TWI708714B - Chain retention device for rear derailleur - Google Patents

Abstract

A chain retention device for rear derailleur, wherein the rear derailleur further includes a main derailleur component, includes a swing arm, a guide wheel, an elastic arm, a tension wheel, and an elastic member. The swing arm has one end connected to the main derailleur component. The guide wheel is pivot on the swing arm for free rotation. The elasticity arm has one end pivot on the swing arm. The tension wheel is pivot on elasticity arm for free rotation. And the elastic member has opposite ends urging the swing arm and elastic arm to rotate the elastic arm related to the swing arm in a direction of reducing an included angle between the elastic arm related to the swing arm.

Description

Chain guide of rear derailleur

The present invention relates to the technical field of a transmission installed in a bicycle, and particularly refers to a chain guide of a rear transmission.

Generally, variable speed bicycles usually have at least one transmission mounted on the flywheel of the rear wheel set. The rider can use the transmission to change the speed according to different road conditions. During riding, the gear shift lever can be used to change the speed at the same time, which can facilitate the rider to adapt to different conditions. Road conditions and comfortable riding bicycles.

The conventional transmission has a chain guide, which is used to guide the chain on the flywheel to change the action of different chainrings when shifting, and each of the chainrings has a chain avoiding groove. When shifting, the guide The chain guides the chain to the corresponding chainring, and the chain avoiding groove makes it easier to change the chain to the corresponding chainring; the conventional chain guide structure has a guide wheel, a force wheel, and a set of the guide wheel and the chain With the integrated guide plate structure on both sides of the tension wheel, the rider can use the shift lever to control the chain guide to act and guide the chain to change the gear plate and change the speed.

The above-mentioned conventional guide plate structure is used on bumpy or rugged roads. It is easy for the chain to oscillate too much, so that the holes of the chain are not closely meshed with the teeth of the chainring, which causes the chain to fall off, which is commonly known as The "chain drop" situation; another situation is: when the front and rear chainrings of the bicycle are between the large chainring and the large chainring, the chain will be in a tight state, when the user depresses the pedal in the opposite direction to drive it When the crank is stepped back, it will cause the chain to touch the chain avoiding groove of the chainring and jump down at least one chainring. It will also cause excessive wear of the chain, which increases the cost of maintenance for the rider. And maintenance.

The above situation will make the rider feel bad, especially the general rider is not able to deal with the above-mentioned falling chain situation, and it will make the rider afraid of riding the bicycle.

The object of the present invention is to provide a chain guide of a rear derailleur, which has the effect of keeping the tension of the chain stable at different positions.

Another object of the present invention is to provide a chain guide of a rear derailleur, which can reduce the probability of the chain jumping down by a chain.

In order to achieve the above-mentioned objects and effects, the present invention discloses a chain guide of a rear derailleur, wherein the rear derailleur further includes a main transmission member, and the chain guide includes: a swing arm, one end of which is connected to the main transmission member; The guide wheel is pivoted to the swing arm and can be freely rotated relative to the swing arm; an elastic arm is pivotally connected to the swing arm at one end; a force wheel is pivoted to the elastic arm and can freely rotate relative to the swing arm ; And an elastic member, disposed between the swing arm and the elastic arm, to provide an elastic force to make the elastic arm pivot to reduce the angle between the swing arm and the elastic arm.

In one embodiment, the swing arm has two arms, the two arms are parallel and separated by a predetermined distance; one end of the two arms is connected to the main transmission member; the guide wheel is located between the two arms, A shaft is pivoted on the two arms.

In one embodiment, the elastic arm has two side arms and a connecting arm; the two side arms are parallel and separated by a predetermined distance, and the two ends of the connecting arm are connected to the two side arms; the tension wheel is located on the two arms In between, a shaft is pivoted on the two side arms.

In one embodiment, the elastic arm is pivotally connected to the swing arm by a shaft; the swing arm has a stop part, the elastic arm has a stop part; the elastic part has a torsion spring, and is sleeved on the A shaft, and its two ends are respectively connected to the stop part of the swing arm and the elastic arm.

In an embodiment, the stop portion of the swing arm is a hole provided on the swing arm, and one end of the torsion spring is inserted into the hole.

In an embodiment, the stop portion of the elastic arm has a protrusion, and one end of the torsion spring abuts against the protrusion.

In an embodiment, the stop portion of the swing arm is a plurality of holes provided on the swing arm, and one end of the torsion spring can be inserted into any hole.

The above-mentioned technical means can reduce the chance of the chain falling off due to stepping on the pedal in the opposite direction in the conventional structure, and the torsion spring and the two elastic arms can provide a stable and balanced tension between the chain and each chainring, so that the chain and The chainrings can continue to maintain a stable meshing state to avoid excessive friction between the chain and other components, which will cause the chain to be damaged and need to be replaced. It can also save the maintenance cost of the rider, and further prevent the chain from falling off. A better riding experience.

In the following, according to the objectives and effects of the present invention, preferred embodiments are cited, and the components of the present invention and the combination relationship between the components are described in conjunction with the drawings.

Please refer to Figures 1 and 2. This embodiment discloses a rear derailleur chain guide, which is installed on a bicycle 1; the bicycle 1 has at least a frame 20, a transmission system 40, and a rear derailleur 60.

The transmission system 40 is installed on the frame 20 and includes a front chainring 42, a pair of cranks 44, a flywheel, and a chain 48; the front chainring 42 is mounted on a bottom bracket of the frame 20 at the center of the circle The pair of cranks 44 are installed on the front chainring 42; the flywheel 46 is installed on the rear fork of the frame 20, the flywheel 46 is composed of several different sizes of chainrings (461-466), each of the chainrings ( 461～466) have different numbers and sizes of teeth, which can be used by the rider to change gears according to different road conditions; each of the chainrings (461～466) of the flywheel 46 has a chain avoiding groove, which can assist the The chain 48 performs the conversion between the chainrings (461-466); the chain 48 bypasses the front chainring 42 and the flywheel 46, and meshes with the teeth of the front chainring 42 and the flywheel 46; when riding When a force is applied to the pair of cranks 44, the pair of cranks 44 can drive the front chainring 42, which in turn drives the chain 48 to drive the flywheel 46 to move, so that the bicycle 1 can move; the transmission The system 40 is a conventional structure, and will not be repeated in this embodiment.

The rear derailleur 60 has a main transmission member 62 and a chain guide 64; the main transmission member 62 is installed between the frame 20 and the flywheel 46, and the rider can use a transmission control device to control the main transmission member 62 , Through the chain guide 64 to guide the chain 48 on the flywheel 46 to change different chainrings (461-466).

Please refer to Figures 3 and 4, the chain guide 64 has a swing arm 642, a guide wheel 644, an elastic arm 646, an elastic member 648, and a force wheel 650; the swing arm 642 has Two arms 642a, 642b, the two arms 642a, 642b are arranged in parallel and a predetermined distance apart, one end of the two arms 642a, 642b is connected to the main transmission member 62 (please refer to Figure 2), and the two arms 642a, 642b Both ends of the support arms 642a, 642b have a mounting hole 6422; the support arm 642a has a perforation 6424 and a plurality of positioning holes 6426, which can be installed or fixed by the user; the guide wheel 644 has a mounting hole 6442 A shaft 652 can be used to insert the mounting hole 6442, and the guide wheel 644 can be pivoted to each of the mounting holes 6422 at one end of the two arms 642a, 642b in a rotatable manner, and located between the two arms 642a, 642b The elastic arm 646 is generally an integrated U-shaped structure, with two parallel and two side arms 646a, 646b separated by a predetermined distance and a connecting arm 6462, the two ends of the connecting arm 6462 are connected to the two side arms 646a , 646b, and the two ends of the two side arms 646a, 646b each have a mounting hole 6464, allowing a shaft 652 to be inserted and mounted on one end of the two side arms 646a, 646b with a mounting hole 6464 and the two support arms 642a, 642b are opposite to the mounting hole 6422 at the other end of the guide wheel 644, so that the elastic arm 646 can be pivotally connected to the swing arm 642 with the shaft 652 as a central axis.

In this embodiment, the elastic member 648 has a torsion spring, the torsion spring is sleeved on the shaft 652 passing through the swing arm 642 and the elastic arm 646, and the torsion spring is located on the two arms 642a, 642b The two ends of the torsion spring each have a fixed portion 648a, 648b of a predetermined length, and a side arm 646a of the elastic arm 646 has a stop portion 6466, the stop portion 6466 has a bump, the bump There is a groove for fixing one end fixing portion 648a of the torsion spring to the groove of the protrusion; a supporting arm 642b of the swing arm 642 has a stopping portion 6428. In this embodiment, the stopping portion 6428 has A plurality of fixing holes can be used to fix the torsion spring with respect to the fixing part 648b of the other end of the stop part 6466, and can form a different pre-torque force through fixing holes installed at different positions; the elastic member 648 can Provide an elastic force so that the elastic arm 646 can respond to different road conditions and maintain a stable tension of the chain 48 (please refer to Figure 2); the tension wheel 650 has a mounting hole 6502, and a shaft 652 can be inserted into the mounting hole 6502 The tension wheel 650 is pivoted on the elastic arm 646 relative to the mounting hole 6464 connected to the other end of the swing arm 642 in a rotatable manner.

Please refer to FIG. 5, an included angle A is formed between the swing arm 642 and the elastic arm 646, the elastic arm 646 can use the shaft 652 as an axle to swing freely, and the included angle A can move with the elastic arm 646 In this embodiment, the elastic arm 646 is subjected to the elastic force of the elastic member 648 to limit the included angle A to increase or decrease in a degree interval.

Please refer to Figures 6 and 7, when the rider applies a force to the pair of cranks 44 (please refer to Figure 1), the chain 48 will be driven to move, and the chain 48 will then drive the flywheel 46 If the bicycle 1 (please refer to Figure 1) is activated, the bicycle 1 (please refer to Figure 1) can move due to the above-mentioned actions; wherein when the rider rides on different road conditions, the control device can be operated to control the speed change and change the main speed change member 62 The position of the chain guide 64 further guides the chain 48 to the other chainrings of the flywheel 46. The above action can provide the rider with a better riding experience.

The chain 48 can be guided by the chain guide 64 to the relative position of the flywheel 46; when the chain 48 is at the largest chainring 466 of the flywheel 46, the force required to apply the pair of cranks 44 (please refer to Figure 1) Relatively small, relatively labor-saving (please refer to Figure 6); relatively, when the chain 48 is at the smallest chainring 461 of the flywheel 46, the force required to be applied to the pair of cranks 44 is relatively large, relatively laborious, and the chain 46 will be relatively longer than the length at the largest chainring 466, the main transmission member 62 will be driven to maintain the tension of the chain 48 (please refer to Figure 7); in a nutshell, the chain 48 is at the On different chainrings (461-466) of the flywheel 46, the main transmission member 62 can be driven to maintain the tension of the chain 46.

Please refer to Figures 8 and 9, when the rider encounters a height difference when riding on a rough road, the chain 46 will swing up and down due to the height difference (the dotted line). At this time, the The chain guide 64 can use the shaft 652 connecting the swing arm 642 and the elastic arm 646 as a pivot and provide a point for the elastic arm 646 to swing, and the elastic member 648 (please refer to Figure 3) can provide an elastic Force, the chain 48 can maintain a stable tension when it swings up and down, and continuously maintain a stable meshing state with the front chainring 42 and the chainrings (461-466) of the flywheel 46, so that the chain 48 does not fall off .

Another situation is: when the chain 48 is located at the largest chainring 466 of the flywheel 46, because the chain 48 is located at the chainring of the flywheel 46 and the front chainring 42 will form an offset, the offset can form an effect The force acts in the direction of the smallest chainring 461. When the rider applies the force of the pair of cranks 44 in the opposite direction, the chain 48 is more likely to cause the chain to act on the chain avoiding groove due to the force acting on the chain avoiding groove. The flywheel 46 jumps down by a sprocket; the elastic arm 646 and the elastic member 648 (please refer to Figure 3) of this embodiment can provide an elastic action, so that the chain 48, the front sprocket 42 and the flywheel 46 Each of the chainrings (461-466) can also continuously maintain stable meshing, which can effectively reduce the probability of the chain 48 jumping down a chainring on the flywheel 46.

In this embodiment, by installing each of the shaft and the elastic member, when the rider is on the way in rough road conditions, it can provide the elastic arm with more elastic force and elastic action, and continuously maintain the stable tension of the chain on different chainrings , So that the chain does not fall off; another situation is: when the rider applies a force to the pair of cranks in the opposite direction, this embodiment can effectively reduce the probability of the chain falling off to other chainrings, so that the chain and The chainrings maintain a stable meshing state; the above benefits can provide riders with a better riding experience, and can avoid excessive friction between the chain and the chainrings, which will cause damage to the chain, and save maintenance costs. It also provides a Affordable components for use.

The above-mentioned embodiments are only illustrative of the technology and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with this technology can modify and change the above-mentioned embodiments without violating the technical principle and spirit of the present invention. Therefore, the protection scope of the present invention should be listed in the scope of patent application described later .

1: bicycle 20: Frame 40: Transmission system 42: front chainring 44: crank 46: Flywheel 461～466: Sprocket 48: chain 60: rear derailleur 62: Shifting main component 64: chain guide 642: Swing Arm 642a: Support arm 642b: support arm 6422: mounting hole 6424: Piercing 6426: positioning hole 6428: stop 644: Guide Wheel 6442: mounting hole 646: Flexible Arm 646a: side arm 646b: side arm 6462: connecting arm 6464: mounting hole 6466: stop 648: Elastic 648a: Fixed part 648b: Fixed part 650: Tension wheel 6502: mounting hole 652: Shaft

Figure 1 is a perspective view of a preferred embodiment of the present invention mounted on a bicycle. Figure 2 is a partial perspective view of a preferred embodiment of the present invention mounted on a bicycle. Figure 3 is a perspective view of a preferred embodiment of the present invention. Figure 4 is an exploded view of a preferred embodiment of the present invention. Figure 5 is a side view of a preferred embodiment of the present invention. Figure 6 is a perspective view of a preferred embodiment of the present invention to guide the chain at the first position. Figure 7 is a perspective view of a preferred embodiment of the present invention to guide the chain at the second position. Fig. 8 is a schematic diagram of the function of a preferred embodiment of the present invention on subversive road conditions. Fig. 9 is a partial schematic diagram of the effect of a preferred embodiment of the present invention on uneven road conditions.

64: chain guide

642: Swing Arm

642a: Support arm

642b: support arm

6424: Piercing

6426: positioning hole

6428: stop

644: Guide Wheel

646: Flexible Arm

646a: side arm

646b: side arm

6462: connecting arm

6466: stop

648: Elastic

650: Tension wheel

652: Shaft

Claims (7)

A chain guide for a rear derailleur, wherein the rear derailleur further includes a main gear shift member, and the chain guide includes: a swing arm connected to the main gear shift member at one end, and a stopper at the other end; a guide wheel, It is pivoted at the end of the swing arm connected to the main transmission component, and the guide wheel can freely rotate relative to the swing arm; an elastic arm has a stop at one end, and the swing arm is provided with the The end of the stopping part is pivotally connected; a force wheel is pivoted on the other end of the elastic arm, and the tension wheel can freely rotate relative to the swing arm; and an elastic member, which is a torsion spring, is sleeved on the The shaft is also arranged between the swing arm and the elastic arm, and the two ends of the elastic element are respectively connected to the stop part of the swing arm and the elastic arm to provide an elastic force so that the elastic arm reduces the swing arm and the elastic arm. The direction of the included angle between the elastic arms pivots. The chain guide of the rear transmission according to claim 1, wherein the swing arm has two arms, the two arms are parallel and are separated by a predetermined distance; one end of the two arms is connected to the main transmission member; the guide wheel Located between the two supporting arms, a shaft is pivoted on the two supporting arms. The chain guide of the rear derailleur according to claim 1, wherein the elastic arm has two side arms and a connecting arm; the two side arms are parallel and a predetermined distance apart, and the two ends of the connecting arm are connected to the two side arms; The tension wheel is located between the two supporting arms and is pivoted on the two side arms by a shaft. According to claim 1, the chain guide of the rear transmission, wherein the stop portion of the swing arm is a hole provided on the swing arm, and one end of the torsion spring is inserted into the hole. According to the chain guide of the rear derailleur according to claim 1, wherein the stop portion of the swing arm is a plurality of holes provided on the swing arm, and one end of the torsion spring can be inserted into any hole. According to the chain guide of the rear transmission according to claim 1, wherein the stop portion of the elastic arm has a protrusion, and one end of the torsion spring abuts against the protrusion. According to claim 6, the chain guide of the rear derailleur, wherein the protrusion has a groove, and one end of the torsion spring is located in the groove.

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