AU707518B2 - Folding bicycle - Google Patents

Abstract

The proposal is for a folding bicycle in which the frame is reduced to a single member extending between the steering bearing (2) and the chainwheel bearing (7) and on which is hinged an arm (9) for the rear wheel to which the crank mechanism (6) is fitted and which can be pivoted forwards in the region of the front wheel (4) about the chain wheel bearing (7).

Description

-2- In another conventional bicycle (EP-PS 0 103 609), which is only suitable for small wheel diameters, the frame consists essentially of three shell-shaped portions of which one portion supports the crank mechanism and rear wheel, another the saddle and a third the bearing for the front wheel steering. For folding together, these three portions are pivoted and folded together about an axis, the saddle bar and the handle bars are pushed in, and the two wheels folded up.

Although the final volume of the folding bicycle is extremely small in the folded together state, this is achieved only with a significant degree of technical difficulty. In addition, the plurality of pivoting axes have destabilizing effects not to mention the fact that the front axle of the folding bicycle is overloaded by the rider during use.

In another conventional folding bicycle requiring extremely small wheel diameters (DE-OS 43 13 832), the rotation axis of the rear wheel arm does not extend parallel to that of the crank mechanism and of the rear wheel so that each pivoting of the rear wheel arm triggers a steering motion of the rear wheel. For this reason, this folding bicycle allows only small amounts of resilient motion (less than 20 mm). In addition, each pivoting motion of the rear wheel arm leads to a change in the separation between the pedal bearing and the rear wheel axle and thereby to a changing chain tension, which can only partially be compensated for 20 by the spring located in the gearing mechanism.

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:In another conventional folding bicycle (DE-OS 44 00 500), two ways are described for folding together the bicycle, the bicycle having a frame with a resiliently borne rear wheel. The rear wheel is either removed, the rear construction released and pivoted in an upward direction so that the arms seat in proximity to the saddle support, or the saddle support subdivided so that it can accept the rear wheel when the rear wheel arm is folded in the upper direction.

9I ~Both alternatives have the common feature that the volume of the bicycle in the folded together state is not substantially less than in the folded out state. The S.first variation is also user unfriendly, whereas the second variation is extremely 30 difficult to manufacture.

9 10/5/99b19757.spec,-2a- -2a- In accordance with the present invention, therefore, there is provided a folding bicycle including a front wheel adapted to be steered by handle bars or the like means, a rear wheel which is adapted to be driven by a crank mechanism, and a saddle, said bicycle further including: a frame having at one end thereof a bearing means for said crank mechanism and, at the other end thereof, a bearing means for said front wheel, said bearing means for said front wheel having an axis of rotation transverse to that of said bearing means of said crank mechanism; a saddle support means connected to said frame; a support member supporting said rear wheel and connecting said rear wheel to said frame at a position removed from said crank mechanism and with a pivot bearing means on said frame about the rotation axis on which said support member is adapted to be pivoted with said rear wheel for folding, wherein said frame directly connects said bearing means for said front wheel and said pivot bearing, said crank mechanism is disposed in said support member which, in turn, is configured as a one or two pronged arm, said rotation axis for said pivot bearing means is disposed outside of the rotation axis of said crank mechanism and wherein, after folding together, said support member and said rear wheel are disposed in proximity to or within the region of said front wheel.

The folding bicycle in accordance with the invention the advantage of S 20 having a volume in the folded together state, even when using normal wheel diameters (26 inches or 28 inches), whose diameter is only slightly larger than the diameter of the rear or front wheel. In addition, the folding mechanism is extremely simple to effect so that this folding bicycle is more economical to manufacture. Not least of all, the construction in accordance with the invention facilitates an extremely aesthetic shape with a minimum amount of effort required for folding together the bicycle, in particular without the danger of soiling the hands. Particularly advantageous is that only one frame with one longitudinal extension is required. Connection between mutually adjacent frame components, required with the conventional folding bicycles and leading to additional difficulty, 30 expense and 10/5/99b19757.spec,-2adisadvantage is, with the invention, advantageously not required an therefore not present. It is important for compact folding that the pivoting bearing of the support structure bearing the rear wheel be close to the rotational axis of the crank mechanism to thereby ensure that, after the folding together procedure, the rear wheel axle is approximately at the height of the front wheel axle or that the rear wheel occupies the volume in which the front wheel was previously located. If required, the front wheel can be removed and disposed adjacent thereto. Integration of the crank mechanism into the arm results in a constant separation between the rotation axis of the crank mechanism and the rear axle, as a result of which, the chain guide and tensioning are not influenced by the folding procedure and the rear wheel arm, in particular for embodiments having double arms, is stiffened.

