JPH1045083A - Crank construction of bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bicycle crank whose length is such that the length from a top dead center to a lower dead center is made longer than a standard length so that stepping forces can be utilized effectively as driving power. SOLUTION: A bicycle crank consturction has a fixed plate 5 fixed to a frame 13 by a mounting bracket 14, the fixed plate 5 being greater in diameter than a gear 4 secured to a crankshaft 3, and having a hole 7 bored in a position deviating outward from the center of the plate 5 to insert the crankshaft 3 into the hole 7, with a recessed groove 6 provided in its inner peripheral surface; an opening is provided in the center of a crank 2, an E-shaped lid 9 is attached to the opening by a screw, etc., an H-shaped clamp 10 that freely moves to the right and left is fitted into the opening and secured to each end of the crankshaft 3, a roller 11 that rotates in such a way as to freely slide within the groove 6 in the fixed plate 5 is mounted on the inner surface of the clamp 10, and a pedal 12 is mounted at the end of the clamp 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank structure capable of effectively using a depressing force as a driving force when depressing a driving pedal of a bicycle.

[0002]

2. Description of the Related Art A conventional bicycle crank structure is composed of a pair of cranks of a fixed length and a crank gear.
Depressing the drive pedal from the top dead center to the bottom dead center to rotate the crank gear to generate driving force, sequentially transmitting the driving force to the rear wheels via the chain and free gear applied to the crank, and driving the bicycle The technique for causing the above is generally known and widely used.

[0003]

However, in the above-mentioned prior art, since the drive pedal is rotated by depressing from the top dead center to the bottom dead center, the depressed area of the drive pedal is narrow, and the structure of the human foot is reduced. In view of the above, it is difficult to generate a large driving force, and even if the driving pedal is actually depressed, the range in which the depressing force can be effectively used as the driving force is limited, and the loss is considered from the viewpoint of energy efficiency. It can be said that it is big.

Accordingly, an object of the present invention is to make the length of the crank from the top dead center to the bottom dead center longer than the standard length, and to effectively use the stepping force as the driving force. It is intended to provide a bicycle crank that is possible.

[0005]

In order to solve the above-mentioned conventional problems, the crank structure of the bicycle 1 of the present invention has a larger diameter than the gear 4 fixed to the crankshaft 3,
The position is shifted from the center to the outside, a hole 7 for inserting the crankshaft 3 is made, a concave groove 6 is provided on the inner peripheral surface, and the mounting bracket 14 is provided.
An opening 8 is provided in the center of the crank 2 with a fixing plate 5 to be fixed to the frame 13, and an E-shaped lid 9 is attached to the opening 8 with a screw or the like, and the H-shaped movable left and right in the opening 8. The H-shaped stopper 10 is fixed to both ends of the crankshaft 3, and a roller 11 slidably mounted on the inner surface of the groove 6 of the fixed plate 5 is attached. Pedal
12 was attached.

[0006]

According to the present invention, when the rider steps on the drive pedal 12, the drive pedal 12 rotates in the direction from the top dead center to the bottom dead center. At this time, the roller 11 provided on the crank 2 slides along the groove 6 of the fixed plate 5, and the sliding force causes the opening 8 of the crank 2 inserted into the H-shaped stopper 10 to move. The pedal 12 is moved and extended, and as a result of the pedal 12 being strongly depressed toward the bottom dead center in the extended state, the depressing force is increased. It is transmitted to the rear wheels.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. First, as in a normal bicycle 1, a front wheel, a rear wheel, a steering wheel, a saddle, a driving portion, and a frame 13 which integrally forms these components are mainly constituted. And the driving unit is a crank 2
The driving force can be transmitted to the rear wheels via the crank gear 4 and the chain by depressing the pedal 12 at the tip of the vehicle, and the vehicle can travel. In the bicycle 1 having such a configuration, in the crank structure of the bicycle 1 of the present invention, the length of the crank 2 is longer than the standard length and the stepping force is increased from the top dead center to the bottom dead center.

As shown in FIGS. 1 to 3 of the drawings, a fixing plate 5 to be attached to a frame 13 of the bicycle 1 by a mounting bracket 14.
Are installed on the left and right corresponding to both feet of the passenger. Further, the fixing plate 5 is formed in a circular shape larger than the diameter of the crank gear 4, a hole 7 for inserting the crankshaft 3 is opened from the center, and a roller 11 provided on the crank 2 is inserted.
A groove 6 that is rotatably slid is provided on the inner peripheral surface. Thereby, even if the pedal 12 is depressed, the roller 11 slides in the groove 6 and rotates, so that the pedal 12 can be depressed smoothly,
Further, since the fixing plate 5 is attached to three places of the frame 13, it is fixed firmly without moving.

As shown in FIGS. 1 to 4, in the crank structure of the present invention, H-shaped stoppers 10 are fixed to both ends of the crankshaft 3 on the crankshaft 3, and the crank An opening 8 is provided by cutting out the center of the opening, and an E-shaped lid is fixed to a tip of the opening 8 with a screw or the like. Reference numeral 8 denotes an opening, which is inserted into the center of an H-shaped stopper 10 and smoothly moves inside the crank 2 freely left and right by the depressing force of the pedal. Reference numeral 11 denotes a roller 11 that slides inside the groove 6 provided in the fixing plate 5. When the roller 11 slides inside the groove 6, even if the rider steps on the pedal, the roller 11 moves smoothly inside the groove 6 and does not hinder the rotation of the crankshaft 3 without hindering rotation.
Can be rotated. A bearing or the like is attached to the tip of the roller 11 so that the sliding can be smoothly performed.

Thus, when the pedal is depressed, the stopper 10
Rotates in the stepping-in direction, thereby sliding the inside of the opening 8 to move the crank 2, and the roller 11 slides inside the groove 6 of the fixed plate 5, so that the rotation is not hindered. The shaft 3 rotates the crank gear 4 and transmits the driving force to the rear wheels via the chain so that the bicycle 1 runs.

[0011]

According to the bicycle crank structure of the present invention constructed as described above, the length of the crank is longer than the standard length, and the pedal is moved toward the bottom dead center in the extended state. As a result of being strongly depressed, the depressing force is drastically increased, and a large rotational driving force is transmitted to the rear wheel of the bicycle via the crank gear and the chain.

[Brief description of the drawings]

FIG. 1 is a plan view of the present invention.

FIG. 2 is an explanatory diagram showing an operation state of the crank structure of the present invention.

FIG. 3 is a perspective view showing a configuration of a fixing plate of the present invention.

FIG. 4 is a perspective view showing a crank configuration of the present invention.

FIG. 5 is a perspective view showing a catch of a crank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bicycle 2 Crank 3 Crankshaft 4 Gear 5 Fixing plate 6 Groove 7 Hole 8 Opening 9 Lid 10 Clasp 11 Roller 12 Pedal 13 Frame 14 Mounting bracket

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[Procedure amendment]

[Submission date] April 13, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (1)

[Claims] 1. A frame having a diameter larger than that of a gear fixed to a crankshaft, a hole for inserting a crankshaft shifted from a position outside a center portion, a concave groove on an inner peripheral surface, and a mounting bracket. And an opening in the center of the crank, an E-shaped lid is attached to the opening with screws or the like, and an H-shaped stopper that can move freely from side to side is inserted into the opening. A crank structure for a bicycle, characterized in that a U-shaped stopper is fixed to both ends of the crankshaft, a roller slidably and rotatably mounted in a groove of the fixed plate on an inner surface, and a pedal mounted on a tip end. .