JPS6117716B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an external bicycle transmission, and more particularly, to a bicycle rear transmission for changing a chain to a selected gear of a freewheel consisting of three to eight gears. The present invention includes an improvement of a bicycle front transmission (front derailleur) for changing the chain to a selected one of two to four multi-stage gears.

Conventionally, this type of external bicycle transmission has been the first
As shown in FIG. 1, most of the systems are constructed so that the tensioner moves in the hub axis direction so as to be parallel to each gear of the multi-stage freewheel using a so-called parallelogram pantograph link mechanism. That is, a pair of opposing parallel links b1 and b2 are rotatably supported on a fixed member a that is integrally attached to the fork end of the bicycle frame, and the fixed member a is attached to the distal ends of the parallel links b1 and b2. Pivotally supporting a movable member c facing member a,
A tensioner e consisting of a guide pulley d and a tension pulley (not shown) is rotatably supported on the movable member c, and is formed by a fixed member a, a pair of links b1 and b2, and a movable member c. By changing the length of the diagonal line of the parallelogram using a traction means using a wire f, the moving member c or tensioner e was moved while remaining parallel to the multistage gear (see the chain line in Fig. 11). ). In the parallelogram link mechanism described above, a coil spring (not shown) is fitted onto one of the four pivot pins so as to bias the links b1 and b2 in one direction. When the wire f is pulled, the movable member c moves in parallel against the elasticity of the coil spring, and when the wire c is loosened, the movable member c returns to its original position due to the elasticity of the coil spring.

However, such conventional bicycle external transmissions include various problems listed below.

That is, the above-described parallelogram pantograph link mechanism moves the moving member c in parallel by changing the diagonal length of the parallelogram, but in order to perform such a deformation operation by wire operation, this The end fastening part h of the outer wire g is attached near one end of the diagonal of the parallelogram (in the example shown in FIG. 11, the end of the link b1 on the fixed member a side), and the end fastening part h of the outer wire g is attached near the other end of the diagonal (the In the example shown in the figure, an end fastening part k of the inner wire j is provided in the vicinity of the pivot pin for the link b2 of the movable member c, and the inner wire j and the outer wire g are slid relative to each other in the axial direction. The only way is to increase or reduce the distance between the end fastening part h and the inner wire end fastening part k. Therefore, a double wire consisting of an inner wire and an outer wire g inserted into the inner wire must be used as the wire f, and in this case, the relative sliding of the inner wire j and the outer wire g has a considerably large sliding frictional resistance. Therefore, it is necessary to use a coil spring with considerably high spring rigidity to be installed inside the transmission and to bias the parallelogram pantograph link mechanism to rotate in one direction.
This means that a considerably large operating force is required to pull and operate the inner wire j using a control lever or the like.

In addition, in the deformation operation method using double wires in the parallelogram pantograph link mechanism as described above, as detailed in FIG. ) changes, the outer wire fastening part h has to be provided near the fixed member a whose position does not change. For example, contrary to FIG. It is practically impossible to provide the fastening parts k in the vicinity of the fixing member a so as to pull the inner wire j toward the front of the bicycle. Therefore, the outer wire g extending rearward from the chain stay (not shown) of the bicycle frame is curved in a U-shape near the transmission, and the end is moved toward the front of the bicycle, that is, in the parallelogram pantograph ring mechanism. It was fixed near the fixing member a toward the member c side. For this reason, the sliding resistance between the inner wire j and the outer wire g in the U-shaped curved portion is even greater, and this is one of the reasons why the speed change operation becomes extremely difficult.

Furthermore, in the conventional configuration in which the pantograph ring mechanism is deformed and its movable members are moved in parallel, all the members that make up this pantograph link mechanism are exposed to the outside, and each member and the connection between the members are exposed. It was impossible to prevent rust from forming or dirt from adhering to the transmission, and this was a major cause of deteriorating the performance of the transmission.

The purpose of the present invention is to provide a completely new type of external transmission that solves all the problems of the conventional external transmission for bicycles. A bicycle configured to connect a movable member to which a tensioner or a chain guide plate is attached via a control mechanism, and to move the tensioner or chain guide plate in parallel to change the chain to a desired sprocket. In the external transmission, the control mechanism includes a fixed shaft integrally provided on the base body, and a fixed shaft provided integrally on the movable member and parallel to the fixed shaft at a predetermined interval. a box-shaped rotating member having a substantially sealed space inside and rotatably supported such that the fixed shaft and the moving shaft respectively protrude into the internal space from the outside; , a regulating means for preventing the movable shaft from rotating even if the rotatable member rotates about the fixed shaft within an internal space of the rotary member; a spring built into the rotating member so as to bias the rotating member; The present invention is characterized in that an arcuate wire take-up reel is provided, and the free end of the operating wire that runs along the wire take-up reel is fixed at the end of the reel.

When the box-shaped rotating member that accommodates the fixed shaft is rotated, the movable member at the other end of the rotating member is caused to translate in parallel without rotating. As a result, the tensioner attached to the moving member moves in parallel in the axial direction of the multi-stage freewheel, and the chain is replaced with a desired sprocket.

In addition, in order to operate the transmission, it is only necessary to rotate the rotating member, so there is no need to use double wires, and the bare wire is fixed to the part of the rotating member that surrounds the fixed shaft. The traction force of the wire can be easily converted into rotation of the rotating member by simply using the above-described method. Moreover, in the present invention, an arc-shaped wire take-up reel having a center substantially the same as the axis of the fixed shaft is provided on the outer periphery of the rotating member surrounding the fixed shaft, and the wire is placed along this take-up reel and then reeled. Since it is fixed to the outer surface of the movable member, the wire does not swing as the rotary member rotates, and the wire can be routed in one direction, the most efficient direction. Further, since the rotating member rotates in proportion to the amount of pulling of the wire, the operating feeling is improved and the lever rotation angle can be easily set when a click mechanism is provided on the operating lever side.

Furthermore, since the functional parts that make up the control mechanism are hermetically housed inside the rotating member, the performance of the control mechanism will not deteriorate due to rainwater, mud, or dust entering from the outside.

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

1 to 8 show an example in which the present invention is applied to a rear transmission.

In FIGS. 1 and 2, 1 is a base for attaching an external transmission to the back fork end 2 of a bicycle frame, 12 is a rotating member, and 4 is a moving member, and this moving member 4 includes a guide pulley. A tensioner 7 is rotatably supported by a tensioner 5 and a tension pulley 6, respectively. The chain c travels while meshing with the tension pulley 6, the guide pulley 5, and the selected sprocket S of the freewheel F in sequence, as shown by the chain line in FIG. The tensioner 7 is elastically biased in the clockwise direction in FIG. 1 about the pivot shaft 8 of the guide pulley 5, and applies a constant tension to the chain c. In the illustrated example, this biasing method is carried out by interposing a spiral spring 9 inside the moving member 4.

As is clear from FIGS. 1 and 2, in the bicycle external transmission according to the present invention, the parallelogram in the conventional example is used as a control mechanism for moving the moving member 4 or the tensioner 7 in parallel in the hub axis direction. No component corresponding to the pantograph link mechanism is exposed to the outside. This can only be achieved by linking the base body 1 and the moving member 4 with a completely new control mechanism, which will be explained below.

That is, as shown in FIGS. 3 and 4,
A fixed shaft 10 is provided projecting below the base 1, and a moving shaft 11 is provided projecting above the movable member 4, and these two shafts 10, 11 are kept at a constant interval and are connected to each other. 11 are linked together by a substantially sealed box-shaped rotating member 12 that rotatably supports each of them, and even if the rotating member 12 rotates around the fixed shaft 10 inside this rotating member 12, the movement will not occur. A regulating means M is provided to prevent the shaft 11 from rotating. Various means M can be considered, but for example, as shown in the illustrated example, the fixed shaft 10 and the movable shaft 11 are connected by a connecting rod 13 having the same length as the distance between the two shafts. 1
It is simplest if they are substantially connected at two points equidistant from the axes 0 and 11, respectively.

In this example, for convenience of assembly, the rotating member 12 is composed of a bottomed box body 12a having a substantially rectangular cross section and a lid body 12b capable of closing the bottom opening 14 of the box body 12a. A shaft support hole 16 for rotatably supporting the base 10a of the fixed shaft 10 is provided at one end of the ceiling 15 of the box body 12a, and a shaft support hole 16 for rotatably supporting the base 10a of the fixed shaft 10 is provided at the other end.
A shaft support hole 1 rotatably supports the tip end 11b of 1.
7 are drilled respectively. A screw hole 19 into which a bolt 18 for fixing the lid body 12b is screwed is bored at the shaft end of the fixed shaft 10, and a screw hole 19 is formed in the shaft end portion to lock one end portion 13a of the connecting rod 13. A deformed end 21 is formed for non-rotatably fitting the first crank plate 20 onto the fixed shaft 10.

On the other hand, the moving shaft 11 to be provided protruding above the moving member 4 is provided in two pieces for convenience of assembly.
The second moving shaft 11b is connected to the first moving shaft 11a provided in the first moving shaft 11a by screw means.
At the end of the first moving shaft 11a, there is a second moving shaft 11b.
A screw hole 22a into which the screw shaft portion 22 provided in the connecting rod 13 is screwed is bored, and the other end portion 1 of the connecting rod 13
2nd crank plate 23 for engaging 3b
A deformed end 24 is formed which is to be fitted non-rotatably to the first moving shaft 11a. Note that the second moving axis 1
1b protrudes outward from the shaft support hole 17 formed in the rotating member 12 when assembled, and a retaining ring is engaged with this protrusion, or a thin ring 24a is fitted into this protrusion. The rear protruding shaft portion is caulked to prevent the moving shaft 11 from slipping out.

The first crank plate 20 that should be fitted integrally with the fixed shaft 10 and the second crank plate 23 that should be fitted integrally with the moving shaft 11 each have a through hole having the same shape as the irregularly shaped ends 21 and 24. 2
5 and 26, and has engagement holes 27 and 28 in which both ends 13a and 13b of the connecting rod 13 can be engaged, respectively. This engagement hole 2
7 and 28 are opened at positions equidistant from the axes of the fixed shaft 10 and the movable shaft 11, respectively. Furthermore, the first and second crank plates 20,
Contact pieces 31 and 32 are provided on the upper surface near the fan-shaped outer periphery of 23 to cooperate with stopper bolts 29 and 30 provided on the rotation member 12 to restrict the rotation range of the rotation member 12 to a predetermined range. Each one is protruded.

The connecting rod 13 has both ends of a straight wire rod
By bending by .degree., upward shaft ends 13a and 13b are formed which can be engaged with the engagement holes 27 and 28 of the first and second crank plates 20 and 23, respectively. Note that the distance between the upward shaft ends 13a and 13b is determined to be the same as the distance between the fixed shaft 10 and the movable shaft 11. The lid body 12b has through holes 34 and 35 formed in positions facing the two shaft support holes 16 and 17 formed in the box body 12a.

To assemble the above-mentioned parts, the fixed shaft 10 is inserted through the shaft support hole 16 of the rotating member 12a, and the coil spring 33 for biasing the rotating member 12 in one direction is fitted onto the shaft 10. while fitting the first crank plate 20 to the irregularly shaped end 21, and in this state, the one end 13a of the connecting rod 13 is engaged with the locking hole 27 of the first crank plate 20, and the other end 1
3b is engaged with the locking hole 28 of the second crank plate 23, and the second crank plate 23 is fitted to the deformed end 24 of the first moving shaft 11a inserted through the through hole 35 of the lid 12b. At the same time, the lid 12b is fitted into the lower opening 14 of the box 12a, and then the bolt 18 is inserted into the through hole 34 of the lid 12b.
It is inserted through the shaft and screwed into the screw hole 19 at the end of the fixed shaft 10. Furthermore, the second moving shaft 11b is inserted through the upper shaft support hole 17 of the box body 12a, and the threaded shaft portion 22 thereof is inserted into the threaded hole 2 of the eleventh moving shaft 11a, which has been assembled in advance.
Screw into 2a. Note that at this time, the second moving axis 11
If the ring 24 is fixed to the upper end of b, and then the second moving shaft 11b is screwed, the second moving shaft 11
When b is screwed on, the lower surface of the ring 24 is exposed to the box body 12.
This is convenient because the assembly is completed by being pressed against the upper surface of the a. Note that one end 3 of the coil spring 33
3a is locked to the first crank plate 20, and the other end 33b is brought into contact with the inner wall of the rotating member 12 in a slightly constricted state. Further, the above assembly order is only an example, and it goes without saying that there are various other assembly methods.

Next, a fastening part 37 configured as follows is provided for fastening one end of the operating wire W to a suitable part of the box body 12a of the rotating member 12. That is, a wire take-up reel 36 extending in an arc shape centered on the axis of the fixed shaft 10 is formed on the upper peripheral wall of the box body 12a on the side of the fixed shaft 10, and at the end of the wire take-up reel 36, A fixing means 38 for fixing the free end of the wire W is provided. As the fixing means 38, for example, the box body 12
A tightening bolt 40a is screwed together with a tightening washer 40 into a screw hole 39 provided in a, and the wire W is clamped and fixed between the tightening washer 40 and the outer surface of the box body 12a. I can do it.

The free end of the wire W is suspended along the take-up reel 36 and then fixed to the fixing means 38, and the proximal end is connected to a speed change operation lever D fixed to an appropriate part of the bicycle frame 41. Ru. As shown in detail in FIG. 5, the rotating member 12 is always urged to rotate in the direction of arrow T in FIG. is rotated in the direction of arrow R in FIG.
When pulled in the direction of arrow r in the figure, the rotating member 12 moves to the seventh position.
While rotating in the direction of arrow L in the figure, when the lever D is rotated in the direction of arrow F in Figure 1 to loosen the traction force on the wire W, the wire W moves in the direction of arrow f in Figure 8, and the rotating member 12 is rotated back in the direction of arrow L in FIG. 8 with the stored force of the coil spring 33. At this time, the wire W is pulled while being suspended by the arc-shaped reel 36 having the same center as the axis of the fixed shaft 10, so that the amount of rotation of the rotating member 12 can be obtained in proportion to the amount of pulling of the wire W. Moreover, as shown in FIGS. 7 and 8, there is no shaking of the wire as the wire is pulled.

Moreover, at this time, the fixed shaft 10 and the moving shaft 11 are
Since the fixed shaft 10 and the movable shaft 11 are connected by the means M, the fixed shaft 10 and the movable shaft 11 are separated by a certain distance from both shafts 10 and 11 by a connecting rod 13 having a length equal to the distance between the shafts 10 and 11, respectively. Since they are connected at points, even if the rotating member 12 rotates around the fixed axis 10, the movable member 11 moves in an arcuate trajectory around the fixed axis, but does not rotate (see Figure 5). ). In this way, the movable member 4 or the tensioner 7, which is integrally connected to the movable shaft 11, is always connected to each sprocket S1, S2 of the freewheel F.
It will move in the hub axis direction while maintaining parallel to... FIG. 6 is a diagram schematically showing the operation of the means M.

Furthermore, in the above embodiment, as shown in FIGS. 7 and 8, the contact piece 31 provided on the first crank plate 20, the low side stopper bolt 29 provided on the rotating member 12, and the second The abutting piece 32 provided on the crank plate 23 and the top side stopper bolt 30 provided on the rotating member 12 cooperate with each other to restrict the rotatable range of the rotating member 12. Therefore, by adjusting the amount of screwing of the stopper bolts 29, 30, it is possible to adjust the rotation range of the rotating member 12 to a desired amount.

9 and 10 show an example in which the present invention is applied to a bicycle front transmission.

That is, a fixed shaft 110 is integrally provided on a base body 101 fixed to a seat pipe H of a bicycle frame by a tightening band I, and a movable member 10 is integrally provided with a chain guide plate 107.
4 is provided with a moving shaft 111, and these fixed shafts 110 and moving shafts 111 are linked using a box-shaped rotating member 112 having a substantially sealed space inside, as in the embodiment related to the rear transmission described above. be. By doing so, when the operating force transmission wire W whose end is fixed to the fixing part provided with a predetermined reel in the rotating member 112 is pulled or relaxed, the rotating member 112 is fixed to the fixing part of the rotating member 112. While rotating around the shaft 110, the moving member 104 or the chain guide plate 107 moves left and right while remaining parallel to the chain sprocket S.

Of course, the scope of the invention is not limited to the embodiments described above. For example, the coil spring 33 can be installed so as to urge the rotating member 12 to rotate in the direction L in FIG. 5, and the coil spring 33 can also be installed on the moving shaft 11 side. .

Further, as the regulating means M for preventing the moving shaft 11 from rotating, in addition to connecting the fixed shaft 10 and the moving shaft 11 by a predetermined connecting rod 13 as described in the above embodiment, for example,
Gears (not shown) having the same number of teeth are formed on the outer peripheries of the fixed shaft 10 and the moving shaft 11, respectively, and an intermediate gear (not shown) that meshes with the two gears is formed at an intermediate position between the fixed shaft 10 and the moving shaft 11. ) may be constructed by rotatably supporting the shaft. In addition, as another example, an endless chain (not shown) may be suspended around the two gears. As another example, the fixed shaft 10 and the movable shaft 11 may each be formed with winding drums having the same diameter, and an endless wire (not shown) or an endless belt (not shown) may be suspended around these. .

As described above, in the bicycle external transmission according to the present invention, by pulling the wire fixed to the rotating member and rotating the rotating member, the movable member to which the tensioner is attached can be easily translated in parallel. can be done. In addition, since the wire W is wound and fixed on a reel having the same center as the rotation center on the outer surface of the rotation member, the wire W is always pulled at a point a certain distance from the rotation center. be able to. As a result, the wire is not pulled and swayed by the towing body, and the wire can be routed in the most efficient and constant direction. In addition, for the same reason, the amount of rotation of the rotation member proportional to the amount of wire pulling can be obtained, which improves the feeling of shifting operation, and reduces the lever rotation angle when a click mechanism is installed on the operation lever side. Setting is easy.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a bicycle external transmission, which is an embodiment of the present invention, attached to a bicycle frame, Fig. 2 is a front view of Fig. 1, and Fig. 3 shows the internal mechanism of the main parts. 4 is a perspective view showing the main parts in an exploded state, and FIG. 5 is a cross-sectional view shown in FIG.
A sectional view taken along line A; FIGS. 6, 7, and 8 are action explanatory diagrams; and FIG. 9 is a plan view showing a bicycle front derailleur according to another embodiment of the present invention attached to a bicycle frame. , Figure 10 is a side view of Figure 9, and Figure 11 is a side view of Figure 9.
The figure is a plan view showing the main structure of a conventional external transmission. 1... Base body, 4... Moving member, 7... Tensioner,
10... Fixed axis, 11... Moving axis, 12... Rotating member,
36...Wire winding reel, 37...Wire fastening part, 107...Chain guide plate, M...Restricting means, W...Wire.

Claims (1)

[Scope of Claims] 1. A movable member to which a tensioner having a guide pulley and a tension pulley or a chain guide plate is attached is connected to a base body attached to a bicycle body via a control mechanism, and the tensioner Alternatively, the bicycle external transmission is configured to move the chain guide plate in parallel to change the chain to a desired sprocket, and the control mechanism includes a fixed shaft integrally provided on the base body, and a fixed shaft provided integrally with the base body; provided integrally with the moving member,
and a movable shaft arranged parallel to the fixed axis at a predetermined interval, and a substantially sealed space inside, and the fixed shaft and the movable shaft each protrude into the internal space from the outside. A box-shaped rotating member that is rotatably supported, and the moving shaft is prevented from rotating even if the rotating member rotates about the fixed axis within an internal space of the rotating member. a regulating means; and a spring built into the rotating member so as to bias the rotating member in one direction around the fixed axis; An arc-shaped wire take-up reel centered approximately on the axis of the fixed shaft is provided in the surrounding area, and the free end of the operating wire that runs along the wire take-up reel is fixed at the end of the reel. Features: Bicycle external derailleur. 2. The regulating means connects a connecting rod having a length equivalent to the distance between the fixed shaft and the movable shaft to each of the fixed shaft and the movable shaft at positions equidistant from the axes of both axes. An external bicycle transmission according to claim 1, which is constructed by: 3. The regulating means includes sprockets having the same number of teeth on each of the fixed shaft and the movable shaft, and an intermediate sprocket that is rotatably engaged with the sprockets formed on both shafts at the same time. An external bicycle transmission according to claim 1, which is constructed by supporting the bicycle. 4. The bicycle according to claim 1, wherein the regulating means is constructed by providing sprockets having the same number of teeth on the fixed shaft and the movable shaft, and by suspending an endless chain around both sprockets. External transmission. 5. Claim 1, wherein the regulating means is constituted by integrally forming winding drums having the same diameter on the fixed shaft and the moving shaft, respectively, and by suspending an endless belt around both winding drums. External bicycle transmission described in . 6. The regulating means according to claim 1, wherein wire reels having the same diameter are formed on the fixed shaft and the moving shaft, and both wire reels are constructed by suspending an endless wire. Exterior derailleur for bicycles.