US4497997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for metal arc welding with constant currents
Assignee: UTP Schweissmaterial GmbH and Co KG
•
Filing: 1983-05-20
•
Granted: 1985-02-05
•
Expires: 2003-05-20
Abstract
Abstract The invention relates to a process and an apparatus for metal arc welding with a consumable electrode. A pulsating current is supplied to the electrode from a constant current source. During the interpulse periods between pulses there flows a minimum current which is at least sufficient to maintain the arc. The switch from pulse current to interpulse current occurs as a function of the arc voltage, with switching to pulse current occurring if a minimum voltage is detected and to interpulse current occurring if a maximum voltage is detected. Compared with conventional metal arc welding with a consumable electrode, this method offers the advantage of a better welding quality.
Inventors
- 👤 Peter W. Bodewig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:43
CPC Classifications
B; B23; B23K; B23K9/00; B23K9/09; B23K9/091; B23K9/093
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
68 words
A metal arc welding method, wherein current is supplied to a consumable electrode for welding a workpiece, comprising the steps of: when the arc voltage reaches a predetermined low level, setting the arc current at a high constant value which ensures burn-off of the electrode; and when the arc voltage reaches a predetermined high level, setting the arc current at a low constant value to maintain the arc.
Claim 2
Dependent Claim
68 words
A metal arc welding method, wherein current is supplied to a consumable electrode for welding a workpiece, comprising the steps of: when the arc voltage reaches a predetermined low level, setting the arc current at a high constant value which ensures burn-off of the electrode; and when the arc voltage reaches a predetermined high level, setting the arc current at a low constant value to maintain the arc.
Claim 3
Dependent Claim
20 words
The method according to claim 1, wherein said low constant value is sufficiently low to prevent burn-off of said electrode.
Claim 4
Dependent Claim
22 words
The method of claim 1 or 2, wherein the feed rate of said consumable electrode with respect to said workpiece is variable.
Claim 5
Dependent Claim
24 words
The method of claim 1 or 2, wherein said electrode does not touch said workpiece and said arc is not quenched during said welding.
Claim 6
Dependent Claim
32 words
The method of claim 3, wherein the rate of burn-off said consumable electrode with said high constant current is larger than the feed rate of said electrode with respect to said workpiece.
Claim 7
Dependent Claim
89 words
A metal arc welding device of the type which advances a consumable electrode toward a workpiece, said device comprising: a current source with an output for providing current to the electrode; and a control means for controlling the current source in response to the arc voltage; wherein the current source is switched to output a low constant current by the control means when the arc voltage reaches a high reference voltage and, when the arc voltage reaches a low reference voltage, is switched to output a high constant current.
Claim 8
Dependent Claim
89 words
A metal arc welding device of the type which advances a consumable electrode toward a workpiece, said device comprising: a current source with an output for providing current to the electrode; and a control means for controlling the current source in response to the arc voltage; wherein the current source is switched to output a low constant current by the control means when the arc voltage reaches a high reference voltage and, when the arc voltage reaches a low reference voltage, is switched to output a high constant current.
Claim 9
Dependent Claim
63 words
The device according to claim 6, wherein the control means comprises two parallel-connected comparators, to the inverting inputs of which are respectively applied said high and low reference voltages and said arc voltage, and a changeover switch having an input connected via respective diodes to the outputs of said two comparators for switching said current source between the high and low constant currents.
Claim 10
Dependent Claim
25 words
The device according to claim 6, wherein the current source comprises one of a transistorized and a thyristorized current source with a dynamic current-voltage characteristic.
Claim 11
Dependent Claim
17 words
The device according to claim 6, further comprising means for adjusting the feed rate of the electrode.
Claim 12
Dependent Claim
22 words
The device according to claim 6 wherein said upper and lower reference voltages and said high and low constant currents are adjustable.
Claim 13
Dependent Claim
14 words
The device of claim 6, said current source having a dynamic current voltage characteristic.
Claim 14
Dependent Claim
38 words
The device according to claim 7, wherein the current source comprises a current source with a static current-voltage characteristic, an electronic switch connected to the output of the current source, and a shunt in parallel with the switch.
Claim 15
Dependent Claim
25 words
The device of claim 7, 8, 12 or 9, wherein said high and low reference voltages and said high and low constant currents are adjustable.
Claim 16
Dependent Claim
19 words
The device of claim 7, 8 or 12, further comprising means for adjusting the feed rate of the electrode.
Claim 17
Dependent Claim
27 words
The device of claim 7, 8, 12, 9 or 10, wherein said electrode does not touch said workpiece and said arc is not quenched during said welding.
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) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |