US2071154A - Method of and apparatus for pipe finishing - Google Patents

Description

1 I Feb. 16, 1937. J. ADAMS, JR 2,071,154

METHOD OF AND APPARATUS FOR PIPE FINISHING Filed July 20, 1935 6 Sheets-Sheet 1 gl 1 INVENTOR g in I JQWZ W W0 i i aw/flj 2 Feb. 16, 1937. J. L. ADAMS. JR

METHOD OF AND APPARATUS FOR PIPE FINISHING Filed July 20, 1933 6 Sheets-Sheet 2 Feb. 16, 1937. J. L. ADAMS. JR 2,071,154

METHOD OF AND APPARATUS FOR PIPE FINISHING Filed Ju1 2o, 1933 s sheets sheet s INVENTOR Feb. 16, 1937. J. ADAMS. JR

METHOD OF AND APPARATUS FOR PIPE FINISHING Filed July 20, 1933 6 Sheets-Sheet 4 ":ENTOR y. at??? M24 1/ g, 4

Feb. 16, 1937. J. 1.. ADAMS. JR

I METHOD OF AND APPARATUS FOR PIPE FINISHING Filed July 20, 1933 6 Sheets-Sheet 5 R O T N E V m Feb. 1 6, 1937.

J. L. ADAMS, JR

METHOD OF AND APPARATUS FOR PIPE FINISHING Filed July 20, 1935 6 Sheets-Sheet 6 IBIZENTOR FM Patented Feb. "16, 1931 UNITED STATES METHOD OF AND FINISHING James L. Adams, Jr Youngstown, Ohio, assignor to The Youngstown Sheet a Tube Company, Youngstown, Ohio, a corporation of Ohio Application July 20. 19st, sci-a m. 081,391 i My invention relates to the finishing of -metallic articles produced in long lengths and, in particular, to the sizing and straightening of pipe, although the invention is not limited particular application.

' It is known in the art of makingmetailic ariicles of considerable length, such as pipe, that the productmust be subjected to a finishing operation for the purpose of bringing it precisely to the desired finished size and to straighten it so that any bends or cambers introduced during the manufacture will not appear in the finished product. tofore in the finishing of pipe, for example, -to pass the pipe while hot through reeler rolls. Cold rolling through cross roll machines has also been employed, as well as a press, for the purpose of straightening bent pipe. Reeler rolls are objectionable because they mark the pipe-and tend to impart an elliptical section thereto.

' Cross rolls are not entirely satisfactory because they cannot conveniently be made strong enough to handle heavy wall pipe cold, and the feed therethrough must be relatively slow, so that such machines have a low output tonnage per diem. Inaccurate straightening, especially near the ends of the pipe, results. The press is objectionable because it is slow, indefinite, and laborious, and is a cut and try method, often requiring two or three repeat operations at 90 to each other to get the requisite straightening, as actual trial has shown.

I have, however, invented a method and apparatus for precision straightening and sizing metal lengths, such as cold, hea'vy pipe, continuously, and at high speed. In accordance with my invention, I simultaneously crush to size and straighten the pipe. The compression is effected by suitable, heavy rolls and the straightening by accurately aligning the pipe in a plurality of roll stands simultaneously with and on each side of the crushing position. i

In the straightening operation, I find it advantageous sometimes to rotate at least one of the roll stands bodily about the axis of the pipe in a plane perpendicular thereto. This rotation is unnecessary for low carbon steel tubes, however, and even for high carbon steels is preferably such as to only deflect a straight pipe to, but not beyond, its surface fiber elastic limit. Thus a pipe which is straight initially will not be bent,

but a pipe which is initially cambered will be bent beyond its surface fiber elastic limit in the precise direction necessary to straighten it. This straightenin op ration is facil ated i t pip is It has been the practice heresimultaneously being subjected to high compression or crushing tosize. This follows from the fact that the crushing causes some considerable molecular flow .which momentarily. vastly increases .the susceptibility of the product to 5 straightening. The material takes a permanent set as it progressively passes the crushing zone and if rigidly held straight as it enters and leaves the crushing roll stand, the finished product is found to be free from all camber, as has been 10 amply demonstrated by long continued, commercial tests. In accordance with my invention, I provide a plurality. -ofroll stands for simultaneously engaging a pipe. The number and arrangement 15 of the roll stands may vary but it is preferable to employ at least four or five roll stands. The rolls should be driven preferably and should be adjustable for precision alignment andfor pipe diameter. One stand of rolls may be made ro- 2 tatable about the axis of the pipe being straightened, in order to be able to straighten high carbon steel tubes, and I mount such roll stand in a pair of slightly eccentric rings and provide means for driving the rings to rotate the roll 5 stand. I also provide means for adjusting the throw of the eccentrics between zero and a certain maximum, whereby the degree of eccentricity may be accurately controlled.

For a complete understanding of the invention, 30 reference is made to the accompanying drawings illustrating several possible embodiments of the invention. The method of my invention will be explained in the course of the description of the apparatus by which it is carried out. In the 35 drawings:

Figure 1 is a side elevation of one formof the invention in which the rotatable stand has nondriven rolls;

Figure 2 is an end elevation of a similar, driven 40 roll type, rotatable stand looking from theleft as seen from the line 11-11 in Figure 1:

Figure 3 isa partial end elevation to enlarged scale; 45

Figure 4 is a sectional view partly broken away, with parts omitted for the sake of clearness, substantially along the line .IVIV of Figure 2;

Figure 5 is a view similar to Figure 1 show- 50 ing a modified form of the invention;

Figure 6 is an end view thereof;

Figure 7 is a side elevation of a further modifled form; I I

Figure 8 is an end view thereof; and

a central rings 29.

Figure 9 is a sectional view along the line IX-IX of Figure 8.

Referring now in detail to the drawings and, for the present, to Figures 1 through 4 particularly, pipe finishing apparatus in accordance with my invention includes a base I!) resting on cross rails ll. Sizing and straightening roll stands I 2,]!3, l4, and A are mounted on the base I 0. The'stands I2 and I3 are similar and the. latter at least is provided with sizing rolls, while the stand I4 is provided with straightening rolls mounted either for rotation about the axis of the tube being straightened, which is indicated in Figure l at 15, or for stationary positioning in accurate alignment with tube axis. The roll stands I2 and I3 are made very stiff or rigid, but otherwise of more or less conventional design, and such description as they require will be given as an incident to the description of the other parts of the apparatus. Since the principal constructional novelty resides in the straightening stand II, the detailed description thereof will be emphasized more particularly. The roll stand l4 comprises a pair of opposed, flanged plates l6 and I1 secured to the base I and tied together adjacent their upper ends by bolts l8. Spacers l9 and 20 tie the tops of the stands I2 and 13 together and to the top of the plate l1. are provided with circular windows in which bearing raceways 2| are seated. Rings 22 are rotatably seated by means of ball bearings 23 in the raceways 2|. The rings 22 have outwardly extending flanges 24 which are provided with gear teeth 25. I

The rings 22 have circular windows therein eccentric to the axes of the windows in the plates l6 and I1. Rings 26 are rotatably seated in the eccentric windows in the rings 22. The rings 26 have outwardly projecting flanges 21 which are internally toothed as at 28. Central rings 28 are rotatably seated in eccentric openings in the rings 26 on ball bearings 38.

A roll housing frame 3| is supported on the The frame is rectangular in outline, as shown in Figure 2, and is substantially U-shaped in section, as shown in Figure. 4. The frame 3| has bearing blocks 32 (Fig. 2) disposed in the window thereof for providing bearings for the shafts of straightening rolls- 33.

The straightening rolls may be geared together by bevel teeth on the lateral faces thereof, and driven by means of the through shaft A, by any convenient propelling means, if so desired.

- In this case the eccentric adjustment would normally be placed on the opposite side of the l2 and I3 are similar in general to the frame 3| of the housing 14 except that the housings l2 and I3 are stationary and not movable as is the housing 3|, in a manner to be described later. The rolls of the stands l2 and I3 are driven while the rolls 33 of the stand l4 may be idler rolls, although they are preferably. geared together for simultaneous rotation, and driven by, shaft A, as noted.

The drive for the rolls of the stands l2 and I3, and M, if desired, includes a motor 34 mounted on the base In disposed laterally of the path of travel of the pipe IS. A pinion on the motor shaft engages a gear 35 carried on a back shaft 36 on the motor. The shaft 36 is coupled to a shaft 31 extending alongside the 19.1 fie ds,

The plates l6and l1 l2, l3 and I4. Gear housings 38 on the stands l2 and I3 enclose worm Wheels 38 which mesh with worms 40 on the shaft. 31. The worm wheels 39 are keyed to shafts 4| which drive one of the rolls 33 of the stands l2 and I3.

The shaft 31 also extends through bearings 42 (Fig. 4) on the frames 16 and I1 of the housing l4. 7

A shaft 43.journaled in bearings 44 (Fig. 4) extending from the frame 3| is provided with pinions 45 meshing with the internal teeth 28 on theflanges 21 of the rings 26.

A stationary auxiliary shaft 46 is suspended by links 41 from the outside of bearing bushing 44 carrying the shaft 43. Long hubbed pinions 48 running freely on the shaft 46 mesh with pinions 49 on the shaft 43.

A secondary stationary auxiliary shaft is similarly supported by links 5| from the bearing bushing 42 carrying shaft 31. Links 52 connect the shafts 46 and 50. In actual practice links 41 and 52 may be united in one, as shafts 43, 46, and 50 are in a straight line anyway. This link system also prevents any continued rotation of stand l4 as a whole, about the pipe as an axis. Pinions 53 and 54 on the shaft 50 mesh with thepinions 48 on the shaft 48 and are adapted to be engaged by pinions 55 and 56, respectively, which are keyed to the shaft 31. A gear-shifting lever 51 permits either of the pinions 55 and 56 to be moved into engagement with its cooperating pinion, the two shifting pinions 55 and 56 being attached together by any convenient means, so as to slide as one unit.

. It will be apparent that the linkages 41, 5| and It will be observed that the pinion 55 is slightly smaller. in diameter than the pinion 56 so as to give about one less tooth. Pinions 53 and 54 are reversely dimensioned. The size of the meshing pinions is such that when the gear shift lever 511s thrown to the left to cause the pinion 55 to mesh with the pinion 53, the shaft 31 will drive the rings 26 at a speed very slightly different from that at which the rings 24 are driven. The shaft 31, of course drives the rings 24 directly through the pinions 58. It also drives the rings 26 indirectly through the pinions 55, 53, 48, 49, and 45.

Rotation of the rings 22 and 26 at very slightly different speeds for a few seconds only, will cause a change in the eccentricity of the central rings 23 relative to the windows in the plates l6 and I 1. When the desired degree of eccentricity has been attained, as may be determined by suitable index markings, the adjustment is terminated by restoring the shift lever 51 to central position. As already explained, it is one object of the invention to provide a roll stand, the rolls of which may, if desired, be made to rotate or gyrate circularly about the axis of the pipe being straightened. By the operation just described, the frame 3l of the roll stand l4 can be adjusted to the desired degree of eccentricitywith respect to the axis of the pipe l5. Once properly adjusted, the frame 3| may now be rotated continuously through a path determined by the eccentricity of the central rings 28 relative to the windows in theplates l8 and I1, by shifting the lever 51 to the right so that the pinion 88 will mesh with the pinion 84. The dimensions of the pinion 88 and its cooperating pinions are such that the rings 22 and 28 will be driven at the same speed. There is thus no further variation in the eccentricity of the central rings 28 as aresult of this rotation, but the whole frame 8| of the roll 1 stand gyrates slowly and circularly about the axis of the pipe being straightened, or with a suitable compensatory adjustment of.the rings 22 and 28, the eccentricity can be cancelled out completely, if desired, as in the case of low car- 5 bon steel pipes, where the gyration is found to be unnecessary.

In using the apparatus described above to practies the method of my invention, I adjust the eccentricity of the rings 22 and 28 to the desired low value and then advance the pipe to be straightened through the crushing stands I! and i8, the straightening stand it and the final guiding stand A. The rolls of the crushing stands reduce the pipe to the required cross sectional 0 dimensions and shape, and at the same time hold the pipe firmly. The straightening stand 3| gyratingand continuously effects a straightening of the pipe by effecting a progressive permanent set in the metal thereof while the latter is in a 0 condition of molecular flow facilitated by the crushing rolls.

Figures 5 and 6 illustrate a modified form of the invention which is actually the preferred form. In this form, the apparatus comprises a base 88, stationary crushing stands 8| and 62 and a mating straightening stand 83. In addition, I provide secondary straightening or guiding stands 84 and 85. The drive for the stands 8| and 82 and for'the oscillation of the stands 10 88 is effected through a shaft 88 similar to the shaft 81 of the modification already described. Corresponding elements are indicated by the same reference numerals. The construction of the stand 88 is substantially identical with that of the stand ll of Figure 1.

Each of the cmshing stands 8i and 82 of Figure 5 comprises a housing 81 (Fig. 6) having crushing rolls 88 journaled therein. Lateral faces of these rolls have meshing gear teeth formed'there- 0 on and the drive therefor extends from the shaft 68 through a worm 88 thereon, a worm wheel I8, a shaft II and a bevel pinion 12. The worm wheels I8 are enclosed in housings 18. The size of the roll pass may be adjusted by means of a hand wheel 14 in accordance with the invention disclosed in my co-pending application Serial No. 453,888, filed May 20, 1930, for Welding apparatus and method of welding, the adjustment of the rolls being always indicated by a dial and pointer 15.

The construction of the stands 88 and of Figure 5 is also further shown in Figure 6. A

rectangular frame I8 which is preferably split on its top side, is mounted on a base 11 and is provided with rolls l8 journaled in bearing blocks I8 carried by the frame. An adjusting screw 88 having its ends oppositely threaded engages lugs 8| extending upwardly from the split top of the frame. The frame maybe sprung to a limited degree by turning the screw and a corresponding adjustment of the roll pass effected.

Lock nuts 82 hold the screw in adjusted position, while the thrust block 82A centers said screw on the housing 81.

The function of the secondary guiding and and 88 are fixed to the base 85.

' accurately over a greater length, on each sideof the crushing position.

Figures 7 and 8 illustrate a further modification of the invention which is similar in general to that shown in Figures 5 and 6 but differs therefrom in some details. As shown in Figures '1 and 8, a base 85 is provided with a straightening stand 88 similar to those shown at 88 and i4,

crushing stands 81 and 88 on opposite sides thereof, and guide stands 88 and 88. The oscillatable straightening stand 86 is driven through a shaft 8| No drive for the rolls of the crushing stands 81, 88, or the guide stands 88, 88, is shown although such would always be provided as the crushing stands 81 The-guide stands 88- and 88 are adjustable therealong by adjusting screws 92. This permits the spacing of the guide stands to be varied so that the length of the pipe over which it is rigidly gripped and positioned by the stands may be varied.

preferred construction. The

The construction of the crushing and guide roll stands 88 and" will be understood from Figure 8. These stands are somewhat alike, differing principally in size and strength. The stand 88 comprises a rectangular frame 83 with rolls 94 journaled therein in bearing blocks 85. The corners of the frame 88 are reinforced by a plurality of gusset plates 88 welded therein, the plates being of graduated width to provide clearance for the rolls.

