US4346334A
Expired / Lapsed
US
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DC Servomotor system
Assignee: Brother Industries Ltd
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Filing: 1981-07-20
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Granted: 1982-08-24
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Expires: 2001-07-20
Abstract
Abstract An automatic motion or position control DC servomotor system in which a load-driving axis driven by a DC motor to be controlled in one rotary mechanism is rotated synchronously with, or following the rotation of, a reference axis manually operated or driven by another DC motor. The system comprises a position signal generator producing first sine- and cosine-wave signals corresponding to an angle of rotation of the controlled load-driving axis; a command signal generator producing second sine- and cosine-wave signals corresponding to an angle of rotation of the reference axis; an arithmetic unit processing the first and second sine- and cosine-wave signals and providing a sine-wave feedback voltage output signal; and a driver circuit amplifying the feedback voltage signal and providing a thus amplified signal to the DC motor driving the load-driving axis. When the reference axis is driven by another DC motor, the command signal generator may be a second position signal generator. The command signal and position signal generators each consists of a combination which preferably comprises a sine-cosine potentiometer. The DC servomotor system is suitably applicable to a sewing machine in such manner that the rotating hook shaft is driven by a first DC motor and the arm shaft by a second DC motor, the first DC motor being controlled synchronously with the second one under closed-loop feedback control as stated above.
Inventors
- 👤 Toyokazu Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:17
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/121; D; D05; D05B; D05B69/00; D05B69/10; D05B69/12; D05B69/14; D05B69/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
172 words
A DC servomotor system comprising: (a) a direct current motor; (b) first signal generating means for producing, in response to rotary movement of said direct current motor, a first sine-wave signal A·SIN x and a first cosine-wave signal B·COS x, where x is an angle of rotation of said direct current motor, and A and B are constants; (c) second signal generating means for producing a second sine-wave signal C·SIN y and a second cosine-wave signal D·COS y, where y is a variable and C and D are constants; (d) arithmetic means for processing said first sine- and cosine-wave signals A·SIN x and B·COS x and said second sine- and cosine-wave signals C·SIN y and D·COS y to produce a sine-wave signal E·SIN (y-x), where E is a constant; and (e) means for amplifying said sine-wave signal E·SIN (y-x) and providing a thus amplified sine-wave signal E·SIN (y-x) to said direct current motor, whereby said direct current motor is rotated in accordance with the signals produced from said second signal generating means.
Claim 2
Dependent Claim
172 words
A DC servomotor system comprising: (a) a direct current motor; (b) first signal generating means for producing, in response to rotary movement of said direct current motor, a first sine-wave signal A·SIN x and a first cosine-wave signal B·COS x, where x is an angle of rotation of said direct current motor, and A and B are constants; (c) second signal generating means for producing a second sine-wave signal C·SIN y and a second cosine-wave signal D·COS y, where y is a variable and C and D are constants; (d) arithmetic means for processing said first sine- and cosine-wave signals A·SIN x and B·COS x and said second sine- and cosine-wave signals C·SIN y and D·COS y to produce a sine-wave signal E·SIN (y-x), where E is a constant; and (e) means for amplifying said sine-wave signal E·SIN (y-x) and providing a thus amplified sine-wave signal E·SIN (y-x) to said direct current motor, whereby said direct current motor is rotated in accordance with the signals produced from said second signal generating means.
Claim 3
Dependent Claim
232 words
A DC servomotor system comprising: (a) a direct current motor; (b) a position signal generating unit connected to said direct current motor for producing, in response to rotary movement of said direct current motor, a first sine-wave signal A·SIN x and a first cosine-wave signal B·COS x, where x is an angle of rotation of said direct current motor as measured from a reference angular position thereof, and A and B are constants; (c) a command signal generating unit which produces a second sine-wave signal C·SIN y and a second cosine-wave signal D·COS y, where y is an angle of rotation of said command signal generating unit as measured from a reference angular position thereof, and C and D are constants; (d) an arithmetic circuit connected to said position signal generating unit and said command signal generating unit for receiving, as inputs thereto, said first sine- and cosine-wave signals A·SIN x and B·COS x and said second sine- and cosine-wave signals C·SIN y and D·COS y and producing, as an output therefrom, a sine-wave signal E·SIN (y-x), where E is a constant; and (e) a driver circuit connected to said arithmetic circuit for amplifying said sine-wave signal E·SIN (y-x) and providing a thus amplified sine-wave signal E·SIN (y-x) to said direct current motor, whereby said direct current motor is rotated in accordance with the signals produced from said command signal generating unit.
Claim 4
Dependent Claim
232 words
A DC servomotor system comprising: (a) a direct current motor; (b) a position signal generating unit connected to said direct current motor for producing, in response to rotary movement of said direct current motor, a first sine-wave signal A·SIN x and a first cosine-wave signal B·COS x, where x is an angle of rotation of said direct current motor as measured from a reference angular position thereof, and A and B are constants; (c) a command signal generating unit which produces a second sine-wave signal C·SIN y and a second cosine-wave signal D·COS y, where y is an angle of rotation of said command signal generating unit as measured from a reference angular position thereof, and C and D are constants; (d) an arithmetic circuit connected to said position signal generating unit and said command signal generating unit for receiving, as inputs thereto, said first sine- and cosine-wave signals A·SIN x and B·COS x and said second sine- and cosine-wave signals C·SIN y and D·COS y and producing, as an output therefrom, a sine-wave signal E·SIN (y-x), where E is a constant; and (e) a driver circuit connected to said arithmetic circuit for amplifying said sine-wave signal E·SIN (y-x) and providing a thus amplified sine-wave signal E·SIN (y-x) to said direct current motor, whereby said direct current motor is rotated in accordance with the signals produced from said command signal generating unit.
Claim 5
Dependent Claim
45 words
A DC servomotor system according to claim 2 wherein said command signal generating unit includes a manually controlled rotatable shaft and means for producing said second sine- and cosine-wave signals C·SIN y and D·COS y corresponding to an angle of rotation of said rotatable shaft.
Claim 6
Dependent Claim
25 words
A DC servomotor system according to claim 3 wherein said position signal generating unit and said command signal generating unit each includes a sine-cosine potentiometer.
Claim 7
Dependent Claim
257 words
A DC servomotor system comprising: (a) a first direct current motor; (b) a first position signal generating unit connected to said first direct current motor for producing, in response to rotary movement of said first direct current motor, a first sine-wave signal A·SIN x and a first cosine-wave signal B·COS x, where x is an angle of rotation of said first direct current motor as measured from a reference angular position thereof, and A and B are constants; (c) a second direct current motor; (d) a second position signal generating unit connected to said second direct current motor for producing, in response to rotary movement of said second direct current motor, a second sine-wave signal C·SIN y and a second cosine-wave signal D·COS y, where y is an angle of rotation of said second direct current motor as measured from a reference angular position thereof, and C and D are constants; (e) an arithmetic circuit connected to said first and second position signal generating units for receiving, as inputs thereto, said first sine- and cosine-wave signals A·SIN x and B·COS x and said second sine- and cosine-wave signals C·SIN y and D·COS y, and producing as an output therefrom, a sine-wave signal E·SIN (y-x), where E is a constant; and (f) a driver circuit connected to said arithmetic circuit for amplifying said sine-wave signal E·SIN (y-x) and providing a thus amplified sine-wave signal E·SIN (y-x) to said first direct current motor, whereby said first direct current motor is rotated following rotation of said second direct current motor.
Claim 8
Dependent Claim
257 words
A DC servomotor system comprising: (a) a first direct current motor; (b) a first position signal generating unit connected to said first direct current motor for producing, in response to rotary movement of said first direct current motor, a first sine-wave signal A·SIN x and a first cosine-wave signal B·COS x, where x is an angle of rotation of said first direct current motor as measured from a reference angular position thereof, and A and B are constants; (c) a second direct current motor; (d) a second position signal generating unit connected to said second direct current motor for producing, in response to rotary movement of said second direct current motor, a second sine-wave signal C·SIN y and a second cosine-wave signal D·COS y, where y is an angle of rotation of said second direct current motor as measured from a reference angular position thereof, and C and D are constants; (e) an arithmetic circuit connected to said first and second position signal generating units for receiving, as inputs thereto, said first sine- and cosine-wave signals A·SIN x and B·COS x and said second sine- and cosine-wave signals C·SIN y and D·COS y, and producing as an output therefrom, a sine-wave signal E·SIN (y-x), where E is a constant; and (f) a driver circuit connected to said arithmetic circuit for amplifying said sine-wave signal E·SIN (y-x) and providing a thus amplified sine-wave signal E·SIN (y-x) to said first direct current motor, whereby said first direct current motor is rotated following rotation of said second direct current motor.
Claim 9
Dependent Claim
43 words
A DC servomotor system according to claim 5 wherein said first direct current motor is connected to and drives a rotating hook shaft of a sewing machine and said second direct current motor is connected to and drives an arm shaft of same.
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) | 1985-08-23 | 1986-02-22 | 1986-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-23 | 1990-02-22 | 1990-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-23 | 1994-02-22 | 1994-08-24 | $7700.00 | Window Closed / Lapsed |