US3756010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic-induction clock
Assignee: Panasonic Electric Works Co Ltd
•
Filing: 1971-08-06
•
Granted: 1973-09-04
•
Expires: 1991-08-06
Abstract
Abstract In the clocks wherein the induction magnetic field of a commercial frequency is detected, and the detected signal is amplified, thereby driving the transistor motor, a magnetic induction type clock of which the transistor motor is driven in normal state by said detected signal but in abnormal state such as in the event of any fluctuation in the external field or power interruption, the transistor motor is driven by a signal supplied from a separately provided standard oscillation source.
Inventors
- 👤 A Kotani
- 👤 R Kimura
- 👤 M Kajihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:26
CPC Classifications
G; G04; G04C; G04C11/00; G04C11/08; G04C11/081; G04C11/084; G04C11/02; G04C3/00; G04C3/04; G04C3/06; G04C3/065; G04C3/067; G04R; G04R40/00; G04R40/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
223 words
A battery-driven cordless induction clock comprising a first synchronizing signal source including a signal detector unit having an induction coil for magnetically detecting the spatially leaking induction magnetic field of commercial frequency and producing an electrical output signal in response to the detected magnetic field, and an amplifier for amplifying the output signal of said detector unit, and a transistor motor unit operated by the output signal of said detector unit for driving the clock, a second synchronizing signal source including a standard oscillator producing an output signal at a standard frequency equal to the commercial frequency a synchronous coil for magnetically coupling the rotor of said transistor motor unit to said synchronizing signal sources, first switching means connected between said synchronous coil and said first synchronizing signal source, second switching means connected between said synchronous coil and said second synchronizing signal source, and actuating means responsive to the output signal from said first signal source for turning said first switching means on and said second switching means off to connect said synchronous coil only to said first signal source when said output signal indicates a normal magnetic field, and for turning said first switching means off and said second switching means on to connect said synchronous coil only to said second signal source when said output signal indicates an abnormal magnetic field.
Claim 2
Dependent Claim
223 words
A battery-driven cordless induction clock comprising a first synchronizing signal source including a signal detector unit having an induction coil for magnetically detecting the spatially leaking induction magnetic field of commercial frequency and producing an electrical output signal in response to the detected magnetic field, and an amplifier for amplifying the output signal of said detector unit, and a transistor motor unit operated by the output signal of said detector unit for driving the clock, a second synchronizing signal source including a standard oscillator producing an output signal at a standard frequency equal to the commercial frequency a synchronous coil for magnetically coupling the rotor of said transistor motor unit to said synchronizing signal sources, first switching means connected between said synchronous coil and said first synchronizing signal source, second switching means connected between said synchronous coil and said second synchronizing signal source, and actuating means responsive to the output signal from said first signal source for turning said first switching means on and said second switching means off to connect said synchronous coil only to said first signal source when said output signal indicates a normal magnetic field, and for turning said first switching means off and said second switching means on to connect said synchronous coil only to said second signal source when said output signal indicates an abnormal magnetic field.
Claim 3
Dependent Claim
63 words
A battery-driven cordless induction clock in accordance with claim 1, in which said actuating means comprises a circuit for differentiating the output signal from said amplifier, a monostable multivibrator operated by a trigger output from said differentiation circuit, an integrating circuit for integrating the output signal from said monostable multivibrator, and a Schmitt circuit operated by the output signal from said integrating circuit.
Claim 4
Dependent Claim
47 words
A battery-driven cordless induction clock in accordance with claim 1, in which said actuating means includes means for converting the output signal from said amplifier into direct current and means for detecting variations in said direct current to indicate whether said magnetic field is normal or abnormal.
Claim 5
Dependent Claim
87 words
A battery-driven cordless induction clock in accordance with claim 1, in which said amplifier comprises a voltage amplifier circuit, a clip circuit for clipping the output of said voltage amplifier circuit, an RC oscillator circuit to which the output of said voltage amplifier circuit is applied, a square wave shaper circuit connected to the output of said RC oscillator circuIt, a differentiation circuit for differentiating the output of said square wave shaper circuit, and a frequency divider circuit operated by the trigger output of said differentiation circuit.
Claim 6
Dependent Claim
38 words
A battery-driven cordless induction clock in accordance with claim 1, in which a filter circuit for passing only the signal of a frequency component close to the commercial frequency is disposed betweeen said induction coil and said amplifier.
Claim 7
Dependent Claim
63 words
A battery-driven cordless induction clock in accordance with claim 1, in which said transistor motor is of free-running type, said second synchronizing signal source is a balance wheel driver unit comprising a drive coil, a detection coil, transistor elements and balance wheels, and said synchronous coil magnetically coupled with the rotor of said transistor motor is disposed in the vicinity of said rotor.
Claim 8
Dependent Claim
54 words
A battery-driven cordless induction clock in accordance with claim 6, in which the axial direction of said induction coil, the axial direction of the balance wheel of said standard oscillation source, and the axial direction of the rotor of said transistor motor unit are disposed in parallel with each other on the same plane.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |