Hybrid electric lawnmower

• US 20080120955A1
• Filed: 09/05/2007
• Published: 05/29/2008
• Est. Priority Date: 10/17/2006
• Status: Abandoned Application

• Current Assignee: Mtd Products Incorporated (Stanley Black & Decker, Inc.)
• Original Assignee: Mtd Products Incorporated (Stanley Black & Decker, Inc.)
• Inventors: Lucas, Delbert R., Lucas, Justin, Lucas, Ryan Jay
• Application Number:
  US11/899,616
• Publication Number:
  US 20080120955A1
• Time in Patent Office: Days
• US Class Current: 56/10.6
• CPC Class Codes: A01D 34/78 electric
• CPC Class Codes: A01D 69/025 Electric hybrid systems

Abstract

A hybrid electric lawnmower is described which includes a hybrid mower able to operate on two differing DC voltages. The mower presently described includes a hybrid controller operable to drive a permanent magnet electric motor on a high voltage and a low voltage wherein the operating may select either DC or AC operation representing the low voltage or high voltage. The dual voltage motor has separate windings on the rotor, both of the windings operable to drive the motor whether selected to operate on DC or on AC. The user operable selection of AC or DC reconfigures the dual windings on the rotor in either series or parallel configuration wherein low voltage operation places the windings in parallel relationship and high voltage operation places the windings in series relationship.

Claims

1. A hybrid mower for operation in AC or DC mode, comprising:

a permanent magnet motor mounted to a mower housing and turning a blade, said motor controlled by a hybrid controller, said controller having a user selection switch of low voltage and high voltage;

said motor having a first coil electrically separated from a second coil, both of said first and said second coil wrapped on a rotor of said motor;

a hybrid controller including a user selection switch selectively connecting said motor to a battery pack and to a high voltage DC source, said high voltage DC source about double the voltage provided by said batter pack;

wherein said motor includes a first commutator in electrical contact with said first coil and a second commutator in electrical contact with said second coil, said first and said second commutator on opposite ends of said rotor and being in contact with first and second brushes;

said user selection switch operable to electrically connect said first coil and said second coil in a first series connection and in a second parallel connection.

2. The mower of claim 1 wherein said user selection switch is a three pole double throw switch selectively connecting said motor to said high voltage power supply or to a lower voltage power supply.

3. The mower of claim 1 wherein said high voltage DC source is rectified from 120V AC.

4. The mower of claim 1 further comprising an interlock handle switch positioned on said mower, said interlock handle switch electrically interposed between said user selection switch and said first and said second coil to inactivate said motor when said switch is open.

5. An electric lawn mower operable to run from AC line voltage and lower voltage DC, comprising:

a mower having a mower deck and an electric motor mounted on said deck and turning a blade;

selection switch switchable between AC and DC operation;

wherein said motor has a first coil electrically separated from a second coil, said first coil in electrical contact with a first commutator, said second coil in electrical contact with a second commutator, said first and second commutator being in contact with first and second brushes;

said user selection switch operable to electrically connect said first coil in series with said second coil when placed in a first position, and operable to electrically connect said first coil in parallel with said second coil when placed in a second position.

6. The electric lawn mower of claim 5 wherein said user selection switch is a triple pole double throw switch.

7. The electric lawn mower of claim 6 wherein said motor is placed in electrical connectivity to a high voltage DC source when said user selection switch is placed in first orientation and wherein said motor is placed in electrical connectivity to a lower voltage DC source when said user selection switch is placed in a second orientation.

8. The electric lawn mower of claim 7 wherein said high voltage DC source is a rectified 120V AC.

9. The electric lawn mower of claim 7 wherein said lower voltage source is a batter pack.

10. The electric lawn mower of claim 9 wherein said battery pack has about 60 VDC potential.

11. A dual voltage electric lawn mower comprising:

a dual voltage electric motor mounted to a mower housing and connected to a user selection switch mounted on said mower;

a blade rotating on said housing and connected to said electric motor;

a battery pack and an AC input line in electrical connectivity with said user selection switch;

said dual voltage motor having a first set of windings and a second set of windings on an armature and in electrical connectivity with said user selection switch;

setting configuring said first and said second set of windings in parallel relationship, said second setting configuring said first and said second set of windings in series relationship.

12. A dual voltage electric lawn mower, comprising:

an electric mower having a dual voltage electric motor powering a blade on a housing;

first and second windings on said motor;

switch circuit means configuring said first and second windings in a first parallel relationship when in a first position and in a second series relationship when in a second position;

a high voltage source connected to said motor when said switch means is in said second position;

a low voltage source connected to said motor when said switch means is in said first position.

13. The mower of claim 12 wherein said switch circuit means includes a triple pole double throw switch.

14. The mower of claim 13 wherein said low voltage source is a batter pack.

15. The mower of claim 13 wherein said high voltage source is 120V AC.