Title:
SET CONFIRMATION DEVICE OF WIRE LINE UNIT
Document Type and Number:
Japanese Patent JP3765093
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To simplify the structure of a wire line unit, by fitting loosely a piston provided in a core barrel head of a recessed part provided in a guide coupling and confirming the set condition.
SOLUTION: This set confirmation device is constituted of a piston 31d provided near the spear 31a of a core barrel head 31 and the second recessed part 11b provided at the connection part with a drill rod 50 of the inner wall of the base end of a guide coupling 11. When a core inner tube assembly 30 is not set at a specified position in an outer tube assembly 10, since the piston 31d is closely positioned to contact the inner wall of the rod 50, excavating water is kept at a specified pressure. When the tube assembly 30 is set at the specified position of the tube assembly 10, a latch 31b is fitted in the first recessed part 11a and the piston 31d is fitted loosely with a gap in the recessed part 11b and the excavating water flows from both gaps to the front end and the water pressure decreases. Hence, the set is detected because of decrease of the pump delivery pressure. In this way, the number of parts can be reduced without use of a check valve.
Inventors:
Tetsuya Endo
Takeshi Banri
Uto Gioki
Takeshi Banri
Uto Gioki
Application Number:
JP33888296A
Publication Date:
April 12, 2006
Filing Date:
December 04, 1996
Export Citation:
Assignee:
Mining Industry Co., Ltd.
International Classes:
E21B25/00; E02D1/04; (IPC1-7): E21B25/00; E02D1/04
Domestic Patent References:
| JP54017302A |
Attorney, Agent or Firm:
Eiichi Saito
Masami Hattori
Masami Hattori
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