GB2349441A

GB2349441A - Apparatus for transmitting power to vehicle drive means

Info

Publication number: GB2349441A
Application number: GB9909632A
Authority: GB
Inventors: Christopher Ralph Evans
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-04-28
Filing date: 1999-04-28
Publication date: 2000-11-01
Anticipated expiration: 2019-04-28
Also published as: GB9909632D0; GB2349441B

Abstract

An apparatus for connecting a source of motive power to a vehicle drive means comprises elongate members (1, 2) pivotally attached to a support frame (3). Pivotal movement of the members (1, 2) is about shaft members (4, 5) which together comprise a split-shaft. The uppermost end of each member (1, 2) is connected to a piston assembly (18, 19 respectively). Reciprocal movement of the piston assemblies (18, 19) effects complementary pivotal movement of the elongate members (1, 2) which, in use, engage a belt (25). Movement of the belt (25) in response to the movement of the elongate members (1, 2) results in movement of wheels (22, 23) which are engaged by the belt (25).

Description

APPARATUS FOR TRANSMITTING POWER TO VEHICLE DRIVE MEANS The invention relates to apparatus for transmitting power to vehicle drive means, the apparatus being adapted in use to connect operatively a source of motive power to a flywheel, typically for a clutch. The invention relates more specifically to, but is not intended to be limited to, apparatus for operatively connecting a combustion engine of a vehicle to a clutch flywheel, which in turn drives at least one wheel of the vehicle.

Such apparatus is known in the form of transmissions which include a crank (or cam) and flywheel arrangement in which the flywheel is rotated by connecting rods extending from the extremities of the engine pistons.

This apparatus requires a plurality of specially-constructed parts and a relatively large amount of space is required for the apparatus to be included in a vehicle drive system.

The applicant has devised an apparatus which is relatively compact in size compared to the prior art, and which has fewer components, thereby decreasing the chances of mechanical failure. The apparatus can include non-metallic components to improve efficiency and reduce the mass of the apparatus.

In a first aspect, the present invention provides an apparatus adapted in use to connect operatively a source of motive power to a vehicle drive means, in which the apparatus comprises at least two elongate members each having input and output connection parts, each elongate member being pivotally attached to a support frame at a point along the length of each elongate member between said input and output connection parts, the pivoting of each elongate member being driven in consecutive drive cycles by output from the source of motive power wherein one half of each drive cycle consists of the first elongate member being pivoted from a first angular position relative to the support frame to a second angular position relative to the support frame while the second elongate member is pivoted from said second angular position to said first angular position relative to the support frame, the second elongate member being pivoted in a plane substantially parallel to the first elongate member and spaced therefrom, and the other half of each drive cycle consists of the elongate members being returned simultaneously to each of their respective previous angular positions, and output means operatively connected to the output connection part of each elongate member, the output means being adapted to convert the consecutive half cycles into a continuous rotary movement suitable for driving a clutch flywheel.

Each elongate member therefore undergoes a pendulum-like swing during each half-cycle.

Suitably, the output of the source of motive power comprises at least one piston moveable in a bore, said at least one piston being operatively connected to the input connection part of each elongate member to pivot or swing the elongate member about pivot means provided on the support frame. Preferably, two pistons power the pivoting of each elongate member, one piston extending from the bore during one half cycle, then retracting into the bore during the subsequent half cycle, the other piston, disposed opposite to the first piston, extending and retracting in its bore in the opposite sense to the first piston, so that the pistons work cooperatively to swing the elongate member between the two angular positions.

The pivot means preferably comprises a split-shaft having two parallel, axially-offset members and extending transversely across the support frame. One of the shaft members allows pivoting of the first elongate member relative to the support frame, the second shaft member allowing pivoting of the other elongate member relative to the support frame.

The shaft members locate in bores provided in the support frame.

Preferably, each shaft member rotates axially in its bore during the pivoting of its associated elongate member.

Preferably, the split-shaft has an integrated gear mechanism which allows synchronisation of the movement of the elongate members during each half cycle.

Preferably, the lengths of the two shaft members are such that a part of one shaft member lies adjacent a part of the other shaft member when the split-shaft is attached across the support frame.

For example, a toothed cog (such as a gear) may be fitted to that part of each shaft member which lies adjacent the other shaft member, so that the teeth of one cog engage the teeth of the other cog. This ensures that the swing of one elongate member is synchronised with the opposite swing of the other elongate member, and hence helps to maintain the integrity of each half cycle.

