US3621945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disc brakes
Assignee: Unifrax I LLC
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Filing: 1969-11-12
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Granted: 1971-11-23
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Expires: 1989-11-12
Abstract
Abstract Friction discs for use in multiple disc brakes, e.g., carbon friction discs for use in aircraft brakes, are provided with scalloped perimeters for coaction with driving or restraining elements having similar scalloped perimeters. Both sets of scallops have substantially flat contact surfaces disposed at an angle which optimizes the distribution of force on the friction disc. The friction disc scallops interfit between and engage the coacting element scallops, but are capable of limited expansion and rotary movement between the coacting element scallops.
Inventors
- 👤 William J Spry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:39
CPC Classifications
F; F16; F16D; F16D55/00; F16D55/24; F16D55/26; F16D55/36; F16D2055/0004; F16D2055/0058; F16D65/00; F16D65/02; F16D2065/13; F16D2065/134; F16D2065/1356; F16D2065/1368; Y; Y10; Y10T; Y10T403/00; Y10T403/70; Y10T403/7026; Y10T403/7035
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
224 words
In combination in a disc brake, a friction disc consisting essentially of carbon and a coaxially aligned coacting element, (1) the friction disc having an inner perimeter and an outer perimeter, one perimeter having formed therein a plurality of equally spaced scallops, each scallop having a substantially flat contact surface disposed at an angle with respect to the radius of the friction disc passing through the center of the contact surface of the friction disc, such angle of each contact surface being substantially equal to each other such angle, and having a cotangent which approximates the ratio of the strengths which bear stress within said disc and (2) the coacting element having a perimeter for engagement with the scalloped perimeter of the friction disc, said coacting element perimeter having formed therein a plurality of equally spaced scallops, equal in number to the friction disc scallops, each coacting element scallop having a substantially flat contact surface disposed at substantially the same angle with respect to the radius of the friction disc passing through the center of the contact surface as the angle of the corresponding contact surface of the friction disc; the friction disc scallops interfitting between the coacting element scallops and being capable of limited expansion and rotary movement therebetween; a loose working fit being provided between the friction disc and its coacting element.
Claim 2
Dependent Claim
224 words
In combination in a disc brake, a friction disc consisting essentially of carbon and a coaxially aligned coacting element, (1) the friction disc having an inner perimeter and an outer perimeter, one perimeter having formed therein a plurality of equally spaced scallops, each scallop having a substantially flat contact surface disposed at an angle with respect to the radius of the friction disc passing through the center of the contact surface of the friction disc, such angle of each contact surface being substantially equal to each other such angle, and having a cotangent which approximates the ratio of the strengths which bear stress within said disc and (2) the coacting element having a perimeter for engagement with the scalloped perimeter of the friction disc, said coacting element perimeter having formed therein a plurality of equally spaced scallops, equal in number to the friction disc scallops, each coacting element scallop having a substantially flat contact surface disposed at substantially the same angle with respect to the radius of the friction disc passing through the center of the contact surface as the angle of the corresponding contact surface of the friction disc; the friction disc scallops interfitting between the coacting element scallops and being capable of limited expansion and rotary movement therebetween; a loose working fit being provided between the friction disc and its coacting element.
Claim 3
Dependent Claim
204 words
In combination in a disc brake, (1) a plurality of internally scalloped friction discs; consisting essentially of carbon, said scallops being equally spaced and each having a substantially flat contact surface disposed at an angle with respect to the radius of the disc whose cotangent approximates the ratio of the shear strength of the carbon to the tensile strength of the carbon; (2) an externally scalloped element, coaxially aligned with and coacting with the internally scalloped friction discs; (3) a plurality of externally scalloped friction discs, consisting essentially of carbon, said scallops being equally spaced and each having a substantially flat contact surface disposed at an angle with respect to the radius of the disc whose cotangent approximates the ratio of the shear strength of the carbon to the compressive strength of the carbon, coaxially aligned with and alternately spaced between the internally scalloped friction discs; (4) an internally scalloped element coaxially aligned with and coacting with the externally scalloped friction discs; and (5) means for urging the friction discs into mutual contact, whereby to arrest rotary motion of one coacting element with respect to the other coacting element; a loose working fit being provided between each scalloped friction disc and its coacting element.
Claim 4
Dependent Claim
204 words
In combination in a disc brake, (1) a plurality of internally scalloped friction discs; consisting essentially of carbon, said scallops being equally spaced and each having a substantially flat contact surface disposed at an angle with respect to the radius of the disc whose cotangent approximates the ratio of the shear strength of the carbon to the tensile strength of the carbon; (2) an externally scalloped element, coaxially aligned with and coacting with the internally scalloped friction discs; (3) a plurality of externally scalloped friction discs, consisting essentially of carbon, said scallops being equally spaced and each having a substantially flat contact surface disposed at an angle with respect to the radius of the disc whose cotangent approximates the ratio of the shear strength of the carbon to the compressive strength of the carbon, coaxially aligned with and alternately spaced between the internally scalloped friction discs; (4) an internally scalloped element coaxially aligned with and coacting with the externally scalloped friction discs; and (5) means for urging the friction discs into mutual contact, whereby to arrest rotary motion of one coacting element with respect to the other coacting element; a loose working fit being provided between each scalloped friction disc and its coacting element.
Claim 5
Dependent Claim
99 words
A friction disc for use in a disc brake, the disc consisting essentially of carbon and having an inner perimeter and an outer perimeter, one perimeter having formed therein a plurality of equally spaced scallops, each scallop having a substantially flat contact surface disposed at an angle with respect to the radius of the friction disc passing through the center of the contact surface of the friction disc, such angle of each contact surface being substantially equal to each other such angle, and having a cotangent which approximates the ratio of the strengths which bear stress within said disc.
Claim 6
Dependent Claim
99 words
A friction disc for use in a disc brake, the disc consisting essentially of carbon and having an inner perimeter and an outer perimeter, one perimeter having formed therein a plurality of equally spaced scallops, each scallop having a substantially flat contact surface disposed at an angle with respect to the radius of the friction disc passing through the center of the contact surface of the friction disc, such angle of each contact surface being substantially equal to each other such angle, and having a cotangent which approximates the ratio of the strengths which bear stress within said disc.
Claim 7
Dependent Claim
36 words
The friction disc of claim 3, wherein the scalloped perimeter is the outer perimeter of the friction disc, said angle having a cotangent which approximates the ratio of the shear and compressive strengths of said disc.
Claim 8
Dependent Claim
36 words
The friction disc of claim 3, wherein the scalloped perimeter is the inner perimeter of the friction disc, said angle having a cotangent which approximates the ratio of the shear and tensile strengths of said disc.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |