The outer ring is fixed to the seat body, and an inner surface of the outer ring is engaged with the second damping disks. The first damping disks and the second damping disks are in a staggered arrangement, and a damping material is filled between the first damping disks and the second damping disks. The at least one one-way bearing is engaged with an inner surface of the inner ring. The at least one one-way bearing is sleeved on the shaft member. The shaft member is freely rotatable in a first direction relative to the inner ring through the at least one one-way bearing. When the shaft member of the chain guide portion drives the first damping disks on the inner ring through the at least one one-way bearing to rotate in a second direction opposite to the first direction, the damping material provides damping for the first damping disks to rotate relative to the second damping disks. The effect of the present disclosure is that the rear derailleur with the damping function could produce the damping effect by the at least one one-way bearing working with the first damping disks, the second damping disks, and the damping material. When the bicycle is ridden on an uneven road surface, the shaft member drives the first damping disks to rotate relative to the second damping disks through the at least one one-way bearing. At this time, the damping material provides damping for the first damping disks to rotate relative to the second damping disks so as to reduce the speed and the degree of the chain guide arm of the chain guide portion rotating in the second direction around the axis of the shaft. In this way, the chain could be quickly returned to an original position after being swung by an external force, so that the problem that the c