Cutting head for a rotary trimmer
AssigneeKwik Products, Inc.
InventorFernando R. Iacona
Life of this patent
Estimating the term…
Abstract
A cutting head for a rotary trimmer has a rotating body from which several flexible cord-like filament cutting blades or flails extend radially so that additional flail length can be fed from the device by merely bumping the rotating body on the ground. The improvement includes a plurality of truncated, bell-shaped configured tangs which extend into a serpentinous cam slot. Bumping of the device on the ground causes the tangs to move from stable positions to other stable positions allowing relative movement between the outer case of the trimmer and a spool of flail therein so that a predetermined length of flail is fed out through the case.
Claims6
A cutting head for a rotary trimmer having two diametrically opposed cutting flails which extend outwardly from a spinning assembly including two major assemblies, a cap assembly and a spool assembly having an axis of rotation, a bumper for engagement with the ground and means to allow predetermined lengths of flail to feed outwardly in response to the striking of the bumper on the ground, the improvement comprising:
- a cam member having a cam slot therein connected to one of said assemblies, said cam slot being a serpentinous cam slot having one portion formed by the radial surface of a washer, said cam slot being defined by radially extending tangs which are radially spaced, with alternate tangs being spaced along said axis of rotation so as to define said serpentinous cam slot, each said tang being of truncated, bell-shaped configuration so as to avoid stress concentrations;
- a follower member connected to the other of said assemblies and having diametrically opposed cam followers thereon positioned to ride in said cam slot, said follower member further including six outwardly extending knobs, said spool assembly surrounding said follower member and having six grooves extending parallel to said axis of said spool assembly, said grooves having parallel sidewalls, with two diametrically opposed grooves having lateral cutouts at the lower ends thereof for receiving two of said knobs, said two of said knobs being positioned in said lateral cutouts to releasably retain said follower member to said bumper;
- said cam follower of the follower member being defined by four radially spaced tangs extending radially inwardly of said follower member, each said tang being of truncated, bell-shaped configuration for minimizing stress concentrations when said cam follower is engaged in said cam slot;
- and
- biasing means acting between said cam member and said follower member tending to urge said cam follower into stable positions on said cam slot when undisturbed by force applied to said bumper and adapted to be overcome by suitable force applied to said bumper, said cam slot being generally parallel to the force applied by said biasing means.
Dependencies are inferred from the claim text.