US4151450A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective means for feeder of machinery with DC-motor
Assignee: Toyota Motor Corp
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Filing: 1977-07-28
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Granted: 1979-04-24
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Expires: 1997-07-28
Abstract
Abstract A protective means for a feeder of machinery having means for transmitting control signal formed from the differential between a predetermined revolution speed and an actual revolution speed of a DC-motor for driving the feeder, and a means to control current in the DC-motor according to said control signal, thereby protecting the motor against excessive current.
Inventors
- 👤 Nobuo Fukuma
- 👤 Yoshito Kato
- 👤 Kouji Nogami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:16
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/0833; H02H7/0838; H02H7/093; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/903
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
145 words
A protective means for a feeder of machinery with a DC-motor to drive a work-table comprising a detecting means for sensing revolution speed of a main shaft of said DC-motor, a comparator means for transmitting control signals based upon difference measured by comparing the revolution speed thus sensed to a predetermined speed value, a control means for limiting said control signals to a predetermined value in case such control signals are beyond said predetermined value, said control means comprising a means respectively for setting up a first value or a second value as its predetermined value and said first value corresponds to a maximum allowable value of an armature current and said second value corresponds to a value smaller than said maximum allowable armature current, and an armature current control means for adjusting current to an armature of the DC-motor according to said control signals.
Claim 2
Dependent Claim
145 words
A protective means for a feeder of machinery with a DC-motor to drive a work-table comprising a detecting means for sensing revolution speed of a main shaft of said DC-motor, a comparator means for transmitting control signals based upon difference measured by comparing the revolution speed thus sensed to a predetermined speed value, a control means for limiting said control signals to a predetermined value in case such control signals are beyond said predetermined value, said control means comprising a means respectively for setting up a first value or a second value as its predetermined value and said first value corresponds to a maximum allowable value of an armature current and said second value corresponds to a value smaller than said maximum allowable armature current, and an armature current control means for adjusting current to an armature of the DC-motor according to said control signals.
Claim 3
Dependent Claim
16 words
A protective means according to claim 1, wherein said control means is a current control circuit.
Claim 4
Dependent Claim
63 words
A protective means according to claim 1, wherein said armature current control means comprises a triangle wave generator circuit, a threshold circuit to transmit pulse waves by modifying triangular waves from said generator circuit in accordance with control signals from said control means, and ON-OFF switching elements contained in the armature current circuit for switching according to out-put signals from said threshold circuit.
Claim 5
Dependent Claim
63 words
A protective means according to claim 2, wherein said armature current control means comprises a triangle wave generator circuit, a threshold circuit to transmit pulse waves by modifying triangular waves from said generator circuit in accordance with control signals from said control means, and ON-OFF switching elements contained in the armature current circuit for switching according to out-put signals from said threshold circuit.
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) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |