Patent US4170926A successfully refreshed from Google Patents.
US4170926A
Expired / Lapsed
US
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Fluted core disc brake piston
Assignee: Occidental Chemical Corp
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Filing: 1978-01-20
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Granted: 1979-10-16
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Expires: 1998-01-20
Abstract
Abstract A plastic disc brake piston is disclosed with a novel fluted inner core design, giving a piston with superior structural strength, crack resistance, and improved heat dissipation when used in disc brake assemblies.
Inventors
- 👤 John E. Emmett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:24
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/14; F05; F05C; F05C2251/00; F05C2251/04; F05C2251/042; F16D2125/00; F16D2125/02; F16D2125/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
78 words
In a disc brake caliper assembly comprising a disc brake cylinder housing and a plastic disc brake piston having a cylindrical outer surface and a hollow inner core having an open end and a closed end defining a substantially planar surface, the improvement wherein the piston has a fluted inner core surface extending from said open end to said substantially planar surface which has a cross-section circumference substantially equal to the cross-section circumference of said cylindrical outer surface.
Claim 2
Dependent Claim
78 words
In a disc brake caliper assembly comprising a disc brake cylinder housing and a plastic disc brake piston having a cylindrical outer surface and a hollow inner core having an open end and a closed end defining a substantially planar surface, the improvement wherein the piston has a fluted inner core surface extending from said open end to said substantially planar surface which has a cross-section circumference substantially equal to the cross-section circumference of said cylindrical outer surface.
Claim 3
Dependent Claim
17 words
The assembly of claim 1 wherein the flutings of said fluted inner core surface are equally spaced.
Claim 4
Dependent Claim
16 words
The assembly of claim 1 wherein the flutings of said fluted inner core surface are rounded.
Claim 5
Dependent Claim
16 words
The assembly of claim 1 wherein the flutings of said fluted inner core surface are square.
Claim 6
Dependent Claim
16 words
The assembly of claim 1 wherein the flutings of said fluted inner core surface are oval.
Claim 7
Dependent Claim
11 words
The assembly of claim 3 wherein said flutings are equally spaced.
Claim 8
Dependent Claim
12 words
The assembly of claim 1 wherein said plastic comprises a phenol-aldehyde resin.
Claim 9
Dependent Claim
12 words
The assembly of claim 7 wherein said resin is a phenol-formaldehyde resin.
Claim 10
Dependent Claim
12 words
The assembly of claim 1 wherein said plastic contains a filler substance.
Claim 11
Dependent Claim
27 words
The assembly of claim 9 wherein said filler substance is selected from the group consisting of glass, metal, natural mineral fillers, synthetic mineral fillers, and mixtures thereof.
References Cited (Backward Citations)
US2307671A
Cited
US2752755A
Cited
US3040712A
Cited
US3091502A
Cited
US3212411A
Cited
US3497038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-15 | 1983-04-16 | 1983-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-15 | 1987-04-16 | 1987-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-15 | 1991-04-16 | 1991-10-16 | $7700.00 | Window Closed / Lapsed |