Tool bit

A tool bit comprising a shank including a cylindrical base portion having an axis and a diameter, an elongated end portion of generally cylindrical shape and having an axis extending coaxially with said axis of said base portion, and an outer cylindrical periphery extending for substantially the axial length of said end portion and with a constant diameter less than said diameter of said base portion, said end portion including therein a recess extending lengthwise of said end portion and being of right angle shape in a cross-section extending transversely of said end portion axis, said recess cross-section being defined by a long face extending in parallel spaced relation to a radius extending from said end portion axis and including an outer end at said cylindrical outer periphery and an inner end, and a short face extending from said inner end to said cylindrical outer periphery, and a connecting portion joining said end portion and said base portion and tapering from said base portion diameter to said end portion diameter, and a carbide insert brazed in said recess and having a transverse generally rectangular cross-section with a length extending along said short face and beyond said outer cylindrical periphery of said end portion, said carbide insert being sharpened to provide a cutting edge, and said carbide insert including an end portion including a flat exposed surface and an inner surface which is bonded to said shank and which has a first part extending in spaced generally parallel relation to said exposed surface and a second part which curves from said first part toward and intersects with said exposed surface.

A tool bit comprising a shank including a cylindrical base portion having an axis and a diameter, an elongated end portion of generally cylindrical shape and having an axis extending coaxially with said axis of said base portion, and an outer generally cylindrical periphery extending for substantially the axial length of said end portion and with a constant diameter less than said diameter of said base portion, said end portion including therein a recess extending lengthwise of said end portion and being of generally right angle shape in a cross-section extending transversely of said end portion axis, said recess cross-section being defined by a first face extending in generally parallel spaced relation to a radius extending from said end portion axis and including an outer end at said cylindrical outer periphery and an inner end, and a second face extending from said inner end to said cylindrical outer periphery, and a connecting portion joining said end portion and said base portion and tapering from said base portion diameter to said end portion diameter, and a carbide insert brazed in said recess and having a length extending along one of said faces and beyond said outer cylindrical periphery of said end portion, said carbide insert being sharpened to provide a cutting edge, and said carbide insert including an end portion, and an inner edge surface in engagement with the other of said faces of said recess in said end portion and an outer edge surface which extends parallel to said inner edge surface and from a shoulder adjacent to said end portion of said carbide insert.

A tool bit comprising a shank including a cylindrical base portion having an axis and a diameter and including an outer end and a void extending inwardly from said outer end and in spaced and parallel relation to said base portion axis for reducing an out of balance condition, and in a plane including the center of mass of said tool bit, an elongated end portion of generally cylindrical shape and having an axis extending coaxially with said axis of said base portion, and an outer cylindrical periphery extending for substantially the axial length of said end portion and with a constant diameter less than said diameter of said base portion, said end portion including therein a recess extending lengthwise of said end portion and being of right angle shape in a cross-section extending transversely of said end portion axis, said recess cross-section being defined by a long face extending in parallel spaced relation to a radius extending from said end portion axis and including an outer end at said cylindrical outer periphery and an inner end, and a short face extending from said inner end to said cylindrical outer periphery, and a connecting portion joining said end portion and said base portion and tapering from said base portion diameter to said end portion diameter, and a carbide insert brazed in said recess and having a transverse generally rectangular cross-section with a length extending along said short face and beyond said outer cylindrical periphery of said end portion, said carbide insert being sharpened to provide a cutting edge.

A tool bit comprising a shank fabricated of "Sheffield #20 T.G.P." steel and including a cylindrical base portion including an axis, a diameter, an outer end and a void extending inwardly from said outer end and in spaced and parallel relation to said base portion axis, and in a plane including the center of mass of said tool bit, an elongated end portion of generally cylindrical shape and having an axis extending coaxially with said axis of said base portion, and an outer cylindrical periphery extending for substantially the entire length of said end portion and having a constant diameter less than said diameter of said base portion, said end portion including therein a recess extending lengthwise of said end portion and being of right angle shape in a cross-section extending transversely of said end portion axis, said recess cross-section being defined by a long face extending in parallel spaced relation to a radius extending from said end portion axis and including an outer end at said cylindrical outer periphery and an inner end, and a short face extending from said inner end to said cylindrical outer periphery, and a connecting portion joining said end portion and said base portion and tapering from said base portion diameter to said end portion diameter, said connecting portion including an outwardly concave tapering surface having an exponential profile with a minimum radius adjacent said base portion and a maximum radius adjacent said end portion, said connecting portion also including a recess extension defined by a flat surface extending from said short face, and a curving surface extending from said long face, and an insert fabricated of carbide and having a transverse generally rectangular cross-section with a length extending along said short face and beyond said outer cylindrical periphery of said end portion, said insert including a main portion in said recess in said end portion of said shank and including an exposed flat surface, an inner flat surface brazed to said short face of said recess, an inner edge surface brazed to said long face of said recess, and an outer edge surface which extends parallel to said inner edge surface, said insert also including an end portion extending from said main portion and including a flat exposed surface extending from said exposed surface of said main portion and an inner surface which is brazed to said shank and which has a first part extending in spaced generally parallel relation to said exposed surface of said insert end portion and a second part which curves from said first part toward, and intersects with, said exposed surface of said insert end portion, said insert being sharpened to provide a cutting edge.