JPS6159953B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a bicycle drive and braking device, more specifically, a rear hub equipped with a coaster brake on the rear wheel side, a plurality of rear drive gears attached to the hub, and a rear hub equipped with a coaster brake. This invention relates to a driving and braking device for a bicycle, in which a chain converter drives the rear wheel at a predetermined gear ratio during forward rotation to make the bicycle travel, and when the bicycle rotates in reverse, the brake is actuated to stop the bicycle.

Conventionally, a brake is built into the rear hub, a plurality of rear gears are provided in the brake operating body that operates the brake, and a chain converter with two pulleys is provided near the rear gears to convert the rear gears. a drive chain is hung between one of the gears and the gear, the drive chain is hung on the pulley,
The chain is switched to one of the rear gears by the chain converter, and the forward rotation of the front gear drives the rear hub at a predetermined gear ratio, and the reverse rotation of the front gear reverses the rear gear. There has been provided a driving and braking device in which the brake actuating body is actuated by reversing the gears to perform braking.

By the way, in the above device, the chain converter is provided with a tension spring to apply a constant chain tension to the chain, so that no matter which gear of the rear gear the chain is changed to, the chain converter is provided with a tension spring. I am always nervous, but
When the front gear is braked by reversing the front gear, the chain hung on the pulley of the chain converter becomes the driving side of the chain and is pulled. The rear gear swings to the maximum extent against the action of the spring, and after this swing, the rear gear rotates in the reverse direction.

Therefore, even if the front gear is rotated in the reverse direction, the rear gear does not reverse rotation while the replacement frame is oscillating, resulting in a delay in braking. There was a problem with the converter being damaged due to excessive force acting on it, and since braking is performed by reversing the rear gear, the rotation angle of the front gear during braking, in other words, the rotation angle of the crank, varies depending on the gear ratio, making it unstable. There was also a problem in which it was not possible to perform proper braking.

Furthermore, during braking, the hanging frame swings to the maximum extent, so during normal rotation, the chain on the drive side becomes slack between the front gear and rear gear, resulting in a transition from the braking system to the driving system. Then, by the amount of slack,
As the front gear spun, the chain sometimes fell off from the front gear.

Conventionally, a front braking gear is attached to the crankshaft that supports the front gear, a rear braking gear is attached to the rear hub, and a braking chain is connected between the front braking gear and the rear braking gear. An apparatus has been proposed in which the braking front gear rotates together with the front gear to perform braking during braking.
However, this device requires an extra front braking gear and a braking chain, resulting in a complicated structure and high cost.

The present invention was devised in view of the above-mentioned conventional problems.The purpose of the present invention is to eliminate the need for a front braking gear and a brake chain, and to eliminate slack in the chain during braking, thereby changing the braking system to the driving system. It is possible to eliminate the slippage of the front gear and the dropping of the chain when switching to Even if the gear ratio is different, the rotation angle is always constant,
The purpose is to provide a device that can brake stably.

Therefore, the present invention has a rear hub of a bicycle equipped with a coaster brake, in which a plurality of rear driving gears are rotatable in one direction freely in the hub body, and the braking gears are fixed to the brake actuating body, and the front gear and the rear gear are fixed to the brake actuating body. A long first chain is hung between one of the gears and one of the braking gears, and a chain is connected to a chain converter and a pulley of the converter via a bracket near the rear gear. and a braking pulley that rotates integrally with the guide pulley during reverse rotation, and a short gear is provided between the braking pulley and one of the rear gears and one of the guide pulleys. It is characterized by hanging two chains.

Embodiments of the device of the present invention will be described below based on the drawings.

In FIGS. 1 and 2, 1 is a rear hub of a bicycle equipped with a coaster brake, and 2 is a unidirectional rotation transmission mechanism 21 consisting of a ratchet and a pawl on the hub body 11 of the rear hub 1, as shown in FIG. 3 is a front gear attached to the crankshaft 4 of the bicycle, and each of the front and rear gears 2 and 3 is provided with two gears. A long first chain C ₁ that is hung between the front and rear gears 2 and 3 is hung on one of the front and rear gears 2 and 3 by a chain converter 5 and a front derailleur (not shown). By switching, the power generated by the normal rotation of the front gear 3 can be transmitted to the rear gear 2 at a predetermined gear ratio to drive the rear wheels.

The rear hub 1 has a clutch cone 12 and a brake shoe 1 inside the hub body 11 shown in FIG.
3 and a brake cone 14 fixed to the frame, the clutch cone 12 is screwed onto a brake actuating body 15 whose one end projects outward in the axial direction from the hub body 11, and when the actuating body 15 rotates in one direction, i.e. When the rear gear 2 rotates in the opposite direction to the normal rotation, the clutch cone 12 is moved in the direction of the brake shoe 13 and the brake shoe 13, which engages with the brake cone 14, is pressed against the inner surface of the hub body 11. The hub cylinder 11 is thereby braked.

Further, the rear gear 2 to be attached to the hub 1 after this is
As is known, it is attached to a cylindrical driving body 22,
The drive body 22 is rotatably supported by the hub body 11 via bearings 23 and 24, and the one-way rotation transmission mechanism 21 is provided between the drive body 22 and the hub body 11, and the rear gear 2 to drive body 22
The structure is such that rotation in one direction transmitted to the hub body 11 is transmitted to the hub body 11.

Further, the chain converter 5 is a bicycle frame F.
One pulley 51 is provided near the rear gear 2 via a bracket 6 fixed to the rear gear 2, and the pulley 51 hangs the first chain _C1 on one of the rear gears 2.
A support member 52 is supported by the bracket 6 via a vertical shaft 61 so as to be able to swing freely.
The support member 52 is supported so as to be able to swing freely via a horizontal shaft 53, and biased in one horizontal direction by a return spring 54 interposed between the bracket 6 and the support member 52. A tension spring 55 provided between the chain converter 5 and the chain converter 5 biases the chain converter 5 in one vertical direction. Also, this chain converter 5
is horizontally oscillated about the vertical shaft 61 by pulling the operating wire W, and this oscillation causes the first chain C1, which is hung on the pulley ₅₁ , to move from one of the rear gears 2 to the other. It can be replaced with one. Further, the hanging frame 50 of the chain converter 5 is always biased in one direction in the vertical direction about the horizontal axis 53 by the action of the tension spring 56, and the first chain _C1 is a constant chain. Tension is given.

The operating wire W is fixed to a fixture 62 attached to the bracket 6, and the outer tube O for guiding the operating wire W is supported by a support 56 attached to the support member 52. When the operating wire W is pulled, the outer cylinder O moves relative to the operating wire W, and a pressing force that causes the supporting member 52 to swing in the horizontal direction is generated on the outer cylinder O. This pressing force causes the supporting member 52 to swing. It makes the oscillate.

Further, in FIGS. 1 and 2, 7 is a braking gear fixed to the brake actuating body 15 of the rear hub 1;
9 is a guide pulley provided near the rear gear 2 via the bracket 6, and 9 is a braking pulley similarly provided near the rear gear 2 via the bracket 6.

Therefore, the braking gear 7 is configured to freely rotate independently of the rear driving gear 2 during normal rotation,
By reversing the braking gear 7, the brake actuating body 15 is rotated in the opposite direction to perform the above-described braking operation.

The guide pulley 8 guides the first chain C ₁ to the pulley 51 of the chain converter 5, and the braking pulley 9 is integrated with the guide pulley 8 when the front gear 3 is reversed. The guide pulley 8 and the brake pulley 9 are rotatably supported by the bracket 6 via a single horizontal support shaft 10. has been done. The braking pulley 9 may be formed integrally with the guide pulley 8 so that it rotates integrally with the guide pulley 8 when the front gear 3 rotates in forward and reverse directions. In addition, a clutch may be provided between the guide pulley 8 and the braking pulley 9, or a one-way rotation transmission mechanism may be provided so that when the front gear 3 rotates forward, the braking pulley 9 rotates freely relative to the guide pulley 8, and the front gear 3
The guide pulley 8 may rotate together with the guide pulley 8 only when the rotation is reversed.

However, the guide pulley 8 has the front gear 3
The first chain C1 is hung between one of the rear drive gears 2 and one of the rear driving gears 2.More specifically, the first chain _C1 is hung between one of the chain C1 and one of the rear drive gears ₂ . The chain coming out from the lower side of When the front gear 3 is reversely rotated, the rotational force is applied directly to the guide pulley 8, and when the front gear 3 is reversed, the hanging frame 50 is prevented from forcibly swinging, thereby eliminating chain slack.

Furthermore, a short second chain _C2 is hung between the braking gear 7 and the braking pulley 9, and the front gear 3
from the guide pulley 8 to the braking pulley 9 during reverse rotation.
The rotational force transmitted to the brake gear ₇ is transmitted to the brake gear 7 through the second chain C2, and together with the brake gear 7, the brake operating body 15 is rotated to perform the above-described brake operation.

In the figure, 41 is a crank arm fixed to the crankshaft 4, 57 is a chain holder having a chain holding surface 57a facing the outer peripheral surface of the guide pulley 8, and the chain holder 41 is connected to the bracket 6 via the horizontal support shaft 10.
It is swingably mounted on the

The present invention is constructed as described above, and when the pedal is depressed in the forward direction (clockwise in FIG. 1) and the crankshaft 4 is rotated in the forward direction, the front gear 3 rotates in the forward direction, and this rotational force is transferred to the first chain _C1. is transmitted directly to the rear drive gear 2 via the
As before, the bicycle is driven forward at a predetermined gear ratio. At this time, if the brake pulley 9 is structured to rotate together with the guide pulley 8,
The rotational force of the front gear 3 is applied to the guide pulley 8.
This is transmitted to the braking gear 7 via the braking pulley 9 and the second chain _C2 , and the brake operating body 15 rotates. The clutch cone 12 screwed into the body 15 serves as the brake shoe 1.
3 and rotates freely, so no braking action occurs at all.

Braking is performed by depressing the pedal in the opposite direction and reversing the crankshaft 4, as in the past, and by reversing the crankshaft 4, the front gear 3 is reversed, and this rotational force is transferred to the first chain _C1 . The force is transmitted linearly to the guide pulley 8 via the guide pulley 8, and is further transmitted from the guide pulley 8 to the brake gear 9 via the brake pulley 9 and the second chain _C2 , so that the brake actuating body 15 causes the rear drive gear 2 to rotate in the normal direction. On the other hand, the clutch cone 12 is rotated in the opposite direction to move the clutch cone 12 toward the brake shoe 13, and braking is reliably performed by the above-described action. At this time, the rotational force of the front gear 3 is transmitted from the guide pulley 8 to the rear drive gear 2 via the pulley 51 of the chain converter 5, but after this, the gear 2 freely rotates by the one-way rotation transmission mechanism 21. Therefore, there is no problem with the braking. Also, at this time, the rotational force of the front gear 3 is applied to the pulley 51 of the chain converter 5.
Since it acts on the braking gear 7 without passing through the braking process, rapid braking can be performed without any delay in braking, and the above-mentioned hanging frame 50 is not forcibly swung during braking, so that excessive force is not applied during braking. Moreover, there is no slack in the chain _C1 , so there is no risk of the chain _C1 falling off from the front gear when driving after braking, and the slipping of the front gear 3 can be eliminated. The rotation angle of the front gear 3 during braking can be kept constant, and stable braking can be performed.

In the above embodiment, a long first chain _C1 is hung between one of the front gears 3 and one of the rear drive gears 2, and a short chain C1 is hung between the braking gear 7 and the braking pulley 9. In addition, as shown in FIGS _{. 6 and 7, the first chain C 2 is} hung between one of the front gears 3 and the braking gear 7, and the drive The second chain C _{2 is hung between one of the rear gears 2 and the guide pulley 8, and this second chain C 2 is} meshed with the pulley 51 of the chain converter to connect the front gear 3 to the front gear 3. The rotational force at the time of rotation is transferred from the first chain _C1 to the braking gear 7,
The torque is transmitted to one of the rear driving gears ₂ via the braking pulley 9, the guide pulley 8 and the second chain C2, and the rotational force when the front gear 3 reverses is transmitted to the first chain C2.
Braking gear 7 via C ₁ and braking pulley 9
It may be structured as follows.

Further, in the above embodiment, the rear drive gear 2 is connected to the hub barrel 1 of the rear hub 1 via the one-way rotation transmission mechanism 21.
In addition, as shown in FIG. 8, one end of the drive body 22 that supports the rear gear 2 is thrust into the hub shell 11, and the inner surface of the hub shell 11 is attached to the outer periphery of this plunged part. A drive clutch cone 16 that is in contact with the front gear 3 is screwed together, and the rotational force when the front gear 3 rotates in the normal direction is transmitted from the drive body 22 to the hub body 11 via the clutch cone 16. When the forward rotation of the rear gear 2 stops, the clutch cone 16 is moved relative to the drive body 22 to one side in the axial direction (the clutch cone 12 side in FIG. 8) by the rotational force from the hub body 11, and the rear gear 2 It may be configured so that it rotates freely.
With this structure, since there are no claws, it is possible to completely eliminate the locking phenomenon during braking. In other words, if the driving body 22 is supported on the hub body 11 via the one-way rotation transmission mechanism 21 consisting of a pawl and a ratchet as shown in FIG. When shifting from the braking system to the driving system, the driving clutch cone 16 cannot be rotated forward to the rear gear 2.
By using this, the locking phenomenon can be eliminated.

As described above, the present invention includes a long first chain hanging between one of the front gear and the rear driving gear and the braking gear fixed to the brake operating body, and a guide pulley near the rear gear. A braking pulley is provided, and a short second chain is hung between the braking gear and the braking pulley, and between one of the rear gears and one of the guide pulleys, so the conventional front braking gear is unnecessary. Moreover, since the brake chain can be significantly shortened, costs can be reduced.

However, the rotational force when the front gear reverses,
Since the signal is transmitted to the braking gear without passing through the pulley of the chain converter, slack in the chain during braking can be eliminated, thus preventing the front gear from idling and the chain from falling off when transitioning from the braking system to the driving system. can be eliminated. Moreover, when braking, the braking gear can be reversed at the same time as the front gear is reversed, so braking can be done quickly without any delay in braking.Furthermore, the rotation angle of the front gear during braking can be kept constant regardless of the gear ratio. This allows for stable braking. Furthermore, since no tensile force is applied to the chain converter during braking as in the conventional case, damage to the chain converter can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view showing an embodiment of the device of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is an enlarged side view of the rear hub side shown in Figs. 1 and 2, and Fig. 4 is its side view. FIG. 5 is a partially cutaway enlarged plan view, FIG. 5 is a partial front view of the guide pulley part, FIGS. 6 to 8 show other embodiments, FIG. The figure is a partially cutaway plan view thereof, and FIG. 8 is a partially cutaway front view of the rear hub. 1... Rear hub, 11... Hub body, 15... Brake operating body, 2... Rear gear, 3... Front gear, 5...
... Chain converter, 51 ... Pulley, 6 ... Bracket, 7 ... Braking gear, 8 ... Guide pulley, 9 ... Braking pulley, C ₁ ... First chain, C ₂ ... Second chain .

Claims (1)

[Claims] 1 A plurality of driving rear gears are fixed to the hub body of the rear hub of a bicycle equipped with a coaster brake so as to be able to freely rotate in one direction, and a braking gear is fixed to the brake actuating body, and the front gear and one of the rear gears are fixed to the brake actuating body. A long first chain is suspended between one side of the first chain and the brake gear, and a chain converter and a guide pulley that guides the chain to the pulley of the converter, via a bracket near the rear gear. and when reversed,
A braking pulley that rotates integrally with the guide pulley is provided, and a short second chain is hung between the braking gear and the braking pulley, and between one of the rear gears and one of the guide pulleys. A bicycle drive and braking device characterized by: