Patent US6577950B2 successfully refreshed from Google Patents.
Patent US4755072A successfully refreshed from Google Patents.
US4755072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removable, transparent, colored key caps for color coding a keyboard
Assignee: Individual
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Filing: 1986-10-15
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Granted: 1988-07-05
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Expires: 2006-10-15
Abstract
Abstract A flexible cup-shaped keyboard cap formed from transparent colored plastic enables a subset of keys to be distinguished by color while maintaining visibility of the key designation.
Inventors
- 👤 Andries P. Hoornweg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:28
CPC Classifications
B; B41; B41J; B41J5/00; B41J5/08; B41J5/12; G; G06; G06F; G06F3/00; G06F3/01; G06F3/02; G06F3/0202
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
110 words
A removable key cap comprising a single cup-shaped piece of transparent colored plastic having a top wall portion completely surrounded by an outwardly flared sidewall portion, said cap being suitable for fitting snugly over a keyboard key with said top wall portion contacting the top of the key and said sidewall portion extending part way down an outwardly flared side of the key so as to provide a frictional retentive force; said frictional retentive force being sufficient to retain the cap on the key in normal use while allowing removal as required; said top wall portion being without insignia but allowing any insignia of the underlying key to show through.
Claim 2
Dependent Claim
110 words
A removable key cap comprising a single cup-shaped piece of transparent colored plastic having a top wall portion completely surrounded by an outwardly flared sidewall portion, said cap being suitable for fitting snugly over a keyboard key with said top wall portion contacting the top of the key and said sidewall portion extending part way down an outwardly flared side of the key so as to provide a frictional retentive force; said frictional retentive force being sufficient to retain the cap on the key in normal use while allowing removal as required; said top wall portion being without insignia but allowing any insignia of the underlying key to show through.
Claim 3
Dependent Claim
25 words
The key cap of claim 1 in which the top wall portion is concave, whereby it can intimately contact the top of a concave key.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |