ROLLER BIT (VERSIONS) Russian patent published in 2015 - IPC E21B10/18 

FIELD: process engineering.

SUBSTANCE: invention relates to rock crushers, primarily, drill bits intended for drilling with the use of central flushing assembly. Drill bit comprises body with central stepped channel, cutters secured at bit legs and pipe made of resilient material arranged in said central channel. In compliance with first version, resilient pipe in cross-wise direction is composed of two circular sectors. One of them is reinforced with lengthwise expansion springs. Top end of the latter is connected with the body while bottom end is coupled with pipe outlet end. In compliance with second version, resilient pipe in cross-section is composed of two circular sectors reinforce by lengthwise expansion springs. Top end of the latter is connected with the body while bottom end is coupled with pipe outlet end. Note here that expansion factor of the springs of one sector differs from that of springs of the other sector.

EFFECT: higher efficiency of drilling.

2 cl, 3 dwg