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US4772776A Expired / Lapsed US ⏱️ 0.0 years remaining

Automatic welding with arc striking retry

Assignee: Hitachi Industrial Equipment Systems Co Ltd
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Filing: 1987-01-07
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Granted: 1988-09-20
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Expires: 2007-01-07
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Abstract

Abstract A welding expectation path is taught beforehand, and an operation for striking an electric arc is executed at a point on the path. If the electric arc does not appear, the operation for striking the electric arc is executed at a different point on the path. When the electric arc has appeared, a welding torch is once returned to a welding start expectation point while the electric arc is held, and it performs welding from the welding start expectation point toward a welding end expectation point.

Inventors

  • 👤 Tusaka Siina

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 19:01
CPC Classifications
B; B23; B23K; B23K37/00; B23K9/00; B23K9/06; B23K9/067; G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/406; G05B19/4067

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 148 words
A method wherein a welding torch is attached to a front end of an arm of an industrial robot, and the industrial robot is moved on the basis of teaching data taught beforehand, thereby to automatically weld a workpiece, comprising the step of causing a welding torch to progress from a welding start expectation point on the workpiece and along a welding expectation line whose start point is the welding start expectation point, the step of executing an arc start in the course of the pregression, the step of causing said welding torch to retrogress from an arc start point where an electric arc has been actually struck, to the welding start expectation point while the electric arc is kept, and the step of causing said welding torch to progress again from the welding start expectation point along the welding expectation line while the electric arc is kept.
Claim 2
Independent Claim 148 words
A method wherein a welding torch is attached to a front end of an arm of an industrial robot, and the industrial robot is moved on the basis of teaching data taught beforehand, thereby to automatically weld a workpiece, comprising the step of causing a welding torch to progress from a welding start expectation point on the workpiece and along a welding expectation line whose start point is the welding start expectation point, the step of executing an arc start in the course of the pregression, the step of causing said welding torch to retrogress from an arc start point where an electric arc has been actually struck, to the welding start expectation point while the electric arc is kept, and the step of causing said welding torch to progress again from the welding start expectation point along the welding expectation line while the electric arc is kept.
Claim 3
Dependent Claim 42 words
An automatic welding method as defined in claim 1, wherein a number of times of the arc start execution for a unit welding section is recorded, and the arc starts are repeatedly executed until the number of times reaches a prescribed value.
Claim 4
Dependent Claim 59 words
An automatic welding method as defined in claim 2, wherein said welding torch is caused to retrogress from the arc start point to the welding start expectation point by the use of positional data which has been stored in the course of the progression of said welding torch from the welding start expectation point to the arc start point.
Claim 5
Dependent Claim 64 words
An automatic welding method as defined in claim 3, wherein: a number of times of the arc start execution in a plurality of unit welding sections are accumulated and stored; and the arc starts are repeatedly executed under a condition of a pilot electric arc which is lower than a rated value in at least one of an arc voltage and an arc current.
Claim 6
Dependent Claim 43 words
An automatic welding method as defined in claim 2, wherein the arc starts are repeatedly executed under a condition of a pilot electric arc which is lower than a rated value in at least one of an arc voltage and an arc current.
Claim 7
Dependent Claim 30 words
An automatic welding method as defined in claim 5, wherein a number of times of the arc start execution in a plurality of unit welding sections are accumulated and stored.
Claim 8
Dependent Claim 59 words
An automatic welding method as defined in claim 5, wherein said welding torch is caused to retrogress from the arc start point to the welding start expectation point by the use of positional data which has been stored in the course of the progression of said welding torch from the welding start expectation point to the arc start point.
Claim 9
Dependent Claim 59 words
An automatic welding method as defined in claim 1, wherein said welding torch is caused to retrogress from the arc start point to the welding start expectation point by the use of positional data which has been stored in the course of the progression of said welding torch from the welding start expectation point to the arc start point.
Claim 10
Dependent Claim 30 words
An automatic welding method as defined in claim 8, wherein a number of times of the arc start execution in a plurality of unit welding sections are accumulated and stored.
Claim 11
Dependent Claim 30 words
An automatic welding method as defined in claim 1, wherein a number of times of the arc start execution in a plurality of unit welding sections are accumulated and stored.
Claim 12
Dependent Claim 43 words
An automatic welding method as defined in claim 1, wherein the arc starts are repeatedly executed under a condition of a pilot electric arc which is lower than a rated value in at least one of an arc voltage and an arc current.
Claim 13
Dependent Claim 109 words
An automatic welding apparatus comprising means for causing a welding torch to progress from a welding start expectation point on a workpiece and along a welding expectation line whose start point is the welding start expectation point, means for executing arc starts repeatedly in the course of the progression, means for causing said welding torch to retrogress from an arc start point where an electric arc has been actually struck, to the welding start expectation point while the electric arc is kept, and means for causing said welding torch to progress again from the welding start expectation point along the welding expectation line while the electric arc is kept.
Claim 14
Dependent Claim 109 words
An automatic welding apparatus comprising means for causing a welding torch to progress from a welding start expectation point on a workpiece and along a welding expectation line whose start point is the welding start expectation point, means for executing arc starts repeatedly in the course of the progression, means for causing said welding torch to retrogress from an arc start point where an electric arc has been actually struck, to the welding start expectation point while the electric arc is kept, and means for causing said welding torch to progress again from the welding start expectation point along the welding expectation line while the electric arc is kept.
Claim 15
Dependent Claim 49 words
An automatic welding apparatus according to claim 12, further including means for determining and storing the number of times of the arc start execution for a unit welding section; and means for terminating the execution of arc starts when the number of stored arc starts reaches a prescribed value.
Claim 16
Dependent Claim 55 words
An automatic welding apparatus according to claim 13, further comprising: means for storing the positional data during the progression of the welding torch from the welding start expectation point to the arc start point during executing of arc starts, and wherein said means for causing said welding torch to retrogress employs the stored positional data.
Claim 17
Dependent Claim 31 words
An automatic welding apparatus according to claim 13, further comprising: means for accumulating and storing the number of times of the arc start execution in a plurality of unit welding sections.
Claim 18
Dependent Claim 56 words
An automatic welding method as defined in claim 12, further comprising: means for storing the positional data during the progression of the welding torch from the welding start expectation point to the arc start point during executing of arc starts, and wherein said means for causing said welding torch to retrogress employs the stored positional data.

References Cited (Backward Citations)

US4647753A Cited
US4578562A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-09-20 1992-03-21 1992-09-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-09-20 1996-03-21 1996-09-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-09-20 2000-03-21 2000-09-20 $7700.00 Window Closed / Lapsed

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