JP2001328582A - Quick return crank device continuously effectively utilizing body weight and maintaining acceleration force by body weight in pedaling drive for bicycle and the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem such that body weight is not efficiently linked with rotational force because a gravity direction is at a substantially right angle with a rotating direction at the moment when the position of a pedal reaches a maximum point and the just before/just after and at the moment when the position reaches a minimum point and the just before/just after when pedaling a bicycle, and achieve a state that the one pedal already passes the maximum point is obtained when the other pedal is depressed up to the mini mum point. SOLUTION: Left and right cranks and a bearing of a chain ring are separated from each other. An elliptical slide gear having two slits across a center is fixed by a slide gear bearing and is rotated by left and right hooks integrated into each of the left and right cranks. The rotary shafts of the left and right hooks are the same and are made parallel to a rotary shaft of the chain ring. The hooks rotate the chain ring, sliding in the slits of the slide gear.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fast-return crank device which continues to effectively utilize the weight of a rotary pedaling drive portion of a bicycle or the like in the transmission of power from the left and right cranks to the chain and maintains the acceleration force due to the weight. About.

[0002]

2. Description of the Related Art Left and right cranks and a chain ring of a rotary pedal drive portion of a conventional bicycle or the like which is rowed by human power are integrated.

[0003]

In a conventional bicycle, a rickshaw or a rickshaw airplane to which the pedal is applied, when the pedal is pedaled, the position of the pedal reaches the highest point, immediately before, immediately after, and reaches the lowest point. At the moment, immediately before and immediately after, the direction of gravity is near or perpendicular to the direction of rotation, so applying weight alone does not produce a strong rotational force, and it is necessary to apply force forward near the highest point . And, when one of the left and right pedals is in this range, the other pedal is always in this range. Therefore, there is a problem that the weight cannot be used efficiently only when the pedal is in this range.

[0004] It is an object of the present invention to constantly convert the weight into a rotational force efficiently when pedaling in a bicycle or the like and maintain the acceleration force due to the weight.

[Means for Solving the Problems]

In order to achieve the above object, the left and right cranks (4) and a slide gear (2) corresponding to a chain ring portion of a conventional bicycle are separated in the rotary pedal drive portion of the present invention. The rotation axes (5) of the left and right cranks are on the same straight line, but the rotation axis (6) of the slide gear is at another parallel position.

The left crank has a structure in which the crank and the pedal are made smaller, and is integrated with the small crank (7) and the hook (3), and the right crank is the hook (3). The left and right hooks are slide gears (2)
In each of the slits (1) drilled outward from near the center. The rotation axis (6) of the slide gear is positioned inside the rotation track of the hook, and the rotation track of the hook is inside the rotation track of the outer edge of the slit of the slide gear. When the crank rotates, the hook rotates the slide gear (2) while sliding in the slit.

The slide gear has its central part removed so that the left and right cranks (4) and the slide gear (2) can rotate freely, and the crank shaft passes through it.

In the above eccentric crank device,
When the pedal (8) is depressed and the crank (4) is rotated,
As shown in FIG. 4, the left and right hooks (3) draw a circular orbit around the crank shaft (5), and the left and right hooks are always symmetrical about the slide gear rotation shaft (6). is there. When the slide gear (2) rotates at a constant speed, the pedal periodically changes its rotation speed during one rotation. As a result, one of the left and right pedals always moves within a certain angle D of 180 degrees or less about the rotation axis.

[0009] In this state, when the vehicle is traveling at a constant speed, FIG.
As shown in FIG. 4B, when the pedal is depressed from the highest point, the rotational speed of the pedal gradually decreases and then gradually increases. Therefore, by making the slide gear elliptical and adjusting the angle, FIG. As shown in (d), the speed of the pedal does not change so much when depressed. At this time, when the pedal goes up from the lowest point,
The rotation speed of the pedal becomes faster and faster than when the slide gear is circular, and then quickly falls past the midpoint and returns to the highest point.

The magnitude of the fixed angle D can be adjusted by adjusting the distance between the rotation axis (5) of the crank and the rotation axis (6) of the slide gear and the radius of rotation of the hook (3).

By adjusting the angle formed by the crank (4), the hook (3) and the rotating shaft, or the direction in which the rotating shaft (5) of the crank and the rotating shaft (6) of the slide gear are shifted, a constant angle D is set. The center of the constant angle D is set to a position where the weight is most efficiently utilized by the rotational force because the direction in which the pedal is positioned from the center of rotation of the pedal can be adjusted.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. In FIG. 1, the main components are a left crank (4) integrated with a small crank (7) and a hook (3), a right crank (4) integrated with a hook (3), a slide gear (2), A pedal (8), a frame (9), a rotary bearing (10) of a slide gear, and a bracket (11).

A slide gear bearing (10) is mounted on the frame (9) at a rotating bearing portion of the bracket.

The slide gear has an elliptical shape, the center of which is cut out in a round shape, and two slits (1) are formed outside the center of the slide gear so that the hooks can just fit therein.

The slide gear is supported by the slide gear bearing at a position where the bracket passes through a position slightly off the center of the hole.

Although the left crank is integral with the bracket, the right crank and the bracket are not integral and rotate freely. The left and right hooks are fitted one by one into the two slits of the slide gear. It is preferable that the hook rotates freely.

In the embodiment shown in FIG. 4, by providing a slit in the crank and a hook in the slide gear, the same effect as in the embodiment of FIG. 1 can be obtained.

[0018]

Since the present invention is configured as described above, it has the following effects.

When this device is mounted on a bicycle or the like,
There is no moment when one pedal is at the highest point and the other pedal is at the lowest point. When one of the pedals is depressed to the lowest point, the other pedal has already passed the highest point, and it has come to a point where it is easy to utilize the weight when depressing, so it is possible to efficiently convert weight to rotational power by shifting weight. , Can sustain the acceleration power.

[Brief description of the drawings]

FIGS. 1A and 1B are a side view and a front partial sectional view showing a structure of a quick-return crank device mounted on a pedal drive portion.

FIG. 2 is a diagram showing how the pedal moves when the slide gear rotates by 45 degrees in FIG. 1 and makes one rotation.

FIG. 3 is a diagram showing a change in pedal peripheral speed in a fast-return crank in which an eccentric crank and an elliptical slide gear are combined.

FIG. 4 is a side view (c) and a front partial sectional view (d) showing an embodiment in which a slit is provided on a crank and a hook is provided on a slide gear.

FIG. 5 is a diagram showing how the pedal moves when the slide gear rotates by 45 degrees in FIG. 4 and makes one rotation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slit 2 Slide gear 3 Left and right hooks 4 Left and right cranks 5 Crank rotation axis 6 Slide gear rotation axis 7 Small crank 8 Pedal 9 Frame 10 Slide gear bearing 11 Bracket

Claims (2)

[Claims] 1. A slide gear (2) having two slits (1) on a straight line across the center, and separately rotating while sharing a rotation axis slightly deviated from the center of the axis of the slide gear. An eccentric crank device in which hooks (3) of left and right cranks rotate the cranks while moving in corresponding slits. 2. A quick-return crank device according to claim 1, wherein the slide gear of the eccentric crank device according to claim 1 has an elliptical shape.