JPS586795Y2 - Multistage sprocket assembly - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multi-stage sprocket assembly, and more particularly, to a multi-stage sprocket assembly consisting of a cylindrical member and two or more sprockets of different diameters coupled to the outer periphery of the cylindrical member. .

Generally, in this type of assembly, the sprocket is coupled to the cylindrical member by forming a number of insertion grooves extending in the axial direction on the outer periphery of the cylindrical member, and by providing a screw on the outer periphery of one axial end of the cylindrical member. sprockets with protrusions on the inner periphery of the center hole are fitted sequentially at regular intervals starting from the large diameter sprocket via spacers, and a screw is provided on the inner periphery of the center hole of the smallest diameter sprocket to connect the sprocket to the cylinder. The sprockets are connected by screwing onto the threads of the cylindrical member, or by providing screws on the entire outer periphery of the cylindrical member and screwing all the sprockets.

Therefore, in the coupling structure configured as described above, the sprocket is firmly fixed to the cylindrical member, but among the plurality of sprockets adjacent to each other at a constant interval, the drive force between the sprockets with a small difference in the number of teeth is When changing the chain, start with the first sprocket, which has fewer teeth.
When changing to a second sprocket with a slightly larger number of teeth, with a difference in the number of teeth from 1 to 3, the chino cannot be properly replaced with the second sprocket and may climb over the second sprocket, resulting in the next sprocket being replaced. It was often replaced with the third sprocket.

Therefore, this invention was devised in view of the above phenomena.
The purpose is to provide a multi-stage sprocket assembly with good speed changeability that allows the drive chain to be changed reliably, with a difference in the number of teeth at least, and at least one of the sprockets is connected to the cylindrical member. The sprocket is supported so as to be tiltable in the axial direction of the sprocket, and an elastic body is interposed between the tiltable sprocket and the sprocket adjacent to the sprocket without providing a spacer.

Hereinafter, typical embodiments of the assembly of the present invention will be described based on the drawings.

In the figure, reference numeral 1 denotes a cylindrical member, which has a flange 11 protruding from one end in the axial direction, an annular groove 12 formed on the outer periphery of the other end, and a protruding portion of the flange 11 on the outer periphery. A plurality of insertion grooves 13 are formed that extend from the inside along the axial direction to the other end and open outward at the other end.

This cylindrical member 1 constitutes a driving member of a multi-stage freewheel as shown in FIG. 13 and ball races 15° and 16 provided on both sides in the axial direction.

Further, 2... are sprockets that are coupled to the cylindrical member 1 constructed as described above, and each of these sprockets 2...
* have different diameters, and a protrusion 21 that can be inserted into the insertion groove 13 is provided protruding from the inner periphery of the center hole.

These sprockets 2... may be fitted into the cylindrical member 1 independently through the protrusions 21, and assembled with a constant interval maintained by a spacer 3, but as shown in FIG. As shown, before inserting the sprocket 2 into the cylindrical member 1, except for the sprocket 2 with the smallest diameter, the other sprockets 2 are fixed in advance using connecting members 4 such as bolts/nuts or other caulking pins. They may be integrally connected at intervals to form a unit, and this sprocket unit may be inserted into the cylindrical member 1.

Among the sprockets 2 described above, the first sprocket 2a having the smallest diameter has a protrusion length of the protrusion 21 provided on the inner periphery of its center hole relative to the depth of the insertion groove 13, compared to the protrusion length of the other sprockets 2. 21 and supported so as to be tiltable in the axial direction of the cylindrical member 1,
Instead of providing a spacer 3, an elastic body 6 is interposed between the first sprocket 2a which is tiltable and the second sprocket 2b adjacent to the sprocket 2a.

Therefore, when changing the driving chain from the state in which the driving chain is engaged with the first sprocket 2a to the second sprocket 2b adjacent to the first sprocket 2a, the first sprocket 2a is When the chino is moved in the axial direction, this operating force causes the second sprocket to tilt in the direction of the second sprocket (2b).

As a result, the first and second sprocket) 2 a, 2
When the difference in the number of teeth of the chino is at least equal to b, the protruding part of the chino such as a pin hits the second sprocket rocket 2b that is engaged with the first sprocket 2a, and the chino is transferred to the second sprocket 2b,
The cheno will no longer climb over the second sprocket 2b, and the gears can be changed reliably.

During rotation, numeral 7 is a C-shaped ring that fits into the annular groove 12 of the cylindrical member 1 and prevents the first sprocket 2a from moving outward in the axial direction.

The assembly constructed as described above is used in combination with a driven member A having a pawl B as shown in FIG. 3 via a pair of balls D and E to form a multi-stage freewheel.

The multi-stage freewheel shown in Fig. 3 and configured as above is assembled into the rear wheel hub H, where S is the hub axle and P is screwed to the hub axle S. The ball presser R is a lock nut, and T is a tightening nut for fixing the hub axle S to the frame.

Also, in the embodiment described above, the first sprocket with the smallest diameter)
Although only sprocket 2a is made tiltable, one or more other sprockets 2 may also be made tiltable.

Further, although the assembly shown in the drawings constitutes a multi-stage freewheel as shown in Fig. 3, it may also constitute a front gear attached to the crank.

As described above, since the assembly of the present invention enables tilting of at least one sprocket, especially the smallest diameter sprocket as in the embodiment, the difference in the number of teeth between the sprocket and the next sprocket adjacent to the sprocket is at least During gear shifting, the sprocket is tilted in the direction of the next sprocket due to the moving force of the chain pushed in the axial direction by the gear shifting operation, and the chain engaged with the tilted sprocket is engaged with the sprocket next to the next sprocket. This means that the gears can be changed without any mistakes and with good gear shifting performance.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the assembly of the present invention;
FIG. 2 is a sectional view taken along the line ■--■ in FIG. 1, and FIG. 3 is a partial sectional view showing an example of application in a rear wheel hub. 1... Cylindrical member, 2... Sprocket, 6... Elastic body.

Claims (1)

[Scope of utility model registration request] A multi-stage sprocket assembly in which two or more sprockets with different diameters are non-rotatably assembled to a cylindrical member at regular intervals via spacers, at least one of the sprockets, Supporting the cylindrical member so as to be tiltable in the axial direction,
A multistage sprocket assembly characterized in that an elastic body is interposed between the tiltable sprocket and the sprocket adjacent to the tiltable sprocket without providing a spacer.