IL90644A - Auxiliary electric powered drive for vehicle - Google Patents

Description

AUXILIARY ELECTRIC POWERED DRIVE FOR VEHICLE S.A.E. AFIKIM C:07617 076l7sae.bic 1-662 16.6. 1989 FIELD OF THE INVENTION The present invention relates to electrically driven vehicles and more particularly to retrof ttable electrically driven auxiliary drives for vehicles which are normally manually propelled.

BACKGROUND OF THE INVENTION Various types of auxiliary drives for vehicles such as bicycles are known in the patent literature. Representative of the art are the following patents: U.S. Patent 1 , 259.989 describes a gasoline engine driven auxiliary drive which includes two driven rollers which engage opposite sides of the rim of the back wheel of a bicycle.

U.S. Patent 2 , 031 , 881 describes a motor bicycle including a gasoline engine driven roller which engages the outer surface of the back tire of the bicycle.

U.S. Patent 2 , 069 , 679 describes a gasoline engine driven auxiliary drive which includes a geared member which engages a suitably configured tooth containing tire tread of a bicycle.

U.S. Patent 3 339 · 59 describes a powered friction-driving device for vehicles including a pair of frusto-conical rollers which simultaneously engage the vehicle wheel. Speed shifting apparatus is provided for altering the point or line of engagement of the drive members with the tire such that the speed of the wheel may be changed for a given speed of rotation of the drive members .

U.S. Patent 3.891,044 provides a cone shaped electric motor driven friction drive which engages an auxiliary rim associated with the front wheel of a bicycle.

U.S. Patent 3.915.250 describes an auxiliary drive for a bicycle employing a pair of rollers which pinch the back time of a bicycle therebetween.

U.S. Patent 4,143,730 describes an electric motor driven friction drive which engages the outer surface of the back tire of a bicycle.

SUMMARY OF THE INVENTION The present invention seeks to provide an electrically driven auxiliary drive for vehicles such as bicycles and wheelchairs, which is relatively light, inexpensive and convenient to use.

There is thus provided in accordance with a preferred embodiment of the present invention an electrically driven auxiliary drive for vehicles including first and second electric motors each having associated therewith a friction drive element and apparatus for selectably bringing the friction drive elements into operative driving engagement with both the rim and the tire of a vehicle wheel for driving thereof.

Additionally in accordance with an embodiment of the invention there is provided an auxiliary drive for vehicles including first and second electric motors each having associated therewith a friction drive element, apparatus for selectably bringing the friction drive elements into operative driving engagement with a vehicle wheel for driving thereof and motor control apparatus for operating the electric motors including apparatus preventing motor operation when the friction drive elements are not in operative driving engagement with the vehicle wheel .

Additionally in accordance with an embodiment of the invention there is provided an auxiliary drive for vehicles including first and second electric motors each having associated therewith a friction drive element, apparatus for mounting the first and second electric motors about a single pivot point, and apparatus for selectably pivoting the first and second electric motors about the single pivot point, thus selectively bringing the friction drive elements into operative driving engagement with a vehicle wheel for driving thereof, whereby due to the pivot mounting of the first and second motors, the first and second motors can maintain driving engagement with the vehicle wheel notwithstanding eccentricities thereof.

Further in accordance with a preferred embodiment of the invention there is provided an electrically driven auxiliary drive and regenerative braking system for vehicles including first and second electric motors each having associated therewith a friction drive element, apparatus for selectably bringing the friction drive elements into operative driving engagement with a vehicle wheel for driving thereof in a driving mode of operation, and for being driven thereby in a regenerative braking mode of operation and electrical energy storage apparatus for supplying electrical power to the first and second electric motors during operation in the driving mode and for receiving electrical power from the first and second electric motors during operation in the regenerative braking mode of operation.

In accordance with a preferred embodiment of the invention, the electrically driven auxiliary drive and regenerative braking system for vehicles includes electrical switching apparatus for preventing overturning due to excessive braking.

Further in accordance with a preferred embodiment of the invention, there is provided an electrically driven auxiliary drive for vehicles including first and second electric motors each having associated therewith a friction drive element, apparatus for selectably bringing the friction drive elements into operative driving engagement with a vehicle wheel for driving thereof and electrical energy storage apparatus for supplying electrical power to the first and second electric motors, wherein the electrical energy storage apparatus is readily removed from the auxiliary drive for recharging at a remote location.

Further in accordance with a preferred embodiment of the invention, the electrical energy storage apparatus is integrally formed with apparatus for permitting recharging thereof from mains power.

Additionally in accordance with a preferred embodiment of the invention the first and second electric motors are pivotably mounted onto a bicycle frame adjacent the front wheel so as to selectably assume either a wheel engagement orientation or a disengaged orientation and there is provided a spring loaded lever for determining the orientation of the first and second electric motors . The spring loaded lever is operative to normally maintain the first and second electric motors in a disengaged orientation, except when a predetermined force is applied to the lever.

Further in accordance with a preferred embodiment of the invention the first and second electric motors are pivotably mounted onto a bicycle frame adjacent the front wheel so as to selectably assume either a wheel engagement orientation or a disengaged orientation and there is provided a manually operated lever for determining the orientation of the first and second electric motors. The manually operated lever is operative to normally maintain the first and second electric motors in a disengaged orientation, except when a predetermined force is applied to the lever.

Additionally in accordance with an embodiment of the invention, the electrical energy storage apparatus is removably mounted on a base formed with electrical contacts arranged for immediate quick contact with corresponding contacts on the electrical energy storage apparatus when the electrical energy storage apparatus is positioned thereon.

According to an alternative embodiment of the present invention, the electrically driven auxiliary drive may be operatively associated with at least one and preferably two wheels of a wheelchair.

Further in accordance with an embodiment of the invention there is provided selectably operable dynamic braking apparatus which operates by short circuiting the terminals of each of the first and second motors. In order to prevent excessive braking which could cause overturning or excessive equipment wear, preferably the dynamic braking apparatus operates to short circuit the terminals in a pulsed mode. The dynamic braking apparatus may be associated with any of the embodiments of the present invention.

Additionally in accordance with a preferred embodiment of the present invention, the apparatus for selectively bringing the friction drive elements into operative driving engagement with a vehicle wheel includes apparatus for maintaining a predetermined pressure engagement between the friction drive elements and the vehicle wheel.

Further in accordance with a preferred embodiment of the invention, a front light and turn signals may be associated with the electrical energy storage apparatus and mounted thereon. Hazard warning light operation may be provided. A DC electrical socket may be provided for operation of auxiliary equipment, such as audio equipment.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS The present invention will be core fully understood and appreciated from the following detailed description, taken in conjunction with the drawings in which: Figs. 1A and IB are pictorial illustrations of auxiliary drive apparatus constructed and operative in accordance with a preferred embodiment of the present invention in respective engaged and disengaged orientations; Figs. 2A and 2B are pictorial illustrations of auxiliary drive apparatus constructed and operative in accordance with another preferred embodiment of the present invention in respective disengaged and engaged orientations; Figs. 3A and 3B are pictorial illustrations of auxiliary drive apparatus constructed and operative in accordance with yet another preferred embodiment of the present invention in respective engaged and disengaged orientations; Fig. 4 is a pictorial illustration of auxiliary drive apparatus constructed and operative in accordance with an alternative embodiment of the invention mounted onto a wheelchair; Figs. 5 and 6 are respective back and top view illustrations of the apparatus of Fig. 4; and Fig. 7 is a pictorial illustration of an alternative embodiment of the apparatus of Fig. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Figs. 1A and IB which illustrate auxiliary drive apparatus constructed and operative in accordance with a preferred embodiment of the present invention, associated with a bicycle. In the illustrated embodiment first and second electric motors 10 and 12 are pivotably mounted by means of mounting brackets 14 and 16 respectively onto a pivot location 17 fixed with respect to the top part 18 of the fork 19 of the bicycle. Location 17 may be identical to the location onto which the front fender is mounted in many bicycles.

As seen in the illustrations, mounting brackets 14 and 16 engage respective motors 10 and 12 adjacent the lower portions thereof.

There are also provided mounting brackets 20 and 22 which engage the electric motors 10 and 12 respectively adjacent the upper portions thereof. The mounting brackets 20 and 22 are pivotably mounted onto respective intermediate linkages 24 and 26 which are in turn mounted onto an electric motor 28 , whose output shaft is fixedly attached to a screw shaft 30. Screw shaft 30 engages a fixed nut 32 which is fixedly mounted onto the top part 18 of the fork 19 , such that operation of the motor causes the motor to move either up or down along an axis defined by the screw shaft 30.

According to an alternative embodiment of the present invention, the motor 28 may be replaced by a manually operable device for selectably displacing the intermediate linkages 24 and 26 , as illustrated in Figs. 2A, 2B, 3A and 3B and described - hereinbelow.

Motors 10 and 12 each include a drive shaft 3^ onto which is mounted a friction driving element 36 , typically formed of a high friction rubber or plastic material.

Fig. 1A illustrates the auxiliary drive apparatus oriented in a drive engagement orientation wherein the motor 28 is positioned to cause intermediate linkages 24 and 26 to define.a maximum spread between respective mounting brackets 20 and 22. In this orientation, due to the pivot mounting of the motors about pivot location 17 , maximum spreading of the top portions of the motors 1G and 12 causes the friction driving elements 6 of the respective motors 10 and 12 to be urged together in friction driving engagement with the vehicle wheel. Apparatus is preferably provided for maintaining the engagement force between the friction driving elements 36 and the wheel within a given range for maximum driving efficiency and minimum wear.

It is a particular feature of the present invention that the friction driving elements 3 preferably engage both a portion of the rim 39 and a portion of the tire *J0 , for enhanced driving efficiency.

It is also a particular feature of the present invention that the first and second motors 10 and 12 pivot about a single pivot point 17. As a result, should the bicycle wheel be eccentric, the motors 10 and 12 can follow the wheel in the pivot plane .

Fig. IB illustrates the orientation of motors 10 and 12 in a disengaged orientation wherein the friction drive elements 36 are out of contact with the wheel.

Mounted on top part 18 of fork 19 is a quick coupling base element 42 which is formed with a plurality of electrical contacts 44 and is arranged to receive and support a portable rechargeable electrical energy source 46. Energy source 46 typically comprises a conventional rechargeable battery 48 and a conventional battery charger 0 which can operate on mains current. Energy source 46 is provided with a pair of electrical contacts 52 which are arranged to establish electrical contact with contacts 44 when the energy source 46 is seated on base element 42.

Base element 42 is provided with pivotable retaining clips 5 for removably retaining energy source 46 onto base element 42. It is a particular feature of the present invention that energy source 46 is readily removed from base element 42 by a user, and may be so removed at will for recharging, simply by pivoting clips 54 out of engaging relationship with the energy source 46.

In accordance with a preferred embodiment of the present invention at least one or both regenerative braking and dynamic braking may be provided. Regenerative braking may be provided relatively simply by allowing motion of the vehicle wheel to drive the electric motors as generator, thereby recharging the electrical energy source 46, while slowing down the vehicle wheel Selectably operable dynamic braking may be provided by short circuiting the terminals of each of the first and second motors . In order to prevent excessive braking which could cause overturning or excessive equipment wear, preferably the dynamic braking apparatus operates to short circuit the terminals " in a pulsed mode. The regenerative and dynamic braking apparatus may be associated with any of the embodiments of the present invention.

According to a preferred embodiment of the present invention there is provided, preferably inside base element 2, electrical control circuitry 56 for governing the operation of the motors 10 and 12. The electrical control circuitry may be entirely conventional and well within the knowledge of a person of ordinary skill in the art in view of the disclosure herein. A manually operated control array 58, including control actuator buttons 59. 60 and 61, is provided on a handlebar 62 and communicates with the electrical control circuitry 5 via a cable 63· Typically button 59 may be employed to cause engagement of the auxiliary drive apparatus with a wheel, while button 60 may be used to actuate forward driving and regenerative braking and button 6l may be used to provide dynamic braking respectively.

Reference is now made to Figs. 2A and 2B which is similar to the embodiment of Figs . 1A and IB where motor 28 and associated screw shaft 30 is replaced by a manually operated spring arrangement 70 which normally urges motors 10 and 12 towards a non wheel engagement orientation as seen in Fig. 2A. Driving engagement of the auxiliary drive apparatus is provided by an operator depressing an operating lever 72, such as a lever of the type commonly employed as a handbrake actuator, thereby pulling on a cable 7^ , which extends from lever 72 over a roller 76, typically mounted on the handlebar 62, and raising a linkage 78. to define a maximum spread between respective mounting brackets 20 and 22 on respective motors 10 and 12, producing friction driving engagement between friction driving elements 36 and the vehicle wheel. Suitable means (not shown) may be provided for selectably locking lever 12 in the orientation illustrated in Fig. 2B.

A switch 79 is provided to sense full depression of lever 72, indicating full frictional driving engagement between elements 36 and the vehicle wheel. In accordance with a preferred, embodiment of the invention, this indication is required before electrical power is provided to motors 10 and 12, in order to prevent undue wear of elements 36.

Reference is now made to Figs. 3A and 3B which is similar to the embodiment of Figs. 2A and 2B, wherein the handbrake type actuator lever 7 is replaced by a manually actuable, vertically displaceable screw arrangement 80, formed with a operator engageable vertical push knob 82. Depression of knob 82 causes a screw 84 to move downwardly and rotate relative to a fixed nut 86 mounted on handlebar 62. Downward movement of screw 84 causes intermediate linkages 24 to define a maximum spread between respective mounting brackets 20 and 22 on respective motors 10 and 12, producing friction driving engagement between friction driving elements 3 and the vehicle wheel. Suitable means (not shown) may be provided for selectably locking screw 84 in the orientation illustrated in Fig. 3B- A switch 88 is provided to sense full depression of knob 82, indicating full frictional driving engagement between elements 36 and the vehicle wheel. In accordance with a preferred embodiment of the invention, this indication is required before electrical power is provided to motors 10 and 12, in order to prevent undue wear of elements 36.

Reference is now made to Figs. 4, 5 and 6 which illustrate a wheelchair which is fitted with an electrical auxiliary drive 89 on each of its two back wheels. The wheelchair is typically controlled by an operator via a joy-stick 90, via suitable control circuitry (not shown) which provides power to the electrical auxiliary drive associated with each wheel in accordance with the desired direction and speed of travel in accordance with conventional techniques. The structure and operation of the auxiliary drive may be as described hereinabove in connection with any one or combination of Figs. 1A - 3Β· Reference is now made to Fig. 7. which illustrates additional features which may be associated with the present invention. Fig. 7 is essentially similar to Fig. IB but also illustrates the following additional elements: Mounted on energy source 46 may be a front headlight 100, turn signal lights 102, and a turn signal indicator switch 104, all of which may draw power from the power source 46 and operate in a conventional manner. Battery status indicator lights 106 may be provided on the power source 46.

A hazard warning light actuator 108 may produce pulsed operation of headlight 100 and turn signal lights 102. A DC power outlet 110 may provide auxiliary DC power for various devices, such as audio equipment (not shown) . An electrical mains power connector 112 may be provided for connecting the recharger 50 . appreciated that any or all of the apparatus illustrated in Fig. 7 may be incorporated in any of the embodiments illustrated in Figs. 1A - 6.

It will be apparent to persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined only by the claims which follow:

Claims (18)

90644/3 C L A I M S

1. An auxiliary drive for vehicles comprising: first and second electric motors each having associated therewith a friction drive element; means for selectably bringing the friction drive elements into operative driving engagement with a vehicle wheel having a rotation axis, for driving thereof, including means for pivoting said first and second motors about an axis parallel to the rotation axis.

2. An auxiliary drive for vehicles comprising: first and second electric motors each having associated therewith a friction drive element; means for mounting the first and second electric motors about a single pivot axis; means for selectably pivoting the first and second electric motors about the single pivot axis, thus selectively bringing the friction drive elements into operative driving engagement with a vehicle wheel having a rotation axis parallel to the pivot axis for driving of the vehicle wheel, and wherein said means for mounting said first and second electric motors includes means for permitting limited motion of said first and second electric motors in a plane parallel to said pivot axis and said rotation axis thereby to enable said first and second motors to maintain driving engagement with the vehicle wheel notwithstanding eccentricities thereof.

3. An electrically driven auxiliary drive and regenerative braking system for vehicles comprising: 90644/3 first and second electric motors each having associated therewith a friction drive element; means for selectably bringing the friction drive elements into operative driving engagement with a vehicle wheel having a rotation axis for driving of the vehicle wheel in a driving mode of operation, by pivoting the friction drive about a pivot axis parallel to the rotation axis, and for being driven thereby in a regenerative braking mode of operation; and electrical energy storage means for supplying electrical power to the first and second electric motors during operation in the driving mode and for receiving electrical power from the first and second electric motors during operation in the regenerative braking mode of operation.

4. A system according to claim 3 and also comprising: electrical switching means for preventing overturning due to excessive braking.

5. Apparatus according to claim 3 and wherein said electrical energy storage means is integrally formed with means for permitting recharging thereof from mains power.

6. Apparatus according to claim 1 and wherein said first and second electric motors are pivotably mounted so as to selectably assume either a wheel engagement orientation or a disengaged orientation and wherein said means for selectably bringing the friction drive elements into operative driving engagement with a vehicle wheel comprises a spring loaded lever for determining the orientation of the first and second electric motors, said spring loaded lever being operative to normally maintain the first and second electric motors in a disengaged 90644/3 orientation, except when a predetermined force is applied to the lever .

7. Apparatus according to claim 1 and wherein said first and second electric motors are pivotably mounted so as to selectably assume either a wheel engagement orientation or a disengaged orientation and wherein said means for selectively bringing the friction drive elements into operative driving engagement with a vehicle wheel comprises a manually operated lever for determining the orientation of the first and second electric motors, said manually operated lever being operative to normally maintain the first and second electric motors in a disengaged orientation, except when a predetermined force is applied to the lever.

8. Apparatus according to any of claims 3-5 and also comprising a base member for receiving and supporting said electrical energy storage means, said base member being formed with electrical contacts arranged for immediate quick contact with corresponding contacts on the electrical energy storage apparatus when the electrical energy storage apparatus is positioned thereon.

9. Apparatus according to any of the preceding claims and being associated with the front wheel of a bicycle.

10. Apparatus according to any of claims 1-8 and being associated with each of two rear wheels of a wheelchair.

11. Apparatus according to any of claims 1-8 and being associated with only one of the two rear wheels of a wheelchair. 90644/3

12. A bicycle comprising a frame and front and rear wheels and auxiliary drive means according to any of claims 1 - 8.

13. A wheelchair comprising a seat and at least two rear wheels and auxiliary drive means according to any of claims 1 - 8 associated with each of said at least two rear wheels.

14. A wheelchair comprising a seat and at least two rear wheels and auxiliary drive means according to any of claims 1 - 8 associated with only one of the at least two rear wheels.

15. Apparatus according to claim 1 and wherein said means for selectively bringing comprises means for maintaining a predetermined pressure engagement between the friction drive elements and the vehicle wheel.

16. Apparatus according to any of claims 3-5 and also comprising a front light and turn signals associated with the electrical energy storage apparatus and mounted thereon.

17. Apparatus according to any of claims 3-5 and also comprising means for providing hazard warning light operation.

18. Apparatus according to any of claims 3-5 and also comprising a DC electrical socket mounted on said electrical energy storage apparatus. For the Applicant, isanford T. Colb & Co. C: 07617