High-speed metal cutting method and self-sharpening tool constructions and arrangements implementing same
AssigneeGeneral Electric Company
InventorsMinyoung Lee, William R. Reed, Jr., Lawrence E. Szala
Life of this patent
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Abstract
A self-sharpening refractory metal cutting tool presenting an overhanging cutting portion, i.e. a flange, or ledge, of width equal to (or slightly greater than) the depth of the cut to be taken and maximum thickness equal to tolerable tool flank wear is disclosed. This tool construction has special utility in a novel high-speed cutting method in which only the tool flange does the cutting in which operation the flange is worn away with the wear progressing lengthwise of the flange during which time the flange sequentially performs a roughing cut and then a finishing cut in a single pass.
Claims31
The high-speed, metal cutting method which comprises the steps of:
- (a) providing and rigidly mounting a cutting tool adjacent a metal workpiece, said cutting tool having as part thereof a cantilevered longitudinally-extending cutting element at least 1/4 inch in length, having a thickness dimension in the range of from 20 mils to 80 mils, being substantially uniform in transverse cross-section along its length and having a flank face and a rake face with said flank face being a substantially uniform distance in the range of from 20 mils to 80 mils from any support for said cutting element;
- (b) causing relative rotation to occur between said cutting element and said workpiece;
- (c) bringing the leading end of said cutting element against said workpiece;
- (d) providing a clearance angle of about one degree or less between said flank face and said workpiece thereby having the trailing end of said cutting element out of contact with said workpiece and
- (e) advancing said tool and maintaining contact between the leading end of said cutting element and said workpiece as metal is removed from said workpiece during the relative rotation and said cutting element is consumed along the length thereof with a new leading end being generated as wear occurs.
In a cutting tool arrangement in which a tool insert of refractory material is rigidly held in a tool holder, said tool holder being adapted to bring said tool insert into contact with a metal workpiece to alter the shape thereof by the removal of metal therefrom, the improvement wherein the tool insert is a flat plate of substantially uniform thickness in the range of from 20 mils to 80 mils, said plate being fixedly disposed on a separate support therefor in overhanging relationship therewith to define a cutting element portion of said plate having a flank face of said cutting element portion located a substantially uniform thickness in the range of from 20 mils to 80 mils from said support, said flank face being defined at its upper extremity by a sharp edge, said cutting element portion being at least 1/4 inch in length with the thickness of said cutting element being in the range of from 20 mils to 80 mils whereby during use as tool wear occurs consuming said cutting element along its length, new edges are generated on said cutting element at the leading end thereof where the cutting element consumption occurs and new short lengths of said sharp edge are exposed, a new edge together with a newly exposed short length become the leading end of said cutting element.
In a cutting tool arrangement in which a tool insert of refractory material is rigidly held in a tool holder, said tool holder being adapted to bring said tool insert into contact with a metal workpiece to alter the shape thereof by the removal of metal therefrom, the improvement wherein the tool insert is a multi-sided body having as at least one side thereof a longitudinally-extending portion of substantially uniform thickness in the range of from 20 mils to 80 mils, said tool insert being fixedly disposed in the tool holder on a separate support therefor with said portion in overhanging relationship with said support to define a cutting element having the flank face thereof located at a substantially uniform distance in the range of from 20 mils to 80 mils from said support, said flank face being defined at its upper extremity by a sharp edge, said cutting element being at least 1/4 inch in length and of substantially uniform transverse cross-section along said length with the maximum thickness of said cutting element being in the range of from 20 mils to 80 mils whereby during use as tool wear occurs consuming said cutting element along its length, new edges are generated on said cutting element at the leading end thereof where the cutting element consumption occurs and new short lengths of said sharp edge are exposed, a new edge together with a newly exposed short length become the leading end of said cutting element.
A cutting tool insert of refractory material comprising in combination a longitudinally-extending cutting element presenting the flank face for said tool insert and means for supporting said cutting element formed integrally therewith, said cutting element being in overhanging relationship to said support means with said flank face located a substantially uniform distance in the range of from 20 mils to 80 mils from said support means, said flank face being defined at its upper extremity by a sharp edge, said cutting element being at least 1/4 inch in length and of substantially uniform transverse cross-section along said length with a thickness dimension in the range of from 20 mils to 80 mils, said support means being in the shape of a right circular cylinder and said cutting element being in the form of a ledge of generally rectangular transverse cross-section extending along the upper edge of said support means, whereby as tool wear occurs during use said cutting element is consumed along its length generating new edges where the cutting element consumption occurs and exposing new short lengths of said sharp edge adjacent thereto.
Dependencies are inferred from the claim text.