Four-wheel steering system
First Claim
1. In an automotive vehicle, a four-wheel steering system comprising:
- a front steering gear for steering a pair of front wheels of said vehicle in response to rotation of a steering wheel of said vehicle and including a rear steer control shaft rotatable about a first axis of said vehicle in a direction corresponding to the direction of rotation of said steering wheel and at a predetermined ratio relative to said steering wheel rotation,a rear steering gear for steering a pair of rear wheels of said vehicle in response to rotation of a rear pinion shaft of said rear steering gear about a second axis of said vehicle parallel to and spaced from said first axis,means defining a housing on said vehicle into which each of said control shaft and said rear pinion shaft extends,a gear on said rear pinion shaft within said housing rotatable as unit with said rear pinion shaft,a gear sector meshing with said gear on said rear pinion shaft and supported on said housing for rotation about a third axis parallel to each of said first and said second axes,said second and said third axes being disposed in a common plane containing said first axis and on opposite sides of said first axis,means on said gear sector defining a track extending radially relative to said third axis,a crank assembly on said control shaft within said housing rotatable as a unit therewith about said first axis having a wrist pin assembly thereon movable radially relative to said first axis through a plurality of eccentric positions relative to said first axis from a null position on said first axis,a connecting means on said wrist pin assembly received in said track on said gear sector and slidable therealong so that said gear sector rotates in a negative steer phase direction when said wrist pin assembly is displaced in a negative phase direction relative to said first axis from said null position and rotates in a positive steer phase direction when said wrist pin assembly is displaced in a positive phase direction relative to said first axis from said null position, andcontrol means operative to selectively locate said wrist pin assembly in one of said null position and said plurality of eccentric positions displaced from said null position.
1 Assignment
0 Petitions
Accused Products
Abstract
In a four-wheel steering system for automotive vehicles of the type having a front rack and pinion steering gear of the front wheels and a rear rack and pinion steering gear for the rear wheels, a gear box is disposed between the control shaft from the front steering gear and the pinion shaft of the rear steering gear. A crank assembly having a variable eccentricity wrist pin is disposed on the end of the control shaft within the gear box. The wrist pin is slidably received in a track on a gear sector in the gear box. The gear sector meshes with a spur gear on the end of the rear pinion shaft within the gear box. In a null position of the wrist pin, the latter is on the axis of rotation of the control shaft so that no rear steering occurs. When the wrist pin is moved from the null position and the control shaft rotated, the gear sector is pivoted in a direction corresponding to the direction of displacement of the wrist pin thereby to rotate the spur gear and steer the rear wheels.
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Citations
6 Claims
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1. In an automotive vehicle, a four-wheel steering system comprising:
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a front steering gear for steering a pair of front wheels of said vehicle in response to rotation of a steering wheel of said vehicle and including a rear steer control shaft rotatable about a first axis of said vehicle in a direction corresponding to the direction of rotation of said steering wheel and at a predetermined ratio relative to said steering wheel rotation, a rear steering gear for steering a pair of rear wheels of said vehicle in response to rotation of a rear pinion shaft of said rear steering gear about a second axis of said vehicle parallel to and spaced from said first axis, means defining a housing on said vehicle into which each of said control shaft and said rear pinion shaft extends, a gear on said rear pinion shaft within said housing rotatable as unit with said rear pinion shaft, a gear sector meshing with said gear on said rear pinion shaft and supported on said housing for rotation about a third axis parallel to each of said first and said second axes, said second and said third axes being disposed in a common plane containing said first axis and on opposite sides of said first axis, means on said gear sector defining a track extending radially relative to said third axis, a crank assembly on said control shaft within said housing rotatable as a unit therewith about said first axis having a wrist pin assembly thereon movable radially relative to said first axis through a plurality of eccentric positions relative to said first axis from a null position on said first axis, a connecting means on said wrist pin assembly received in said track on said gear sector and slidable therealong so that said gear sector rotates in a negative steer phase direction when said wrist pin assembly is displaced in a negative phase direction relative to said first axis from said null position and rotates in a positive steer phase direction when said wrist pin assembly is displaced in a positive phase direction relative to said first axis from said null position, and control means operative to selectively locate said wrist pin assembly in one of said null position and said plurality of eccentric positions displaced from said null position. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification