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US 10,945,365 B2Granted
Mower cord and manufacturing method for mower cord
AssigneeSanyo Tegusu Co., Ltd.
InventorsToshio Ishikawa, Shigeki Ichikawa, Masaya Suzuki
Life of this patent
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Abstract
The present invention relates to a manufacturing method for a mower cord and includes pressing a resin wire rod and plastically deforming at least part of the wire rod in an axis perpendicular direction. Work-hardening of a surface of the plastically deformed portion allows dramatic enhancement of mowing efficiency.
Claims17
A manufacturing method for a mower cord, comprising:
- extruding a resin raw material and molding the resin raw material into a resin rod having a longitudinal axis;
- after the molding is complete, pressing the molded resin rod between a pair of opposed pressing surfaces of a pressure die which approach the molded resin rod in a direction perpendicular to the longitudinal axis and plastically deforming by cold working at room temperature at least part of the molded resin rod in a direction perpendicular to the longitudinal axis;
- wherein:
- the pressure die includes a pair of opposed side walls oriented transversely to the pressing surfaces and each having an uneven shape;
- the pressing surfaces having outer edges shaped to conform with the uneven shapes of the side walls;
- a site where the at least part of the molded resin rod is cold-worked has a flat portion which is thinner than the molded resin rod before the pressing;
- the flat portion protrudes outwardly in a radial direction of the molded resin rod;
- a plurality of uneven portions which are continuous in a longitudinal direction of the molded resin rod are formed at the flat portion by the side walls such that outer distal edges of the uneven portions conform to the uneven shapes of the side walls;
- the flat portion and the uneven portions are formed simultaneously by the cold working;
- and
- the pressing is carried out by moving the opposed pressing surfaces relative to the side walls in a pressing direction perpendicular to the longitudinal axis of the molded resin rod.
8 more elements
A method of manufacturing a mower cord, said method comprising the steps of:
- forming a solid resin rod from a resin raw material, the solid resin rod having a longitudinal axis;
- thereafter pressing the solid resin rod between a pair of opposed pressing surfaces of a pressure die which are movable in a pressing direction perpendicular to the longitudinal axis and plastically deforming by cold working at room temperature part of the solid resin rod in a direction perpendicular to the longitudinal axis to form a flat portion that is thinner than the solid resin rod before the step of pressing and cold working, the flat portion protruding outwardly in a radial direction of the solid resin rod;
- wherein the step of pressing and cold working, simultaneously with forming the flat portion, forms a plurality of uneven portions along the flat portion with opposed and uneven side walls of the pressure die such that the plurality of uneven portions extend continuously in the longitudinal direction of the solid resin rod and such that outermost edges of the uneven portions conform to the opposed and uneven side walls, wherein outer edges of the pressing surfaces disposed immediately adjacent the respective side walls have shapes which respectively conform thereto;
- and
- wherein the step of pressing and cold working includes moving the opposed pressing surfaces towards the solid resin rod and along and relative to the side walls.
2 more elements
Dependencies are inferred from the claim text.