Patent ID: 6371567
Filing Date: 2002-04-16
Classification: B28D,E21C

Abstract:
A bit holder for use in road milling, trenching and mining equipment as part of an assembly including a bit, said bit holder and a bit block, said bit being mountable in a first bore through said bit holder and said bit holder being mountable in a second bore through said bit block, said bit holder comprising:a bit receiving front portion terminating at an annular flange for engaging a face of said bit block, a shank portion extending axially rearwardly from said annular flange, said shank portion including a declining taper from adjacent said annular flange to adjacent a distal end thereof, said declining taper providing an interference fit between said bit holder and said bit block, said shank portion including an axial bore centrally therethrough, and means on said shank portion for providing increased resilience for an outer surface of said declining taper to increase the usable interference fit between said declining taper and said second bore on said bit block by at least about four times a standard interference fit therebetween as said shank portion is fully mounted on said second bore.