Reverse Operation Safety Circuit

• US 20070251737A1
• Filed: 06/15/2007
• Published: 11/01/2007
• Est. Priority Date: 03/09/2005
• Status: Active Grant

• Current Assignee: Delta Systems Inc.
• Original Assignee: Delta Systems Inc.
• Inventors: Wetzel, Ted, Harvey, Arthur, Straka, David
• Granted Patent: US 7,422,078 B2
• Time in Patent Office: Days
• US Class Current: 180/53.600
• CPC Class Codes: A01D 34/828 Safety devices
• CPC Class Codes: B60K 25/06 from the transmission power take-off transmissions having power-take-off B60K17/28
• CPC Class Codes: B60Y 2200/223 Ridable lawn mowers

Abstract

A control circuit for a lawn tractor having an engine and a power take off driven implement. The control circuit includes an inhibit circuit component for preventing operation of a power take off driven implement with the tractor in reverse. Two versions of the inhibit circuit are disclosed, one grounds an engine magneto and a second disables an electric clutch for coupling the power take off to the driven element. The circuit includes first and second override switches and an override circuit component that allows operation of a power take off driven implement while the lawn tractor is in reverse after the first and second override switches are activated in a proper order by a tractor operator.

Claims

1. A control circuit for a lawn tractor having an engine and a power take off driven implement;

said control circuit comprising;

an inhibit circuit component for preventing operation of a power take off driven implement with the tractor in reverse;

first and second override switches; and

an override circuit component that allows operation of a power take off driven implement while the lawn tractor is in reverse after the first and second override switches are activated by a tractor operator.

2. The control circuit of claim 1 wherein the inhibit circuit component prevents operation of the power take off by shutting down the engine.

3. The control circuit of claim 1 wherein the override circuit allows operation of the power take off driven implement if the first and second override switches are activated in a correct order.

4. The control circuit of claim 1 wherein the inhibit circuit has a reverse engagement switch input which changes state when the tractor is shifted into reverse to prevent operation of the power take off driven component.

5. The control circuit of claim 1 wherein the first override switch is coupled to a multi-position ignition switch.

6. The control circuit of claim 5 wherein the second override switch comprises a generally planar layer of conductive material affixed to a flexible membrane that bridges conductive traces on a printed circuit board.

7. The control circuit of claim 1 wherein a low resistance path to ground is created by the inhibit circuit unless the first and second override switches are activated before the tractor is shifted into reverse.

8. The control circuit of claim 1 additionally comprising an operator presence switch that senses an operator, the operator presence switch resetting the override circuit to prevent mowing in reverse.

9. The control circuit of claim 1 additionally comprising a brake engagement switch that senses engagement of a brake, the engagement switch resetting the override circuit to prevent mowing in reverse.

10. The control circuit of claim 1 wherein the engine is a magneto operated engine and the override circuit component prevents the engine from operating by grounding the magneto.

11. The control circuit of claim 1 wherein the override circuit comprises first and second logic circuits that are coupled together and one of said logic circuits produces an override output and wherein one of the first and second override switches changes a logic circuit input state and another of the first and second override switches presents the change in logic state to the override output.

12-22. -22. (canceled)

23. Apparatus for use with a lawn tractor having an engine and a power take off driven implement;

said apparatus comprising;

an inhibit circuit component for preventing operation of a power take off driven implement with the tractor in reverse;

an override switch;

an override circuit component that allows operation of a power take off driven implement while the lawn tractor is in reverse after the override switch is activated by a tractor operator; and

a substrate for supporting said inhibit circuit component, said override switch and the override circuit component.

24. The apparatus of claim 23 additionally comprising an indicator supported by said substrate to indicate a status of the override circuit component.

25. The apparatus of claim 23 comprising a second override switch electrically coupled to the override circuit component and further comprising an ignition actuator that controls a state of the second override switch.

26. The apparatus of claim 25 wherein the ignition actuator is mounted to an ignition module that defines a housing that supports the substrate within a housing interior and mounts to a tractor dashboard.

27. A method for use in controlling operation of a lawn tractor having an engine and a power take off driven implement;

said method comprising;

preventing operation of a power take off driven implement with the tractor in reverse absent an override condition determined by sensing a state of first and second override switches actuatable by a tractor operator;

allowing operation of a power take off driven implement while the lawn tractor is in reverse in an override state after sensing actuation of the first and second override switches by a tractor operator; and

providing a visual indication on the lawn tractor to distinguish between an override and a non override state.

28. The method of claim 27 wherein one of the override switches is coupled to an ignition switch actuator and wherein actuation of said one override switch must occur first before operation of the power take off driven implement is allowed with the tractor in reverse.

29. The method of claim 27 wherein the visual indication of the override state of the lawn tractor is provided by a light emitting device mounted to a substrate which also supports one of said first and second override switches.

30. The method of claim 29 wherein the substrate is supported by an ignition module that includes an ignition switch that defines another of said first and second override switches.

31. Apparatus for use with a lawn tractor having an engine and a power take off driven implement;

said apparatus comprising;

an inhibit circuit component for preventing operation of a power take off driven implement with the tractor in reverse;

an override switch, said override switch comprising a generally planar layer of conductive material affixed to a flexible membrane;

an override circuit component that allows operation of a power take off driven implement while the lawn tractor is in reverse after the override switch is activated by a tractor operator; and

a printed circuit board for supporting said inhibit circuit component and the override circuit component, said printed circuit board comprising a plurality of conductive traces, said conductive traces being selectively bridged by the override switch.