US3970174A
Expired / Lapsed
US
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Low wear disk brake assembly
Assignee: Lockheed Martin Tactical Systems Inc
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Filing: 1975-05-15
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Granted: 1976-07-20
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Expires: 1995-05-15
Abstract
Abstract A low wear disk brake assembly has a rotatable body and a fixed axle rotatably supporting the body. A stack of disks having splined portions are aligned alternatingly relative to the axle in the body with each disk characterized by being made from graphite and/or carbon materials such that the disks have flexural strength of greater than 5000 psi and an average interlaminar spacing of crystalline and amorphous carbon of not more than 3.39 angstrom units at 15°C.
Inventors
- 👤 Fred P. Kirkhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:19
CPC Classifications
F; F16; F16D; F16D69/00; F16D69/02; F16D69/023; C; C01; C01B; C01B32/00; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/521; F16D55/00; F16D55/24; F16D55/26; F16D55/36; F16D55/40; F16D65/00; F16D65/02; F16D65/12; F16D65/121; F16D65/125; F16D65/126; F16D2055/0004; F16D2055/0058; F16D2065/13; F16D2065/1304; F16D2065/1312
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
82 words
A low wear disk brake comprising: a disk characterized by being made from a carbon base material, a flexural strength of greater than 5,000 psi, said disk having a density greater than 1.40 grams per cc, and impact strength greater than 5 inch pounds per inch, an amount of carbon or graphite of at least about 75 percent of the total disk volume, and an average interlaminar spacing of crystalline and amorphous carbon of not more than 3.39 angstrom units at 15°C.
Claim 2
Dependent Claim
82 words
A low wear disk brake comprising: a disk characterized by being made from a carbon base material, a flexural strength of greater than 5,000 psi, said disk having a density greater than 1.40 grams per cc, and impact strength greater than 5 inch pounds per inch, an amount of carbon or graphite of at least about 75 percent of the total disk volume, and an average interlaminar spacing of crystalline and amorphous carbon of not more than 3.39 angstrom units at 15°C.
Claim 3
Dependent Claim
28 words
A disk brake as in claim 1 wherein said interlaminar spacing ranges from about 3.35 to about 3.39 angstrom units and a coefficient of friction greater than 0.10.
Claim 4
Dependent Claim
22 words
A disk brake as in claim 2 wherein said disk is made by heating a carbon based material in excess of 2,500°C.
Claim 5
Dependent Claim
27 words
A disk brake as in claim 3 wherein said disk is made by repeated impregnation and heating steps, the final heating step being in excess of 2,500°C.
Claim 6
Dependent Claim
40 words
A disk brake as in claim 1 wherein said disk has thermal conductivity of greater than 0.04 cal/sec/cm 2 /°C and a friction coefficient of at least 0.08 between adjacent disks over an operating range of from -65°F to 4,000°F.
Claim 7
Dependent Claim
24 words
A disk brake as in claim 5 wherein said disk has an impact strength of from 5 to about 55 inch pounds per inch.
Claim 8
Dependent Claim
111 words
A low wear disk brake assembly comprising: a rotatable body, a fixed axle rotatably supporting said body, a plurality of disks having portions splined in aligned alternating relation respectively to the axle and the body, each disk characterized by being made from a carbon base material, a flexural strength of greater than 5,000 psi, said disk having a density greater than 1.40 grams per cc, and impact strength greater than 5 inch pounds per inch, an amount of carbon or graphite of at least about 75 percent of the total disk volume, and an average interlaminar spacing of crystalline and amorphous carbon of not more than 3.39 angstrom units at 15°C.
Claim 9
Dependent Claim
111 words
A low wear disk brake assembly comprising: a rotatable body, a fixed axle rotatably supporting said body, a plurality of disks having portions splined in aligned alternating relation respectively to the axle and the body, each disk characterized by being made from a carbon base material, a flexural strength of greater than 5,000 psi, said disk having a density greater than 1.40 grams per cc, and impact strength greater than 5 inch pounds per inch, an amount of carbon or graphite of at least about 75 percent of the total disk volume, and an average interlaminar spacing of crystalline and amorphous carbon of not more than 3.39 angstrom units at 15°C.
Claim 10
Dependent Claim
21 words
A low wear disk brake assembly according to claim 7 wherein said plurality of disks are located in the earth's atmosphere.
Claim 11
Dependent Claim
139 words
A process for producing low wear brake disks comprising the steps of: a. forming a disk blank of carbon based material, b. impregnating said blank with a hydrocarbon liquid or gas, c. heating said blank to a temperature of at least 2,500°C, so that a highly graphite blank is produced, d. repeating steps b and c a sufficient number of times to produce a blank having a flexural strength greater than 5,000 psi, said disk having a density greater than 1.40 grams per cc, and impact strength greater than 5 inch pounds per inch, an amount of carbon or graphite of at least about 75 percent of the total disk volume, a density greater than 1.40 grams per c.c. and wherein the average interlaminar spacing of crystalline and amorphous carbon is not more than 3.39 angstrom units at 15°C.
Claim 12
Dependent Claim
139 words
A process for producing low wear brake disks comprising the steps of: a. forming a disk blank of carbon based material, b. impregnating said blank with a hydrocarbon liquid or gas, c. heating said blank to a temperature of at least 2,500°C, so that a highly graphite blank is produced, d. repeating steps b and c a sufficient number of times to produce a blank having a flexural strength greater than 5,000 psi, said disk having a density greater than 1.40 grams per cc, and impact strength greater than 5 inch pounds per inch, an amount of carbon or graphite of at least about 75 percent of the total disk volume, a density greater than 1.40 grams per c.c. and wherein the average interlaminar spacing of crystalline and amorphous carbon is not more than 3.39 angstrom units at 15°C.
Claim 13
Dependent Claim
25 words
A process for producing low wear brake disks as in claim 9 wherein said interlaminar spacing ranges from about 3.35 to about 3.39 angstrom units.
References Cited (Backward Citations)
US3759353A
Cited
US3730320A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |