Patent ID: 7389849
Filing Date: 2008-06-24
Classification: B62D

Abstract:
1. An apparatus for use in turning first and second steerable vehicle wheels of a vehicle in response to manual rotation of a steering wheel, said apparatus comprising: a first cylinder type hydraulic motor connected with the first steerable vehicle wheel and with a central portion of the vehicle, a second cylinder type hydraulic motor connected with the second steerable vehicle wheel and with the central portion of the vehicle, a steering control valve which is connected in fluid communication with said first and second hydraulic motors, said steering control valve being operable in response to manual rotation of the steering wheel in one direction to enable fluid to flow to the first hydraulic motor to effect contraction of the first hydraulic motor and to enable fluid to flow from the second hydraulic motor to effect expansion of the second hydraulic motor, said steering control valve being operable in response to manual rotation of the steering wheel in a direction opposite to the one direction to enable fluid to flow from the first hydraulic motor to effect expansion of the first hydraulic motor and to enable fluid to flow to the second hydraulic motor to effect contraction of the second hydraulic motor, a pinion connected with said steering control valve, and an array of rack teeth connected with said first hydraulic motor, said pinion being disposed in meshing engagement with said array of rack teeth and being rotatable by said array of rack teeth upon operation of said first hydraulic motor.