Method and apparatus for detecting surface contamination in a weld area
First Claim
1. A method for welding first and second pieces of metal together with a welding system comprising a first electrode, comprising the steps of:
- disposing said first piece of metal relative to said second piece of metal to define an overlapping region said overlapping region defining a longitudinal axis having a first end and a second end;
welding said first and second pieces of metal together in at least said overlapping region, said welding step comprising the steps of;
directing energy to said first electrode to at least assist in said welding step;
advancing said first electrode along said overlapping region from said first end toward said second end while continuing to direct energy to said first electrode, to define a welding period which begins at a first time when said first electrode is substantially positioned at said first end said method further comprising the steps of;
monitoring for an existence of contamination in said overlapping region between said first and second pieces of metal, said monitoring step being performed at least after said first time and continuing throughout at least a substantial portion of said welding period;
identifying said existence of said contamination during said monitoring, while said first electrode is disposed over said surface contamination, said identifying step using said monitoring step; and
in response to identifying said existence of said contamination, diverting said energy from said first electrode.
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Accused Products
Abstract
An apparatus/method for detecting contamination during welding is disclosed. In one embodiment, contamination is detected during the welding of overlapping metal portion used in the production of can bodies. The apparatus monitors the voltage supplied to a welding electrode during welding. When the voltage increases above a predetermined level, which may indicate the presence of contamination, the electrical energy is directed away from the welding roller before the rollers pass the area of contamination. The diverted electrical energy is directed to a short circuiting device, such as a parallel combination of silicon control rectifiers. As such, the electrical energy may be directed away from the welding rollers to prevent damage to the rollers.
25 Citations
20 Claims
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1. A method for welding first and second pieces of metal together with a welding system comprising a first electrode, comprising the steps of:
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disposing said first piece of metal relative to said second piece of metal to define an overlapping region said overlapping region defining a longitudinal axis having a first end and a second end; welding said first and second pieces of metal together in at least said overlapping region, said welding step comprising the steps of; directing energy to said first electrode to at least assist in said welding step; advancing said first electrode along said overlapping region from said first end toward said second end while continuing to direct energy to said first electrode, to define a welding period which begins at a first time when said first electrode is substantially positioned at said first end said method further comprising the steps of; monitoring for an existence of contamination in said overlapping region between said first and second pieces of metal, said monitoring step being performed at least after said first time and continuing throughout at least a substantial portion of said welding period; identifying said existence of said contamination during said monitoring, while said first electrode is disposed over said surface contamination, said identifying step using said monitoring step; and in response to identifying said existence of said contamination, diverting said energy from said first electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for evaluating electrical energy supplied to a welding electrode of a welding unit from an electrical power source during a welding period when said welding electrode is being advanced along a welding line from a first end to a second end, said apparatus comprising:
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a voltage monitor for monitoring, during said welding period, a magnitude of voltage supplied to the welding electrode of the welding unit; a comparator for receiving said magnitude of voltage supplied to the welding electrode from said voltage monitor and for comparing said voltage to a predetermined magnitude of voltage; and a switch interconnected with said comparator, said electrical power source and said welding electrode for diverting, during said welding period, said electrical energy being supplied to said welding electrode when said magnitude of said voltage is larger than said predetermined voltage magnitude. - View Dependent Claims (11, 12, 13, 14)
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15. A method for evaluating electrical energy supplied to a welding electrode of a welding unit during a welding period when said welding electrode is being advanced along a welding line from a first end toward a second end, comprising the steps of:
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supplying electrical energy to the welding electrode of a welding unit; monitoring, during said welding period, a magnitude of a voltage signal supplied to the welding electrode of the welding unit; comparing said magnitude of said voltage signal to a predetermined voltage magnitude; and directing the electrical energy away from the welding electrode of the welding unit, during said welding period, when said magnitude of said voltage signal is larger than said predetermined voltage magnitude. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification