发明名称 Locating devices for soil displacement hammers
摘要 A locating device for a soil displacement hammer is disclosed and comprises a cylindrical, radio wave-transparent housing which is releasably connected between an air line for the soil displacement hammer (mole) and the hammer itself so as to permit air communication through the housing. Mounted along the axis of the housing is a cylindrical radio wave transmitter, such that, when the hammer is driven through the ground by repeated pneumatic impact, its location under the ground can be detected at the surface.
申请公布号 US4854398(A) 申请公布日期 1989.08.08
申请号 US19880176935 申请日期 1988.04.04
申请人 HOLLOWAY, DAVID E. 发明人 HOLLOWAY, DAVID E.
分类号 E21B7/04;E21B7/26;E21B47/022;E21B47/12;(IPC1-7):E21B47/024 主分类号 E21B7/04
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