JPH0744941U - Bicycle crank - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a crank that can travel according to the leg force by adjusting the length of the crank without using a transmission gear. According to the present invention, a base portion of a circular arc plate portion 3 is connected and pivoted to a tip of a crank body 1 whose base end is connected to a rotary shaft 2 of a bicycle A. A mechanism for freely fastening the circular arc plate portion 3 at an arbitrary angle by a fastening member 8 screwed into a screw hole 7 on the surface of the crank body 1 located in the long hole 6 is provided. Pedal 1
It is a bicycle crank with 0 attached.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bicycle crank whose length can be adjusted according to slopes or leg strength.

[0002]

[Prior art]

 Conventionally, a bicycle has a pedal mounted on the tip of a crank orbitally driven by a leg force to drive and rotate a gear mounted on a rotation shaft of a crank base, and a gear for transmission connected between the gear and a rear wheel shaft. By rotating the chain, the rear wheels are driven to rotate and run. Therefore, in the case of an uphill road, a mechanism is used to reduce the load force applied to the crank base by the transmission gear.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned speed change gear, as the load is reduced, many cranks must be rotated, and in addition, many bicycles are equipped with a speed change gear for sports such as cycling. Currently, it is not installed. For this reason, people with weak leg strength, such as old people and women, often put an excessive load on their feet even when running on flat ground. In order to solve the above problems, the present invention aims to provide a bicycle crank in which the load can be easily adjusted according to the lever principle by freely expanding and contracting the length of the crank. .

[0004]

[Means for Solving the Problems]

 The above object of the present invention can be achieved by a crank having the following structure. That is, the purpose is to pivotally connect the middle part of the fan-shaped arc plate part to the tip of the crank body whose base end is connected to the rotating shaft of the bicycle so as to be rotatable left and right. A fastening member that has a long hole penetrating along it, a screw hole is bored in the surface of the crank body located in the long hole, and the arc plate portion and the crank body are freely fastened in the screw hole at an arbitrary angle. The bicycle crank is characterized in that a pedal is rotatably attached to the tip of the arc plate portion.

[0005]

[Action]

 In the bicycle crank of the present invention, as shown in FIG. 3, the distance between the central axis of the pedal 10 mounted on the tip of the arc plate 3 and the rotary shaft 2 to which the crank body 1 is directly connected is calculated from the maximum distance length. As indicated by the imaginary line in the figure, the fastening member 8 is loosened and the circular arc plate portion 3 is rotated along the elongated hole 6 to reduce the distance between the central axis of the pedal 10 and the rotary shaft 2. Is what you can do. Therefore, by adjusting the crank length according to the leg strength of the person, the load on the rotary shaft 2 can be reduced by the lever principle.

[0006]

【Example】

 Hereinafter, a bicycle crank according to the present invention will be described in detail with reference to the drawings showing an embodiment thereof. FIG. 1 is an explanatory view showing an embodiment of the present invention. Reference numeral 1 denotes a crank body directly connected to a rotating shaft 2 of a bicycle A. At the tip of the crank body 1, a midway portion of a fan-shaped arc plate portion 3 is connected to the left and right by a connecting pivot pin member 4 such as a bolt. It is connected in a rotatable state. A circular arc-shaped long hole 6 is formed in front of the peripheral edge portion 5 of the circular arc plate portion 3, and as shown in FIG. 2, a screw hole 7 is formed in the surface of the crank body 1 in the long hole 6. A fastening member 8 such as a bolt is screwed into the threaded hole 7 through the elongated hole 6, and a washer 9 previously inserted into the fastening member 8 causes the arc plate portion 3 to be connected to the crank body 1. The mechanism is sandwiched and fixed between them. A pedal 10 is rotatably attached to the tip of the arc plate portion 3.

[0007]

[Effect of device]

 As described above, according to the present invention, by adjusting the crank length according to the leg force, flat traveling or traveling on a slope can be performed without any trouble. Furthermore, it has various advantages such as the fact that only the cranks need to be replaced with existing bicycles, which is easy and cheap.

[0008]

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a crank of the present invention.

FIG. 2 is an enlarged cross-sectional explanatory view of a main part of the present invention.

FIG. 3 is an explanatory view of the operation of the present invention.

[Explanation of symbols]

 1 Crank Main Body 2 Rotating Shaft 3 Arc Plate 5 Peripheral 6 Long Hole 7 Screw Hole 8 Fastening Member 10 Pedal

Claims (1)

[Scope of utility model registration request] 1. A front end of a crank body whose base end is connected to a rotating shaft of a bicycle is pivotally connected to a middle portion of a fan-shaped arc plate part so as to be rotatable left and right, and a peripheral part of the arc plate part is in front of the peripheral part. Along with a long hole, a screw hole is bored in the crank body surface located in the long hole, and a fastening member for freely fastening the arc plate portion and the crank body at an arbitrary angle in the screw hole is provided. A bicycle crank characterized in that the pedal is rotatably attached to the front end of the arc plate portion by screwing.