Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3054438 A
Publication typeGrant
Publication dateSep 18, 1962
Filing dateDec 2, 1958
Priority dateDec 2, 1958
Publication numberUS 3054438 A, US 3054438A, US-A-3054438, US3054438 A, US3054438A
InventorsHans Lindemann, Udo Wegner
Original AssigneeTh Calow & Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pipe straightening machine
US 3054438 A
Abstract  available in
Images(2)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

U. WEGNER ETAL.

PIPE STRAIGHTENING MACHINE Sept. 18, 1962 2 Sheets-Sheet 1 Filed Dec. 2, 1958 ion/EH: RS U70 was-MEX.

HHNS LINPEHWNN P 18, 1952 u. WEGNER ETAL. 3,054,438

PIPE STRAIGHTENING MACHINE Filed Dec. 2, 1958 2 Sheets-Sheet 2 iwawoks uPo WEGNEK. HH'NS LINyEMPrNN Patented Sept. 18, 1962 3,054,438 PIPE STRAIGHTENING NAC Udo Wegner, Heidelberg, and Hans Lindemann, B elefeld, Germany, assignors to Th. (Ialow & (30., Bielefeld, Germany, a firm of Germany Filed Dec. 2, 1958, Ser. No. 777,708 Claims. (Cl. 153-32) The present invention relates to a straightening machine, particularly for straightening tubes and pipes which have a relatively large diameter as compared with the wall thickness thereof.

Although the known straightening machines are well adapted for straightening gas and boiler pipes or the like of the conventional commercial diameters, that is, pipes of a diameter of from 10 to 150 mm. with wall thicknesses of 1 to 8 mm. in accordance with the respective diameter, it is found that pipes and tubes of a relatively large diameter of, for example, 500 mm. and a wall thickness of, for example, only 8 mm., are easily distorted by bulges at those points where the straightening rollers are staggered relative to each other. This applies, for example, to a machine of a design as disclosed by the German Patent No. 538,338. Even though such bulges are often not apparent to the eye, they are usually suflicient to increase or even to cause deformations of the pipe, for example, when such pipe is embedded in the ground.

It is therefore an object of the present invention to provide a machine for straightening pipes and tubes which have a relatively small wall thickness as compared to the large outer diameter thereof and which insures that the straightening operation will not result in any deformations or bulges in the pipes.

Some of the known straightening machines including the machine disclosed in the above-mentioned German patent are provided with straightening rollers which are staggered relative to each other along the periphery of the workpiece as seen in the longitudinal direction thereof. These straightening rollers are adjustably mounted in a revolving frame. In another type of such machines, as disclosed by the U. S. Patent No. 2,411,395, the straightening rollers are mounted in a stationary position and adjustable within several planes extending transverse to the axis of the pipe, and each of these planes contains an even number of straightening rollers, namely four. Although there have also been other straightening machines with a revolving frame and three straightening rollers within one plane, they could only be used for straightening pipes of a relatively small diameter and a great wall thickness since when used for straightening pipes of a relatively great diameter and small wall thickness, they produced bulges in the pipes.

The straightening machine according to the present invention is similar to some of the known machines, as described above, insofar as it also comprises a revolving frame in which hyperbolically shaped straightening rollers are mounted which are adjustable about radial axes and are staggered relative to each other in the axial direction of the pipe, and between which rollers the pipe is passed nonrotatably by means of feed and withdrawing rollers.

In comparison to these prior machines it is, however, an important feature of the present invention to arrange and adjust the straightening rollers so that, when the machine is not in operation but at a standstill, any generatrix of the pipe wall extending parallel to the axis of the pipe intersects the line of contact of at least one straightening roller with the pipe wall.

A large number of tests carried out have shown that the tendency of the pipes to bulge locally will decrease considerably or be entirely avoided if the straightening machine is designed according to the invention, namely, by providing in each of the planes as many straightening rollers as possible. It has further been found that even the ends of the pipes will be straightened comparatively well since the individual straightening units follow each other very closely. It is therefore the essential feature of the invention that for straightening pipes and tubes of a relatively large diameter in comparison to the small wall thickness thereof, the pipe to be straightened cannot change its circular cross sectional shape at the points where it is acted upon by the straightening rollers. The provision of several straightening rollers surrounding a pipe within the same plane practically corresponds to an arrangement of circular disks within the pipe which would similarly increase the stability of the pipe against bulging. It would therefore also be possible to provide the pipe to be straightened at the inside thereof with suitable disks or the like which are adjustable to the respective diameter of the pipe and remain therein while the pipe is being passed through the straightening machine. However, such means for preventing the bulging of the pipe during the straightening process require a considerably greater efiort and expenditure than the means according to the present invention because of the difliculty involved in securing the necessary parts at the inside of the pipe. It has further been found that, when providing a plurality of straightening rollers within each of several planes extending transverse to the axis of the pipe and spaced from each other, an uneven number of straightening rollers should be provided within each of these planes. Furthermore, the same number of straightening rollers should be provided within each transverse plane, and those in one plane should be staggered relative to those in an adjacent plane.

These and further objects, features, and advantages of the present invention will become more apparent from the following detailed description thereof, particularly when read with reference to the accompanying drawings, in which FIGURE 1 shows a longitudinal section of a straightening machine according to the invention including feed and withdrawing rollers and a revolving frame with adjustable straightening rollers intermediate the former rollers;

FIGURE 2 shows an end view of the feed rollers of the machine according to FIGURE 1;

FIGURE 3 shows a cross section taken along line AA of FIGURE 1 of a revolving frame with five straightening rollers disposed within a plane extending vertically to the axis of rotation of the frame; while FIGURE 4 shows a cross section similar to that according to FIGURE 3 but showing a revolving frame with nine straightening rollers disposed Within the same plane.

As shown in FIGURE 1 of the drawings, the known straightening machines of the type as described above usually consisted of a revolving frame 4 which was rotatably mounted in bearings 1 and 2 and driven by a gear 3 or the like. This revolving frame 4 contained, for example, five hyperbolically curved straightening rollers 6, 7, 8, 9, and 10 which were mounted so as to be adjustable about the radial axes 11, 12, 13, 14, and 15, respectively. These axes 11 to 15 were therefore disposed within parallel planes which extend at equal or unequal distancees from each other in a direction vertical to the axis of rotation of frame 4.

If a pipe 16 was to be straightened, it was passed through frame 4 in the direction as shown by the arrow 17. The feed rollers 18 and 19 then fed pipe 16 forwardly and between straightening rollers 11 to 15, while rollers 20 and 21 withdrew the pipe from the machine.

With an arrangement of the straightening rollers as above described, a bulging of the pipe walls could not large outer diameter and a relatively small wall thickness. According to the present invention, however, as shown I particularly in'FIGURES 3 and 4, each of the straightening rollers 6 to 10 as previously applied is now associated with additional straightening rollers 6 to 10in such a manner that all of the rollers which are disposed within the same plane surround the pipe 16 as completely as possible so that it is practically impossible that, while the pipe is being straightened, its circular cross-sectional shape will become distorted. The number of straightening rollers to be applied within each plane transverse to the axis of the pipe depends upon the diameter of the pipe to be straightened. Thus, while with a pipe 16 of a diameter as illustrated in FIGURE 3 five straightening rollers will cover almost the entire peripheral surface of the pipe, a pipe 16 of a larger diameter, as illustrated in FIGURE 4, will require, for example, nine straightening rollers within each plane.

The peripheral contour of the straightening rollers is preferably designed so that the latter will have a linear engagement with the pipe to be straightened. The particular manner of mounting and adjusting the straightening rollers does not form a part of the subject matter of the present invention and different means may be used for that purpose. Thus, for example, each group of straightening rollers 6 to 10 may be adjusted by itself or all of them may be adjusted together to the desired diameter, or each straightening roller may be made adjustable individually.

perbolic surfaces and being rotatably mounted on said frame, said sets of straightening rollers being located in planes extending at an angle-to said axis, the straighten- The distinguishing characteristic of the invention thus 7 consists in mounting a plurality of straightening rollers within a revolving frame so as to be disposed either within a plurality of parallel planes transverse to the axis of the pipe ortube to be straightened or at any event within a plurality of parallel planes extending at an angle to the axis of the pipe, and so that each plane transverse or inclined to the axis of the pipe contains such a number of straightening rollers that, except for small spaces between the rollers in each plane to allow for their unrestricted movement, the entire peripheral surface of the pipe to be straightened will be enclosed by and in engagement with the straightening rollers. 'Expressed in dif ferent words, the straightening rollers are disposed along the pipe or tube to be straightened so that, when the machine is at a standstill, any generatrix of the pipe wall extending parallel to the axis of the pipe will intersect ing rollers of each set being'spaced about said axis and about the peripheral cylindrical surface of the pipe, each straightening roller having a line of engagement with the cylindrical peripheral surface of the. pipe, said rollers being'spaced about the peripheral surface of said pipe in such a manner that any plane through said axis intersects the line of engagement of at least one roller in each set.

2. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each'other about said axis; and a plurality of sets of straightening rollers having hyperbolic surfaces and being rotatably mounted on said frame, said sets of straightening rollers being located in parallel planes extending at the same angle to said axis, the straightening rollers of each set being spaced about said axis and about the peripheral cylindrical surface of the pipe, each straightening roller having a line of engagement with the cylindrical peripheral surface of the pipe, said rollers being spaced about the peripheral surface of said pipe in such a manner that any plane through said axis intersects the line of engagement of at least one roller in each set. V t

3. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feedinga cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; and a plurality of sets of straightening rollers having hyperbolic surfaces and being rotatably mounted on said frame, said sets of straightening rollers being located in planes extending at an angle to said axis, the straightening rollers of each set being uniformly spaced about said axis and about the peripheral cylindrical surface of the pipe, each straightening roller having a line of engagement with the cylindrical peripheral surface of the pipe, the straightening rollers of each set being staggered in circumferential direction relative to the straightening rollers in the at least one line of engagement of a straightening roller. 7

cally around the pipe and thus form helical generatrixes along the Wall of the pipe, each of which has a width cor-' responding to the width of the individual straightening rollers.

Although our invention has been illustrated and described with reference to the preferred embodiments tthereof, we wish to have it understood that it is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed our invention, what we claim is:

1. In a'machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means. in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; and a plurality of sets of straightening rollers having hyadjacent sets of straightening rollers, said lines of engagement of said staggered rollers in said sets forming interrupted helical lines on the cylindrical surface of the pipe, said rollers being spaced about the peripheral surface of said pipe in such a manner that any plane through said axis intersects the line of engagement of at least one roller in each set, the projections of said lines of said straightening rollers onto a plane perpendicular to said axis forming a complete circle so that all lines on said cylindrical peripheral surface of the pipe extending parallel to said axis intersect with the line of engagement of at least one straightening roller.

4. In a machine for' straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; a plurality of sets of straightening rollers having hyperbolic surfaces and being'rotatably mounted on said frame, said sets of straightening rollers beinglocated on planes extending at an angle to'said axis,'each set of straightening rollers having an uneven number of straightening rollers spaced about said axis and about the peripheral cylindrical surface of the. pipe, each straightening roller having a line of engagement with the cylindrical peripheral surface of the pipe, said rollers being spaced about the peripheral surface of said pipe in such a manner that any plane through said axis intersects the line of engagement of at least one roller in each set, the projections of said lines of engagement of said straightening rollers onto a plane perpendicular to said axis forming a complete circle so that all lines on said cylindrical peripheral surface of the pipe extending parallel to said axis intersect with the line of engagement of at least one straightening roller.

5. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; a plurality of sets of straightening rollers having hyperbolic surfaces and being rotatably mounted on said frame, said sets of straightening rollers being located in parallel planes extending at the same angle to said axis, each set of straightening rollers having an uneven number of straightening rollers uniformly spaced about said axis and about the peripheral cylindrical surface of the pipe, each straightening roller having a line of engagement With the cylindrical peripheral surface of the pipe, said rollers being spaced about the perpheral surface of said pipe in such a manner that any plane through said axis intersects the line of engagement of at least one roller in each set, the projections of said lines of engagement of each set of straightening rollers onto a plane perpendicular to said axis forming substantially a complete circle so that all lines on said cylindrical peripheral surface of the pipe extending parallel to said axis intersect With the line of engagement of more than one straightening roller.

6. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; and a plurality of sets of straightening rollers having hyperbolic surfaces and being rotatably mounted on said frame means, said sets of straightening rollers being substantially located in planes extending at an angle to said axis, each set of straightening rollers having an uneven number of straightening rollers uniformly spaced about said axis and about the peripheral cylindrical surface of the pipe, each straightening roller having a line of engagement with the cylindrical peripheral surface of the pipe and said lines of engagement in each set of straightening rollers substantially enclosing the peripheral surface of the pipe, said rollers being spaced about the peripheral surface of said pipe in such a manner that any plane through said axis intersects the line of engagement of at least one roller in each set, and the straightening rollers of each set being staggered in circumferential direction relative to the straightening rollers in the adjacent sets of straightening rollers so that all lines on said cylindrical peripheral surface of the pipe extending parallel to said axis intersect at any instant With the line of engagement of at least one straightening roller.

7. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; and a plurality of sets of straightening rollers mounted spaced from each other in direction of said axis on said frame means, each of said straightening rollers being rotatably mounted on said frame means and having a hyperbolic surface having a line of engagement with the peripheral surface of said pipe, the straightening rollers in each set being spaced about the peripheral surface of the pipe so that any plane through said axis intersects the line of engagement of at least one roller in each set and the projections of said lines of engagement of said straightening rollers onto a plane perpendicular to said axis forming a complete circle so that all lines on said cylindrical surface of the pipe extending parallel 6 to said axis intersect With the line of engagement of at least one straightening roller.

8. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; and a plurality of sets of straightening rollers, each composed of an uneven number of rollers and mounted spaced from each other in direction of said axis, on said frame means, each of said straightening rollers being rotatably mounted on said frame means and having a hyperbolic surface having a line of engagement with the peripheral surface of said pipe, the straightening rollers in each set being spaced about the peripheral surface of the pipe so that any plane through said axis intersects the line of engagement of at least one roller in each set and the projections of said lines of engagement of said straightening rollers onto a plane perpendicular to said axis forming a complete circle so that all lines on said cylindrical surface of the pipe extending parallel to said axis intersect with the line of engagement of at least one straightening roller.

9. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; and a plurality of straightening rollers mounted spaced from each other in direction of said axis on said frame means, the rollers in each set of rollers being offset with respect to the rollers in the set adjacent thereto, each of said straightening rollers being rotatably mounted on said frame means and having a hyperbolic surface having a line of engagement with the peripheral surface of said pipe, the straightening rollers in each set being spaced about the peripheral surface of the pipe so that any plane through said axis intersects the line of engagement of at least one roller in each set and the projections of said lines of engagement of said straightening rollers onto a. plane perpendicular to said axis forming a complete circle so that all lines on said cylindrical surface of the pipe extending parallel to said axis intersect with the line of engagement of at least one straightening roller.

10. In a machine for straightening cylindrical pipes, in combination, frame means; feeding means for feeding a cylindrical pipe having an axis through said frame means in direction of said axis; means for rotating said frame means and said pipe relative to each other about said axis; and a plurality of sets of straightening rollers mounted spaced from each other in the direction of said axis and on said frame means, each of said straightening rollers being rotatably mounted on said frame means and having a hyperbolic surface having a line of engagement With the peripheral surface of said pipe, the straightening rollers in each set being disposed about the peripheral surface of the pipe in a such a manner that any plane through said axis intersects the line of engagement of at least one roller in each set.

References Cited in the file of this patent UNITED STATES PATENTS 299,615 Borchardt June 3, 1884 456,883 Brightman July 28, 1891 613,754 Brightman Nov. 8, 1898 1,326,981 Soderlund Jan. 6, 1920 1,859,851 Stiefel May 24, 1932 FOREIGN PATENTS 452,124 Italy Oct. 10, 1949

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US299615 *Jun 3, 1884 Wire-straightener
US456883 *Feb 6, 1891Jul 28, 1891 brightman
US613754 *Nov 20, 1896Nov 8, 1898 Shaft-straightening machine
US1326981 *Jun 7, 1918Jan 6, 1920Lidkopings Mek Verkst AbMethod and machine for straightening of metal wire
US1859851 *Aug 3, 1931May 24, 1932Stiefel Ralph CStraightening machine
IT452124B * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3176496 *Dec 11, 1962Apr 6, 1965Mannesmann Meer AgMetal forming process and apparatus
US4825674 *Jan 15, 1988May 2, 1989Sumitomo Metal Industries, Ltd.Metallic tubular structure having improved collapse strength and method of producing the same
US6490900 *Oct 11, 2000Dec 10, 2002American Cast Iron Pipe CompanyPipe gauging and rounding apparatus and method
Classifications
U.S. Classification72/98, 72/100
International ClassificationB21D3/06, B21D3/00
Cooperative ClassificationB21D3/06
European ClassificationB21D3/06