US4035612A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for detecting trouble in electric lines connecting relatively movable circuits
Assignee: Katsuragawa Electric Co Ltd
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Filing: 1975-06-27
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Granted: 1977-07-12
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Expires: 1995-06-27
Abstract
Abstract A circuit for detecting trouble in a sliding contact mechanism comprising a fixed contact portion and a movable contact portion, said fixed portion being connected to an electric power source. A radio-frequency signal is generated when insufficient electrical connection is caused in the sliding contact mechanism by, for example, depositing dusts thereon, said signal being delivered to a suitable alarm device to indicate the troublesome state.
Inventors
- 👤 Tutomu Ishiguro
- 👤 Yukio Katano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:55
CPC Classifications
H; H02; H02H; H02H1/00; H02H1/0007; H02H1/003; G; G01; G01R; G01R31/00; G01R31/50; G01R31/52; G01R31/54; G01R31/58; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; H02H5/00; H02H5/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
96 words
A circuit for controlling the temperature of a heating roller in an electrophotographic copying machine comprising a temperature detecting element fixed to the heating roller, a sliding contact electrically connecting said temperature detecting element to a stationary circuit, a high frequency oscillator having its output connected to said sliding contact, a capacitor in circuit with said sliding contact for passing the output signal of said oscillator to ground through said sliding contact, and a signal generator connected to the output of said high frequency oscillator for producing a signal indicating imperfect operation of said sliding contact.
Claim 2
Dependent Claim
96 words
A circuit for controlling the temperature of a heating roller in an electrophotographic copying machine comprising a temperature detecting element fixed to the heating roller, a sliding contact electrically connecting said temperature detecting element to a stationary circuit, a high frequency oscillator having its output connected to said sliding contact, a capacitor in circuit with said sliding contact for passing the output signal of said oscillator to ground through said sliding contact, and a signal generator connected to the output of said high frequency oscillator for producing a signal indicating imperfect operation of said sliding contact.
Claim 3
Dependent Claim
48 words
A control circuit according to claim 1, further comprising a comparator circuit for comparing an output signal of the temperature detecting element with a reference signal, and a controller for regulating the current flowing through the heating roller in response to the output signal of the comparator circuit.
Claim 4
Dependent Claim
32 words
A control circuit according to claim 1, further comprising a capacitor connected across the temperature detecting element to provide a branch circuit for the high frequency signal from the high frequency oscillator.
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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |