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US 2003/0070296 A1Published application
Method for manufacturing spool valve
AssigneeAoyama Seisakusho Co., Ltd.
InventorsKeigo Kato, Masataka Mizuno
Life of this patent
Estimating the term…
Abstract
A spool valve is provided which has a plurality of small-diameter portions formed at predetermined spacings on a peripheral surface of a shaft, and pairs of annular ridges on peripheral surfaces of the small-diameter portions to have a larger diameter than an inner diameter of collars. The collars are closely fitted between the annular ridges to make valve bodies, and the collars include an inner wall, an outer wall and at least one connection therebetween, and an annular gap is provided between the inner wall and the outer wall.
Claims9
A method for manufacturing a spool valve, comprising:
- fitting a plurality of collars onto a shaft material and aligning the plurality of collars in predetermined positions, said collars being formed from a metallic sheet and comprising an inner wall, an outer wall and an annular gap therebetween;
- and
- using a rolling die to reduce in diameter the shaft material around both ends of each of the collars to cause plastic flow of material to form annular ridges at both ends of each of the collars which have a larger diameter than an inner diameter of the collars to thereby fix the collars to the shaft.
Dependencies are inferred from the claim text.