US2174880A - Method of cleaning elongated metal shapes - Google Patents

Description

Oct. 3, 1939. J. M. HILBISH ET AL METHOD OF CLEANING ELONGATED METAL SHAPES 2 Sheets-Sheet l Filed Oct. 5, 1938 ATTORNEY.

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IIIII Oct. 3, 1939. J. M. HILBISH ET AL 2,174,330

METHOD OF CLEANING ELONGATED METAL SHAPES Filed Oct. 5, 1938 2 Sheets-Sheet 2 INVE NTORS Z ATTORNEY.

Patented Oct. 3, 1939 UNITED STATES PATENT OFFICE HAPES Joseph M. Hilbish and John K. McCahan, Pittsburgh, Pa.

Application October 5,

1 Claim.

This patent application is in part a division of our joint patent application Serial Number 133,991, filed in the United States Patent Office on March 31, 1937 which matured into Patent No.

62,134,557, October 25, 1938 and also in part a division of our joint patent application Serial Number 205,936, filed in the United States Patent Office on May 4, 1938.

Our present invention relates to improved methods for cleaning scale, rust, pitting and the like from the surfaces of elongated metal objects such as steel billets, slabs, bars, rods and other shapes, and also for coating the clean shapes with substances to prevent further corrosion.

Billets, slabs and other shapes of unfinished steel are characterized by rolled-in scale, rust and other surface impurities and defects which must be removed before the shapes are further fabricated or brought into finished form.

The method usually employed for this purpose is the pickling of the shapes in an acid bath.

This method is time-consuming and expensive,

and the length of the shapes which may be pickled is of course limited by the capacity of the pickling vat. Moreover, the acid of the bath is likely to pit the metal and especially in the case of special steels the consequent loss is substantial.

The average cost of the pickling treatment is from one to fifteen dollars per ton of steel, while the commercial use of our invention has reduced this cost to as low as from twenty-five cents to fifty cents per ton.

Another method in frequent use for cleaning rusted and pitted steel bars, rods, tubes and other elongated shapes is to use hand or machine brushing, one article at a time being treated.

The records of one of the large steel mills disclose that it takes at an average approximately forty minutes to clean by brushing a sixteen foot length of No. 12 gauge band steel of 2% inches in width, while with the use of our invention three tons of like material are effectively cleaned in twenty minutes.

Sand blasting is another method of cleaning in use, but with this method elongated shapes must be separately treated and, owing to the time and labor consumed, the expense is very much greater than in the use of our method.

In our method we load a quantity of the elongated shapes into a cylindrical container of greater interior length than the lengths of the shapes and of greater cross-sectional capacity than the combined cross-sectional area of the shapes. We then rotate the container on its lon- 55 gitudinal axis and simultaneously tilt the con- 1938, Serial No. 233,404 (01. 51-278) tainer on its longitudinal axis alternately in opposite directions. 3

The rotation of the cylindrical container causes the individual shapes to climb or be drawn upwardly along the interior wall of the container in the direction of rotation, which action is increased by providing the container with a polygonal side wall instead of one of truly annular form. As the shapes are raised they fall back on the remainder of the shapes, resulting in a continuous series-of hard impacts which loosen the scale, rust and other substances, and the tilting of the container alternately in opposite directions causes an attrition between the lateral surfaces of the shapes temporarily in motion and those temporarily at rest or moving at a different speed. This results in attrition which further loosens the scale and rust and dislodges the same so that it accumulates in the lower portion of the container. The combined use of impact and attrition in our method also effects the successful removal of pitting.

The cleaning operation may be expedited by placing in the container a quantity of sand, coke dust, hard metal scale or other suitable abrasive material.

Again, after metal shapes have been cleaned of rust, scale and other surface defects, the cleaned surfaces are more susceptible to rusting than they were before cleansing.

In the practice now in general use, the cleaned shapes are coated; either by brushing or dipping, with some corrosion-preventing substance, usually a compound containing tallow or graphite or both. This operation, accomplished either by brushing or dipping, is time consuming and expensive, especially in the case of elongated shapes.

In our method we place the cleaned elongated shapes in the container together with a sufficient quantity of the corrosion-preventingcompound and then rotate and tilt the container, inthe manner above described, and in a very short time, a fraction of the time required when the methods of coating above referred to are employed, an evenly distributed and adequate coating of the substance is applied'to the surfaces of the shapes.

The rotation and tilting of the container during the cleaning operation may be such as to impart an orbital movement to the opposite ends of the container, but where the shapes to be cleaned are of relatively small cross-section, such for instance as relatively slender bars, rods and thin strips, such an orbital movement tends to twist and bend the shapes longitudinally and sometimes even entangling them with each other, so that the same require subsequent straightening.

Therefore as a further improvement in our invention we rotate the cylinder on its longitudinal axis and simultaneously tilt it longitudinally alternately in opposite directions but confine such tilting to substantially the same vertical plane. By this means any tendency of the shapes tobecome bent or twisted is avoided and the cleaned shapes do not require subsequent straightening or other correction.

In the accompanying drawings, wherein we have illustrated apparatus suitable for working our invention,

Fig. 1 is a side elevation of one form of suitable apparatus.

Fig. 2 is a cross-sectional view taken along the line II-II in Fig. 1.

Fig. 3 is a like view taken along the line III-III in Fig. 1.

Fig. 4 is a like View taken along the line IV-IV in Fig. 1.

Fig. 5 is a broken elevation of one of the removable end closures.

Fig. 6 is a side elevation of another form. of suitable apparatus.

Fig. 7 is a cross-sectional View taken along the line V'.[IVII in Fig. 6.

Fig. 8 is a cross-sectional view taken along the line VIIIVIII in Fig. 6 showing the hoisting mechanism.

Referring first to Figs. 1 to 6 inclusive, of the drawings, l represents a longitudinally extended cylindraceous container of sufiicient length toreceive metal shapes of the proper lengths. In practice we find that in many instances the container should be long enough to receive bars, rods and other shapes of at least seventy-five feet in length. As will later appear, the interior length of the container should be greater than that of the material which is to be cleaned or coated.

The cross-sectional shape of the container l is preferably polygonal, such as octagonal, instead of annular, since where the container is a true cylinder, the bars, rods or other shapes when the container is rotated, tend to slide down and remain more or less quiescent in the bottom of the container. while where the container is of polygonal cross section the rotation of the container tends to carry the articles up along the side of the container whence they fall down and thus the articles are continuously impacting against each other.

Thus any portion of the bar or other shape moves in an orbital path transverse to the axis of the container.

Adjacent either end of the container the latter is supported in a suitable manner.

Thus we provide a pair of stands 2 mounted on either end of a base 3.

The stands each may be formed of a pair of parallel plates 4 which are in spaced relation to each other and preferably have arcuate upper perimetral edges as shown in Figs. 2 and 3.

The plates 4 are provided with registering.

circular openings 5.

Between the plates 4 of each stand 2 is moun ed a circular head6, concentric with the opening, which is rotatably supported in place by a plurality of grooved rollers 1 mounted between the plates 4 as on axles supported at their ends by said plates.

Each of the heads 6 is provided with an opening 8 of the proper size and contour to snugly receive the container l and the heads are fixed to the container in any suitable manner, as by welding.

The openings 8 are not concentric with the heads 6 but eccentric thereto, as illustrated in the drawings, the head adjacent one end of the therefore their surfaces rub against each other,

resulting in attrition.

Intermediate of the ends of the container the perimetral surface of the same is provided with one or more radially extending annular flanges 9 to the side surface of which is bolted or otherwise secured a ring sprocket it connected by a drive chain It with a power-driven sprocket l2.

The ends of the container are provided with removable closures to permit the loading and unloading of the container.

Thus we show the extremities of the container provided with outwardly extending annular flanges l 3 provided with bolt holes. M represents the circular end closures or lids of like diameter as the flanges l3 and provided with key-hole bolt openings Hi, the diameter of the openings being large enough to give clearance to the heads of the bolts I505 and the smaller slotted portions of the openings being of the width to give clearance to the shank of the bolts. The openings [5 are so disposed that the head it may be turned into position with the larger portions of the openings i5 registering with the heads of the bolts when the lid may be placed in position with bolts protruding through the openings. The lid is then rotated sufiiciently to move the bolts into the slotted portions of the openings and the nuts are then tightened on the bolts and the lids clamped in place. To remove a lid the nuts are loosened and the lid rotated to bring the bolts into registration with the larger portions of the openings.

To assist and expedite the cleaning action we may and usually do place some suitable cleaning material in the container, such as sand, coke dust corrosion resisting properties, such material is k placed with the metal objects in the container, the end-closures are put in place, and the container is rotated. As the result of the rotary and tilting movements of the container a uniformly distributed coating of even thickness is quickly applied to the objects.

We have found that a suitable compound for this purpose may be produced by mixing tallow, kerosene, graphite and sawdust or some other suitable carrier. Thus we have successfully employed the proportions of ten pounds of tallow, one gallon of kerosene and two and one-half pounds of graphite.

Where the shapes are slender or of relative small cross-sectional area, we find that where the container is given what may be termed an orbital movement as above described in connection with Figs. 1 to 5, inclusive, there is a tendency for the shapes to become bent, twisted and in some cases intertwined with each other, thus requiring straightening or other reworking before use or additional fabrication.

In Figs. 6 to 8, inclusive, of the drawings, we illustrate a form of apparatus wherein such shapes may be cleaned and also coated without danger of such distortion or intertwining and wherein the alternate tilting of the container in opposite directions is confined to substantially one vertical plane, thus obviating orbital movement of the container.

This apparatus is as follows, reference being had to Figs. 6 to 8 inclusive of the drawings.

I6 represents a cradle comprising two sets of transversely disposed square plates I! held in spaced relation by the diagonal load members I3, and mounted on the base platform I9. 20 represents a top platform supported by the plates I1.

Each set of plates I1 is held in spaced relation to receive between the same the grooved idle rollers 2I which rotate on axle pins 22 held in said plates. The axes of the pins 22 are positioned to intersect diagonal lines drawn from the corners of the plates I! and are oppositely disposed to one another in quadrangular relation so as to intersect the circumference of an imaginary circle drawn from the intersection of said diagonal lines as a center.

A circular opening 23 having the same center is cut in each plate, thereby exposing a portion of the perimetral surface of the rollers 2! as shown in Fig. '7.

24 represents a pair of circular disks interposed between sets of plates I1 and the perimetral edge of which engages the grooves of the rollers 2I. Thus a disk 24 is rotatably mounted upon the rollers 2! of each set of plates Il.

These disks 24 are each provided with a concentric opening 25 to receive the container I which is fixed to the disks as by welding. The ends of said container is provided with removable end closures as described in connection with the previous figures of the drawings.

26 represents a motor mounted on the platform 20 and coupled to the speed reducer 21 to drive the shaft 28. 29 represents a sprocket pinion fixed on the shaft 28 and connected by the chain 30 with a ring sprocket 3| surrounding and fixed to the container I. Thus the container I is rotated by the motor 25.

The base I9 of the cage I6 is pivotally supported intermediate of its ends on the aligned horizontal bearings 32 mounted on suitable foundations 33. Thus the container may be tilted in a vertical plane on its longitudinal axis. The axis of tilting is adjacent one end of the container.

The other end of the drum I is supported by a hanger 34 comprising a yoke 35 which is provided with an eye 35 at its upper end to receive the hook 31 of a hoist or lift 38. The lower or bifurcated ends of the yoke 35 are provided with aligned bearings 39 arranged to receive the gudgeon ends of the shaft 49. The intermediate portion of this shaft is preferably square to permit the assembly of the parallel plates 4| on opposite sides thereof. These plates are similar to the plates I! in that they are constructed to support the triangularly disposed pins 22 which rotatably carry the three idler rollers 2!. The plates are provided with aligned openings arranged to receive the container I and support the same by means of the circular disk track 24 riding on the idler rollers 2i. This structure permits the lift or hoist 34 to tilt the container I about the axis of the bearings 32 while the container is being rotated.

Swiveled rollers 42 are provided on the ends of the the shaft 4!! and on the upper end of the yoke 35. These rollers are arranged to ride on the wide vertically disposed tracks 43 and prevent the container from being moved laterally as the load is rolled and shifted therein. The hoist or lift 38 may be hydraulic, pneumatic or an ordinary electrically driven hoist. In either case the valves 64 of the hydraulic or pneumatic hoists must be capable of being cracked so as to enable the operator to change the speed of tilting the drum during the proper periods of its operating cycle. The same character of control is required of the electrical hoist. The operator is thus enabled to control the rolling and shifting of the load as the objects are being cleaned and coated. Thus a lift having a very quick or fast speed and a slow speed with a series of intermediate steps therebetween is advantageous for use with this apparatus. A short or quick lift or drop adjacent the upper or lower tilting positions of the container I creates a shock on the load therein causing it to shift to the lower end thereof.

The method involved by the use of the structure illustrated in Figs. 6 to 8, inclusive, has marked advantages compared to the structure illustrated by Figs. 1 to 5, inclusive, wherein the axis, upon which the container is rotated, itself travels in an orbital path.

Where the container rotates on an axis which travels in an orbital path, rods and other shapes of considerable length and of relatively small diameter are likely to become bent, distorted and twisted about each other, thus frequently ruining the material or necessitating a straightening operation. It has been found in the commercial use of this modification that such deleterious results do not occur due to the fact that the axis of the container does not travel in an orbital path but in a vertical plane. This is a very important improvement of this invention and efiects a very material saving both in labor and material.

We claim:

The method of conditioning the surfaces of elongated metal objects which comprises, placing a quantity of these objects in an enclosure, tilting the objects in a vertical plane to cause them to shift longitudinally back and forth with their opposite ends alternately elevated above the horizontal to produce attrition between the objects and the enclosure and between the objects themselves, and simultaneously rolling the objects to promote their sliding action, thereby reducing the necessary angle of tilting.

JOSEPH M. HILBISH. JOHN K. MCCAHAN.

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