US4393967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic clutch
Assignee: International Business Machines Corp
•
Filing: 1981-10-21
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Granted: 1983-07-19
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Expires: 2001-10-21
Abstract
Abstract An electrostatic clutch operable by the Johnsen-Rahbek effect, which may be used to operate, e.g., a print hammer device, is described, said clutch comprising a rotatable drum and a band engagable therewith, wherein the engagable surface of the drum is a semiconductive surface prepared by sputtering or vapor depositing a layer of substantially pure silicon carbide onto a conductive substrate.
Inventors
- 👤 Jerome J. Cuomo
- 👤 Alfred J. Landon
- 👤 Han C. Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:30
CPC Classifications
H; H02; H02N; H02N13/00; B; B41; B41J; B41J9/00; B41J9/26; B41J9/40
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
81 words
An electrostatic clutch operable by the Johnsen-Rahbek effect, comprising: a rotatable drum and a band engageable therewith, said drum including an engageable surface which is a semiconductive surface comprising a layer of substantially pure silicon carbide on a conductive substrate, said layer having a thickness between about 10 μm and 2,500 μm and containing a dopant in an amount effective to cause the resistivity of the layer to be within a range of from about 10 5 to 10 7 ohm-cm.
Claim 2
Dependent Claim
81 words
An electrostatic clutch operable by the Johnsen-Rahbek effect, comprising: a rotatable drum and a band engageable therewith, said drum including an engageable surface which is a semiconductive surface comprising a layer of substantially pure silicon carbide on a conductive substrate, said layer having a thickness between about 10 μm and 2,500 μm and containing a dopant in an amount effective to cause the resistivity of the layer to be within a range of from about 10 5 to 10 7 ohm-cm.
Claim 3
Dependent Claim
21 words
An electrostatic clutch as claimed in claim 1, wherein said layer of silicon carbide is an amorphous layer prepared by sputtering.
Claim 4
Dependent Claim
22 words
An electrostatic clutch as claimed in claim 1, wherein said layer of silicon carbide is a crystalline layer prepared by vapor deposition.
Claim 5
Dependent Claim
23 words
An electrostatic clutch as claimed in claim 1, wherein said layer of silicon carbide has a thickness between 10 μm and 1,500 μm.
Claim 6
Dependent Claim
24 words
An electrostatic clutch as claimed in claim 1, wherein said layer of silicon carbide has a thickness of between 100 μm and 500 μm.
Claim 7
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is boron.
Claim 8
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is aluminum.
Claim 9
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is gallium.
Claim 10
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is indium.
Claim 11
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is thallium.
Claim 12
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is nitrogen.
Claim 13
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is phosphorous.
Claim 14
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is arsenic.
Claim 15
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is antimony.
Claim 16
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is bismuth.
Claim 17
Dependent Claim
13 words
An electrostatic clutch as claimed in claim 1, wherein said dopant is hydrogen.
Claim 18
Dependent Claim
16 words
An electrostatic clutch as claimed in claim 1, wherein said band is formed of stainless steel.
Claim 19
Dependent Claim
17 words
An electrostatic clutch as claimed in claim 1, wherein said band is formed of a tungsten alloy.
Claim 20
Dependent Claim
14 words
An electrostatic clutch as claimed in claim 1, wherein said conductive substrate is carbon.
Claim 21
Dependent Claim
14 words
An electrostatic clutch as claimed in claim 1, wherein said conductive substrate is silicon.
Claim 22
Dependent Claim
14 words
An electrostatic clutch as claimed in claim 1, wherein said conductive substrate is molybdenum.
Claim 23
Dependent Claim
15 words
An electrostatic clutch as claimed in claim 1, wherein said conductive substrate is stainless steel.
Claim 24
Dependent Claim
16 words
An electrostatic clutch as claimed in claim 1, wherein said conductive substrate is a titanium alloy.
Claim 25
Dependent Claim
16 words
An electrostatic clutch as claimed in claim 1, wherein said conductive substrate is an aluminum alloy.
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) | 1986-07-18 | 1987-01-17 | 1987-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-18 | 1991-01-17 | 1991-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-18 | 1995-01-17 | 1995-07-19 | $7700.00 | Window Closed / Lapsed |