MILLING CUTTER FOR DRILL STRINGS DRILLING

摘要

Milling cutter for drill string drilling at emergency operations in wells has pre-fabricated body in which spring is placed, movable blades with cutters. The blades are rigidly connected to block with tail element at the end of which support is mounted (in process of instrument assembling). Body of the drill has cavity with collars distance between which is equal to sum of lengths of compressed spring and support holding block of blades. In the lower part of the body guides of forward pair "body-blade block" are provided. The guides of forward pair "body-blade block" are arranged as central opening for tail element and slots for blades dimensions of elements of which are calculated in such way that after assemblage blade outreach correspond to length of cutters, though blades in operating condition are completely hidden in body.