Grass trimmer

• US 4,823,464 A
• Filed: 09/14/1987
• Issued: 04/25/1989
• Est. Priority Date: 09/14/1987
• Status: Expired due to Fees

• Current Assignee: Textron Inc
• Original Assignee: Textron Inc
• Inventors: Gorski, John W.
• Primary Examiner(s): Watts, Douglas D.
• Application Number:
  US07/095,634
• Time in Patent Office: 589 Days
• Field of Search: 30/276, 30/347, 30/388-391
• US Class Current: 30/276
• CPC Class Codes: A01D 34/4167 Protection devices
• CPC Class Codes: A01G 3/062 Motor-driven edge trimmers

Abstract

A shield for a string trimmer using a rotating flexible cutting element defining a circular perimeter including:

a base wall generally parallel to the plane of the rotating cutting element and having a rear portion; and

an arcuate rim member extending downwardly from a portion of the base wall, the rim member and the perimeter defining a pair of oppositely directed volute pathways each terminating in an opening, each of said pathways having a minimum width adjacent to the rear portion of the base wall which gradually increases in width from the rear portion to the opening.

Claims

1. A shield for a string trimmer using a rotating flexible cutting element defining a circular perimeter comprising:

a base wall generally parallel to the plane of the rotating cutting element and having a rear portion; and

an arcuate rim member extending downwardly from a portion of the base wall, said rim member and said perimeter defining a pair of oppositely directed volute pathways each terminating in an opening, each of said pathways having a minimum width adjacent to the rear portion of the base wall which gradually increases in width from the rear portion to the opening.

2. The shield of claim 1 further comprising a guard member extending downwardly from a portion of the base wall adjacent said perimeter.

3. The shield of claim 2 further comprising a cutting blade disposed upon said guard member adjacent said perimeter whereby excess cutting element is removed thereby.

4. An apparatus for cutting vegetation and the like comprising:

a housing;

a motor means associated with said housing;

a hub member coupled to said motor and driven rotatably thereby;

a flexible cutting element attached to said hub member and extending radially outwardly therefrom and rotatable therewith to form a circular cutting plane generally perpendicular to the axis of rotation of said hub member; and

a shield member attached to said housing;

said shield member comprising;

a base wall generally parallel to said cutting plane and having an aperture therein throughwhich said hub member extends;

said base wall having a generally forward portion held away from the operator and a generally rearward portion held toward the operator;

an arcuate rim member disposed about the rear portion of said base wall;

said arcuate rim member extending downward beyond the circular cutting plane of said flexible element and circumferentially about a portion of the perimeter defined by said circular cutting plane;

said arcuate member and said perimeter defining a pair of oppositely directed gradually widening volute pathways each terminating in an opening whereby rotation of said flexible element cooperates with said openings and said pathways to direct cut vegetation into one opening and discharge it from the other opening toward the front portion of said base wall and away from the operator.

5. An apparatus for cutting vegetation and the like comprising:

a housing;

a motor means mounted in said housing;

a hub member coupled to said motor and driven rotatably thereby;

a flexible cutting element attached to said hub member and extending radially outwardly therefrom and rotatable therewith to form a circular cutting plane generally perpendicular to the axis of rotation of said hub member;

a shield member attached to said housing;

said shield member comprising;

a base wall generally parallel to said cutting plane and having an aperature therein throughwhich said hub member extends;

said base wall having a generally forward portion held away from the operator and a generally rearward portion held toward the operator;

an arcuate rim member disposed about the rear portion of said base wall;

said arcuate rim member extending downwardly beyond the circular cutting plane of said flexible element and circumferentially about a portion of the perimeter defined by said circular cutting plane;

said arcuate member being spaced from said perimeter and defining a pathway therebetween having a minimum width area adjacent the most rearward portion of said base wall and gradually increasing in width therefrom circumferentially laterally about each side of said perimeter and terminating in end members adjacent the forward portion of said base wall to form a pair of openings with each said end member being at a relative maximum distance from said perimeter whereby rotation of said flexible element cooperates with said openings and said pathway to direct cut vegetation into one opening and discharge it from the other opening toward the front portion of said base wall and away from the operator; and

a guard member disposed upon the front portion of said base wall and depending therefrom adjacent the perimeter of said cutting element.

