Patent US4419704A successfully refreshed from Google Patents.
US4419704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bernoulli plate for stabilization of flexible magnetic disk
Assignee: EMC Corp
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Filing: 1981-04-24
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Granted: 1983-12-06
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Expires: 2001-04-24
Abstract
Abstract An improved Bernoulli plate for juxtaposition to a rotating flexible magnetic disk so that the disk is rendered substantially rigid by a vacuum formed by the air between the plate and the disk being urged outwardly under the influence of centrifugal force is disclosed. The plate is formed by coining a metal substrate and thereafter electroplating the coined substrate so that any sharp irregularities resulting from the coining operation are smoothed, while the surface is provided with a hard, wear-resistant coating.
Inventors
- 👤 Anton J. Radman
- 👤 Randall C. Bauck
- 👤 Peter S. Kleczkowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:32
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
93 words
Method of manufacturing a Bernoulli plate for juxtaposition to a rotating magnetic disk so that said disk is stabilized, said method comprising the steps of: providing a substantially flat, virgin plate consisting of a first relatively soft metal; coining said plate at numerous locations with a sharply-pointed tool to form annular uplifted portions surrounding pits in said surface in a coining operation; and coating said coined plate with a layer of a second, relatively harder metal, whereby sharp edges, burrs and the like in said plate formed in said coining operation are smoothed.
Claim 2
Dependent Claim
93 words
Method of manufacturing a Bernoulli plate for juxtaposition to a rotating magnetic disk so that said disk is stabilized, said method comprising the steps of: providing a substantially flat, virgin plate consisting of a first relatively soft metal; coining said plate at numerous locations with a sharply-pointed tool to form annular uplifted portions surrounding pits in said surface in a coining operation; and coating said coined plate with a layer of a second, relatively harder metal, whereby sharp edges, burrs and the like in said plate formed in said coining operation are smoothed.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said first relatively soft material is selected from the group consisting of aluminum and steel.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein said second relatively harder metal is selected from the group consisting of chromium and its alloys.
Claim 5
Dependent Claim
84 words
A magnetic disk drive comprising a motor for rotating a flexible magnetic disk, a Bernoulli plate and a read/write head, said Bernoulli plate comprising: a substrate of a first relatively soft metal having been coined at pluralities of locations so as to comprise pits having generally annular upraised portions therearound in said surface and a coating of a second relatively harder material, whereby burrs and sharp edges of said pits and upraised portions are smoothed and a wear-resistant surface is provided to said plate.
Claim 6
Dependent Claim
84 words
A magnetic disk drive comprising a motor for rotating a flexible magnetic disk, a Bernoulli plate and a read/write head, said Bernoulli plate comprising: a substrate of a first relatively soft metal having been coined at pluralities of locations so as to comprise pits having generally annular upraised portions therearound in said surface and a coating of a second relatively harder material, whereby burrs and sharp edges of said pits and upraised portions are smoothed and a wear-resistant surface is provided to said plate.
Claim 7
Dependent Claim
37 words
The apparatus of claim 1 wherein said substrate is formed of a metal selected from the group consisting of aluminum and steel and said coating material is selected from the group consisting of chromium and its alloys.
Claim 8
Dependent Claim
73 words
A Bernoulli plate for stabilization of a flexible disk rotated in juxtaposition thereto, comprising a substrate of a first relatively soft metal having been coined at pluralities of locations in order to comprise depressions surrounded by uplifted portions of said substrate in said surface and a coating of a second relatively harder material, whereby burrs and sharp edges of said uplifted portions are smoothed and a wear-resistant surface is provided to said plate.
Claim 9
Dependent Claim
73 words
A Bernoulli plate for stabilization of a flexible disk rotated in juxtaposition thereto, comprising a substrate of a first relatively soft metal having been coined at pluralities of locations in order to comprise depressions surrounded by uplifted portions of said substrate in said surface and a coating of a second relatively harder material, whereby burrs and sharp edges of said uplifted portions are smoothed and a wear-resistant surface is provided to said plate.
Claim 10
Dependent Claim
22 words
The plate of claim 6 wherein said substrate is formed of a metal selected from the group consisting of aluminum and steel.
Claim 11
Dependent Claim
22 words
The plate of claim 6 wherein said coating is of a material selected from the group consisting of chromium and its alloys.
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) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |