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.

1 . A method of drilling a port hole configuration in a single operation comprising:
 providing 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 comprising at least one insert attachment seat portion;   providing at least one first drilling member at the first end of the holder along the rotational axis of the holder;   attaching at least one drilling insert which is replaceable and non-indexable to the at least one insert seat attachment portion of the intermediate portion of the holder, the at least one drilling insert comprising a plurality of cutting surfaces opposite at least first, second and third insert register surfaces, with the first, second and third insert register surfaces corresponding with at least first, second and third seat attachment register surfaces formed in the intermediate portion of the tool holder,   causing rotation of the holder relative to a workpiece to drill a hole configuration, wherein the hole configuration includes a port taper section formed by the at least one drilling insert and a cylindrical hole portion formed by the at least one first drilling member, such that the cutting forms a port seal configuration in a single cutting operation.   
     
     
         2 . The method of  claim 1  wherein the at least one drilling insert comprises at least four cutting edges adapted to form a port seal in a single cutting operation. 
     
     
         3 . The method of  claim 2  wherein the at least four cutting edges comprise 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 for forming a seal angle, and a fourth cutting edge for forming a chamfer. 
     
     
         4 . The method of  claim 1  wherein at least two drilling inserts are attached to insert attachment seat portions formed in the intermediate portion of the tool holder in relative positions in the tool holder selected from the group consisting of symmetrically about the rotational axis of the holder or asymmetrically about the rotational axis of the holder. 
     
     
         5 . The method of  claim 1 , wherein the first seat attachment register surface are formed substantially parallel to or angled relative to the rotational axis of the tool. 
     
     
         6 . The method of  claim 1 , wherein the second seat attachment register surface are formed substantially perpendicular to or angled relative to the rotational axis of the tool. 
     
     
         7 . The method of  claim 1 , wherein the third seat attachment register surface are formed substantially parallel to or angled relative to the rotational axis of the tool. 
     
     
         8 . The method of  claim 1 , wherein the at least one drilling insert is attached so as to bias the insert against the first, second and third seat attachment register surfaces. 
     
     
         9 . The method of  claim 1 , wherein the first insert register surface and the second insert register surface of the at least one drilling insert are orthogonal or angled at greater or lesser than about 90 degrees. 
     
     
         10 . The method of  claim 1 , wherein the a cutting edge of the at least one drilling insert has an angle that shapes the outside wall of a spot face diameter of a formed port seal hole. 
     
     
         11 . The method of  claim 1 , wherein the at least one insert is formed from a blank of material, wherein the thickness of the blank is substantially less than the width or length. 
     
     
         12 . The method of  claim 1 , wherein the second insert register surface is formed to be perpendicular to or at an acute angle with a plane perpendicular to the rotational axis of the tool when mounted in the insert attachment seat portion. 
     
     
         13 . The method of  claim 1 , wherein the first drilling member is replaceable. 
     
     
         14 . The method of  claim 1  wherein the at least one drilling insert is positioned on an independent cartridge attachable to the at least one seat attachment portion of the holder, wherein the cartridge is adapted to permit radial and axial adjustment of said at least one drilling insert position relative to said holder and said first cutting member. 
     
     
         15 . The method of  claim 1  wherein a plurality of drilling inserts are attached to a plurality of insert attachment seat portions at the intermediate portion of the holder, such that the plurality of drilling inserts comprises cutting edges that together form a port seal hole configuration, with 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. 
     
     
         16 . The method of  claim 1 , further comprising forming an identification ridge in the hole configuration. 
     
     
         17 . The method of  claim 1 , wherein the first, second and third seat attachment register surfaces mating with the at least first, second and third insert register surfaces of the at least one insert are formed wherein with the first seat attachment register surface forming a bottom seating surface for the at least one drilling insert, a second seat attachment register surface forming a radially inward side seating surface for the at least one drilling insert, and a third seat attachment register surface forming a back seating surface for the at least one drilling insert in relation to the first seat attachment register surface and the second seat attachment register surface. 
     
     
         18 . A method of forming a port seal hole configuration in a workpiece, comprising providing 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 comprising at least two insert attachment seat portions; a first cutting member at the first end of the holder; and at least two drilling inserts attachable to the insert seat attachment portions of the intermediate portion of the holder for forming a port seal in a single cutting operation, the drilling inserts each comprising a cutting face side opposite a register face side, and a plurality of side surfaces therebetween, the plurality of side surfaces comprising a first register side surface forming a bottom seating surface of each insert, a second register side surface forming a second seating surface of each insert, and each insert comprising 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 for forming a seal angle, and a fourth cutting edge for forming a chamfer, wherein each drilling insert is replaceable and non-indexable. 
     
     
         19 . The method of  claim 18 , wherein the at least one insert is formed from a blank of material, wherein the thickness of the blank is substantially less than the width or length. 
     
     
         20 . A drilling insert for use with 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 second end comprising a shank portion, and the intermediate portion comprising at least one insert attachment seat portion wherein the drilling insert is formed from a blank of material with the thickness of the blank being substantially less than the width or length, the drilling insert comprising a plurality of cutting surfaces opposite at least first, second and third insert register surfaces and a plurality of cutting surfaces for forming a port taper section of a port seal hole configuration.