US3889786A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake drum cooling structure
Assignee: Boeing North American Inc
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Filing: 1973-06-28
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Granted: 1975-06-17
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Expires: 1993-06-28
Abstract
Abstract A method of manufacturing a brake drum having a plurality of axially spaced, circumferentially extending ribs provided on the exterior surface thereof. The method includes casting molten grey iron into a mold cavity formed by a plurality of axially split external mold segments spaced radially outward from an internal mold member, spacing the radially inward portions of the interfacing lateral edge surfaces of the external mold segments to form a flash base free of white iron metal at the parting line between adjacent external mold segments and, after cooling the molten iron and removing the mold members, grinding away at least a portion of the flash metal formed between the interfacing lateral edge surfaces of the external mold segments radially outward of the flash base to provide an axially extending ridge free of white iron and traversing the axially spaced ribs. The brake drum has a plurality of radially extending, heat radiating projections formed on the exterior surface thereof including a plurality of circumferentially spaced sets of helical fins with each successive set of helical fins being disposed at a helical orientation opposite to the helical orientation of the preceding set of helical fins to induce a flow of cooling air over the external surface of the brake drum regardless of the direction of rotation of the brake drum.
Inventors
- 👤 Carl N Schrader
- 👤 Frank H Fisher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:39
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/02; F16D65/10; F16D65/78; F16D65/82; F16D65/827; F16D2065/13; F16D2065/1304; F16D2065/1332; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4998; Y10T29/49988
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
156 words
A metal brake drum comprising a cast generally cylindrical main body portion open at one axial end thereof and provided with means for mounting the drum to a wheel assembly at the other end, the interior of said main body portion comprising a cylindrical friction braking surface, the exterior of said main body portion having a plurality of radially extending heat radiating projections integrally cast and formed from the same metal as said main body portion adjacent the open end thereof, said radially extending projections comprising a plurality of circumferentially spaced sets of helical fins with each successive set of helical fins comprising a plurality of helically oriented radial projections disposed at a helical orientation opposite to the helical orientation of the projections comprising the preceding set and a plurality of circumferentially spaced groups of axially or circumferentially extending ribs with each set of helical fins separating a pair of circumferentially spaced groups of said ribs.
Claim 2
Dependent Claim
156 words
A metal brake drum comprising a cast generally cylindrical main body portion open at one axial end thereof and provided with means for mounting the drum to a wheel assembly at the other end, the interior of said main body portion comprising a cylindrical friction braking surface, the exterior of said main body portion having a plurality of radially extending heat radiating projections integrally cast and formed from the same metal as said main body portion adjacent the open end thereof, said radially extending projections comprising a plurality of circumferentially spaced sets of helical fins with each successive set of helical fins comprising a plurality of helically oriented radial projections disposed at a helical orientation opposite to the helical orientation of the projections comprising the preceding set and a plurality of circumferentially spaced groups of axially or circumferentially extending ribs with each set of helical fins separating a pair of circumferentially spaced groups of said ribs.
Claim 3
Dependent Claim
85 words
The brake drum of claim 1 wherein said exterior of said main body portion is provided with two diametrically opposed sets of helical fins, one of said sets of helical fins being comprised of a plurality of circumferentially spaced helical fins having a righthand helical orientation and the other set of helical fins being comprised of a plurality of circumferentially spaced helical fins having a lefthand helical orientation, and said sets Of helical fins are separated by two groups of axially spaced circumferentially extending ribs.
Claim 4
Dependent Claim
225 words
A metal brake drum comprising a cast generally cylindrical main body portion open at one axial end, the opposite end thereof being partially closed by a radially extending flange for rotatably mounting said brake drum to an axle of a wheel assembly, said flange and said main body portion being joined by an integrally formed conical section of gradually decreasing diameter, the interior surface of said main body portion comprising a cylindrical friction braking surface, the exterior of said main body portion having integrally cast and formed from the same metal as said main body portion adjacent the open end thereof a plurality of axially spaced circumferentially extending ribs and a plurality of helical fins, said axially spaced, circumferentially extending ribs being formed as two diametrically opposed groups circumferentially separated by two sets of helical fins, each of said sets of helical fins being comprised of a plurality of circumferentially spaced helical fins with the helix angle of one set of helical fins being oppositely disposed with respect to the helix angle of the other set of helical fins to thereby orient one of said sets of helical fins in a direction which will induce a flow of air across the exterior of said main body portion from said open end toward said conical section regardless of the direction of rotation of said brake drum.
Claim 5
Dependent Claim
225 words
A metal brake drum comprising a cast generally cylindrical main body portion open at one axial end, the opposite end thereof being partially closed by a radially extending flange for rotatably mounting said brake drum to an axle of a wheel assembly, said flange and said main body portion being joined by an integrally formed conical section of gradually decreasing diameter, the interior surface of said main body portion comprising a cylindrical friction braking surface, the exterior of said main body portion having integrally cast and formed from the same metal as said main body portion adjacent the open end thereof a plurality of axially spaced circumferentially extending ribs and a plurality of helical fins, said axially spaced, circumferentially extending ribs being formed as two diametrically opposed groups circumferentially separated by two sets of helical fins, each of said sets of helical fins being comprised of a plurality of circumferentially spaced helical fins with the helix angle of one set of helical fins being oppositely disposed with respect to the helix angle of the other set of helical fins to thereby orient one of said sets of helical fins in a direction which will induce a flow of air across the exterior of said main body portion from said open end toward said conical section regardless of the direction of rotation of said brake drum.
Claim 6
Dependent Claim
41 words
The brake drum of claim 3 wherein said helical fins and adjacent ones of said axially spaced, circumferentially extending ribs gradually decrease in radial height as they progress in an axial direction away from said open end of said brake drum.
Claim 7
Dependent Claim
41 words
The brake drum of claim 4 wherein said helical fins and said axially spaced, circumferentially extending ribs extend axially away from said open end of said brake drum for an axial distance less than the axial length of said braking surface.
References Cited (Backward Citations)
US1865311A
Cited
US2059170A
Cited
US2091602A
Cited
US2563769A
Cited
US2633944A
Cited
US3003598A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |