JPH0147357B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bicycle derailleur, in particular, a four-link mechanism configured by a movable member having a base member, two link members, and a chain guide,
The present invention relates to a bicycle derailleur in which the movable member is moved forward relative to the base member by a pulling operation of an operating wire and moved backward by a return spring to perform speed change.

Generally, this type of derailleur applies rotational resistance to the derailleur operation lever that overcomes the return spring to stop the chain guide at a predetermined position and maintain a predetermined gear position.

By the way, when the gear position is set using the operating lever, the movement of changing the chain on the derailleur is not transmitted to the driver, so conventionally,
A positioning plate having a number of recesses corresponding to the number of gears is provided on one of the four structural members constituting the quadruple link mechanism, and another member that moves relative to this member is provided with the recesses. holding a locking body that engages with the recess, and during the relative movement, the locking body engages with one of the recesses to determine a gear shift position, and the locking body engages with the recess. It has been proposed that the movement of the chain change in the derailleur can be read by the click feeling when the chain is changed.

However, when changing gears using the operating wire, especially when pulling the operating wire to change the chain from a small diameter sprocket to a large diameter sprocket, it is difficult for the operator, especially an inexperienced operator, to change the chain from a small diameter sprocket to a large diameter sprocket. In some cases, the operation may be stopped before the set position without accurately matching the position set by the positioning mechanism, so that the locking body of the positioning mechanism accurately engages with the desired recess. If the chain stops near the boundary between the recessed parts, for example, and the chain is guided by the chain guide, it may come into contact with the sprocket to be replaced during replacement, causing noise or causing damage to the sprocket and chain. There was a problem with unexpected wear.

Therefore, it was desired to be able to automatically change the chain to the sprocket, without the chain remaining in contact with the sprocket, even if the operation wire was operated incorrectly, such as when the amount of operation was insufficient. .

Therefore, the present invention was invented in view of the above points, and the purpose is to prevent the number of gears from being read by the click feeling provided by the positioning mechanism, but when the operation wire is operated incorrectly and the amount of operation is insufficient. To provide a derailleur that allows the chain to be reliably replaced with a sprocket even if something happens.

Accordingly, the present invention includes a four-link mechanism consisting of a movable member having a base member, two link members, and a chain guide, and a positioning mechanism for setting the position of the chain guide, and the mechanism includes a positioning mechanism that sets the position of the chain guide, The movable member is moved forward with respect to the base member and moved back with a return spring to perform a speed change, and a member that moves relative to each other and independently of the two members provided with the positioning mechanism. The wire or an outer tube that guides the wire is supported, and this member is movable within a certain range with respect to another member that moves relative to the member, and after the member moves within a certain range, the positioning mechanism It is characterized by being made to operate as if it were activated.

That is, in a derailleur equipped with a positioning mechanism, if the chain comes into contact with the sprocket due to unauthorized operation when operating the operating wire, the chain tension of the chain is used to forcibly move the movable member. This made it possible to move the chain and replace it with the sprocket.

Embodiments of the derailleur of the present invention will be described below with reference to the drawings.

What is shown in the drawing is a rear derailleur, and its basic structure is as shown in Figures 1 and 2.
The four-link mechanism A pivots on the fixed member 1, that is, the four-link mechanism A consists of four members: two link members 3, 4 parallel to the base member 2, and the movable member 5, and the above-mentioned Fixed member 1
is fixed to the fork end of the bicycle, and the base member 2 of the quadruple link mechanism A is fixed to the fork end of the bicycle.
is supported by the fixed member 1 via the horizontal shaft 6 so as to be freely swingable.

Further, the base member 2 is provided with a pair of mounting pieces facing each other on one side, and the link members 3 and 4 are pivotally connected to these mounting pieces via a pair of pins 7 and 8. At the free ends of the link members 3 and 4, via a pair of pins 9 and 10,
The movable member 5 is pivotally mounted.

