Title:
DROP SHAFT
Document Type and Number:
Japanese Patent JP3420744
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To industrially produce a drop shaft as much as possible.
SOLUTION: It is possible to industrially produce the drop shaft 1 by saving manual operation as the drop shaft 1 is constituted by constituting a vertical pipe conduit of concentric inner and outer double pipes 3, 5, forming spiral grooves 7, 8 by blow-molding under a cold parison method on an inner surface of the outer pipe 3 and an outer surface of the inner pipe 5 and screwing and fitting an outer peripheral edge 6 and an inner peripheral edge of a spiral guide plate 4 in these spiral grooves 7, 8.
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Inventors:
Hatsuo Sakai
Hiroshi Nishibori
Hiroshi Nishibori
Application Number:
JP2000311072A
Publication Date:
June 30, 2003
Filing Date:
October 11, 2000
Export Citation:
Assignee:
Mapura Co., Ltd.
Mitsubishi Plastics Co., Ltd.
Mitsubishi Plastics Co., Ltd.
International Classes:
E03F3/04; E02D29/12; F16L11/12; F16L55/00; (IPC1-7): F16L55/00; E02D29/12; E03F3/04; F16L11/12
Domestic Patent References:
| JP11236984A | ||||
| JP2001279798A | ||||
| JP9269086A | ||||
| JP11293754A | ||||
| JP1073185A | ||||
| JP1122868A |
Attorney, Agent or Firm:
Yoshihiko Okabe
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