Minnesota Mining and Manufacturing Company

Ernest J Duwell

Gerald R Abrahamson

Ulrich Bloecher

Richard J Cosmano

John J Gagliardi

Jason A Chesley

David E Broberg

Charles H Houck

Richard J Cosniano

Coated abrasive article comprising a backing bearing on at least one major surface thereof erodible agglomerates and abrasive grains, wherein the erodible agglomerates consist essentially of a grinding aid and the erodible agglomerates are in the form of rods. The erodible agglomerates can be between or above or between and above the abrasive grains. The coated abrasive article of this invention utilizes a higher level of grinding aid than coated abrasive articles of the prior art.

Coated abrasive containing erodible agglomerates

Coated abrasive article comprising a backing bearing on at least one major surface thereof erodable agglomerates and abrasive grains, wherein the erodable agglomerates consist essentially of a grinding aid, and optionally, a binder. The erodable agglomerates can be above, between, or beneath the abrasive grains, or the erodable agglomerates can be above, between, and beneath the abrasive grains. The coated abrasive article of this invention utilizes a higher level of grinding aid than coated abrasive articles of the prior art.

Coated abrasive containing erodable agglomerates

A coated abrasive product comprising a backing bearing on at least one major surface thereof a make coat, a multiplicity of erodable agglomerates comprising a resinous binder and at least one inorganic filler material adhered to said make coat, a multiplicity of individual premium abrasive grains adhered to said make coat and disposed between said erodable agglomerates, a multiplicity of individual premium abrasive grains overlying said erodable agglomerates, and a size coat overlying said individual premium abrasive grains, said erodable agglomerates, and said make coat. The coated abrasive products of this invention abrade faster and endure longer than coated abrasive products using individual conventional abrasive grains in place of erodable agglomerates.

A rotary brush with removable brush elements is provided. The brush elements are disposed on a hub in a radial display. The brush elements include a resiliently flexible element which permits the brush to deflect at a greater angle from a rest position than the angle of deflection of the bristles of the brush from a normal position when the hub is rotated with the bristles in contact with the workpiece.

Method of making rotary brush with removable brush elements

Erodable agglomerates containing individual abrasive grains disposed in an erodable matrix comprising hollow bodies and a binder. The agglomerates are useful for coated abrasives and bonded abrasives. Abrasive products containing the agglomerates provide higher stock removal than abrasive products bearing a single layer of abrasive grains, since the erodable character of the agglomerates allows the sloughing off of spent individual abrasive grains during abrading operations and the exposing of new abrasive grains to the workpiece. The invention also provides a method of preparing the agglomerates of this invention.

Erodable agglomerates and abrasive products containing the same

A cutting element adapted to be used in a rotary drill bit is made by positioning in an appropriately shaped die cavity a quantity of a mixture of tungsten carbide and 4 to 11 percent cobalt in the shape of a crown for defining an outer surface for the tip portion of the cutting element using a pressure of less than about 600 pounds per square inch; positioning in the cavity a quantity of a mixture of tungsten carbide and 12 to 17 percent cobalt sufficient to form almost all of a base portion and at least an inner part of the tip portion for the cutting element; pressing the two quantities of the mixtures together and into the die at pressures in the range of about 10 to 15 tons per square inch; and sintering the pressed insert to form the cutting element.

Cutting element with wear resistant crown

Erodable agglomerates containing individual abrasive grains, a binder and matrix material selected from the group consisting of pulp suitable for making paper and derivatives thereof, wood flour, and vermiculate. The agglomerates are useful for coated abrasives and bonded abrasives. Abrasive products containing the agglomerates provide higher stock removal than abrasive products bearing a single layer of abrasive grains, since the erodable character of the agglomerates allows the sloughing off of spent individual abrasive grains during abrading operations and the exposing of new abrasive grains to the workpiece. The invention also provides a method of preparing the agglomerates of this invention.

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Saint Paul, MN, United States of America

Ernest J Duwell