This movable member 5 has a similar shape to the base member 2, and has mounting pieces facing each other on one side thereof, and the two pins 9 and 10 described above are attached to this mounting piece, and the link member 3, 4, and a chain guide having a guide pulley (not shown) and a tension pulley 12 on the other side via a horizontal shaft 11 extending in the same direction as the horizontal shaft 6. A tool 13 is attached to be rotatable within a certain range, and the swinging of the link members 3 and 4 causes the movable member 5 to move parallel to the base member 2 between the high speed position and the low speed position shown in FIG. It moves like this.

Also, a chain guide 1 attached to the movable member 5
3 consists of the guide pulley and tension pulley 12, and a hanging frame 14 that rotatably supports these pulleys. We support them. Further, the rotation range of this hanging frame 14 is regulated by a stopper 15, and a tension spring 1 wound around the horizontal shaft 11 is used.
6, it is biased in the direction of arrow X in FIG. The tension spring 16 is for applying tension to the chain guided by the guide pulley and the tension pulley 12, and the force of the tension spring 16 causes the movable member 5 to move in the direction of the low speed position. You will be given the power to

Further, the quadruple link mechanism A configured as described above is provided with a return spring 17 to bias the chain guide 13 toward the small diameter sprocket, and has recesses 18 of the same number as the number of gears. The recessed part 1
A positioning mechanism 20 is provided which includes a locking body 19 that engages with any one of the elements 8 and 8.

In the embodiment shown in FIGS. 1 to 4, in the known derailleur constructed as described above, the pin 7 that pivots one link member 3 of the quadruple link mechanism A to the base member 2 is Operation arm 21 that swings independently of the quadruple link mechanism A
The operation wire W or the outer tube O that guides the wire W is supported at the free end of the arm 21, and the connection between the operation arm 21 and the base member 2 in the quadruple link mechanism A is supported. The return spring 17 is interposed in the spring 17, and one end of the spring 17 is brought into contact with a stopper 21a projecting from the operating arm 21, and the other end is brought into contact with a stopper 2a projecting from the base member 2. , while biasing the operating arm 21 in the direction of arrow Y in FIGS. 2 and 4, the recessed portion 18 of the positioning mechanism and the pin Attaching a positioning plate 23 having an arc-shaped guide hole 22 centered at 7,
A storage plate 2 is attached to the pin 7 that supports the operating arm 21.
The locking body 19 of the positioning mechanism 20 and the engagement pin 25 extending in the same direction as the pin 7 are supported on the energy accumulating plate 24, and the energy accumulating plate 24 A power storage spring 26 is interposed between the power storage plate 24 and the link member 3 to bias the power storage plate 24 toward the link member 3.
is provided with a control hole 27 that receives the engagement pin 25 and allows the operating arm 21 to move only within a certain range with respect to the engagement pin 25.
is inserted, and the positioning mechanism 20 is operated after the operating arm 21 has moved within a certain range. In the above configuration, the operating arm 21 extends one end of the pin 7 outward and is fixed to the extended end, so that it can swing together with the pin 7. One end of the operating wire W is fixed to the end via a fixture 28, and the return spring 17 is bent by operating the operating wire W, so that the operating arm 21
It is done as if by shaking. Further, the control hole 27 provided in the operating arm 21 is formed as a circular hole having a larger diameter than the engaging pin 25, as shown in FIG.
This is done by moving only within a certain range. The control hole 27 may be formed as an elongated circular hole centered on the pin 7, or may be formed as a concave notch. , it is only necessary that the engagement pin 25 be moved within a certain range.

Further, the positioning plate 23 is connected to the quadruple link mechanism A.
, and its intermediate portion is connected to the pins 7 and 8.
One end of this positioning plate 23 is directed toward the movable member 5 side, the recessed part 18 is provided on the inner surface of the end, and the other end is made to stand up, and the said positioning plate 23 is fixed to the upright part. The outer tube O is supported via the support 29.

Furthermore, the energy storage plate 24 prevents the operation wire from moving even when the shift resistance acting during the shift operation is greater than the normal resistance, that is, the shift resistance when the chain is moving, such as when the chain is not moving. By operating W, the four-link mechanism A is swung together with the operating arm 21 to switch to a desired gear position in advance, and when the large gear shift resistance is released, that is, when the chain starts to move,
The movable member 5 is moved to the gear position set by the positioning mechanism 20 by the restoring action of the energy storage spring 26, and in the case of normal gear shift resistance, the energy storage spring 26 moves the link member 5 to the gear position set by the positioning mechanism 20. It oscillates in unison with 3. Therefore, the energy storage plate 24 is not necessarily required.

Further, a plurality of recessed portions 18 of the positioning mechanism 20 are provided at predetermined intervals along the rocking locus of the link members 3 and 4 that are displaced during gear shifting and according to the amount of movement of the link members 3 and 4. Yes, also
The locking body 19 is formed of a rolling element and is biased toward the recessed portion 18 by a spring 30.

In the figure, reference numeral 31 is an adjustment screw for adjusting the position of the chain guide 13 relative to the base member 2, which is set by the positioning mechanism 20.

Next, the operation of the derailleur constructed as above will be explained.

What is shown in FIGS. 2 and 5 is a state in which the movable member 5 is at a high speed position, and when the operating wire W is pulled from this state, the return spring 17 whose one end is in contact with the operating arm 21 first releases. When bent, only the operating arm 21 swings within the swing range set by the control hole 27, as shown in FIG. Within this swing range, the movable member 5 and the positioning mechanism 20 do not operate, but the operating arm 21
The return spring 17 is disconnected from the link member 3 by this swing, and as a result, the movable member 5 can freely move toward the large diameter sprocket with respect to the base member 2.

When the operating wire W is further pulled from this state, the end of the control hole 27 hits the engaging pin 25, and from then on, the swinging of the operating arm 21 causes the energy storage plate 24 and the link members 3, 4 to This tracking swing causes the movable member 5 to move toward the large diameter sprocket and the positioning mechanism 20
is activated. And this positioning mechanism 2
The intermediate position where the locking body 19 of No. 0 crosses the boundary between two adjacent recesses 18 to the next adjacent recess, that is, the chain guided by the chain guide 13 reaches the large diameter sprocket. When the pulling operation of the operating wire W is stopped at a position where the operating wire W contacts but is not lifted, in the conventional derailleur, the locking body 19 of the positioning mechanism 20 moves into the desired recessed part 18.
As shown in the imaginary line B in FIG.
The chain stops at a position beyond the a side, and the chain remains in contact with the sprocket, and the contact of the chain with the sprocket causes noise, but in the configuration described above, the movable member 5 is free. Therefore, even if the operation of the operation wire W is stopped at the above-mentioned position, the chain tension acting on the movable member 5 causes the movable member 5 to move to the sprocket side to be replaced. It moves within the swing range. Therefore, the chain that comes into contact with the large diameter sprocket is caught on the teeth of the large diameter sprocket, and is lifted up and reliably replaced with the sprocket. At this time, as shown by the solid line in FIG.
can be placed at the position set by the positioning mechanism 20. Also, depending on the amount of traction operation of the operating wire W, the chain may come into contact with the sprocket and be lifted up and be replaced by the sprocket, but if the amount of traction operation is insufficient at this time, the chain The inner link plate will come into contact with the replaced sprocket. Therefore, if the operation of the operating wire is stopped at this position, a noise will be generated, but in the configuration described above, the movable member 5 is moved by the chain tension acting on the movable member, as in the case described above.
Since it swings within the swing range, the chain guide 13 can be placed at a position set by the positioning mechanism 20.

The above configuration uses the operating arm 21 that swings independently of the quadruple link mechanism A, and the energy accumulating plate 24 that can swing integrally with the link member 3, and the energy accumulating plate 24 and the base member Positioning plate 2 fixed to 2
A positioning mechanism 20 is provided between the base member 2, an operating arm 21 is supported on the pin 7 on the base member 2 side, and a return spring 17 is interposed between the operating arm 21 and the base member 2. Operation arm 21
Although a control hole 27 is provided in the control hole 27 and an engagement pin 25 that is inserted into the control hole 27 is provided in the energy accumulating plate 24, other configurations may be made as shown in FIGS. 7 to 17.

What is shown in FIGS. 7 and 8 includes a base member 2,
A positioning mechanism 20 is provided between the pin 7 and a power accumulating plate 24 which is pivotally supported, and the other configurations are the same as those shown in FIGS. 1 and 2. in this case,
A positioning plate 23 having the recessed portion 18 is provided on the energy storage plate 24, and a holding cylinder 32 holding the locking body 19 is provided on the base member 2.

Further, in the one shown in FIGS. 9 and 10, a positioning mechanism 20 is provided between the base member 2 and the link member 3.
In addition, the energy storage plate 24 is pivotally supported on the pin 8 on the base member 2 side, and the outer cylinder O is supported on the energy storage plate 24. In this case, a positioning plate 23 having the recessed portion 18 is provided on the base member 2, a holding cylinder 32 holding the locking body 19 is provided on the link member 3, and the positioning plate 23 is provided on the link member 3.
3 is provided with a guide hole 22 for the engagement pin 25.

11 and 12, the operating arm 21 is supported by the pin 10 on the movable member 5 side, and a return spring 17 is interposed between the operating arm 21 and the movable member 5. At the same time, the outer cylinder O is supported on the operating arm 21, and the pin 1 is
0, a positioning mechanism 20 is provided between the holding plate 33 and the base member 2 to support the energy accumulating plate 24 and the retaining plate 33, and to connect the retaining plate 33 and the accumulating plate 24 to each other. It is designed to be interlocked by a dowel pin 25. In this case, the recessed part 1
8 is integrally formed with the base member 2, and a holding cylinder 32 holding the locking body 19 is attached to the holding plate 33. Also, the positioning plate 23 has the engaging pin 25. A guide hole 22 is provided.

In addition, the configuration shown in FIGS. 13 and 14 eliminates the need for the energy storage plate 24, and provides a positioning mechanism 20 between the base member 2 and the link member 3.
The link member 3 is provided with the engagement pin 25. In this case, the positioning plate 23 having the recessed portion 18 is formed integrally with the base member 2, and the holding cylinder 32 holding the locking body 19 is attached to the link member 3.

Note that when the energy storage plate 24 is not used, although not shown, the operating arm 21 is supported by the pin 10 on the movable member 5 side, and the operating arm 21 and the movable member 5 are connected.
A return spring 17 is interposed between the link member 4 and the movable member 5, and a positioning mechanism 20 is provided between the link member 4 and the movable member 5. Alternatively, a positioning mechanism 20 may be provided between the link members 3 and 4, and
Other configurations may be configured in the same manner as in the case of FIGS. 13 and 14.

Further, in the case shown in FIGS. 15 and 16, the operation arm 21 is not required, and the operation wire W is connected to one of the link members 3 and 4.
is fixed via a fixture 28, and the control hole 27 is provided at the end of the link member 3 on the side of the movable member 5, and the pin 9 is passed through the control hole 27.
The link member 3 is movable within a certain range with respect to the movable member 5, and the energy storage plate 24 is pivotally supported on the pin 8 on the base member 2 side, and the outer cylinder O is attached to the energy storage plate 24 by a support 29. Along with supporting through
A positioning mechanism 20 is provided between the energy accumulating plate 24 and the other link member 4, and a energy accumulating/returning spring 34 is wound around the pin 8, and one end of the spring 34 is inserted into the intermediate portion of the link member 3. It is engaged with a side surface, and the other end is engaged with a stopper 35 provided on the energy storage plate 24. In this case, when the operating wire W is pulled, only the link member 3 swings within the swinging range set by the control hole 27, as shown in FIG. The end of the hole 27 hits the pin 9,
Thereafter, the other side link member 4 follows the swinging movement of the one side link member 3, and the positioning mechanism 20 operates.

In the case of FIGS. 15 and 16, the energy storage plate 2
Line of action Z of operation wire W from oscillation center O ₁ of 4
When the length of the perpendicular line from the pivot point _O2 of the link member 3 to the base member 2 to the line of action Z is L, the length l is such that l<L. and L are set. Therefore, now,
If the force (moment) of the energy storage/returning spring 34 is M, the force F ₁ required for the energy storage plate 24 to overcome the spring 34 and swing is F ₁ =M/l. Also, the link member 3, in other words, the movable member 5
The force F ₂ required to overcome the spring 34 and move is F ₂ =M/L, and the lengths l and L are l<L, and the lengths l and L are the link. Since there is almost no change even when the members 3 and 4 swing, the relationship between the forces F ₁ and F ₂ is always F ₁ > F ₂ , and the shift resistance that acts during the shift operation is equal to or less than the normal resistance. In this case, the link members 3 and 4 necessarily swing before the energy accumulating plate 24 swings, and the speed change operation can be performed without displacing the energy accumulating plate 24. Further, when the speed change resistance is larger than the normal resistance, the energy storage plate 24 swings clockwise in FIG. 16 against the spring 34, and energy is stored in the spring 34. By releasing the gear, the desired gear position can be operated using the accumulated force.

In addition, when configured as shown in FIGS. 15 and 16,
The control hole 27 may be provided in the link member 4 and the positioning mechanism 20 may be provided between the energy storage plate 24 and the link member 3.
, and the outer cylinder O may be supported by the link member 3 or 4 on the side where the control hole 27 is provided.
Further, the control hole 27 may be provided on the movable member 5 side.

In addition, in the embodiment described above, the operation arm 21
When using the operating arm 21, the operating arm 21 is supported using the connecting pins 7 or 10 of the members constituting the quadruple link mechanism A.
Alternatively, in addition to providing the control hole 27 in the operating arm 21, the engaging pin 25 may be provided in the operating arm 21, and the control hole 27 may be supported by a separate pin.
may be provided on the positioning mechanism 20 side member.

Further, the swing range of either the operating arm 21 or the link members 3, 4 by the control hole 27 may be the amount of movement necessary for the chain to move onto the sprocket after the chain contacts the sprocket.

Further, the positioning mechanism 20 has the recessed portion 18 in one of the four structural members constituting the quadruple link mechanism A or in an intermediate member supported by the member.
, and the locking body 19 may be provided on another member that moves relative to this member or on an intermediate member that supports this member.

Furthermore, although the derailleur described above is a rear derailleur, it can be similarly applied to a front derailleur.

As described above, according to the present invention, although the number of gears can be read by the click feeling provided by the positioning mechanism, especially when changing the chain from a small diameter sprocket to a large diameter sprocket, the amount of operation becomes insufficient and the positioning mechanism If the position of the chain guide tool set by the positioning mechanism does not reach the desired setting position and the chain is not moved enough and the chain is in contact with the sprocket, or the chain is meshed with the sprocket on one side. The movable member is automatically moved by the chain tension that acts on the chain even when the
The chain guide can be moved to a desired setting position. Therefore, even if the operation wire is operated incorrectly and the amount of operation is insufficient, the chain will not continue to be in contact with the sprocket, and the noise caused by the chain contacting the sprocket will be reduced. The noise can be eliminated.

[Brief explanation of drawings]

Fig. 1 is a front view of the derailleur of the present invention, Fig. 2 is a bottom view, Fig. 3 is a partially enlarged front view, Fig. 4 is a partially enlarged bottom view, and Fig. 5 is a view of the derailleur when only the operating arm is swung. FIG. 6 is an explanatory diagram showing the positional relationship between the recessed part of the positioning mechanism and the locking body, and FIGS. 7 to 17 are partially enlarged explanatory diagrams showing another embodiment. 2... Base member, 3, 4... Link member, 5
...Movable member, 13...Chain guide, 17...
Returning spring, 20... Positioning mechanism, 21... Operating arm, W... Operating wire, O... Outer tube.

Claims (1)

[Claims] 1. A four-link mechanism consisting of a movable member having a base member, two link members, and a chain guide, and a positioning mechanism for setting the position of the chain guide, and the movable member can be moved by pulling an operating wire. The wire or supporting an outer tube that guides the wire;
A bicycle derailleur characterized in that this member is movable within a certain range with respect to another member that moves relative to the member, and the positioning mechanism is activated after the member moves within a certain range.