ROLLER BIT Russian patent published in 1994 - IPC

FIELD: drilling. SUBSTANCE: check valve is made in form of disk 7 whose side surface is congruent to inner surface of sleeve 4 in its inclined cross-section. Disk 7 is secured for turning and closing the sectional area of sleeve 4. Disk 7 is installed with inclination below side ports 6 by means of bearing axle 8. The latter is secured in sleeve 4 on the side of lower end of disk 7. Lower part of disk 7 is spring-loaded on the side of lower end of disk 7 relative to sleeve 4. Support 9 of spring is radially displaced from axle 8 to side of lower part of disk 7. Disk 7 may be made in form of ellipse. In operation, reliability of check valve increases. EFFECT: higher efficiency. 2 cl, 1 dwg