JPS6226957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bicycle derailleur, more specifically, a support member is supported on a fixed member, and a movable member is connected to the support member via two link members in the axial direction of a multi-stage sprocket mounted on the bicycle. The present invention relates to a bicycle derailleur which is supported in a freely movable manner and has a chain guide body attached to the movable member to guide the chain to one of the multi-stage sprockets.

In general, bicycles such as cycling vehicles are equipped with a multi-stage sprocket, in which a plurality of sprockets of different diameters are arranged at predetermined intervals, freely rotatable on a hub shaft supported on the bicycle frame, and are fixed to the bicycle frame near the multi-stage sprocket. By attaching the derailleur through a member and moving the movable member of the derailleur in the axial direction of the multi-stage sprocket by pulling the operating wire, the chain can be hooked to any sprocket of the multi-stage sprocket via the chain guide. I'm trying to change gears by changing it.

The movable member and chain guide in the derailleur are moved in the axial direction of the sprocket by swinging the link member relative to the fixed member, and the movement is performed by swinging the link member relative to the fixed member. The chain is changed by moving the sprocket in the axial direction by the stroke amount.

However, as shown in FIG. 5, even if the swing angle θ ₁ to _{θ 4} of the link member with respect to the fixed member is constant, the stroke amount l ₁ to _{l 4} of the movable member and the chain guide body is The stroke amount l ₁ to _{l 4} varies depending on the swing position.
In order to make the angles constant according to the spacing between the sprockets of the multi-stage sprocket, it is necessary to set the swing angles θ ₁ to _{θ 4} of the link members in advance according to the swing positions thereof.

However, in the derailleur, its fixing member is fixed along the outer surface of the frame, in particular, the fork end, whereas the sprocket is supported by a hub shaft fixed to the fork end, and is connected to the fork end. Since the positions are not constant, the positions of the chain guide and the sprocket often deviate when the derailleur is fixed to the fork end.

Therefore, in order to eliminate this deviation, two adjustment screws are generally used to regulate the high speed side position and low speed side position of the chain guide, in other words, adjustment screws are used to adjust the swing range of the link member. The swing range of the link member is adjusted to match the high-speed side position or low-speed side position of the chain guide with the high-speed sprocket or low-speed sprocket in the multi-stage sprocket.

However, when the swing range of the link member is adjusted,
The stroke amount l ₁ to _{l 4} of the chain guide relative to the swing angles θ ₁ to _{θ 4} also changes, and when the chain is replaced by the chain guide, the position relative to the sprocket other than the high speed sprocket or the low speed sprocket changes. This will result in misalignment. When adjusting the swing range of the link member, the swing angle of the link member may be adjusted in accordance with this adjustment, but if the derailleur is equipped with a positioning mechanism, the link member It is not possible to adjust the swing angle of the link member, and if the lever is provided with a scale or a positioning mechanism, adjusting the swing angle of the link member will result in This changes the swing angle of the link member and, in turn, the stroke amount of the chain guide relative to the fixed member, resulting in poor gear shifting.

However, changes in the stroke amount with respect to the swing angle due to adjustment of the swing range of the link member have a serious effect on shifting performance, and especially when the derailleur is equipped with a positioning mechanism, the difference between the positions set by this mechanism There was a problem in that the stroke amount with respect to the swing angle of the gear changed, making it impossible to perform proper gear changes.

The present invention was devised in view of the above-mentioned problems, and includes a support member that is attached to a fixed member so as to be freely movable and adjustable in the axial direction of a multi-stage sprocket, and a guide member that is fixed between the support member and the fixed member. An adjustment mechanism is provided to adjust the amount of movement relative to the member, and this adjustment mechanism allows the guide body to maintain a predetermined stroke amount with respect to the fixed member without causing any change in the stroke amount. By adjusting the movement, the chain guide body is placed in a position accurately facing each sprocket of the multi-stage sprocket during a speed change operation, so that the chain can be reliably replaced on each sprocket.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The bicycle derailleur of the present invention will be explained below with reference to embodiments shown in the drawings.

The derailleur shown in the drawing is a rear derailleur, in which a support member 2 is swingably supported via a first pivot shaft 3 on a fixed member 1 fixed to a fork end of a bicycle. 2 to 1
Two link members 6, 7 via a pair of pins 4, 5
are pivotally mounted, and at the tips of each of these link members 6, 7,
A movable member 10 is supported via a pair of pins 8 and 9 so as to be freely movable in the axial direction of a multi-stage sprocket installed on the bicycle, and a chain guide having a guide pulley 12 and a tension pulley 13 is attached to the movable member 10. The body 11 is supported via a second pivot shaft 14 so as to be freely swingable.

In the derailleur constructed as described above, the first pivot shaft 3 supporting the support member 2 is rotatably attached to the fixed member 1, and the first pivot shaft 3 shown in the drawings is A threaded portion 31 is provided on the threaded portion 31, and an adjustment body 15 having a notch such as a knurling or the like formed on the outer circumferential surface to form the operating portion 15a is screwed into the threaded portion 31, and the support member 2
is loosely fitted into the threaded portion 31 of the first pivot shaft 3, and the support member 2
is adjusted to a predetermined position in the length direction of the first pivot shaft 3, and can be fixed at this adjusted position.

The support member 2 is mainly formed by pressing a steel plate, and has through holes 21 and 22 that loosely fit into the threaded portion 31 of the first pivot shaft 3, as shown in FIG. plates 23, 24
are opposed to each other with an interval wider than the wall thickness of the adjusting body 15, and one side of the mounting plates 23 and 24 is connected, and the mounting plate 2 is connected from this one side.
A pair of link support plates 25 and 26 having planes perpendicular to the planes 3 and 24 are arranged in series.
The threaded portion 31 of the first pivot shaft 3 includes:
The mounting plates 23 and 24 are provided with two flat parts so as to have a non-circular cross section, and the through holes 21 and 22 are shaped to match the cross-sectional shape of the threaded part 31.
is loosely fitted into the threaded portion 31 in a non-rotatable manner. This loose fit is the mounting plate 23, 24.
This is done by screwing the adjustment body 15 onto the threaded portion 31 with the adjustment body 15 interposed between the attachment plates 23, 24.
When the lock nut 16 reaches the desired position, the lock nut 16
It can be fixed in the above position by tightening.

In the above configuration, by loosening the lock nut 16 and rotating the adjustment body 15, the support member 2 can be fixed relative to the fixing member 1 via the mounting plates 23 and 24. It is moved in the axial direction of the support shaft 3, that is, in the axial direction of the multistage sprocket, and by this movement, the chain guide body 11 supported by the support member 2 via the link members 6, 7 and the movable member 10 is moved.
can be moved to adjust the position of each pulley 12, 13 relative to the sprocket.

In this adjustment, when the derailleur is designed to be top normal, each of the pulleys 12 and 13 is located on an extension line of the high speed (top) sprocket in the sprocket at the top position, that is, the high speed position. This is how we do it.

Further, the adjustment is performed by moving the entire pantograph mechanism consisting of the support member 2, the two link members 6 and 7, and the movable member 10 relative to the fixed member 1. The position of the movable member 10 with respect to, in other words, the link members 6, 7 with respect to the support member 2
Since the angle of the movable member 10 is not changed, the stroke amount of the movable member 10 with respect to the swing angle of the link members 6, 7, in other words, the stroke amount of each of the pulleys 12, 13 is a preset constant stroke without fluctuation. By operating the operating wire W, the chain can be changed over to one of the sprockets accurately and reliably.

In the figure, 17 is a fixture for the operating wire W, and 18 is a receiver for the outer tube O that guides the wire W. Further, reference numerals 19 and 20 are adjustment screws supported by the link member 6, and these adjustment screws 1
Reference numerals 9 and 20 are used to restrict the swing range of the link members 6 and 7 and to adjust the swing range according to the number of sprockets S and the like. Note that these adjustment screws 19 and 20 can be used in place of the adjustment screws 19 and 20 when the number of sprockets used is fixed, in other words, in a dedicated derailleur with a predetermined number of stages that does not require adjustment of the swing range. It is also possible to simply provide a long hole and a pin in the two members that move relative to each other so as to restrict the swing range of the link members 6 and 7.

Although the support member 2 is press-formed using a steel plate, it may also be formed by casting or die-casting, and the adjustment body 1 may be formed by forming a pair of mounting plates 23 and 24 between the mounting plates 23 and 24.
Although the adjustment body 5 is interposed therebetween, the adjustment body 15 and the lock nut 16 may be attached as one sandwiched between the adjustment body 15 and the lock nut 16.

As explained above, in the bicycle derailleur of the present invention, the supporting member is attached to the fixed member so as to be freely movable and adjustable in the axial direction of the multi-stage sprocket, and the position of the supporting member relative to the fixed member, in other words, the fixed member of the chain guide member is fixed. Since an adjustment mechanism is provided to adjust the position of the guide, even if the position of the guide is adjusted, the stroke amount of the guide does not change during a gear shift operation. By positioning the chain accurately opposite the sprockets, the guide can reliably replace the chain on each of the sprockets.

[Brief explanation of the drawing]

Fig. 1 is a front view of a bicycle derailleur according to the present invention, Fig. 2 is a partially cutaway bottom view, Fig. 3 is a bottom view showing the movement adjustment state of the chain guide, and Fig. 4 is a perspective view of only the support member. FIG. 5 is an explanatory diagram of a conventional example. DESCRIPTION OF SYMBOLS 1... Fixed member, 2... Support member, 10... Movable member, 6, 7... Link member, 11... Chain guide body.

Claims (1)

[Claims] 1 A support member is supported on a fixed member, a movable member is supported on the support member via two link members so as to be freely movable in the axial direction of a multi-stage sprocket mounted on a bicycle, and the movable member is provided with a movable member via two link members. In a bicycle derailleur that is equipped with a chain guide body that guides the chain,
The supporting member is attached to the fixed member so as to be movable in the axial direction of the multi-stage sprocket, and an adjustment mechanism is provided between the supporting member and the fixed member to adjust the position of the chain guide relative to the fixed member. A bicycle dayrailer characterized by: