Large hole earth boring drill bit

Claim 1

AN EARTH BORING DRILL BIT COMPRISING A HEAD OF GENERALLY DISC SHAPE ABOUT A CENTRAL AXIS AND HAVING MEANS ON ONE FACE FOR SECURING A ROTARY DRIVING STEM TO THE HEAD CONCENTRICALLY WITH SAID AXIS, A SERIES OF PAIRS OF CUTTER SUPPORT ARMS EXTENDING FROM THE OPPOSITE FACE, THE PAIRS BEING SPACED FROM ONE ANOTHER ABOUT SAID AXIS AND CIRCUMFERENTIALLY ALIGNED IN GROUPS, THE GROUPS BEING AT DIFFERENT DISTANCES FROM SAID AXIS, THE ARMS OF EACH PAIR BEING AT DIFFERENT RADIAL DISTANCES FROM SAID AXIS AND HAVING OPPOSED, ALIGNED BEARING SUPPORT PARTS FOR RECEIVING AND SUPPORTING THE OPPOSITE ENDS OF A CUTTER BEARING, A CUTTER BEARING SHAFT HAVING SPACED PORTIONS INTERLOCKED WITH THE BEARING SUPPORT PARTS OF THE RESPECTIVE ARMS OF EACH PAIR, SAID INTERLOCKED BEARING SUPPORT PARTS AND SPACED SHAFT PORTIONS COMPRISING TIGHTLY INTERFITTING PROJECTIONS AND RECESSES ON SAID PARTS AND SHAFTS EXTENDING IN A DIRECTION TRANSVERSE TO AND SPACED FROM SAID SHAFT AXES TO BRACE THE ARMS OF EACH PAIR THROUGH SAID SHAFTSD AND PREVENT MOVEMENT OF SAID ARMS TO WARD AND FROM ONE ANOTHER, AND PROJECTIONS AND RECESSES ON SAID SHAFTS AND ONE ARM OF EACH PAIR HAVING RADIALLY EXTENDING INTERENGAGING SURFACES TO PREVENT ROTATION OF SAID SHAFTS RELATIVE TO SAID ARMS, AND A ROTATING TYPE CUTTER ROTATABLY MOUNTED ABOUT EACH SUCH SHAFT BETWEEN THE ARMS WITH WHICH THE SHAFT IS INTERLOCKED.