| 摘要 |
A lock member (10) is disclosed for securing to a lock structure (14) in a conduit. The lock member (10) comprises a housing (24), a shoulder (16) on the lock structure (10), a locking device (26) movably mounted on the housing (24) for movement between a first retracted position and a second extended position in which the locking device (26) enters a corresponding locking recess (30) in the lock structure (14). The shoulder (16) of the lock member (10) is movably mounted on the housing (24) between a first position in which, in use, the shoulder (16) bears upon the shoulder (18) of the locking structure (14) and the locking device (26) when in the extended position is disengaged from the surfaces of the locking recess (30) of the lock structure (14). When the shoulder (16) of the lock member (10) is in the second axial position, the locking device (26) bears upon a surface of the locking recess (30) so as to bear at least a portion of any load applied to an end of the lock member (10). The lock member (10) also includes a selective locking device (32) for selectively locking the shoulder (16) in the first position. The lock member is particularly advantageous when used in an oil or gas well and especially tubing in oil or gas wells. In this case, the lock member is in the form of a lock mandrel and the lock structure is in the form of a landing nipple.
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