Filament-type trimmer
OwnerJohn D. Sheldon, Textron Inc.inventors
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Abstract
A filament-type trimmer comprises at least one filament spool carried by a rotary housing driven by a motor the speed of which increases with decrease in load. Means for normally restraining rotation of the filament spool relative to the casing is responsive to centrifugal force to release the spool to feed additional filament when the speed of the motor increases due to a decrease in load by reason of the extending end of the filament having become shorter by wearing or breaking off. In one embodiment the feed of additional filament is delayed until by manual control the speed is reduced below normal operating speed.
Claims8
A filament-type trimmer comprising a rotatable housing, at least one spool rotatably supported by said housing, at least one filament wound on said spool, guide means on said housing past which an end portion of said filament extends in passing from said spool to the exterior of said housing whereby said end portion of said filament is extended from said housing by centrifugal force to act as rotary cutting means upon rotation of said housing at sufficient speed, means for rotationally driving said housing, said driving means having such speed-load characteristics that the speed of rotation increases with a decrease in load, means for normally restraining rotation of said spool relative to said housing and responsive to centrifugal force upon increase in the speed of rotation of said housing upon decrease in load on said driving means upon decrease in length of the extended end portion of said filament to release said spool for rotation relative to said housing by the pull exerted by centrifugal force on said extended end portion of said filament to thereby increase the length of said extended end portion of said filament.
Dependencies are inferred from the claim text.