# US 5,343,675 A · Motion sensing safety interlock

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- Number: US 5,343,675 A
- Document ID: US5343675A
- Status: Granted
- Kind: A
- Application number: 07/721,298
- Filed: 1991-06-26
- Granted: 1994-09-06
- Earliest claimed: 1991-06-26
- Assignees: Vermeer Manufacturing Company
- Inventors: Louis Norton
- Web page: https://patentgrep.com/patent/US5343675A

## CPC

- B62D 49/065: {Coupling of multi-purpose tractors with equipment (towing bars B60D; with load transfer B62D53/08; power take-off B60K; with lifting devices B62D49/02; pushing gear B62D49/04)}
- A01D 41/1274: {for drives}
- Y10S 56/15: Condition responsive
- 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)
- A01D: HARVESTING; MOWING
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A motion sensing safety interlock which disables one or more equipment elements of a ground-traveling machine upon stopping or slowing of the machine below a preselected ground speed. A speedometer cable interconnects a wheel of the machine and a monitor box in which is mounted for rotation by the cable a ferrous star wheel. Lobes of the star wheel pass between poles of a magnetic reed switch which changes state at a frequency corresponding to the rotational speed of the wheel. Electrical circuitry monitors the reed switch and disengages an electric clutch to stop the equipment elements upon the stopping of ground travel of the machine.

## Claims

### Claim 1

A motion sensor and safety controller for controlling the operation of an equipment element of a ground-traveling machine, comprising:
(a) ground-engaging rotary means for generating a signal in response to movement of the machine over the ground;
(b) means for monitoring said signal;
(c) switch means controlled by said monitor means for interrupting the operation of the equipment element when movement of the machine drops below a preselected speed for a preselected time.

### Claim 2

A motion sensor and safety controller for controlling the operation of an equipment element of a ground-traveling machine, comprising:
(a) an axially centered hub rotated upon movement of the equipment over the ground;
(b) ground-engaging rotary means for generating a signal and response to movement of the machine over the ground.
(c) means for monitoring said signal;
(d) cable means interconnecting said hub and said monitor means; and
(e) switch means controlled by said monitor means for interrupting the operation of the equipment element when movement of the machine drops below a preselected speed.

### Claim 3 (depends on 2)

A controller as defined in claim 2 wherein the machine includes at least one stub axle having an axial throughbore in which is received said cable means.

### Claim 4

A motion sensor and safety controller for controlling the operation of an equipment element of a ground-travelling machine, comprising:
(a) ground-engaging rotary means for generating a signal in response to movement of the machine over the ground;
(b) signal monitoring means having a magnetic reed switch, a ferrous member mounted for rotation in response to said signal, and means connected to said magnetic reed switch for changing the state of said switch means upon a drop in the rate of rotation of said ferrous member below a preselected level; and
(c) switch means controlled by said monitor means for interrupting the operation of the equipment element when movement of the machine drops below a preselected speed.

### Claim 5

A motion sensor and safety controller for controlling the operation of an equipment element of a ground-travelling machine, comprising:
(a) a first ground-engaging rotary means for generating a signal in response to movement of the machine over the ground;
(b) a second ground-engaging rotary means mounted distally to said first ground-engaging rotary means and laterally relative to said first ground-engaging rotary means plane of rotation;
(c) signal monitoring means having a magnetic reed switch, a ferrous member mounted for rotation in response to said signal, and means connected to said magnetic reed switch for changing the state of said switch means upon a drop in the rate of rotation of said ferrous member below a preselected level; and
(d) switch means controlled by said monitor means for interrupting the operation of the equipment element when movement of the machine drops below a preselected speed.