6. The apparatus in accordance with claim 5 further comprising a cutting blade disposed upon said guard member adjacent the perimeter of said cutting plane whereby excess cutting element is removed thereby.

7. The apparatus in accordance with claim 5 wherein said hub member includes a cutting element metering device.

8. The apparatus in accordance with claim 5 wherein said shield member is formed of plastic material.

9. The apparatus in accordance with claim 5 wherein said shield member is formed of sheet metal.

10. An apparatus for cutting vegetation and the like comprising:

a housing;

a motor means mounted in said housing;

a hub member coupled to said motor and driven rotatably thereby;

a flexible cutting element attached to said hub member and extending radially outwardly therefrom and rotatable therewith to form a circular cutting plane generally perpendicular to the axis of rotation of said hub member;

a shield member attached to said housing;

said shield member comprising;

a base wall generally parallel to said cutting plane and having an aperture therein throughwhich said hub member extends;

said base wall having a generally forward portion held away from the operator and a generally rearward portion held toward the operator;

an arcuate rim member disposed about the rear portion of said base wall;

said arcuate rim member extending downwardly beyond the circular cutting plane of said flexible element and circumferentially about a portion of the perimeter defined by said circular cutting plane;

said arcuate member being spaced from said perimeter and defining a pathway therebetween having a minimum width area adjacent the most rearward portion of said base wall and gradually increasing in width therefrom circumferentially laterally about each side of said perimeter and terminating in end members adjacent the forward portion of said base wall to form a pair of openings with each said end member being at a relative maximum distance from said perimeter whereby rotation of said flexible element cooperates with said openings and said pathway to direct cut vegetation into one opening and discharges it from the other opening toward the front portion of said base wall and away from the operator;

a guard member disposed upon the front portion of said base wall and depending therefrom adjacent the perimeter of said cutting element; and

a cutting blade disposed upon said guard member adjacent the perimeter of said cutting plane whereby excess cutting element is removed thereby.

11. The apparatus in accordance with claim 10 wherein said arcuate rim member defines a circle having a radius of length A and said circular cutting plane has a radius of length B whereby A minus B equals length C;

and said distance between each said end member and the adjacent perimeter of said circular cutting plane has a length D whereby the relationship of said lengths A,B,C, and D is A minus B equals C equals D to thereby form a suitable pathway between said perimeter and said arcuate rim member.

12. In a string trimmer apparatus for cutting vegetation and the like including:

a housing;

a motor means;

a hub member coupled to said motor and driven rotatably thereby;

a flexible cutting element attached to said hub member and extending radially outwardly therefrom and rotatable therewith to form a curcular cutting plane generally perpendicular to the axis of rotation of said hub member;

the improvement characterized by a shield member attached to said housing;

said shield member comprising;

a base wall generally parallel to said cutting plane and having an aperture therein throughwhich said hub member extends;

said base wall having a generally forward portion held away from the operator and a generally rearward porton held toward the operator;

an arcuate rim member disposed about the rear portion of said base wall;

said arcute rim member extending downwardly beyond the circular cutting plane of said flexible element and circumferentially about a portion of the perimeter defined by said circular cutting plane;

said arcuate member being spaced from said perimeter and defining a pathway therebetween having a minimum width area adjacent the most rearward portion of said base wall and gradually increasing in width therefrom circumferentially laterally about each side of said perimeter and terminating in end members adjacent the forward portion of said base wall to form a pair of openings with each said end member being at a relative maximum distance from said perimeter whereby rotation of said flexible element cooperates with said openings and said pathway to direct cut vegetation into one opening and discharge it from the other opening toward the front portion of said base wall and away from the operator.

13. A shield for a grass trimmer comprising:

a shield member defined by a base member and a circular rim member, said circular rim member having a radius "A" from a first center; and

a flexible rotating cutting element defining a circular perimeter having a radius "B" smaller than radius "A" and a center of rotation, said center of rotation being displaced rearward from the first center toward the rim member thereby defining oppositely directed volute pathways between the circular rim and the circular perimeter.

14. A trimmer as defined in claim 13 where the cutting element is a rotating string.