发明名称 |
Safety elevator |
摘要 |
An elevator for supporting a string of pipe in a well rig is actuable between a closed condition for gripping of the pipe and an open condition, and includes a safety device for preventing opening of the elevator when a string of pipe is positioned in and supported by the elevator, to thus prevent accidental dropping of the string into a well. The elevator may be opened and closed by air pressure, with the safety device preferably including a sensing element positioned to respond to the presence of a well pipe in the elevator at a location to be supported thereby, and a valve actuable by the sensing element to control the delivery of pressure fluid to the elevator.
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申请公布号 |
US5340182(A) |
申请公布日期 |
1994.08.23 |
申请号 |
US19920941233 |
申请日期 |
1992.09.04 |
申请人 |
VARCO INTERNATIONAL, INC. |
发明人 |
BUSINK, CORNELIS L.;VAN RIJZINGEN, JOHANNES W. H.;MASON, DAVID B. |
分类号 |
E21B19/06;E21B19/07;(IPC1-7):E21B19/06 |
主分类号 |
E21B19/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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