Method and apparatus for cross-hole pressing to produce cutting inserts

Abstract

A method and apparatus for the cross-hole pressing of cutting inserts is disclosed whereby a green part is fabricated using metallurgical powder and an opening is imparted within the green part by placing the metallurgical powder about an oval-shaped core rod. Using a press with a uni-axial press motion, a core rod is placed within the cavity of a mold and metallurgical powder placed around the core rod and thereafter compressed to form a green part. The subject invention is also directed to an article formed utilizing such a process and the uni-axial press used to produce such an insert.

1 - 17 . (canceled)  
     
     
         18 . An article having an opening, wherein the article is formed using a uni-axial press motion having a die with a cavity extending therethrough along a pressing axis with a top ram and a bottom ram independently movable along the pressing axis within the cavity to define a compression region and furthermore a removable core rod insertable within a core bore through the cavity at the compression region in a direction perpendicular to the pressing axis, wherein the article is further formed by the steps of: 
 a) positioning the bottom ram within the cavity below the core bore and positioning the top ram outside of the cavity;    b) positioning the removable core rod through the core bore into the cavity;    c) filling the cavity with a predetermined amount of metallurgical powder;    d) positioning the metallurgical powder about the core rod to control the location of the hole after sintering;    e) moving the top ram down and moving the bottom ram up along a pressing axis against the metallurgical powder to uniformly compress the metallurgical powder about the core rod to produce a green part having a top and a bottom with walls formed therebetween to be sintered into a cutting insert, wherein the green part has an opening with a longitudinal axis perpendicular to the pressing axis of the die;    f) retracting the top ram and the bottom ram a predetermined amount to allow decompression of the green part;    g) retracting the core rod from within the cavity; and    h) ejecting the green part from the die.    
     
     
         19 . The article according to  claim 18  wherein the opening is centered within the green part.  
     
     
         20 . The article according to  claim 18  wherein the step of moving the top ram down and moving the bottom ram up comprises imparting to one or both of the top and bottom of the green part chip control features.  
     
     
         21 . The article according to  claim 20  wherein the chip control features are comprised of a rake face extending downwardly and away from the cutting edge and a plateau wall extending upwardly and away from the rake face, thereby defining an interrupted path that will promote chip control.  
     
     
         22 . The article according to  claim 20  wherein the chip control features are generally recessed in a planar region that is perpendicular to the pressing axis.  
     
     
         23 . The article formed by the steps according to  claim 18  including the further step of sintering the green part to form a cutting insert.  
     
     
         24 . The article according to  claim 23  wherein the step of moving the top ram down and moving the bottom ram up comprises imparting to one or both of the top and bottom of the green part chip control features.  
     
     
         25 . The article according to  claim 24  wherein the chip control features are comprised of a rake face extending downwardly and away from the cutting edge and a plateau wall extending upwardly and away from the rake face, thereby defining an interrupted path that will promote chip control.  
     
     
         26 . The article according to  claim 24  wherein the chip control features are generally recessed in a planar region that is perpendicular to the pressing axis  
     
     
         27 - 36 . (canceled)  
     
     
         37 . An article comprised of compacted metallurgical powder wherein the article has a body with a first lateral wall, an opposing second lateral wall and an adjacent first end wall and opposing second end wall therebetween, wherein the first lateral wall and second lateral wall define an article depth, wherein an opening with a peripheral wall extends about an axis through the depth of the article, wherein a parting line extends about the peripheral wall in a plane perpendicular to the axis, and wherein the article is shaped into a green part to be sintered into a cutting insert.  
     
     
         38 . The article according to  claim 37  wherein the opening is centered within the green part.  
     
     
         39 . The article according to  claim 37  wherein the article is a cutting insert that has been sintered from the green part.  
     
     
         40 - 42 . (canceled)  
     
     
         43 . An article having an opening, wherein the article is formed using a uni-axial press motion having a die with a cavity extending therethrough along a pressing axis with a top ram and a bottom ram independently movable along the pressing axis within the cavity to define a compression region and furthermore a removable core rod insertable within a core bore through the cavity at the compression region in a direction perpendicular to the pressing axis, wherein the article is further formed by the steps of: 
 a) positioning the bottom ram within the cavity below the core bore and positioning the top ram outside of the cavity;    b) positioning the removable core rod through the core bore such that the core rod extends completely through the cavity;    c) filling the cavity with a predetermined amount of metallurgical powder;    d) moving the die cavity relative to the top ram and the bottom ram to position the metallurgical powder about the core rod to control the location of the hole after sintering;    e) moving the top ram down and moving the bottom ram up along a pressing axis against the metallurgical powder to uniformly compress the metallurgical powder about the core rod to produce a green part having a top and a bottom with walls formed therebetween to be sintered into a cutting insert, wherein the green part has an opening with a longitudinal axis perpendicular to the pressing axis of the die, and wherein the step of moving the top ram down and the bottom ram up to compress the powder is further comprised of imparting chip control features to at least one of the top or the bottom of the green part;    f) retracting the top ram and the bottom ram a predetermined amount to allow decompression of the green part;    g) retracting the core rod from within the cavity; and    h) ejecting the green part from the die.