JPS6241913B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an external bicycle transmission, and more particularly, the present invention relates to an external bicycle transmission, and more particularly, it is possible to assemble the bicycle externally, and the end of the operating wire on the transmission side is connected to the link mechanism inside the link mechanism. The present invention relates to an external bicycle transmission that is fixed to constituent members and can minimize external protrusions of a link mechanism.

Conventional external bicycle transmissions of this type, in particular,
As shown in Japanese Utility Model Publication No. 57-7592, the rear transmission is equipped with a guide roller for guiding the chain in the direction of the hub axis and a tension roller for applying tension to the chain. The frame is configured to be able to move in the direction of the hub axis while maintaining a parallel relationship with the freewheel sprocket using a so-called parallelogram pantograph link mechanism (hereinafter referred to simply as the link mechanism). .

This link mechanism includes a base member attached to the rear end plate of the bicycle, a pair of link members extending parallel to the base member and swingable with respect to the base member, and a tip portion of the link member that is attached to the link member. It consists of a movable member that is swingably attached, and the diagonal of the parallelogram formed by the base member, a pair of link members, and the movable member is controlled by using an operating wire with one end connected to an operating lever, etc. It is configured to be deformed by changing its length.

By the way, in such a conventional rear transmission, the connecting portion of the link member to the base member and the connecting portion of the movable member to the link member form a link member receiving portion having a substantially U-shaped cross section on the base member and the movable member. However, it has generally been constructed by rotatably supporting support pins attached to both ends of the link member so as to span between the upper and lower support pieces of the receiving portion. To assemble this connecting portion, it is necessary to align the holes drilled in the support piece with the holes drilled in the link member, and insert the support pin into these holes so as to communicate with these holes. However, as mentioned above, the process of aligning the holes of the support piece with the holes of the link member and inserting the support pin into these holes in a driving manner is not suitable for automation, and therefore, this process is At present, it relies on manual labor.

In addition, in the configuration of a general link mechanism in a conventional external bicycle transmission as shown in the above-mentioned publication, the end of the operating wire connects the link mechanism as shown in FIG. It is necessary to attach a wire fixing member to the lower part of the constituent members by protruding it, and therefore,
There was also a risk that this wire attachment part could injure the feet of passengers and the fingers and fingers of the person adjusting the transmission.

The present invention solves the above-mentioned problems with conventional bicycle external transmissions, and allows for automatic assembly.
In addition, the end of the operating wire on the transmission side is fixed to the members that make up the link mechanism inside the link mechanism, making it possible to minimize the number of protrusions on the outside of the link mechanism. The purpose is to provide

In order to achieve such an objective, the present invention:
The following technical measures have been taken for the structure of the link mechanism in the external bicycle transmission. That is,
A pair of parallel support shafts is provided by fixing one end of the shaft to the base member, a pair of parallel support shafts are provided by fixing one end of the support shaft to the moving member, and a pair of parallel support shafts are provided by fixing one end of the support shaft to the movable member. A shaft support hole capable of rotatably supporting each of the support shafts is provided, and the support shaft on the base member side and the support shaft on the movable member side,
The base member and the movable member are assembled by fitting the shaft support holes at both ends of a link member located in a spanning manner between the base member and the movable member.

In this way, the following effects can be expected. That is, the step of fitting the shaft support hole at one end of the link member into the support shaft provided on the base member, and the step of fitting the shaft support hole at the other end of the link member into the support shaft provided on the movable member are as follows. , are all simple steps, so these steps can be easily automated. As a result, it becomes possible to automate the assembly of a bicycle external transmission, especially the link mechanism, which was extremely difficult to automate in terms of cost or technology with conventional structures. Furthermore, among the four members constituting the link member, the base member and the movable member do not need to be formed into a substantially U-shaped cross section as in the past. It is easy to create because all you need to do is to Furthermore, since it is no longer necessary to form the base member and the movable member into a substantially U-shaped cross section, the base member and the movable member, which have a U-shaped cross section, can close the gap between both ends of the pair of link members. Since both ends of the pair of link members are open, the end of the operating wire is inserted into the link mechanism from this open part, that is, between the pair of parallel link members. This can be introduced between the link members and fixed to the members constituting the link member. In this case, the conventional problem that the operating wire fastening part protrudes from the lower part of the link mechanism is solved.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

As is clear from FIGS. 1 and 2, this embodiment shows an example in which the present invention is applied to a bicycle rear transmission (hereinafter referred to as a transmission).

The transmission 1 is attached to the bicycle frame 6 by screwing a mounting portion 2a extending from the upper part of the base member 2 into a screw hole 5 provided in a rear end plate 4. The base member 2 is also rotatable around the screw 3, and by turning the adjusting screw 7,
The entire transmission 1 is rotated around the screw 3 in the direction of the arrow in Figure 1, and the transmission 1 can be adjusted to the most appropriate position by taking into consideration the distance to the multi-stage sprocket S and the length of the chain C. It's getting old.

As shown in FIG. 3, a flat surface 8 is formed on the lower surface of the base member 2, from which a pair of support shafts 9a and 9b are protruded downward in parallel. . The support shafts 9a, 9b may have their proximal ends driven or screwed into holes previously provided in the flat surface 8, or may be integrally formed. On the other hand, the upper surface of the moving member 10 also has a flat surface 11.
is formed, and a pair of support shafts 12a, 12b are formed in parallel to project upward from this.
The support shafts 12a and 12b may be formed in the same manner as the support shaft 9.

The support shafts 9a, 9b on the base member side and the support shafts 12a, 12b on the movable member side have shaft support holes 13a, 13b, 14a provided at both ends of a pair of link members 13, 14 facing in parallel. 14b is fitted. These shaft support holes 13a, 13b, 14
The inner diameters of a and 14b are the same as those of the support shafts 9a and 9, respectively.
b, 12a, 12b is determined to be rotatably supported. Thus, the distance between the support shafts 9a and 9b is constant, the distance between the support shafts 12a and 12b is constant, and the distance between the support shafts 9a and 12a and between the support shafts 9b and 12b is constant. are connected by the outer link member 13 and inner link member 14, each having a certain length, so these base member 2, outer link member 13, inner link member 14 and moving member 10 are A parallelogram pantograph link mechanism is formed with the support shafts 9a, 9b, 12a, and 12b as vertices.

In this embodiment, the support shafts 9a, 9b, 1
After the inner and outer link members 13 and 14 are fitted into the shafts 9a and 12b, stop plates 15 and 16 are attached to prevent the inner and outer link members 13 and 14 from slipping out.
It is also possible to simply fit a retaining ring to the tips of b, 12a, and 12b.

In order to deform the link mechanism, for example, an external force may be applied to change the length of the diagonal of the parallelogram. In this embodiment, the distance between the base member side end of the inner link member 14 and the moving member side end of the outer link member 13 is expanded and contracted by using a double wire consisting of an inner wire wa and an outer wire wb. I try to transform it by using it. i.e. outer wire wb
The end of the inner wire wa is fixed to the end of the inner link member 14 on the base member side, and the end of the inner wire wa is fixed to the end of the outer link member 13 on the movable member side. By applying axial movement, the length of the diagonal of the parallelogram is changed.

As is clear from FIGS. 4 and 5, at the end of the inner link member 14 on the base member side, there is a receiving hole 17 that can receive the end of the outer wire wb, and an inner wire insertion hole 18 that is continuous with the receiving hole 17. An outer wire attachment part 19 is formed integrally with the outer link member 13, and an inner wire attachment part 20 is formed at the end of the outer link member 13 on the movable member side. As clearly shown in FIGS. 4 and 5, this inner wire fastening part 20 has an inner wire insertion hole 21 formed in a thick part formed in a part of the outer link member 13. A pressing member 23 having a hole 22 for holding the inner wire is provided in the middle part, and the pressing member 23 is screwed into the screw means 24.
By forcibly moving the wire wa in the lateral direction with respect to the extending direction of the wire wa, a part of the inner wire wa is pressed and fixed against the inner wall of the inner wire insertion hole 21. In addition, the inner wire insertion hole 21
The entrance of the inner wire wa has an enlarged diameter in a cone shape, thereby making it easy to introduce the end of the inner wire wa into the through hole 21, thereby facilitating the work of attaching the end of the inner wire.

When using a so-called push-pull type wire that can also transmit the pushing force of the inner wire wa as the operating wire for deforming the link mechanism 1, the link mechanism 1 is deformed and biased in one direction. There is no particular need for a spring for this, but
As in this example, when using a so-called pull-type wire, which is made by twisting thin wires and can only transmit force in the tensile direction, as the inner wire,
As shown in FIGS. 4 and 5, the spring 2
5, it is necessary to bias this link mechanism so that it deforms in one direction. In this embodiment, a torsion spring 25 is provided to support the inner link member 14 and the movable member 10 so that the link mechanism 1 is always elastically deformed in the direction of arrow P in FIG. It is inserted into the shaft 12b.

Further, in this embodiment, means for defining and adjusting the range of deformation of the link mechanism is provided. That is, the stop plate 15 and the moving member 10 are provided with a stopper surface 26, respectively.
27 and the outer link member 14
Adjustment screws 28 and 2 cooperate with the stopper surfaces 26 and 27 to define the swinging end of the link mechanism 1.
9 is screwed in. As shown in FIGS. 4 and 5, when the movable member 10 is moving to the outermost side, that is, in the direction of arrow A in FIG. 1 is defined, and when the movable member 10 is moving to the innermost side, that is, in the direction of arrow B in FIG. A deformed end is defined.

The movable member 10 has a hanging frame 32 that is especially configured in the rear transmission as a chain guide that presses the chain C in the lateral direction, that is, a hanging frame 32 that extends around an axis (not shown) parallel to the hub shaft (not shown). A replacement frame 32 is attached which is rotatable and includes a guide roller 30 for guiding the chain C in the hub axis direction and a tension roller 31 for applying tension to the chain C.

The bicycle external transmission according to the present invention constructed as described above, particularly its link mechanism, can be easily assembled as follows.

A pair of support shafts 9a, 9 protruding from the base member 2
After fitting the shaft support holes 13a and 14a of the outer link member 13 and inner link member 14 into the shaft 9,
The retaining plate 15 and the retaining ring 33 are fitted into the tips of a and 9b, while the outer link member 13 and the inner link member 1
A pair of support shafts 12a, 12 protruding from the moving member 10 in the shaft support holes 13b and 14b on the moving member side of No.4.
b, respectively, and then this support shaft 12a,
It is sufficient to simply fit the retaining plate 16 and the retaining ring 34 to the tip of the retaining member 12b.

As described above, in the present invention, when assembling a link mechanism in an external bicycle transmission, for example, unlike in a link mechanism of a conventional structure, the subtleties of aligning two holes and the holes that are aligned in this way are avoided. Since a complicated process that requires a large amount of force, such as inserting a pin in a driving manner, is not required, it is now possible for the first time to automatically assemble an external bicycle transmission, which was previously considered impossible.

Furthermore, as best seen in FIGS. 4 and 5, the link mechanism of the bicycle external transmission of the present invention does not have a member that closes the gap between both ends of a pair of opposing link members. The operating wire can be introduced through the gap and its end can be fixed to the members constituting the link mechanism in the internal space of the link mechanism, thereby minimizing the number of members protruding to the outside of the link mechanism. be able to.

[Brief explanation of the drawing]

The drawings show an embodiment of the bicycle external transmission according to the present invention, and FIG. 1 is a front view, FIG. 2 is a side view, FIG. 3 is a front view showing the components in an exploded state, FIG. FIG. 5 is a sectional view for explaining the operation. 1...Link mechanism, 2...Base member, 9a, 9b
... Support shaft (of the base member), 10... Moving member, 12
a, 12b, ... (moving member) spindle, 13, 14
...link member.

Claims (1)

[Scope of Claims] 1. A base member attached to a bicycle frame, a pair of link members extending parallel to the base member and swingable with respect to the base member, and a base member attached to each link member at the distal end of the pair of link members. In an external bicycle transmission comprising a parallelogram pantograph link mechanism consisting of a moving member that is swingably connected to the moving member, and a chain guide that presses the chain in the lateral direction attached to the moving member. The parallelogram pantograph link mechanism is provided with a pair of parallel support shafts fixed to the base member at one end, and a pair of parallel support shafts fixed to the movable member at one end. , a shaft support hole capable of rotatably supporting each of the support shafts is provided at both ends of the pair of link members, and the support shaft of the base member and the support shaft of the movable member span between the base member and the movable member. An external bicycle transmission, characterized in that the bicycle external transmission is configured to be assembled by fitting into the shaft support holes at both ends of the pair of link members positioned in a shape.