In accordance with an advantageous embodiment of the invention, the rotation axis of the pivot bearing is parallel to that of the crank mechanism. In this manner, when folding together, the support member and the back wheel are pivoted from the back towards the front in the plane of the bicycle, wherein the pivot range can be in excess of 180 o. Since the support member functions as the arm on which the back wheel is disposed and is not, as is the case in prior art, a frame structure having triangular construction to connect the back wheel receptacle, the pedal bearing and the saddle clamp, no additional interfering frame member is present after pivoting in the rear wheel. The entire portion behind the pivot bearing can be folded away.

In accordance with an additional advantageous embodiment of the invention, the rotation axis for the pivot bearing of the rear wheel arm is disposed in proximity to the crank mechanism so that the volume in the folded together state is small and, in the event of a resiliently borne real wheel, the normally undesirable self-stiffening of the rear wheel suspension when pedalling in the standing position can be nearly completely avoided.

In an additional advantageous embodiment of the invention, the pivot path of the wheel arm in the folding-out direction, e.g. in the operating state of the folding bicycle, is limited by a stop disposed between the frame and the wheel arm. The forces which act on the rear wheel and on the wheel arm during bicycling are advantageously directed towards the stop so that an advantageous interlocking is present without additional locking mechanisms. In one conventional folding bicycle (EP-PS 0 103 609), it is e.g. necessary to support the entire load with one locking mechanism by means of which the arm, which is part of the frame, is locked relative to another frame portion.

In accordance with an additional advantageous embodiment of the invention, the stop is resilient. Such a spring-loading can be effected by a gas suspension using a cartridge, with a spring shock absorbing element, using a rubber-metal construction, or with an elastomer foam.

In accordance with an additional advantageous embodiment of the invention, the stop can be adjusted to change the pivot path. In this manner, the clearance between the ground and the crank mechanism can also be changed, which is e.g. advantageous for applications involving mountain bikes.

In accordance with an additional advantageous embodiment of the invention, at least one of the end pivot positions of the wheel arm can be locked, which could be possible for both the pivoted-in as well as the pivoted-out state.

In accordance with an additional alternative embodiment of the invention, the rotation axis of the pivot bearing is substantially vertical in the operating state of the folding bicycle, wherein the frame and the support portions in proximity to the crank mechanism are connected in the plane extending perpendicular to the rotation axis, wherein a device is provided for on the rotation axis bearing which locks and releases the two components. Such a per se conventional configuration of the rotation axis (EP-OS 0 129 164) has, in the folding bicycle in accordance with the invention, the advantage that the rear wheel can be folded in without the saddle, since same is no longer connected to the arm.

In accordance with an additional advantageous configuration of the invention, which can also be used in and of itself, the saddle support is a saddle arm which is pivotivably borne at one end on the frame and which supports the saddle at its other end. Such an arm can be pivoted in dependence on the configuration of its pivot bearing such that the seat can be pivoted in the upward or in the downward direction depending on which embodiment has a smaller final volume.

In accordance with an additional advantageous configuration of the invention, the operating position of the saddle arm is limited by a stop. Depending on the kind of pivot bearing, the saddle arm is pushed onto the stop when the saddle is loaded or a locking mechanism is required to hold the saddle arm on the stop during use.

In accordance with an additional advantageous embodiment of the invention, the saddle arm is resilient relative to the frame. It is however also possible to configure the saddle arm to be intrinsically elastic and resilient. In cooperation with the 7us p uspension of the rear wheel arm, an optimum shock absorber system can thereby be fashioned for uneven terrain or rough streets without compromising the dynamic stability of the bicycle.

In accordance with an additional advantageous configuration of the invention, the saddle arm, following unlocking, can be pivoted for folding toward the rear wheel (downward). This normally has the smallest final volume.

Additional advantages and advantageous embodiments of the invention can be extracted from the subsequent description, the drawing and the claims.

Drawing Two embodiments of the object of the invention are represented in the drawings and are more closely described below.

Figure 1 shows a folding bicycle in the folded out condition, figures 2 and 3 in an intermediate folding position, figure 4 in the folded in position and figures 5 and 6 show the second embodiment in the intermediate folded position.

In the first embodiment shown in figures 1 through 4, the fork 3 of a front wheel 4 is disposed on a frame 1 (manufactured as a contoured component) via a rotation bearing 2. The front wheel 4 can be steered by means of a handlebars 5. A crank mechanism 6 having a rotation bearing 7 is disposed on the lower end of the frame 1 to drive the rear wheel 8, borne on the end of a wheel arm 9, in a conventional fashion. The wheel arm 9 is pivotably borne on the frame 1 at its other end via a pivot bearing 10 mounted in proximity to the rotation bearing 7, wherein the rotation axis of rotation bearing 7 and pivot bearing 10 are parallel to each other. The rotation axis of the pivot bearing 2 is, however, disposed on frame 1 perpendicular to that of rotation axis 7. Clearly, frames and wheel arms can also be effected using tubular construction. The saddle arm 11 is hinged to the frame with a pivot bearing 12 in the region between the rotation bearings 2 and 7. The saddle 13 is mounted to the free end of the saddle arm 11. In this folded out state, the folding bicycle in accordance with the invention is superficially similar to the conventional bicycle except for the fact that, due to the low number of constructional components forming the frame, one has the impression of an extremely light vehicle. The above mentioned substantial differences in accordance with the invention nevertheless obtain.

RZ4 The step by step folding in of the bicycle is described in figures 2 and 3. In figure 2, the front wheel 4 is removed from the fork 3 and the rear wheel 8 with the wheel arm 9 is shown pivoted approximately 90 0 out of the original position in accordance with arrow I as rotated about the pivot bearing 10. In figure 3, the rear wheel 8 along with the wheel arm 9 is then pivoted to such a degree that it approximately assumes the original position of the front wheel 4. It is thereby pivoted into the open fork 3 of the front wheel.

Figure 4 shows the folding bicycle in the folded together state in which, in accordance with arrow II, the saddle arm 11 having saddle 13 has then been pivoted up to the frame 1 about the pivot bearing 12.

The folded-together bicycle shown in figure 4 can be easily stored in the trunk of an automobile or packed into a portable bag. In order to unfold the bicycle, a reverse sequence is performed initially with the saddle arm 11 and then the rear wheel 8 being folded back before the front wheel 4 is replaced.

In the second embodiment shown in figure 5, the same components are given the same reference symbols with only changed or new components given progressive reference symbols. The frame 14 is, in this embodiment, connected in a plane 15 to support member 9 for pivoting about a rotation axis 18. A device for holding together and releasing the two components 9 and 14 is not described in greater detail. For folding in, the back wheel 8 is pivoted about the rotation axis 18 in accordance with arrow III out of the operation position shown in figure 1 and into the position shown in figure 6 after loosening the lock. Both the front wheel 4 and the rear wheel 8 are then nearly parallel to each other. In this embodiment, it is not necessary to remove the front wheel 4 for folding up the bicycle. Finally, the saddle arm 11 is also folded up in correspondence with arrow IV to complete folding together of the bicycle. The pivot bearing 12 can be disposed along the entire region between the rotation bearing 2 and the pivot bearing 10 to effect the desired size of access opening. If the pivot bearing 12 is disposed in proximity to the pivot bearing 10, the seat arm 11 can be folding towards the rear wheel 8 after the rear wheel 8 is already located in proximity to the front wheel 4 in the folded together state so that the saddle arm 11 approaches the rotation bearing 2 when folded in.

