JPH0717452A - Derailer for bicycle - Google Patents

Abstract

PURPOSE:To improve the operability in changing the speed by reducing the difference of the return elasticity in the initial deformation and the final deformation of a shift link mechanism, miniaturize and reduce the weight of a derailer and a speed change operation lever, and easily constitute the saver mechanism. CONSTITUTION:A pantograph link mechanism 7 of a derailer is elastically energized by a return spring 15 provided between two members to be selected to constitute it so as to be displaced in the specified direction, and the return spring is lockingly fitted with two members 4, 5 selected by lockingly fitting parts 16a, 16b to exert the elastic force under the condition where the middle part is separated from each member of the pantograph link mechanism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle derailleur.

[0002]

2. Description of the Related Art For example, a bicycle rear derailleur is
A chain guide that rotatably supports the guide pulley and the tension pulley is provided. The chain guide is supported by a movable member of a shift link mechanism such as a so-called parallelogram pantograph link mechanism, and is swingably supported with respect to the bicycle frame while being elastically biased in a direction to give tension to the chain. ing. By operating a shift operation lever connected to the shift link mechanism via an operation cable, the shift link mechanism is deformed, the chain guide is translated in the hub axis direction, and the chain is a multistage freewheel. You can hang it on the desired sprocket.

As the above-mentioned operation cable, a so-called pull type cable which can normally transmit only the traction force is used. Therefore, the shift link mechanism is always elastically biased in the return direction by the return spring incorporated in the derailleur.

Therefore, when the gear shift operation lever is rotated in the pulling direction of the operation cable, the shift link mechanism is forcibly deformed in a direction in which the elastic force of the return spring is stored. On the other hand, when the gear shift operation lever is turned in the opposite direction to feed out the operation cable, the elastic restoring force of the stored return spring causes the shift link mechanism to return and deform.

As a result, the movable member is reciprocally moved in conjunction with the operation of the gear shift operation lever. As a result, the chain guide is swung in the width direction of the bicycle, and the gear shift operation is performed.

As the return spring, a torsion spring having a winding portion provided in an intermediate portion is usually employed, and the winding portion is inserted into a pin connecting two members of the shift link mechanism which are relatively pivoted. At the same time, both ends of the spring are elastically brought into contact with the two members, respectively.

[0007]

By the way, the return spring is squeezed in accordance with the amount of relative pivotal movement of the two members with which both ends of the spring are brought into contact.

For example, these two members are relatively 45 °
When pivoted, the spring will be squeezed approximately 45 °. The return spring stores an elastic force proportional to the amount of torsional deformation according to Hooke's law. Therefore, when the amount of throttle is large, the difference in the returning elastic force of the return spring between the initial stage and the final stage of deformation of the shift link mechanism becomes large. .

However, it is necessary to impart sufficient frictional resistance (in some cases, click resistance) to the gear shift operation lever against the elastic force of the return spring on the derailleur side so that it is held at a desired turning position. . This resistance needs to be determined with reference to the case where the elasticity of the return spring is the largest. Therefore, when the elasticity of the return spring increases,
The frictional resistance must be increased accordingly,
The rotation resistance of the gear shift operation lever increases. Therefore,
This difference in the return elasticity of the return spring adversely affects the shift operability.

Further, the mechanism for giving the frictional resistance also becomes large, which leads to an increase in size of the gear shift operation lever device itself. Moreover, since the wound portion of the spring is inserted into the connecting pin that connects the members of the pantograph link mechanism, the elastic force of the spring cannot be efficiently applied due to the friction between the return spring and the pin.

In order to alleviate the above problem, it may be possible to increase the number of turns of the coil portion of the torsion spring to extend the entire length of the strand to reduce the difference in elasticity due to the difference in the amount of reduction of the return spring. However, in this case, the coil spring itself becomes very bulky, the workability in assembling is deteriorated, and the derailleur itself to which the return spring is mounted becomes large and the weight also increases.

Further, a so-called saver mechanism may be provided in order to improve the shifting performance of the derailleur.

The saver mechanism stores the elastic force of the spring by pulling the operation cable even when the movable member or the chain guide is prevented from moving in the vehicle width direction when the chain is not traveling. At the same time as the chain starts traveling, the chain is changed to a desired gear position by the elasticity.

Conventionally, in the above-mentioned saver mechanism, an arm member is rotatably pivotally attached to one member constituting the shift link mechanism, and this arm member is provided with a separate spring having a stronger elastic force than that of the return spring. Is generally configured by elastically contacting the arm member with a member to be pivotally attached. If the saver mechanism is provided, when the shift operation cable is pulled while the movement of the movable member is blocked, the arm member is rotated independently of the pantograph link mechanism, and the elastic force of the spring is accumulated. To be done.

In the conventional saver mechanism, in order to elastically bias the arm member, a spring is manufactured separately from the return spring, and this spring is provided between the arm member and the member to which it is pivotally mounted. The arm member is interposed so as to elastically urge the arm member.

Therefore, if the saver mechanism is configured, the number of parts is increased and the assembling work is complicated, which is a factor of increasing the manufacturing cost.

The present invention has been devised under the circumstances described above, and solves the above-mentioned problems of the prior art by reducing the difference in the restoring elastic force between the initial stage and the final stage of deformation of the shift link mechanism. It is an object of the present invention to provide a bicycle derailleur that can improve gear shifting operability, can reduce the size and weight of a derailleur and a gear shifting operation lever, and can easily configure a saver mechanism.

[0018]

In order to solve the above problems, the present invention takes the following technical means.

That is, according to the invention described in claim 1 of the present application, a base member fixed to an appropriate portion of the bicycle frame and a pair of parallel members each having a base end portion rotatably pin-connected to the base member. -Shaped link members, and a parallelogram pantograph link mechanism is constituted by a movable member pivotally connected to the tip ends of these link members, and by swinging and displacing the pantograph link mechanism,
In the bicycle derailleur configured to swing the chain changing member in the vehicle width direction of the bicycle to change gears, the pantograph link mechanism includes a return spring provided between two selected members forming the chain. , While being elastically urged to displace in a certain direction,
The return spring is characterized in that the intermediate portion is separated from the respective members of the pantograph link mechanism, and the elastically acting engaging portions are respectively engaged with the selected two members.

The invention described in claim 2 of the present application is
A base member fixed to an appropriate portion of the bicycle frame, a pair of parallel link members each having a base end portion rotatably pin-connected to the base member, and a swingable end portion of the link members. A parallelogram-shaped pantograph link mechanism is constituted by a pin-connected movable member, and by swinging and displacing the pantograph link mechanism, the chain changing member is swung in the vehicle width direction of the bicycle to perform gear shifting. In the constructed bicycle derailleur, an arm member rotatably supported by an appropriate portion of one member constituting the pantograph link mechanism and to which an end portion of a speed change operation cable is connected, the arm member and the above-mentioned arm member. Provided between the selected member of the pantograph link mechanism and elastically biasing the pantograph link mechanism so as to displace the pantograph link mechanism in a fixed direction. A return spring, the return spring having a middle portion separated from the arm member and each member of the pantograph link mechanism, and an engaging portion that applies elastic force to select the arm member and the pantograph link mechanism. It is characterized in that it is attached to each of the one member.

The invention described in claim 3 of the present application is
The return spring is characterized in that the pair of end portions are rotatably attached to the respective members.

Further, the invention according to claim 4 of the present application is characterized in that the arm member is rotatably supported by one of the pins connecting the respective members of the pantograph link mechanism.

[0023]

According to the invention described in claim 1 of the present application, in the return spring, with the intermediate portion being separated from each member of the pantograph link mechanism, the engaging portion which applies the elastic force is selected. It is attached to each member. Then, the pantograph link mechanism is elastically biased so as to be displaced in a certain direction. For example, when a torsion spring having a winding portion in the middle portion is adopted, only the engaging portion that applies the elastic force of the spring is attached to the two members selected in the pantograph link mechanism, and the winding portion of the spring is The pantograph link mechanism is mounted in a state of being separated from each member without being constrained by each member or a pin connecting these members.

With the above structure, the pantograph link mechanism can be elastically biased so as to be displaced in a fixed direction, and when the pantograph link mechanism is deformed, the entire return spring including the winding portion is entirely pantograph link mechanism. Is displaced relative to.

Since the intermediate portion of the return spring can freely move in accordance with the deformation of the pantograph link mechanism, by selecting the engaging position of the engaging portion of the return spring, each of the pantograph link mechanisms can be selected. The relative rotation amount between the engaging portions of the return spring can be extremely reduced with respect to the relative rotation amount of the member.

As a result, the difference in the return elastic force due to the difference in the throttle amount of the return spring can be made much smaller than that in the conventional case, and the shift operability can be greatly improved.

Further, since the difference in the return elastic force of the return spring is reduced, it is not necessary to increase the frictional resistance of the gear shift operation lever device, and the gear shift operation lever device can be reduced in size and weight.

Further, in the bicycle derailleur according to the present invention, when the return spring is mounted, it is not necessary to insert the winding portion into the pin connecting the respective members of the pantograph mechanism. As a result, the return spring can be assembled very easily, and the man-hours for assembling the derailleur can be reduced to reduce the manufacturing cost.

Further, since the winding portion of the return spring is not inserted into the pin, the friction of this portion is also reduced and the elastic force of the return spring can be efficiently transmitted to the pantograph link mechanism.

Furthermore, the return spring can be attached after the pantograph link mechanism is assembled. Therefore, this return spring can be easily replaced. For this reason, it is possible to replace the race spring that requires severe gear shifting performance with the city cycle spring that requires easy gear shifting performance very easily, and easily change the characteristics of the derailleur itself. You can

According to the invention described in claim 2 of the present application, not only the difference in the return elastic force of the return spring can be reduced, but also the saver mechanism can be easily constructed.

In the derailleur according to the present invention, an arm member rotatably supported by an appropriate portion of one member constituting the pantograph link mechanism and to which an end portion of the shift operation cable is connected is provided, A return spring is provided between this arm member and the selected one member of the pantograph link mechanism. Similar to the invention described in claim 1, in this return spring, the engaging portion that applies the elastic force in a state where the intermediate portion is separated from the arm member and each member of the pantograph link mechanism has the arm member and the pantograph. Each member is attached to one member of the link mechanism.

In the above pantograph link mechanism,
The arm member is held by the elastic force of the return spring in a state of being brought into contact with the one member that supports the arm member. Then, via the arm member, the pantograph link mechanism is elastically biased so as to be displaced in a certain direction.

The arm member is connected to the end portion of the gear shift operation cable, and when the arm member is swung via the gear shift operation cable, the pantograph link mechanism is adapted to correspond to a desired gear position. It can be transformed.

When the shift operation cable is pulled while the movable member of the pantograph link mechanism is fixed, only the arm member is rotated relative to the member supporting it. At this time, the return spring is rotated in a state where the pantograph link mechanism is not deformed, so that the return spring is rotated so as to store the return spring.

As a result, like the conventional structure in which a separate spring is provided, the arm member is rotated so as to store the return spring with the pantograph link mechanism stationary, and the saver function is exerted.

In the saver mechanism having the above structure, it is not necessary to provide a spring between the arm member and the member that supports the arm member. Therefore, the number of parts can be reduced and the manufacturing cost can be reduced.

Further, since it is not necessary to insert the return spring into the pin provided between the arm member and the member supporting the arm member, the assembling work becomes extremely easy,
Assembly efficiency is improved.

Moreover, since the spring for elastically urging the arm member also serves as the return spring, the characteristic of the saver mechanism can be changed very easily by changing the return spring.

In the invention described in claims 1 and 2, the return spring is rotated relative to each member constituting the pantograph link mechanism.
Therefore, like the invention described in claim 3 of the present application,
It is desirable that the end portion of the return spring that exerts the elastic force is rotatably supported with respect to the member to which the return spring is attached.

Further, even if the arm member is rotatably provided on one of the pins connecting the respective members of the pantograph link mechanism as in the invention described in claim 4 of the present application, the same effect is obtained. Can be made.

[0042]

Description of Embodiments Embodiments according to the present invention will be specifically described below with reference to the drawings.

