US3728515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arc welding apparatus
Assignee: Astro ARC Co
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Filing: 1970-09-25
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Granted: 1973-04-17
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Expires: 1990-09-25
Abstract
Abstract Herein described is electronic circuitry used in an arc welding apparatus which provides continuous melting and etching action for the duration of a weld. This is achieved by providing a polarity reversing circuit comprising an electric current storage medium such as an inductor and a current limiter attached across the welding arc electrode and the workpiece. The current limiter allows a certain amount of current to be drawn from the welding power supply to induce electromagnetic energy into the inductor. The current flowing into the inductor and the current limiter bypasses the welding arc and establishes a magnetic field in the inductor. At the termination of the current from the power supply to the electrode, the current induced in the inductor by its collapsing magnetic field flows through the current limiter and through the electrode in a reverse direction, thus causing periodic polarity reversal at the electrode to perform the etching cycle.
Inventors
- 👤 M Gedgaudas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:51
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/09; B23K9/091
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
161 words
In combination with a workpiece and a welding electrode, a welding circuit coupled to said workpiece and said welding electrode to establish a welding arc therebetween, the improvement in said welding circuit comprising: a source of D. C. energy coupled to said welding electrode and said workpiece so as to provide a first path for current flow; means coupled between said source and said workpiece, for serially applying first current pulses of a first polarity through said first current path; an inductor coupled across said electrode and said workpiece so as to provide a second current path which includes said inductor, said workpiece and said electrode; whereby a portion of the energy of each of said first current pulses is stored by said inductor, and produces a current of opposite polarity through said second current path during the intervals between said first current pulses; and current regulating means coupled in series with said inductor for limiting the current through said inductor.
Claim 2
Dependent Claim
161 words
In combination with a workpiece and a welding electrode, a welding circuit coupled to said workpiece and said welding electrode to establish a welding arc therebetween, the improvement in said welding circuit comprising: a source of D. C. energy coupled to said welding electrode and said workpiece so as to provide a first path for current flow; means coupled between said source and said workpiece, for serially applying first current pulses of a first polarity through said first current path; an inductor coupled across said electrode and said workpiece so as to provide a second current path which includes said inductor, said workpiece and said electrode; whereby a portion of the energy of each of said first current pulses is stored by said inductor, and produces a current of opposite polarity through said second current path during the intervals between said first current pulses; and current regulating means coupled in series with said inductor for limiting the current through said inductor.
Claim 3
Dependent Claim
210 words
In combination with a welding apparatus which includes a workpiece and a welding electrode, a welding circuit coupled across said workpiece and said electrode to establish a welding arc therebetween, said welding circuit comprising: a source of D. C. energy coupled to said welding electrode and said workpiece so as to provide a first path of current flow; means coupled between said source and said workpiece for serially applying first current pulses of a first polarity through said first current path; an inductor coupled across said workpiece and said electrode so as to provide a second current path which includes said inductor, said electrode and said workpiece; whereby a portion of the energy of each of said first current pulses is stored by said inductor and produces a current of opposite polarity through said second current path during the intervals between said first current pulses; and current regulating means coupled in series with said inductor for limiting the Current through said inductor, said current regulator means including means for limiting the current through said inductor to a first preselected value during the periods of said first current pulses; and for limiting the current through said inductor to a second preselected current level during the intervals between said first current pulses.
Claim 4
Dependent Claim
210 words
In combination with a welding apparatus which includes a workpiece and a welding electrode, a welding circuit coupled across said workpiece and said electrode to establish a welding arc therebetween, said welding circuit comprising: a source of D. C. energy coupled to said welding electrode and said workpiece so as to provide a first path of current flow; means coupled between said source and said workpiece for serially applying first current pulses of a first polarity through said first current path; an inductor coupled across said workpiece and said electrode so as to provide a second current path which includes said inductor, said electrode and said workpiece; whereby a portion of the energy of each of said first current pulses is stored by said inductor and produces a current of opposite polarity through said second current path during the intervals between said first current pulses; and current regulating means coupled in series with said inductor for limiting the Current through said inductor, said current regulator means including means for limiting the current through said inductor to a first preselected value during the periods of said first current pulses; and for limiting the current through said inductor to a second preselected current level during the intervals between said first current pulses.
Claim 5
Dependent Claim
203 words
In combination with a welding apparatus which includes a workpiece and a welding electrode, a welding circuit comprising: a source of D. C. energy having a positive output terminal and a negative output terminal; a first switch coupled between said positive output terminal of said source of D. C. energy and to said workpiece, the negative output of said source coupled to said welding electrode; an inductor having afirst end coupled to said workpiece and a second end; a transistor having a collector coupled to said second end of said inductor, said transistor having a base and an emitter; a resistive element coupled between said emitter and said welding electrode; a voltage reference source; a voltage divider circuit coupled between said voltage reference and said welding electrode, said voltage divider having a first output and a second output; a second switch operable in unison with said first switch to switch between the first output and the second output of said voltage divider; and a differential amplifier having a first input terminal coupled to the output of said second switch and a second input terminal coupled to said emitter of said transistor, the output of said amplifier coupled to said base of said transistor.
Claim 6
Dependent Claim
203 words
In combination with a welding apparatus which includes a workpiece and a welding electrode, a welding circuit comprising: a source of D. C. energy having a positive output terminal and a negative output terminal; a first switch coupled between said positive output terminal of said source of D. C. energy and to said workpiece, the negative output of said source coupled to said welding electrode; an inductor having afirst end coupled to said workpiece and a second end; a transistor having a collector coupled to said second end of said inductor, said transistor having a base and an emitter; a resistive element coupled between said emitter and said welding electrode; a voltage reference source; a voltage divider circuit coupled between said voltage reference and said welding electrode, said voltage divider having a first output and a second output; a second switch operable in unison with said first switch to switch between the first output and the second output of said voltage divider; and a differential amplifier having a first input terminal coupled to the output of said second switch and a second input terminal coupled to said emitter of said transistor, the output of said amplifier coupled to said base of said transistor.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |