Patent US4374795A successfully refreshed from Google Patents.
US4374795A
Expired / Lapsed
US
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Production of mold charge of elastomeric material containing magnetic oxide filler
Assignee: AT&T Inc
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Filing: 1980-09-11
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Granted: 1983-02-22
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Expires: 2000-09-11
Abstract
Abstract A method for preforming magnetic drum material involves the use of a hydraulic press and sleeve which in turn compresses the material and then cuts the material into a specific shape. This process is repeated until the material builds up in the sleeve to the required charge thickness. This method has improved the molding process by eliminating air and gas voids in the molded magnetic drum.
Inventors
- 👤 John P. Keilp
- 👤 Warren F. Moore
- 👤 Victor Sirbu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:29
CPC Classifications
B; B29; B29B; B29B11/00; B29B11/04; B26; B26F; B26F1/00; B26F1/38; B26F1/40; B29B11/02; G; G11; G11B; G11B5/00; G11B5/84; Y; Y10; Y10S; Y10S264/00; Y10S264/58; Y10S264/67; Y10S425/00; Y10S425/812; Y10T; Y10T83/00; Y10T83/04; Y10T83/0405; Y10T83/0419; Y10T83/0429; Y10T83/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
96 words
A method of producing a mold charge from an elastomeric molding material comprising the steps of: (1) applying a compression force to a piece of said material to flatten said material and drive out entrapped air and gas therefrom, (2) applying a shearing force to said material to shape said material into the desired cross-sectional outline, (3) drawing another piece of said material under said prior piece and repeating steps (1) and (2), and (4) building up said material by repeating steps (1) through (3) until the desired air- and gas-free mold charge thickness is obtained.
Claim 2
Independent Claim
96 words
A method of producing a mold charge from an elastomeric molding material comprising the steps of: (1) applying a compression force to a piece of said material to flatten said material and drive out entrapped air and gas therefrom, (2) applying a shearing force to said material to shape said material into the desired cross-sectional outline, (3) drawing another piece of said material under said prior piece and repeating steps (1) and (2), and (4) building up said material by repeating steps (1) through (3) until the desired air- and gas-free mold charge thickness is obtained.
Claim 3
Dependent Claim
19 words
The method of claim 1 in which step (2) cuts said material into a disk of circular cross section.
Claim 4
Dependent Claim
19 words
The method of claim 1 in which step (2) cuts said material into an annulus of toroidal cross section.
Claim 5
Dependent Claim
14 words
The method of claim 1 in which said elastomeric molding material contains magnetic oxide.
References Cited (Backward Citations)
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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) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |