Filamentary cutting tool containing solid microparticles and method of making it

Claim 2

IN A FILAMENTARY CUTTING TOOL FOR USE IN PERFORMING A CUTING OPERATIVE ON A WORKPIEC COMPRISING A MATRIX OF A SOLID AND RELATIVELY RIGID THERMOSETTING RESIN HAVING EMBEDDED THEREIN IN PLURALITY OF ELONGATED CUTTING FILAMENTS WITH A HARDNESS OF AT LEAST 250, AS MEASURED ON THE KNOOP SCALE, GREATER THAN THE WORKPIECE ALL EXTENDING IN SUBSTANTIALLY THE SAME DIRECTION WITH THE ENDS OF THE FILAMENTS BEING EXPOSED AT AT LEAST ONE SURFACE OF THE MATRIX TO CUT A WORKPEICE AND WHEREIN THE MATRIX WEARS AWAY IN USE TO KEEP THE ENDS, OF THE FILAMENTS EXPOSED, THE IMPROVEMENT COMPRISING A PLURALITY OF SOLID MICROPARTICLES SELECTED FROM THE GROUP CONSISTING OF GLASS. MICA, METAL, SAND AND CARBON EMBEDDED IN SAID MATRIX AND PRESENT IN AN AMOUNT AND SIZE TO ALLOW THE MATRIX TO WEAR AWAY IN USE AND KEEP THE ENDS OF SAID FILAMENTS EXPOSED WHILE AVOIDING FRAGMENTING AND SPALLING OF SAID MATRIX, THE MATRIX WITH THE MICROPARTICLES EMBEDDED THEREIN WEARING AWAY IN USE AT ABOUT THE SAME RATE AS THE CUTTING FILAMENTS.

Claim 3

A tool as defined in claim 1 in which the microparticles are glass spheres and the resin is an epoxy resin.

Claim 4

In a filamentary cutting tool for use in performing a cutting operation on a workpiece comprising a plurality of layers of cloth, a plurality of elongated cutting filaments having a hardness of at least 250, as measured on the Knoop scale, greater than the workpiece and with some disposed between each of said layers and all extending in substantially the same direction and disposed generally in planes paralleling said layers, and a matrix of a solid and relatively rigid thermosetting resin embedded in said layers and surrounding said filaments, the ends of said filaments being exposed to cut a workpiece whereby the matrix wears away in use to keep the ends of the filaments exposed, the improvement comprising a plurality of solid microparticles selected from the group consisting of glass, mica, metal, sand and carbon embedded in said matrix and present in an amount and size to allow the matrix to wear away in use and keep the ends of said filaments exposed while avoiding fragmenting and spalling of said matrix, the matrix with the microparticles embedded therein wearing away in use at about the same rate as the cutting filaments.

Claim 5

In a filamentary cutting tool for use in performing a cutting operation on a workpiece comprising a plurality of layers of cloth, a plurality of elongated cutting filaments having a hardness of at least 250, as measured on the Knoop scale, greater than the workpiece and with some disposed between each of said layers and all extending in substantially the same direction and disposed generally in planes paralleling said layers, and a matrix of a solid and relatively rigid thermosetting resin embedded in said layers and surrounding said filaments, the ends of said filaments being exposed to cut a workpiece whereby the matrix wears away in use to keep the ends of the filaments exposed, the improvement comprising a plurality of solid microparticles selected from the group consisting of glass, mica, metal, sand and carbon embedded in said matrix and present in an amount and size to allow the matrix to wear away in use and keep the ends of said filaments exposed while avoiding fragmenting and spalling of said matrix, the matrix with the microparticles embedded therein wearing away in use at about the same rate as the cutting filaments.

Claim 6

A tool as defined in claim 3 in which said microparticles are glass spheres and the resin is an epoxy resin.

Claim 7

In the method of making a filamentary cutting tool for use in performing a cutting operation on a workpiece including forming a composite comprising a cloth having spaced cutting filaments parallel to each other thereon and held together with a liquid thermosetting resin which when cured is solid and relatively rigid, heating said resin to form a composite sheet of cloth, filaments, and resin, forming a plurality of similar composite sheets, stacking said composite sheets with the filaments of all the sheets extending in the same direction, and bonding said sheets together to form a unitary block, the improvement comprising adding solid microparticles selected from the group consisting of glass, mica, metal, sand and carbon to the liquid thermosetting resin with the microparticles being present in an amount and size to allow the matrix to wear away in use and keep the ends of said filaments exposed while avoiding fragmenting and spalling of the matrix and the matrix with the microparticles embedded therein wearing away in use at about the same rate as the cutting filaments.

Claim 8

In the method of making a filamentary cutting tool for use in performing a cutting operation on a workpiece including forming a composite comprising a cloth having spaced cutting filaments parallel to each other thereon and held together with a liquid thermosetting resin which when cured is solid and relatively rigid, heating said resin to form a composite sheet of cloth, filaments, and resin, forming a plurality of similar composite sheets, stacking said composite sheets with the filaments of all the sheets extending in the same direction, and bonding said sheets together to form a unitary block, the improvement comprising adding solid microparticles selected from the group consisting of glass, mica, metal, sand and carbon to the liquid thermosetting resin with the microparticles being present in an amount and size to allow the matrix to wear away in use and keep the ends of said filaments exposed while avoiding fragmenting and spalling of the matrix and the matrix with the microparticles embedded therein wearing away in use at about the same rate as the cutting filaments.

Claim 9

The method as defined in claim 5 in which said block is cut successively in a direction across the filaments to form a plurality of tools from the block.

Claim 10

The method as defined in claim 5 in which said microparticles are glass spheres and said resin is an epoxy resin.

Claim 11

In a filamentary cutting tool comprising a matrix of a solid and relatively rigid thermosetting resin selected from the group consisting of polyimides and epoxy resins having embedded therein a plurality of elongated cutting filaments of a material selected from the group consisting of boron-coated tungsten, boron nitride, boron carbide, silicon carbide, titanium carbide, alumina, tungsten carbide, zirconia, titanium diboride and silica-substrate boron and all extending in substantially the same direction with the ends of the filaments being exposed at at least one surface of the matrix to cut a workpiece and wherein the matrix wears away in use to keep the ends of the filaments exposed, the improvement comprising a plurality of solid microparticles embedded in said matrix and present in an amount and size to allow the matrix to wear away in use and keep the ends of said filaments exposed while avoiding fragmenting and spalling of said matrix, said microparticles being a member selected from the group consisting of glass, sand, carbon mica and metal.

Claim 12

In a filamentary cutting tool comprising a matrix of a solid and relatively rigid thermosetting resin selected from the group consisting of polyimides and epoxy resins having embedded therein a plurality of elongated cutting filaments of a material selected from the group consisting of boron-coated tungsten, boron nitride, boron carbide, silicon carbide, titanium carbide, alumina, tungsten carbide, zirconia, titanium diboride and silica-substrate boron and all extending in substantially the same direction with the ends of the filaments being exposed at at least one surface of the matrix to cut a workpiece and wherein the matrix wears away in use to keep the ends of the filaments exposed, the improvement comprising a plurality of solid microparticles embedded in said matrix and present in an amount and size to allow the matrix to wear away in use and keep the ends of said filaments exposed while avoiding fragmenting and spalling of said matrix, said microparticles being a member selected from the group consisting of glass, sand, carbon mica and metal.

Claim 13

A tool as defined in claim 8 in which the solid microparticles are present in an amount of from about 15 to 75%, based upon the total weight of the resin and the microparticles, and the microparticles being of a size less than 50 microns.

Claim 14

A tool as defined in claim 8 in which the microparticles are glass microspheres and are present in an amount of from about 15 to about 30%, based upon the weight of the resin and the microspheres, and have an average particle size of from 20 to 30 microns.