Abstract: The present invention provides a power assist steering system for a vehicle having a wheel. The steering system includes a first reciprocating member coupled to the wheel such that reciprocating movement of the first reciprocating member provides turning movement of the wheel, a steering input engaged with the first reciprocating member such that rotation of the steering input provides reciprocating movement of the first reciprocating member, and a steering assist assembly including a second reciprocating member engaged with the steering input such that reciprocating movement of the second reciprocating member provides an assist force to the steering input. Preferably, the first and second reciprocating members engage the steering input at locations opposed to each other and also move along paths that are substantially parallel to each other.

Abstract: The present invention provides a power assist steering system for a vehicle having a wheel. The steering system includes a first reciprocating member coupled to the wheel such that reciprocating movement of the first reciprocating member provides turning movement of the wheel, a steering input engaged with the first reciprocating member such that rotation of the steering input provides reciprocating movement of the first reciprocating member, and a steering assist assembly including a second reciprocating member engaged with the steering input such that reciprocating movement of the second reciprocating member provides an assist force to the steering input. Preferably, the first and second reciprocating members engage the steering input at locations opposed to each other and also move along paths that are substantially parallel to each other.

Abstract: A hydraulic steering assist assembly is provided for a vehicle with a mechanical steering assembly operable by a user to steer the vehicle. The hydraulic steering assist assembly includes a hydraulic actuator adapted to be coupled to the mechanical steering assembly and has a first side and a second side. A bi-directional hydraulic pump is placed in fluid communication with the first side and the second side of the hydraulic actuator. The hydraulic steering assist assembly further includes a valve in fluid communication with the first side and the second side of the hydraulic actuator, and a control system for controlling the bi-directional hydraulic pump and the valve. The bi-directional hydraulic pump provides a pressurized fluid to the hydraulic actuator, which applies a force on the mechanical steering assembly to assist steering the vehicle. The valve can act as a steering damper.

Abstract: A vehicle steering assembly comprising an input member, an output member, and a torsion bar coupling the input member to the output member. The torsion bar includes primary and secondary load structures, and the secondary load structure is inoperative below a transition torque. The primary load structure includes a primary torque member that constantly couples the input member to the output member throughout an operative range of the steering assembly. The secondary load structure includes first and second torque members that are separated by a gap when the assembly encounters a torque below the transition torque and that contact each other when the assembly encounters a torque above the transition torque. The first torque member can comprise a tubular structure surrounding the primary torque member. The tubular structure includes an opening defining a circumferentially-exposed surface, and the second torque member includes a radially-extending arm positioned in the opening.

Abstract: A hydraulic steering assist assembly is provided for a vehicle with a mechanical steering assembly operable by a user to steer the vehicle. The hydraulic steering assist assembly includes a hydraulic actuator adapted to be coupled to the mechanical steering assembly and has a first side and a second side. A bi-directional hydraulic pump is placed in fluid communication with the first side and the second side of the hydraulic actuator. The hydraulic steering assist assembly further includes a valve in fluid communication with the first side and the second side of the hydraulic actuator, and a control system for controlling the bi-directional hydraulic pump and the valve. The bi-directional hydraulic pump provides a pressurized fluid to the hydraulic actuator, which applies a force on the mechanical steering assembly to assist steering the vehicle. The valve can act as a steering damper.