JPS61150884A - Front derailer for bicycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a front derailleur for a bicycle, which is configured to be able to change gears by changing the chain onto a selected sprocket of a multi-stage cheno wheel (front gear) of a bicycle. Concerning things that have been improved so that the cheno can be incorporated into the game.

[Conventional technology]

-A front derailleur has a movable member that is moved in parallel by a control mechanism such as a pantograph link mechanism with respect to a base member that is fixed by means such as a band clamp attached to the lower part of the seat pipe. The movable member is provided with a pair of guide plates that face each other with a predetermined interval left and right so as to sandwich the chino running toward the chino wheel. The pair of guide plates are moved outward in parallel by operating the chino hooked on the inner small-diameter sprocket to the outer large-diameter sprocket. Then, the inner surface of the inner guide plate forcibly pushes the running chain outward, and as a result, the chain is hooked onto the large-diameter sprocket next to the sprocket it is currently hooked on, and as this sprocket rotates, it is completely unlatched. Can be replaced. On the other hand, when changing the chain from the outer large-diameter sprocket to the inner small-diameter sprocket, the control mechanism is operated to move the pair of guide plates inward in parallel. Then, the outer guide plate pushes the running chain inward, causing the chain to drop into the small diameter sprocket next to the sprocket it is currently hooked on, and the chain to be hooked is changed.

[Problem to be solved by the invention]

By the way, the spacing between the pair of guide plates of the conventional general front derailleur mentioned above is set to be more generous than the width of the chenno, and the spacing is usually fixed at a constant value. It is. The reason why the distance between the pair of guide plates is set wider than the width of the chino is that
This is to prevent the chino from coming into contact with the guide plate and causing abnormal noise or causing unnecessary wear and tear on the guide plate even if the guide plate swings from side to side for some reason. However, as mentioned above, there are advantages to setting and fixing the distance between the pair of guide plates wider than the width of the chino, but recently, the use of three or more chino wheels, Moreover, since the outer diameter of the innermost small-diameter sprocket has been made considerably smaller than the other sprockets, the following problems have occurred. That is, when changing the chaino to the smallest diameter sprocket, the chaino may jump over the smallest diameter sprocket and fall further inside the smallest diameter sprocket. When changing the chain from a large-diameter sprocket to a small-diameter sprocket, as described above, the chain running in front of the large-diameter sprocket is forcibly pushed inward by the outer guide plate, causing the chain to separate from the large-diameter sprocket. let The detached cheno is dropped into the small diameter sprocket on the inside, and the cheno can be rerouted. When changing the chain from a small diameter sprocket to a large diameter sprocket, it is better to push the chain towards the large diameter sprocket and use this pushing force to hook the chain to the large diameter sprocket. When changing the chain, the mechanism for changing the chain is thick (different. In other words, when changing the chain from a large diameter sprocket to a small diameter sprocket, the guide plate does The only thing that can be done is to force the hanging chain from the large-diameter sprocket. Therefore, if the pair of widely spaced guide plates are forcefully moved inward, the chain, which has been forced to dislodge the large-diameter sprocket by the outer guide plate, will be removed. may jump over the innermost, smallest diameter sprocket.The present invention was devised under the above circumstances. The object of the present invention is to provide a front derailleur that can fit around the width of the chain and prevent the chain from falling off when changing from a large-diameter sprocket to a smallest-diameter sprocket, as seen in conventional front derailleurs. shall be.

[Means for Solving the Problems] In order to solve the above problems, the bicycle front derailleur of the present invention has the following configuration. That is, a pantograph link mechanism consisting of a base member, an outer link member and an inner link member whose proximal ends are pin-joined to the base member, and a movable member whose proximal ends are pin-joined to the tips of the pair of link members; an inner guide plate that is integrally attached to the movable member; a swinging plate that is supported to be able to swing at a predetermined angle with respect to the movable member; and an inner guide plate that is attached to the outer link member or the inner link member;
and a spring that provides elasticity so that the pantograph link mechanism, to which the operating cable is fixed at one end, is deformed in a certain direction, and a member that moves relative to the movable member as the pantograph ring mechanism deforms. and a motion conversion mechanism that converts the relative movement of the movable member to the swinging motion of the swinging plate. Examples of the members that move relative to the movable member as the pantograph ring mechanism deforms include the inner link member, the outer link member, and the end of a torsion spring that biases the pantograph link mechanism to deform in one direction. Further, the swing plate may be configured such that a member corresponding to a conventional outer guide plate is swingable relative to a movable member, or may be configured to swing just inside the conventional outer guide plate. It may be configured by a separate member. [Operation] When the chino rests on the outermost largest diameter sprocket, that is, when the movable member is located at the outermost position of its travel stroke, the swing plate will move within its swing range. The distance between the inner guide plate and the swing plate is the same as the distance between the inner guide plate and the outer guide plate in a conventional front derailleur. Carefully spaced and patted. When the pantograph link mechanism deforms in such a way that the movable member moves in parallel from the outermost position of its travel stroke inward, that is, toward the small sprocket as described above, the torsion spring, for example, The relative movement of the ends of is converted by the motion conversion mechanism, and the swing plate gradually swings inward. When the movable member moves to the innermost cutting edge of its travel stroke, the amount of inward rocking of this rocking plate becomes maximum, and at this time, the distance between the inner guide plate and the rocking plate is equal to the width of the chino.
This results in a narrow interval corresponding to 1゛. Conversely, when the pantograph link mechanism deforms so that the movable member moves outward from the state where it is located at the innermost edge of its travel stroke, the swing plate moves from the state where it swings inward to the maximum extent. It gradually swings back to the outside and finally assumes the outermost position of its swing range. That is, in the bicycle front derailleur of the present invention, whereas conventionally the interval between the inner guide plate and the outer guide plate was fixed at a wide interval with a certain margin relative to the width of the chain, it is possible to The distance between the inner guide, door plate, and swing plate is changed when the member is moving toward the outer large-diameter sprocket and when the movable member is moving toward the inner small-diameter sprocket. , when the movable member is located outward, it is wide (and when the movable member is located inward, it is narrowed).

[Effect] As a result, for example, you can replace the chain between the three sprockets: the outer sprocket with the largest diameter, the middle sprocket that is slightly smaller, and the inner sprocket that is much smaller in diameter than the middle sprocket. When replacing the sprocket, the space between the inner guide plate and the swinging plate is narrow, almost the same as the width of the chaino, so it is guided by the inner surface of the inner guide plate and the inner surface of the swinging plate, and is removed from the intermediate sprocket. The chino that has been dropped will definitely fall onto this small inner sprocket without jumping over the inner sprocket. Therefore, the bicycle front derailleur of the present invention can be used not only when changing the chain from a small diameter sprocket to a large diameter sprocket in a bicycle having three or more sprockets including a fairly small diameter inner sprocket, but also when changing the chain from a small diameter sprocket to a large diameter sprocket. Even when changing the chain from a sprocket to a small-diameter sprocket, the chain can be reliably hooked without causing the chain to fall off. Moreover, when the movable member is moving outward, the interval between the inner guide plate and the swing plate is set so that there is a margin for the width of the chain, as in the conventional case. There will be no abnormal noise caused by contact with the inner guide plate or the swing plate, and no unnecessary wear on the plate. [Description of Embodiments] Hereinafter, embodiments of the bicycle front derailleur of the present invention will be specifically described with reference to the drawings. FIG. 1 is a view of the bicycle front derailleur 1 of the present invention viewed from the right side of the bicycle, and FIG. 2 is a view of the bicycle front derailleur 1 viewed from the rear of the seat pipe. As shown in these figures, the front derailleur l is attached to the seat pipe 2 with a clamp band 3. The clamp band 3 is composed of a pair of semi-annular members 3a and 3b that are hinged together so as to be openable and closable.The clamp band 3 holds the seat pipe 2 inside and tightens the open end with a screw 4, so as to clamp the seat vibe 2. Fixed. seat pipe 2
A base member 4 is integrally formed on the right side of the semi-annular member 3a located at the rear of the bicycle. This base member 4 constitutes a part of a pantograph link mechanism 7 for moving a movable member to be described later in parallel to the left and right directions of the bicycle. The upper ends toa and l of the inner link member 10 and the outer link member 11 are attached to the extending pin 8°9, respectively.
la is rotatably supported. Furthermore, the movable member 1 is attached to the lower end portions tab and itb of these link members 10.11.
2 are rotatably connected via support pins 13 and 14, respectively. Each of the pins 8.9, 13.14 is positioned so as to form each vertex of a parallelogram, and thus the base member 4, the inner link member 10, the outer member 1
1 and the movable member 12 constitute a parallelogram pantograph link mechanism 7 that is deformable so that the inner and outer link members 10 and 11 swing relative to the fixed pins 8 and 9. When this pantograph link mechanism 7 deforms, the movable member 1
2 moves parallel to the above along an arc locus centered on 78 or pin 9 while maintaining its directionality constant. In addition, at the upper end of the inner link member 10, there is a rotation range regulating stopper pole l-15 screwed onto the base member 4.
A stopper surface 17 is formed that can come into contact with the movable member 16, thereby regulating the movement stroke of the movable member 12 within a desired range. That is, by adjusting the amount of compression of the stopper poles 1-15, 16, the movement range of the movable member 12 can be adjusted to a desired amount. In a conventional front derailleur, the movable member 1
However, in the front derailleur of the present invention, only the inner guide plate 5 is integrally provided with respect to the movable member 12, and the outer guide plate 5 is provided integrally with the movable member 12. A corresponding member is replaced by the swing plate 6, which is provided so as to be able to swing within a certain range relative to the movable member 12, that is, to be able to swing through a predetermined angle about the pin 14. As shown in FIGS. 1 and 3, the swing plate 6 is always elastically biased outward by a first torsion spring 20 provided so as to surround the pin 14. has been done. Therefore, it assumes this oscillating brake position. At this time, the distance between the inner guide plate 5 and the swing plate 6 is a distance that is slightly larger than the width of the chino, as in the conventional case. Modifications of the pantograph link mechanism 7 include the inner and outer link members 10 that constitute this pantograph link mechanism.
This is done by extending the actuating arm 18 to one of the ends of the actuating arm 11 and pulling the operating cable w1 fixed to the end of the actuating arm 18, thereby swinging the actuating arm 18 or the link member 10.11. Note that this operation cable w1 includes an inner cable W1 and an outer cable W.
Although the inner cable W1 of the operating cable W consisting of two parts is connected to the actuating arm 18, a so-called bare type operating cable without an outer cable may also be used. In this example, in particular, the actuating arm 18
is attached to the outer link member 11 so as to be able to swing slightly relative to the angle. That is, while supporting the outer link member 11 with respect to the base member 4, the operating arm 18
