PNEUMATIC SOURCE OF SEISMIC SIGNALS Russian patent published in 1994 - IPC

FIELD: seismic prospecting. SUBSTANCE: source has case 1 provided with ports 2 overlapped with movable cylinder 4 having flange 5. Electropneumatic valve 6 is secured to face of case 1 wherein pipe 3 provided with sleeve 7 is received. When the source is filled compressed air enters main passage 12 through supplying passage 9, space 18 of the electropneumatic valve and by-pass passage 10. Sleeve 7 is pressed to seal 23 to cut-off starting space 21 from starting passages 17. Air enters working space 19 through connecting passage 14 and additional passage 15 and then enters starting space 21 through passage 16 for compensating pressure. Air enters control space 20 through side passage 13 for closing ports 2 by using cylinder 4. When valve 6 cames into action air is discharged from space 18 through passages 11 and pressure above bottom 8 of sleeve 7 and in main passage 12 decreases. Sleeve 7 is shifted to the top and starting space 21 is coupled with accelerating space 22 through starting passages 17. Pressure acts on flange 5 from bellow, moves cylinder 4 upward and the ports are opened. Returning of cylinder 4 is damped by accelerating space 22. Pipe 3 is free from axial loadings. EFFECT: enhanced reliability. 1 dwg