JPH11129965A - Variable crank shaft position type bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a set position of a crank shaft adjustable and to improve the safety in carrying, by forming a crank shaft holding part and a frame with the independent structural bodies, and slidably or removably mounting the connections thereof on one or more areas to make the crank shaft set position variable. SOLUTION: A mount part 3 is extended from a crank shaft holding part 1, the slots 4 are formed thereon, a frame 2 is provided with the mount holes 7, and both of the slots 4 and the mount holes 7 are separatably fixed by the attaching bolts 5 and the attaching nuts 6. In a case when a set position of a crank shaft 8 is adjusted corresponding to the conformation of body of a rider, the attaching bolts 5 and the attaching nuts 6 are loosened to be slided in the slots 4, and fastened again after the position is adjusted. Further to prevent the crank part from projecting from the other part in a state that a bicycle is folded, the attaching bolts 5 and the attaching nuts 6 are temporarily removed, the crank part 9 and a chain are moved to an upper part of a rear wheel, and the attaching bolts 5 and the attaching nuts 6 are attached from an upper side of the frame 2. Whereby the bicycle can be compactly folded without projections in a safe state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear wheel drive two-wheeled bicycle.

[0002]

2. Description of the Related Art A conventional bicycle has an integral structure in which a crankshaft holding portion and a frame are fixedly connected.

[0003]

Therefore, in the conventional bicycle, the position of the crankshaft cannot be adjusted according to the physique of the occupant, and in the case of a folding bicycle, the circumstance between the rear wheel and the frame in the folded state. Since the crank portion protrudes from the wire, the contractibility is poor, and the protruding object is a chain or a chain gear, which is not preferable in terms of safety.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a bicycle capable of adjusting a setting position of a crankshaft according to a physique of an occupant, and a folding bicycle which is compact in a folded state and has excellent safety in carrying. The purpose is to provide.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a crankshaft holding portion and a frame which are separate and independent structures, and their connection is slidably or detachably connected. One or several places,
The crankshaft set position is variable.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. FIG. 2 is a cross-sectional view from the crankshaft portion of FIG. 1 to a joint portion with a frame. FIG. 3 shows the folded state of the first embodiment. FIG. 4 shows a second embodiment. FIG. 5 is a cross-sectional view of the rear wheel axle portion of FIG. 4 and its vicinity, and FIG. 6 is a cross-sectional view from the crankshaft portion of FIG. FIG. 7 shows a third embodiment. FIG. 8 is a cross-sectional view from the crankshaft portion of FIG. 7 to the joint portion with the frame.

First, the first embodiment will be described. The crankshaft holding portion 1 and the frame 2 are separate and independent structures, and can be separated. Attachment part 3 to crankshaft holding part 1
Are provided with elongated holes 4, while the frame 2 is provided with mounting holes 7. The mounting portion 3 extending from the crankshaft holding portion 1 is fixed to a mounting hole 7 of the frame 2 with a mounting bolt 5 and a mounting nut 6. When adjusting the setting position of the crankshaft 8 according to the occupant's physique, the mounting bolt 5 and the mounting nut 6 are loosened and the elongated hole 4 is slid to adjust the position and re-fixed.

[0008] Also, when the bicycle is folded, the crank 9
In order not to protrude from other parts, the mounting bolts 5 and the mounting nuts 6 connecting the crankshaft holding portion 1 and the frame 2 are once removed, and the crank portion 9 and the chain 10 are moved above the rear wheel 11. Move and attach from above frame 2. As a result, the projection of the chain 10 and the chain gear 19 from the external tangent line 13 between the rear wheel 11, the saddle 12, and the frame 2 is eliminated, and the storage state is compact and the folding state is safe for carrying.

Next, a second embodiment will be described. An arm 14 and a link 15 are connected to the crankshaft holding portion 1 variably with the crankshaft holding portion 1 as a break point. The other end of the arm 14 is rotatably mounted on an arm mounting portion 18 near the rear wheel axle 16, while the link 15 is arranged so as to support the force in the rotational direction of the arm 14 and
Are fixed to the mounting holes 7 with mounting bolts 5 and mounting nuts 6. In addition to the mounting hole 7, the frame 2 has mounting holes 7a and 7b.
The setting position of the crankshaft 8 is adjusted by changing the fixed position of the link 15 to 7a or 7b. In this case, since the arm 14 is provided, the movement of the crankshaft 8 during the adjustment of the crankshaft position is controlled by the arm 14.
Of the chain 10
Operation is simplified by preventing sagging.

The third embodiment differs from the second embodiment in that the mounting point of the arm 14 is coaxial with the rear wheel axle 16 and fastened together with the rear wheel 11 and the link 15 is provided with a length adjusting portion 17. It is. Since the mounting point of the arm 14 is coaxial with the rear wheel shaft 16, the tension of the chain 10 is kept constant regardless of the rotation angle of the arm 14. The figure shows a state in which the crankshaft holding portion 1 is moved to the rear of the rear wheel 11 around the rear wheel axle 16 and fixed to the mounting hole 7c. . The position of the crankshaft 8 is adjusted by the adjusting bolt 2 of the length adjusting portion 17 of the link 15.
The position is adjusted to a position suitable for the occupant's physique by loosening the adjustment portion nut 21 and changing the length to zero.

The above embodiment is only one example of the application of the present invention, and the details are arranged and applied based on the above example, such as replacing the bolt and nut screwing method of each part with a one-touch method. Is the subject of the present invention.

[0012]

As is apparent from the above description, the present invention has the following effects.

The crankshaft holding portion 1 and the frame 2 are formed as separate structures, and the connection between them is slidable or detachable, and the connecting portion is provided at one or several places, so that it can be adapted to the size of the occupant. The setting position of the crankshaft 8 can be adjusted.

Further, the folding bicycle can be brought into a folded state in which the chain 10 and the chain gear 19 do not protrude from the external tangent line 13 between the rear wheel 11, the saddle 12, and the frame 2, and are compact and can be stored and carried safely.

By providing an arm 14 rotatably mounted near the rear wheel axle 16 and connecting the arm 14 to the crankshaft holding portion 1, the slack of the chain 10 can be prevented and the operation of adjusting the crankshaft position can be simplified. In particular, when the mounting point of the arm 14 is made coincident with the rear wheel axle 16, the rotation angle of the arm 14 can be increased because the tension of the chain 10 is kept constant, and the crankshaft 8 is moved rearward of the rear wheel 11. You can also move and ride in a prone position.

[Brief description of the drawings]

FIG. 1 is a side view of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view from a crankshaft portion of FIG. 1 to a coupling portion with a frame.

FIG. 3 is a side view of the first embodiment in a folded state.

FIG. 4 is a side view of a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of the rear wheel shaft portion and the arm mounting portion of FIG.

FIG. 6 is a cross-sectional view from a crankshaft portion of FIG. 4 to a coupling portion with a frame.

FIG. 7 is a side view of a third embodiment of the present invention.

8 is a cross-sectional view from a crankshaft portion of FIG. 7 to a connection portion with a frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Crankshaft holding part 2 ... Frame 3 ... Mounting part 4 ... Elongated hole 5 ... Mounting bolt 6 ... Mounting nut 7, 7a, 7b, 7c ... Mounting hole 8 ... Crankshaft 9 ... Crank part 10 ... Chain 11 ... Rear wheel DESCRIPTION OF SYMBOLS 12 ... Saddle 13 ... External tangent line 14 ... Arm 15 ... Link 16 ... Rear wheel axle 17 ... Length adjustment part 18 ... Arm mounting part 19 ... Chain gear 20 ... Adjustment part bolt 21 ... Adjustment part nut

Claims (2)

[Claims] 1. A crankshaft holding portion and a frame are formed as separate independent structures, and their connection is slidably or detachably connected. One or several connecting portions are provided to set a crankshaft at a set position. Bicycle characterized by being variable. 2. In the above, an arm rotatably mounted on or near the rear wheel axle is provided, and the arm and the crankshaft holding portion are connected to each other, and the crankshaft set position is set on the circumference of the center of the mounting point of the arm. 2. The bicycle according to claim 1, wherein