The present embodiment is an application of the present invention to a rear derailleur for a bicycle, that is, a rear derailleur 1 constructed so that the selected one of the multi-stage freewheels is replaced with a chain.

As shown in FIGS. 1 and 10, a rear derailleur 1 to which the present invention is applied is rocked by a base member 3 attached to a vehicle body frame 2 and a connecting pin 11a, 11b at the base end of the base member 3. Movablely connected parallel first link member 4 and second link member 5, and these first link member 4 and second link member 5
A parallelogram pantograph mechanism 7 including a movable member 6 swingably connected by connecting pins 11c and 11d is provided at the tip of the.

As shown in FIG. 10, the movable member 6 has a chain guide 1 serving as a chain changing member which rotatably supports a guide pulley 8 and a tension pulley 9.
0 is swingably supported. When the operation cable T connected to the first link member of the parallelogram pantograph link mechanism 7 is pulled to deform the parallelogram pantograph link mechanism 7, the movable member 6 is swung.

As a result, the chain guide 10 is translated in the axial direction of the hub, the chains are re-engaged, and the gear shift operation is performed.

In the rear derailleur 1 according to this embodiment, as shown in FIG. 1, the torsion spring 15 is provided in a bridging manner between the first link member 4 and the second link member 5.
Is provided.

The torsion spring 15 has a winding portion 15a wound in an arc shape at an intermediate portion, and the winding portion 15a.
The leg portions 15b and 15c extending tangentially from the appropriate portions, and the engaging portions 16a and 16b that are engaged with the first link member 4 and the second link member 5 respectively.

The engaging portions 16a, 16b are formed by bending the tip end portions of the legs 15c, 15b of the return spring 15 in a right angle direction. On the other hand, engaging holes 12a and 12b are provided in the first link member and the second link member. The engaging portions 16a and 16b are the engaging holes 12
The return spring 15 is engaged with each of a and 12b.
Is attached to the pantograph link mechanism 7. A bent portion 16c is provided at an end of the engaging portion 16a, and the bent portion 16c is bent at a right angle to the engaging portion to prevent the engaging portion 16a from falling off from the engaging holes 12a and 12b.

The return spring 15 has its foot portion 15
The first link member and the second link member are attached to the first link member and the second link member 15c, respectively, in a state of giving elasticity in the expanding direction.

The distance between the connecting pin 11a connecting the first link member 4 and the base member 3 and the engaging hole 12a in which the return spring of the first link member 4 is engaged is equal to the second distance. A connecting pin 11b for connecting the link member and the base member, and the engaging hole 12b provided in the second member.
It is set longer than the distance between.

Therefore, when the elastic force of the return spring 15 acts in the direction of expanding the first link member and the second link member, the pantograph link mechanism becomes
The movable member 6 is elastically biased in the clockwise direction (arrow Q direction) in FIG.

In the rear derailleur having the above structure, consider a case where the pantograph link mechanism is deformed from the state shown in FIG. 1 to the state shown in FIG. 2 against the elastic force of the return spring 15.

The return spring 15 is provided with an engaging portion 16 thereof.
The legs 15b and 15c and the winding portion 15a are moved relative to the respective link members in a state where the a and 16b are attached to the first link member 4 and the second link member 5. Therefore, compared to the rotation angle at which the first link member 4 and the second link member 5 are rotated with respect to the base member 3, the legs 15b, 1 of the return spring 15 are compared.
The angle at which 5c is relatively narrowed becomes extremely small.

The above operation will be specifically described with reference to FIG.

When the pantograph link mechanism 7 is deformed in the counterclockwise direction (direction of arrow P) from the solid line state to the dashed line state and the broken line state, the pair of engaging portions 16a and 16b of the return spring 15 are described. The distance between
L _1, L _2, L _3, and the return spring 15 is squeezed together deformation of the pantograph linkage 7. However, since the winding portion 15a of the return spring 15 is separated from each member of the pantograph link mechanism 7, the relative amount of rotation of the legs 15b and 15c of the return spring 15 depends on the first link member 4 and the first link member 4. Base member 3 of two-link member 5
It is extremely small compared to the amount of rotation with respect to. As a result, it is possible to make the difference in the elastic resilience of the return spring 15 between the initial stage and the final stage of deformation of the pantograph link mechanism extremely small.

As a result, the gear shifting operability can be greatly improved, and the miniaturization and weight reduction of the derailleur and gear shifting operating lever device can be greatly promoted.

Further, as shown in FIGS. 1 and 4, the return spring 15 can be mounted after the pantograph link mechanism 7 is assembled. Therefore, the workability of assembling is very good. Therefore, it is possible to improve the assembly efficiency and reduce the manufacturing cost.

Moreover, since the return spring 15 can be attached later, it is possible to easily change to a spring having different characteristics. As a result, it is possible to easily change the characteristics of the transmission.

Further, in the present embodiment, the winding portion 15a of the return spring 15 is not inserted and supported by the connecting pin of the pantograph link mechanism as in the conventional case. Therefore, friction between the connecting pin and the winding portion is also eliminated, and the elastic force of the return spring can be efficiently transmitted to the pantograph link mechanism.

5 and 6 show an embodiment of the invention described in claim 2 of the present application.

In this embodiment, the arm member 20 is rotatably inserted into and supported by the pin 11a connecting the first link member 4 and the base member 3, and the end portion of the arm member 20 is shifted. The inner cable t1 of the operation cable T is connected.

Then, between the intermediate portion of the arm member 20 and the second link member 5, the intermediate portion is separated from the arm member 20 or each member of the pantograph link mechanism as in the first embodiment. The return spring 15 is provided in the closed state.

In the pantograph link mechanism having the above structure, the return spring 15 is held in a state where the arm member 20 is elastically brought into contact with the inner wall portion of the first link member 4.

Therefore, in a state where the movable member 6 can freely swing, when the gear shift operation cable t1 is pulled, the arm member 20 and the first link member 4 are integrated around the pin 11a. Is rotated to
Gear shifting operation is performed.

On the other hand, when the chain stops traveling, the movable member 6 is prevented from swinging.

In this state, when the transmission cable t1 is pulled, the arm member 20 is relatively rotated around the pin 11a with respect to the first link member 4, as shown in FIG. At this time, the arm member 20 is rotated in a direction to store the return spring 15.

As a result, when the chain starts traveling again, the elastic force stored in the return spring 15 causes
The pantograph link mechanism 7 is deformed until the arm member 20 comes into contact with the inner wall portion of the first link member 4, and the saver function can be exhibited.

In the saver mechanism of the above embodiment, since the spring for elastically biasing the arm member 20 is not provided separately, the number of parts can be reduced and the cost can be reduced.

Also, as in the first embodiment, the return spring 15 can be mounted after the pantograph link mechanism 7 and the arm member 20 are assembled, so that the assembly work is extremely simple and the manufacturing process is It is also possible to reduce.

Further, by exchanging the return spring 15, the characteristics of the saver mechanism can be easily changed, and the saver mechanism can be easily constructed according to the number of gears or the type of bicycle. it can.

The scope of the present invention is not limited to the above embodiments. Although the present invention is applied to the rear derailleur 1 in the embodiment, it can also be applied to the front derailleur.

Further, although the return spring 15 is provided between the first link member 4 and the second link member 5 in the embodiment, for example, between the base member 3 and the first link member 4, etc. The return spring according to the present invention may be provided between the members.

Also, in the embodiment, the return spring 1
Although the engaging portions 16a and 16b are formed by bending the tip end portion of 5 at a right angle, and are rotatably attached to the first link member 4 and the second link member, the engaging method is not limited to the embodiment. There is no such thing. For example, the link member may be provided with a rotatable engaging member, and the end portion of the return spring may be fixed to the engaging member. Further, the engaging portion of the return spring may be fixedly provided on the link member.

Further, in the embodiment, the torsion spring having the winding portion 15a in the middle portion is adopted, but, for example,
It is also possible to employ a leaf spring-like substantially U-shaped return spring having no winding portion as shown in FIG. 7 or a leaf spring-like substantially V-shaped return spring as shown in FIG. Further, as shown in FIG. 9, it is possible to employ a return spring that includes a winding portion in which each winding portion is separated from each other in an intermediate portion and causes torsion and bending deformation as well as deformation of the pantograph link mechanism.

