IL29149A

IL29149A - Method and device for manufacturing helically seamed tube

Info

Publication number: IL29149A
Application number: IL29149A
Authority: IL
Original assignee: Malkki E; Silde V
Priority date: 1966-12-21
Filing date: 1967-12-18
Publication date: 1971-07-28
Also published as: FR1548897A; SE344692B; US3595046A; NO126163B; ES348471A1; CH463437A; AT307209B; GB1168179A; JPS4827198B1; NL6717293A; FI40528B; BE708126A

Description

C O H E N Z E D E & S P I S B A C H REGD. PATENT ATTORNEYS 24, LEVONTIN STR., P. O. B. 1169 I E L ■ A V I V P A T E N T S & D E S I G N S O R D I N A N C E 17352/67 SPECIFICATION METHOD AND DEVICE FOR ¾A KUFA C tlfi IMG HELICALLY SEAMED TUBE ■»3ΐτ*7π nan ay iin •ns-»,>'? Tpnm ^*¾-«¾.

We, EIHO ALBBVO MLKEI, a citizen of Finland, of 18, Et .Hesperiankatu A 2, Helsinki, Finland, and VALFHTIJS SILDE, a citizen of Finland, of 3,linja 23 B, Helsinki, Finland, HEREBY DECLARE the nature of this invention and in what manner the same is fo be performed to be particularly described and ascertained in and by the following statement: This invention relates to a method of and apparatus for making a he Ileally-searned tube from a profiled metal strip which has been performed so that it has two longitudinal edge flanges to be brought into contact with one another and rolled and thereby re-shaped to complete the helical seam.

There are known methods of and apparatus for making a helically-seamed tube from such a profiled metal strip. The profiling of the metal strip may be effected by the apparatus which also completes the seam, or it may be accomplished separately.

The commonest shortcoming of previously known methods and apparatus has been that they usually Include mandrels which extend within the tubes and must be exchanged when it is required to produce tubes of different diameters or to use profiled strips of other widths.

The present invention is therefore intended to provide an improved method and apparatus which can be used without a mandrel extending inside the tube being formed and may be adapted to manufacture tubes of considerably different constant or varying diameters and of frus to-conical or other shapes, for example so that tubes of different diameters may be easily connected to each other.

According to the invention there is employed a method of making a helically-seamed tube from a profiled metal strip which has been performed so that it has two longitudinal edge flanges to be brought into contact with one another and rolled and thereby reshaped to complete the helical seam, the method comprising the steps of feeding the profiled strip forward and deflecting it through 360 degrees, that is through a complete turn or the length of one lead or pitch of the helical seam, thereby or thereafter bringing the said edge glanges into pre-seaming contact with each other, then effecting an initial stage of the seaming operating with the aid of a first rolling device of a kind which at the same time supports the tube that is being formed, then finishing the seaming operation in at least two further stages in which for guidoone and support of the tube is production at least two further rolling devices of the said kind are used, there being no mandrel within the tube and all of said rolling devices beinglocated outside the tube while at the same time supporting the tube, the locations at which all the rolling devices act in forming the seam being such that as viewed in the direction of the longitudinal axis of the tube the said locations all lie on a common imaginary circle concentric with the tube being produced.

The invention further includes the provision of an apparatus for effecting the said method, characterized in that it includes at least three rolling devices comprising rolls which in consecutive stages commence . and continue and finish forming the helical seam of the tube, there being no mandrel P.A. 2 1A9/2 within the tube and all of said rolling devices being located outside the tube and serving at the same time for supporting the bube being made so that other supporting and bracing elements for the tube in the vicinity of the rolling devices are unnecessary. Preferably the rolling devices are movable along guides by means of a screw arrangement whilst the apparatus is in operation so that lengths of tube of frusto-conical or other formation having a decreasing or increasing diameter can be made.

The present invention offers the advantages of simplicity and of facilitating the manufacture of tubes of differing diameters, all of which results in a considerable reduction of the production costs.

The invention is defined in the claims hereinafter, and how it may be performed is further ddescrlbed below with reference to the accompanying drawings, in which by way of example t- Fig. 1 shows parts of an apparatus for use according to the invention, seen from one side, Fig. 2 shows a plan view corresponding to Fig. 1, Fig. 3 shows three profile diagrams representing three different stages in forming a helical seam, Fig. shows three profile diagrams representing the shapes of the flanges in three further alternative forms of completed helical seams, P. A. 2 1A9/2 Fig. 5 shows to an enlarged scale some of the parts shown in Fig. 2, and Fig. 6 shows (From the side as in Fig. l) some parts in a modification of an apparatus to be used according to the invention, with an inset detail view in the direction of the arrows A--A.

Figs. 1 and 2 and, 5 Bhow how a metal strip 1 enters the apparatus, drawn and fed forward by rolls 3 which pre- orm or shape the strip 1 with two longitudinal edge flanges, to have the desired profile so that a profiled strip 2 is produced.

The profiled strip 2 is fed onwards as indicated by the arrows. The strip 2 is deflected through an arc of 366 degrees or one complete turn , forming a coil with the said edge flanges brought into pre-seaming contact w th each other over a length corresponding to one turn or pitch o the helix or screw-line to be followed by the helical seam.

When the strip 2 arrives at a first rolling device 4 the latter effects an initial stage in the formation of the helical seam. Spaced along the length of the next complete turn or pitch of the screw-line, startin from the rolling device , are two urther rolling devices 5 and 6 which in two further stages finish the helical seam, for example the stages may be as represented at a, b, and c in Fig. 3· Each rolling device or 5 is located outside the tube and includes a pair of cooperating rolls between which the said edge flanges for forming the helical seam are re-shaped. These rolling devices are of a kin - which at the same time supports the bube that is being formed.

There is no mandrel within the tube, and other supporting and bracing elements for the tube in the vicinity of the rolling devices are unnecessary.

It is favorable, having regard to the seaming work quality as well as the reliable operation of the entire apparatus, if all the rolls in ¾ie devices and 5 and 6 participating in the seaming operation are positively ddriven, to draw the strip 2 and the tube which is being formed forwards in the direction of the helical seam, all with the same speed. if a pre-profiled strip 2 is used, the rolls 3 are obviously unnecessary, and they may be replaced by any appropriate pre-profiled strip-feeding device, in which case the feed has to be spgrchronised with the traction of the rolls in the rolling devices 4, 5 and 6 for producing the helical seam.

The apparatus comprises a frame 7 with rectilinear guides 8 which are placed to form an acute angle with one another, the rolling devices and 5 being arranged to be movable along the guides 8.

If the width of the strip 2 is changed but the outer diameter of the tube 9 to be produced remains unchanged, the mutual spacing of the rolling devices is adjusted in the longitudinal or axial direction of the tube which is being formed, as required.

P.A. 291 9 2 If it is desired to change the outer diameter of the tube being produced, the roiling devices and 6 are displaced to change their spacing from the axis of the tube, alon rectilinear guides. Fig. 6 shows the rolling devices 5 and 6 mounted on slides 10, each slide 10 being movable alnng two guide bars 13. By tunning a spdmdle 12, which acts through bevel gearing 4ro» to rotate two screw spindles 11 interacting with the slides 10, the slides 10 and the rolling devices and 6 along with them may be positioned as desired The spindle 12 (Fig. 6) may also be arranged, e.g. by means of any appropriate gearing of constant or variable ratio and transmission, to rotate so that there is produced a helically-seamed tube the diameter of which alternately decreases and increases. In order that the rolling devices 5 and 6 mounted according to Fig* 6 may have driven rolls to exercise traction, the power is most suitably transferred to sprockets (not shown) on the slides .10 by means of chain transmissions and further transmitted bytJevel gears to the rolls of the rolling devices 5 and 6. Eaoh rolling device 5 or 6 according to Fig. 6 includes two rolls rotating in opposite directions and pressing the said edge flanges of the etrip to form the helical seam.

In Fig. 3 three different stages a, b and c occurring in the formation of one type of he).ioal seam are shown. These profile shapes of the flanges in the formation of the seam are produced at the locations encircled and indicated by the corresponding reference symbols in Fig. 5. In Pig. some other completed helical seam profiles are represented, hich profiles can be produced with an apparatus and method according to the invention.

The seams illustrated are suitable Cor substantially rigid tubes, but not for flexible tubes.

An apparatus according to the invention can be provided with more than three rolling devices, but there is usually no reason for this the apparatus would merely become unnecessarily complicated, and the achievement of various adjustments would be rendered more difficult.

With an experimental prototype of an apparatus according to the invention, in which three rolling devices have been used, distributed over the length of one turn or pitch of the helical seam produced, with 120 degrees mutual angular displacement, tubes have been seamed with diameters varying from the order of 1 cm up to 1.5 meters. It is easy in actual practice, to achieve even larger diameters if need exists..

Claims

1. P.Α. 2 1 /2 WHAT IS CLAIMED IS* 1. A method of making a helically-seamed tube from a profiled metal strip which has been preformed so that it has two longitudinal edge flanges to be brought into contact with one another and rolled and thereby re-shaped to complete the helical seam, the method comprising the steps of feeding the profiled strip forward and deflecting it through 360 degrees, that is through a complete turn or the length of one lead or pitch of the helical seam, thereby or thereafter bringing the said edge flanges into pre-seaming contact with each other, then effecting an initial stage of the seaming operation with the aid of a first rolling device of a kind which at the same time supports the tube that is being formed, then finishing the seamin operation in at least two further stages in which for guidance and support of the tube in production at least two further rolling devices of the said kind are used, there bein no mandrel within the tube and all of said rolling devices being located outside the tube while at the same time supporting the tube, the locations at which all the rolling degices act in forming the seam being such that as viewed in the direction of the longitudinal axis of the tube the said locations all lie on a common imaginary circle concentric with the tube being produced.

2. A method according to Claim 1, characterized in that there are employed . three of said rolling devices which are equi-spaced over the length of one lead or complete turn o the helical seam with ID degrees mutual angular displacement.

3. A method according to Claim .1 or 2, characterized in that some or all of the rolling devices comprise rolls which are driven so that they pull the strip or partly-formed tube forward in the direction of the helical seam at a speed consistent with the speed at which the profiled strip is being fed. h» An apparatus for effecting a method according to any of Claims 1 to 3» characterised in that it includes at least three rolling devices comprising rolls which in consecutive stages commence and continue and finish forming the helical seam of the tube, there being no mandrel w thin the tube and all of said rolling devices tbeing located outside the tube and serving at the same time for supporting the tube bbing made so that other supporting and bracing elements for the tube in the vicinity of the rolling devices are unnecessary. 5. An apparatus according to Claim h, characterised in that each rolling device includes a pair of cooperating rolls between which the said edge flanges for forming the helical seam are re-shaped. 6. An apparatus according to Claim or 5, characterized in that some or all of the rolls of some or all of the roiling devices are driven so that they P.A. 2 1^ /2 pull the strip or partly- ormed tube forward in the direction of the helical seam being formed. 7. An apparatus according to Claim 4, 5i or 6, characterized in that the mutual spacing of the Tollin devices in the direction of the longitudinal axis of the tube being produced is adjustable so that the apparatus may be used to produce tubes from strips of different didths . 8. An apparatus accordin to any. one of Claims k to 7» characterized in that it includes three rolling devices which are adjustable with respect to each i other so that as viewed in the direction of the longitudinal axis of the tube being produced the locations at which the rolling devices act in forming the seam lie at the apices of an imaginary equilateral triangle. 9* An apparatus according to any one of Claims 4 to 8, characterised in that it includes three rolling devices, two of which are arranged to be movable along rectilinear guides placed to form an acute angle with one another. 10. An apparatus according to Claim 9» characte ised in that the rolling devices are movable along the guides by means of a screw arrangement whilst the apparatus is in operation so that lengths of tube of frusto-conical or other formation having a decreasing or increasing diameter can be made. - - 11. A Method of making helically-seamed tube, substantially as hereinbefore described with reference to the accompanying drawings. 12. An apparatus for making h lically-seamed tube* substantially as hereinbefore described with reference to and as illustrated in Fig. 1 and 2 and 5 or Fig. 6 of the accompanying drawings .