PITTINGER, SR., CHARLES B.;PITTINGER, JR., CHARLES B.
发明人:
PITTINGER, SR., CHARLES B.,PITTINGER, JR., CHARLES B.
申请号：
US19770771426
公开号：
US4118864(A)
申请日:
1977.02.24
申请国别(地区):
美国
年份:
1978
代理人:
摘要：
A filament incremental feed for vegetation filament trimmers of the hollow shaft or similar type in which a free-end of filament is swung as a cutting length from the lower end of the hollow shaft and replaced as worn by pulse feed; the feed includes in a preferred embodiment a vertical spindle mounting a worm pinion coaxially on the hollow-shaft at the top of the hollow shaft. The worm pinion is free to rise and to rotate relative to the spindle when retarded in rotation by friction, as by a friction bar engaging an upward extension of the gear pinion which has a friction surface. Plural spools, in the preferred embodiment, rotationally mounted on substantially horizontal axes on a yoke on the hollow shaft engage the worm pinion with gear teeth around the flanges of the spools. The lead angle of the worm pinion provides a mechanical advantage preventing rotation of the worm gear by the spool geared flanges.
