US3873830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for monitoring the quality of welds in seamed tubes
Assignee: Individual
•
Filing: 1972-09-22
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Granted: 1975-03-25
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Expires: 1992-09-22
Abstract
Abstract A method and apparatus for investigating the possible existence of paste weld condition in the seam of a welded tube comprises scanning the area of the weld transverse to the axis of the seam with photo sensitive means. In one embodiment the seam and adjacent area are scanned immediately after welding while the seam is still incandescent and a signal commensurate with the maximum temperature sensed is produced, or alternatively an area integrated temperature responsive signal is developed. In another embodiment, after the tube has cooled the area of blue metal discoloration surrounding the weld seam is scanned and a color responsive temperature related signal is produced. In all instances, a signal falling below a predetermined level indicates that the seam area failed to attain a sufficiently high temperature during the preceding welding process, hence giving rise to the possibility of a paste weld condition.
Inventors
- 👤 Friedrich M O Forster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:47
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/952; G01N25/00; G01N25/72
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
175 words
Apparatus for determining the quality of a longitudinally welded tube by investigating the dissipated heat energy responsive discoloration on the tube in the weld seam area during the manufacture thereof comprising: a head adapted to rotate having a centrally disposed bore for receiving therein the welded tube which is fed axially through said bore while said head is rotating; means coupled to said head for causing it to rotate; photo responsive electrical sensing means disposed in said bore for rotation with said head and oriented to scan a surface portion of the tube in a direction transverse to the axis of the seam; means disposed for illuminating the scanned surface portion whereby to cause said sensing means to receive light energy reflected from said scanned surface portion, and electrical circuit means coupled in circuit with said sensing means for producing, as the head is rotating and the tube is fed through the bore, an electrical signal indicative of the discoloration on the tube in the seam area produced during the preceding manufacture of the tube.
Claim 2
Dependent Claim
175 words
Apparatus for determining the quality of a longitudinally welded tube by investigating the dissipated heat energy responsive discoloration on the tube in the weld seam area during the manufacture thereof comprising: a head adapted to rotate having a centrally disposed bore for receiving therein the welded tube which is fed axially through said bore while said head is rotating; means coupled to said head for causing it to rotate; photo responsive electrical sensing means disposed in said bore for rotation with said head and oriented to scan a surface portion of the tube in a direction transverse to the axis of the seam; means disposed for illuminating the scanned surface portion whereby to cause said sensing means to receive light energy reflected from said scanned surface portion, and electrical circuit means coupled in circuit with said sensing means for producing, as the head is rotating and the tube is fed through the bore, an electrical signal indicative of the discoloration on the tube in the seam area produced during the preceding manufacture of the tube.
Claim 3
Dependent Claim
95 words
An apparatus for determining the quality of a welded tube as set forth in claim 1, said means for illuminating being secured to said head for rotation therewith; said photo responsive sensing means comprising a pair of sensing means responsive predominantly to light in the red region of the light spectrum, one sensing means disposed for scanning a respective surface portion and the other sensing means being inhibited from scanning the surface portion, and said electrical circuit means including means for producing a signal responsive to the imbalanced spectral condition effective upon said sensing means.
Claim 4
Dependent Claim
206 words
Apparatus for determining the quality of a longitudinally welded tube by investigating the heat dissipation caused discoloration on the tube surface in the weld seam area during the manufacture thereof comprising: a head adapted to rotate having a centrally disposed bore for receiving therein the welded tube which is fed axially through said bore while the head is rotating; means coupled to said head for causing it to rotate; a pair of photo responsive sensing means responsive predominantly to light in the red region of the light spectrum, one sensing means disposed for scanning a respective surface portion and the other sensing means being inhibited from scanning the surface portion; means for illuminating the scanned surface portion secured to said head for rotation therewith, whereby to cause said sensing means to receive light energy reflected from such surface portion, and electrical circuit means coupled in circuit with said sensing means for producing during each rotation of the head as the tube, substantially at ambient temperature, is fed through the bore, a signal responsive to the imbalanced spectral condition effective upon said sensing means, which signal is a pulse whose amplitude is responsive to blue discoloration exhibited by the tube in the area of the weld seam.
Claim 5
Dependent Claim
206 words
Apparatus for determining the quality of a longitudinally welded tube by investigating the heat dissipation caused discoloration on the tube surface in the weld seam area during the manufacture thereof comprising: a head adapted to rotate having a centrally disposed bore for receiving therein the welded tube which is fed axially through said bore while the head is rotating; means coupled to said head for causing it to rotate; a pair of photo responsive sensing means responsive predominantly to light in the red region of the light spectrum, one sensing means disposed for scanning a respective surface portion and the other sensing means being inhibited from scanning the surface portion; means for illuminating the scanned surface portion secured to said head for rotation therewith, whereby to cause said sensing means to receive light energy reflected from such surface portion, and electrical circuit means coupled in circuit with said sensing means for producing during each rotation of the head as the tube, substantially at ambient temperature, is fed through the bore, a signal responsive to the imbalanced spectral condition effective upon said sensing means, which signal is a pulse whose amplitude is responsive to blue discoloration exhibited by the tube in the area of the weld seam.
Claim 6
Dependent Claim
36 words
An apparatus for determining the quality of a welded tube as set forth in claim 3, and additional circuit means coupled for transforming the head rotation responsive cyclically occurring pulse signals to a continuous electrical signal.
References Cited (Backward Citations)
US2989642A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |