Rotary drill bit

Claim 1

A rotary drill bit, particularly for deep-well drilling, comprising a body having a gauge region, a cutting surface which is defined by projecting cutting members having a face and a cutting edge supported at the outer periphery of the body between a central region at the bottom of the bit and a lateral region between the central region and the gauge region on supporting members and nozzle passages through which flushing liquid can flow over and around said bit upwardly to the top of the drill hole and which nozzle passages have outlets spaced about the cutting surface, said outlets being formed so as to direct fluid towards the faces of the cutting members and which gives the jets of flushing liquid emerging therefrom an alignment having at least one flow component facing in the direction of the flushing liquid flowing upwardly around the outer periphery of said body, and in which said one flow component of the jets of flushing liquid emerging from the nozzles increases in magnitude from nozzles disposed in the central region of said body towards nozzles provided in the lateral regions of the body.