US 5,288,091 AGranted

Four wheel steering apparatus

AssigneeNoma Outdoor Products, Inc.

InventorJoe Deschamps

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Abstract

A four wheel steering system for a vehicle which significantly reduces or eliminates scrubbing of the outside tires. A preferred embodiment is specially adapted for use on riding lawn mowers, and includes a longitudinally moveable cam plate having a pair of cam slots formed therein, each slot engaging an individual steering arm for separately steering each rear wheel. The cam plate is coupled to a sector gear which reciprocates in response to left and right hand movement of a steering wheel, with the sector gear interconnecting the front and rear wheel steering mechanisms. The slots in the cam plate are specially configured to vary the turning angles of the rear wheels so that the wheels turn through varying angles, thereby reducing scrubbing to an acceptable level. In a preferred embodiment, all four wheels may be calibrated to turn about a single point, thereby completely eliminating scrubbing.

Claims14

Dependent claims

Apparatus for controlling the steering of the front and rear wheels of a four-wheeled vehicle in response to movement of a steering input member, wherein laterally opposed wheels comprise inside and outside wheels during turning of said vehicle, said apparatus comprising:

interconnecting means, operatively connected to said steering input member and rotatable in response to movement thereof;
front wheel steering means having at least one front link assembly attached to said front wheels and said interconnecting means, said front link assembly being adapted to translate rotational movement of said interconnecting means into pivotal movement of said front wheels;
and
rear wheel steering means comprising a pair of rear link assemblies independently connected to each of said rear wheels, each of said rear link assemblies having a steering arm with a first end operatively communicating with said interconnecting means and moveable in response to rotation thereof, and a second end connected to a tie rod assembly, said tie rod assembly being connected to one of said rear wheels wherein lateral movement of said tie rod assembly effects pivotal movement of said rear wheel;
wherein
rotation of said interconnecting means is translated into angular movement of said rear wheels by said rear wheel steering means such that, during at least a portion of the total angular movement of said rear wheels, the angular movement of said inside wheel is not equivalent to the angular movement of said outside wheel, thereby reducing slippage of said rear wheels relative to the ground.

3 more elements

Apparatus for steering at least two wheels of a multi-wheeled vehicle, said vehicle having a steering input member and a generally horizontal frame with first and second laterally spaced wheels operatively secured thereto, said first and second wheels being angularly pivotal about substantially vertical axes, said apparatus comprising:

a reciprocating member engaging said steering input member and operative to move in response to movement thereof;
a link having a first end secured to said reciprocating member and a second end extending therefrom, operative to move substantially longitudinally upon movement of said reciprocating member;
a plate member attached to said second end of said link, slidably mounted to said frame and longitudinally moveable upon movement of said link, said plate member having at least one longitudinal contoured slot formed therein;
and
first and second steering arms each having a first end portion engaging said at least one slot, operatively connected to said first and second wheels whereby said wheels pivot angularly in response to lateral movement of said steering arms, wherein
said at least one slot is adapted to drive said steering arms laterally in response to longitudinal movement of said plate member, thereby steering said first and second wheels.

3 more elements

Dependencies are inferred from the claim text.