Further, not only the winding part of the return spring,
It can also be configured to store elasticity in the foot.

Furthermore, the end portion of the return spring can be configured to be displaced relative to the member to which the return spring is attached. For example, the engaging portion of the return spring is configured to be slidable with respect to the member to which the return spring is attached.

Further, in the second embodiment, the arm member 20 is rotatably supported by the pin 11a connecting the base member 3 and the first link member 4, but the arm member 20 is always supported by the connecting pin. It is not necessary to do so, but for example, a rotating shaft may be separately provided in the intermediate portion of the first link member 4 to support the arm member.

Further, in the embodiment, the engaging portion of the return spring is attached to the member constituting the pantograph link mechanism, but the engaging portion of the return spring is attached to the connecting pin connecting the above members. You can also

Although the return springs of the embodiments are configured to elastically press the respective members of the pantograph link mechanism toward the outside, they are elastic in the direction of pulling the respective members toward the inside of the pantograph link mechanism. The return spring can also be configured so that

[Brief description of drawings]

FIG. 1 is a sectional view showing a pantograph link mechanism of a derailleur according to the present invention.

FIG. 2 is a cross-sectional view showing a state when the link mechanism shown in FIG. 1 is deformed.

FIG. 3 is a diagram for explaining the operation of the derailleur according to the present invention.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a sectional view showing a second embodiment according to the present invention.

6 is a cross-sectional view showing a state when the link mechanism shown in FIG. 5 is deformed.

FIG. 7 is a diagram showing an outline of another embodiment.

FIG. 8 is a diagram showing an outline of another embodiment.

FIG. 9 is a drawing showing an outline of another embodiment.

FIG. 10 is a side view showing the overall configuration of a derailleur to which the present invention is applied.

[Explanation of symbols]

 1 derailleur 2 bicycle frame 3 base member 4, 5 link member 6 movable member 7 pantograph link mechanism 10 chain changing member (chain guide) 15 return springs 16a, 16b engaging portion 20 arm member T speed change operation cable

Claims (5)

[Claims] 1. A base member fixed to an appropriate portion of a bicycle frame, a pair of parallel link members whose base end portions are rotatably pin-connected to the base member, and distal end portions of these link members. A parallelogram pantograph link mechanism is composed of a movable member that is swingably connected to a pin, and by swinging and displacing the pantograph link mechanism, the chain changing member is swung in the vehicle width direction of the bicycle. In a bicycle derailleur configured to shift gears, the pantograph link mechanism is elastically biased to be displaced in a certain direction by a return spring provided between two selected members constituting the pantograph link mechanism. The return spring has an engaging portion that applies an elastic force in a state where an intermediate portion is separated from each member of the pantograph link mechanism. Characterized in that it is respectively engaged wear two members mentioned above selected bicycle rear derailleur. 2. A base member fixed to an appropriate portion of a bicycle frame, a pair of parallel link members whose base end portions are rotatably pin-connected to the base member, and distal end portions of these link members. A parallelogram pantograph link mechanism is composed of a movable member that is swingably connected to a pin, and by swinging and displacing the pantograph link mechanism, the chain changing member is swung in the vehicle width direction of the bicycle. In a bicycle derailleur configured to perform gear shifting, an arm member rotatably supported by an appropriate portion of one member constituting the pantograph link mechanism, and an end portion of a gear shifting operation cable connected thereto It is provided between this arm member and one selected member of the pantograph link mechanism, and displaces the pantograph link mechanism in a fixed direction. And a return spring for elastically urging the return spring, wherein the return spring has an engaging portion for exerting elasticity in a state where an intermediate portion is separated from the arm member and each member of the pantograph link mechanism. A rear derailleur for a bicycle, wherein the rear derailleur is attached to one selected member of a link mechanism. 3. The return spring according to claim 1, wherein an engaging portion that applies an elastic force is rotatably attached to each member. The bicycle derailleur described in. 4. The bicycle derailleur according to claim 2, wherein the arm member is rotatably supported by one of the pins connecting the respective members of the pantograph link mechanism. 5. The bicycle derailleur according to claim 1, wherein the return spring is a torsion spring having a winding portion in an intermediate portion.