A steering system includes a steering column for rotation between at least a center position and a range of second positions and defining a central axis. The steering system also includes an actuator assembly in operative communication with the steering column to provide steering assistance, the actuator assembly comprising a pair of plates, each plate including a first helical track and a second helical track. The steering system further includes a spring element arranged with the actuator assembly to bias movement of one of the pair of plates along the central axis to influence the steering column to move to the center position.

A steering system includes a steering column for rotation between at least a center position and a range of second positions and defining a central axis. The steering system also includes an actuator assembly in operative communication with the steering column to provide steering assistance, the actuator assembly comprising a pair of plates, each plate including a first helical track and a second helical track. The steering system further includes a spring element arranged with the actuator assembly to bias movement of one of the pair of plates along the central axis to influence the steering column to move to the center position.

A quick release mechanism for a wheel includes a hub and a clip, which interact with a wheel or roller that may or may not be part of the invention per se. The hub is disposable on a drive shaft such that it will rotate with the drive shaft. An optional hub cap is disposable on the wheel and has an opening that is complimentary to the geometry of the hub to allow engagement thereof such that the hub the hub cap rotate together. The clip is disposable on the hub in a closed or an open position so that the hub cap cannot or can be removed from the hub.

A quick release mechanism for a wheel includes a hub and a clip, which interact with a wheel or roller that may or may not be part of the invention per se. The hub is disposable on a drive shaft such that it will rotate with the drive shaft. An optional hub cap is disposable on the wheel and has an opening that is complimentary to the geometry of the hub to allow engagement thereof such that the hub the hub cap rotate together. The clip is disposable on the hub in a closed or an open position so that the hub cap cannot or can be removed from the hub.

A continuously variable speed transmission and steering differential having a central drive axle, two pairs of sheaves and two shift arms. The drive axel is driven by an external power source. The two pairs of sheaves, left and right, are mounted to the drive axel. Each pair of sheaves includes a fixed drive sheave and a movable drive sheave. Each movable drive sheave is positioned by a shift arm. Shifting the shift arms left or right varies the gear ratio between the left and right pair of sheaves thereby providing steering control. Narrowing the distance between the shaft arms increases the gear ratio and consequently puts the transmission into a higher gear, thereby providing speed control.

A continuously variable speed transmission and steering differential having a central drive axle, two pairs of sheaves and two shift arms. The drive axel is driven by an external power source. The two pairs of sheaves, left and right, are mounted to the drive axel. Each pair of sheaves includes a fixed drive sheave and a movable drive sheave. Each movable drive sheave is positioned by a shift arm. Shifting the shift arms left or right varies the gear ratio between the left and right pair of sheaves thereby providing steering control. Narrowing the distance between the shaft arms increases the gear ratio and consequently puts the transmission into a higher gear, thereby providing speed control.

The present concept is a continuously variable speed transmission and steering differential. It includes a laterally extending central drive axle driven by an external power source, two pairs of drive sheaves mounted to drive axles, and a means for transmitting rotational energy from the drive sheaves to the drive axles. There are two extended shift arms spaced apart for controlling the positioning of movable drive sheaves. Narrowing or increasing the gap between shift arms, does the same for the gap between the drive sheaves, increasing or decreasing the gear ration respectively which provides speed control. Shifting the shift arms left or right varies the gear ratio between the left and right pair of sheaves, providing differential speed between the left and right driven axles, which provides steering control.

The present concept is a continuously variable speed transmission and steering differential. It includes a laterally extending central drive axle driven by an external power source, two pairs of drive sheaves mounted to drive axles, and a means for transmitting rotational energy from the drive sheaves to the drive axles. There are two extended shift arms spaced apart for controlling the positioning of movable drive sheaves. Narrowing or increasing the gap between shift arms, does the same for the gap between the drive sheaves, increasing or decreasing the gear ration respectively which provides speed control. Shifting the shift arms left or right varies the gear ratio between the left and right pair of sheaves, providing differential speed between the left and right driven axles, which provides steering control.

A method for determining a gear ratio (VGR) for a power steering system of a vehicle, said power steering system comprising a steering wheel determining a steering wheel angle (A.sub.v) and a rack determining a rack position (X.sub.c), said rack position (X.sub.c) varying between a lower limit rack position and an upper limit rack position (X.sub.csup), the gear ratio (VGR) defining a ratio between the rack position (X.sub.c) and the steering wheel angle (A.sub.v), or conversely, characterized in that the method comprises a definition step in which the gear ratio (VGR) is defined as a function of a vehicle speed (V1, V2, V3) and of the steering wheel angle (A.sub.v) so that the upper limit rack position (X.sub.csup) corresponds to a single upper limit steering wheel angle (A.sub.vsup).

A method for determining a gear ratio (VGR) for a power steering system of a vehicle, said power steering system comprising a steering wheel determining a steering wheel angle (A.sub.v) and a rack determining a rack position (X.sub.c), said rack position (X.sub.c) varying between a lower limit rack position and an upper limit rack position (X.sub.csup), the gear ratio (VGR) defining a ratio between the rack position (X.sub.c) and the steering wheel angle (A.sub.v), or conversely, characterized in that the method comprises a definition step in which the gear ratio (VGR) is defined as a function of a vehicle speed (V1, V2, V3) and of the steering wheel angle (A.sub.v) so that the upper limit rack position (X.sub.csup) corresponds to a single upper limit steering wheel angle (A.sub.vsup).