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US 2008/0155837 A1Published application
Head for a rotary line trimmer apparatus
OwnerMark R. Mooreinventor
Life of this patent
Estimating the term…
Abstract
An improved head for a flexible line trimmer apparatus is provided. The improved head includes a metal tubing that extends through the head and surrounds a cutting line of selected length. The tubing is provided with a flared exit portal increasing the efficiency of the head. The contact surface eliminates the possibility of the cutting line fusing to plastic surfaces due to heating caused by friction. The head is surrounded with an interior perimeter counterweight to store kinetic energy on each end having a parabolic surface of revolution concentric with the axis of the tubing. A replaceable cartridge is provided to increase the ease of maintenance and the useful life of the head.
Claims27
A line trimming head comprising:
- (a) a housing;
- (b) a central support fixed within the housing;
- (c) an arcuate metallic tube diametrically fixed within the housing and forming a continuous axially circumferential passage for a trimming line;
- (d) the arcuate metallic tube avoiding the central support and forming at least one blade slot;
- (e) the arcuate metallic tube further having a first exit port and a second exit port;
- (f) the first exit port forming a first convex surface of revolution about a central axis of the arcuate metallic tube;
- (g) the second exit port forming a second convex surface of revolution about the central axis of the arcuate metallic tube;
- (h) a gripper movable between a first position and a second position;
- (i) the first position allowing the admittance of the trimming line through the arcuate metallic tube;
- (j) the second position providing for holding the trimming line in the arcuate metallic tube;
- (k) the gripper having at least one locking blade extending into the at least one blade slot, the locking blade having a clamp hole adjacent the axially circumferential passage;
- and,
- (l) the locking blade cooperating with the arcuate metallic tube to hold the trimming line when the gripper is in the second position.
10 more elements
A line trimming head for a line trimmer comprising:
- (a) a support shell having an equatorial perimeter;
- (b) a central attachment stanchion within the support shell for connection to a line trimmer;
- (c) a round circumferentially continuous tubular passage fixed within the support shell adapted to slidably contact a trimming line segment;
- (d) the round circumferentially continuous tubular passage having a first generally convex opening at a first perimeter location on the support shell and a second generally convex opening at a second perimeter location on the support shell;
- (e) a first arcuate counterweight having two arcuate projections spanning generally a first half of the equatorial perimeter of the support shell and one eyelet surrounding the first generally convex opening;
- (f) a second arcuate counterweight having two arcuate projections spanning generally a second half of the equatorial perimeter of the support shell and one eyelet surrounding the second generally convex opening;
- (g) a first locking blade and a second locking blade radially disposed generally perpendicular to the round circumferentially continuous tubular passage and having a pair of clamp slots open to the round circumferentially continuous tubular passage;
- (h) the first locking blade and second locking blade slidable between a first position in which the trimming line segment may slide in the round circumferentially continuous tubular passage and a second position in which the trimming line segment may not slide in the round circumferentially continuous tubular passage;
- and,
- (i) a spring to bias the first locking blade and the second locking blade in the second position.
7 more elements
A line trimming head for a line trimmer comprising:
- (a) a housing;
- (b) a trimmer shaft hub support centrally located in the housing;
- (c) a pair of cartridge retaining walls fixed within the housing forming a positioning channel adjacent the trimmer shaft hub support;
- (d) a replaceable wear cartridge removably fitted within the positioning channel;
- (e) the replaceable wear cartridge further comprising:
- (f) a first angled section, a guide section and a second angled section all integrally formed;
- (g) a circumferentially continuous hole longitudinally spanning the first angled section, the guide section and the second angled section;
- (h) a first concave portal formed in a face of the first angled section contiguous with the circumferentially continuous hole;
- (i) a second concave portal formed in a face of the second angled section contiguous with the circumferentially continuous hole;
- (j) a first blade slot in the replaceable wear cartridge perpendicular to and in ducted communication with the circumferentially continuous hole;
- (k) a second blade slot in the replaceable wear cartridge perpendicular to and in ducted communication with the circumferentially continuous hole;
- (l) a first locking blade having a first locking hole slidably disposed in the first blade slot so that the first locking hole intercedes into the circumferentially continuous hole;
- (m) a second locking blade having a second locking hole slidably disposed in the second blade slot so that the second locking hole intercedes into the circumferentially continuous hole;
- (n) a rigid connection between the first locking blade and the second locking blade;
- (o) a biasing means between the rigid connection and the replaceable wear cartridge to bias the first locking blade and the second locking blade between a first position to allow passage of a trimming line through the first locking hole, the second locking hole and the circumferentially continuous hole;
- and,
- (p) a second position to prevent passage of the trimming line through the first locking hole, the second locking hole and the circumferentially continuous hole.
14 more elements
A line trimming head for a line trimmer;
- comprising:
- (a) a cover means having a generally circular perimeter, a perimeter plane and a set of opposing pole locations for housing and positioning a set of working components of the line trimming head;
- (b) an axial support means, between the opposing set of pole locations, for attachment of the line trimming head to the line trimmer;
- (c) a metallic channel means, operatively positioned in the plane of the perimeter of the cover means, for providing a circumferentially continuous channel for a segment of cutting line;
- (d) the metallic channel means further comprising a set of diametrically opposed curved portals for guiding the segment of cutting line;
- (e) a gripper blade means, passing through the metallic channel means, for gripping the segment of cutting line;
- (f) the gripper blade means, further being slidably movable within the plane of the perimeter between a first position in which the segment of cutting line can slide through the circumferentially continuous channel and a second position in which the segment of cutting line cannot slide through the circumferentially continuous channel;
- (g) a bias means, adjacent the gripper blade means and the metallic channel means for biasing the gripper blade means in the second position;
- (h) a matched set of two semicircular counterweights positioned at diametric locations in the plane of the perimeter;
- and
- (i) each of the semicircular counterweights having at least two arcuate projection means for dissipation of heat from movement of the segment of cutting line during operation of the line trimmer.
8 more elements
Dependencies are inferred from the claim text.