JP2009143339A - Folding bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light folding bicycle capable of adjusting a clearance between a handle bar and a seat for a rider and excellent in handling. <P>SOLUTION: The bicycle 1 foldable between a front wheel 2 and a rear wheel 3 is provided with a support body 7 having a shaft 7a erected vertically and a sprocket displacement mechanism for holding a drive sprocket 6 so as to enable displacement in the front/rear direction; a main frame 8 long in the front/rear direction and having a front part for holding the front wheel 2 and a lower face with a fitting part relatively rotatably fitted to an upper end of the shaft 7a; a seat pipe 9 having a lower end fixed to the support body 7 swingably in the front/rear direction; a stay 10 fixed to the support body 7 and holding the rear wheel 3; and a lock mechanism for fixing an angle of the seat pipe 9 with respect to the main frame 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bicycle that can be folded between a front wheel and a rear wheel when the user does not get on.

In general, a folding bicycle is equipped with a tire having a small diameter of 20 inches or less in order to minimize the occupied volume during storage and achieve weight reduction.
On the other hand, folding bicycles are also required that can adjust the distance between the handle and the seat according to the physique of the rider. In addition, there is a demand for a handle that can adjust the distance depending on the type of handle. For example, in the case of a drop handle, since the brake lever is attached at a position protruding forward, it is easier to ride the seat closer to the handle than in the case of a straight handle.
As a bicycle capable of adjusting the distance between the steering wheel and the seat, a bicycle is known in which a main frame spanned between front and rear wheels is divided into a front wheel side and a rear wheel side and is slidable (Patent Document 1, And Patent Document 2). A folding bicycle that employs this method is also commercially available (Non-Patent Document 1).

JP 2003-246290 A JP2004-142718 Charaway Callaway.com Main Store-Bicycle mail order TOP >> General information >> Vehicles >> Folding bicycle-http: //www.charaway.com/info/005syubetu/010/nyi.Html (November 30, 2007) )

However, folding bicycles tend to be inherently unstable due to their small diameter tires. If the main frame is slid and extended in order to increase the distance between the handle and the seat, the load applied to the front wheels will become lighter, and this will become increasingly unstable.
In addition, in the case of the slide type, it is necessary to secure a certain length for the coupling between the front wheel side frame and the rear wheel side frame in addition to the distance adjustable distance, so that the loss of the members is large and the entire amount is correspondingly increased. It also increases the weight and goes against the folding bike concept.
Therefore, an object of the present invention is to provide a lightweight folding bicycle that can adjust the distance between the handle and the seat in accordance with the rider and is excellent in handling.

In order to solve the problem, the folding bicycle of the present invention is
A support body having a shaft standing in a vertical direction and a sprocket displacement mechanism that holds the drive sprocket so as to be displaceable in the front-rear direction;
A main frame having a fitting portion that is long in the front-rear direction, holds the front wheel at the front portion, and is fitted on the lower surface so as to be relatively rotatable with the upper end of the shaft;
A seat pipe having a lower end fixed to the support so as to be swingable in the front-rear direction;
A stay fixed to the support and holding a rear wheel;
And a lock mechanism for fixing an angle of the seat pipe with respect to the main frame.

  When the bicycle is folded, the lock between the main frame and the seat pipe is released, and the seat pipe is tilted backward. Then, rotate the main frame around the shaft to match the front and rear wheels. When boarding, the main frame is reversed and deployed, the seat pipe is erected, and the seat pipe is fixed to the main frame by a lock mechanism at an angle at which the seat and the handle are at an appropriate interval. Then, the drive sprocket is moved so as to match the position of the seat and fixed at an appropriate position. If the rider is the same, the seat pipe can be quickly fixed by setting it with a limiter so that the distance between the seat and the handle is not narrower than the seat pipe angle determined at the first ride. . Further, if the drive sprocket is also fixed at a position determined at the time of the first boarding, it is not necessary to be displaced unless the rider changes.

  According to this bicycle, the distance between the handle and the seat can be adjusted by simply changing the angle of the seat pipe. Therefore, there is little loss of members. Moreover, the relative positional relationship between the support body and the main frame in which the rider's weight is applied via the seat pipe is constant during deployment. For this reason, the load applied to the front wheels is substantially constant regardless of the distance between the handle and the seat.

  The distance between the steering wheel and the seat can be adjusted according to the rider, and the weight of the front wheel is almost constant because the weight of the front wheel is almost constant because the loss of members is small.

Embodiment 1
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing the unfolded state of the folding bicycle according to the first embodiment, FIG. 2 is a front view showing the seat post in the unfolded state, and FIG. 3A shows the folded state. A front view and FIG. 3B are plan views of the same.

