Tool holder for metal drilling, threading and milling machines

A tool holder for metal drilling, threading, and milling machines that enables deviations in a work piece of up to one mm to be absorbed without forcing or breaking the tool, wherein the tool holder is made up of three parts comprising:

• a first or input part that has a conical body with a coupling to a machine, that incorporates a first plate in a base thereof, the first plate being provided with two horizontally arranged diametrically opposed mounting holes, one on each side of an axial appendage that has concave sides and slots at the ends thereof for fitting a circular spring, while a surface of the axial appendage has several small threaded holes to allow the three parts to be joined together, the first or input part is configured to transmit a rotation received from the machine via the first plate to a second or intermediate part,
• the second or intermediate part in the form of a second plate with a large axial passage in which the axial appendage of the first part is seated, the second plate having four diametrically opposed through-holes and arranged in pairs in a cross shape and into which two perpendicular bolts or shafts are screwed on one face of the second plate such that the ends of these two perpendicular bolts or shafts are seated in the mounting holes of the first part, while the two other perpendicular bolts or shafts are screwed into the opposite face of the second plate to be joined via the ends thereof to a third or output part, the second or intermediate part receives the rotation transmitted from the first or input part and rotates with axial clearance in a first radial direction perpendicular to a longitudinal axis of the tool holder defining a shaft axis,
• the third or output part in the form of a third plate with a tubular axial passage that projects from an outer face of the third plate and is intended to be coupled to the tool, while an inner face of the third plate has two vertically arranged diametrically opposed mounting holes that are intended to receive the ends of two perpendicular shafts or bolts of the second part, with two oval appendages formed on the edge of the tubular axial passage between the two vertically arranged diametrically opposed mounting holes, the oval appendages having lateral slots intended to be coupled to the concave sides of the axial appendage of the first part, with the set of oval appendages being retained by the circular spring of the first part, which keeps the oval appendages centered and aligned, the second or intermediate part transmits the rotation transmitted from the first or input part to the third or output part, third or output part rotates with axial clearance in a second radial direction perpendicular to the longitudinal axis of the tool holder and orthogonal to the first radial direction, providing the rotary movement with axial clearance in both radial directions, and
• a ring that is fastened using screws in the threaded holes of the axial appendage of the first part, thereby joining the three parts together and thus closing a plate packet defined by the three parts, with the second or intermediate plate being configured to provide positional adjustment between the first or input part and the third or output part so as to maintain alignment about the longitudinal axis of the tool holder.