US 1539833 A
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Description (OCR text may contain errors)
June 2, l925 l 1,539,833
F. A. FAHRENWALD CONVEYER ROLL FOR FURNACE USE Filed June 26, 1924 l l l Aorzzeys Patented June 2, 192.5.
UNlTEDsTATEs PATENT lOFFICE.
CONVEYYER ROLL FOR FURNACE USE.
Application led .Tune 26,1924. Serial No. 722,545.
T aZZ whom t may concern.'
Be it known that I, FRANK A. FAHREN- WALD, a citizen ofV the United States of v America, and a resident of Cleveland l Heights, in the county /of Cuyahoga and State of Ohio, have invented certain new and usefulV Improvements in Conveyer Rolls for Furnace Use, of which the following is a full, clear, and exact description.
This invention relates to high temperature apparatus and has especial reference to a furnace of the continuous process type. In order to anneal steel and other metal sheets, cure glass, glaze pottery, and perform other technical operations at high temperature it is necessary to subject the same to a high temperature and theoretically the cheapest and most convenient course is to convey the articles continuously through a heatedv region. One of r.the most extreme cases occurs in the annealing of steel sheets in which the same are passed .in horizontal position through a'furnace heatedalmost to the melting temperature. It is necessary to support these sheets at very small intervals, and move them very rapidly lest they sag by their own weight and clog the furnacecompletely, but difficulty has been experienced in devising rolls vor other supports which shall withstand these high tem eratures without cracking, warping, or disiiitegrating, for which reason this type of furnace has no been practically available.
The objects of my invention are the provision of a wheel or roll which can be used under the conditions stated for an indefinite length of time without cracking, warping or disintegrating; the provision of a wheel or roll that will operate under tem eratures of 2000 F. or more; the provision of a wheel or roll which will withstand indefinitely the strain produced by a difference of temperature of 1000 Fahrenheit between the rim and hub; the provision of a new and improved type of wheel or roll for the purpose in view; while further objects and advantages of the invention will become apparent as the description proceeds.
In the drawing accompanying and forming a part of this application I have sho-wn one form of my invention wherein, Fig. 1 is a vertical sectional view and Fig. 2 a horizontal sectional view of an industrial furnace equipped with my invention, and corresponding respectively to lines 1 1 of Fig. 2 and 2-2 of Fig. 1; Fig. 3 is a face view of one ofthe wheels drawnto larger scale, the shaft being shown in cross section; Figs. 4 and 5 are respectively side elevation and cross section of the shaft` with the wheel removed; and Fig. 6 is a reduced sectional View of a modification.
Furnaces of the types shown inl Figs. 1 and 2 are oftentimes 40 to 50 feet long and 8 to 10 feet wide comprising side walls 1 1 and roof 2 of any suitable. refractory material. Projecting horizontally through apertures in the side walls are avery con.
siderable number of horizontal hollow shafts 3 3, suitably synchronized by means of gearing such as sprocket wheels and chains 4 4 outside of the furnace and having their ends connected by suitable swivel joints 5 5 to conduits (not shown) whereby water, air, or other cooling fluid is circulated therethrough. Inside the furnace each shaft is provided with a number of wheels or rolls of a diameter varying from say 10 inches to 20 inches or more. The shafts are so close together that the rolls overlap, and the rolls are so spaced u onthe shafts as to support a sheet or Iate with substantial uniformity. A sing e furnace oftentimes contains as many as 300of these rolls. The speed varies with the work being very fast with most metal sheets and slow with clay and ceramic workA or some types of heat treatment.
According to my invention each of these wheels conslst of a continuous circular rim 10 having integral spokes 11, the inner ends of the spokes being integral with segmental portions 12-12 spaced apart from each other to define slots 13-13 and the segmental portions together defining hubs. The interiors of these hubs are reamed to iit the shafts 3 3 (since heating expands the hubs faster than the shafts) and driving is preferably `effected b means of collars 15 keyed to the shaft an formed at one side with rectangular teeth 16, which fit looselyl in the slots 13 13. The shafts 3 3 can be made of common steel tubing of the same kind that is used in making steam boilers since the conditionsto which they are subjected are no more severe than are encountered in boiler practice. Preferabl I make the wheels of my alloy known as ahrite consisting essentially of 1/2 iron, rl; nickel,
1A; chromiumV and from th% to 2% of silicon since this alloy will withstand continuously a temperature upwards of 2000- often differing from the rim by as much asl 1000o yet without producing such internal strains as to cause breakage.
I do not limit myself to the use of my improved wheels in this one way since it will be understood that many ,changes in this and other details canv be made within the scope of my invention. I do not limit myself as regards the width of the face of the wheel or roll since the same maybe made of any width compared to the diameter and added rows of spokes employed; in such case I do not restrict myself to having the hub severed into longitudinal segments aswell as angular segments although I lprefer to do so. Also I do not limit myself to the use herein illustrated nor in any other manner except as recited in my several Yclaims which I desire may be construed,`
each independentlyv of limitations inother claims. t
I-Iaving thus described my invention what I claim is: Y Y A l. A roll for the purpose described comprising a continuous circular rim, spokes integral therewith, and segmental blocks integral with the respective spokes and collectively. definingl a hub,said blocks being separate from each other. j v g 22A roll for furnace use `comprising spokes, a rim, and a hub constituting a unitary article, the hub consisting of independent segments, one for each spoke.
3. A'- device of, he character described made of heat resisting alloy and comprising a rim, radialspokes, and independent blocks carried by the inner ends of said' spokes, said blocks being spaced from each other and projecting laterally beyond the rim.
4. The' combination 'with' a hollonT shaft and means 'for 4delivering a cooling fluidthereto, of a roll carried thereby havingfa' continuous rim, spaced spokes integral. therewith, and a hub integral with saidl spokes, said hub being slotted between adj acent spokes to form independent segments.
5. In a furnace, the combination with a shaft, of a collar thereon having laterally projecting teeth and a roll having a continuous rnn, spokes integral therewith and` a hub integral therewith, said hub having slots between adjacent spokes which extend from end to end thereof and separate the same into independent segments, said teeth fitting into `said slots in driving relation. v
6. A furnace rollmade of a single integral casting of high temperature alloy having a c lindrical rim portion, and spokes, and 'a ub, said hub Vhaving longitudinal slots extending from end to end between -each pair of angularly related spokes.
In testimony whereof, I hereunto alii'xv my signature. A
l FRANK A'. FAHRENWALD.