FIELD OF INVENTION

The present invention relates to a gearbox. The present invention has particular but not exclusive application for use with electric motors. The patent specification describes this use but it is by way of example only and the invention is not limited to this use.

BACKGROUND OF THE INVENTION

Gearboxes have been extensively used to change an output rotational speed relative to an input rotational speed. Gearboxes can be simple gearboxes where the gear ratio cannot be changed, and can be used to convert a higher input speed to a lower output speed (a reduction), or to convert a lower input speed to a higher output speed (an increase).

A problem with most gearboxes is that the efficiency decreases with larger differences in input torque and output torque.

OBJECT OF THE INVENTION

It is an object of the present invention to overcome or at least alleviate one or more of the above mentioned problems with gearboxes and/or provide the consumer with a useful or commercial choice.

SUMMARY OF THE INVENTION

In one aspect, the present invention broadly resides in a gearbox having a first drive member movable in a linear direction; a second drive member movable in a linear direction; a third drive member operatively associated with the first drive member, wherein movement of the first drive member in a linear direction causes rotation of the third drive member; a fourth drive member operatively associated with the second drive member, wherein movement of the second drive member in a linear direction causes rotation of the fourth drive member; a seventh drive member operatively associated with the third drive member such that rotation of the third drive member in a first direction causes rotation of the seventh drive member in a first direction; an eighth drive member operatively associated with the fourth drive member such that rotation of the fourth drive member in a first direction causes rotation of the eighth drive member in a first direction; a first drive shaft operatively associated with the seventh drive member and the eighth drive member, such that movement of the seventh drive member in the first direction causes movement of the first drive shaft in a first direction and such that movement of the eighth drive member in the first direction causes movement of the first drive shaft in the first direction; a first one way clutch located between the third drive member and the first drive shaft to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction; and a second one way clutch located between the fourth drive member and the first drive shaft to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction.

Preferably the gearbox further includes a first input member operatively associated with the first drive member such that rotation of the first input member in a first direction causes linear movement of the first drive member in a first direction. Preferably the first input member is a ball screw. Preferably, rotation of the first input member in a second direction causes linear movement of the first drive member in a second direction.

Preferably the gearbox further includes a second input member operatively associated with the second drive member such that rotation of the second input member in a first direction causes linear movement of the second drive member in a first direction. Preferably the second input member is a ball screw. Preferably, rotation of the second input member in a second direction causes linear movement of the second drive member in a second direction.

Preferably when the first input member rotates in the first direction, the second input member rotates in a second direction. Preferably when the second input member rotates in the first direction, the first input member rotates in a second direction.

Preferably the gearbox includes a first motor to drive the first input member. Preferably the first motor is an electric motor. Preferably rotation of the first motor in a first direction causes movement of the first input member in the first direction. Preferably rotation of the first motor in a second direction causes movement of the first input member in the second direction.

Preferably the gearbox includes a second motor to drive the second input member. Preferably the second motor is an electric motor. Preferably rotation of the second motor in a first direction causes movement of the second input member in the first direction. Preferably rotation of the second motor in a second direction causes movement of the second input member in the second direction.

Preferably the first motor and the second motor rotate at substantially the same speed.

Preferably the gearbox includes a first sensor to detect when the first drive member has reached a predetermined position in the first direction. Preferably when the first sensor detects that the first drive member has reached a predetermined position in the first direction, the first motor is caused to change from rotating in the first direction to rotating in the second direction. Preferably the gearbox includes a second sensor to detect when the first drive member has reached a predetermined position in the second direction. Preferably when the second sensor detects that the first drive member has reached a predetermined position in the second direction, the first motor is caused to change from rotating in the second direction to rotating in the first direction.

Preferably the gearbox includes a third sensor to detect when the second drive member has reached a predetermined position in the first direction. Preferably when the third sensor detects that the second drive member has reached a predetermined position in the first direction, the second motor is caused to change from rotating in the first direction to rotating in the second direction. Preferably the gearbox includes a fourth sensor to detect when the second drive member has reached a predetermined position in the second direction. Preferably when the fourth sensor detects that the second drive member has reached a predetermined position in the second direction, the second motor is caused to change from rotating in the second direction to rotating in the first direction. Preferably the gearbox includes a fifth drive member associated with the third drive member. Preferably the fifth drive member rotates with the third drive member in at least the first direction. Preferably the fifth drive member is operatively associated with the seventh drive member such that rotation of the fifth drive member in the first direction causes rotation of the seventh drive member in the first direction. Preferably the fifth drive member engages with the seventh drive member. Preferably the fifth drive member is operatively connected to the third drive member by a first connecting shaft.

Preferably the gearbox includes a sixth drive member associated with the fourth drive member. Preferably the sixth drive member rotates with the fourth drive member in at least the first direction. Preferably the sixth drive member is operatively associated with the eighth drive member such that rotation of the sixth drive member in the first direction causes rotation of the eighth drive member in the first direction. Preferably the sixth drive member engages with the eighth drive member.

Preferably the sixth drive member is operatively connected to the fourth drive member by a second connecting shaft.

Preferably the first one way clutch is located between the seventh drive member and the first drive shaft. In another embodiment, the first one way clutch is located between the fifth drive member and the first connecting shaft. In a further embodiment, the first one way clutch is located between the third drive member and the first connecting shaft.

Preferably the second one way clutch is located between the eighth drive member and the first drive shaft. In another embodiment, the first one way clutch is located between the sixth drive member and the second connecting shaft. In a further embodiment, the first one way clutch is located between the fourth drive member and the second connecting shaft.

Preferably the gearbox includes a first output member operatively associated with the first drive shaft. Preferably the first output member is attached to the first drive shaft. Preferably rotation of the first drive shaft in the first direction causes rotation of the first output member in a first direction.

Preferably the gearbox further includes a second output member operatively associated with the first output member, such that rotation of the first output member in a first direction causes rotation of the second output member in a first direction. Preferably the gearbox further includes a third output member operatively associated with the second output member. Preferably the third output member rotates with the second output member in at least the first direction. Preferably the third output member is fixedly attached relative to the second output member. Preferably the second output member is attached to a first output shaft. Preferably the third output member is attached to the first output shaft.

Preferably the gearbox further includes a fourth output member operatively associated with the third output member, such that rotation of the third output member in a first direction causes rotation of the fourth output member in a first direction.

Preferably the gearbox further includes a fifth output member operatively associated with the fourth output member. Preferably the fifth output member rotates with the fourth output member in at least the first direction. Preferably the fifth output member is fixedly attached relative to the fourth output member. Preferably the fourth output member is attached to a second output shaft. Preferably the fifth output member is attached to the second output shaft.

Preferably the first drive member is a rack. Preferably the first drive member includes a portion that engages with the first input member. Preferably the portion includes a ball assembly which engages with the ball screw.

Preferably the second drive member is a rack. Preferably the second drive member includes a portion that engages with the second input member. Preferably the portion includes a ball assembly which engages with the ball screw.

Preferably the second drive member is substantially the same size as the first drive member. Preferably when the first drive member is moving in the first direction, the second drive member moves in a second direction. Preferably when the second drive member moves in the first direction, the first drive member moves in a second direction.

Preferably the third drive member is a pinion gear. Preferably the third drive member engages with the first drive member.

Preferably the fourth drive member is a pinion gear. Preferably the fourth drive member engages with the second drive member. Preferably the fourth drive member is substantially the same size as the third drive member. Preferably the fifth drive member is a gear. Preferably the sixth drive member is a gear. Preferably the fifth drive member is substantially the same size as the sixth drive member.

Preferably the seventh drive member is a gear. Preferably the seventh drive member engages with the fifth drive member. In one embodiment, the seventh drive member engages with the third drive member. Preferably the seventh drive member is larger than the fifth drive member. Preferably the seventh drive member is larger than the third drive member.

Preferably the eighth drive member is a gear. Preferably the eighth drive member engages with the sixth drive member. In one embodiment, the eighth drive member engages with the fourth drive member. Preferably the eighth drive member is larger than the sixth drive member. Preferably the eighth drive member is larger than the fourth drive member. Preferably the eighth drive member is substantially the same size as the seventh drive member.

Preferably the first output member is a gear. Preferably the first output member is smaller than the seventh drive member. Preferably the first output member is smaller than the eighth drive member

Preferably the second output member is a gear. Preferably the second output member engages with the first output member. Preferably the second output member is larger than the first output member.

Preferably the third output member is a gear. Preferably the third output member is smaller than the second output member.

Preferably the fourth output member is a gear. Preferably the fourth output member engages with the third output member. Preferably the fourth output member is larger than the third output member.

Preferably the fifth output member is a gear. Preferably the fifth output member is smaller than the fourth output member.

Preferably the gearbox includes a cover. Preferably the fifth output member is located outside of the cover. In one embodiment, the first motor and the second motor are located outside the cover.

In another embodiment, some of the drive members and/or output members may be sprockets. Preferably the sprockets engage with corresponding sprockets via one or more chains. Preferably the fifth output member rotates at a slower speed than the first or second motor.

In another aspect, the present invention broadly resides in a gearbox having a first drive member movable in a linear direction; a second drive member movable in a linear direction; a seventh drive member operatively associated with the first drive member, wherein movement of the first drive member in a first direction causes rotation of the seventh drive member in a first direction; an eighth drive member operatively associated with the second drive member, wherein movement of the second drive member in a first direction causes rotation of the eighth drive member in a first direction; a first drive shaft operatively associated with the seventh drive member and the eighth drive member, such that movement of the seventh drive member in the first direction causes movement of the first drive shaft in a first direction and such that movement of the eighth drive member in the first direction causes movement of the first drive shaft in the first direction; a first one way clutch located between the seventh drive member and the first drive shaft to inhibit movement of the first drive shaft in a second direction when the first drive member moves in a second direction; and a second one way clutch located between the eighth drive member and the first drive shaft to inhibit movement of the first drive shaft in a second direction when the eighth drive member moves in a second direction.

Preferably the gearbox includes a third drive member operatively associated with the first drive member, wherein movement of the first drive member in a linear direction causes rotation of the third drive member; and a fourth drive member operatively associated with the second drive member, wherein movement of the second drive member in a linear direction causes rotation of the fourth drive member, wherein the seventh drive member is operatively associated with the third drive member such that rotation of the third drive member in a first direction causes rotation of the seventh drive member in a first direction, and wherein the eighth drive member is operatively associated with the fourth drive member such that rotation of the fourth drive member in a first direction causes rotation of the eighth drive member in a first direction. It will be appreciated that the gearbox may also be referred to as a transmission system.

It will be appreciated that rotation of one member in a first direction may be different to rotation of another member in a first direction, for example if two gears are meshing, rotation of the first gear in a first direction may be clockwise and rotation of the second gear in a first direction may be anti-clockwise.

It will be appreciated that a reference to a ball screw may be a reference to a threaded shaft of a ball screw assembly.

It will be appreciated that a reference to a ball assembly may be a reference to a ball assembly of a ball screw assembly.

In a further aspect, the present invention broadly resides in a gearbox having a first drive member movable in a linear direction; a second drive member movable in a linear direction; a third drive member operatively associated with the first drive member, wherein movement of the first drive member in a linear direction causes rotation of the third drive member; a fourth drive member operatively associated with the second drive member, wherein movement of the second drive member in a linear direction causes rotation of the fourth drive member; a seventh drive member operatively associated with the third drive member such that rotation of the third drive member in a first direction causes rotation of the seventh drive member in a first direction, and operatively associated with the fourth drive member such that rotation of the fourth drive member in a first direction causes rotation of the seventh drive member in a first direction; a first drive shaft operatively associated with the seventh drive member such that movement of the seventh drive member in the first direction causes movement of the first drive shaft in a first direction; a first one way clutch located between the third drive member and the seventh drive member to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction; and a second one way clutch located between the fourth drive member and the seventh drive member to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction.

In another aspect, the present invention broadly resides in a gearbox having a first drive member; a second drive member; a third drive member operatively associated with the first drive member, wherein movement of the first drive member causes rotation of the third drive member; a fourth drive member operatively associated with the second drive member, wherein movement of the second drive member causes rotation of the fourth drive member; a seventh drive member operatively associated with the third drive member such that rotation of the third drive member in a first direction causes rotation of the seventh drive member in a first direction; an eighth drive member operatively associated with the fourth drive member such that rotation of the fourth drive member in a first direction causes rotation of the eighth drive member in a first direction; a first drive shaft operatively associated with the seventh drive member and the eighth drive member, such that movement of the seventh drive member in the first direction causes movement of the first drive shaft in a first direction and such that movement of the eighth drive member in the first direction causes movement of the first drive shaft in the first direction; a first one way clutch located between the third drive member and the first drive shaft to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction; and a second one way clutch located between the fourth drive member and the first drive shaft to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction.

In a further aspect, the present invention broadly resides in a gearbox having a first drive member; a second drive member; a third drive member operatively associated with the first drive member, wherein movement of the first drive member causes rotation of the third drive member; a fourth drive member operatively associated with the second drive member, wherein movement of the second drive member causes rotation of the fourth drive member; - io - a seventh drive member operatively associated with the third drive member such that rotation of the third drive member in a first direction causes rotation of the seventh drive member in a first direction, and operatively associated with the fourth drive member such that rotation of the fourth drive member in a first direction causes rotation of the seventh drive member in a first direction; a first drive shaft operatively associated with the seventh drive member such that movement of the seventh drive member in the first direction causes movement of the first drive shaft in a first direction; a first one way clutch located between the third drive member and the seventh drive member to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction; and a second one way clutch located between the fourth drive member and the seventh drive member to inhibit movement of the first drive shaft in a second direction when the third drive member rotates in a second direction.

The features described with respect to one aspect also apply where applicable to all other aspects of the invention. Furthermore, different combinations of described features are herein described and claimed even when not expressly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention can be more readily understood reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:

Figure 1 is a schematic view of gearbox according to an embodiment of the present invention;

Figure 2 is a lower perspective view of the gearbox of Figure 1 ;

Figure 3 is a top view of the gearbox of Figure 1 ;

Figure 4 is a left side view of the gearbox of Figure 1 ;

Figure 5 is a front view of the gearbox of Figure 1 ;

Figure 6 is a right side view of the gearbox of Figure 1 ;

Figure 7 is a partial exploded view showing more detail of how the seventh and eighth drive member of Figure 1 are attached to the first drive shaft;

Figure 8 is a schematic view of gearbox according to another embodiment of the present invention; - n -

Figure 9 is a lower perspective view of the gearbox of Figure 8;

Figure 10 is a top view of the gearbox of Figure 8;

Figure 11 is a left side view of the gearbox of Figure 8;

Figure 12 is a front view of the gearbox of Figure 8;

Figure 13 is a right side view of the gearbox of Figure 8;

Figure 14 is a partial detailed view showing more detail of how the seventh and eighth drive member of Figure 8 are attached to the first drive shaft; and

Figure 15 is a rear perspective view of the gearbox of Figure 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to Figures 1 to 7, there is shown a gearbox 10. The gearbox has a first motor in the form of electric motor 12, and a second motor in the form of electric motor 14. The electric motor 12 drives a first input member 16. The first input member 16 is a ball screw. The electric motor 14 drives a second input member 18. The second input member 18 is a ball screw.

The first input member 16 moves a first drive member 20 via portions 22,24. Portions 22,24 each include a ball assembly which engage with the first input member 16. The first drive member 20 is a rack. Rotating the first input member 16 in a first direction causes the first drive member 20 to move in a first direction. Rotating the first input member 16 in a second direction causes the first drive member 20 to move in a second direction.

The second input member 18 moves a second drive member 26 via portions 28,30. Portions 28,30 each include a ball assembly which engage with the first input member 18. The second drive member 26 is a rack. Rotating the second input member 18 in a first direction causes the second drive member 26 to move in a first direction. Rotating the second input member 18 in a second direction causes the second drive member 26 to move in a second direction.

The gearbox 10 has a first sensor 32 to determine when the first drive member 20 has reached a predetermined position in the first direction (as shown in Figure 1). When the first sensor 32 detects the first drive member 20, the direction of the first motor 12 is changed to move the first drive member 20 in the second direction. The gearbox 10 has a second sensor 34 to determine when the first drive member 20 has reached a predetermined position in the second direction (not shown). When the second sensor 34 detects the first drive member 20, the direction of the first motor 12 is changed to move the first drive member 20 in the first direction.

The gearbox 10 has a third sensor 36 to determine when the second drive member 22 has reached a predetermined position in the first direction (not shown). When the third sensor 36 detects the second drive member 22, the direction of the second motor 14 is changed to move the second drive member 22 in the second direction. The gearbox 10 has a fourth sensor 38 to determine when the second drive member 22 has reached a predetermined position in the second direction (as seen in Figure 1). When the fourth sensor 38 detects the second drive member 22, the direction of the second motor 14 is changed to move the second drive member 22 in the first direction.

The gearbox 10 has a third drive member 40. The third drive member 40 is a pinion gear which engages with the first drive member 20. Movement of the first drive member 20 in the first direction rotates the third drive member 40 in a first direction. The third drive member 40 is connected to a fifth drive member 42 by a first connecting shaft 44. The fifth drive member 42 is a gear.

The gearbox 10 has a fourth drive member 46. The fourth drive member 46 is a pinion gear which engages with the second drive member 26. Movement of the second drive member 26 in the first direction rotates the fourth drive member 46 in a first direction. The fourth drive member 46 is connected to a sixth drive member 48 by a second connecting shaft 50. The sixth drive member 48 is a gear.

The gearbox 10 includes a seventh drive member 52. The seventh drive member 52 is a gear. The seventh drive member 52 is engaged by the fifth drive member 42. Rotation of the fifth drive member 42 in a first direction causes rotation of the seventh drive member 52 in a first direction. The seventh drive member 52 is mounted to a first drive shaft 54 by a first one way clutch 56 (best seen in Figure 7). The one way clutch 56 inhibits movement of the first drive shaft 54 in a second direction when the seventh drive member 52 rotates in a second direction. The first one way clutch 56 enables movement of the first drive shaft 54 in a first direction when the seventh drive member 52 rotates in the first direction.

The gearbox 10 includes an eighth drive member 58. The eighth drive member 58 is a gear. The eighth drive member 58 is engaged by the sixth drive member 48. Rotation of the sixth drive member 48 in a first direction causes rotation of the eighth drive member 58 in a first direction. The eighth drive member 58 is mounted to a first drive shaft 54 by a second one way clutch 60 (best seen in Figure 7). The one way clutch 60 inhibits movement of the first drive shaft 54 in a second direction when the eighth drive member 58 rotates in a second direction. The second one way clutch 60 enables movement of the first drive shaft 54 in the first direction when the eighth drive member 58 rotates in the first direction.

The gearbox 10 includes a first output member 62. The first output member 62 is a gear. The first output member 62 is attached to the first drive shaft 54. Rotation of the first drive shaft 54 in the first direction rotates the first output member 62 in a first direction.

The gearbox 10 includes a second output member 64. The second output member 64 is a gear. The second output member 64 engages with the first output member 62 such that rotation of the first output member 62 in the first direction causes the second output member 64 to rotate in a first direction. A third output member 66 is attached to the second output member 64 by a first output shaft 68. The third output member 66 is a gear. The third output member 66 rotates in a first direction with the second output member.

The gearbox 10 includes a fourth output member 70. The fourth output member 70 is a gear. The fourth output member 70 engages with the third output member 66 such that rotation of the third output member 66 in the first direction causes the fourth output member 70 to rotate in a first direction. A fifth output member 72 is attached to the fourth output member 70 by a second output shaft 74. The fifth output member 72 is a gear.

With reference to Figures 8 to 15, there is shown a gearbox 110. The gearbox 110 is similar to the gearbox 10 of Figures 1 to 7 except for the relative sizes of the fifth drive member 142, the seventh drive member 152, the sixth drive member 148 and the eighth drive member 158, and the positions of the first one way clutch 156 and the second one way clutch 160, the relative sizes of the first output member 162, the second output member 164, the third output member 166 and the fourth output member 170. The gearbox has a first motor in the form of electric motor 112, and a second motor in the form of electric motor 114. The electric motor 112 drives a first input member 116. The first input member 116 is a ball screw. The electric motor 114 drives a second input member 118. The second input member 118 is a ball screw. The first input member 116 moves a first drive member 120 via portions 122,124. Portions 122,124 each include a ball assembly which engage with the first input member 116. The first drive member 120 is a rack. Rotating the first input member 116 in a first direction causes the first drive member 120 to move in a first direction. Rotating the first input member 116 in a second direction causes the first drive member 120 to move in a second direction.

The second input member 118 moves a second drive member 126 via portions 128,130. Portions 128,130 each include a ball assembly which engage with the first input member 118. The second drive member 126 is a rack. Rotating the second input member 118 in a first direction causes the second drive member 126 to move in a first direction. Rotating the second input member 118 in a second direction causes the second drive member 126 to move in a second direction.

The gearbox 110 has a first sensor 132 to determine when the first drive member 120 has reached a predetermined position in the first direction (as shown in Figure 8). When the first sensor 132 detects the first drive member 120, the direction of the first motor 112 is changed to move the first drive member 120 in the second direction. The gearbox 110 has a second sensor 134 to determine when the first drive member 120 has reached a predetermined position in the second direction (not shown). When the second sensor 134 detects the first drive member 120, the direction of the first motor 112 is changed to move the first drive member 120 in the first direction.

The gearbox 110 has a third sensor 136 to determine when the second drive member 122 has reached a predetermined position in the first direction (not shown). When the third sensor 136 detects the second drive member 122, the direction of the second motor 114 is changed to move the second drive member 122 in the second direction. The gearbox 110 has a fourth sensor 138 to determine when the second drive member 122 has reached a predetermined position in the second direction (as seen in Figure 8). When the fourth sensor 138 detects the second drive member 122, the direction of the second motor 114 is changed to move the second drive member 122 in the first direction.

The gearbox 110 has a third drive member 140. The third drive member 140 is a pinion gear which engages with the first drive member 120. Movement of the first drive member 120 in the first direction rotates the third drive member 140 in a first direction. The third drive member 140 is connected to a fifth drive member 142 by a first connecting shaft 144. The fifth drive member 142 is a gear.

The gearbox 110 has a fourth drive member 146. The fourth drive member 146 is a pinion gear which engages with the second drive member 126. Movement of the second drive member 126 in the first direction rotates the fourth drive member 146 in a first direction. The fourth drive member 146 is connected to a sixth drive member 148 by a second connecting shaft 150. The sixth drive member 148 is a gear.

The gearbox 110 includes a seventh drive member 152. The seventh drive member 152 is a gear. The seventh drive member 152 is engaged by the fifth drive member 142. Rotation of the fifth drive member 142 in a first direction causes rotation of the seventh drive member 152 in a first direction.

The fifth drive member 142 is mounted to the first connecting shaft 144 by a first one way clutch 156 (best seen in Figure 14). The first one way clutch 156 inhibits movement of the fifth drive member 142 in a second direction when the first connecting shaft 144 rotates in a second direction. The first one way clutch 156 enables movement of the fifth drive member 142 in the first direction when the first connecting shaft 144 rotates in the first direction.

The gearbox 110 includes an eighth drive member 158. The eighth drive member 158 is a gear. The eighth drive member 158 is engaged by the sixth drive member 148. Rotation of the sixth drive member 148 in a first direction causes rotation of the eighth drive member 158 in a first direction.

The sixth drive member 148 is mounted to the second connecting shaft 150 by a second one way clutch 160 (best seen in Figure 14). The second one way clutch 160 inhibits movement of the sixth drive member 148 in a second direction when the second connecting shaft 150 rotates in a second direction. The second one way clutch 160 enables movement of the sixth drive member 148 in the first direction when the second connecting shaft 150 rotates in the first direction.

The gearbox 110 includes a first output member 162. The first output member 162 is a gear. The first output member 162 is attached to the first drive shaft 154. Rotation of the first drive shaft 154 in the first direction rotates the first output member 162 in a first direction.

The gearbox 110 includes a second output member 164. The second output member 164 is a gear. The second output member 164 engages with the first output member 162 such that rotation of the first output member 162 in the first direction causes the second output member 164 to rotate in a first direction. A third output member 166 is attached to the second output member 164 by a first output shaft 168. The third output member 166 is a gear. The third output member 166 rotates in a first direction with the second output member.

The gearbox 110 includes a fourth output member 170. The fourth output member 170 is a gear. The fourth output member 170 engages with the third output member 166 such that rotation of the third output member 166 in the first direction causes the fourth output member 170 to rotate in a first direction. A fifth output member 172 is attached to the fourth output member 170 by a second output shaft 174. The fifth output member 172 is a gear.

ADVANTAGES

An advantage of the preferred embodiment of the gearbox includes the ability to convert a high input torque to a high output torque. Another advantage of the preferred embodiment of the gearbox includes the ability to prevent backlash. A further advantage of the preferred embodiment of the gearbox includes the ability to convert low input speeds to a high output speed.

VARIATIONS

While the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

Throughout the description and claims of this specification the word “comprise” and variations of that word such as “comprises" and “comprising”, are not intended to exclude other additives, components, integers or steps.