All the features represented in the description, the following claims and, the drawing can be important to the invention individually or collectively in arbitrary combination.

List of Reference Symbols 1 Frame 2 Rotation bearing 3 Fork 4 Front wheel Handle bars 6 Crank mechanism 7 Rotation bearing 8 Rear wheel 9 Rear wheel arm Pivot bearing for wheel real arm 11 Saddle arm 12 Pivot bearing for saddle arm 13 Saddle 14 Frame Separation plane 16 17 18 Rotation axis

1. A folding bicycle including a front wheel adapted to be steered by handle bars or the like means, a rear wheel which is adapted to be driven by a crank mechanism, and a saddle, said bicycle further including: a frame having at one end thereof a bearing means for said crank mechanism and, at the other end thereof, a bearing means for said front wheel, said bearing means for said front wheel having an axis of rotation transverse to that of said bearing means of said crank mechanism; a saddle support means connected to said frame; a support member supporting said rear wheel and connecting said rear wheel to said frame at a position removed from said crank mechanism and with a pivot bearing means on said frame about the rotation axis on which said support member is adapted to be pivoted with said rear wheel for folding, wherein said frame directly connects said bearing means for said front wheel and said pivot bearing, said crank mechanism is disposed in said support member which, in turn, is configured as a one or two pronged arm, said rotation axis for said pivot bearing means is disposed outside of the rotation axis of said crank mechanism and wherein, after folding together, said support member and said rear wheel are disposed in proximity to or within the region of said front wheel.

2. The folding bicycle according to Claim 1, wherein said rotation axis 20 of said pivot bearing means is parallel to that of said crank mechanism.

3. The folding bicycle according to Claim 2, wherein said rotation axis of said pivot bearing means is displaced towards said front wheel and/or in a downward direction.

4. The folding bicycle according to any one of the preceding claims, wherein said axis of rotation of said pivot bearing means is proximate to said crank mechanism.

5. The folding bicycle according to any one of the preceding claims, wherein the pivot path of a wheel arm in the folding out direction is limited by a .stop means disposed between said frame and said wheel arm.

30 6. The folding bicycle according to Claim 5, wherein said stop means is resilient.

10/5/99bl9757.spec,-8a-

Claims (6)

1. 7. The folding bicycle according to Claim 6, wherein said stop means is adapted to be adjusted to change the pivot path.
2. 8. The folding bicycle according to any one of Claims 5 to 7, wherein at least one of the end pivot positions of said wheel arm is adapted to be locked.
3. 9. The folding bicycle according to Claim 1, wherein the rotation axis of said pivot bearing means extends substantially vertically in the operating state of said folding bicycle, and wherein said frame and said support member are connected together in a plane perpendicular to said rotation axis and near said crank mechanism, by means of a lockable rotation axis bearing means, and wherein means are disposed on said rotation axis bearing means for holding together and unlocking these two components. The folding bicycle according to any one of the preceding claims, wherein said saddle support means is a saddle arm which is hinged at one side in a pivotable fashion to said frame and which supports said saddle at the other side.
4. 11. The folding bicycle according to Claim 10, wherein the operating position of said saddle arm is limited by a stop means.
5. 12. The folding bicycle according to Claim 10 or Claim 11, wherein said saddle arm is resilient relative to said frame. 20 13. The folding bicycle according to Claim 12, wherein said saddle arm is adapted to be pivoted, following unlocking, for folding in the direction of said rear wheel.
6. 14. A folding bicycle, substantially as described herein with reference to the accompanying. DATED this 7 th day of May 1999. DENYS F. HACKERT By his Patent Attorneys 30 CALLINAN LAWRIE 10/5/99b19757.spec,-9a- Abstract A folding bicycle is proposed in which the frame is reduced to a single member extending between the steering bearing and the chain wheel bearing and on which an arm is hinged for the real wheel to which the crank mechanism is fitted and which can be pivoted forwards into the region of the front wheel about the rotation axis of rotation bearing Fig. 1