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US4662348A Expired / Lapsed US ⏱️ 0.0 years remaining

Burnishing diamond

Assignee: SII MegaDiamond Inc
•
Filing: 1985-06-20
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Granted: 1987-05-05
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Expires: 2005-06-20
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Abstract

Abstract Scratch-free polished diamond is obtained by rubbing a surface of the diamond to be polished against a smooth complementary diamond surface with sufficient pressure and velocity to heat the surface being polished above the spontaneous thermal degradation temperature of the diamond. Such a method can be used to burnish diamond-on-diamond bearings in as little as ten minutes as compared with up to three weeks by prior polishing techniques. Excessive thermal degradation of the diamond is avoided by cooling the surface being polished, preferably by cooling intermittently. The same techniques are usable for other superhard material such as cubic boron nitride.

Inventors

  • 👤 David R. Hall
  • 👤 H. Tracy Hall, Jr.
  • 👤 Christian L. Lauridsen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 23:05
CPC Classifications
B; B24; B24B; B24B1/00; F; F16; F16C; F16C33/00; F16C33/02; F16C33/04; F16C33/043; F16C2300/00; F16C2300/02

Claims Analysis

Total Claims: 30
Claim 1
Independent Claim 36 words
A method for burnishing superhard material comprising moving a surface of the superhard material to be polished along a substantially grit-free complementary superhard material surface at a sufficient pressure and velocity to polish the superhard material.
Claim 2
Independent Claim 36 words
A method for burnishing superhard material comprising moving a surface of the superhard material to be polished along a substantially grit-free complementary superhard material surface at a sufficient pressure and velocity to polish the superhard material.
Claim 3
Independent Claim 47 words
A method for polishing polycrystalline superhard material comprising intermittently applying frictional energy to an area of a surface to be polished larger than the area of a crystal at the surface for a sufficient interval to thermally degrade a uniform layer of such area of the surface.
Claim 4
Independent Claim 47 words
A method for polishing polycrystalline superhard material comprising intermittently applying frictional energy to an area of a surface to be polished larger than the area of a crystal at the surface for a sufficient interval to thermally degrade a uniform layer of such area of the surface.
Claim 5
Independent Claim 46 words
A method for polishing superhard material comprising rubbing a surface of the superhard material to be polished against a smooth complementary polycrystalline superhard material surface with sufficient pressure and velocity to heat the surface being polished above the spontaneous thermal degradation temperature of the superhard material.
Claim 6
Independent Claim 46 words
A method for polishing superhard material comprising rubbing a surface of the superhard material to be polished against a smooth complementary polycrystalline superhard material surface with sufficient pressure and velocity to heat the surface being polished above the spontaneous thermal degradation temperature of the superhard material.
Claim 7
Independent Claim 88 words
A method for polishing superhard material comprising: rubbing a surface of the superhard material to be polished against a complementary superhard material surface, flowing cooling liquid on at least one of the surfaces; and controlling ##EQU5## between a lower limit below which no thermal degradation of the superhard material occurs and an upper limit above which film boiling of liquid occurs, wherein P is pressure between the superhard material surfaces, v is the velocity between the surfaces and dQ/dt is the rate of heat extraction by the liquid.
Claim 8
Independent Claim 88 words
A method for polishing superhard material comprising: rubbing a surface of the superhard material to be polished against a complementary superhard material surface, flowing cooling liquid on at least one of the surfaces; and controlling ##EQU5## between a lower limit below which no thermal degradation of the superhard material occurs and an upper limit above which film boiling of liquid occurs, wherein P is pressure between the superhard material surfaces, v is the velocity between the surfaces and dQ/dt is the rate of heat extraction by the liquid.
Claim 9
Independent Claim 69 words
A method for polishing diamond comprising rubbing a surface of diamond to be polished against a smooth complementary diamond surface at a sufficient pressure and velocity and within a range of cooling (a) sufficient to elevate the temperature of a surface layer above the temperature where diamond spontaneously transforms to non-diamond; and (b) insufficient to heat the diamond below the surface layer to the thermal degradation temperature of diamond.
Claim 10
Independent Claim 69 words
A method for polishing diamond comprising rubbing a surface of diamond to be polished against a smooth complementary diamond surface at a sufficient pressure and velocity and within a range of cooling (a) sufficient to elevate the temperature of a surface layer above the temperature where diamond spontaneously transforms to non-diamond; and (b) insufficient to heat the diamond below the surface layer to the thermal degradation temperature of diamond.
Claim 11
Independent Claim 49 words
A method for polishing superhard material comprising: rubbing a surface to be polished against a smooth complementary superhard material surface with sufficient pressure and velocity to polish the superhard material; and intermittently cooling the surface of the superhard material being polished for inhibiting thermal degradation of the superhard material.
Claim 12
Independent Claim 49 words
A method for polishing superhard material comprising: rubbing a surface to be polished against a smooth complementary superhard material surface with sufficient pressure and velocity to polish the superhard material; and intermittently cooling the surface of the superhard material being polished for inhibiting thermal degradation of the superhard material.
Claim 13
Independent Claim 44 words
A method for polishing superhard material comprising alternately: rubbing a surface of the superhard material to be polished against a smooth complementary superhard material surface in the substantial absence of discrete superhard material particles; and cooling the surface being polished for inhibiting thermal degradation.
Claim 14
Independent Claim 44 words
A method for polishing superhard material comprising alternately: rubbing a surface of the superhard material to be polished against a smooth complementary superhard material surface in the substantial absence of discrete superhard material particles; and cooling the surface being polished for inhibiting thermal degradation.
Claim 15
Independent Claim 41 words
A method for finishing a set of complementary superhard material surfaces comprising rubbing the surfaces together without intervening abrasive at a sufficient pressure and velocity to burnish a portion of each of the superhard material surfaces to a smooth scratch-free surface.
Claim 16
Independent Claim 41 words
A method for finishing a set of complementary superhard material surfaces comprising rubbing the surfaces together without intervening abrasive at a sufficient pressure and velocity to burnish a portion of each of the superhard material surfaces to a smooth scratch-free surface.
Claim 17
Independent Claim 44 words
A method for polishing diamond comprising moving the diamond along a rigid complementary diamond surface with a Pv of at least 7 kilowatts per square centimeter, where P is pressure between the diamond and the complementary surface and v is the velocity of movement.
Claim 18
Independent Claim 44 words
A method for polishing diamond comprising moving the diamond along a rigid complementary diamond surface with a Pv of at least 7 kilowatts per square centimeter, where P is pressure between the diamond and the complementary surface and v is the velocity of movement.
Claim 19
Independent Claim 65 words
A method for burnishing superhard material comprising: rubbing the superhard material against a smooth complementary superhard material surface in the substantial absence of discrete superhard material particles with sufficient pressure and velocity to burnish the superhard material surface, the complementary surface including a plurality of recessed discontinuities; and introducing sufficient liquid coolant in the discontinuities for inhibiting thermal degradation of the superhard material being burnished.
Claim 20
Independent Claim 65 words
A method for burnishing superhard material comprising: rubbing the superhard material against a smooth complementary superhard material surface in the substantial absence of discrete superhard material particles with sufficient pressure and velocity to burnish the superhard material surface, the complementary surface including a plurality of recessed discontinuities; and introducing sufficient liquid coolant in the discontinuities for inhibiting thermal degradation of the superhard material being burnished.
Claim 21
Independent Claim 57 words
A method for finishing a bearing having smooth complementary polycrystalline diamond surfaces comprising running the diamond surfaces against each other at a sufficient pressure P and velocity v that the product Pv is greater than the maximum Pv of the bearing in service and sufficient to transform a portion of each diamond surface from diamond to non-diamond.
Claim 22
Independent Claim 57 words
A method for finishing a bearing having smooth complementary polycrystalline diamond surfaces comprising running the diamond surfaces against each other at a sufficient pressure P and velocity v that the product Pv is greater than the maximum Pv of the bearing in service and sufficient to transform a portion of each diamond surface from diamond to non-diamond.
Claim 23
Independent Claim 71 words
A method for finishing superhard material comprising the steps of: moving the surface of the superhard material against a smooth complementary superhard material surface at a selected pressure and velocity; sensing the friction force between the surfaces at the selected pressure and velocity; and after the friction force has decreased from a maximum at the selected pressure and velocity, increasing the product of pressure times velocity to a larger selected value.
Claim 24
Independent Claim 71 words
A method for finishing superhard material comprising the steps of: moving the surface of the superhard material against a smooth complementary superhard material surface at a selected pressure and velocity; sensing the friction force between the surfaces at the selected pressure and velocity; and after the friction force has decreased from a maximum at the selected pressure and velocity, increasing the product of pressure times velocity to a larger selected value.
Claim 25
Independent Claim 51 words
A method for finishing a fluid cooled diamond-on-diamond bearing comprising running the bearing at ##EQU6## at least two times the ##EQU7## in its intended service where P is the bearing pressure, v is the linear velocity of the bearing, and dQ/dt is the rate of heat extraction by the fluid coolant.
Claim 26
Independent Claim 51 words
A method for finishing a fluid cooled diamond-on-diamond bearing comprising running the bearing at ##EQU6## at least two times the ##EQU7## in its intended service where P is the bearing pressure, v is the linear velocity of the bearing, and dQ/dt is the rate of heat extraction by the fluid coolant.
Claim 27
Independent Claim 51 words
A method for polishing diamond comprising: rubbing a surface of the diamond to be polished against a complementary diamond surface with a sufficient pressure and velocity to polish the surface of the diamond; and maintaining the temperature of the diamond being polished higher than the temperature of the complementary diamond surface.
Claim 28
Independent Claim 51 words
A method for polishing diamond comprising: rubbing a surface of the diamond to be polished against a complementary diamond surface with a sufficient pressure and velocity to polish the surface of the diamond; and maintaining the temperature of the diamond being polished higher than the temperature of the complementary diamond surface.
Claim 29
Dependent Claim 14 words
A method as recited in claim 14 comprising selectively heating the diamond being polished.
Claim 30
Dependent Claim 14 words
A method as recited in claim 14 comprising selectively cooling the complementary diamond surface.

References Cited (Backward Citations)

US2931351A Cited
US3436868A Cited
US3698513A Cited
US3886695A Cited
US3902283A Cited
US4370835A Cited
US4401876A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-05-04 1990-11-03 1991-05-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-05-04 1994-11-03 1995-05-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-05-04 1998-11-03 1999-05-05 $7700.00 Window Closed / Lapsed

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