US2357420A - Apparatus for galvanizing rods - Google Patents

Description

2 Sheets-Sheet l A. S. MOORE APPARATUS FOR GAILVANIZING RODS Filed Dec. 2, 1942 n W n 4 u I M M. n u u a w u h u THHHIIIIIIIIIIIII'IIIH'IJHHHIIH ,7. a Q m N u m m u w N u N fix X m \w I i j lm l H H if f :6 \YKNKW Q h M R w Sept. 5, 1944.

2 Sheets-Sheet 2 A LL M Sept. 5, 1944. A. s. MOORE APPARATUS FOR GALVANIZING RODS Filed Dec. 2, 1942 threads with spelter.

f Patented Sept. 5,1 1944 UNITED STATES PATENT OFFICE I Armrmc RODS.

Allen S. Moore, Lebanon, Pa., asslgnor to Bethlehem Steel Company, a corporation of Pennsylvania Application December 2. 1942, Serial No. 467,618

10 claims. (CL ill-59.4)

r of rusted threads may result in thread galling My invention relates to an apparatusfor coating uniformly rod-like or tubular objects, and more particularly it relates to an apparatus for the uniform and economical galvanizing of metal lic sucker rods.

1 Oil we1l sucker rods of the double pin and coupling type are straight steel rods, usually 25 or and imperfect shouldering of the joint. Surplus zinc in the threads will interfere with attaching couplings, so that when the threads are clogged with zinc the only way to obtain usable threads is to "bump" them, i. e., to rap or knock them against a hard surface to remove the excess spelter. This additional step means extra expense and labor and may even shorten" the life of the rod, for undue hammering may deform the thread or cause cracks that radiate out; from the point of the blow and extend for considerable depths steels employing rather costly alloying elements,

vsuch as molybdenum, chromium, manganese and nickel, which are now under war priorities and practically unobtainable. For very deep or highly corrosive wells, there is at present no satisfactory substitute for the high strength and corrosion resistance of these alloy steels, but galvanized rods of ordinary carbon steel may serve quite successfully under less extreme conditions,

provided only that the protective zinc coating is' as strongly adherent and ductile and as uniform in thickness as possible.

There are two methods of galvanizing in common use, viz., the electrogalvanizing process and the hot-dip process.- The cold coat ng applied by an electrolytic process is generally uniform, when wellapplied, and the thickness is easily regulated' by varying either the current density or the time of deposit. but the reduction in output compelled by the time factor, and the requirements of expensive electrical equipment and cur-.

rent, make this process uneconomical commercially. 4

Zinc coatings applied by the hot-dip process.

' on the other hand, are relatively free of the type on the, surface of the rod, making thecoating rough and uneven and filling the roots of the Such a coating represents an actual waste of zinc, for the durability of an unevenly applied coating is determined-by the thinnest part of the coating and not by the thickest part.

Any defect or deficiency in the zinc coating will permit quick rusting, even'before use, and very badly rusted threads can obviously destroy below the surface. A smooth, uniform coating over the threads and body of the rod is thus about the best obtainable insurance againstearly operating failure ofa string of galvanized sucker rods.

apparatus for producing a' hot-dip galvanized coating which will be, smoothly and uniformly distributed over the galvanized article.

I "Another .objectis an apparatus for procuring" more evenly and completely coated threads.

Still another object is an apparatus adapted. for covering. rod-like or tubular articles of metal with atighter and more ductile zinc coating which will not flake or crack off under stress. I

' Other and further objects will appear hereinafter in the specification and appended claims. Having thus given a general description of the advantages and objects of my invention, I shall now in order to make the same more clear, refer to, the annexed two sheets of drawings forming a part of this specification, and inwhich like characters of reference indicate likeparts.

-.Figure 1 ,is a side elevation of the apparatus of my invention, and showing its relation to the galvanizing and quenching tank; Fig. 2 is atop plan view thereof;

Fig. Sgis a, front elevation showing 'in'detail the self dju'sting guide roller device which permits the passage of the enlarged portions of the v sucker rods;

Fig. 4 is a side elevation of the guide roller device shown in Fig. 3; and

Fig. 5 is a horizontal section of a portion of the mounting of the guide roller device taken. on

all the usefulness of the rod, for the making 'up 55 cates a sucker rod, 2 one end of a'conventional galvanizing tank, which is a long shallow pan filled with molten zinc or spelter, 3 a base mounted in skewed relation at the exit end of said tank, 4 an electric motor fastened to the base,

'5 the drive shaft of the. motor, 6 a pinion on shaft5, and I an engaging gear mounted on and driving a shaft'l. Said shaft 8 drives through gears, 9,10 and II the magnetic rolls i 2 and I3 journalled in bearings l4, l5, l6 and II in end m'ountings l8 and IS. The magnetic flux which -magnetizes said rolls emanates from the magat an angle of about 45 toward the advancing sucker rod I, and mounted on fittings 25 which are preferably of brass or copper or the like to insulate from stray magnetic flux. Said fittings 25 and 26 connect through pipe 2'! equipped with valve 28 to any suitable source of heated and 39 midway between the two magnetic rolls I2 and I3 insures the proper direction and contact of the rod as it rotates and moves forward over said rolls l2 and I3.

The rotation of the rolls I2 and I3 then carries the rod I forward through the second air ring 24 up th incline ll over the rollers 43 onto conveyer trough 42. Air is blown from the air rings 23 and 24 at a pressure of 25 to 80 pounds per square inch, and is preheated to a temperature high enough to prevent too rapi cooling of the zinc. The variation of air pressur and temperature controls the thickness of the zinc I coating on the rod and can be regulated to suit compressed air (not shown) As the galvanizing tank 2 will be kept heated in the usual practice by a series of gas flames (not shown) within side burner compartment 28, the air under pressure may be heated conveniently, for example. by running the connecting pipe 21 from th compressor or other source through said gas flames, or if desired, through the molten spelter itself.

To insure the proper direction and contact of the rod l as it rotates and moves forward over the rolls l2 and I3, a guide device is provided which comprises a pair of mountings of brass or other non-magnetic metal secured by bolts 3| to the-base 3, between sald rolls l2 and I3, and having grooved slideways 32 to permit a limited amount of vertical movement to perforated blocks 33 keyed thereinto and normally held in place by vertical threaded rods 34, springs 35, and adjusting nuts 36. connected by a transverse haft 31, held in place by cotterpins 38 and having mounted thereon a grooved idle roller 39.

Adjacent thereto is the conventional elongated quenching tank 40, on which is mounted the incline 4i and pivoted conveyor trough 42, the latter being provided with a plurality of aligned idle rollers 43 like the one shown and an end stop (not shown) which may actuate an automatic kicker (also not shown) to dump the galvanized rod I into the quenching tank 40.

In the operation of my invention, any traces of rust and mill scale which may be present on the rods l are removed by pickling in a hot dilute acid solution, and washing with clean watel. Then the rods l are fluxed in a hot solution of zinc ammonium chloride, and dipped into Said blocks 33-are the molten spelter in th galvanizing tank 2.

The spelter is kept at a temperature between 790 F., and 870 F., the period of immersion therein being determined by the size of the rods and the weight of zinc coating desired, and the rods are kept from contact with the pasty zinc iron dross which collects upon the bottom of the galvanizing tank 2 by resting in a suspended cradle (not shown).

With tongs or a forked lever arrangement (not shown) the rods 1 are started one at a time by hand through the first air ring 23 until the rod l makes contact with the magnetic driven rolls [2 and I3. The self-adjusting guide roller the number of Preece dips required.

The speed of the rod carries it against a stop at the end of the conveyer trough 42, where a kicker arrangement (not shown) operated automatically or by handdischarges the rod into the water quenching tank 40.- The coating is hardened and brightened by this quenching operation. The galvanized rods are then lifted by hand from the quenching tank 40 and further processed for shipment.

The spinning of the galvanized rods in this manner results in a veryuniform coating. Rods which have not been spun show coatings of excessive thickness on their lower surfaces, due' to gravity, and thin and inadequate coatings on their upper portions. The combination of the air rings with the spinning action of the skewed rolls automatically and quickly removes excess spelter from the threaded ends, and eliminates the extra step and added labor of cleaning the threads by bumping.

An even more important advantage is that the coating produced is a great deal more adherent and ductile than any hot-dip coating for sucker rods heretofore known. Rods galvanized according to my invention have been subjected to repeated and severe tensile tests withv out the coating flaking or cracking off, and even a bend test gave only minor cracks in the coating which were not especially detrimental because of the nature of the protection afforded by the electropositive zinc coating.

Although I have thus shown and described my invention in considerable detail, I do not wish to be limited strictly to the exact and specific details shown and described, but I may also use such substitutions, modifications, or equivalents thereof as are embraced within the scope of the invention or as are pointed out in the appended claims.

Having thus described my invention, what I claim as new and useful and desire to protect by Letters Patent is:

.1. An apparatus for producing uniform ductile coatings on rods and the like coated with molten metal, comprising a plurality of aligned air rings for smoothing the coating and making uniform the coating thickness, and means for rapidly advancing and spinning the rod through the air rings.

2. An apparatus for producing uniform ductile coatings on rods and the like coated with molten metal, comprising a plurality of aligned air rings for uniformly removing excess metal and rendering the remainder smooth and even, and conveying mechanism adapted to spin the rod in the course of travel in a line substantially coinciding with the center of the air rings.

3. An apparatus forproducing uniform ductile coatings on rods and the like coated with molten I metal, comprising a plurality of driven rolls havand advanced by the rolla having their axes skewed in relation to the .direction of travel of the coated rod, means for rotating said rolls means for supplying a heated fluid under pressure, and means fordirecting said fluid under pressure against and around the peing their axes inclined to the line of travel of the idle roller to accommodate different sizes 'ofriphery of the coated rod.

5.- An apparatus for producing uniform ductile coatings on rods and the like coated with molten metal, comprising a plurality of hollow rings perforated and adapted for directing Jets of fluid with substantial uniformity about the circum; i'erence of the rod,-and'spinning and conveying means comprising a series of skewed driven rolls one or more of which are magnetized.

6. An apparatus for producing uniform coatings on threaded rods .and the like coated with molten metal,'comprising a pair of spaced air.

' J 8. An apparatus 7. An apparatus for producing uniform coatings on hot-metal coated sucker rods or the like,-

comprising a pair of skewed magnetic rolls for advancing-and spinning the coated sucker rods, a pair of adjacent air rings for smoothing and evening the coating on the sucker rods, an idle roller for. directing the sucker' rods through the air rings, and means for manually adjusting the sucker rods. l

for producing uniform ductile coatings on rod-like metal articles comprising a pair of aligned air rings, and a pair of skewed drivenmagnetic rolls situated therebetween.

9. An apparatus for producing uniform ductile coatings on rod-like metal articles comprising a pair of aligned hollow rings adapted for .the pasrings suitably perforated for delivering a stream of air onto the coated surface atan angle of approximately 45 to the plane of said surface to wipe excess coating metal therefrom-a pair of skewed driven rolls therebtween each having a magnetizable periphery, coil windings in alignment with said rolls, a magnetic circuit energized by said coil windings and including said rolls, and guide means for insuring the proper contact and direction of the coated rod as it is rotated sage therethrough oi the coated article, each of said rings having a circular series of openings directed toward the article, meansfor supplying a heated fluid air to the pair of hollow rings, and

a pair of driven magnetic rolls situated between the aligned hollow rings in skewed relation thereto for simultaneously rotating and conveying the rod-like article through the rings,

10. An apparatus for producing uniform ductil coatings On'hOt-dip galvanized sucker rods comprising a pair of aligned air rings, a pair of motor'driven magnetized rolls skewed with respect to the common center line of the air rings and placed between said, air rings for spinning the rods while advancing said rods therethrough, andan idle guide roll placed between and above the magnetized skew rolls to assist in aligning the rods passed through the apparatus. I

ALLEN S. MOORE.

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