Bit holder usable in bit blocks having either of a cylindrical or non-locking taper bore
View Patent ↗A bit holder for use in a bit assembly in road milling, mining and trenching equipment has a hollow generally cylindrical shank and first and second elongate slots positioned in spaced axial relation through the shank. The first slot extends along the shank to the distal end thereof. The second slot may be altered in length and/or shaped to fine tune the outward radial force the shank exerts against the bore of a bit holder block into which it is inserted.
1. A bit holder for use in road milling, trenching and mining equipment as part of an assembly including a bit, bit holder and bit holder block, with said bit holder block having a bit holder block bore that is one of: a) cylindrical, b) non-locking tapered and c) a combination of a non-locking tapered bore on a top portion of said bit block bore and a cylindrical bore on a bottom portion of said bit holder block bore,
said bit holder comprising,
a front body portion and a generally cylindrical hollow shank portion extending from a rear of said front body portion,
said generally cylindrical hollow shank portion defining a thick walled annular side wall and including a first elongate slot radially through said side wall extending generally axially along said side wall from a distal end thereof and having a termination on said thick annular side wall between said distal end of said shank to a forward end of said shank,
a second internal elongate slot substantially diametrically opposite said shank from said first elongate slot, said second slot extending generally axially along said thick annular side wall and varying in width along its length, with an upper termination spatially related to said rear of said front body portion, and a lower termination spatially related to said distal end of said shank,
at least portions of said shank having a free standing diametrical dimension, larger than a corresponding diametrical dimension of said bit holder block bore, and the insertion of said bit holder shank in said bit holder block bore providing sufficient outward radial force by radial deflection of said portions of said shank to retain said shank in both said bit holder block cylindrical and non-locking tapered bores during use.
2. A bit holder for use in road milling, trenching and mining equipment as part of an assembly including a bit, bit holder and bit holder block, said bit holder block having a bit holder block bore,
said bit holder comprising,
a front body portion and a generally cylindrical hollow shank portion extending from a rear of said front body portion,
said generally cylindrical hollow shank portion defining a thick walled annular side wall and including a first elongate slot through said thick side wall extending generally axially along said side wall from a distal end thereof and having a termination on said thick side wall between said distal end of said shank and said forward end of said shank,
a second internal elongate slot substantially diametrically opposite said shank from said first elongate slot, said second slot extending generally axially along said thick side wall and varying in width along its length, with an upper termination spatially related to said rear of said front body portion, and a lower termination spatially related to said distal end of said shank,
at least portions of said shank having a free standing diametrical dimension that is larger than a corresponding diametrical dimension of one of a cylindrical bit holder block bore and a non-locking tapered bit holder block bore, and the insertion of said bit holder shank in said bit holder block bore providing sufficient outward radial force by radial deflection of said portions of said shank adjacent said slots to retain said shank in either of said cylindrical and non-locking tapered bit holder block bores.