JPS6159952B2 - - 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 the rear wheel is driven at a predetermined gear ratio by a chain transmission during forward rotation to cause the bicycle to travel, and the brake is actuated to stop the bicycle when the bicycle is rotated in reverse.

Conventionally, a brake is built into the rear hub, a plurality of rear gears are provided in the brake actuating body that operates the brake, and a chain transmission with two pulleys is provided near the rear gear to control the rear gear. A drive chain is hung between one of the wheels and the front gear, and this drive chain is hung on the pulley,
The chain transmission shifts the chain to one of the rear gears, drives the rear hub at a predetermined gear ratio by forward rotation of the front gear, and reverses the rear gear by reversing the front gear; There has been provided a driving and braking device in which the brake actuating body is then actuated by reversing the gear 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 the chain is always under tension.
When braking is performed by reversing the front gear, the chain hanging from the pulley of the chain transmission becomes the drive side of the chain and is pulled. The rear gear is oscillated to the maximum extent against the shifting, and after this oscillation, the rear gear is reversely rotated.

Therefore, even if the front gear is rotated in the reverse direction, the rear gear does not rotate in the reverse direction while the reversible frame is oscillating, so there is a problem in that braking is delayed. The rotation angle of the front gear during braking, in other words, the rotation angle of the crank, differs depending on the gear ratio, which poses the problem of not being able to perform stable braking.

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

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 is rotated and driven together with the front gear during braking.
However, this device requires an extra front braking gear, rear braking gear, and braking chain.
The problem was that the structure was complicated and the cost was high.

The present invention was devised in view of the above-mentioned conventional problems, and its purpose is to eliminate the need for a front braking gear, a rear braking gear, and a braking chain.
By eliminating chain slack during braking, it is possible to eliminate slippage of the front gear and dropout of the chain when transitioning from the braking system to the driving system, and furthermore, there is no delay in braking, and moreover, the chain is not hung during braking. To provide a device capable of stably braking at a constant rotation angle even if the gear ratios of the front and rear gears are different.

Accordingly, the present invention supports a plurality of rear drive gears on the hub body of a rear hub equipped with a coaster brake so as to be freely rotatable in one direction, and extends radially outward of the hub body on a brake operating body. a chain transmission having two pulleys for switching a drive chain to one of the rear gears; At least one of the pulleys is capable of free rotation only when the drive chain moves in the forward drive direction, and when the drive chain moves in the opposite direction, the arm swings to operate the brake. It is.

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

In the figure, 1 is the rear hub of a bicycle equipped with a coaster brake, and 2 is attached to the hub body 11 of the hub 1 via a one-way rotation transmission mechanism 21 consisting of a ratchet and a pawl as shown in FIG. 3 is the rear gear for driving, and 3 is the crankshaft 4 of the bicycle.
a front gear attached to said front and rear gears 2,
3 are provided with two drive chains C, which are suspended between the front and rear gears 2 and 3, and are connected to either of the front and rear gears 2 and 3 by a chain transmission 5 and a front derailleur (not shown). By switching between the two gears, the power generated by 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.

As shown in FIG. 2, the rear hub 1 has a clutch cone 12, a brake shoe 13, and a brake cone 14 fixed to the frame inside the hub body 11, and the clutch cone 12 has one end attached to the hub. It is screwed into a brake actuating body 15 that protrudes axially outward from the barrel 11, and this actuating body 15
An arm 6 extending outward in the radial direction of the hub body 11 is provided on a protrusion of the hub body 11, and swinging of the arm 6 in one direction causes the actuating body 15 to rotate in the opposite direction, thereby moving the clutch cone 12 toward the brake shoe. The brake shoe 13, which is moved in the direction 13 and engaged with the brake cone 14, is pressed against the inner surface of the hub body 11 to brake the hub body 11. A return spring 7 is interposed between the arm 6 and the bicycle frame F supporting the rear hub 1 or a fixing member of the rear hub 1 to bias the arm 6 in one direction.
During braking, the arm 6 is moved against the force of the return spring 7.

Further, the rear gear 2 attached to the rear hub 1 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.

The chain converter 5 is provided at the tip of the arm 6, and has two first and second pulleys 51 and 52 for changing the drive chain C to one of the rear gears 2. The replacement frame 53 is supported by the arm 6 via the support horizontal shaft 8 so as to be freely swingable, and is freely movable in the axial direction of the support horizontal shaft 8,
And the tension spring 54 interposed between the arm 6 and the replacement frame 53 allows the replacement frame 5 to be
3 is energized in one vertical direction.

Therefore, the support horizontal shaft 8 that supports the hanging frame 53
is supported by the arm 6 via a pair of flanged bearings 9, 9, the tip of the arm 6 is bent into a U-shape, and the bearings 9, 9 are attached to the U-shaped tip. A large number of concave and convex strips 8 are provided on the outer periphery of both ends of the horizontal support shaft 8 which is fixed and supported by these bearings 9, 9.
1, 82, and these uneven stripes 81, 8
The uneven strips 91, 92 that fit into the bearings 9, 9
The support horizontal shaft 8 is formed on the inner periphery of the bearings 9, 9.
A circular support part 84 is provided on the outer periphery between the uneven strips 81 and 82 of the support horizontal shaft 8 via a step part 83, and the support part 84 is provided with a circular support part 84 that can be moved freely only in the axial direction. One end of the frame 53 and the first pulley 51 are supported in a freely rotatable manner. Further, the tension spring 54 is interposed between the hanging frame 53 and the bent tip of the arm 6 that supports one of the bearings 9, so that the hanging frame 53 is supported by the supporting horizontal shaft 8. Always energized in one vertical direction centered on
A constant chain tension is given to the drive chain C. Further, a one-way rotation transmission mechanism 55 consisting of a ratchet and a pawl is provided between the first pulley 51 and the horizontal support shaft 8, so that the first pulley 5
1 is allowed to freely rotate only when the drive chain C moves in the forward driving direction, and when the drive chain C moves in the opposite direction, the free rotation of the first pulley 51 is prevented and the gear 3 is reversely rotated. The rotational force at the time is applied directly from the first pulley 51 to the arm 6 via the horizontal support shaft 8, so that the hanging frame 53 does not swing in the opposite direction of movement of the drive chain C. This eliminates slack in the drive chain C when the front gear 3 is reversed.

On the other hand, the hanging frame 53 of the chain converter 5 is moved in the axial direction of the horizontal support shaft 8 by pulling the operating wire W.
One end is attached to an operating body 10 consisting of a bell crank, and one end of this operating body 10 is brought into contact with one end surface of the horizontal support shaft 8, so that the pulling force of the operating wire W is applied to the operating body 10 through the operating body 10. The transmission is transmitted to the support horizontal shaft 8, and the support horizontal shaft 8 is moved in one direction in the axial direction, and the above-mentioned hanging frame 53 is moved through the stepped portion 83.
and the first pulley 51 is connected to the return spring 54
The drive chain C, which is hung on the pulleys 51 and 52, is replaced by one of the rear gears 2.

In the figure, 41 is a crank arm fixed to the crankshaft 4, 20 and 20 are lock nuts of bearings 9, 9,
C is an outer tube for guiding the operation wire W, 30
is a support that supports this outer cylinder O.

The present invention is constructed as described above, and when the pedal is depressed in the forward direction (clockwise in Figure 1) to rotate the crankshaft 4 in the forward direction, the front gear 3 rotates in the forward direction, and this rotational force is transmitted through the drive chain C. This is directly transmitted to the rear driving gear 2 to drive the hub body 11, and the bicycle is made to travel forward at a predetermined gear ratio, as in the past. At this time, the first pulley 5 of the chain converter 5
1 is freely rotated by the one-way rotation transmission mechanism 55, so that the drive chain C can be moved smoothly.

When braking is to be done, the pedal is reversely depressed to reverse the crankshaft 4, as in the past.This reversal of the crankshaft 4 causes the front gear 3 to reverse, and this rotational force drives the drive chain C. The signal is transmitted directly to the first pulley 51 of the chain converter 5 through the chain converter 5, and free rotation of the first pulley 51 is prevented by the one-way rotation transmission mechanism 55.
As the drive chain C acting on the pulley 51 moves in the braking direction, the arm 6 swings, and the brake actuating body 15 rotates in the opposite direction, moving the clutch cone 12 in the direction of the brake shoe 13. The braking is reliably performed by the movement and the above-described action. At this time, when the drive chain C moving in the braking direction moves from the front gear 3 through the rear gear 2 toward the second pulley 52 of the chain transmission 5, the chain converter 5 hanging frame 53 is moved to the tension spring 54. The force causes the drive chain C to swing clockwise in FIG. 3, eliminating slack in the drive chain C.

In the above embodiment, the rear drive gear 2 is connected to the hub body 1 of the rear hub 1 via the one-way rotation transmission mechanism 21.
In addition, as shown in FIG. 4, one end of the drive body 22 that supports the rear gear 2 is inserted into the hub shell 11, and the inner surface of the hub shell 11 is inserted into the outer periphery of this protrusion. 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 1 is rotated by the rotational force from the hub body 11.
6 may be moved relative to one side in the axial direction (towards the clutch cone 12 in FIG. 4) with respect to the drive body 22, so that the rear gear 2 can freely rotate. According to this structure, since there are no pawls, it is possible to completely eliminate the locking phenomenon during braking. In other words, when 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. 2, when the forward rotation of the rear gear 2 stops during braking, the pawl Although there is a possibility that the rear gear 2 cannot be rotated in the normal direction when the gear is locked while engaged with the ratchet and transferred from the braking system to the driving system, by using the driving clutch cone 16, it is possible to lock the rear gear 2. The phenomenon can be eliminated.

As described above, since the present invention performs braking using the drive chain suspended between the front gear and the rear drive gear, the conventional brake chain, rear brake gear, and front brake gear can be eliminated. Therefore, the structure becomes simple and costs can be reduced. However, in the present invention, an arm is provided on the brake operating body, and a chain converter is provided on this arm, and when the front gear is reversed, free rotation of the pulley in the chain transmission is prevented, and the arm is swung to perform braking. It is possible to eliminate the slack of the drive chain during braking, and therefore to prevent the front gear from slipping and the chain from falling off when transitioning from the braking system to the driving system. Furthermore, when braking, the arm can be swung in the braking direction 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 remains constant regardless of the gear ratio. This allows for stable braking.

[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 an enlarged partially cutaway rear view of the rear hub side shown in Fig. 1, Fig. 3 is an enlarged side view thereof, and Fig. 4. FIG. 7 is a partially cutaway front view showing another embodiment of the rear hub. 1... Rear hub, 11... Hub body, 15... Brake operating body, 2... Rear gear, 3... Front gear, 5...
...Chain converter, 51, 52...Pulley, 6...
...Arm, C...Drive chain.

Claims (1)

[Claims] 1. A plurality of rear drive gears are supported on the hub body of a rear hub equipped with a coaster brake so as to be freely rotatable in one direction, and an arm extending radially outward of the hub body is provided on the brake actuation body, The brake is actuated by the swinging of the arm, and the arm is provided with a chain transmission having two pulleys for switching the drive chain to one of the rear gears, and at least one of the pulleys is provided. Driving and braking of a bicycle, characterized in that the driving chain is capable of free rotation only when moving in the forward driving direction, and when moving in the opposite direction, the arm is swung to operate the brake. Device.