JPH0340713Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a toothed pulley that is attached to the crank or rear hub of a bicycle. Specifically, the invention is a toothed pulley that is attached to the crank or rear hub of a bicycle. This invention relates to a toothed pulley provided around the periphery.

(Prior Art) Generally, when a toothed belt is hung between a driving side toothed pulley and a driven side toothed pulley and the driven side toothed pulley is driven via this toothed belt,
The toothed belt has a tendency to lean toward one side with respect to the tooth width center of the toothed pulley. A large-diameter annular splint is attached to prevent the toothed belt from coming off the toothed pulley.

In addition, in the case of a bicycle, when the bicycle is running, muddy water thrown up by the wheels hits the teeth of the toothed pulley, and this muddy water may accumulate at the bottom of the teeth. As seen in the publication, a discharge hole is arranged in a row at a position corresponding to the tooth bottom of each tooth in the appendix, and muddy water etc. that have entered the tooth bottom are discharged from the discharge hole to the outside of the appendix. It is known that it was made to do so.

(Problems to be Solved by the Invention) However, the conventional toothed pulley described above uses an appendage with a large number of discharge holes, and this appendage is shaped so that the dedendum circle can form the discharge holes. It is formed into an annular shape with a smaller diameter inner circumferential surface and is attached by caulking etc. to the side of the pulley body and at a position displaced toward the center with respect to the bottom of the tooth. Then, since the attachment part is located far away from the center of the toothed belt's contact area with the splint, if the toothed belt moves to one side with respect to the toothed pulley, the attachment of the splint will be difficult. There is a problem that a large force is applied to the pulley, which causes it to easily separate from the pulley body.Also, since the structure has a discharge hole at a position corresponding to the bottom of each tooth, when installing the accessory, each discharge hole There was a problem in that it was difficult and time-consuming to align the teeth corresponding to the bottoms of each tooth.

The purpose of this invention is to be able to drain muddy water etc. that has entered the tooth bottom to the outside of the insert, and to
The force acting from the toothed belt on the mounting portion of the splint can be reduced, and the splint can be easily mounted without alignment.

(Means for Solving the Problems) Therefore, the present invention is a toothed pulley in which a large number of teeth 2 are provided around the outer periphery of a pulley body 1 to mesh with the teeth of a toothed belt. A catch seat 12 is provided on the side face in the tooth width direction of the tooth 2 and at a position displaced toward the tooth tip side with respect to the tooth bottom. The attachment member 4 is attached so that the bottom of each tooth 2 is opened outward in the tooth width direction.

(Function) A catch 12 is provided on the pulley body, and this catch 1
Since the annular splint 4 is attached to the annular splint 4 at the time of attachment, it is possible to prevent the annular splint 4 from displacing in the radial direction, and also to hold the inner periphery of the annular splint 4.
The installation can be made stronger. Further, since the annular splint 4 can be attached at a position close to the contact portion with the toothed belt that meshes with each of the teeth 2, the toothed belt acts on the attachment portion of the annular splint 4. The force can be reduced, and therefore the catch seat 12
Coupled with the fact that it can be firmly attached to the belt, the force from the toothed belt can be strongly resisted, and the annular splint 4 can be prevented from coming off. Furthermore, since the annular splint 4 having an arcuate inner surface with a diameter larger than the dedendum circle is used, the annular splint 4 can be easily attached without having to be aligned with each tooth root.

(Embodiment) In the figure, reference numeral 1 denotes a pulley body having a mounting hole 11 on the center side, and a large number of teeth 2 on the outer periphery of the pulley body 1 that mesh with teeth 31 of a toothed belt 3.
is established.

Therefore, the catch seat 12 is located on the side surface in the tooth width direction of each tooth 2 and at a position displaced toward the tooth tip side with respect to the tooth bottom.
An annular splice 4 having an annular inner surface 41 with a diameter larger than the root circle is attached to this seat 12, and the bottom of each tooth 2 is opened outward in the tooth width direction. .

The support member 4 is formed into an annular shape mainly from a metal plate. Moreover, this attachment 4 is supported by a seat 12 provided on the side surface of the tooth 2 as shown in FIGS. 2 and 3, and is attached by caulking the vicinity of the edge of the seat 12. The attachment means is not particularly limited.

In addition, the illustrated one is provided with a fitting protrusion 12 extending in the axial direction in the attachment hole 11 of the pulley main body 1,
A retaining ring 52 is fitted to the outer periphery of a driving body 51 of a rear hub 5 of a bicycle in a relatively non-rotatable manner, and a retaining ring 52 is fitted into an annular groove 51a provided in the driving body 51 to prevent movement in the axial direction. It may be screwed onto the outer periphery of the drive body 51.

Although the splint 4 is attached to the side surface of the tooth 2 in the tooth width direction, it may be attached only to one side surface.
In addition, when provided on both sides, one splice is attached to the tooth 2.
It may be formed integrally with.

In addition to being attached to the rear hub 5, the toothed pulley of the present invention may be attached to the crank.

(Effects of the invention) As described above, the present invention provides the catch seat 12 on the side surface in the tooth width direction of each tooth 2 provided around the outer periphery of the pulley body 1, and at a position displaced toward the tooth tip with respect to the tooth bottom. hand,
This catch seat 12 has an annular inner surface 41 with a diameter larger than the tooth root circle.
Since the annular splice 4 having a
When the annular splint 4 is attached, it is possible to prevent the annular splint 4 from displacing in the radial direction, and the inner periphery of the annular splint 4 can be held, thereby making it possible to firmly attach the annular splint 4. Since the annular splint 4 can be mounted at a position close to the contact portion with the toothed belt that meshes with each tooth 2, the force acting from the toothed belt on the attachment portion of the annular splint 4 can be reduced. It can be made smaller. Therefore, in addition to being able to be firmly attached to the seat 12, it can also strongly resist the force from the toothed belt, prevent the annular splint 4 from coming off, and can be used for a long period of time. It is.

Moreover, since the annular splint 4 having an arcuate inner surface with a larger diameter than the root circle is used, the annular splint 4 can be connected to the seat 1 without providing a drainage hole in the annular splint 4.
By simply attaching it to 2, the bottom of the tooth can be opened to the outside of the splint. For this reason, the annular splice 4 can be easily processed, and the annular splice 4 can be installed without aligning with each tooth bottom, and in addition, each tooth bottom can be moved outward in the tooth width direction. surely,
In addition, it can be opened straight, avoiding the inability to drain muddy water and the like.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing an embodiment of the pulley of the present invention, Fig. 2 is a sectional view taken along the line of Fig. 1, Fig. 3 is a sectional view taken along the line of Fig. 1, and Fig. 4 shows the rear hub. FIG. 3 is a partially cutaway side view showing the installed state. 1... Pulley body, 2... Teeth, 4... Additive,
41... Arc-shaped inner surface.

Claims (1)

[Scope of utility model registration request] This is a toothed pulley comprising a large number of teeth 2 arranged around the outer periphery of a pulley body 1 that mesh with the teeth of a toothed belt, and the tooth tip is located on the side surface in the width direction of each tooth 2 and with respect to the tooth bottom. A catch seat 12 is provided at a position displaced to the side,
This catch seat 12 has an annular inner surface 41 with a diameter larger than the tooth root circle.
A toothed pulley for a bicycle, characterized in that an annular splice 4 having a shape is attached, and the bottom of each tooth 2 is opened outward in the tooth width direction.