发明名称 PERFEZIONAMENTI A O RIGUARDANTI UTENSILI PER SCAVI DI INBOCCO
摘要 <p>A time delay mechanism wherein there is provided a time delay between the application of a pressure to the mechanism and an action being carried out as a result of the application of said pressure. The mechanism may comprise a first piston and piston chamber and a second piston and piston chamber. Communication of a viscous fluid between said piston chambers may be achieved by means of at least one contoured flow passage.</p>
申请公布号 IT1274529(B) 申请公布日期 1997.07.17
申请号 IT1995MI01017 申请日期 1995.05.19
申请人 PETROLEUM ENGINEERING SERVICES LIMITED 发明人 MAITLAND GEORGE
分类号 E21B34/10;(IPC1-7):E21B 主分类号 E21B34/10
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