US3070054A - Apparatus for manufacturing pipes and tubes - Google Patents

Description

Dec. 25, 1962 G. GRIETEN 3,070,054

APPARATUS FOR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 4 Sheets-Sheet 1 Fig.

INVENTOR 6067A VE GR/ETEN WWW ATTORNEYS Dec. 25, 1962 G. GRIETEN 3,070,054

APPARATUS FOR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 4 Sheets-Sheet 2 Fig. 9

INVENTOR GU5TAVE GR/ETEN B; gihdnm/ ATTORNEXS Dec. 25, 1962 G. GRIETEN 3,070,054

APPARATUS FOR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 I 4 Sheets-Sheet 3 m4 f :11 1:11 1/ i:

INVENTOR.

B GU5TA VE 'GRIE TEN Affomevs Dec. 25, 1962 G. GRIETEN 3,070,054

APPARATUS F OR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 4 Sheets-Sheet 4 INVENTOR.

BY GUST/l VE GR/ETE/Y United States Patent Office 3,070,05 APPARATUS FOR MANUFACTURING PIPES AND TUBES Gustave Grieten, Alleur, Belgium, assignor to Societe Spiralit, Liege, Beigium Filed Aug. 29, 1957, Ser. No. 681,024 Claims priority, application Belgium Aug. 30, 1956 2 Claims. (Cl. 113-35) The present invention relates to a tube and pipe manufacturing machine. More in particular the present invention relates to a machine for producing tubes or pipes from a metal sheet which is helically rolled and welded at the adjoining rims.

In a known type of tube manufacturing machines the metal sheet is drawn by and rolled around a rotatable mandrel. Some of these machines comprise cylindrical exterior rolls designed to force the metal sheet against the mandrel.

In another type of such machines, the metal sheet is helically wound by pushing the sheet obliquely into a bending device having rolls or disks. In some of the last-mentioned machines the bending is effected by making the metal sheet bend around a cylindrical support or an assembly of wheels or rolls disposed inside of the tube to be formed from the metal sheet. In these cases the bending is obtained by this cylindrical support and two additional cylinders or rolls disposed in front of and behind the cylindrical support, thus effecting a bending of the metal sheet. After leaving the bending device the metal sheet has assumed a tubular configuration. In order to maintain the desired diameter of the tube formed of the helically wound sheet at the welding point it is necessary to subject the two sides of the sheet to the pressure of an exterior wheel or roll. In still other machines known in the art the bending is effected entirely or partly by a substantially cylindrical jacket having a longitudinal opening through which the metal sheet is introduced. Some of these machines have in the area where the metal sheet enters the jacket bending devices such as rolls or the like. These bending devices give an excess bent or curvature to the metal sheet. Consequently, the coil tends to reopen, while the casing is designed to limit this reopening of the coil so that the tube formed of the metal sheet is supported by the walls of the jacket and is prevented from expanding to a diameter superior to the desired diameter of the finished tube.

These devices and in particular the machines of the last-mentioned type having bending devices consisting of rolls and a bent-retaining jacket are unsatisfactory. According to the varying width of the metal sheets and the elasticity coefficient of the metal the residual tension in the sheet at the time of the welding of the rims cannot be properly controlled. In order to limit such tensions the machine must be designed and operate with extreme precision. Furthermore, only a tube of a given diameter can be produced with one of these machines, and the production of tubes or pipes is thus rendered very complicated and costly.

In still other machines the bending devices impart a curvature having a diameter exceeding the diameter of the finished tube and the jacket is only used to give the desired diameter to the helically wound sheet and retain this form and size of the tube until the welding has been done. In this case, too, the sheet retains uncontrolled residual tensions and one individual machine can produce only a tube of a given diameter.

In both of the last-mentioned machines, in which the jacket either has to contribute to shape the tube or has to maintain the shape and size of the tube until the welding can be done, the mutual contact between the jacket 3,070,054 Patented Dec. 25, 1962 and the metal sheet produces a considerable friction. The metal sheet leaves the jacket with traces such as scratches and the like, and the casing has to be provided with a lining of special steel which nevertheless is subject to wear and has to be replaced occasionally.

It is an object of the present invention to provide a tube manufacturing machine of the type bending metal sheets to form a helically wound coil and fixing together the adjoining rims of the helically wound sheet preferably by welding, which is less expensive in construction and operation than known machines.

It is another object of the present invention to provide a tube manufacturing machine of the type bending metal sheets to form a helically wound coil and fixing together the adjoining rims of the helically wound sheet, which can be adapted to produce tubes or pipes of various diameters.

It is a further object of the present invention to provide a tube manufacturing machine of the type bending metal sheets to form a helically wound coil and fixing together the adjoining rims of the helically wound sheet, in which residual tensions of the metal sheet after the bending are virtually eliminated or evenly and uniformly distributed.

It is still a further object of the present invention to provide a tube manufacturing machine of the type bending metal sheets to form a helically wound coil and fixing together the adjoining rims of the helically wound sheet, in which a friction between the metal sheet and the bending device is reduced to a minimum.

It is yet another object of the present invention to provide a tube manufacturing machine of the type bending metal sheets to form a helically wound coil and fixing together the adjoining rims of the helically wound sheet, which does not impair the smooth surface of the metal sheet.

It is still another object of the present invention to provide a tube manufacturing machine of the type bending metal sheets to form a helically wound coil and fixing together the adjoining rims of the helically wound sheet, to provide further improvements of auxiliary devices of the means for fixing together the rims of the helically wound metal sheet by welding.

These objects are achieved by the present invention based on that type of machine producing tubes by attaching to each other the adjoining rims of a helically wound metal sheet and having means for introducing the metal sheet obliquely into a forming device. According to the present invention, the forming device comprises a plurality of bodies, such as rolls, rotating around parallel axes and forming in their totality a substantially cylindrical, though not continuous, jacket, and arranged outside of and at least partly around the metal sheet of which the tube is to be formed and supporting the latter.

According to a preferred embodiment of the present invention there is provided, in addition to the plurality of exterior rolls a plurality of interior rolls which also rotate around axes parallel to the axes around which the exterior rolls rotate, and also forming in their totality a substantially cylindrical, though not continuous, jacket, disposed inside of the metal sheet of which the tube is formed, these interior rolls forming together with the exterior rolls a plurality of successive bending devices acting upon a given point of the metal sheet in succession.

The interior and exterior rolls are preferably arranged equidistantly from the next following exterior or interior roll, respectively, at the circumference of the section of an exterior or interior imaginary circle, respectively, and the interior rolls are so arranged relative to the exterior rolls that in following the circumference of the interior and exterior circles an exterior roll alternates with an interior roll.

Preferably, the exterior and interior rolls are provided with a plurality of sleeves positioned adjacent to each other on the support shafts of the rolls with a certain longitudinal play provided between the juxtaposed sleeves. Furthermore, adjusting means are provided for radially adjusting one or all of the exterior rolls relative to the interior rolls, or vice versa.

Furthermore, the invention provides improvements of the known means for fixing together the adjacent rims of the helically wound metal sheets by welding, consisting of automatic adjustment and control means for adjusting the position of the rims at the welding point and of means for adjusting the position and facilitating the adjustment of the support shoe of the metal sheet at the welding point.

The invention will be more fully appreciated upon the following description of the accompanying drawings, wherein FIGURE 1 is a somewhat schematic top view of the tube forming machine of the invention;

FIGURE 2 is a longitudinally sectional view taken along the line I-I of FIGURE 1 and shows a part of the tube forming device of the invention;

FIGURE 3 is a cross sectional view taken along the line III-III of FIGURE 2 of the tube forming device of the present invention;

FIGURE 4 is a cross sectional view taken along the line IVIV of FIGURE 2 of the tube forming device of the invention;

FIGURE 5 is a schematic view of a control device for the adjustment of the relative distance of the rims of the metal sheet formed to a tube by the apparatus of the invention;

FIGURE 6 is a somewhat schematic view of an adjustable support for the metal sheet at the welding point;

FIGURE 7 is a plan view of the support shown in FIGURE 6;

FIGURE 8 is a front view partly in section of an improved support;

FIGURE 9 is a plan view of the support shown in FIGURE 8.

Referring now to the drawings more in detail and turning first to FIGURE 1, in which some of the known elements have been omitted for the sake of clarity of the drawing, a metal sheet is decoiled from a supply drum and passes over a train of planishing rolls (not shown) and is fed obliquely into the forming device 2 along the guide bars 3, 3' by a pair of feeding rolls 1, 1' which, in turn, are driven by the motor 5a via the reduction gear 5b. For the sake of clarity that part of the metal sheet 1a which has not yet been introduced into the forming device 2 has been omitted. The other, conventional and generally used elements are mounted on the machine frame 5 which can be turned around a pivot 6 in a manner known per se in order to modify the angle of introduction of the metal sheet into the forming device 2.

The forming device 2 with which the present invention is primarily concerned comprises a train of outer rolls 8.

The respective longitudinal axes of these outer rolls 8 are positioned upon an imaginary circle which is coaxial to the tube to be formed. As can be seen from FIGURES 3 and 4 this circle is not entirely closed. The rolls 8 thus form a sort of a jacket partly surrounding the tubularly bent metal sheets, which jacket is, however, interrupted since the rolls are not adjacent to each other, but are spaced, preferably equidistantly from each other.

According to a preferred embodiment of the invention the forming device 2 comprises, in addition to the train of outer rolls 8 a train of interior rolls 7, disposed in an analogous manner to the arrangement of the exterior rolls 8.

The angle defining the segment of the imaginary circle occupied by the exterior rolls is preferably greater than the angle defining the segment of the imaginary circle occupied by the interior rolls.

However, the section of the imaginary circle upon which there are located, preferably equidistantly spaced, the respective centers of the interior rolls 384 through 38-8 comprises preferably more than of a full circle.

The outer rolls 8 are positioned with one of their respective ends (in FIGURE 2 with their left ends) in a side plate 9, whereas the other ends of the rolls 8 are mounted in another side plate 10 located opposite to the side plate 9. The side plates 9 and 10 form the upper part of the machine frame and are attached to the base plate 11 by braces 12 and 13. The base plate 11 is fixed on the ground by bolts 11a passing through elongated slots 11b, so that the entire forming device can be moved in longitudinal direction, ie in the directions in which the longitudinal axis of the tube In formed of the metal sheet extends. The elevation of the forming device 2 can be varied relative to the guide bars 3, 3' by placing suitable lifting and lowering devices underneath the base plate 11.

The rolls of the exterior and the interior roller train are provided with sleeves of which two are shown on the exterior roll 8 in FIGURE 2 designated as 14 and 15. These sleeves are mounted adjacent to each other and coaxially on the shafts for the rolls, such as the shaft 16. A ball bearing 42 can be provided between every pair of adjacent sleeves.

The shaft 16 of the roll 8 shown in FIGURE 2 ends on its respective opposite ends in a flat portion 17 and 18, respectively. Screws 19, 20 turning in nuts 19a, 20a, and attached to the side plates 9 and 10 press against these flat portions 17 and 18 of the shaft 16. The shaft 16 (and, correspondingly, the other shafts of the rolls 8) has prolonged portions 21, and 22 at its left and right extreme end, respectively. These prolongations are guided in slots such as the slots 23 shown in FIGURE 4 provided in guide plates 24, 240, which, in turn, are fixed to the side plates 9 and 10 by screws 26 and 27.

By means of this arrangement the exterior rolls can be displaced radially in regard to the longitudinal axis of the molding device 2.

The interior rolls forming the train of interior rolls 7 are arranged in a similar manner. However, they are not supported at their extreme ends in the identical manner. With their one end they are positioned in the side plate 9 attached to the side plate 9. There are also provided screws, such as screws 28, 28a turning in nuts 29, 29a which are fixed to the side plate 9 and press against fiat end portions 30, 30a of the roll 7. Thus the interior rolls can be radially displaced just as the exterior rolls. The other ends of the interior rolls are positioned in a ring 31 connected to the side plates 9, 9' by connecting rods 32, 33, 34- which latter have threaded ends and are fixed to the side plates by nuts such as nut 35.

Furthermore, screws, such as nuts 36, 36a, are fixed to the ring 31 and receive screws 37, 37a. The ends of these screws press against the flat portions of the shaft 38 of the interior roll. Guide plates 39, 39a fixed by screws 40, 40a hold the shaft in its adjusted position. The plates 39, 39a embrace their corresponding shaft 33 passing through bores in these plates in the same manner as the plate 24 has been described to receive the extreme end 21 of the shaft 16. Some of the shafts of the train of interior rolls can be prolonged beyond the side plate 10 so as to give an additional support to the metal sheet. In order to avoid a rocking motion of the rolls in the ring support 31 there are provided screws, such as the screw 41 opposite to the screw 28.

It is also of advantage to provide collective adjustment means whereby the adjusting screws for a train of rollers, for example the interior rolls or the exterior rolls, as, for

instance, the screws 19, 20 and so forth are turned simultaneously. This can be done, for example, by a transmission gear actuated by a common gear. This common gear operates all the adjusting screws disposed in one plane. By coupling the transmission gears of the two side plates 9, lit), the rolls are made to approach or travel away from the metal sheets simultaneously. With other words, when adjusting the rolls with these collective adjustment means, the axes of the rolls always remain in a parallel position relative to each other as well as relative to the longitudinal axis of the tube formed of the metal sheet. The exact adjustment of the rolls relative to the metal sheet can be effected more accurately by graduated steps provided on the side plates.

It is of course also possible to provide every individual roll with an adjusting device common to two adjusting screws disposed at the two opposite ends of the roll, as for example the adjusting screws 19 and 20.

It is also advantageous to equip the collective adjustment means for simultaneously displacing the rolls with coupling and decoupling means which may be arranged, for example, between the common gear and the gears operating the screws so that every individual screw can be readjusted before operating the several screws simultaneously.

The radial plane through the center of the rolls 7 divide into two equal angles the dihedral angles formed by the radial planes through the centers of the outer rolls 8. Thus, each of three consecutive rolls, such as the three rolls 16-9, 38-8, 16-8, or the three rolls 16-8, 38-7, and 16-7, and so forth, form a complete bending device for the metal sheet passing therethrough.

In order to eliminate those unnecessary portions of the roll over which the metal sheet does not pass and to be able to use rolls of the same length the side plates 9 and 10 can be replaced by warped plates with helical contours. In this case the several exterior and interior rolls remain parallel to each other but their ends are progressively longitudinally displaced. For example, the roll 16-9 retains its position, the end of the roll 16-8 positioned in the side plate 9 is displaced in the direction of the plate It by a certain amount, the extreme end of the roll 16-7 positioned in the plate 9 is displaced in the direction of the plate 10 by twice that amount and so forth, until the roll 16-1, the extreme end of which is positioned in the side plate 9 is located approximately at the point A of FIGURE 2. The interior rolls are to be arranged in an analogous manner.

The present invention also offers a number of further improvements of known elements in sheet bending devices. It has, for example, already been suggested to facilitate the formation of the tube by making approach one another the rims of the metal sheet at the welding point by exerting a pressure against the tube immediately after it has been formed in the forming device and has left the same. The regulation of this pressure was to be effected by the operator attending to the welding.

According to the present invention the comparatively coarse and inaccurate adjustment by an operator is replaced by an automatic control. This automatic control can, for example, be effected by the device shown in FEGURE l and in FIGURE 5.

The formed tube In is pushed by the advancement of screw 91 which, in turn, is actuated by an electric motor 92 capable of forward and reverse motion. A return element consisting of "a piston 43 actuated by a spring 44 mounted at the fixed machine frame tends to open the welding rim. The motor running at forward speed tends to make the rims approach each other. Between the rims as and 46 of the metal sheet to be welded (see FIGURE 5) and a small distance from the welding point there are arranged two friction disks 47 and 48 mounted at the end of a lever 49 and a lever 50, respectively, fulcrumed at 51. The extreme end of the lever 49 is fixed while the extreme end of the lever 50 forms another disk 53. This disk 53 is adapted to come into contact with two electrically conducting strips 54 and 55 mounted together with the disk in the circuit conditioning the change of operation of the motor. If the disk contacts the strip 54, the motor 92 runs in a direction tending to push apart the rims 4-5 and 46. If the disk 53 contacts the strip 55, the motor runs in opposite direction advancing the screw 91, thus tending to push the tube 1a and make the rim of the metal sheet approach at the point of welding. There can also be added a manually operated mechanism as, for example, the shaft 56 having a Cardan joint 57 and a hand wheel 58. Instead of the screw and the electric motor it is also possible to provide hydraulic or pneumatic adjusting means. Furthermore, the adjustment can be initiated by photoelectric cell means detecting the distance between the rims and correspondingly actuating the motor in one direction or the other as the situation may require.

The invention also provides an auxiliary device for the welding installation. A support shoe 59 is disposed underneath the rims and approximately perpendicular to the welding set. The support shoe 59 is cooled in a manner known per se by circulating water entering at 60 and leaving at 61. It is supported by a column slidingly arranged -in a boring of shaft 63 and fixed by screw 68. The shaft 63 bears a platform 64 having longitudinal slots 71 and 72 receiving bolts 69 and 70 which, in turn, are mounted on a platform 65 supporting the platform 64. By fastening the bolts 69 and '76 the two platforms are fixed relative to each other but can be displaced in the range of the elongated slots '71, 72. The movement of the column 62 permits to make the support shoe 59 turn around the axis of column 62. The play of the bolts 69 and '70 permits to modify the direction of a column 62 and the support shoe 59 relative to vertical direction. Since the platform 65 mounted at the end of a two-armed lever 66 pivoted at 67 is actuated by a stretcher 68a it is possible to adjust the height of the support shoe 59. The positioning of the support shoe 59 is very simple and all the adjustments can be located by graduated steps for abutments which facilitates the exact replacement of the support shoe after it has been removed in order to renew its surface.

Since the width of the metal sheets varies, at least portions of the surface of the support shoe may not be in perfect contact with the metal sheet and small defects of the welding may result therefrom. The contact between the support shoe and the metal sheet is improved according to the invention by adding springs tending to push the support shoe against the metal sheet and by replacing the one piece support shoe 59 by an assembly of small support shoes forming a checkerboard and being pushed upwardly against the metal sheet separately. (See FIGURES 8 and 9). By way of an example the FIGURES 8 and 9 show a steel support 81 and a number of small support shoes of copper $2 gliding with a certain play in the bores 87 of the support -81. Each of these little copper shoes has a groove 83 enclosing a fixed guide and detent pin 84 and is adapted to be pushed upwardly against the metal sheet under the influence of spring (35. The entire system can be cooled by circulating water passing through channels 86 in the steel support 81.

Advantages The bending device of the present invention is distinguished from and greatly superior to known bending devices and particularly those bending devices having a continuous forrm'ng jacket. In the present invention there is an interval from one roll to the next roll and from one bending device comprising three rolls to the next bending device having another three rolls, In this interval no bending action is applied to the metal sheet and, consequently, the internal tensions in the sheet are allowed to be evenly distributed without intervention from external forces. Furthermore, each of the rolls is provided with a plurality of adjacent sleeves constituting independent, coaxial revolving elements and allowing for a certain longitudinal play of the metal sheet facilitated by the provision of ball bearings between the adjacent sleeves. This longitudinal play also favors the elimination of elastic tensions and contributes to the uniform distribution of the internal tensions of the metal sheet.

Due to the means for radially adjusting the interior and exterior rolls relative to the central longitudinal axis of the tube, the forming device of the present invention can be adapted to produce tubes or pipes of different diameters.

Furthermore, the individual rolls and hence the groups of three rolls each constituting one of a succession of bending devices are adjustable independently from each other. Consequently, a very exact bending is made possible by the forming device of the present invention.

The automatic adjustment means for the rims of the metal tube to be welded together is more accurate and reliable than the manual adjustment performed by an operator. Defects in the welding together of the rims are thus avoided and a firm and accurate mutual attachment of the rims is facilitated.

The improved support means of the invention auxiliary to the welding installation are extremely mobile and can be displaced in three ditierent directions, thereby greatly facilitating the welding operation.

Furthermore, the composite support means comprising a number of small support shoes affords a more perfect adjustment of the support to uneven metal sheets of varying widths and ensures a better contact between the surface of the support and the metal sheet, thus contributing to a more perfect welding.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions, and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What I claim is:

1. A tube manufacturing machine of the type helically coiling a strip of sheet metal and attaching the adjacent rims of the coiled sheet to each other, having a tube forming device into which the strip of sheet metal is introduced and wherein it is tubularly bent, said device comprising a plurality of rotatable exterior rollers and a plurality of rotatable interior rollers, said exterior rollers being arranged with their respective longitudinal axes upon a segment greater than 180 of an imaginary circle at a predetermined distance from each other, with said longitudinal axes of said rollers being parallel to that of the tube being formed, said exterior rollers externally surrounding at least partly the metal sheet, said interior rollers being arranged opposite the interval between two neighboring rollers of said exterior rollers, and said interior rollers being with their respective longitudinal axes upon a segment of another imaginary circle at a predetermined angular distance from each other and at the inner side of the metal sheet, all of said rollers being mounted for movement toward and away from the axis of the tube being formed, and means for feeding a strip of metal between the exterior and interior rollers at an acute angle to the axis of the rollers and the tube being formed to form a helical tube, whereby tubes of different diameters may be produced by the same machine.

2. A tube manufacturing machine of the type helically coiling a strip of sheet metal and attaching the adjacent rims of the coiled sheet to each other, having a tube forming device into which the strip of sheet metal is introduced and wherein it is tubularly bent, said device comprising a plurality of rotatable exterior rollers and a plurality of rotatable interior rollers, said exterior rollers being arranged with their respective longitudinal axes upon a segment greater than of an imaginary circle at a predetermined distance from each other, with said longitudinal axes of said rollers being parallel to that of the tube being formed, said exterior rollers externally surrounding at least partly the metal sheet, said interior rollers being arranged opposite the center of the interval between two neighboring rollers of said exterior rollers, every three of those neighboring of said exterior and interior rollers forming a triangle thus constituting an independent bending device, and said interior rollers being with their respective longitudinal axes upon a segment of another imaginary circle at a predetermined angular distance from each other and at the inner side of the metal sheet, all of said rollers being mounted for move- ,ment toward and away from the axis of the tube being iformed, and means for feeding a strip of metal between the exterior and interior rollers at an acute angle to the axis of the rollers and the tube being formed to form a helical tube, whereby tubes of difierent diameters may be produced by the same machine.

References Cited in the file of this patent UNITED STATES PATENTS 713,767 Judge Nov. 18, 1902 725,723 Kirk Apr. 21, 1903 1,070,268 Lawton Aug. 12, 1913 1,098,919 Pratt June 2, 1914 1,783,187 Elliott Dec. 2, 1930 1,793,281 Freeze Feb. 17, 1931 1,875,560 Cammen Sept. 6, 1932 1,929,415 Force Oct. 10, 1933 2,059,578 Henning Nov. 3, 1936 2,365,226 Stout Dec. 19, 1944 FOREIGN PATENTS 828,096 Germany Jan. 12, 1952 264,620 Great Britain Jan. 27, 1927 754,020 Great Britain Aug. 1, 1956

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