.The crushing stand 88 is quite similar in detail to the guiding stand 88 and further showing and description thereof are believedto be unnecessary. Possible means for roll adjustment have already been described. The general principle of operation of my invention is as follows: If a long 20" pipe, for example, be firmly fixed in a concrete block at one end, so that it is immovable, and a moderate transverse stress applied to the other end, the pipe may be flexed slightly by the latter stress, but it will not be permanently bent thereby.

If, however, some hydraulic or other-means be now provided to crush the tube to a very slightly smaller diameter near its point of support, while the above side stress is still maintained, then it will be found on removal of the crushing force, that the above very small side stress has produced apermanent set in the tube in its own direction.

And if this crushing operation be made progressite along the pipe, and the small side stress be produced progressively in all transverse directions. as by a weaving motion around the centre of the pipe to a very slight 'extent, then the pipe will come. through straight, as well as precisely sized and circularized at the same time. No previous method of operation has accomplished these three desirable ends at the'same time, to

the same extent as is readily accompl shed by the apparatus of my invention, or to anything like the same speed. A

In the case of low-carbon steel tubes, simply holding the tube straight for a sufilcient distance, as it passes throughseveral tandem situated accurate guide stands of suflicient rigidity of structure, introduces sufficient side stresses due to this forced holding straight thereof, to give the desired straight set to the progressively crushed tube, without any weaving or gyration of the straightening stand, as has been amply proved by several months of commercial operation of a large straightening unit.

It will be apparent from the foregoing description that the invention provides a highly desirable method and apparatus for straightening and sizing or finishing pipe at high speed. The apparatus employed is comparatively simple and may easily be constructed to provide the required strength and rigidity, the latter being an important element in pipe straightening operations. It will be obvious that known devices will be used for supplying pipe to the apparatus and receiving it therefrom. Instead of driving the crushing rolls, external means might be employed for advancing the pipe through the straightening apparatus. The opposed eccentric rings permit the degree of eccentricity of the straightening roll stand to be accurately determined and maintained, when such eccentricity is required. For this purpose, a suitable pointer and index scale on the two rings, respectively, will be of assistance.

The principal advantages of the invention are that it permits pipe to be finished with precision at high speeds, giving accurate circularity, perimeter, and straightness from end to end, and it leaves the pipe with a perfectly smooth exterior. These advantages do not characterize the methods and apparatus of the prior art recited at the beginning of this specification. The straightening is very much better than that produced by a hydraulic press, when operating on say 50 feet.

lengths of 24" or 26.'-heavy-wall pipe, for example, and the speed about ten times that of the latter. Other advantages are found in the ease with which the apparatus maybe maintained and the rolls re-ground to compensate for the inevitable wear. The apparatus is less costly than those of the prior art and its energy requirements are also much less. It'is' particularly applicable to tubes.

Although I have illustrated and described herein 'but a few modifications .of the invention, it will be apparent that-many changes therein may be made without departing from the spirit thereof or the scope of the appended claims I claim:

1. In a method of straightening a pipe, the.

steps including exerting a crushing transverse pressure on a short portion of the length thereof progressively, and simultaneously causing gyration of an adjacent portion of the pipe about its own axis.

2. In a continuous pipe finishing machine, a shaping roll stand effective to exert a crushing action on a short portion of the length of the pipe progressively and to cause fiow of the metal in such portion, and cooperating means for simultaneously straightening the pipe progressively as it passes said stand, said means including other roll stands, said shaping stand being mounted for gyration in a circular path about the pipe axis.

3. Progressive pipe finishing apparatus comprising three alined roll stands operative in tandem, each stand including a plurality of rolls Journaled substantially in a common plane transverse to the pipe axis, the rolls of said stands providing'working passes of substantially the same contour, the pass of the middle stand being adjusted to a smaller diameter than that of 4. The apparatus defined by claim 3 characterized by means for adjusting the radius of gyration of said intermediate roll stand.

5. In a. straightening roll stand, a supporting frame, a ring thereon having an eccentric opening, a disc rotatably seated in the opening, a roll housing supported on said disc, means for driving said ring and disc temporarily at slightly different speeds for adjusting the eccentricity of said housing, and means for driving the ring and disc at the same speed to cause gyration of the housing about a fixed axis.

6. In a straightening apparatus, a supporting frame, rings journaled therein having gear teeth formed thereon, eccentric openings in the rings, discs rotatably seated in said openings, a roll housing supported on the discs, means for driving said rings and discs at the same speeds for causing gyration of the roll housing, or at different speeds for adjusting the eccentricity of its gyration. v

7. In a method of straightening a hollow, tubular article, the steps including moving the article axially, gripping the article at a plurality of spaced alined points along its length, and throughout substantially its entire periphery at said points, maintaining the portions of the article at said points in alinement, and progressively crushing the article from end to end, without substantially elongating it.

8. Apparatus for straightening metal lengths, comprising entering and exit guide roll stands, fixed sizing and shaping roll stands therebetween, and a straightening roll stand between the sizing and shaping roll stands, the straightening roll stand including a frame member, a ring having an eccentric opening rotatable in said member, and a disc rotatable in said ring, a roll housing supported on said disc, and means for rotating the ring to cause gyration of said housing about the axis of the other roll stands.

9. In a method of straightening pipe, the steps including passing it axially through a crushing zone, exerting transverse crushing pressure radially of the pipe in said zone progressively along the pipe length without materially elongating the pipe, and simultaneously maintaining an adjacent portion of the pipe in accurate axial alignment with the portion subject to crushing pressure.

10. In a method of finishing pipe, the steps including continuously passing it axially through a crushing zone, applying crushing force radially of the pipe in said zone and progressively along the pipe length without materially elongating the pipe, and maintaining an adjacent portion of the pipe in precision alignment.

11. In a straightening roll stand, a frame, a window therein, a member rotatably disposed on said frame in overlying relation to said window, said member having an eccentric opening therein, a roll housing carried on said member in line with said opening, and means for rotating the member to effect gyration of the housing.

12. In a method of straightening, sizing, and circularizing an elongated hollow tubular article, the steps comprising continuously moving the article axially, progressively gripping the article around substantially its entire periphery at a plurality of longitudinally spaced positions therealong, similarly gripping said article at another plurality of spaced positions therealong, maintaining all these gripping positions in precision alignment, and exerting a crushing force around substantially the entire periphery of said article and progressively along the length thereof at a point intermediate the two sets of gripping positions above mentioned without substantially elongating the article.

13. In a method of finishing pipe, the steps including exerting a transverse crushing pressure progressively on a narrow zone of the pipe without materially elongating it, while causing relative axial movement between the pipe and said zone, and maintaining alignment of adjacent portions of said pipe.

14. The method defined by claim 13 characterized by maintaining in alignment with said zone, the portions of the pipe on both sides thereof.

15. The method defined by claim 13 characterized by maintaining alignment of a plurality of spaced portions of the pipe lying on the same side of said crushing zone.

16. In a method of straightening a hollow, tubular article, the steps including progressively advancing the article axially while gripping the article substantially around its periphery at a plurality of zones spaced longitudinally of said article, without exceeding the elastic limit, maintaining said zones in accurate alignment, and exerting a crushing pressure beyond the elastic limit substantially around the entire periphery elongating it.

1'7. The method defined by claim 16 characterized by imparting gyr'atory motion to said crushing zone.

. 18. A straightening r011 stand comprising a stationary supporting frame having a window opening therein, a ring rotatably positioned in said opening and supported by said frame, the interior edge of said ring being eccentric to the exterior edge, a roll housing mounted within and supported by said ring, and means for rotating said ring to cause gyration of said housing.

JAMES L. ADAMS, JR;

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