Patent EP0112601A1 successfully refreshed from Google Patents.
US4456859A
Expired / Lapsed
US
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Sewing machine drive motor control system
Assignee: Janome Corp
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Filing: 1981-11-30
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Granted: 1984-06-26
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Expires: 2001-11-30
Abstract
Abstract A speed-control circuit for a motor of the sewing machine is disclosed. The circuit includes a controller, thyristors for controlling the rotation of the motor in dependence upon the operation of the controller, operational amplifiers activated in dependence upon the operation of the controller to produce a speed designating voltage, a frequency - voltage converter which receives a frequency representing the speed of rotation of the main shaft of the sewing machine, a comparator for comparing that speed designating voltage with the voltage of the frequency-voltage converter to detect a motor drive phase, and a light emitting diode and a phototransistor activated by the motor drive phase and operative for controlling the ignition phase of those thyristors.
Inventors
- 👤 Kazuo Watanabe
- 👤 Hachiro Makabe
- 👤 Akira Orii
- 👤 Michio Hisatake
- 👤 Kazuji Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:26
CPC Classifications
D; D05; D05B; D05B69/00; D05B69/22; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/902; Y10S388/907; Y10S388/908; Y10S388/917; Y10S388/923; Y10S388/933
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
187 words
A speed control circuit of a motor used in combination with a sewing machine having a main drive shaft rotated by the motor to operate the stitch forming device of the sewing machine, said speed control circuit including a controller, thyristors (10) for controlling the rotation of the motor in dependence upon the operation of the controller, said speed control circuit further comprising means (OP 1 ) for producing a constant triangular wave voltage, means (C 2 , OP 2 ) responsive to operation of the controller to change the constant triangular wave voltage into a variable speed-designating voltage (J) in a period of an AC power source, a frequency-voltage converter receiving a frequency representing the rotation speed of the main drive shaft of the sewing machine so as to produce the corresponding voltage (F), a comparator comparing the variable speed-designating voltage (J) and the voltage of said frequency-voltage converter to detect a motor drive phase (C) of the speed-designating voltage (J), and control means (LED 1 , PTr 1 ) activated by the motor drive phase of the speed-designating voltage (J) to ignite the thyristors (10).
Claim 2
Dependent Claim
187 words
A speed control circuit of a motor used in combination with a sewing machine having a main drive shaft rotated by the motor to operate the stitch forming device of the sewing machine, said speed control circuit including a controller, thyristors (10) for controlling the rotation of the motor in dependence upon the operation of the controller, said speed control circuit further comprising means (OP 1 ) for producing a constant triangular wave voltage, means (C 2 , OP 2 ) responsive to operation of the controller to change the constant triangular wave voltage into a variable speed-designating voltage (J) in a period of an AC power source, a frequency-voltage converter receiving a frequency representing the rotation speed of the main drive shaft of the sewing machine so as to produce the corresponding voltage (F), a comparator comparing the variable speed-designating voltage (J) and the voltage of said frequency-voltage converter to detect a motor drive phase (C) of the speed-designating voltage (J), and control means (LED 1 , PTr 1 ) activated by the motor drive phase of the speed-designating voltage (J) to ignite the thyristors (10).
Claim 3
Dependent Claim
75 words
The circuit as defined in claim 1, wherein said means to produce a constant triangular wave voltage include a first operational amplifier (OP 1 ) receiving an AC power source voltage and said means to change the constant triangular wave into a variable speed-designating voltage include a second operational amplifier (OP 2 ) and a capacitor (C 2 ), said second operational amplifier being operative to accelerate the charge of the capacitor (C 2 ).
Claim 4
Dependent Claim
37 words
The circuit as defined in claim 2, wherein said frequency-voltage converter includes a phototransistor (PTr 2 ), the sewing machine being provided with a screen disc connected to the main shaft and adapted to actuate said phototransistor.
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) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |