Patent US5254828A successfully refreshed from Google Patents.
US5254828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling electrical resistance spot welding
Assignee: Individual
•
Filing: 1992-05-13
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Granted: 1993-10-19
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Expires: 2012-05-13
Abstract
Abstract Electrical resistance spot welding is controlled by stopping the welding current upon detection of indentation of the work pieces by the electrodes. Indentation is detected indirectly by monitoring the deformation on at least one arm supporting an electrode. The piston of the welding gun cylinder is prevented from displacing in direct proportion to displacements of the electrodes during formation of the weld so that the squeezing force applied by the electrodes to the work piece, and therefore the deformation in the electrode holders, varies as a function of electrode displacements.
Inventors
- 👤 Ariel Stiebel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:13
CPC Classifications
B; B23; B23K; B23K11/00; B23K11/30; B23K11/31; B23K11/314; B23K11/24; B23K11/25; B23K11/252; B23K11/253; B23K11/255
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
160 words
An electrical resistance spot welding apparatus that includes a welding gun having means for moving electrodes into and out of squeezing engagement with a work piece, said apparatus comprising: a controllable source of electrical welding current coupled to said electrodes; means for detecting the mechanical deformation in a work piece, said means for detecting further comprising a piezoelectric transducer mounted to said means for moving said electrodes, said piezoelectric transducer producing a continuous electrical signal indicative of said deformation; means for terminating said welding current, said means for terminating continuously receiving and monitoring said electrical signal from said piezoelectric transducer to immediately terminate the welding current when said electrical signal indicates the occurrence of indentation of the weld; and means for locking said means for moving said electrode holders during thermal expansion of the work pieces at the weld sites during formation of the weld, said means for locking operable to prevent movement of said electrodes during said thermal expansion.
Claim 2
Dependent Claim
160 words
An electrical resistance spot welding apparatus that includes a welding gun having means for moving electrodes into and out of squeezing engagement with a work piece, said apparatus comprising: a controllable source of electrical welding current coupled to said electrodes; means for detecting the mechanical deformation in a work piece, said means for detecting further comprising a piezoelectric transducer mounted to said means for moving said electrodes, said piezoelectric transducer producing a continuous electrical signal indicative of said deformation; means for terminating said welding current, said means for terminating continuously receiving and monitoring said electrical signal from said piezoelectric transducer to immediately terminate the welding current when said electrical signal indicates the occurrence of indentation of the weld; and means for locking said means for moving said electrode holders during thermal expansion of the work pieces at the weld sites during formation of the weld, said means for locking operable to prevent movement of said electrodes during said thermal expansion.
Claim 3
Dependent Claim
47 words
The apparatus according to claim 1, wherein said means for continuously detecting the mechanical deformation comprises a piezoelectric transducer, said transducer producing a signal indicative of the deformation in said means for moving, and wherein said means for controlling is responsive to the sum of the signals.
Claim 4
Dependent Claim
51 words
The apparatus according to claim 1, wherein said piezoelectric transducer is affixed to each of a pair of electrode holders at a location subject to deformation produced by a bending moment in said electrode holder generated by the expansion and contraction of the work piece and electrodes during the welding process.
Claim 5
Dependent Claim
51 words
The apparatus of claim 3, wherein said means for moving further comprises a pair of hands, each of said pair of hands having one of said pair of electrode holders mounted therein, each said transducer being mounted to said electrode holder adjacent to the respective one of said pair of hands.
Claim 6
Dependent Claim
28 words
The apparatus of claim 1, wherein said means for locking comprises a locking device, said device selectively operable to prevent movement of the means for moving the electrodes.
Claim 7
Dependent Claim
28 words
The apparatus of claim 5, wherein said means for moving said electrodes comprises a cylinder and ram and wherein said means for locking is mounted within said cylinder.
References Cited (Backward Citations)
US2396593A
Cited
US2415082A
Cited
FR71169E
Cited
US3404252A
Cited
US3514569A
Cited
US3553420A
Cited
US3727822A
Cited
SU460139A1
Cited
US4341940A
Cited
US4447699A
Cited
JPS5820385A
Cited
US4419558A
Cited
US4472620A
Cited
US4959519A
Cited
US5111020A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-10-18 | 1997-04-19 | 1997-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-18 | 2001-04-19 | 2001-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-18 | 2005-04-19 | 2005-10-19 | $7700.00 | Window Closed / Lapsed |