POWER STEERING GEAR ACTUATOR

• US 3,831,701 A
• Filed: 12/07/1972
• Issued: 08/27/1974
• Est. Priority Date: 12/07/1972
• Status: Expired due to Term

• Current Assignee: Howard M. Pilon, Michael M. Schechter, Sven W. Sattavara
• Original Assignee: Howard M. Pilon, Michael M. Schechter, Sven W. Sattavara
• Inventors: Pilon, Howard M., Sattavara, Sven W., Schechter, Michael M.
• Primary Examiner(s): Schonberg, David
• Assistant Examiner(s): Pekar, John A.
• Application Number:
  US05/312,995
• Time in Patent Office: 628 Days
• Field of Search: 180/79.2R 74/388PS 91/367
• US Class Current: 180/407
• CPC Class Codes: B62D 5/008 Changing the transfer ratio between the steering wheel and the steering gear by variable supply of energy, e.g. by using a superposition gear

Abstract

This disclosure relates to a power steering gear, and more particularly to a gear actuator constructed to be controlled both manually and by a source responsive to an external condition such as the lateral force produced upon a vehicle by a cross wind. In accordance with one embodiment, a steering gear actuator has first and second planetary gear sets with an input shaft connected to the sun gear of the first set. The ring gear of the first set is coupled to a power steering valve. The planet gears of the first set are coupled to the planet gears of the second set. An output shaft is connected to both the sun gear of the second set and the ball nut of a power boosted steering gear. An electric motor has a worm gear engaging the ring gear of the second set. The motor is adapted to be actuated by an external system such as a system constructed to produce a signal in response to a lateral force upon the vehicle resulting from a cross wind. Thus, in this embodiment a steering gear actuator is provided having both a manual input and a system operated input. The two planetary gear sets move in response to the two inputs and provide a composite output for actuating the steering gear.

Claims

1. A steering gear actuator constructed to actuate a hydraulic power steering gear unit comprising:

first and second planetary gear sets, each of said sets comprising a sun gear, a ring gear and a planet gear operatively interposed between said sun gear and said ring gear, a manually controlled input shaft connected to said sun gear of said first set, resilient means constructed to resiliently resist angular displacement of said ring gear of said first set, output shaft means connected to said sun gear of said second set, said output shaft means being constructed to be connected to a power steering gear, a planet carrier, said planet gears of said first and second gear sets being coaxially arranged and supported by said planet carrier, auxiliary input means constructed to rotate said ring gear of said second set, said ring gear of said first set being constructed to be displaced in response to the displacement of either said manual input shaft or said auxiliary input means, power steering valve means constructed to sense displacement of said ring gear of said first set and to direct hydraulic fluid to said power steering gear in response to said displacement of said ring gear of said first set.

2. A steering gear actuator according to claim 1 and including:

means constructed to limit the angular displacement of said ring gear of said first set.

3. A steering gear actuator according to claim 2 and including:

means constructed to limit the angular displacement of said ring gear of said second set when said auxiliary input means is inactive.

4. A steering gear actuator according to claim 1 and including:

means constructed to limit the angular displacement of said ring gear of second set when said auxiliary input means is inactive.

5. A steering gear actuator according to claim 1 and including:

said auxiliary input means including a motor, worm gear drive means interconnecting said motor and said ring gear of said second gear set.

6. A steering gear actuator according to claim 1 and including:

said auxiliary input means including a motor, worm gear drive means interconnecting said motor and said ring gear of said second gear set, said worm gear drive means being constructed to transfer motion from said motor to said ring gear of said second gear set, said worm gear drive means being constructed to prevent the rotation of said ring gear of said second set when said motor is inactive.

7. A steering mechanism for a motor vehicle comprising:

a power boosted steering power gear having input means and output means, a steering gear actuator operatively connected to said power steering gear, said steering gear actuator including first and second planetary gear sets, each of said gear sets comprising a sun gear, a ring gear and a planet gear operatively interposed between said sun gear and said ring gear, a manually controlled input shaft connected to said sun gear of said first set, resilient means constructed to resiliently resist angular displacement of said ring gear of said first set, stop means constructed to limit the angular displacement of said ring gear of said first set, power steering valve means constructed to sense displacement of said ring gear of said first set, actuator output shaft means connected to said sun gear of said second set, said output shaft means being connected to said input means of said power steering gear, means supporting said planet gears for rotation about a common axis, auxiliary input means constructed to rotate said ring gear of said second set, hydraulic assist means connected to said output means of said gear and to said power steering valve means, said ring gear of said first set being constructed to be angularly displaced in response to the displacement of both said manual input shaft and said auxiliary input means, said power steering valve being constructed to direct hydraulic pressure fluid to said hydraulic assist means in response to the displacement of said ring gear of said first set.

8. A steering gear actuator according to claim 7 and including:

means constructed to limit the angular displacement of said ring gear of said second set when said auxiliary input means is inactive.