WO2000040457A1

WO2000040457A1 - A kit for converting a muscle-powered vehicle into a motor-assisted vehicle

Info

Publication number: WO2000040457A1
Application number: PCT/IL2000/000008
Authority: WO
Inventors: Arie Becker
Original assignee: Bikit Israel Ltd.
Priority date: 1999-01-07
Filing date: 2000-01-04
Publication date: 2000-07-13
Also published as: CN1336883A; IL127961A0; AU1998400A

Abstract

The invention provides a kit for converting a wheeled, tire-equipped, muscle-powered vehicle into a motor-assisted one, including at least one electric motor (9), the shaft of which carries a friction roller (8) for frictionally driving a wheel (12) of the wheeled vehicle; lever means (6), pivotably articulated to a supporting member and fixedly attached to the at least one electric motor (9), the lever means (6) to be used for selectively causing the friction roller (8) to frictionally engage, or become disengaged from, the wheel (12); upper and lower bracket means fixedly and permanently attached to a portion of the vehicle, at least the lower bracket including means facilitating a controlled tilting of the at least one motor (9) to bring the shaft thereof into a radial plane of the wheel (12); wherein the supporting member is insertable into and withdrawable from the upper and lower bracket means, thereby facilitating rapid mounting and dismounting of the at least one electric motor (9).

Description

A KIT FOR CONVERTING A MUSCLE-POWERED VEHICLE INTO A MOTOR-ASSISTED VEHICLE

Field of the Invention

The present invention relates to a kit for converting a muscle-powered vehicle into a motor-assisted one. Background of the Invention

Of the various types of motor-assisted vehicles known, a particularly useful type is described in the present Applicant's U.S. Patent No. 5,735,363. Yet, based on practical experience gathered in the meantime with that vehicle, as well as with other prior art vehicles referred to in Applicant's U.S. Patent 5,078,227, it was felt that in order to maximize the usefulness of such motor-assisted vehicles, particularly motor-assisted bicycles, additional aspects of the utility of such devices had to be given consideration. Summary of the Invention

It is one object of the present invention to provide a kit for converting a muscle-powered vehicle into a motor-assisted one, which would simplify the conversion procedure to such a degree as would also enable persons with limited technical understanding and manual skill to succeed in rapidly and easily converting their bicycles and obtaining safe and fully road-worthy vehicles. Such an endeavor also implies reduction of the number of components, and their complexity, to a minimum.

It is another object of the invention to prevent theft and vandalism by facilitating the rapid detachment of the main components of the drive unit when the bicycle is parked for long periods of time, and their equally rapid reattachment without a need for readjustments of any kind.

It is a further object of the invention to provide means for facilitating the proper initial adjustment of the orientation of the friction rollers of the drive unit relative to the driven wheel, to ensure both minimum wear of the rollers as well as of the tire and maximum efficiency of frictional power transmission. It is a still further object of the invention to provide means for automatically activating the assisting motor when a certain minimum speed has been attained by pedalling.

According to the present invention, the above objects are achieved by providing a kit for converting a wheeled, tire-equipped, muscle-powered vehicle into a motor-assisted one, comprising at least one electric motor, the shaft of which carries a friction roller for frictionally driving a wheel of said wheeled vehicle; lever means, pivotably articulated to a supporting member and fixedly attached to said at least one electric motor, said lever means to be used for selectively causing said friction roller to frictionally engage, or become disengaged from, said wheel; upper and lower bracket means fixedly and permanently attached to a portion of said vehicle, at least said lower bracket comprising means facilitating a controlled tilting of said at least one motor to bring the shaft thereof into a radial plane of said wheel; wherein said supporting member is insertable into, and withdrawable from, said upper and lower bracket means, thereby facilitating rapid mounting and dismounting of said at least one electric motor. Brief Description of the Drawings

The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood.

With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. In the drawings: Fig. 1 is a perspective view of the drive unit in the engaged position; Fig. 2 is a similar view of the drive unit in the disengaged position; Fig. 3 is a perspective view of the drive unit from behind, showing the supporting member and the engagement/disengagement lever as pivotably articulated to the supporting member; Fig. 4 is a perspective view of the drive unit as seen from below; Fig. 5 is a front elevation of the drive unit, illustrating the relation between the rollers and tire; Fig. 6 is a perspective view of the upper bracket and the lower bracket by means of which the drive unit is attached to the front fork stem; Fig. 7 is an exploded view, showing the components of the upper and lower brackets of Fig. 6; Fig. 8 is an enlarged view of the lower bracket with the drive unit in position; Figs. 9 to 11 illustrate the procedure whereby the proper height position of the drive unit is attained relative to the tire; Fig. 12 illustrates the procedure whereby the motor shafts are brought into a radial plane of the bicycle wheel, and Fig. 13 illustrates the location of a magnetic sensor that monitors the pedalling rate. Detailed Description of Preferred Embodiments

Referring now to the drawings, there is seen in Fig. 1 a drive unit 2 assembled from the kit according to the invention and mounted on the front fork stem 4, 4- of a common bicycle. Unit 2 is shown in the engaged position, with engagement/disengagement lever 6 pushed forward into a first limit position and friction rollers 8 mounted on shafts of electric motors 9 straddling tire 10 and making frictional contact with either flank of tire 10, thereby generating a tangential force that produces a torque on wheel 12, assisting in pedalling. Rollers 8 are advantageously made of a synthetic rubber of a suitable plastic material. The cross-section of the rollers is designed to at least partly fit that of a bicycle tire, to obtain a large area of contact while not resisting their disengagement when not in use.

Details of unit 2 and its components will be discussed further below and in conjunction with the drawings showing them to better advantage and to a larger scale.

Fig. 2 represents drive unit 2 in the disengaged position, with lever 6 pulled backward into a second limit position and rollers 8 swung away from, and thus no longer making contact with, tire 10.

Fig. 3 is a perspective rear view of unit 2, showing supporting member 14 to which lever 6 is articulated by means of pivot member 16. Further seen are an upper clamp 18 and a lower clamp 18-j , which not only provide supporting member 14 with rigidity and stability, but also, as will be shown further below, are instrumental in attaching unit 2 to the bicycle. Also seen is a base 20 fixedly connected to the lower ends of lever 6 and to which are attached electric motors 9. Further shown is a gate element 22 into which lever 6 is introduced and which retains lever 6 in the disengaged position shown in Fig. 3. Also shown is a notched lug 24 integral with the lower faces of motors 9, the significance and use of which will become apparent further below.

Fig. 4 is a perspective view of unit 2 as seen from below, showing the way in which motors 9 are attached to base 20. Each motor is provided with bolts 24, for which elongated holes (not shown) are provided in base 20. Similar holes are also provided for motor shafts 26. Due to this arrangement, the distance between motor shafts 26, i.e., between rollers 8, can be adjusted to fit tire 10, as shown by way of example in Fig. 5 (e.g., 40 and 42 mm, respectively). Plates 28 and nuts 30 permit the required distance to be fixedly set.

Fig. 6 is a perspective view of upper bracket 32 and lower bracket 34, whereby unit 2 is attached to front fork stem 4, 4-| . Upper bracket 32 also includes a lock, comprising a lock housing 36 and a U-bolt 38 which, when inserted into housing 36 as shown, prevents the unauthorized disconnection of unit 2. Key 40 can be removed only when U-bolt 38 is pushed into housing 36. The handlebar, connected to stem 4, is not shown.

Fig. 7 is an exploded view of upper and lower brackets 32 and 34. Upper bracket 32 is seen to consist of two clamp halves 42, 42-| , which are clamped onto stem portion 4 by means of screws 44 via lock housing plate 46. Hanger plate 48 is then affixed to clamp half 42, using countersunk screws 50. Lower bracket 34 consists of a threaded bolt 52 that passes through a bore 54 in stem portion 4-| and carries a rubber buffer 56 at its front end. As seen in Fig. 8, rubber buffer 56 serves as a stop for, and defines the position of, unit 2, the significance of which position will be discussed further below.

Also threaded onto bolt 52 is a guide washer 58 having an annular groove 60 into which fit, fork-like, the ends of supporting member 14 (Fig. 3). Guide washer 58 provides supporting member 14 with one degree of freedom in translation and one degree of freedom in rotation. For aesthetic reasons, the free part of bolt 52 is covered by a plastic bellows 62 (Fig. 8).

Figs. 9 to 11 illustrate the way in which the proper height position of unit 2 is attained relative to tire 10 during the initial mounting of unit 2. With U-bolt 38 removed from lock housing 36 and lever 6 in the disengaged position, unit 2 is introduced into hanger plate 48 in the direction of arrow A (Fig. 9), while the lower ends of supporting member 14 are slipped into groove 60 of guide washer 58. At this stage, clamps 18, 18— | , while in position, are not clamped tight.

