Technical Field

The present invention relates to a hand powered gearbox that takes a push-pull or alternating essentially linear motion and converts it to a rotational motion. The invention can be used to drive pumps, generators, land, air and water vehicles or anything else that can be rotationally driven.

Background Art

There are many devices that use a rotational motion to drive a further device that requires a rotational input. There are also devices that take a rotational motion and convert it to a linear or back and forth motion. Many of the devices used for this purpose use electricity or burn fuel which can limit their use.

There are devices that take rotational input from a user and use this to power various means of transport, such as bicycles. Some of these devices power such things as pumps and generators, many are driven by a users legs. There are users that are unable or prefer not to use their legs to drive such devices, they tend to use their arms. To rotationally drive a device with the arms involves good co-ordination, which some users do not have, this can make these devices difficult to use.

Any discussion of the prior art throughout the specification is not an admission that such prior art is widely known or forms part of the common general knowledge in the field.

It is therefore an object of this invention to provide a means of creating a rotational output that does not require a rotational input and/or provide a consumer with a useful choice.

Disclosure of Invention

The present invention provides a drive unit including a drive rack and a drive module.

Preferably where: - the drive rack is a bar that includes rack teeth on two opposite sides, said opposite sides being a first side and a second side;

the drive module includes

• a first rack gear;

· a second rack gear;

• at least one primary drive gear;

• at least one secondary drive gear;

• at least one tertiary drive gear;

• a primary shaft, a secondary shaft and at least one tertiary shaft;

wherein the or each primary drive gear and the first rack gear are mounted on the primary shaft, the or each secondary drive gear and the second rack gear are mounted on the secondary shaft and the or each tertiary drive gear is mounted on an associated tertiary shaft, such that the, or a first, primary drive gear and the, or a first, secondary gear are meshed with the, or a first, tertiary gear but not each other; the first rack gear is dimensioned and configured to mesh with the rack teeth on the first side of the drive rack and the second rack gear is dimensioned and configured to mesh with the rack teeth on the second side of the drive rack, each said primary drive gear and secondary drive gear includes, or is attached to the associated shaft by, a freewheel device configured to allow that drive gear, when in use, to be driven by the associated shaft in only one direction, and freewheel in the other.

Preferably the drive unit includes the drive unit includes at least one drive arm which, when in use, is configured to allow a user to move the drive rack through the drive unit rotating the rack gears.

Preferably at least one drive arm includes or is a handle;

Preferably the or each drive arm is directly or indirectly connected to the drive rack. In a highly preferred form there are second drive gears in addition to the first drive gears, the first tertiary drive gear being attached to the first tertiary shaft and the second tertiary drive gear being attached to a second tertiary shaft. Preferably the first drive gears are located on one side of the drive module and the second drive gears are located on a second side of the drive module. Preferably the at least one drive arm includes the handle, and a linking arm, said linking arm includes a first pivot point and a second pivot point, where the handle is located at a first end of the linking arm and the second pivot point is located at, or close to, a second end of the linking arm such that the second pivot point provides a pivotable connection to a primary end of the drive rack. Preferably, in use, the drive arm pivots about the first pivot point.

Preferably the drive unit is incorporated into one of the following, a land vehicle, a water vehicle, an aircraft, a pump, a generator, a compressor, a refrigeration plant or similar.

Preferably the drive module includes two module plates, the module plates separate the rack gears from the drive gears and locate the shafts. Preferably the drive unit includes at least one drive connection means. Preferably each drive connection means includes a first sprocket or pulley attached to the or each tertiary shaft and a second sprocket or pulley attached to an axle, said axle being part of the device to be driven by the drive unit. Brief Description of Drawings

By way of example only, a preferred embodiment of the present invention is described in detail below with reference to the accompanying drawings, in which:

Figure 1 is a side view of the hand powered drive unit;

Figure 2 is a front view of the hand powered drive unit;

Figure 3 is a front view of the drive module, with two output means, engaged with the drive rack;

Figure 4 is a side view of the drive module; Figure 5 is a cross sectional view of the drive module engaged with the drive rack along the line A-A in the direction of the arrows;

Figure 6 is a diagrammatic view of the hand powered drive unit, viewed in the direction of Arrow B, in use with the drive handle moving away from the drive module;

Figure 7 is a diagrammatic view of the hand powered drive unit, viewed in the direction of Arrow B, in use with the drive handle moving towards the drive module;;

Figure 8 is a side view of the drive unit attached by a drive connection means to an axle; Figure 9 is a side view of a hand powered land vehicle incorporating the drive unit with the drive connection means;

Best Mode for Carrying Out the Invention

Referring to figures 1 and 2 a drive unit (1 ) including a drive arm (2), drive module (3) and drive rack (4) is shown.

The drive arm (2) includes a handle (6) and a linking rod (7), with the handle (6) being attached to a first end (8) of the linking rod (7). The handle (6) shown is similar to the handle bars on a bicycle, but could be any suitable form that is easy for a user to grasp with one or both hands. In general the plane that the handle (6) lies in will be perpendicular to the plane that the linking rod (7) lies in. The linking rod (7) is a bar or tube (not necessarily round in cross section) of a suitably rigid material, metal, wood, plastic, reinforced plastic or similar, which may be straight or bent. The linking rod (7) includes a first pivot point (10) and a second pivot point (1 1 ). The first pivot point (10) is located some distance from the first end (8) of the linking rod (7) and the second pivot point (1 1 ) is located at the opposite end of the linking rod (7) to the handle (6) i.e. the second end (12) of the linking rod (7).

In use the first pivot point (10) acts as a centre of rotation for the drive arm (2). This is most likely to be accomplished by mounting the first pivot point (10) onto a shaft attached to a framework (not shown), with a bearing, bush or similar allowing the free rotation of the first pivot point (10) on the shaft.

The second end (12) of the linking rod (7) is pivotally connected to a primary end (15) of the drive rack (4) by the second pivot point (1 1 ). The drive rack (4) is a rack, toothed bar (not necessarily round, rectangular or square in cross section), which includes rack teeth (20) on two opposite sides, a first side (21 ) and a second side (22). The rack teeth (20) running along at least part of the length of the drive rack (4).

Referring to figures 3 to 5 the drive module (3) is shown, in figure 5 a side view of the drive module is shown in cross section engaged with the drive rack (4). The drive module includes the following: two rack gears (25, 26), a first rack gear (25) and a second rack gear (26);

two primary drive gears (27,28), a first primary drive gear (27) and a second primary drive gear (28);

two secondary drive gears (29,30), a first secondary drive gear (29) and a second secondary drive gear (30);

two tertiary gears (31 ,32), a first tertiary drive gear (31 ) and a second tertiary drive gear (32);

two module plates (33,34), a first module plate (33) and a second module plate (34);

a primary shaft (36),

a secondary shaft (37), and

two tertiary shafts (39,40), a first tertiary shaft (39) and a second tertiary shaft (40).

Each gear (25,26,27,28,29,30,31 ,32) is a toothed gear of known type and each module plate (33,34) is a flat plate of a rigid or essentially rigid material such as metal, wood, a reinforced or non reinforced polymer or plastic material or similar. The centreline of each gear (25,26,27,28,29,30,31 ,32) is essentially parallel to the centrelines of the shafts (36,37,39,40) and essentially perpendicular to the planes that each of the module plates (33,34) lie on. Each module plate (33,34) lies on a separate but essentially parallel plane. The centrelines of each of the shafts (25,26,27,28,29,30,31 ,32) are essentially parallel..

The two primary gears (27,28) are separated by the module plates (33,34) and the first rack gear (25), with the first rack gear (25) located between the two module plates (33,34). The two primary gears (27,28) and the first rack gear (25) are mounted on the primary shaft (36).

The two secondary gears (29,30) are separated by the module plates (33,34) and the second rack gear (26), with the second rack gear (26) located between the two module plates (33,34). The two secondary gears (29,30) and the second rack gear (26) are mounted on the secondary shaft (37). The module plates (33,34) locate the drive gears (27,28,29,30,33,31 ,32) such that the first primary drive gear (27) and first secondary drive gear (29) are meshed with the first tertiary drive gear (31 ) but not each other; and the second primary drive gear (28) and second secondary drive gear (30) are meshed with the second tertiary drive gear (32) but not each other.

The first tertiary drive gear (31 ) is connected (keyed, welded etc) to the first tertiary shaft (39) and rotatively mounted in the first module plate (33) by known means (bushes or bearings for example). Similarly the second tertiary drive gear (32) is rigidly connected to the second tertiary shaft (40) which is rotatively mounted in the second module plate (34) by known means.

Each of the primary and secondary drive gears (27,28,29,30) incorporates, or is attached to the associated shaft (36,37) by, a freewheel clutch (or other freewheel device) of known design, for example a sprag clutch. In use the freewheel clutch/device allows that primary or secondary gear (27,28,29,30) to be driven by the shaft (36,37) to which it is attached in one direction only, and freewheel in the other. In the freewheeling state the peripheral edge of the primary or secondary gear (27,28,29,30) concerned is driven by the tertiary gear (31 ,32) with which it is meshed whereas the centre is driven by the primary or secondary shaft (36,37) on which it is mounted.

Looking specifically at figure 5 the drive module (3) is shown in cross section. The first rack gear (25) is dimensioned and configured to mesh with the rack teeth (20) on the first side (21 ) of the drive rack (4), and the second rack gear (26) is dimensioned and configured to mesh with the rack teeth (20) on the second side (22) of the drive rack (4). When engaged with the drive module (3) the centreline of the drive rack (4) extends through the drive module (3) essentially perpendicular to the centrelines of the shafts (36,37,39,40).

Referring to figures 6 and 7 a preferred mode of operation of the drive unit (1 ), viewed in the direction of arrow B, is shown.

In figure 6 as the handle (6) is moved in the direction of arrow I, which is away from the drive module (3), it causes the drive arm (2) to pivot about the first pivot point (10) which pushes the drive rack (4) through the drive module (3) in the direction of Arrow V.

As the drive rack (4) is pushed through the drive module (3) in the direction of Arrow V it drives the first rack gear (25) (not visible in figure 6) clockwise and the second rack gear (26) (not visible in figure 6) anti-clockwise which in turn drives the primary shaft (36) in a clockwise direction and the secondary shaft (37) in an anticlockwise direction.

The secondary shaft (37) drives the secondary drive gears (29,30) in the direction of Arrow Z (anticlockwise), which in turn drives the associated tertiary drive gear (31 ,32) in the direction of Arrow Y (clockwise). Each tertiary drive gear (31 ,32) drives the associated tertiary shaft (38,39) in the direction of Arrow Y (clockwise). The primary drive gears (27,28) freewheel in the direction of Arrow X (anticlockwise) allowing the primary shaft (36) to turn clockwise.

In figure 7 as the handle (6) is moved in the direction of Arrow 1 1, which is towards the drive module (3), it causes the drive arm (2) to pivot about the first pivot point (10) which pulls the drive rack (4) through the drive module (3) in the direction of Arrow VI. As the drive rack (4) is pulled through the drive module (3) in the direction of Arrow VI it drives the first rack gear (25) (not visible in figure 7) anticlockwise, and the second rack gear (26) (not visible in figure 7) clockwise, which in turn drives the primary shaft (36) in an anticlockwise direction, and the secondary shaft (37) in a clockwise direction.

The primary shaft (37) drives the primary drive gears (27,28) in the direction of Arrow X (anticlockwise), which in turn drives the associated tertiary drive gear (31 ,32) in the direction of Arrow Y (clockwise). Each tertiary drive gear (31 ,32) drives the associated tertiary shaft (38,39) in the direction of Arrow Y (clockwise). The secondary drive gears (29,30) freewheel in the direction of Arrow Z (anticlockwise) allowing the secondary shaft (36) to turn clockwise.

In other words, depending on the direction the drive rack (4) is moving, in this preferred mode of operation, either the primary drive gears (27,28) or the secondary drive gears (29,30) are driving the tertiary gears (31 ,32). This translates the essentially push-pull motion of the drive arm (2) into a clockwise motion of the tertiary drive shafts (38,39). If the primary and secondary drive gears (27,28,29,30) were solid (that is not of a freewheel design), or not mounted on a free wheel device, then no rotation of the tertiary gears (38,39) would be possible. In use, in the just described preferred mode of operation, both of the tertiary shafts (38,39) are driven in the same direction and they can be used to drive a variety of devices.

