US3766462A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapid feed control for an electric step motor
Assignee: Toshiba Corp
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Filing: 1971-12-30
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Granted: 1973-10-16
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Expires: 1991-12-30
Abstract
Abstract An electric step motor is energized from a variable frequency pulse generator such that feed pulses of a gradually increasing frequency are applied to the step motor during the starting thereof and feed pulses of a gradually decreasing frequency are applied to the step motor during a reduction in the speed thereof. A frequency divider is provided for obtaining a value corresponding to one half or N/2 of a total feed of pulses N. A register is also provided for storing pulses Nm which correspond to the number of feed pulses present during an interval for controlling the step motor from a maximum speed to a minimum one. A digital comparator is provided for comparing the content of the register with the output of the frequency divider and in accordance therewith controls the variable frequency pulse generator and hence provides a speed reduction in the electric step motor.
Inventors
- 👤 M Kubo
- 👤 Y Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:27
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/416; G05B19/19; G05B19/40; H; H02; H02P; H02P8/00; H02P8/04; G05B2219/00; G05B2219/30; G05B2219/41; G05B2219/41326; G05B2219/43; G05B2219/43006
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
182 words
A rapid feed control for an electric step motor comprising: a variable frequency pulse generator having an output thereof for connection to an electric step motor in order to drive the same at a desired rotational speed; subtracting counter means for prestoring a number corresponding to a total number of feed pulses for said step motor, said subtracting counter means subtracting one from said number in response to each pulse fed to said step motor; divider means for dividing by two said total number of feed pulses, first register means for prestoring a number corresponding to the number of pulses required to reduce the speed of said motor from a maximum to a predetermined minimum; digital comparator means for generating a particular output signal in response to a difference between an output of said divider means and an output of said first register means; and, logic circuit means for obtaining a speed reduction signal to be fed to said pulse generator in response to the output signal from said digital comparator means and a predetermined subtraction signal from said subtracting counter means.
Claim 2
Dependent Claim
182 words
A rapid feed control for an electric step motor comprising: a variable frequency pulse generator having an output thereof for connection to an electric step motor in order to drive the same at a desired rotational speed; subtracting counter means for prestoring a number corresponding to a total number of feed pulses for said step motor, said subtracting counter means subtracting one from said number in response to each pulse fed to said step motor; divider means for dividing by two said total number of feed pulses, first register means for prestoring a number corresponding to the number of pulses required to reduce the speed of said motor from a maximum to a predetermined minimum; digital comparator means for generating a particular output signal in response to a difference between an output of said divider means and an output of said first register means; and, logic circuit means for obtaining a speed reduction signal to be fed to said pulse generator in response to the output signal from said digital comparator means and a predetermined subtraction signal from said subtracting counter means.
Claim 3
Dependent Claim
87 words
A rapid feed control for an electric step motor according to claim 1, wherein said logic circuit device includes: means for generating a comparison signal corresponding to the lesser of one half of said total number of feed pulses or said number of pulses required to reduce the speed of said motor from said maximum to said predetermined minimum; and, a coincidence circuit for detecting a coincidence between said comparison signal and the content of said subtracting counter and for emitting a motor speed reduction signal therefrom.
Claim 4
Dependent Claim
162 words
A rapid feed control for an electric pulse motor according to claim 1, wherein said logic circuit device includes: second register means connected to an output of said subtracting counter means for detecting when said subtracting counter means has counted down to said number prestored in said first register means, and, third register means connected to another output of said subtracting counter for detecting when half of said total number of feed pulses has been fed to said step motor and for providing an output corresponding thereto; the output signal s from said second register means being combined in a first AND gate with the output signal from said digital comparator means to provide a speed reduction signal for the step motor, and the output signal from said third register means being combined in a second AND gate with the output signal of said digital comparator means through a NAND gate to provide an alternative speed reduction signal for the step motor.
Claim 5
Dependent Claim
66 words
A rapid feed control for an electric step motor as in claim 1, wherein said logic circuit device includes: first AND gate means coupled to said first register means and to said digital comparator means, second AND gate means coupled to said divider means and to said digital comparator means; and, OR gate means coupled to the outputs of said first and second AND gate means.
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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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |