Title:
【発明の名称】係止システム
Document Type and Number:
Japanese Patent JP2001507414
Kind Code:
A
Abstract:
PCT No. PCT/AU96/00537 Sec. 371 Date Feb. 27, 1998 Sec. 102(e) Date Feb. 27, 1998 PCT Filed Aug. 27, 1996 PCT Pub. No. WO97/08426 PCT Pub. Date Mar. 6, 1997Locking system (196) is provided for selectively locking an external sleeve (76) to a main body (74) of a downhole tool (14). Locking system (196) comprises a pair of opposed holes (198) formed in the main body (74). The holes (198) capture respective locking balls (200). A channel (210) extends from each hole (198) longitudinally about the outer surface of the main body (74). A spring (206) held within the main body (74) acts to push the balls (200) out of holes (198). Openings (212) are also formed in the sleeve (76) and disposed so that the balls (200) can protrude therethrough and contact the inner circumferential surface (28) of a drive sub (12) by virtue of the bias of spring (206). When the internal diameter of the drive sub (12) is relatively small, the balls (200) are pushed inwardly against the spring (206) and reside, at least partially, within holes (198). This prevents the balls from moving longitudinally about channels (210) thereby locking the sleeve (76) to the main body (74). However, when the internal diameter of the drive sub increases, the balls (200) are pushed radially outwardly by the spring (206) to the extent that they can then escape holes (198) and roll along channels (210). This allows the sleeve (76) to slide relative to the body (74).
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Inventors:
Gevin Thomas Macleod
Application Number:
JP50962797A
Publication Date:
June 05, 2001
Filing Date:
August 27, 1996
Export Citation:
Assignee:
D.H.T Technologies Technologies L.T.D.
International Classes:
E21B23/03; E21B10/64; E21B23/02; (IPC1-7): E21B23/03
Attorney, Agent or Firm:
Kashiwara Mieko