Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
201 words
A powder metallurgical method of constructing a cutter for a rolling cutter drill bit, said method comprising: providing a first powder consisting essentially of a mixture comprising a major proportion by volume of a powdered refractory compound and a minor proportion by volume of a powdered binder metal or alloy, providing a second powder comprising a powdered binder metal or alloy or a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in said first powder, forming said cutter of said first and said second powders; mixing said powders while forming said cutter and introducing into a first region of said cutter a mixture having a first preselected proportion of said first powder relative to said second powder, changing the relative proportions of said powders while mixing to introduce into a second region of said cutter a mixture having a second preselected proportion of said first powder relative to said second powder and a continuous gradient in the relative proportions of said powders between said regions; and densifying said powders into a solid cutter having a gradient in composition and properties from said first region to said second region.
Claim 2
Dependent Claim
201 words
A powder metallurgical method of constructing a cutter for a rolling cutter drill bit, said method comprising: providing a first powder consisting essentially of a mixture comprising a major proportion by volume of a powdered refractory compound and a minor proportion by volume of a powdered binder metal or alloy, providing a second powder comprising a powdered binder metal or alloy or a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in said first powder, forming said cutter of said first and said second powders; mixing said powders while forming said cutter and introducing into a first region of said cutter a mixture having a first preselected proportion of said first powder relative to said second powder, changing the relative proportions of said powders while mixing to introduce into a second region of said cutter a mixture having a second preselected proportion of said first powder relative to said second powder and a continuous gradient in the relative proportions of said powders between said regions; and densifying said powders into a solid cutter having a gradient in composition and properties from said first region to said second region.
Claim 3
Dependent Claim
47 words
The cutter constructing method of claim 1 wherein said first-named mixture of powders is located along at least a portion of the cutting surface of said cutter and said second-named mixture of powders is located around at least a portion of the interior surface of said cutter.
Claim 4
Dependent Claim
28 words
The cutter constructing method of claim 1 or claim 2 wherein said mixture of powders formed into the shape of said cutter is densified by hot isostatic pressing.
Claim 5
Dependent Claim
24 words
The cutter constructing method of claims 1, 2 or 3 further comprising machining a bearing surface in said interior surface of the densified cutter.
Claim 6
Dependent Claim
56 words
A method of constructing an abrasion and fracture resistant cutter for rock and underground formation cutting, said method comprising: securing a mold having a cavity substantially conforming to the desired exerior shape of said cutter; forming a cutter in said mold by the steps defined in claim 1, and separating said densified cutter from said mold.
Claim 7
Dependent Claim
59 words
The cutter construction method of claim 5 further comprising: forming at least one powdered metal cutting element into a precompacted form having at least two different regions with mixtures of metallic phases with a gradient therebetween; and placing at least one said cutting element into said mold cavity immediately prior to introducing said mixtures of powders into said mold.
Claim 8
Independent Claim
231 words
A method of forming a drilling bit insert having combined resistance to abrasion and bending stresses, said method comprising: providing a first powder consisting essentially of a mixture comprising a major proportion by volume of a powdered refractory compound and a minor proportion by volume of a powdered binder metal or alloy, providing a second powder comprising a powdered binder metal or alloy or a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in said first powder, providing a cutter insert mold, forming said insert of said first and said second powders; mixing said powders while forming said insert and introducing into the central portion of said mold a mixture having a first preselected proportion of said first powder relative to said second powder, changing the relative proportions of said powders while mixing to introduce into the outer portion of said mold a mixture having a second preselected proportion of said first powder relative to said second powder surrounding said central portion and extending to the outer surface of the insert formed therein and a continuous gradient in the relative proportions of said powders between said central portion and said outer portion; and densifying said mixtures of powders into a solid insert having a gradient in composition and properties from said central portion to the outer surface thereof.
Claim 9
Independent Claim
231 words
A method of forming a drilling bit insert having combined resistance to abrasion and bending stresses, said method comprising: providing a first powder consisting essentially of a mixture comprising a major proportion by volume of a powdered refractory compound and a minor proportion by volume of a powdered binder metal or alloy, providing a second powder comprising a powdered binder metal or alloy or a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in said first powder, providing a cutter insert mold, forming said insert of said first and said second powders; mixing said powders while forming said insert and introducing into the central portion of said mold a mixture having a first preselected proportion of said first powder relative to said second powder, changing the relative proportions of said powders while mixing to introduce into the outer portion of said mold a mixture having a second preselected proportion of said first powder relative to said second powder surrounding said central portion and extending to the outer surface of the insert formed therein and a continuous gradient in the relative proportions of said powders between said central portion and said outer portion; and densifying said mixtures of powders into a solid insert having a gradient in composition and properties from said central portion to the outer surface thereof.
Claim 10
Dependent Claim
53 words
The method of claim 7 wherein said central portion comprises a large volume fraction of said refractory compound and a small volume fraction of said binder metal or alloy, and said outer portion comprises a smaller volume fraction of said refractory compound and a larger volume fraction of said binder metal or alloy.
Claim 11
Dependent Claim
53 words
The method of claim 7 wherein said central portion comprises a smaller volume fraction of said refractory compound and a larger volume fraction of said binder metal or alloy, and said outer portion comprises a large volume fraction of said refractory compound and a small volume fraction of said binder metal or alloy.
Claim 12
Dependent Claim
36 words
The method of claim 7, 8 or 9 wherein said refractory compound comprises a transition metal carbide, and said binder metal or alloy comprises a metal selected from the group of iron, nickel cobalt, and copper.
Claim 13
Dependent Claim
34 words
The method of claim 7, 8 or 9 wherein said refractory compound comprises tungsten carbide, and said binder metal or alloy comprises a metal selected from the group of iron, nickel cobalt, and copper.
Claim 14
Independent Claim
215 words
A method of forming a drilling bit insert having combined resistance to abrasion and bending stresses, said method comprising: providing a first powder consisting essentially of a mixture comprising a major proportion by volume of a powdered refractory compound and a minor proportion by volume of a powdered binder metal or alloy, providing a second powder comprising a powdered binder metal or alloy of a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in said first powder, providing a cutter insert mold, forming said insert of said first and said second powders; mixing said powders while forming said insert and introducing into the tip portion of said mold a mixture having a first preselected proportion of said first powder relative to said second powder, changing the relative proportions of said powders while mixing to introduce into the base portion of said mold a mixture having a second preselected proportion of said first powder relative to said second powder and a continuous gradient in the relative proportions of said powders between said tip portion and said base portion; and densifying said mixtures of powders into a solid insert having a gradient in composition and properties from said tip portion to the base thereof.
Claim 15
Independent Claim
215 words
A method of forming a drilling bit insert having combined resistance to abrasion and bending stresses, said method comprising: providing a first powder consisting essentially of a mixture comprising a major proportion by volume of a powdered refractory compound and a minor proportion by volume of a powdered binder metal or alloy, providing a second powder comprising a powdered binder metal or alloy of a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in said first powder, providing a cutter insert mold, forming said insert of said first and said second powders; mixing said powders while forming said insert and introducing into the tip portion of said mold a mixture having a first preselected proportion of said first powder relative to said second powder, changing the relative proportions of said powders while mixing to introduce into the base portion of said mold a mixture having a second preselected proportion of said first powder relative to said second powder and a continuous gradient in the relative proportions of said powders between said tip portion and said base portion; and densifying said mixtures of powders into a solid insert having a gradient in composition and properties from said tip portion to the base thereof.
Claim 16
Dependent Claim
53 words
The method of claim 12 wherein said tip portion comprises a large volume fraction of said refractory compound and a small volume fraction of said binder metal or alloy, and said base portion comprises a smaller volume fraction of said refractory compound and a larger volume fraction of said binder metal or alloy.
Claim 17
Dependent Claim
35 words
The method of claim 12 or 13 wherein said refractory compound comprises a transition metal carbide, and said binder metal or alloy comprises a metal selected from the group of iron, nickel cobalt, and copper.
Claim 18
Dependent Claim
33 words
The method of claim 12 or 13 wherein said refractory compound comprises tungsten carbide, and said binder metal or alloy comprises a metal selected from the group of iron, nickel cobalt, and copper.
Claim 19
Dependent Claim
40 words
A method according to claim 1, 7 or 12 in which said powders are admixed with a fluid carrier to form at least one slurry prior to introduction into said mold cavity and said slurry sprayed into said mold cavity.
Claim 20
Dependent Claim
38 words
A method according to claim 1, 7 or 12 in which the powders are mixed and the composition selectively changed during introduction into the mold cavity, and said mixing and changing of composition is controlled by a microprocessor.
Claim 21
Dependent Claim
99 words
A method according to claim 1, 7 or 12 in which said second powder comprises a mixture comprising a powdered refractory material and a powdered binder metal or alloy, present in a lesser proportion by volume than in said first powder, additionally providing a third powder comprising a binder metal or alloy, and said powders being formed or introduced into a mold in compositions ranging from a mixture comprising said first powder in one region through intermediate mixtures comprising at least two of said powders in an intermediate region to a composition comprising said third powder in another region.