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(11) | EP 0 343 973 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Improvenments in helically formed tubing Schraubennahtrohre Tubes à joint hélicoidal |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0002] It is known to form metal tubing by a process comprising the steps of forming marginal flanges on an elongate sheet metal strip, feeding said strip longitudinally to a forming head whereby said strip becomes wound helically to bring the opposite edges of the strip and the associated flanges into mating engagement, and clinching together the mating flanges of the strip to form a locked seam by means of clinching rollers which comprise an external clinching roller having a groove shaped in cross-section to correspond with the profile of a locked seam to be formed on the external side of the wall of the tubing and an internal support roller having a cylindrical support surface facing said groove of the clinching roller, see for example G.B-A-1599379.
[0003] Such helically formed lock-seam tubing has a variety of uses. The tubing is usually of generally cylindrical configuration, although for some purposes it is desired that the tubing be corrugated. Corrugation of lock-seam tubing requires additional manufacturing steps that correspondingly increase the cost of the tubing.
[0004] Accordingly an object of the invention is to provide a simple means of forming corrugated, helically wound tubing.
[0005] In accordance with the invention this object is achieved by providing the external clinching roller with a further groove into which the other roller extends, whereby the rollers are effective simultaneously to form the locked seam and to displace the seam radially away from the plane of the metal strip in an outward direction, thereby forming an outwardly projecting helical corrugation in the finished tube.
[0006] Further preferred features and advantages of the invention will become apparent from the accompanying description of one example of the invention, taken in conjunction with the accompanying drawing and any accompanying Claims.
[0007] The single figure of the accompanying drawing is a sectional elevation of the forming head of a machine for the production of helically wound lock-seam tubing, shown in the process of forming such tubing.
[0008] Referring to the drawing, the reference numeral 1 illustrates the forming head of a machine for the production of helical lock-seam tubing. The machine is of generally known type including means for feeding a metal strip into the forming head 1, and means for forming on the longitudinal edges of the metal strip flanges that are interlocked with one another in the finished tubing. Such features of the machine will be familiar to one skilled in the art of the production of helically wound lock-seam tubing, and will therefore not be further described in detail.
[0009] Suffice it to say that at the point in the machine at which the finished lock-seam is produced, the machine is provided with a pair of clinching rollers 2 and 3, of which the roller 2 is supported for rotation within the tubing at the point of formation of a closed helix of the metal strip, via a bracket 4 secured to the forming head 1. The roller 3 is mounted externally of the tubing via a further bracket 5 secured to the frame of the machine in a manner not shown.
[0010] The external roller 3 has a circumferential groove 6 which, in cooperation with the circumference of roller 2 serves to effect closure and compression of the lock-seam of the tubing substantially in the manner of known machines. However, unlike known machines the groove 6 of roller 3 is located within a recess defined by a further groove 7 of the clinching roller 3. The roller 2 is of correspondingly larger diameter, or is displaced radially relatively to the axis of the formed tubing, so that it extends into the groove 7 of the clinching roller 3.
1. A process for the formation of helically seamed tubing comprising the steps of
forming marginal flanges on an elongate sheet metal strip, feeding said strip longitudinally
to a forming head whereby said strip becomes wound helically to bring the opposite
edges of the strip and the associated flanges into mating engagement, and clinching
together the mating flanges of the strip to form a locked seam by means of clinching
rollers which comprise an external clinching roller (3) having a groove (6) shaped
in cross-section to correspond with the profile of a locked seam to be formed on the
external side of the wall of the tubing and an internal support roller (2), having
a cylindrical support surface facing said groove (6) of the clinching roller (2),
characterised in that the external roller (3) has a further groove (7) into which
the other roller (2) extends whereby the rollers (2,3) are effective simultaneously
to form the locked seam and to displace the seam radially away from the plane of the
metal strip in an outward direction, thereby forming an outwardly projecting helical
corrugation in the finished tube.
2. A machine for the formation of helically wound tubing comprising a forming head
(1) associated with means for feeding thereto an elongate metal strip having marginal
flanges, whereby said strip is wound helically to bring said flanges into mating engagement,
and clinching rollers (2,3) for clinching together said flanges to form a locked seam,
said clinching rollers (2,3) comprising an external clinching roller (3) having a
groove (6) shaped in cross-section to correspond with the profile of a locked seam
to be formed on the external side of the wall of the tubing and an internal support
roller (2), having a cylindrical support surface facing said groove (6) of the clinching
roller (2), characterised in that the external roller (3) has a further groove (7)
into which the other roller (2) extends whereby the locked seam is radially outwardly
displaced during clinching to form an external helical corrugation in the tube.
1. Verfahren zur Herstellung von Schraubennahtrohren umfassend die Stufen der Bildung
von Randflanschen eines Blechstreifens, der Zuführung dieses Blechstreifens in Längsrichtung
zu einem Formkopf, wobei der Streifen schraubenförmig aufgewickelt wird um die gegenüberliegenden
Kanten des Streifens und die zugeordneten Flansche in Eingriff miteinander zu bringen
sowie das Verbördeln der aneinanderliegenden Flansche des Streifens zur Bildung einer
Verriegelungsnaht mit Hilfe von Bördelrollen, die eine äußere Bördelrolle (3) mit
einer Nut (6) umfassen, deren Querschnitt mit dem Profil der auf der Außenseite der
Wand des Rohrs zu bildenden Verriegelungsnaht entspricht und einer inneren Stützrolle
(2) mit einer zylindrischen, der Nut (6) der Bördelrolle (2) gegenüberliegenden Stützfläche,
dadurch gekennzeichnet, daß die äußere Rolle (3) eine weitere Nut (7) aufweist, in
welche die andere Rolle (2) sich erstreckt, wobei die Rollen (2, 3) so zusammenwirken,
daß sie gleichzeitig die Verriegelungsnaht bilden und die Naht radial von der Ebene
des Metallstreifens nach außen versetzen, wodurch eine nach außen vorspringende Sicke
des fertigen Rohrs gebildet wird.
2. Vorrichtung zur Herstellung von Schraubennahtrohren mit einem Formkopf (1) mit
Einrichtungen zum Zuführen eines langgestreckten Blechstreifens mit Randflanschen,
wobei der Streifen schraubenförmig aufgewickelt wird um die genannten Flansche in
Eingriff miteinander zu bringen, sowie mit Bördelrollen (2, 3) zum Verbördeln der
Flansche zur Bildung einer Verschlußnaht, wobei die Bördelrollen (2, 3) eine äußere
Bördelrolle (3) mit einer Nut umfassen, deren Querschnitt dem Profil der Verriegelungsnaht
entspricht, die auf der Außenseite der Wand des Rohrs gebildet werden soll, sowie
eine innere Stützrolle (2) mit einer der Nut (6) der Bördelrolle (3) gegenüberliegenden
zylindrischen Abstützfläche, dadurch gekennzeichnet, daß die äußere Rolle (3) eine
weitere Nut (7) aufweist, in welche die andere Rolle (2) sich erstreckt, derart, daß
die Verriegelungsnaht beim Verbördeln radial nach außen versetzt wird um eine äußere
schraubenförmige Sicke im Rohr zu bilden.
1. Procédé pour former un tube à jonction hélicoïdale sertie, comprenant les stades
suivants : former des rebords marginaux sur une bande de tôle métallique allongée,
amener cette bande dans le sens de sa longueur à une tête de formage, grâce à laquelle
la bande est enroulée en hélice pour amener en coopération étroite les bords opposés
de la bande et les rebords associés, et sertir ensemble les rebords conjugués de la
bande pour former une jonction agrafée sertie au moyen de galets de sertissage, qui
comprennent un galet de sertissage extérieur (3) ayant une gorge (6) dont la section
transversale correspond au profil de la jonction agrafée sertie à former sur le côté
extérieur de la paroi du tube et un galet de support intérieur (2), ayant une surface
d'appui cylindrique en vis-à-vis de cette gorge (6) du galet de sertissage (3), caractérisé
en ce que le galet extérieur (3) a une autre gorge (7) dans laquelle pénètre l'autre
galet (2), d'où il résulte que les galets (2,3) coopèrent ensemble pour, simultanément,
former la jonction agrafée sertie et déplacer cette jonction radialement vers l'extérieur
en l'éloignant de la bande métallique, formant ainsi une ondulation hélicoïdale saillant
vers l'extérieur dans le tube terminé.
2. Machine pour former un tube à jonction hélicoïdale sertie, comprenant une tête
de formage (1) associée à des moyens pour lui amener une bande métallique allongée
ayant des rebords marginaux, tête grâce à laquelle la bande est enroulée en hélice
pour amener en coopération étroite lesdits rebords, et des galets de sertissage (2,3)
pour sertir ensemble ces rebords et former une jonction agrafée sertie, ces galets
de sertissage (2,3) comprenant un galet de sertissage extérieur (3) ayant une gorge
(6) dont la section transversale correspond au profil de la jonction agrafée sertie
à former sur le côté extérieur de la paroi du tube et un galet support intérieur (2),
ayant une surface d'appui cylindrique en vis-à-vis de cette gorge (6) du galet de
sertissage (3), caractérisée en ce que le galet extérieur (3) a une autre gorge (7)
dans laquelle pénètre l'autre galet (2), d'où il résulte que la jonction agrafée sertie
est déplacée radialement vers l'extérieur pendant le sertissage pour former une ondulation
hélicoïdale extérieure dans le tube.