Patent ID: 8910388

Claim:
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 and a lower housing portion, said upper housing portion defining an upper head surface having an inner upper portion and an outer lower portion and said lower housing portion defining a lower head surface; and a plurality of aerodynamic elements defined by at least said upper head surface, 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 and wherein said aerodynamic elements comprise either a plurality of troughs 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 or a plurality of protrusions 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.