Patent ID: 8939200
Filing Date: 2015-01-27
Classification: E21B

Abstract:
1. A tunable hydraulic stimulator comprising a hollow cylindrical housing having a longitudinal axis, a first end, and a second end, said first end being closed by a fluid interface for transmitting and receiving vibration, and said fluid interface comprising at least one accelerometer for producing an accelerometer signal representing vibration transmitted and received by said fluid interface; a driver element reversibly sealing said second end; and a hammer element longitudinally movable within said housing between said driver element and said fluid interface, said hammer element being responsive to said driver element for striking, and rebounding from, said fluid interface; wherein said driver element comprises an electromagnet/controller having cyclical magnetic polarity reversal characterized by a variable polarity reversal frequency; wherein longitudinal movement of said hammer element is responsive to said driver cyclical magnetic polarity reversal; and wherein longitudinal movement of said hammer element striking, and rebounding from, said fluid interface is substantially in phase with said polarity reversal frequency to generate vibration transmitted by said fluid interface.