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NTIS 바로가기국가/구분 | United States(US) Patent 등록 |
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국제특허분류(IPC7판) |
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출원번호 | US-0191407 (1988-05-09) |
우선권정보 | DE-3715512 (1987-09-09) |
발명자 / 주소 |
|
출원인 / 주소 |
|
인용정보 | 피인용 횟수 : 9 인용 특허 : 2 |
An apparatus for producing pressure pulses in an oil well fluid medium is established which includes a main valve member moveable relative to a supporting member by a pressure gradient between two flow channels. The main valve body is longitudinally moveable relative to the supporting body, and a ga
An apparatus for producing pressure pulses and in oil well fluid medium flowing in a drill string, comprising: a valve assembly coupled in said drill string, said valve assembly comprising, an exterior member, an axially movable generally tubular valve member located generally coaxially within said
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