# US 4,391,340 A · Dither assisted steering

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- Number: US 4,391,340 A
- Document ID: US4391340A
- Status: Granted
- Kind: A
- Application number: 06/231,399
- Filed: 1981-02-04
- Granted: 1983-07-05
- Earliest claimed: 1981-02-04
- Inventors: John Z. DeLorean
- Web page: https://patentgrep.com/patent/US4391340A

## CPC

- B62D 5/00: Power-assisted or power-driven steering (for non-deflectable wheels B62D11/00; fluid-pressure servomotors in general F15B)
- B62D 15/00: Steering not otherwise provided for
- Y10T 74/18344: Unbalanced weights
- B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

In order to reduce steering effort in an automobile at low speeds, without excessive power consumption, a low amplitude dither is introduced into the steering linkage to break away the friction between the tires and road surface.

## Claims

### Claim 1

A method of reducing steering effort at low speeds in a mechanical steering system in an automobile, including a steering linkage coupling a steering wheel to wheels having tires thereon, comprising introducing into the steering linkage a low amplitude dither so as to break away the friction normally existing between tire and roadway.

### Claim 2 (depends on 1)

The method of claim 1 and further comprising selecting the frequency of said dither to be equal to a natural resonant frequency of the steering system.

### Claim 3

In combination with a steering system linkage coupling a steering wheel to wheels having tires thereon, apparatus for reducing steering effort at low speeds by introducing a low amplitude dither into the steering linkage, comprising:
(a) means including an oscillating system attached to the steering linkage; and
(b) means to input energy to said oscillating system.

### Claim 4 (depends on 3)

Apparatus according to claim 3 wherein said oscillating system comprises an oscillating mass.

### Claim 5 (depends on 4)

Apparatus according to claim 4 wherein said oscillating system comprises:
(a) a frame;
(b) first and second gears engaging each other supported for rotation in said frame; and
(c) an eccentric weight disposed on each of said gears.

### Claim 6 (depends on 3)

Apparatus according to claim 3 wherein said means for coupling energy comprises an electric motor.

### Claim 7 (depends on 3)

Apparatus according to claim 3 and wherein said means for coupling energy comprises means to couple said system to a rotating component in the automobile in which the steering linkage is to be installed.

### Claim 8 (depends on 3)

Apparatus according to claim 3, wherein said means for coupling energy comprises an auxiliary internal combustion engine.

### Claim 9 (depends on 3)

Apparatus according to claim 3 wherein said means for coupling comprises a flexible cable adapted to be disposed between said oscillating system and said rotating component.

### Claim 10 (depends on 3)

Apparatus according to claim 3 and further including means operable to cause said means for coupling energy to couple energy to said vibrating system only at low vehicle speeds.

### Claim 11 (depends on 10)

Apparatus according to claim 10 wherein said means to cause comprises a speed sensor and means to interrupt the supply of energy when a vehicle speed above a predetermined amount is sensed.

### Claim 12 (depends on 3)

Apparatus according to claim 3 and further including means to attach said oscillating system to the steering linkage whereby said system may be added on to existing automobiles.