Preferably, the pivot means is located and rotates in an eccentric or elongate bore provided in each elongate member in order to allow vertical displacement of each elongate member relative to the support frame. The vertical displacement allows the source of motive power output and the support frame to be fixed relative to each other, avoiding the need for vertical displacement of the input connection part on the elongate member relative to the support frame during the swing of the elongate member.

The output means preferably comprises a flexible member which attaches to the output connection part of each elongate member, and which includes a loop portion extending between the elongate members. The loop portion, under tension, engages and rotates at least one wheel or other rotatable member. The wheel rotates in one direction during one half-cycle, and rotates in the opposite direction during the following halfcycle. Suitably, ratchet means are provided to convert the alternate rotations into a continuous rotation in a single direction.

The flexible member may be endless and may be, for example, a belt, chain, or cable of a suitable plastics or metallic material. The endless flexible member may, in use, rotate more than one wheel or rotatable member, preferably two wheels or rotatable members.

The flexible member is attached to the output connection part of each elongate member, preferably by means of a float adjustment. In this arrangement, the belt attachment can slide along the length of the elongate member during the swing of each elongate member, allowing the output means to be fixed relative to the support frame. The eccentric or elongate bore for the pivot means and the float attachment of the flexible member to the elongate member avoids the need for vertical displacements of the connection points.

The float adjustment may comprise a slide attached to and moveable relative to the length of the elongate member. The slide ensures a good operative connection between the flexible member and the elongate member, but allows for any vertical displacement of the elongate member relative to the support frame during use.

Alternatively, each elongate member may include a substantially semicircular, toothed portion proximal to the output connection part, the toothed portion being adapted to engage complementary recesses on the flexible member to drive the flexible member when it is under tension during each half-cycle.

In a second aspect, the present invention provides a transport vehicle comprising a vehicle body and a plurality of wheels, and including apparatus in accordance with the first aspect of the invention, wherein the flywheel is adapted to drive at least one of the wheels.

The vehicle may be any suitable vehicle such as a tram, bus or passenger car. The wheels of the vehicle may be adapted to run on rails.

In a third aspect, the present invention provides a combustion engine operated by means of any compatible fuel and operatively connected to apparatus according to the first aspect of the invention.

The combustion engine may be operated by petrol or diesel. The combustion engine may be a two-stroke engine.

The present invention will be illustrated, merely by way of example, in the following description and with reference to the accompanying drawings in which: Figure 1 is an isometric view of apparatus according to one embodiment of the present invention; and Figure 1 is an isometric view of apparatus according to one embodiment of the present invention; and Figure 2 is a side view of apparatus shown in Figure 1.

The apparatus shown in Figure 1 includes two elongate members 1,2 pivotally attached to a support frame 3. The elongate members 1, 2 can pivot on pivot means which are in the form of a split-shaft comprising shaft members 4,5.

The support frame 3 consists essentially of a rectangular box frame having two opposed sides 6,7 and two opposed ends 8,9. Internal supports 10,11 extend along the length of the frame from one end 8 to the other end 9.

Each of the sides 6,7 and the supports 10,11 are provided with cut-outs which define two transversely-extending bores 12,13 whose longitudinal axes are offset relative to each other. One member 4,5 rotates in each bore 12,13 respectively.

The members 4,5 lie adjacent each other for the part of their length defined between the supports 10 and 11. Shaft member 4 has a toothed cog 14 mounted on the part between the supports 10,11, and shaft member 5 has a toothed cog 15 mounted thereon in the same way. The cogs 14,15 have teeth which intermesh as shown in Figure 1. Pivoting of elongate member 1 on the shaft piece 4 causes the shaft member 4 to rotate in its bore 12, thereby causing shaft member 5 to rotate in its bore 13.

At the upper end of each elongate member 1, 2 an input connection part 16,17 respectively operatively connects each elongate member 1,2 to a piston assembly 18,19 respectively. The pistons 18a and 18b move within bores (not shown) in a reciprocative manner whereby elongate member 1 is pivoted on the shaft member 4. In turn, the shaft member 4 will rotate within the bore 12. Similarly, pistons 19a and 19b act to pivot elongate member 2 on shaft member 5 which rotates in its bore 13.

Plates 20,21 extending from the underside of the frame 3, connect rotatable wheels 22,23 to the underside of the frame substantially proximal to frame ends 8 and 9 respectively. The wheels 22,23 are located so that they can be operatively connected to other parts of the apparatus. Each wheel 22,23 rotates about pin 24a, 24b, the rotation being driven by an endless belt 25. The belt engages a grooved portion 26 around the circumference of each wheel. The belt is tensioned to provide adequate engagement between the belt and the wheel.

Referring to Figure 2, the pins 24a, 24b pass through the centre of each wheel 22,23 respectively and engage a lower plate 26. Plate 26 encloses the wheels 22,23 between itself and the base surface of the support frame 3. The belt 25 extends around part of the circumference of each wheel, preferably around that part of the circumference subtended by 180 from the centre of each wheel. The distance between the axial mid-plane of the belt and the underside of the support frame 3 may be varied.

The endless belt 25 is connected to the lower end of each elongate member 1,2 by means of output connection parts 27,28 respectively. The connection is float-adjustable to allow the connection to be maintained and yet slide up the length of the elongate member during use of the apparatus. The belt 25 extends around the circumference of each of the wheels 22,23 to place the belt 25 under tension.

In use, the elongate members 1, 2 are initially (for the purposes of an illustrative example) in the positions relative to the box 3 as shown in the figures. The piston 18a extends from its cylindrical bore (not shown) and piston 18b retracts into its cylindrical bore (not shown) to pivot elongate member 1 on shaft member 4, which in turn rotates within its bore 12.

Similarly, piston 19a extends from its bore whilst piston 19b retracts into its bore to pivot elongate member 2 on shaft member 5, in turn rotating within its bore 13.

The meshing gears formed by cogs 14,15 ensure that the pivoting of each elongate member 1,2 is simultaneous and synchronised, the spacing of the teeth on each cog 14,15 being suitable for this purpose.

The elongate member 1 pivots to an angular position relative to the support frame 3 which the elongate member 2 originally occupied, and the elongate member 2 pivots to an angular position relative to the support frame 3 originally occupied by elongate member 1. The length of belt 25 shown in Figure 2 moves in the direction of the arrow A being driven by the pivoting movement of the elongate member 1. The wheels 22,23 rotate in one direction as the elongate members 1,2 swing on their pivots. The first half-cycle is complete when each elongate member 1,2 has moved to the position relative to the support frame 3 which the other elongate member previously occupied at the initial position.

At the completion of the first half-cycle, the pistons of the piston assemblies 18,19 move in opposite directions to those of the first half cycle to return simultaneously each elongate member 1,2 back to its original angular position relative to the support frame 3 as shown in Figures 1 and 2. During the return half-cycle, the length of belt shown in Figure 2 moves in the opposite direction to that indicated by the arrow A, and the wheels 22,23 rotate in the opposite direction to the direction of the rotation during the first half-cycle.

The full cycle is complete when the elongate members have returned to their original positions. A ratchet means (not shown) is operatively connected to each wheel 22,23 to convert the rotations in opposite directions of each wheel into a single continuous rotation suitable for driving a flywheel.

The bores 12,13 defined by the support frame 3 may be eccentric relative to the circumference of the split shaft members 4,5 in order to allow a degree of vertical movement of each elongate member 1,2 relative to the support frame 3. In this way, the pistons 18a, 18b, 19a, 19b, whose plane of operation would otherwise change in height relative to the support frame 3 during pivoting of the elongate members 1,2, can be fixed to the support frame 3, the eccentric or elongate bores compensate, avoiding the need for vertical displacement. In the same way, the float adjustment on each elongate member 1,2 at the output connection parts 27,28 allows the connection to slide along the length of the elongate member 1,2.

Depending on the intended field of use of the apparatus, the spacing of the belt 25 beneath the support frame 3 can be varied so that the output connection parts 27,28 can be located further towards the lower extremity of each elongate member 1,2 respectively.

As an alternative to the output connection parts 27,28 shown in the drawings, each elongate member may include a substantially semicircular, toothed portion which is adapted to engage complementary recesses in the belt 25.

Claims

CLAIMS 1. Apparatus adapted in use to connect operatively a source of motive power to a vehicle drive means, in which the apparatus comprises at least two elongate members each having input and output connection parts, each elongate member being pivotally attached to a support frame at a point along the length of each elongate member between said input and output connection parts, the pivoting of each elongate member being driven in consecutive drive cycles by output from the source of motive power wherein one half of each drive cycle consists of the first elongate member being pivoted from a first angular position relative to the support frame to a second angular position relative to the support frame while the second elongate member is pivoted from said second angular position to said first angular position relative to the support frame, the second elongate member being pivoted in a plane substantially parallel to the first elongate member and spaced therefrom, and the other half of each drive cycle consists of the elongate members being returned simultaneously to each of their respective previous angular positions, and output means operatively connected to the output connection part of each elongate member, the output means being adapted to convert the consecutive half cycles into a continuous rotary movement suitable for driving a clutch flywheel.
2. Apparatus according to claim 1 in which the output of the source of motive power comprises at least one piston moveable in a bore, said at least one piston being operatively connected to the input connection part of each elongate member to pivot or swing the elongate member about pivot means provided on the support frame.
3. Apparatus according to claim 2 in which two pistons power the pivoting of each elongate member, one piston extending from the bore during one half cycle, then retracting into the bore during the subsequent half cycle, the other piston, disposed opposite to the first piston, extending and retracting in its bore in the opposite sense to the first piston, so that the pistons work co-operatively to swing the elongate member between the two angular positions.
4. Apparatus according to any one of claims 1 to 3 in which the pivot means comprises a split-shaft having two parallel, axially-offset members and extending transversely across the support frame.
5. Apparatus according to claim 4 in which each shaft member rotates axially in its bore during the pivoting of its associated elongate member.
6 Apparatus according to claim 4 or 5 in which the split-shaft has an integrated gear mechanism which allows synchronisation of the movement of the elongate members during each half cycle.
7. Apparatus according to claim 4,5 or 6 in which the lengths of the two shaft members are such that a part of one shaft member lies adjacent a part of the other shaft member when the split-shaft is attached across the support frame.
8. Apparatus according to claim 7 in which a toothed cog is fitted to that part of each shaft member which lies adjacent the other shaft member, so that the teeth of one cog engage the teeth of the other cog.
9. Apparatus according to any preceding claim in which the pivot means is located and rotates in an eccentric or elongate bore provided in each elongate member in order to allow vertical displacement of each elongate member relative to the support frame.
10. Apparatus according to any preceding claim in which the output means comprises a flexible member which attaches to the output connection part of each elongate member, and which includes a loop portion extending between the elongate members.
11. Apparatus according to claim 10 in which the loop portion, under tension, engages and rotates at least one wheel or other rotatable member.
12. Apparatus according to claim 10 or 11 in which the flexible member is endless.
13. Apparatus according to claim 12 in which the flexible member is a belt.
14. Apparatus according to claim 12 in which the flexible member is a chain.
15. Apparatus according to claim 12,13 or 14 in which the endless flexible member rotates two wheels or rotatable members.
16. Apparatus according to any one of claims 11 to 15 in which ratchet means are provided to convert alternate rotations of said at least one rotatable member into a continuous rotation in a single direction.
17. Apparatus according to any one of claims 10 to 16 in which the flexible member is attached to the output connection part of each elongate member by means of a float adjustment.
18. Apparatus according to claim 17 in which the float adjustment comprises a slide attached to and moveable relative to the length of the elongate member.
19. Apparatus according to any one of claims 10 to 16 in which each elongate member includes a substantially semi-circular, toothed portion proximal to the output connection part, the toothed portion being adapted to engage complementary recesses on the flexible member to drive the flexible member when it is under tension during each half-cycle.
20. A transport vehicle comprising a vehicle body and a plurality of wheels, and including apparatus in accordance with any one of claims 1 to 19 wherein the flywheel is adapted to drive at least one of the wheels.
21. A transport vehicle according to claim 20 in which the vehicle is a tram, bus or passenger car.
22. A transport vehicle according to claim 20 in which the wheels of the vehicle are adapted to run on rails.
23. A combustion engine operated by means of any compatible fuel and operatively connected to apparatus in accordance with any one of claims 1 to 19.
24. A combustion engine according to claim 23 in which the combustion engine is operated by petrol or diesel.
25. A combustion engine according to claim 23 in which the combustion engine is a two-stroke engine.
26. Apparatus for transmitting power to vehicle drive means substantially as described herein with reference to and as shown in the accompanying drawings.