BORE-HOLE REAMER Russian patent published in 1998 - IPC

FIELD: bore-hole drilling machinery and equipment. SUBSTANCE: this reaming device is intended for increasing diameter of bore-holes in preset interval. Installed in hollow body of reamer are extendible roller-type drilling bits with shanks. Connected with body is cylinder with ring-type piston installed in it. Cylinder together with piston create hydraulic chamber. Installed in ring-type piston for possible interaction with shanks of roller-type drilling bits are detent and device for fixing roller-type drilling bits in idle position. Aforesaid device for fixing roller-type drilling bits is made in the form of radially spring-biased circular segments and additional ring-type piston. Installed between additional ring-type piston and circular segments is pusher which is intended for freeing segments from engagement with reamer cylinder. Additional ring-type piston can be made in the form of self-sealing collar. Aforesaid embodiment increases operating capacity of bore-hole reamer. EFFECT: higher efficiency. 2 cl, 6 dwg