Drilling tool and method for producing port seals

Abstract

The present invention provides a new drilling tool useful in machining hydraulic port seals for fluid power ports. The drilling tool drills the port hole to size in a solid material for the minor thread diameter in combination with forming the port in a single operation. The drilling tool has a tool holder having a rotational axis, a first drilling insert having cutting surfaces on a first side and a mounting surface on a second side, at least one second drilling insert having a predetermined cutting surface portion and a mounting portion which is mounted on the holder at a location from the rotational axis of the holder. The at least one second drilling insert has first and second portions which engage and machine a work piece in a drilling operation to form a spot face and a seal form.

What is claimed is:  
     
         1 . A drilling tool comprising:
 a tool holder having a first end, a second end, and an intermediate portion between the first end and the second end, and a rotational axis therethrough, the second end comprising a shank portion, and the intermediate portion comprises at least one insert attachment seat portion;   at least one first drilling member provided at the first end of the holder;   at least one second drilling insert attached to the at least one insert seat attachment portion of the intermediate portion of the holder, the second drilling insert comprising a first cutting edge generally parallel to the rotational axis of the tool for forming the inner diameter of a counterbore, a second cutting edge generally perpendicular to the first cutting edge for forming a bottom surface or spotface of the counterbore, a third cutting edge formed transverse to the rotational axis of the cutting tool for forming a seal angle, and a fourth cutting edge formed transverse to the rotational axis of the cutting tool for forming a chamfer, and having first, second and third register surfaces, and wherein the seat attachment portion has first, second and third register surfaces that mate with corresponding register surfaces of the at least one second drilling insert; and wherein the at least one second insert is selectively replaceable and non-indexable.   
     
     
         2 . The drilling tool of  claim 1 , wherein the at least one first drilling member is non-indexable. 
     
     
         3 . The drilling tool of  claim 1 , wherein a plurality of second drilling inserts are attached to a plurality of insert attachment seat portions at the intermediate portion of the holder, such that each drilling drill insert comprises at least four cutting edges adapted to form a port seal hole configuration in a single cutting operation, with the at least four cutting edges including a first cutting edge for forming the diameter of a counterbore, a second cutting edge for forming a bottom surface or spotface of the counterbore, a third cutting edge formed for forming a seal angle, and a fourth cutting edge for forming a chamfer. 
     
     
         4 . The drilling tool of  claim 1 , wherein the at least one drilling insert is formed in a generally rectangular plate form, and the at least one insert seat attachment portion precisely mounts the drilling insert at the intermediate portion of the holder in relation to the rotational axis of holder. 
     
     
         5 . The drilling tool of  claim 1 , the position of the insert seat attachment portion is rotated below the location of the at least one first drilling member. 
     
     
         6 . The drilling tool of  claim 1 , wherein the at least one second insert is a full form insert to cut around corners and chamfers and blend all surfaces. 
     
     
         7 . A drilling tool comprising:
 a holder having a first end, a second end, and an intermediate portion between the first end and the second end, and a rotational axis, the intermediate portion of the holder comprising at least two insert attachment portions having first, second and third register surfaces formed into the intermediate portion of the holder;   at least one first drilling insert attached to the first end of the holder; and a port cutting insert attachable to the each insert attachment portion of the intermediate portion of the holder, which in conjunction with the first cutting member form a port seal including formation of both the minor thread diameter and port form in a single cutting operation, the port cutting inserts comprising a first cutting edge for forming the diameter of counterbore, a second cutting edge for forming a bottom surface or spotface of the counterbore, a third cutting edge for forming a seal angle, and a fourth cutting edge for forming a chamfer, wherein the port cutting inserts mate to the first, second and third register surfaces of the insert attachment portions formed on the intermediate portion of the holder, and are replaceable and non-indexable.   
     
     
         8 . The tool of  claim 7 , wherein the first register surfaces of the two insert attachment portions are formed substantially parallel to or angled relative to the rotational axis of the tool. 
     
     
         9 . The tool of  claim 7 , wherein the second register surfaces of the two insert attachment portions are formed substantially perpendicular to or angled relative to the rotational axis of the tool. 
     
     
         10 . The tool of  claim 7 , wherein the third register surfaces are formed substantially parallel to or angled relative to the rotational axis of the tool. 
     
     
         11 . The tool of  claim 7 , wherein the port cutting inserts are attached so as to bias the insert against the first, second and third register surfaces of the insert attachment portions. 
     
     
         12 . The tool of  claim 7 , wherein the angle between the first insert register surface and the second insert register surface of the insert attachment portions are orthogonal or angled at greater or lesser than about 90 degrees. 
     
     
         13 . The method of  claim 7 , wherein the port insert is formed from a blank of material, wherein the thickness of the blank is substantially less than the width or length. 
     
     
         14 . The tool of  claim 7 , wherein the first drilling member is replaceable and non-indexable. 
     
     
         15 . The tool of  claim 7 , wherein the port insert is formed in a generally rectangular plate form, and the at least one insert seat attachment portion precisely mounts the drilling insert at the intermediate portion of the holder in relation to the rotational axis of holder. 
     
     
         16 . A drilling tool comprising:
 a tool holder having a first end, a second end, and an intermediate portion between the first end and the second end, and a rotational axis, the second end comprising a shank portion, and the intermediate portion comprises at least one insert attachment seat portion;   at least one first drilling member provided at the first end of the holder;   at least one second drilling insert attached to the at least one insert seat attachment portion of the intermediate portion of the holder, the second drilling insert comprising a first cutting edge generally parallel to the rotational axis of the tool for forming the inner diameter of a counterbore, a second cutting edge generally perpendicular to the first cutting edge for forming a bottom surface or spotface of the counterbore, a third cutting edge formed transverse to the rotational axis of the cutting tool for forming a seal angle, and a fourth cutting edge formed transverse to the rotational axis of the cutting tool for forming a chamfer, wherein the at least one second drilling insert is a full form insert to cut around corners and chamfers and blend all surfaces, and having first, second and third register surfaces, and wherein the at least one insert seat attachment portion has first, second and third register surfaces formed into the intermediate portion of the holder that mate with corresponding register surfaces of the at least one second drilling insert; and wherein the at least one second insert is replaceable and non-indexable.   
     
     
         17 . The tool of  claim 16 , wherein the first drilling member is replaceable and non-indexable. 
     
     
         18 . The tool of  claim 16 , wherein a plurality of second drilling inserts are attached to a plurality of insert attachment seat portions at the intermediate portion of the holder, such that each drilling drill insert comprises at least four cutting edges adapted to form a port seal hole configuration in a single cutting operation, with the at least four cutting edges including a first cutting edge for forming the diameter of a counterbore, a second cutting edge for forming a bottom surface or spotface of the counterbore, a third cutting edge formed for forming a seal angle, and a fourth cutting edge for forming a chamfer. 
     
     
         19 . The tool of  claim 16 , wherein the at least one drilling insert is formed in a generally rectangular plate form, and the at least one insert seat attachment portion precisely mounts the drilling insert at the intermediate portion of the holder in relation to the rotational axis of holder. 
     
     
         20 . The tool of  claim 16 , the position of the insert seat attachment portion is rotated below the location of the at least one first drilling member. 
     
     
         21 . The tool of  claim 16 , wherein the first cutting edge of the at least one second drilling insert has a second angle that shapes the outside wall of the spot face diameter of a formed port seal hole. 
     
     
         22 . The drill tool of  claim 16 , further comprising at least one coolant hole formed in the holder to direct coolant toward the cutting edges of the at least one second insert.