Referring to figure 8 the drive unit (1 ) is shown connected to an axle (40) by a drive connection means (41 ) which includes a first sprocket (42), a second sprocket (43) and a chain (45). The chain (45) is dimensioned and configured to transmit the drive from the first sprocket (42) to the second sprocket (43). The first sprocket (42) is attached to the first tertiary drive shaft (39) and the second sprocket (43) is connected to the axle (40). In some embodiments the drive connection means (41 ) includes a Derailleur gear system of known type, or a known alternative means that allows variable gearing. In some embodiments the sprockets (42,43) may be pulleys or similar.

Figure 9 shows a hand powered land vehicle (44) including the drive unit (1 ), wheels (46), a structural framework (47) and a seat (48). At least one of the wheels (46) is attached to and configured to be driven by the axle (40). The drive unit (1 ) is connected to the axle (40) by the drive connection means (41 ) described above. The structural framework (47) provides the skeleton for the land vehicle (45) and supports the seat (48). There are four wheels (46), one located close to each corner of the land vehicle (45), certain configurations may vary this number.

In an alternative embodiment of the drive module (3) could have only the first primary, secondary and tertiary drive gears (27,29,31 ) present. In this embodiment there is only a single tertiary shaft (39) present.

A further alternative embodiment, when the drive unit (1 ) is in use, one primary drive gear (27,28) and one secondary drive gear (29,30) is driven the remaining primary and secondary gear (27,28,29,30) freewheel. In this configuration each of the two tertiary shafts (38,39) is driven in a single, but opposite, direction to the other. In further embodiments (not shown) the drive unit (1 ) is incorporated into a pump, a generator, a water craft, an aircraft or any other application which can use a rotational input to operate. In a further embodiment (not shown) the drive arm (2) consists only of the handle (6) which is directly connected to the drive rack (4) such that in use the user alternately, directly, pushes and pulls the drive rack (4) through the drive module (3). This removes the mechanical advantage afforded by the pivoted linking rod (7) but in some applications a simpler and possibly smaller, mechanical device may be desirable.

In some embodiments the sprocket (42,43) includes an over-run clutch so that when the drive unit (1 ) is in use the momentary pause that may occur at each end of the push or pull does not translate into a sudden deceleration of the tertiary shaft (s) (31 ,32). Alternatively some other overrun clutch or similar device is present further through the drive chain.

In a further embodiment (not shown) the axle (40) is in fact two stub axles connected to a differential of known type. In further embodiments (not shown) there is a drive arm (2) and/or handle (6) located at or close to each terminal end of the drive rack (4). In this configuration more than one user can push/pull the drive rack (4) through the drive module (3), alternatively the device to which the drive module (3) is attached can be used in different orientations. For example one user could be at each end of the drive rack (4), these users acting co-operatively push/pull the drive rack (4) through the drive module (3).

It should be noted that it is possible to attach more than one handle (6) or drive arm (2) close to, or at, the or each end of the drive rack (4), for example to allow more than one user to push/pull the drive rack through the drive module (3).

Key

Drive unit

2 Drive arm

3 Drive module

4 Drive rack 5

6 handle

7 linking rod

8 first end (of the linking rod)

9

10 first pivot point

1 1 second pivot point

12 second end (of the linking rod)

13

14

15 Primary end (of the drive rack)

16

17

18

19

20 Rack teeth

21 First side (of the drive rack)

22 Second side (of the drive rack)

23

24

25 First rack gear

26 Second rack gear

27 First primary drive gear

28 Second primary drive gear

29 First secondary drive gear

30 Second secondary drive gear

31 First tertiary drive gear

32 Second tertiary drive gear

33 First module plate

34 Second module plate

35

36 Primary shaft

37 Secondary shaft

38 First tertiary shaft

39 Second tertiary shaft

40 axle drive connection means

First Sprocket/pulley

Second sprocket/pulley

Hand powered land vehicle chain/belt

Wheels

Structural framework

Seat