Patent US3731041A successfully refreshed from Google Patents.
US3731041A
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US
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Method and apparatus for making a tube from a metal strip
Assignee: Hegenscheidt MFD GmbH and Co KG
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Filing: 1971-06-09
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Granted: 1973-05-01
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Expires: 1991-06-09
Abstract
Abstract A device is provided for continuously forming a metal strip to consecutive helical convolutions which together constitute a tube. The abutting edges of the successive convolutions, which edges advance in a helical path at a higher first speed, are intermittently tack-welded by an arc-welding unit. Downstream of this unit is located another arc-welding unit which receives the thus partially welded tube and continuously welds the abutting edges, but at a lower speed.
Inventors
- 👤 H Gebauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:32
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/12; B21C37/122; B23; B23K; B23K33/00; B23K33/004; B23K9/00; B23K9/02; B23K9/032; B23K9/0325
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
156 words
A method of making a tube from a metal strip, comprising the steps of continuously feeding a metal strip in a predetermined direction continuously helically convoluting said strip and forming from the same a tube composed of consecutive convolutions having abutting edges which advance at a first speed in a helical path; intermittently tack-welding said abutting edges at a first welding station and while they advance at said first speed; shifting said tube with the thus tack-welded edges forwardly in said predetermined direction and away from said first welding station; thereupon advancing the abutting edges of the thus shifted tube in a helical path and at a lower second speed; and continuously finish-welding the tack-welded abutting edges at a second welding station downstream of said first welding station and while said abutting edges move at said lower second speed, so as to form a tube composed of consecutive convolutions joined by a continuous helical welded seam.
Claim 2
Independent Claim
156 words
A method of making a tube from a metal strip, comprising the steps of continuously feeding a metal strip in a predetermined direction continuously helically convoluting said strip and forming from the same a tube composed of consecutive convolutions having abutting edges which advance at a first speed in a helical path; intermittently tack-welding said abutting edges at a first welding station and while they advance at said first speed; shifting said tube with the thus tack-welded edges forwardly in said predetermined direction and away from said first welding station; thereupon advancing the abutting edges of the thus shifted tube in a helical path and at a lower second speed; and continuously finish-welding the tack-welded abutting edges at a second welding station downstream of said first welding station and while said abutting edges move at said lower second speed, so as to form a tube composed of consecutive convolutions joined by a continuous helical welded seam.
Claim 3
Dependent Claim
22 words
A method as defined in claim 1, wherein the steps of tack-welding and of finish welding are carried out by arc welding.
Claim 4
Dependent Claim
38 words
A method as defined in claim 1, wherein the steps of shifting said tube comprises severing the tube into individual sections intermediate said first and second welding stations, and shifting each severed section to said second welding station.
Claim 5
Dependent Claim
66 words
A method as defined in claim 1, wherein the step of tack-welding comprises advancing said first welding station in said helical path at said first speed froM a starting position to a terminal position so as to maintain it juxtaposed with a portion of said abutting edges, welding the thus juxtaposed portion of said abutting edges, and returning said first welding station to said starting position.
Claim 6
Dependent Claim
43 words
A method as defined in claim 1, said strip having two opposite major surfaces and said edges each extending from one to the other of said major surfaces; and further comprising the step of bevelling said edges prior to helically convoluting said strip.
Claim 7
Dependent Claim
38 words
A method as defined in claim 5, wherein the step of bevelling said edges comprises providing each of said edges with two bevelled facets which are inclined towards one another in opposite directions from the respective major surfaces.
Claim 8
Dependent Claim
35 words
A method as defined in claim 6, wherein the step of bevelling said edges comprises providing each of said edges with a longitudinally extending rib of substantially right-angular cross-section and located intermediate said bevelled facets.
Claim 9
Dependent Claim
33 words
A method as defined in claim 7; and further comprising the step of also bevelling said rib, alternately from the direction of one of said major surfaces towards the other and vice versa.
Claim 10
Dependent Claim
30 words
A method as defined in claim 7, wherein the step of bevelling comprises so forming said facets that they each include an acute angle with the respectively associated major surface.
Claim 11
Dependent Claim
131 words
In an apparatus for making tubes from metal strips, in combination, first means for continuously helically convoluting an advancing metal strip to form therefrom a tube advancing in a predetermined direction and composed of consecutive convolutions having abutting edges which advance at a first speed and in a first helical path; second means for intermittently tack-welding said abutting edges while the same advance at said first speed; shifting means for shifting said tube with the thus tack-welded seams forwardly in said predetermined direction and away from said second means; third means for advancing said abutting edges of the thus shifted tube in a second helical path but at a lower second speed; and fourth means for continuously finish-welding the tack-welded abutting edges while the same move at said lower second speed.
Claim 12
Dependent Claim
131 words
In an apparatus for making tubes from metal strips, in combination, first means for continuously helically convoluting an advancing metal strip to form therefrom a tube advancing in a predetermined direction and composed of consecutive convolutions having abutting edges which advance at a first speed and in a first helical path; second means for intermittently tack-welding said abutting edges while the same advance at said first speed; shifting means for shifting said tube with the thus tack-welded seams forwardly in said predetermined direction and away from said second means; third means for advancing said abutting edges of the thus shifted tube in a second helical path but at a lower second speed; and fourth means for continuously finish-welding the tack-welded abutting edges while the same move at said lower second speed.
Claim 13
Dependent Claim
45 words
In an apparatus as defined in claim 10, said second means comprising at least one welding unit, and advancing means for advancing said one welding unit periodically in unison with portions of said abutting edges in said first helical path and at said first speed.
Claim 14
Dependent Claim
18 words
In an apparatus as defined in claim 11, said second means comprising at least one other welding unit.
Claim 15
Dependent Claim
15 words
In an apparatus as defined in claim 12, wherein said welding units are arc-welding units.
Claim 16
Dependent Claim
45 words
In an apparatus as defined in claim 12, said tube having a longitudinal axis; and further comprising at least a pair of arms each mounting one of said welding units and each being mounted for displacement longitudinally of said axis and for pivotal movement thereabout.
Claim 17
Dependent Claim
20 words
In an apparatus as defined in claim 14; further comprising mounting means mounting the respective arms for the movements thereof.
Claim 18
Dependent Claim
33 words
In an apparatus as defined in claim 15, said mounting means for each of said arms comprising a journal mounted on the respective arm for adjustment in its position relative to such arm.
Claim 19
Dependent Claim
30 words
In an apparatus as defined in claim 14; and further comprising supply means fast with the respective arms and operative for supplying welding wire to the respectively associated welding unit.
Claim 20
Dependent Claim
23 words
In an apparatus as defined in claim 14; and further comprising geared motor means operative for effecting said movement of the respective arms.
Claim 21
Dependent Claim
22 words
In an apparatus as defined in claim 14; and further comprising displacing means operative for effecting said movements of the respective arms.
Claim 22
Dependent Claim
44 words
In an apparatus as defined in claim 14, said arms each being pivotable about said axis in opposite circumferential directions; and further comprising abutment means associated with each of said arms anD operative for limiting pivoting movement of the respective arm in said directions.
Claim 23
Dependent Claim
42 words
In an apparatus as defined in claim 20; further comprising displacing means operative for effecting said movements of the respective arms, and control means initiating and terminating operation of said control means; and wherein said abutment means cooperates with said control means.
Claim 24
Dependent Claim
101 words
In an apparatus as defined in claim 20; further comprising geared motor means operatively associated with said arms for effecting said pivotal movement of the same; control means initiating and terminating operation of said motor means and being operatively associated with said abutment means so as to be operated in response to engagement of the same by the respective arms; displacing means for effecting said displacement of the same longitudinally of said axis; and optical means carried by the respective arms and operative for controlling operation of said displacing means in dependence upon the degree of longitudinal displacement of said arms.
Claim 25
Dependent Claim
44 words
In an apparatus as defined in claim 14; further comprising cam-roller means mounted on the arm mounting said one welding unit and being in engagement with said abutting edges of said convolutions, and spring means permanently biasing said cam roller means to such engagement.
Claim 26
Dependent Claim
34 words
In an apparatus as defined in claim 14, one of said arms having said one welding unit mounted thereon; and further comprising at least an additional welding unit also mounted on said one arm.
Claim 27
Dependent Claim
36 words
In an apparatus as defined in claim 14, said tube having an inner and an outer side, and said arms being constructed as carriage units and comprising wheels in rolling engagement with one of said sides.
Claim 28
Dependent Claim
15 words
In an apparatus as defined in claim 25, wherein said wheels engage said inner side.
Claim 29
Dependent Claim
15 words
In an apparatus as defined in claim 25, wherein said wheels engage said outer side.
Claim 30
Dependent Claim
14 words
In an apparatus as defined in claim 25, wherein said wheels are spring-loaded rollers.
Claim 31
Dependent Claim
27 words
In an apparatus as defined in claim 25, further comprising displacing means for effecting displacement of said carriage units with reference to the axis of said tube.
Claim 32
Dependent Claim
58 words
In an apparatus as defined in claim 12, said one other welding unit comprising at least one arc-welding head and a guide mounting the same for displacement relative to said tube; and further comprising roller means engaging said tube in the region of said second welding unit and operative for turning said tube about the longitudinal axis thereof.
Claim 33
Dependent Claim
52 words
In an apparatus as defined in claim 30; further comprising severing means for severing respective sections of said tube intermediate said first and second welding units, said roller means engaging the respectively severed sections; and further comprising holding means for holding said sections against axial displacement while engaged by said roller means.
Claim 34
Dependent Claim
41 words
In an apparatus as defined in claim 25, at least one of said carriage units comprising at least one ring-mount; and wherein said fourth means comprises at least one arc-welding head mounted on said ring-mount for displacement circumferentially of the same.
Claim 35
Dependent Claim
30 words
In an apparatus as defined in claim 32, said fourth means further comprising at least one further arc-welding head also mounted on said ring-mount for displacement circumferentially of the same.
Claim 36
Dependent Claim
36 words
In an apparatus as defined in claim 32; further comprising guide means supporting said one carriage and being adjustable relative to said section in a vertical direction and in a direction inclined to said vertical direction.
Claim 37
Dependent Claim
34 words
In an apparatus as defined in claim 34, said guide means comprising a guide rail having a free end portion; and further comprising displaceable support means engaging and displaceably supporting said free end portion.
Claim 38
Dependent Claim
40 words
In an apparatus as defined in claim 10; further comprising electrically operable means for effecting operation of said first through fourth means; and circuit means operatively assocIated with and connecting said electrically operable means with said first through fourth means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |