JPH0322072Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a bicycle derailleur in which the chain is changed to a selected one of the multi-stage sprockets, and the invention uses a swinging link mechanism that is given an elastic return force. The chain guide member attached to the movable member of the swing link mechanism is forcibly deformed by a wire pulling operation, and the chain guide member attached to the movable member of the swing link mechanism is moved in parallel in the axial direction of the multi-stage sprocket. This relates to a method that reduces the difference between the return force at the beginning of deformation and the return force at the end of deformation.

[Conventional technology and its problems]

This type of derailleur usually has a structure in which a chain guide member is supported via a swing link mechanism such as a so-called parallelogram pantograph link mechanism to a base member fixed to a frame. When the chain guide member is deformed, the chain guide member moves in parallel in the axial direction of the sprocket. In the case of a rear derailleur, the chain guide member is a replacement frame that supports two pulleys, a guide pulley and a tension pulley, around which the chain that is about to engage the multi-stage freewheel is attached to a sprocket on the movable member of the swing link mechanism. It is configured to be rotatably supported while being elastically biased in one direction around a support shaft parallel to the shaft, and in the case of a front derailleur, it is a pair facing inwardly and outwardly so as to sandwich the chain that is about to be hung on the multi-stage chain wheel. A chain guide is attached to the movable member of the swing link mechanism.

When the swing link mechanism deforms, the replacement frame or chain guide moves in the direction of the sprocket axis, thereby displacing the chain that is about to hang on the sprocket in the width direction of the sprocket.
The chain is replaced with a sprocket that corresponds to the position of the replacement frame or chain guide in the sprocket axial direction.

The operation of deforming the above-mentioned swing link mechanism is usually done by
The swinging link mechanism and a speed change lever attached to an appropriate part of the frame are connected by a cable, and the rotational operating force of the speed change lever is transmitted to the swing link mechanism via this cable. Since it is convenient to use a so-called pull-type cable that can only transmit traction force from the viewpoint of ease of wiring and durability, the swing link mechanism is always biased in the return direction by a return spring. This is usually done. Therefore, the cable is connected to the swing link mechanism such that when the cable is pulled, the swing link mechanism is forcibly deformed against the return spring. As a result, when the shift lever is operated to pull the cable, the swing link is forcibly deformed in the direction of accumulating force against the return spring, while when the shift lever is operated in the opposite direction to the above, the cable is pulled. When the swing link is extended, the swing link returns to its original shape due to the elastic return force of the stored return spring. As a result, the movable member supporting the chain guide member is reciprocated in conjunction with the reciprocating movement of the speed change lever.

The above-mentioned return spring is usually produced by inserting a torsion spring into a pin that connects two members that pivot relative to each other among the members constituting the swing link mechanism, and by bringing both ends of the spring into elastic contact with each of the two members. It will be installed. In such a spring mounting structure, when the swing link mechanism is deformed against the elasticity of the spring, the spring is compressed by an amount commensurate with the amount of relative pivoting of the two members. For example, if the two members pivot relative to each other by 45 degrees, the spring will be constricted in an approximately 45 degree torsional direction. According to Hook's law, a spring has a repulsive force that is proportional to the amount of torsional deformation, so if the amount of restriction in the pivoting range of the link mechanism is large, the spring repulsion at the beginning of the link mechanism's deformation and at the end of the deformation. The difference in force increases, which adversely affects shift operability. For example, it is necessary to provide a gear shift lever with sufficient frictional resistance (sometimes click resistance) to resist the elasticity of the return spring on the derailleur side and hold it at the desired rotational position. , it is necessary to determine the time point at which the above-mentioned return spring has the greatest repulsive force as a reference, and therefore the rotational resistance of the speed change lever must be made extremely large. Of course, the difference in stored repulsive force due to the amount of contraction of the return spring can be reduced by increasing the number of turns in the coil part of the torsion spring and extending the overall length of the strands, but in this case the coil spring itself becomes very bulky. This causes problems in that assembly workability deteriorates, and the derailleur itself to which this bulky return spring is attached becomes large and heavy.

This invention was devised under the above circumstances, and by minimizing the change in elasticity of the spring from the initial stage of deformation to the final stage of deformation in the deformation range of the swing link mechanism, the above-mentioned The task is to solve the problems of the conventional example.

[Means to solve the problem]

In order to solve the above problem, in the invention of the present application,
The following technical measures have been taken:

A base member, a parallel first link and a second link pin-coupled to the base member so that one end thereof can swing, and a movable member whose other ends of the first link and the second link are pin-coupled so that they can swing relative to each other. A bicycle derailleur comprising: a swing link mechanism; and a chain guide member attached to a movable member of the swing link mechanism; An actuating member that is rotatably supported around a spindle parallel to the connecting pin of each member and connected to one end of a cable, and the actuating member is connected to a first link between the actuating member and the first link or the second link. Or, a torsion spring is interposed so as to bias the second link in a direction of relative rotation in one direction, and the amount of swing of the first link or the second link is smaller than the amount of rotation of the actuating member. Thus, a regulating means is provided for connecting fixed points on the actuating member and fixed points on a member of the link mechanism other than the member on which the actuating member is supported.

[Effect]

For the sake of simplicity, the actuating member is rotatably supported by a pin connecting the base member and the first link, and one end is hooked to the first link and the other end is hooked to the actuating member by the same pin. Consider the case where a torsion spring is inserted into the sleeve and both ends of the restricting means are connected between selected fixed points on the actuating member and the movable member.

The regulating means has the function of regulating mutual rocking so that the amount of rotation of the first link is smaller than the amount of rotation of the actuating member, and has both ends of the spring engaged with the actuating member and the first link, respectively. Because it is stopped,
When the actuating member is rotated in one direction, the spring is loaded due to the difference in the amount of rotation. Since the regulating means connects the movable member and the operating member to which elastic rotational force is applied by the above-mentioned stored force, the elastic rotational force applied to the operating member is transferred to the regulating means. is transmitted to the movable member via. Therefore, in the swing link mechanism, the elasticity of the stored spring is transmitted to the movable member via the actuating member or regulating means, so that an elastic return force is always applied in one direction. .

Moreover, since a torsion spring is interposed between the first link and the operating member that rotates in the same direction by different amounts with respect to the base member when the swing link mechanism is deformed,
The amount of twist (twist angle) of the torsion spring is smaller than the amount of rotation (angle of rotation) of the actuating member, and therefore the difference in return force between the beginning of rotation and the end of rotation of the actuating member becomes smaller. Therefore, if sufficient return force is applied to the spring to move the chain guide member at the initial stage of rotation of the actuating member, the overall speed can be changed by operating the gear shift lever with a small force. Become.

〔effect〕

As described above, according to the present invention, the difference in the return force in each deformation state of the swing link mechanism is reduced, and as a result, a torsion spring with a relatively small number of turns can be used. As a whole, quick and light gear shifting operations can be performed with a relatively small operating force, and the swing link mechanism can be made more compact.

[Explanation of Examples]

Embodiments of the present invention will be specifically described below with reference to the drawings. The drawings show an example in which the present invention is applied to a bicycle rear derailleur, that is, a derailleur configured so that a chain is replaced with a selected one of a multi-stage freewheel.

As shown in FIG. 1, the derailleur 1 of this example is
It is especially configured so that it can be installed on a bicycle equipped with a bicycle stand 2, such as a women's bicycle or a utility vehicle.

The derailleur 1 basically consists of a base member 3 attached to a vehicle body frame, a parallel first link 7 and a second link 8 that are pivotably connected to the base member 3 at one end with a pin. The swing link mechanism 10 includes a movable member 9 to which the other ends of the first and second links 7 and 8 are swingably pin-joined, and the movable member 9 has a chain guide member 11 attached thereto. be done. The posture of the swing link mechanism 10 is set such that when the swing link mechanism 10 is deformed, the movable member 9 moves in parallel to the width direction of the bicycle, that is, in the case of a rear derailleur, to the width direction of the multi-stage freewheel F.

In this example, the base member 3 is fastened together with the bracket 6 of the stand 2 to the end of the hub axle 5 that is fixedly supported by the fork end 4, and extends forward from the mounting portion so as to avoid the stand 2. It has a shape that hangs downward after being released.

The lower end portions of the first link 7 and the second link 8 are swingably connected to the base member 3 via pins 12 and 13 that are supported inside the lower end of the base member 3 so as to be spaced apart from each other. A movable member 9 is connected to the upper end portions of the first link 7 and the second link 8 via pins 14 and 15, respectively. Pins 12, 13, 1 that connect the base member 3, each link 7, 8, and the movable member 9 to each other
4 and 15 form the vertices of a parallelogram. Therefore, when the swing link mechanism 10 swings in and out with respect to the base member 3, the movable member 9 moves toward the pin 12.
Alternatively, it moves in parallel in the inward and outward directions while drawing an arcuate locus with the pin 13 as the center and the length of the links 7 and 8 as the radius.

In the case of a rear derailleur, the chain guide member 11 is, as shown in FIGS. 1 and 2,
It consists of a replacement frame 18 that supports a guide pulley 16 at the top and a tension pulley 47 at the bottom, and the tension pulley 17 is always given elasticity to move rearward with respect to the movable member 9, while being parallel to the hub shaft 5. It is supported so as to be swingable about a support shaft 19. The chain C is wound around the rear side of the tension pulley 17 and the front side of the guide pulley 16, and then around one of the sprockets s1 to s3 of the freewheel F. Replacement frame 18
is biased as described above, so even if the amount of slack changes when the chain C is replaced with a sprocket of a different diameter on the freewheel F, the tension pulley 17 will elastically move rearward. This slack is removed and appropriate tension is constantly applied to chain C.

Now, reference numeral 20 indicates an operating member rotatably supported by the pin 12 that connects the base member 3 and the first link 7. This is a member into which the operating force of a transfer lever (not shown) is input via the cable W, and the outer cable w is received by an outer cable receiver 21 provided at an appropriate portion of the base member 3.
An end portion of the inner cable w2 extending from the inner cable w2 is fixedly attached. In the illustrated example, an arcuate reel portion 2 centered around the pin 12 is provided around the operating member 20.
2, and by aligning the inner cable w2 along this reel portion 22 and then fixing it, the deflection of the inner cable w2 when pulling the inner cable w2 and rotating the operating member 20 is eliminated. At the same time, the actuating member 20 can be rotated in proportion to the amount of pulling of the cable w2.

A torsion spring 23 is inserted into the pin 12, and one end 23a of the pin 12 is attached to the hooking portion 2 provided on the first link 7 with a certain restriction applied.
4, the other end 23b is hooked to the hook portions 25 provided on the actuating member 20, so that the actuating member 20 is connected to the second link 7 in relation to the first link 7.
It is elastically biased in the direction of arrow q in the figure. This also means that the first link 7 is elastically biased in the direction of arrow L in FIG. 2 in relation to the actuating member 20.

Furthermore, by the regulating means 26 that connects the fixed point A on the actuating member 20 and the fixed point B on the movable member, when the actuating member 20 is rotated, the first link The operating member 20 and the swing link mechanism 10 are linked together so that the amount of rotation (rotation angle) of the rotation member 7 becomes small. In this example, the regulating means 26 is in the form of a link member (hereinafter referred to as a regulating link). That is, the actuating member 2
The regulating link 2 is connected to the pin 27 provided on the arm portion 20a extending upward from the pin 12 at 0, and the pin 15 connecting the movable member 9 and the second link 8.
Both ends of 6 are pivotally connected. Then,
In this example, the hole 28 in the regulation link 26 for accommodating the pin 27 has a constant elongated hole shape, so that the regulation link 26 has a maximum distance between the two pins 27 and 15 to which it is connected. In addition to regulating them to a certain extent, they are allowed to come close to each other.

Next, the operation of this embodiment will be explained.

When the actuating member 20 is rotated in the direction of the arrow p from the state shown in FIG. Although it tries to rotate in the direction of arrow L, the amount of rotation is suppressed by the restriction link 26 to be smaller than the amount of rotation of the actuating member 20. Therefore, the arrow p at the end 23b of the spring 23
Since the amount of rotation of the end portion 23a of the spring in the direction of the arrow L is smaller than the amount of rotation in the direction, as the actuating member 20 is rotated in the direction of the arrow P, an added stored force is applied to the spring 23. In this way, the above spring 23 causes the swing link mechanism 10 to always move in the direction of the arrow T, and the actuating member 20 to always move in the direction q.
A return force is applied in each direction.

Therefore, by rotating the gear shift lever in one direction, the cable w2 is pulled against the above return force,
When the actuating member 20 is rotated in the direction of arrow P in FIG. 2, the swing link mechanism 10 is swing-deformed in the direction of arrow L, and as shown in FIG. Moving inward in the direction, chain C
is replaced with the large diameter sprocket s3 side. At this time, additional elasticity is stored in the spring 23. On the other hand, when the gear shift lever is rotated in the opposite direction to the above and the cable w2 is let out, the additional elasticity of the spring 23 is released, and the swing link mechanism 10 returns to deformation in the direction of arrow T from the state shown in FIG. Accordingly, the actuating member 20 also rotates back in the q direction. As a result, the movable member 9 or the replacement frame 18 moves outward in the hub axial direction, and the chain C moves to the small diameter sprocket s.
Can be replaced on the 1st side.

On the other hand, in this example, the hole 2 that accommodates the pin 27 is
8 is a long hole with a constant length, and the regulation link 2
6 allows the pin 27 on the actuating member 20 and the pin 15 on the movable member to be close to each other, so that even if the movement of the movable member 9 is locked while the bicycle is stopped, for example, as shown in FIG. , cable w2
By pulling the actuating member 20, the actuating member 20 can be rotated in the direction of the arrow p. Also at this time, only the end portion 23b of the torsion spring is rotated in the aperture direction and this spring stores additional force, so that the first link 7
A biasing force in the direction of arrow L is acting on . Therefore, when the bicycle starts moving and the movable member 9 is unlocked, the swinging link mechanism 10 is automatically deformed in the direction of the arrow L by the amount allowed by the regulating link 26 due to this urging force, as shown in FIG. The state shown is reached, and the chain C is changed to the larger diameter sprocket side.

As is clear from a comparison of FIGS. 2 and 4, the amount of rotation of the actuating member 20 during the transition from the state of FIG. 2 to the state of FIG.
The amount of twist at both ends 23a, 23b of 3 is extremely small. The change in the amount of twisting of the torsion spring 23 is considerably smaller than the amount of swinging of the first link 7 with respect to the base member 3. . This means that even if a torsion spring 23 is used that has a relatively small number of turns in its coil portion, it is possible to reduce the difference in return force between the initial stage of deformation and the final stage of deformation of the swing link mechanism. However, this means that it is possible to simultaneously reduce the size of the swing link mechanism due to the size reduction of the torsion spring and to reduce the frictional force to be applied to the gear shift lever.

Of course, the scope of this invention is not limited to the above-described embodiments. First, in the embodiment, the operating member 20 is supported by the base member 3, but the swing link mechanism portion is in an inverted relationship with the structure shown in FIG. is supported, and along with this, the torsion spring 23
By arranging the restriction links 26 as appropriate, the same effect as in the above embodiment can be achieved.

Furthermore, in the embodiment, a pin 12 connecting the actuating member 20 to the outer first link 7 and the base member 3 is used.
, and the swing link mechanism 10 is always aligned with the arrow T.
The structure is so-called a top-normal type in which the direction returns to the top side, but the swing link mechanism 10 portion is left-right symmetrical with the structure shown in FIG. A torsion spring is mounted between the actuating member 20 and the second link 8 so that the actuating member 20 is biased counterclockwise, supported by a pin 13 connecting the link 8;
When the regulating link 26 is interposed between the actuating member 20 and, for example, the pin 14, the swing link mechanism always returns to the low side, resulting in a so-called low normal type. In this case, the regulating link 26 is larger than the second link 8 compared to the amount of counterclockwise rotation of the actuating member in FIG.
It is arranged so that the amount of counterclockwise rotation is small.

Further, in the embodiment, the actuating member 20 is supported by the pin 12 and configured as a top normal type, but the biasing direction of the torsion spring is reversed, that is, the actuating member 20 is supported by the first link 12. In relation to this, the swing link 7 can be elastically biased in the direction of the arrow p in FIG. 2 so that the swing link 7 is always resiliently biased in the L direction, thereby making it low-normal. In this case as well, the regulating means 26 rotates the first link 7 in the direction of the arrow q in comparison with the amount of rotation of the actuating member 20 in the direction of the arrow q in FIG.
The actuating member 20 is rotated so that the amount of rotation in the direction is small.
and a link component other than the base member.

Furthermore, although the regulating link 26 as the regulating means in the illustrated example has its integral hole 28 as a long hole,
This hole 28 need not be an elongated hole to achieve the purpose of the present invention. Further, in the illustrated example, the regulating means is in the form of a link member, but it does not need to be in such a form, and may also be constituted by, for example, a cam mechanism.

Furthermore, the front derailleur is constructed by fixing the base member to the sheet pipe near the multi-stage chain wheel and attaching the chain guide member, which consists of a pair of inner and outer guide plates that sandwich the chain that is about to hang on the chain wheel, to the movable member. .

[Brief explanation of drawings]

Fig. 1 is an overall side view of one embodiment of the present invention;
The figure is a view taken along the - line in Fig. 1, Fig. 3 is a view shown in the - line arrow view of Fig. 2 with the second link omitted, and Figs. 4 and 5 explain the operation of this example. FIG. 1 is a view corresponding to the line arrow view of FIG. 1... Derailleur, 3... Base member, 7...
First link, 8... Second link, 9... Movable member, 10... Swinging link mechanism, 2... Operating member,
23...Torsion spring, 24...Regulating means.

Claims (1)

[Claims for Utility Model Registration] A base member, a parallel first link and a second link that are pivotally connected to the base member with a pin at one end, and the other ends of these first and second links swing relative to each other. A bicycle derailleur comprising an oscillating linkage having a movable member pinably coupled thereto, and a chain guide member attached to the movable member of the oscillating linkage, the selected member of the oscillating linkage comprising: an actuating member rotatably supported around a support axis parallel to the connecting pins of each member of the swing link mechanism and connected to one end of a cable; and between the actuating member and the first link or the second link. a torsion spring interposed to urge the actuating member to rotate relative to the first link or the second link in one direction; A bicycle characterized by comprising a regulating means for connecting a fixed point on the actuating member and a fixed point on a member of the link mechanism other than the member on which the actuating member is supported so that the amount of rocking of the two links is small. Derailleur for.