IMPROVEMENTS IN DRILL BITS FOR DEEP DRILLING, TRIAL DRILLING, PROSPECTING DRILLING AND LIKE DRILLING OPERATIONS

摘要

1,210,012. Drill bits. ZENTRALES REPARATUR-UND AUSRUSTUNGSWERK VEB. 28 Feb., 1968 [28 Feb., 1968], No. 9698/ 68. Heading E1F. [Also in Division B3] A drill bit comprises a plurality - for example 3 or 5- of cutting elements 3 sintered onto the rim of a steel body 1, with rinsing channels 9 being provided between the elements and having constricted inlets 11 to produce turbulence.