US3766459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic stepping drive for dc torque motor
Assignee: Landis Tool Co
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Filing: 1971-08-25
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Granted: 1973-10-16
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Expires: 1991-08-25
Abstract
Abstract A control system for a machine tool having a direct current motor capable of rotating the motor shaft in a series of discrete steps through a range and maintaining the shaft in position between the steps. The motor is controlled by a digital to analog converter which receives an input having a bi-directional digital counter. A pulse generator inputs a preselected number of pulses in a preselected direction; an encoder responsive to the angular position of the motor shaft produces a fixed number of pulses for a given rotation, and the pulses count the counter in a direction related to the direction of movement of the motor shaft. Circuitry is provided both to match a directional signal with each pulse to control the counter direction and also for buffering all of the pulses to prevent more than one pulse from reaching the bi-directional digital counter at substantially the same time.
Inventors
- 👤 Intosh M Mc
- 👤 D Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:07
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/21; G05B19/23; G05B19/231; G05B2219/00; G05B2219/30; G05B2219/41; G05B2219/41241
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
232 words
A control arrangement for a servomotor system, the combination comprising: counting means for counting a series of pulses in increasing or decreasing order and producing digital output signals representative of the pulses counted, converter means connected in controlling relation with the servomotor system and operable in response to receipt of the digital output signals from said counting means for supplying a corresponding analogue signal to the servomotor system to effect rotational movement of the servomotor, control means for supplying pulses to said counting means in increasing or decreasing order with each pulse corresponding to a unit of rotational movement of the servomotor system, said control means being operable in response to receipt of a series of positioning signals representative of a predetermined rotational position for supplying corresponding pulses to said counting means in corresponding increasing or decreasing order, encoding means operable in response to the rotational movement of the servomotor system for producing feedback signals each indicative of a unit of rotational movement of the servomotor to the predetermined position, and said control means being operable in response to receipt of the feed-back signals from said encoding means for supplying corresponding pulses to said counting means in an opposite increasing or decreasing order to reduce the count of pulses and the corresponding analogue signal being supplied to said converter means as the rotational movement of the servomotor approaches the predetermined rotational position.
Claim 2
Dependent Claim
232 words
A control arrangement for a servomotor system, the combination comprising: counting means for counting a series of pulses in increasing or decreasing order and producing digital output signals representative of the pulses counted, converter means connected in controlling relation with the servomotor system and operable in response to receipt of the digital output signals from said counting means for supplying a corresponding analogue signal to the servomotor system to effect rotational movement of the servomotor, control means for supplying pulses to said counting means in increasing or decreasing order with each pulse corresponding to a unit of rotational movement of the servomotor system, said control means being operable in response to receipt of a series of positioning signals representative of a predetermined rotational position for supplying corresponding pulses to said counting means in corresponding increasing or decreasing order, encoding means operable in response to the rotational movement of the servomotor system for producing feedback signals each indicative of a unit of rotational movement of the servomotor to the predetermined position, and said control means being operable in response to receipt of the feed-back signals from said encoding means for supplying corresponding pulses to said counting means in an opposite increasing or decreasing order to reduce the count of pulses and the corresponding analogue signal being supplied to said converter means as the rotational movement of the servomotor approaches the predetermined rotational position.
Claim 3
Dependent Claim
66 words
A control arrangement for a servomotor system according to claim 1: said control means further including anti-coincidence means for receiving the positioning signals and the feedback signals, said anti-coincidence means permitting operation of said control means in response to only one of the signals at a time, and said anti-coincidence means being operable to store the other received signal for subsequent operation of said control means.
Claim 4
Dependent Claim
261 words
A control arrangement for a servomotor system according to claim 1: said converter means being operable to produce analogue signals extending over a bipolar range to effect forward rotational movement of the servomotor system with analogue signals of one polarity and reverse rotational movement of the servomotor system with analogue signals of the opposite polarity, said counting means producing a range of digital output signals corresponding to the bipolar range of analogue signals and being operable in response to an adding directional signal for counting incoming pulses in an increasing order and being operable in response to a subtracting directional signal for counting incoming pulses in a decreasing order, said control means being operable in response to receipt of positioning signals corresponding to a predetermined rotational position in one rotational direction for supplying a corresponding adding or subtracting directional signal to said counting means to control the counting of incoming puLses in a corresponding increasing or decreasing order to effect rotational movement of the servomotor in the one rotational direction to the predetermined position, and said control means being operable in response to receipt of feedback signals from said encoding means produced in response to rotational movement of the servomotor in the one rotational direction for supplying an opposite corresponding adding or subtracting directional signal to said counting means to control the counting of incoming pulses in a corresponding increasing or decreasing order to reduce the count of pulses and the corresponding analogue signal produced by said converter means as the rotational movement of the servomotor approaches the predetermined rotational position.
Claim 5
Dependent Claim
149 words
A control arrangement for a servomotor system according to claim 3: said encoding means being operable to produce first and second series of phase related feedback signals with the first series of feedback signals leading in phase the second series of feedback signals in response to rotational movement of the servomotor system in a first direction and with the first series of feedback signals lagging in phase the second series of feedback signals in response to rotational movement of the servomotor system in a second direction, and said control means including motor direction feedback means receiving the first and second series of feedback signals from said encoding means and being operable to detect the direction of rotational movement of the servomotor and supply a corresponding adding or subtracting directional signal to said counting means to control the counting of pulses produced in response to receipt of the feedback signals.
Claim 6
Dependent Claim
66 words
A control arrangement for a servomotor system according to claim 3: said control means further including anti-coincidence means for receiving the positioning signals and the feedback signals, said anti-coincidence means permitting operation of said control means in response to only one of the signals at a time, and said anti-coincidence means being operable to store the other received signal for subsequent operation of said control means.
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) | 1976-10-15 | 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 |