Milling machine tool holder

Claim 2

A collet having an open end central aperture for receiving a tool shank, said shank having a recess with a flat bottom and a width greater than half the diameter of the shank and a transversely extending beveled shoulder on the upper side thereof, and wherein said collet comprises a substantially tubular body having a cylindrical inner wall and having a tapered outer surface on its lower portion with diametrically opposite slit means extending lengthwise thereof to provide two contractible segments, the lower portion of one of the segments having an opening intermediate the axial ends thereof which radially extends from the tapered outer surface to the cylindrical inner wall; a locking insert disposed within said opening and having a close sliding fit therewith, said insert having a length substantially equal to the depth of the radial opening in said collet plus the depth of the recess in said tool shank, one end of said insert having a smooth tapered surface conforming to the tapered outer surface of said body, and the other end of said insert having a flat surface of breadth substantially equal to the width of the flat bottom of said recess for engagement therewith and having an adjacent surface complementary to the beveled shoulder on the upper side of said tool shank for mating therewith.

Claim 3

A tool holder for receiving a tool shank having a recess with a flat bottom and a width greater than half the diameter of the shank and a transversely extending beveled shoulder on the upper side thereof, said tool holder including a spindle means having a central bore with a tapered inner surface on its lower end, a collet having an open end central aperture and a substantially tubular body with a tapered outer surface on its lower portion including diametrically opposite slit means extending lengthwise along the diameter thereof to provide two circumferential segments, the lower portion of said collet being arranged to be radially contracted when the collet is drawn into the central bore of said spindle means, and drawing means on said spindle means for axially drawing said collet into the central bore thereof, the lower portion of one of the segments on said collet having a substantially rectangular opening intermediate the axial ends thereof which extends radially from the tapered outer surface to the central aperture thereof, and the longer dimension of said rectangular opening being normal to the longitudinal axis of said collet, said insert having a length substantially equal to the depth of the radial opening in said collet plus the depth of the recess in said tool shank, said insert having a flat inner end surface of breadth substantially equal to the width of the flat bottom of said recess and having an adjacent surface complementary to the beveled shoulder on the upper side of said tool shank, said insert having a smooth continuous outer end surface conforming with the tapered outer surface of the collet which contacts the wall of the bore of said spindle means, and the flat inner end surface of the insert being adapted to be fully seated in said recess with its adjacent edge against the beveled shoulder thereof when the collet is drawn up into said spindle means by said drawing means to thereby prevent the withdrawal of the tool.

Claim 4

A tool holder for receiving a tool shank having a recess with a flat bottom and a width greater than half the diameter of the shank and a transversely extending beveled shoulder on the upper side thereof, said tool holder including a spindle means having a central bore with a tapered inner surface on its lower end, a collet having an open end central aperture and a substantially tubular body with a tapered outer surface on its lower portion including diametrically opposite slit means extending lengthwise along the diameter thereof to provide two circumferential segments, the lower portion of said collet being arranged to be radially contracted when the collet is drawn into the central bore of said spindle means, and drawing means on said spindle means for axially drawing said collet into the central bore thereof, the lower portion of one of the segments on said collet having a substantially rectangular opening intermediate the axial ends thereof which extends radially from the tapered outer surface to the central aperture thereof, and the longer dimension of said rectangular opening being normal to the longitudinal axis of said collet, said insert having a length substantially equal to the depth of the radial opening in said collet plus the depth of the recess in said tool shank, said insert having a flat inner end surface of breadth substantially equal to the width of the flat bottom of said recess and having an adjacent surface complementary to the beveled shoulder on the upper side of said tool shank, said insert having a smooth continuous outer end surface conforming with the tapered outer surface of the collet which contacts the wall of the bore of said spindle means, and the flat inner end surface of the insert being adapted to be fully seated in said recess with its adjacent edge against the beveled shoulder thereof when the collet is drawn up into said spindle means by said drawing means to thereby prevent the withdrawal of the tool.

Claim 5

An accessory according to claim 1 wherein said insert has a substantially rectangular cross sectional shape with the long dimension adapted to extend at a right angle to the axis of the collet.

Claim 6

An accessory according to claim 3 wherein said insert has a substantially flat face extending throughout the side adapted to face the open end of the collet.

Claim 7

An accessory according to claim 4 wherein said insert has a rounded wall on the side opposite the flat face extending from one end edge of the flat face to the other end edge.