JPH06247371A - Driving device of bicycle - Google Patents

Abstract

(57) [Summary] [Purpose] The present invention relates to a bicycle crank mechanism,
The pedal movement of the companion foot can be performed only by a stroke angle of 180 ° or more so that the pedaling force can be reduced and the bicycle can be easily and inexpensively attached to the existing bicycle. A first crank 37 fixed to one end of a hanger shaft 32, a lever 40 fixed to the other end, and a lever 40
The eccentric collar 50 rotatably supported on the boss of the boss and the eccentric collar 50 can be freely rotated on the hamber shaft 32.
And a sprocket wheel 48 that is eccentric to the rear by d.
A second crank 42 swingably supported on the boss of the lever 40; a lever 40 and a second crank 42;
Rollers 43, 45 between sprocket wheel 48
And interlocking mechanism or pin 54,5 using the long groove 44,46
A bicycle driving device including an interlocking mechanism including 5,56,57 and links 58,59.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle drive device, and more particularly to improvement of a transmission mechanism between a crank rotatably driven by a foot pedal and a drive sprocket wheel.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 1-244994, shown in FIGS. 7 and 8, shows a first crank 13 at the left end of a hanger shaft 12 rotatably supported by a vehicle body 11. The lever 15 having the first roller 14 attached to the other end is fixed, and the second roller 16 is placed on the lever 15.
The second crank 17 to which is attached is rotatably mounted, and the bearing 18 supporting the right side of the hanger shaft 12 is provided on the inner circumference.
An eccentric member 21 having a bearing 20 for the sprocket wheel 19 which is eccentric to this is fixed to the vehicle body 11, and is engaged with the first roller 14 and the second roller 16 symmetrically in the diametrical direction on the sprocket wheel 19 side. Some have one radial guide 22 and a second radial guide 23. Further, as a very similar one, there is Japanese Patent Publication No. 24-4568, which is not disclosed here.

As shown in FIG. 8, the function of the sprocket wheel and the first crank 13 is that the bearing 20 of the sprocket wheel and the hanger shaft 12 are eccentric by d.
Since the second crank 17 and the second crank 17 are interlocked with each other, when a person steps on the first crank 13 up to an angle of θa with respect to the vertical line, the second crank 17 already has the angle of θb with respect to the vertical line. That is, the left or right crank can be always rotated to a position where torque can be transmitted to a person, and the person can smoothly apply a propulsive force to the bicycle.

[0004]

However, as shown in FIG.
The conventional bicycle drive mechanism shown in FIG. 8 requires a hanger shaft 12 and an eccentric member 21 different from those for a normal bicycle shown in FIG. Has a problem that it is expensive and cannot be attached to an existing bicycle. Further, in the ordinary bicycle shown in FIG. 7, the bearing of the hanger shaft 2 generally bears only the weight of a person, whereas in the conventional bicycle drive mechanism shown in FIG. If the ratio between the distance between the second roller 16 and the second roller 16 and the pedal is approximately 1: 2, the bearing 18 is loaded with approximately twice the weight of the pedal, which is normal. It was an unbearable load on the bicycle hanger bearing. Further, in the conventional bicycle drive mechanism shown in FIGS. 8 and 9, when one crank is stepped toward the bottom dead center, the other crank is in a position advanced from the top dead center. This inevitably means that a bicycle using this drive mechanism will perform the same work as the work at a stroke of 180 ° in the conventional bicycle shown in FIG. 7 with a stroke angle smaller than 180 °, and the required pedal force will be Becomes larger than the general. This increase in pedal effort was painful for a long ride.

In view of the above problems, the present invention focuses on the fact that a person can step on a bicycle crank with a stroke angle of more than 180 ° with one foot to transmit power, and the pedal force can be small, and the cost can be further reduced. Another object of the present invention is to provide a bicycle drive device that can be attached to an existing bicycle and has no hanger shaft bearing life.

[0006]

In order to achieve the above object, the present invention provides a lever fixed to one end of a hanger shaft, a second crank swingably supported on a boss of the lever, and a lever. From an eccentric collar supported on the boss, a detent for the eccentric collar, a sprocket wheel rotatably supported on the eccentric collar, and an interlocking mechanism arranged between the sprocket wheel and the lever and the second crank. Become. The direction of eccentricity of the eccentric collar is arranged so that when one crank is stepped to the bottom dead center, the other crank is behind the top dead center.

[0007]

Since the present invention has the above-mentioned structure, the right crank can be removed from the conventional ordinary bicycle, the mechanism constructed on the lever can be attached, and the eccentric collar detent may be attached to the vehicle body. You can This simple installation provides an inexpensive mechanism. Then, when a person steps on the left and right cranks, the lever and the second crank move at a non-constant speed with respect to the sprocket wheel, so that when one crank reaches the bottom dead center, the other crank tops. Since the point has not been reached, the effective crank stroke angle increases, the required pedaling force decreases, and the bicycle can be driven with a smaller force than before.

Moreover, the life of the hanger shaft bearing of the conventional ordinary bicycle is not shortened.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to.

Reference numeral 31 denotes a vehicle body frame, which is a hanger shaft 3
Reference numeral 2 is rotatably supported by the bearings 33 and 34 by disengaging the balls 35 and 36. The first crank 37 is fixed to the hanger shaft 32 by a square taper portion 38. Here, the parts 31 to 38 are the same as the parts of the conventional ordinary bicycle shown in FIG. The lever 40 is firstly attached to the square taper portion 39 at the right end of the hanger shaft 32.
The crank 37 is fixed in the same direction. Lever 40
A second crank 42 is attached to the outer boss portion of the No. 2 via a roller bearing 41, and a long groove 44 with which the second roller 43 engages is provided at the root of the second crank 42. On the other hand, the lever 40 is provided with a long groove 46 with which the first roller 45 is engaged.

Further, an eccentric collar 50 for rotatably supporting a sprocket wheel 48 by means of a roller bearing 49 via a roller bearing 47 is attached to the inner boss portion of the lever 40. A large circular sprocket 48a and a small sprocket 48b are mounted on the sprocket wheel 48. The shaft center of the hanger shaft 32 and the shaft center of the sprocket wheel 48 are eccentrically moved backward by d by an eccentric collar 50, and the eccentric collar 50 is prevented from rotating with respect to the vehicle body frame 31 by a detent metal fitting 51. ing. A first roller 45 and a second roller 43 are arranged on the sprocket wheel 48 at a radius r from the center of rotation in a direction of 180 ° with respect to each other, and engage with the first long groove 46 and the second long groove 44, respectively. However, the rotational positional relationship among the first crank 37, the second crank 42, and the sprocket wheel 48 is restricted.

Next, the operation will be described. As shown in FIG. 1, when the rollers 43 and 45 on the sprocket wheel 48 are arranged in the vertical direction, the first crank 37 is at a position retracted by an angle θb with respect to the vertical direction which is the top dead center. The crank 42 is located at a position retracted by an angle θa from the vertical direction which is the bottom dead center. When the second and second roller mounting radii are 50 mm and the eccentricity d is 5 mm, θa and θb are about 6 °.

From this state, a person depresses the left pedal to rotate the first crank 37 in the direction of arrow A, and the second crank 42 and the first crank 37 are in a horizontal state, and then the second crank of FIG. The first crank 3 up to the angle where the crank 42 was
When 7 is rotated, the motion of the first crank 37 is transmitted to the second crank 42 via the hanger shaft 32, the lever 40, the first roller 45, the sprocket wheel 48, the second roller 43, and the second crank 42. 42 rotates to the angle where the first crank 37 of FIG. 1 was. During this time, the sprocket wheel 48 rotates 180 °. Similarly, the second crank 42 is moved from the angular position of the first crank 37 in FIG. 1 to the second crank 42 in FIG.
When a person steps forward and downward to the angle position of 1, the first crank turns backward to the position of the first crank 37 in FIG. 1 and returns, completing one cycle.

Next, a second embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. The basic configuration of the second embodiment is
Similar to the first embodiment, but as the interlocking mechanism between the lever 40 and the sprocket wheel 48 and between the second crank 42 and the sprocket wheel 48, the engagement of the rollers 43 and 45 with the long grooves 44 and 46 is performed. Instead of the so-called crank slot mechanism, the lever 40 and the second crank 4
2, crank pins 54 and 55 are provided at positions of radius r from the center of the hanger shaft 32, and wheel pins 56 and 57 are provided at positions of radius r from the center of the sprocket wheel 48 in 180 ° directions with respect to each other. A so-called drag link mechanism is formed by connecting the links with links 58 and 59. At this time, a so-called drag link mechanism, which is connected by the links 58 and 59, is configured. At this time, it is preferable in terms of traveling feeling that the links 58 and 59 are combined in a direction in which a compressive force acts on the links during normal traveling of the bicycle.

The operation of the second embodiment of the present invention thus constructed is almost the same as that of the first embodiment, but the non-uniform motion between the crank and the sprocket wheel is the same as that of the first embodiment. Subtly differently, the pedaling force of a person near the bottom dead center of the crank is larger than that at near the top dead center, and the propulsive force can be more effectively given to the bicycle. In addition, in the first embodiment, the roller 4
There is a risk that sand will be caught between the grooves 3, 45 and the long grooves 44, 46, but this is not the case in the second embodiment.

Next, a third embodiment of the present invention will be described with reference to FIG. The basic configuration of the third embodiment is similar to that of the first embodiment, but the arrangement of the mechanism on the hanger shaft 32 in the first embodiment is from the side close to the bearing one 34 to the eccentric collar 50, the lever 40, Second crank 4
In the third embodiment, the eccentric collar 50, the second crank 42, and the lever 40 are arranged in this order. The operation of the third embodiment of the present invention thus configured is the same as that of the first embodiment.

Further, FIG. 5 shows a fourth embodiment of the present invention.
The description will be made with reference to FIG. The basic configuration of the fourth embodiment is also the same as that of the first embodiment, but the arrangement of the mechanism on the hanger shaft 32 is such that the eccentric collar 50, the lever 40 and the second one are arranged from the side closer to the bearing one 34. The cranks 42 are arranged in an overlapping manner. Specifically, as shown in the perspective view of FIG. 6, the levers 40 are laid out in a notch of the boss portion of the second crank 42 in an overlapping manner. The operation of the fourth embodiment thus configured is the same as that of the first embodiment.

Further, a fifth embodiment of the present invention will be described. Large sprockets 48 for the first to fourth embodiments
Although it has been described that the a and the small sprocket 48b use circular sprockets, instead of this, elliptical sprockets are used.
A desired ride can be obtained by appropriately changing the ratio of the major and minor axis lengths of the ellipse and the mounting angle while combining with the first to fourth embodiments.

[0019]

According to the drive device of the present invention, the lever is provided at one end of the hanger shaft as described above, and the sprocket wheel is eccentrically supported rearward from the hanger shaft on the boss of the lever to support the second crank. Since the boss of the lever 40 is configured to be swingable and the non-uniform velocity motion mechanism is configured between the sprocket wheel and the lever and between the second cranks, the eccentricity is eliminated by removing the second crank of the conventional ordinary bicycle. The drive device of the present invention can be easily installed only by adding the detent of the collar, and there is no problem in the life of the hanger shaft bearing of the conventional ordinary bicycle, which enables inexpensive supply. (EN) Provided is a bicycle drive device which requires a small pedaling force of a crank.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention in a state where cranks are vertically symmetrically positioned.

FIG. 2 is a cross-sectional plan view in a horizontal plane with the crank in a horizontal state according to the first embodiment of the present invention.

FIG. 3 is a front view showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional plan view in a horizontal plane with the crank in a horizontal state according to the third embodiment of the present invention.

FIG. 5 is a cross-sectional plan view in a horizontal plane showing a fourth embodiment of the present invention with the crank in a horizontal state.

FIG. 6 is a perspective view showing a combination of parts of main parts of a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional plan view in a horizontal plane showing a conventional bicycle drive mechanism with the crank in a horizontal state.

FIG. 8 is a front view showing a conventional bicycle drive mechanism in which the cranks are vertically symmetrical.

[Explanation of symbols]

 32 Hanger Shaft 37 1st Crank 40 Lever 42 2nd Crank 43,45 Roller 44,46 Long Groove 48 Sprocket Wheel 50 Eccentric Collar 51 Rotation Stopper

Claims (2)

[Claims] 1. A hanger shaft rotatably supported, a first crank fixed to one end of the hanger shaft, a lever fixed to the other end of the hanger shaft, and swingably supported on a boss of the lever. The sprocket wheel bearing is rotatably supported on the second crank and on the boss of the lever, and the outer circumference is eccentric from the hanger shaft axis. , A sprocket wheel, and an interlocking mechanism provided between the sprocket hole and the lever and between the lever and the second crank, in which a roller is arranged on one side and a groove for engaging the roller is arranged on the other side. Is arranged so that when one of the cranks is stepped in the direction of the bottom dead center, the other crank is positioned 180 degrees behind the opposite direction. 2. The drive device for a bicycle according to claim 1, wherein the interlocking mechanism comprises a so-called drag link mechanism in which the sprocket wheel, the lever, and the second crank are respectively connected by one link.