Drill/countersink assembly and method for producing countersunk holes

A countersink assembly adapted to be attached to a drill motor for drilling and countersinking a hole in a workpiece, comprising:

• an approximately cylindrical rear subassembly extending between a first end and a second opposed end and having a slot for a gage, wherein the outer diameter of the assembly defines an approximate first cylinder, the rear subassembly is mounted to a drill motor with an adaptor sleeve;
• an approximate first cylindrical body has a through hole for providing access to a chuck for tightening purposes and has two O-ring grooves where two O-rings are mounted on;
• said rear subassembly also comprises of a cylindrical vacuum sleeve that slides over the first cylindrical body with the O-rings mounted on it;
• an approximate cylinder front assembly having a main body, a coaxial spindle with a spindle shaft, wherein the front subassembly moves laterally in relation to said rear subassembly;
• the front subassembly also comprises of a spring with a bushing inside it entrapped in said main body;
• having quick change mechanism for removal of a nosepiece subassembly;
• and said nosepiece connected to countersink assembly vacuum system of a motor or connected to external source;
• an approximately cylindrical countersink cutter, operably connected to said drill motor, said coaxial spindle having a pin (533) inserted in a bore to accommodate a cutter shaft using a quick change mechanism to engage, having a body diameter with knurls and a hole (551) through, a pilot (548) and a set of cutting edges, wherein said rear subassembly is stationary;
• said coaxial spindle shaft mounts into said drill motor;
• said cutter shaft has a flat front end surface or edge (556) and a flat back end (565) along a longitudinal axis, an angular flat surface, and has a groove (562) to accommodate an O-ring (534);
• said front end surface or edge (556) of said cutter shaft coincides with a back end of said body diameter (558) of said cutter;
• said body diameter (558) has said knurls on a cylindrical body diameter surface;
• an angular flat surface locks into said pin of said coaxial spindle;
• and an intersection point (566) of the longitudinal axis and said cutting edges, when projected on to the longitudinal axis, is held in alignment at a substantially constant distance from the back end (565) surface of said cutter;
• and the distance between a front surface (557) of said coaxial spindle and the front surface (141) of said nose piece is constant and is equal to the distance between said front end surface or edge (556) of body diameter (558) flat surface and the center (567) of the radius when drawn between the tangent of said pilot diameter and said cutting edges;
• a subassembly consisting of a rear bracket (136) mounted on said stationary first cylindrical body, connected with an alignment rod (138) with screws to a front bracket (139) mounted on said main body;
• a speed controller (140) adjusted to be used as a stop mounted on said front bracket facing towards said rear bracket, said gage is used between said speed controller and said rear bracket for setting up the depth.