Fixed line head for flexible line rotary trimmers

A cutting head for rotary trimmers in which at least one, and preferably two relatively short fixed lengths of flexible cutting line are inserted into opposed channels in the head and are secured in place by a pair of spring biased toothed cams. Each of the cams is pivotally mounted on a post within the housing adjacent one of the channels and defines a curvilinear camming surface having a plurality of uniformly spaced teeth thereon that project into the channels at increasing angles of inclination from the outermost tooth to the innermost tooth for engaging the line. A pair of torsion springs bias the cams to pivot on their mounting teeth such that the backsides of the teeth are continually urged toward the openings to the channels thereby allowing line to be inserted inwardly into the head past the toothed cams but retained by the cams against any outwardly directed forces acting on the line. The cams are symmetrically balanced about their axes of rotation so as to be unaffected by centrifugal force acting thereon during use.