Aerodynamic Trimmer Head For Use In Flexible Line Rotary Trimmers

Abstract

An aerodynamic trimmer head for use in flexible line rotary trimmers having a plurality of aerodynamic elements defined by the upper and lower head surfaces that during rotation of the head, draw air downwardly about the trimmer drive mechanism onto the upper head surface and move the air outwardly from the head into the plane of the extended cutting line and at forward inclination in the direction of rotation. The downwardly moving air cools the trimmer drive mechanism and the outwardly and forwardly moving air reduces the drag on the head and the extended cutting line. The aerodynamic elements preferably include a plurality of troughs extending downwardly and forwardly along the upper head surface, a perimeter surface for deflecting air moved by the troughs into a generally horizontally extended zone of moving air about the extended cutting line and a plurality of dimples formed in a lower surface of the head.

1 - 61 . (canceled) 
     
     
         62 . An aerodynamic trimmer head for use in flexible line rotary trimmers, said head comprising:
 a housing adapted to be operatively connected to a rotary trimmer to effect rotation of the head, said housing defining at least one opening therein for the passage of line therethrough such that a length of line can project from said housing during rotation of the head for the cutting of vegetation and including an upper housing portion, said upper housing portion defining an upper head surface; and   a plurality of aerodynamic elements defined by at least said upper head surface, at least a portion of said elements being configured so as to direct air outwardly from said head during rotation thereof at a forward inclination in the direction of rotation and about the portion of the line projecting therefrom, thereby decreasing the drag on said line.   
     
     
         63 . The aerodynamic trimmer head of  claim 62  wherein said housing includes a lower housing portion, said lower housing portion defining a lower head surface and wherein said aerodynamic elements include a plurality of dimples on said lower head surface. 
     
     
         64 . The aerodynamic trimmer head of  claim 62  wherein said aerodynamic elements include at least one housing surface extending about a perimeter portion of said head exteriorly of and adjacent to and below said at least one opening in said housing, said housing surface cooperating with said aerodynamic elements defined by said upper head surface during rotation of said head to direct air outwardly from said head at said forward inclination in a substantially planar disposition about the length of the portion of the line projecting from said head. 
     
     
         65 . The aerodynamic trimmer head of  claim 62  wherein said forward inclination is with respect to said head during rotation of said head. 
     
     
         66 . The aerodynamic trimmer head of  claim 64  wherein said housing includes a lower housing portion and said at least one housing surface comprises an upper annular end portion of said lower housing portion. 
     
     
         67 . The aerodynamic trimmer head of  claim 64  wherein said housing includes a lower housing portion, said lower housing portion defining a lower head surface and wherein said aerodynamic elements include a plurality of dimples on said lower head surface. 
     
     
         68 . The aerodynamic trimmer head of  claim 64  wherein said forward inclination is with respect to said head during rotation of said head. 
     
     
         69 . An aerodynamic trimmer head for use in flexible line rotary trimmers, said head comprising:
 a housing adapted to be operatively connected to a rotary trimmer to effect rotation of the head, said housing defining at least one opening therein for the passage of line therethrough such that a length of line can project from said housing during rotation of the head for the cutting of vegetation and including an upper housing portion, said upper housing portion defining an upper head surface having an inner upper portion and an outer lower portion; and   a plurality of aerodynamic elements defined by at least said upper head surface, said elements extending downwardly and forwardly in the direction of rotation from said inner upper portion of said upper head surface to said lower outer portion thereof and being configured so as to direct air outwardly from said head during rotation thereof at a forward inclination in the direction of rotation and about the portion of the line projecting therefrom, thereby decreasing the drag on said line.   
     
     
         70 . The aerodynamic trimmer head of  claim 69  wherein said housing includes a lower housing portion, said lower housing portion defining a lower head surface and wherein said aerodynamic elements include a plurality of dimples on said lower head surface. 
     
     
         71 . The aerodynamic trimmer head of  claim 69  wherein said aerodynamic elements include at least one housing surface extending about a perimeter portion of said head exteriorly of and adjacent to and below said at least one opening in said housing, said housing surface cooperating with said aerodynamic elements defined by said upper head surface during rotation of said head to direct air outwardly from said head at said forward inclination in a substantially planar disposition about the length of the portion of the line projecting from said head. 
     
     
         72 . The aerodynamic trimmer head of  claim 69  wherein said forward inclination is with respect to said head during rotation of said head. 
     
     
         73 . The aerodynamic trimmer head of  claim 71  wherein said housing includes a lower housing portion and said at least one housing surface comprises an upper annular end portion of said lower housing portion. 
     
     
         74 . The aerodynamic trimmer head of  claim 71  wherein said housing includes a lower housing portion, said lower housing portion defining a lower head surface and wherein said aerodynamic elements include a plurality of dimples on said lower head surface. 
     
     
         75 . An aerodynamic trimmer head for use in flexible line rotary trimmers, said head being adapted to be operatively connected to a rotary trimmer to effect rotation of the head and comprising:
 at least one opening therein for the passage of line therethrough such that a length of line can project from said head during rotation of the head for the cutting of vegetation;   an upper head surface; and   a plurality of aerodynamic elements defined by at least said upper head surface, at least a portion of said elements being configured so as to direct air outwardly from said head during rotation thereof at a forward inclination in the direction of rotation and about the portion of the line projecting therefrom, thereby decreasing the drag on said line.   
     
     
         76 . The aerodynamic trimmer head of  claim 75  wherein said aerodynamic elements comprise either a plurality of troughs extending outwardly and forwardly in the direction of rotation from an inner portion of said upper head surface to an outer portion thereof or a plurality of protrusions extending outwardly and forwardly in the direction of rotation from an inner portion of said upper head surface to an outer portion thereof. 
     
     
         77 . The aerodynamic trimmer head of  claim 75  wherein said troughs or protrusions extend outwardly and forwardly along non-linear paths. 
     
     
         78 . The aerodynamic trimmer head of  claim 75  wherein said aerodynamic elements include at least one curvilinear surface extending about a perimeter portion of said head exteriorly of and adjacent to and below said at least one opening in said head, said annular surface cooperating with said aerodynamic elements defined by said upper head surface during rotation of said head to direct air outwardly from said head at said forward inclination in a substantially planar disposition about the length of the portion of the line projecting from said head. 
     
     
         79 . The aerodynamic trimmer head of  claim 75  wherein said forward inclination is with respect to said head during rotation of said head. 
     
     
         80 . The aerodynamic trimmer head of  claim 76  wherein said aerodynamic elements include at least one curvilinear surface extending about a perimeter portion of said head exteriorly of and adjacent to and below said at least one opening in said head, said annular surface cooperating with said aerodynamic elements defined by said upper head surface during rotation of said head to direct air outwardly from said head at said forward inclination in a substantially planar disposition about the length of the portion of the line projecting from said head. 
     
     
         81 . The aerodynamic trimmer head of  claim 76  wherein said forward inclination is with respect to said head during rotation of said head. 
     
     
         82 . An aerodynamic trimmer head assembly for use in flexible line rotary trimmers, said assembly comprising:
 a trimmer head adapted to be operatively connected to a rotary trimmer to effect rotation of said head; said head defining an upper head surface;   at least one length of line carried by said head such that a portion thereof projects from said head during rotation of the head for the cutting of vegetation; and   a plurality of aerodynamic elements defined by at least said upper head surface, at least a portion of said elements being configured so as to direct air outwardly from said head during rotation thereof at a forward inclination in the direction of rotation and about the portion of the line projecting therefrom, thereby decreasing the drag on said line.   
     
     
         83 . The aerodynamic trimmer head of  claim 82  wherein said aerodynamic elements comprise either a plurality of troughs extending outwardly and forwardly in the direction of rotation from an inner portion of said upper head surface to an outer portion thereof or a plurality of protrusions extending outwardly and forwardly in the direction of rotation from an inner portion of said upper head surface to an outer portion thereof. 
     
     
         84 . The aerodynamic trimmer head of  claim 82  wherein said troughs or protrusions extend outwardly and forwardly along non-linear paths. 
     
     
         85 . The aerodynamic trimmer head of  claim 82  wherein said forward inclination is with respect to said head during rotation of said head. 
     
     
         86 . The aerodynamic trimmer head of  claim 82  wherein said aerodynamic elements include at least one curvilinear surface extending about a perimeter portion of said head adjacent to and below a portion of the line projecting from said head, said annular surface cooperating with said aerodynamic elements defined by said upper head surface during rotation of said head to direct air outwardly from said head at said forward inclination in a substantially planar disposition about the length of the portion of the line projecting from said head. 
     
     
         87 . The aerodynamic trimmer head of  claim 86  wherein said forward inclination is with respect to said head during rotation of said head. 
     
     
         88 . The aerodynamic trimmer head of  claim 83  wherein said aerodynamic elements include at least one curvilinear surface extending about a perimeter portion of said head adjacent to and below a portion of the line projecting from said head, said annular surface cooperating with said aerodynamic elements defined by said upper head surface during rotation of said head to direct air outwardly from said head at said forward inclination in a substantially planar disposition about the length of the portion of the line projecting from said head.