Mower responsive to backup sensor

• US 20060042212A1
• Filed: 08/31/2004
• Published: 03/02/2006
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Shoemaker, Jim Milton, Hunt, Kenneth Edward, Hahn, Robert W., Hough, Barry Michael
• Granted Patent: US 7,224,088 B2
• Time in Patent Office: Days
• US Class Current: 56/10.20R
• CPC Class Codes: A01D 34/828 Safety devices
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles

Abstract

An interlock circuit on a mowing vehicle or tractor deactivates the engine if a signal from a single backup sensor is interrupted. The mowing vehicle or tractor has an engine, an electric power source to provide electric current to a magneto and an ignition, a transmission connected to the engine and having forward, neutral and reverse operations, a controllable tool drive (PTO) connected to the engine for powering an accessory, and a single backup sensor to provide a signal if no object is detected behind the vehicle. A reverse sensing switch is movable between a first position if the transmission is in forward or neutral, and a second position if the transmission is in reverse. A PTO switch is movable between an on condition for activating the PTO and an off position for deactivating the PTO.

Claims

1. An interlock circuit on a mowing vehicle having an engine, an electric power source to provide electric current to a magneto and an ignition, a transmission connected to the engine and having forward, neutral and reverse operations, a controllable tool drive (PTO) connected to the engine for powering an accessory, and a single backup sensor to provide a signal if no object is detected behind the vehicle, the interlock circuit comprising:

a reverse sensing switch movable between a first position if the transmission is in forward or neutral, and a second position if the transmission is in reverse;

a PTO switch connected to the PTO, the PTO switch movable between an on condition for activating the PTO and an off position for deactivating the PTO;

the interlock circuit grounding the magneto and the ignition if a signal from the single backup sensor is interrupted while the reverse sensing switch in the second position and the PTO switch is in the on condition.

2. The interlock circuit of claim 1 wherein the electric current from the electric power source to the magneto and to the ignition may be switched on by shifting the transmission to forward or neutral after the signal from the single backup sensor is interrupted.

3. The interlock circuit of claim 1 wherein the PTO switch has a momentary on position to switch on electric current from the electric power source to the magneto and to the ignition after the signal from the single backup sensor is interrupted.

4. The interlock circuit of claim 1 further comprising a delay circuit to delay the time to switch off electric current to the magneto.

5. In a lawn and garden vehicle having an operator station, a ground drive for providing vehicle drive and non-drive conditions including a selector for selecting either forward or reverse vehicle operation, a controllable tool drive (PTO) for powering an accessory, and an interlock circuit, the interlock circuit comprising:

a PTO switch connected to the PTO, the PTO switch movable to an on condition for activating the PTO, and to an off condition for deactivating the PTO;

a reverse sensing switch connected to the PTO and the PTO switch and responsive to the selection of reverse vehicle operation; and

a backup sensor switch connected to the PTO switch and reverse sensing switch for selectively halting operation of the ground drive if an object is detected behind the vehicle while the PTO is activated during reverse vehicle operation.

6. The interlock circuit of claim 5 wherein the backup sensor switch provides a non-intrusion signal if no object is detected behind the vehicle while the PTO is activated during reverse vehicle operation.

7. The interlock circuit of claim 5 further comprising an operator presence switch to halt operation of the ground drive if an operator is not detected on the vehicle.

8. The interlock circuit of claim 5 wherein the PTO switch further comprises a position to bypass the backup sensor switch.

9. An interlock circuit on a tractor having an engine and a transmission shiftable between forward, neutral and reverse, comprising:

a backup sensor switch having a first position indicating the absence of an object behind the tractor and a second position indicating the presence of an object behind the tractor;

a PTO switch connected to the backup sensor switch and having an off position for deactivating a controllable tool drive (PTO), and an on position for activating the PTO, the PTO switch bypassing the backup sensor switch if the PTO is deactivated; and

a reverse sensing switch connected to the PTO switch and backup sensor switch to bypass the backup sensor switch if the tractor transmission is in forward or neutral.

10. The interlock circuit of claim 9 wherein the backup sensor switch deactivates the engine in the second position.

11. The interlock circuit of claim 9 further comprising a magneto relay and a magneto, the backup sensor switch grounding the magneto in the second position.

12. The interlock circuit of claim 9 further comprising a brake switch movable between a brake on position and brake off position;

and an operator presence switch connected to the brake switch, the operator presence switch having a first position indicating the presence of an operator and a second position indicating the absence of an operator;

the operator presence switch deactivating the engine in the second position if the brake switch is on.