US3558853A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuser system for copying machine
Assignee: Xerox Corp
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Filing: 1969-05-14
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Granted: 1971-01-26
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Expires: 1989-05-14
Abstract
Abstract Fusing apparatus for heating developed images on copy sheets moving through an automatic copying machine at variable rates including a conveyor for transporting copy sheets having fusible images thereon at variable rates past a plurality of heater elements, a first circuit for generating ramp signals at a predetermined duration, and a second circuit including a thermistor responsive to changes in temperature and at least two voltage dividing networks each corresponding to a different fusing temperature. A zero cross pulse generator and comparator responsive to input signals from said first and second circuits emits signals when the output signals of said first circuit means exceeds that of said second means and a third circuit including at least one triac coupled to at least a portion of said heater elements receives signals from said zero cross pulse generator and comparator and applies power to said heater elements in accordance with a preselected copy travel rate.
Inventors
- 👤 Gary L Schluntz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:47
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
162 words
Fusing apparatus for fusing developed images on copy sheets moved through an automatic copying machine at variable rates comprising: means for transporting copy sheets having fusible developed images thereon at variable rates past a plurality of heater elements, first circuit means for generating ramp signals of a predetermined duration, second circuit means including a thermistor responsive to changes in temperature and at least two voltage dividing networks each corresponding to a different fusing rate to emit reference signals indicative of a proper fusing temperature, pulse generator and comparator means responsive to input signals from said first and second circuit means to emit signals when the output signals of said first circuit means exceeds that of said second means and third circuit means including at least one triac coupled to at least a portion of said heater elements to receive signals from said pulse generator and comparator means and apply power to said heater elements in accordance with a preselected copy travel rate.
Claim 2
Dependent Claim
162 words
Fusing apparatus for fusing developed images on copy sheets moved through an automatic copying machine at variable rates comprising: means for transporting copy sheets having fusible developed images thereon at variable rates past a plurality of heater elements, first circuit means for generating ramp signals of a predetermined duration, second circuit means including a thermistor responsive to changes in temperature and at least two voltage dividing networks each corresponding to a different fusing rate to emit reference signals indicative of a proper fusing temperature, pulse generator and comparator means responsive to input signals from said first and second circuit means to emit signals when the output signals of said first circuit means exceeds that of said second means and third circuit means including at least one triac coupled to at least a portion of said heater elements to receive signals from said pulse generator and comparator means and apply power to said heater elements in accordance with a preselected copy travel rate.
Claim 3
Dependent Claim
35 words
Apparatus according to claim 1 wherein said thermistor is positioned below the copy sheet travel path on a support member, and control means to move said support member toward and away from the travel path.
Claim 4
Dependent Claim
27 words
Apparatus according to claim 1 including circuit means for indicating a ready-print state to machine control when a proper temperature level of said heater elements is established.
Claim 5
Dependent Claim
23 words
Apparatus according to claim 4 including circuit means to override output signals from said second circuit means when an open thermistor condition exists.
Claim 6
Dependent Claim
29 words
Apparatus according to claim 1 wherein said first circuit means includes control means to effect different temperature levels for accommodating varying copy sheet stock and changes in ambient conditions.
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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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |