Vegetation cutting device

Patent metadata

Field	Value
Publication number	US-9730384-B2
Application number	US-201314062111-A
Country	US
Kind code	B2
Filing date	Oct 24, 2013
Priority date	Oct 26, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A vegetation cutting device comprising a housing rotatably coupled to a shaft; a cutting head comprising a rotary cutting device for cutting vegetation, the cutting head being coupled to the shaft and being arranged to move between an edging mode in which the rotary cutting device rotates in a substantially horizontal plane; a motor mounted in the housing, the motor being arranged to drive the rotary cutting device; and a switching device mechanically coupled between the housing and the shaft and arranged to be actuated when the shaft rotates relatives to the housing thereby changing the speed of the rotary cutting device when the cutting head moves between the edging mode and trimming mode.

First claim

The invention claimed is:

1. A vegetation cutting device comprising:
a housing rotatably coupled to a shaft;
a cutting head comprising a rotary cutting means for cutting vegetation, the cutting head being coupled to the shaft and being arranged to move between an edging mode in which the rotary cutting means rotates in a substantially vertical plane and a trimming mode in which the rotary cutting means rotates in a substantially horizontal plane;
a motor mounted in the housing, the motor being arranged to drive the rotary cutting means; and
a switching means mechanically coupled between the housing and the shaft and arranged to be actuated when the shaft rotates relative to the housing thereby changing the speed of the rotary cutting means when the cutting head moves between the edging mode and trimming mode; and
wherein the switching means comprises a switch mounted on one of the housing or the shaft and an actuating element for actuating the switch mounted on the other of the housing or the shaft.

2. The vegetation cutting device according to claim 1 wherein the shaft rotates about a longitudinal axis of the shaft with respect to the housing.

3. The vegetation cutting device according to claim 1 wherein the actuating element is a camming surface for engaging with a moveable switch element of the switch and for moving the moveable switch element between a first position and a second position.

4. The vegetation cutting device according to claim 3 wherein the moveable switch element is biased to one of the first position and the second position.

5. The vegetation cutting device according to claim 1 wherein the cutting head is fixed with respect to one end of the shaft and the housing is rotatably coupled to another end of the shaft.

6. The vegetation cutting device according to claim 1 wherein the switching means is configured to change a voltage supplied to the motor and change the speed of the motor.

7. The vegetation cutting device according to claim 6 wherein the switching means is configured to change between a first circuit arrangement for supplying a first voltage to the motor when the cutting head is in the trimming mode and a second circuit arrangement for supplying a second voltage to the motor when the cutting head is in the edging mode and the first voltage is greater than the second voltage.

8. The vegetation cutting device according to claim 7 wherein the second circuit arrangement comprises a half-wave rectifying circuit and the first circuit arrangement shorts out the half-wave rectifying circuit.

9. The vegetation cutting device according to claim 8 wherein half-wave rectifying circuit comprises a diode.

10. The vegetation cutting device according to claim 6 wherein the switching means comprises a pulse width modulation controller configured to change a voltage duty cycle supplied to the motor when the switching means is actuated.

11. The vegetation cutting device according to claim 1 wherein the switching means is configured to be actuated when cutting head is rotated approximately half way between the edging mode and the trimming modes.

12. A vegetation cutting device comprising:
a housing;
a cutting head comprising a rotary cutting element for cutting vegetation;
a shaft coupling the cutting head to the housing, the cutting head being arranged to move between an edging mode in which the rotary cutting element rotates in a substantially vertical plane and a trimming mode in which the rotary cutting element rotates in a substantially horizontal plane;
a motor being arranged to drive the rotary cutting element; and
a switch for detecting whether the cutting head is in the edging mode or the cutting mode, and operating the motor at a first speed in the edging mode and a second speed when in the trimming mode.

13. The vegetation cutting device of claim 12 , wherein movement of the cutting head between the edging mode and the trimming mode automatically actuates the switch to change the speed of the motor.

14. The vegetation cutting device of claim 12 , wherein the first speed is lesser than the second speed.

15. The vegetation cutting device of claim 12 , wherein the rotation of the cutting head between the edging mode and trimming mode moves a cammed surface to actuate the switch.

16. A method of changing the motor speed of a vegetation cutting device comprising the steps of:
providing the vegetation cutting device of claim 1 ;
moving the cutting head from the trimming mode to the edging mode, wherein the movement of the cutting head actuates the switching means for changing the motor speed.

Assignees

• Black & Decker Inc

Inventors

• Proudlock David
• Walmsley Neil

Classifications

• A01D34/90

  for carrying by the operator · CPC title

• A01D34/826 Primary

  Noise reduction means · CPC title

• A01D34/84

  for edges of lawns or fields, e.g. for mowing close to trees or walls ({for embankments A01D34/86 takes precedence;} edge trimmers A01G3/00) · CPC title

• A01D34/412 Primary

  having rotating cutters · CPC title

• Y10T83/9495

  Nonparallel cutting edges · CPC title