US3699301A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Edm gap sensing
Assignee: Milacron Inc
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Filing: 1971-11-08
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Granted: 1972-10-17
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Expires: 1991-11-08
Abstract
Abstract An apparatus is disclosed for sensing conditions in a machining gap by detecting a current flow therethrough. The normal application of low power pulses from an oscillator circuit to a power switching circuit is delayed for a predetermined period of time. During this period of time, a sensing signal is applied to the machining gap through a high resistance gap sensing circuit; and the current through the sensing circuit is detected thereby providing an accurate and reliable indicator of conditions in the machining gap.
Inventors
- 👤 Jerry E Losey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:15
CPC Classifications
B; B23; B23H; B23H1/00; B23H1/02; B23H1/022
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
A circuit for use with an EDM power supply comprised in part of a power switching circuit responsive to a DC source and an oscillator circuit for producing output machining pulses to a machining gap, wherein the improvement comprises: a. means connected to the oscillator circuit for inhibiting the occurrence of each machining pulse for a predetermined period of time; b. means connected between the machining gap and the DC source and responsive to the inhibiting means for applying a sensing signal to the machining gap during said predetermined period of time; and c. means responsive to the sensing signal for measuring current through the machining gap during the predetermined period of time.
Claim 2
Dependent Claim
113 words
A circuit for use with an EDM power supply comprised in part of a power switching circuit responsive to a DC source and an oscillator circuit for producing output machining pulses to a machining gap, wherein the improvement comprises: a. means connected to the oscillator circuit for inhibiting the occurrence of each machining pulse for a predetermined period of time; b. means connected between the machining gap and the DC source and responsive to the inhibiting means for applying a sensing signal to the machining gap during said predetermined period of time; and c. means responsive to the sensing signal for measuring current through the machining gap during the predetermined period of time.
Claim 3
Dependent Claim
162 words
A circuit for use with an EDM power supply comprised in part of a power switching circuit responsive to a DC source and low power pulses from an oscillator circuit for supplying, on a power supply output, machining pulses to a machining gap, wherein the improvement comprises: a. means responsive to each of the low power pulses for producing a control signal for a predetermined period of time; b. means connected between an oscillator circuit and the power switching circuit and responsive to the control signal for electrically disconnecting the oscillator circuit from the power switching circuit in response to the control signal; c. means connected between the DC source and the power supply output and responsive to the producing means for applying a sensing signal to the machining gap in response to each of the low power pulses; and d. means responsive to said sensing signal for detecting a current signal through the machining gap during the predetermined period of time.
Claim 4
Dependent Claim
162 words
A circuit for use with an EDM power supply comprised in part of a power switching circuit responsive to a DC source and low power pulses from an oscillator circuit for supplying, on a power supply output, machining pulses to a machining gap, wherein the improvement comprises: a. means responsive to each of the low power pulses for producing a control signal for a predetermined period of time; b. means connected between an oscillator circuit and the power switching circuit and responsive to the control signal for electrically disconnecting the oscillator circuit from the power switching circuit in response to the control signal; c. means connected between the DC source and the power supply output and responsive to the producing means for applying a sensing signal to the machining gap in response to each of the low power pulses; and d. means responsive to said sensing signal for detecting a current signal through the machining gap during the predetermined period of time.
Claim 5
Dependent Claim
98 words
a control signal having a duration at least equal to the duration of said timing signal, b. a switching circuit connected to the oscillator circuit and responsive to the control signal for terminating the application of low power pulses from the oscillator circuit to the power switching circuit; c. a gap sensing circuit connected between the machining gap and the DC source and responsive to the timing signal for applying a sensing signal to the machining gap; and d. a detection circuit connected to the gap sensing circuit for measuring current therethrough in response to the sensing signal.
Claim 6
Dependent Claim
98 words
a control signal having a duration at least equal to the duration of said timing signal, b. a switching circuit connected to the oscillator circuit and responsive to the control signal for terminating the application of low power pulses from the oscillator circuit to the power switching circuit; c. a gap sensing circuit connected between the machining gap and the DC source and responsive to the timing signal for applying a sensing signal to the machining gap; and d. a detection circuit connected to the gap sensing circuit for measuring current therethrough in response to the sensing signal.
Claim 7
Dependent Claim
28 words
The apparatus of claim 2 wherein the applying means comprises a sensing circuit having a resistance approximately 100 times greater than the resistance of the power switching circuit.
Claim 8
Dependent Claim
46 words
The apparatus of claim 3 wherein the resistance of the sensing circuit has a magnitude for producing a time constant in the range of from 0.02 X 10 6 to 0.06 X 10 6 in a circuit comprised of said sensing circuit and the machining gap.
Claim 9
Dependent Claim
64 words
A circuit for use with an EDM power supply comprised in part of a power switching circuit responsive to a DC source and low power pulses from an oscillator circuit for supplying machining pulses to a machining gap formed between an electrically conductive tool and an electrically conductive workpiece, wherein the improvement comprises: a. a control circuit responsive to the oscillator circuit for producing,
Claim 10
Dependent Claim
64 words
A circuit for use with an EDM power supply comprised in part of a power switching circuit responsive to a DC source and low power pulses from an oscillator circuit for supplying machining pulses to a machining gap formed between an electrically conductive tool and an electrically conductive workpiece, wherein the improvement comprises: a. a control circuit responsive to the oscillator circuit for producing,
References Cited (Backward Citations)
US3609281A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |