US1618142A - Method of making hollow bars - Google Patents

Description

Feb. 15 1927.

T. B. WHEELWRIIGHT METHOD OF MAKING HOLLOW BARS Filed May 12, 1926 gum #14304;

Patented Feb. 15, 1921. a

rnoms s. wnnnnwnrenr, or nocxnnan srnmes, v'meirmnssreuonro on) men & STEEL wonxs, or RICHMOND, vmemm. A oonroaa'rron or noimuon 1,618,142 UNITED STATES; PATENT n METHOD OF M AKIN G HOLLOW BARS.

Application filed May 12, 1926. Serial No. 108,303.

This invention relates to the manufacture of rolled or drawn hollow articles; and is especiall applicable for making stay-bolt iron, alt oug it may be applied to many other pur oses.

Hereto ore long hollow bars have been made by takinga solid billet .and drilling it from end to end, and then rolling down to size. Stay-bolt iron has usually. been;

rolled; then cut to length; and then drilled.

This is a costly operation because of the loss of metal, and the labor incident to the drilling. There has, also been difiiculty in' producing a itslength. I

My invention consists essentially in the economical production of hollow bars by building up a hollow fagot by arranging rods or bars around a hollow metal core, heating the built-up fagot to a welding. and rolling temperature, rolling the heated fagot down to the required size and section, at the bar with a straight hole through same time. preserving the desired direction.

of the hole through the axis of the bar.

A fagot may be built up of plates, flat bars, and even of scrap; but the resulting bar would not be suitable for the manufac-' ture of sta bolts, in which great strength and reliab' it are essential. I have found that by buil ing upmy fagot of bars of.

small section, and themselves of good quality, and then by rolling down by steps to the required size, I obtain a finished bar of unusual strength and soundness. I r

I-u'se my roceSs particularly for the production of iiollow staybolt iron, from end to end of which runs a tell-tale hole; but I do not limit my process tothe production of hollow iron bars, for by the same process I can produce hollow bars of ther weldable materials such as lowc'arbon steel.

In describing my process I use, for theenveloping cure them sake of brevity. and simplicity.- terms appli- Re ferring totheaccompanymg drawings which form a part of this specification; Figure 1 shows in' endelevation'a method of building upa fagot. v Figures 2, 3, and 4 show other methods of building up the fagot.

f Figure 5 shows a fagot in side elevation.- Figure 6 shows a'detail of the rolls. 3 Fi re 7- shows in detail the manner in whic the bore of the finished bar is cleaned.

"t e first and n qa -ry g o t my p' entian I P 4? a fagot by assembling iron bars or rodsaround a.hollow central core, as shown 1n Figures 1, 2, and 3. In Figure 1 the fagot H is formed by setting up a wrought iron p pe A; and concentrically with this pipe I set up another second and smaller wrought iron pipe B -of the same length. Thespace be tween these pipes I then pack with iron bars or rods 0, with the axes of the bars lying approximately parallel to the axes of the two pipes. The sizes of the two pipes will depend very much upon the length of stay-bolt.

iron which it is desired to roll; but for usual lengths the size of the outer pipe A may be from 4-lllChGS to.6 inches, andthe size of the smallerpipe may be fr'onf 1. inch to 1% inches. The length of the two pifies ispreffrably 30 inches; though it may ,ess

Another way of making this fagot is e more 01* shown in Figure 2. Itis not always desir- 'able to use a piece ofcommercial wrought packed into the space between the semi-circular plates D and hollow iron core B.

-E. The wrought iron rods or. bars are theng In Figure 3 I show another method of I forming the fagot. In this case I set u in a form flat bars F of suitable width to 'orminsection an octagon or a hexagon, or other polygonal figure, of the desired size. the hollowwrought ter; then I ack the space between it and the surrounding plates with, the wrought iron "rods or bars G; and then I wrap the plates aroundwith wire to se-- moved from the form.

The fa'got may be built-up 1n other ways;

for instance, by suitably arranging therods -orbars around the hollow metal core, and

.then wrapping the bundle tightly with wire,

inafter; andI then thrust the fagot into a ,heati furnace, and raise, to a welding and rollmg' temperature. I then remove I.set iron core B n the .cen-

in vlace. before the whole is reasinFi re4., The fa got built up I fill the core w th refractory material, as explained herethe fagot, and send it immediately throng:

su c eding p c i th It has been found that if a hollow billet 01 fagot is rolled through succeeding circular passes, it will turn and twist, so much so that the hole through the center of the bar will become very much distorted, and may even atplaces become closed. I have found that "I can prevent the turning of the bar, as it is reduced by the rolls, by using rolls having passes octagonal or hexagonal in shape,

in other words polygonal, rather than one sided, such as the circular pass. In the drawings I have shown rolls having octagonal passes II. It should be noted that in feeding the bar J into a pass I do not turn the bar so that its anglesv come in contact with the flats of the pass; but I feed it in with its flats in approximately the same planes as the flats of the pass. Bythis manher of feeding, the bar is less liable to distortion; and it is more readily reduced to iron.

-During the process of heating and rolling, the center hollow core, and the rods, and the outer envelope become welded together; and there is produced a long bar of accurate size, perforated from end to end with a small hole. In the case of bar rolled for stay-bolts this hole is usually to of an inch in diameter.

In order to prevent the collapse of the inher metal core during the heating or rolling, I pack the said core with a refractory material, G, preferably without any binding" material, except that with some refractories I may use a small quantity at each end to hold the refractory material in place during gthe heating and the first part of the rolli gfer the fagot. 1 My usual practice is to plug the ends of the metal core after filling itwith the refractor materials. For the f-refractory materiaL may use any sub: stance which will not fuse at a rolling temperature for example, silica sand, soap.-

stone, graphite, carborundum sand, zircon sand, electrically sinteredalumina, or magne'sla, or any other granular or powdered refractory material the fusing point of which is higher than the temperature of the metal when heated for rollin The removal of 'the refractory material from the finished bar-has heretofore been a difficult operation, and a costly one. I have found a simple and inexpensive method of removing therfractory core. I" mount the bar in a lathe or other machine b which it may be revolved on its a xis'gaand metal tube, approximately aslong as the bar, and of a size small enough to enter the core-hole'easily, to a source of supply of compressed air. I start the bar '(see M in Figure 7) revolving more or less rapidly,.

and I then introduce the free end of the metal tube, N, into the end of the core-hole; and turn on the compressed air. Theobject of rotating the bar is to produce a relative rotary motion between the core and the jet of compressed air. ,The jet of air then acts upon the core in somewhat the same way as.

connect a suitable rests. The pressure of air I prefer to use is approximately '100 lbs. per square inch; though other pressures may be used. This pressure is elfectivefor the removal of the core; and it is also a pressure commonly available in industrial plants. As the hollow tube is-inserted into the end .of the corehole the refractory is loosened by the rapidly flowing air, but not necessarily by contact with the end of the tube; and the loosened refractory is expelled rapidly from the core backward around the tube. By this method I am able to remove the core cleanly and rapidly, and at a very small cost.

I claim:

1. The method of making hollow metal bars, which comprises bundling weldable metal around a hollow core also of weldable metal to form a fagot; packing the hollow core withrefractory material; heating the fagot to a welding and rolling temperature rolling the fagot through a seriesof polygo- ;nal passes to the desired dimensions; and removing the refractory core by advancing compressed air into the hollow bar through a tube at the same time changing the relative positions of the bar and tube ,abouttheir axes.

2." The method of making hollow metal bars, which comprises bundling weldable rolling the fagot to th e desired dimensionsy and removing the refractory core by advancing compressed air into the hollow bar through a tube at the sametime changing the relative positions of the bar and tube about the r axes, I

.rods' around a hollow core also of weldable 3. The method of making hollow metal metal to form a fagot; packing the hollow core with granulated refractory material; heating the fagot to a welding temperature; rolling the fagot to the desired dimensions; and removing the refractory core by advancing compressed air into the hollow bar through a tube, at the same time revolving the bar. i A

4. The method of making hollow metal bars; which comprises bundling weldable metal around a hollow core also of weldable metal to form a fagot; packing the hollow core with refractory material having a fusing point higher than the welding temperature of the core; heating the fagot to a weld ing and rolling temperature; rolling the fagot through a series. of polygonal passes to the desired dimensions; and removing the refractory core by advancing compressed air into the hollow bar through a tube at the same time changing the relative positions of the bar and tube about their axes.

5. The method ofmaking hollow metal bars, which comprises bundling weldable metal around a hollow core also of weldable metal to form a fagot; packing the hollow core with refractory material having a fusing point higher than the welding temperature of the core; heating the fagot to awelding and --rolling temperature; rolling the fagot through a series of polygonal passes to the desired dimensions; and removing the refractory core by advancing compressed air into the hollow bar through a tube, at

the same time revolving the bar.

' 6. The method of making hollow metal bars, which comprises bundling weldable metal around a hollow corealso of weldable metal to form a fagot; packing the hollow core with refractorymaterial having a fusing point higher than the welding temperature of the core; heating the fagot to a welding and rolling temperature; rolling the tag 0t through a series of polygonal passes to prevent distortion and through a circular pass to the final desired dimensions; and removing the refractory core.

7. The method of making hollow metal bars, which comprises bundling weldable metal around a hollow core also of weldable metal to form a fagot; packing the hollow core with refractory material havinga fusing point higher than the welding temperature of the core; heating the fagot to a weld ing and rolling temperature; rolling the fagot through a series of polygonal passes to prevent distortion and'through a pass boundj In testimony whereof I ed by one line to the final desired dimensions; and removing the refractory core.

8. The method of making hollow metal bars, which comprises bundling weldable metal around a hollow core also of weldable metal to form a fagot; packing the hollow core with refractory material having a fusing point higher than the welding temperature of the core; heating the fagot to a welding and rolling temperature; rolling the fag- 0t through a series of polygonal passes to prevent distortion, the sides of the bar being presented parallel to the sides of the passes; and removing the refractory core by advancing compressed air into the hollow bar through a tube, at the same time revolving the bar. v

9. The method of making hollow metal bars, which comprises bundling weldable metal around ahollow core also of weldable metal to form a fagot; packing the hollow core with refractory material having a fusing point higher than the welding temperature of the core; heating the fagot to a welding and rolling temperature; rolling. the fagot to the desired dimensions; and removing the refractory core by advancing compressed air into the hollow bar through a tube at the same time changing the relative positions of the bar and tube about their axis.

10. The method of making hollow metal bars, which comprises bundling weldable meta] around a hollow core also of weldable metal to form a fagot; packing the hollow core with refractory material having a fusing point higher than the welding temperw ture of the core heating the fagot to a welding and rolling temperature; rolling the fagot to the desired dimensions; and removing the refractory core by advancing compressed air into the hollow bar through a tube, at the same time revolving the bar.

- .11. The method of making hollow metal bars, which comprises bundling weldable rods around a hollow corealso of weldable metal to form a fagot; packing the hollow core with refractory material having a fusing point higher than the welding temperature of the core; heating the fagot to a welding and rolling temperature; rolling the fagot through a series of polygonal passes and a circular pass to the desired dimensions; and removing the refractory core by advancing compressed air into the hollow bar through a tube,

fixed my signature.

THOMAS s. VVI-IEELWRIGHT.

have hereunto af-

Images