Fig. 10 shows the next stage. Lever 6 is brought into the engaged position and, by pulling or pushing supporting member 14 while holding upper clamp 18 in its position inside hanger plate 48, motors 9 can be moved in the direction of double arrow B until rollers 8 are in the proper position relative to tire 10, as indicated in Fig. 11. Then upper clamp 18 is clamped tight. Lower clamp 18-( should now be slid to a position where a small gap a (=2-3 mm) is left between clamp 18-| and guide member To prevent excessive wear of friction rollers 8 and the flanks of tire 10, the force applied by rollers 8 on tire 10 must be purely tangential. This condition, can only be fulfilled when shafts 26 (Fig. 5) are located in a radial plane of wheel 12, i.e., a plane which passes through the center of wheel 12. To adjust the position of motors 9 and rollers 8 accordingly, the kit according to the invention provides a slender steel rod 64 (Fig. 12), one end of which fits a duct (not shown) in an ornamental bead 66 in the upper part of the upper motor housing. Further below, it passes through the notch in the above-mentioned notched lug 24 (Fig. 3), thereby being retained in a plane also containing shafts 26 of motors 9. The other end of rod 64 extends at least to the axle of wheel 12. By opening nuts 68 and 70, lower bracket 18-j can be advanced or withdrawn until motors 9 come to rest against buffer 56 and rod 64 points exactly to the center of the axle of wheel 12, after which nuts 68 and 70 are again tightened and rod 64 is removed. If, after this procedure, the descending portion of supporting member 14 is no longer parallel with front fork stem 4, parallelism can be restored by opening nut 72 and rotating threaded guide washer 58 (Fig. 8) in the required direction.

The kit according to the present invention optionally also provides a magnetic sensor that monitors the pedalling rate and automatically switches on unit 2 after a speed of about 5 km/h has been attained solely by pedalling, and increases motor speed as the pedalling rate increases.

The magnetic sensor (Fig. 13) comprises a permanent magnet 74 strapped to one of the pedal cranks and a proximity sensor 76 fixedly attached to the bottom fork of the bicycle. The signal produced when magnet 74 passes in proximity to sensor 76 is led, via a cable 78, to a housing 80 mounted on down tube 82 of the bicycle and accommodating a microprocessor for motor control as well as a 2 x 12N rechargeable battery, each of a capacity of 7.2 Ah. Housing 80 is lockable to the bicycle frame and is rapidly and easily detached to prevent theft.

Further provided is a booster button attached to the handlebar, the pressing of which provides an immediate increase of motor speed. It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. A kit for converting a wheeled, tire-equipped, muscle-powered vehicle into a motor-assisted one, comprising: at least one electric motor, the shaft of which carries a friction roller for frictionally driving a wheel of said wheeled vehicle; lever means, pivotably articulated to a supporting member and fixedly attached to said at least one electric motor, said lever means to be used for selectively causing said friction roller to frictionally engage, or become disengaged from, said wheel; upper and lower bracket means fixedly and permanently attached to a portion of said vehicle, at least said lower bracket comprising means facilitating a controlled tilting of said at least one motor to bring the shaft thereof into a radial plane of said wheel; wherein said supporting member is insertable into and withdrawable from said upper and lower bracket means, thereby facilitating rapid mounting and dismounting of said at least one electric motor.

2. The kit as claimed in claim 1, wherein said kit comprises two electric motors, the shaft of each of which carries a friction roller.

3. The kit as claimed in claim 2, wherein said pivotable lever means has two limit positions, in the first of which positions said two rollers straddle and frictionally engage the tire of said wheel, and in the second of which positions said rollers are swung away and are thus disengaged from said tire.

4. The kit as claimed in claim 2, further comprising means to adjust and set the distance between said two rollers.

5. The kit as claimed in claim 1, wherein said lower bracket means comprises guide means that provides said supporting means with one degree of freedom in translation and one degree of freedom in rotation.

6. The kit as claimed in claim 5, wherein said guide means is movable along said lower bracket means for correction of lack of parallelism between a descending portion of said supporting means and the axis of said front fork stem.

7. The kit as claimed in claim 1, further comprising a slender rod temporarily attachable to the outside of one of said motors in such a way as to extend in a plane containing the roller-carrying shaft of said motor , said rod being used to indicate whether said shafts in the engaged position of said rollers are located in a radial plane of said wheel.

8. The kit as claimed in claim 1, wherein said vehicle is a bicycle, further comprising sensor means for monitoring the pedalling rate of said bicycle.

9. The kit as claimed in claim 8, wherein said sensor means includes a permanent magnet fixedly attached to one of the pedal cranks of said bicycle and a proximity sensor fixedly attached to the bottom fork of said bicycle.