The bicycle 1 includes a front wheel 2, a rear wheel 3, a handle 4, a seat 5, a drive sprocket 6, a driven sprocket (not shown), a support 7, a main frame 8, a seat pipe 9 and a stay 10. Among these, the front wheel 2, the rear wheel 3, the seat 5, the drive sprocket 6 and the driven sprocket may be of a known shape.
The support body 7 is guided by a cylindrical shaft 7a standing vertically, a joint 7b extending rearward from the vicinity of the upper end of the shaft 7a, a rail 7c extending horizontally rearward from the vicinity of the lower end of the shaft 7a, and the rail 7c. It has a bracket 7d that can be displaced in the direction. A hinge pin 7f is attached to the joint 7b. The bracket 7d has a U-shape that opens downward so as to straddle the rail 7c in a cross-sectional view orthogonal to the rail 7c (FIG. 4), and holds the rotating shaft of the drive sprocket 6 via a bearing under the rail 7c. is doing. Then, the bolt 7e screwed to the bracket 7d is rotated and pressed against the upper surface of the rail 7c, thereby preventing the bracket 7d from moving relative to the rail 7c.

  The main frame 8 is long in the front-rear direction, and a head pipe 8a is welded to the front end, and a fitting member 8b is fitted to the lower surface near the rear end so as to be relatively rotatable with the upper end of the shaft 7a. A known quick release type fastening tool 8d capable of adjusting the inner diameter is attached to the lower end of the fitting member 8b. A front fork 8c that holds the front wheel from both sides is attached to the lower end of the head pipe 8a so as to be rotatable about its own axis. A post 4a of the handle 4 is attached to the upper end of the head pipe 8a. One end of a biaxial hinge 4b whose rotational axes are parallel to each other is fixed to the inner peripheral surface near the lower end of the post 4a (FIG. 5). The other end of the biaxial hinge 4b has a cross-shaped cross section in which plates having a width equal to the inner diameter of the head pipe 8a are combined (FIG. 6). The biaxial hinge 4b is inserted into the head pipe 8a when unfolded (FIG. 5A), and is pulled out so that only the other end remains in the head pipe 8a when folded, and the post 4a can be bent together with the handle 4. (FIG. 5B). A connecting pipe 4c that can also surround the upper end of the head pipe 8a is welded to the outer peripheral surface of the lower end of the post 4a. The connecting pipe 4c is formed with slits 4d in the axial direction on one side, and flanges 4e are welded so as to protrude in the radial direction on both sides of the slit 4d. A single bolt 4f passes through the two flanges 4e, and the interval between the flanges 4e increases and decreases with the screw motion of a nut (not shown) screwed into the bolt 4f, and the width and connection of the slit 4d. The diameter of the tube 4c can be changed.

  The seat pipe 9 has a lower end hinged to the joint 7b so as to be swingable in the front-rear direction, and two connecting plates 9a capable of sandwiching the rear portion of the main frame 8 from both sides are welded to the front surface. A bolt 9b is passed through the connecting plate 9a in a direction orthogonal to the main frame 8, and a nut (not shown) is screwed to the tip of the bolt 9b. An arc-shaped groove is formed on the rear end surface of the main frame 8 along a circumferential line centering on a fulcrum of the seat pipe 9, that is, a hinge pin connecting the seat pipe 9 and the joint 7b, and having a radius reaching the bolt 9b. 8c is formed. A seat 5 post is inserted into the upper end of the seat pipe 9.

The stay 10 is provided on each side of the rear wheel and has a V-shape. One side 10a, also called a seat stay, is welded to the joint 7b, and the other side, also called a chain stay, is welded to the rail 7c. The rotating shaft of the rear wheel 3 is held.
When the bicycle 1 is folded, the bolt 4f is loosened, the handle 4 is pulled up to bend the post 4a, the bolt 9b is loosened, the seat pipe 9 is tilted backward, and the fastening tool 8d is loosened around the shaft 7a. The main frame 8 is rotated and the front wheel 2 and the rear wheel 3 are aligned. When riding, the main frame 8 is reversed and deployed, and the handle 4 is raised to lower the biaxial hinge 4b into the head pipe 8a. The position of the handle 4 is fixed by tightening the bolt 4f, the tightening tool 8d is tightened, the seat pipe 9 is erected, the rear portion of the main frame 8 is sandwiched between the connecting plates 9a, and the seat 5 and the handle 4 are at an appropriate distance The seat pipe 9 is fixed to the main frame 8 by tightening the bolts 9b. Then, the drive sprocket 6 is moved to an appropriate position and fixed with bolts 7e. If the rider is the same, the bolt 7e may remain tightened even when folded.

According to the bicycle 1, the distance between the handle 4 and the seat 5 can be adjusted only by changing the angle of the seat pipe 9. Therefore, there is little loss of a member and it is lightweight. Moreover, the relative positional relationship between the support body 7 and the main frame 8 in which the rider's weight is applied via the seat pipe 9 is constant during deployment. For this reason, regardless of the distance between the handle 4 and the seat 5, the load applied to the front wheel 2 is substantially constant, and the handle operation is stabilized.
Note that a known quick release structure may be applied to the bolt 4f and the bolt 9b in order to speed up the expansion and folding operations.

Embodiment 2
In this embodiment, the locking mechanism between the seat pipe and the main frame is further improved. FIG. 7 is a front view showing a lock mechanism applied to the bicycle according to the second embodiment. Since it may be the same as that of the first embodiment except for the lock mechanism, the description is omitted.
In this embodiment, a horizontally long groove 18c is formed at the rear portion of the main frame 8, and a short groove 18d descending from the rear toward the front is formed below the groove 18c. On the other hand, the connecting plate 9a is provided with a groove 19b that intersects the groove 18c substantially orthogonal to the groove 18c when the seat pipe 9 stands and a groove 19c that has a gentler slope than the groove 18d. Bolts 19d and 19e are passed through the groove 19b and the groove 19c, respectively. The hinge pin hole 17g of the joint 7b is a long hole whose major axis is substantially the same as the length of the groove 18d and rises from the front to the rear.

  According to the bicycle of this embodiment, when riding, the seat pipe 9 is raised and at the same time the seat pipe 9 is pulled up by the amount of play of the hinge pin hole 17g, and the bolts 19d and 19e are slid within the grooves 18c and 18c. Tighten in position. Since the angle of the seat pipe 9 is determined by the position of the bolt 19e with respect to the groove 19c, it is not necessary to loosen the bolt 19e at the time of folding unless the rider changes. Just pull it up and knock it back. That is, the bolt 19e serves as a limiter for the swing motion of the seat pipe 9.

It is a front view which shows the unfolding state of the folding bicycle which concerns on Embodiment 1. FIG. It is a front view which shows the place which fell the seat post back in the unfolded state. (A) is a front view which shows a folded state, (b) is the top view. (A) is an enlarged front view which shows a sprocket displacement mechanism, (b) is the same vertical direction sectional drawing. (A) is the front sectional view in the unfolding state which shows the coupling | bond part of a handle post and a head pipe, (b) is a front sectional view in the same folding state. (A) is an axial sectional view showing the main part of the handle post, (b) is an axial sectional view orthogonal to the section of (a). It is a front view which shows the locking mechanism of the main frame of the folding bicycle which concerns on Embodiment 1, and a seat pipe.

Explanation of symbols

1 Bicycle 2 Front Wheel 3 Rear Wheel 4 Handle 5 Seat 6 Drive Sprocket 7 Support 8 Main Frame 9 Seatpost 10 Stay

Claims (5)

In a bicycle that can be folded between the front and rear wheels,
A support body having a shaft standing in a vertical direction and a sprocket displacement mechanism that holds the drive sprocket so as to be displaceable in the front-rear direction;
A main frame having a fitting portion that is long in the front-rear direction, holds the front wheel at the front portion, and is fitted on the lower surface so as to be relatively rotatable with the upper end of the shaft;
A seat pipe having a lower end fixed to the support so as to be swingable in the front-rear direction;
A stay fixed to the support and holding a rear wheel;
A folding bicycle comprising a lock mechanism for fixing an angle of a seat pipe with respect to a main frame.   2. The bicycle according to claim 1, wherein the sprocket displacement mechanism includes a rail horizontally extending rearward from near the lower end of the shaft, and a bracket guided by the rail and capable of being displaced in the front-rear direction and rotatably holding the drive sprocket.   The support has a joint near the rear wheel near the upper end of the shaft, and the lower end of the seat pipe is hinged to the joint so that the seat pipe is fixed to be swingable in the front-rear direction. 3. The bicycle according to claim 2, comprising a seat stay spanned between the joint and the rear wheel, and a chain stay spanned between the rail and the rear wheel.   The lock mechanism is attached to one of the rear part of the main frame and the seat pipe along a circular arc centered on the fulcrum of the seat pipe, and attached to a position on the other arc on the other side, along with the rotation of the seat pipe. The bicycle according to claim 1, comprising a bolt that relatively moves in the groove and a nut that is screwed into the bolt.   The locking mechanism includes a first slit formed substantially horizontally at the rear of the main frame, a second slit formed in the seat pipe so as to intersect the first slit when the seat pipe stands, and both slits. The bicycle according to claim 1, comprising a bolt penetrating through the crossing position of the nut and a nut screw-fitted to the bolt.

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