An elongated hole 19 extending in an arcuate direction centered on the pin 9 is provided in the elongated hole 19, and the outer link member 11 and the movable member 12 are inserted into the elongated hole 19.
A pin 14 is inserted through the pin 14 to rotatably connect the two. As a result, the actuating arm 18 can swing relative to the outer link member 11 within a range allowed by the elongated hole 19. Furthermore, in this example, the pantograph link mechanism 7 is
In the following manner, the movable member 12 is elastically biased to the so-called low normal type, that is, so that when the operating force is released, the movable member 12 moves toward the innermost minimum diameter sprocket (low gear). That is, the second torsion spring 21 is fitted into the support pin 13 that rotatably connects the lower end 10b of the inner link member 10 and the movable member 12, and with the second torsion spring 21 in a state where it can be squeezed, One end 21a is hooked on the inside of the pin 8 that rotatably connects the upper end of the inner link member 1O and the base member 4, and the other end 21b is provided on the outside of the protruding shaft 22 provided at the lower end portion of the operating arm 18. It's hooked on. As a result, the second torsion spring 21 substantially urges the pin 8 and the protruding shaft 22 to approach each other in FIG. 12 is biased to move inward. In the present invention, when the pantograph link mechanism 7 deforms, a member that moves relative to the movable member 12,
A motion conversion mechanism 23 is provided which converts the relative movement of the movable member 12 to the swinging motion of the swinging plate 6. When the pantograph link mechanism 7 is deformed, the movable member 12
As a member that moves relative to the inner and outer link members 1
0, 11 and the other end 21b of the second screw spring 21. As can be seen from FIGS. 4 to 6, the movable member 12 is located at the outermost position! @ (Fig. 6) to the state where the movable member 12 is located at the innermost position (Fig. 6).
While the pantograph link mechanism 7 is deformed to the point shown in FIG. Further, when the movable member 12 moves from the innermost position to the outermost position, contrary to the above, the other end 21b of the second screw spring 21 is centered around the dowel pin 13. It is relatively rotated clockwise. In this example, a motion converting mechanism 23 is configured to convert the above-described movement of the end 21b of the second torsion spring 21 into a swinging motion of the swinging plate 6. The motion conversion mechanism 23 is configured such that the second torsion spring 21
The protrusion 2 at the other end 21b is hooked on the protrusion 22
A rotating piece 25 having an input protrusion 24 that bypasses the protrusion 22 and abuts on the side surface that abuts the outer guide plate 2 is rotatably supported by a support pin 14 that supports the outer guide plate 6. Action portion 2 provided in the passage of the upper extending piece of the rotating piece 25
6 is brought into contact with the tip of a stopper screw 28 screwed into a branch piece 27 integrally formed on the outer guide plate 6. Next, the operation of the above embodiment, including the motion conversion mechanism 23, will be explained with reference to FIGS. 4, 5, and 6. FIG. This shows a state where the state has shifted to some extent. At this time, the other end 21b of the second torsion spring 21 is in a state of relative rotation in the clockwise direction, and since the acting part 26 of the rotation piece 25 and the stopper screw 28 are separated, the swing The plate 6 is swung to the outermost position by the action of the first torsion spring 20, and therefore the distance between the inner guide plate 5 and the swiveling plate 6 is a little more than the width of the chino C. This is the widest spacing. When the pulling force of the operating cable W1 is loosened from this state, as shown in FIG. 5, the movable member 12 gradually moves inward, and the other end 21b of the second torsion spring 21
rotates counterclockwise. As a result, the rotating piece 25 rotates clockwise about the pin 14, and its operating portion 26 comes into contact with the stopper screw 28. When the pulling force of the operation cable W1 is further loosened, the sixth
As shown in the figure, first, the operating arm 18 units L/T1
1 st ÷ 1 ＾ Ko wo pot hiroku → to Z lead χ 閤 H go et al AI It 4/ h It is rotated in the direction of arrow A relative to pin 9 with respect to 11, and pin 14 After contacting the inner wall of one end of the elongated hole 19, the actuating arm 18 and the outer link member 11 further rotate in the direction of arrow A as a unit. Along with this behavior of the actuation arm 18, the other end 21b of the second screw spring 21 further rotates counterclockwise, which causes the rotation piece 25 to further rotate clockwise around the pin 14. . This movement of the pivot piece 25 presses the stopper screw 28 of the pivot plate 6, so that the pivot plate 6 is pivoted inward, as shown in FIG. At this time, the interval between the inner guide plate 5 and the swing plate 6 is narrower than the interval shown in FIG.
Therefore, the width of Cheno C, which has been removed from the intermediate sprocket S2, is guided by the narrowed inner surfaces of the inner guide plate 5 and the swing plate 6, and is surely dropped into the inner smallest diameter sprocket S1. It will be done. In this example, as described above, the actuating arm 18 is rotatable relative to the outer link member 11 within the range allowed by the elongated hole 19, so the movable member 12 is rotated as shown in FIG. After shifting the chain C to the smallest diameter sprocket S1 and pulling the operating cable w1 slightly, the shape of the pantograph link mechanism 7 can be changed to the shape shown in Fig. 6 as shown in Fig. 5. While holding the operating arm 1 in the state shown,
8 in the direction of arrow B in FIG. The distance between the swing plate 6 and the swing plate 6 can be increased. By doing this, after the chain C is engaged with the smallest diameter sprocket, contact with the guide plate or the swing plate due to swing of the chain C can be avoided, and unpleasant noises or damage to the guide plate and the swing plate can be avoided. Unnecessary wear can be avoided. The movable member 12 is moved outward, and the Cheno C is moved outward to the large diameter sprocket 32. When changing the hook to S3, the fifth
The operating cable W1 may be further pulled from the state shown in the figure. As described above, in the bicycle front derailleur of the present invention, when the pantograph link mechanism is deformed, the inner and outer link members or the pantograph link mechanism are deformed in one direction with respect to the movable member integrated with the inner guide plate. Note that the ends of the torsion springs that actuate behave relative to the movable member, and the relative movement of these members to the movable member can be controlled by replacing the conventional outer guide plate with respect to the movable member. This is converted into a rocking motion of a rocking plate that can swing. As a result, the swinging member is swung in accordance with the movement of the movable member 12 in the left-right direction, and when the movable member is located at the outermost position, the distance between the inner guide plate and the swinging plate is widened, and on the other hand, When the movable member is located at the innermost position, the distance between the inner guide plate and the swing plate can be reduced. As a result, it becomes possible to reliably perform the operation of changing the chain on the inner, smallest diameter sprocket, which is considerably smaller than the outer, large diameter sprocket. It is not limited. For example, in the embodiment, the actuating arm is made to be able to swing relative to the outer link member by a slight angle, and after replacing the Cheno C on the smallest diameter sprocket, the swing plate can be moved without changing the position of the movable member. Although the structure is configured so that the operating arm can be swung back and the distance between the inner guide plate and the oscillating plate can be widened, the object of the present invention cannot be achieved even if the actuating arm is formed integrally with the outer link member. sell. Further, in the embodiment, one end of a torsion spring for deforming and biasing the pantograph link mechanism is selected as the member that moves relative to the movable member, but the present invention is not limited to this.
Relative movement of the inner link member or the outer link member with respect to the movable member may be converted into movement of the swing plate. Furthermore, in the embodiment, the present invention is applied to a so-called low normal type front derailleur, but a top normal type front derailleur Is Taishun 011 in which the spring biasing direction of the pantograph link mechanism is opposite to the embodiment. Book; ai
tnν6Hess - Furthermore, in the embodiment, instead of the conventional outer guide plate, a plate having the same shape as the conventional outer guide plate and configured to be swingable relative to the movable member is used as the swing plate. However, for example, it is configured by leaving a fixed guide plate with respect to the conventional movable member, and adding a separate rocking plate that can swing relative to the movable member inside this fixed guide plate. Even if
Of course it's good. Furthermore, the motion conversion mechanism converts the movement of the member relative to the movable member into the swinging motion of the swinging plate.
By combining a cam mechanism and a link mechanism, it can be realized in various ways other than the illustrated example.

[Brief explanation of the drawing]

The first is a view of one embodiment of the front derailleur of the present invention viewed from the right side of the bicycle, and the second is the 1y! 3 is a schematic view of the above example as seen from the front side of the seat pipe to explain the assembly structure of the first torsion spring. , Figures 5 and 6 are
FIG. 3 is an explanatory diagram of the operation of the above example.

Claims (1)

[Claims] (1) A pantograph link mechanism consisting of a base member, an outer link member and an inner link member whose proximal ends are pin-joined to the base member, and a movable member whose tips are pin-joined to the tips of the pair of link members, and the movable member. an inner guide plate integrally attached to the movable member, a swinging plate supported to be able to swing at a predetermined angle with respect to the movable member, and an operating cable attached to one end of the inner guide plate attached to the outer link member or the inner link member. A fixed operating arm, a spring that provides elasticity so that the pantograph link mechanism deforms in a certain direction, and a member that moves relative to the movable member as the pantograph ring mechanism deforms. A front derailleur for a bicycle, comprising: a motion conversion mechanism that converts motion into rocking of the rocking plate.