Grooved nut and manufacturing method thereof
AssigneeKabushiki Kaisha Sakamura Kikai Seisakusho
InventorsYoshikazu Sakamura, Fumio Kamiyama
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Abstract
A grooved nut including a cylindrical shaft portion having a screw hole at the center, a head portion whose outer periphery is polygonal and which is provided at one end portion of the shaft portion, and a peripheral groove provided at a boundary part between the head portion and the shaft portion, in which the peripheral groove is formed by a plasticizing process.
Claims3
A method of manufacturing a grooved nut which has a cylindrical shaft portion having a screw hole at its center, a head portion whose outer periphery is polygonal and which is provided at one end portion of the shaft portion, and a peripheral groove provided at a boundary part between the head portion and the shaft portion, comprising the steps of:
- decreasing the diameter of one end portion of the cylindrical material having a lower hole of the screw hole provided at the center by a pressing process to make the major diameter smaller than diameters of the other portions, and
- increasing the distal end of the smaller diameter portion by a pressing process while constraining the proximal end of the smaller diameter portion by using a split mold, thereby forming the head portion at the tip and the peripheral groove continuous to the head portion.
Dependencies are inferred from the claim text.