US2026311A - Carburizing box - Google Patents

Description

Dec; 31, 1935. H. H. HARRIS CARBURIZING BOX Filed Aug. 9, 1934 2 Sheets-Sheet l INVENTOR HENRY H. HARRIS ATTORNEYS Dec. 31, 1 9,35- HIHARR|S I 2,026,311

. CARBURIZING BOX Filed Aug. 9, 1934 2 Sheets-Sheet 2 INVENTOR HENRY H. HARRIS #Mmq ' ATTORNEYS a, an advance over the art. Y

so constructed in I Patented Decmem s,

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l Application a,1as4 ,serie1m.s3s,13sf

This invention reietee to We and t is an improvementon the invention "ofnrv -Patent No. 1,882,580.

It is an object of my'inventiontdprovide a carburizing box :wmcn will standup. better and longerunderthe severe usage which such boxes receive. y his a further object'ofmylinventiontoprm;

1 vide a carburizing. box whichwill havea longer 1o servioelife in proportion to the :dimcultyand exf pense of making same. I; 1 Other objects will appear in, the course .ofthis about the edges of the center part B, with forks;

specification. so i H V i ,l when carburizingeboxes are tobe used in heat a v 15 treating furnaces, nietalgarticlespto bewcarburized are .plac'edin'F the boxes, together with a car I burizing agent ,such ,as, bone ;.du st.;;j#Irays are placedover theboxes, the boxes with their trays i are then usually inverted, andin this position,

so are subjected in a heattreatingfurnace to heat i usually supplied frombeneath. i e The boxes must stand up under rough han- H dling, extremely high temperatures, 7 sudden 1 changes in temperature, and "the pressure of a aa heavy load of contents I 1 s arping and buckling, prowhile softened by heat, all with attendantw du'cing cracks and ultimately breaking th'ebox down.

As a result, if the boxes were not madeso so to have great durability under such treatment they would have to be replaced constantly att g great expense, and it becomes'a problem of some.

nicety and importance todevise a box having the longest life in proportion to the cost of pro-f 8t du'cing same, in which my invention which is ilherewith represents lustrated in the drawings In said drawings, 1,- Fig. 1 is a pegspective view of one form of-box ccordancewith my invention; Fig. 2 is a longitudinalsectionalview thereof 2I'of Fig. 1; and N e Fig. 3 is a broken transverse sectionalfyiew onlinet-Iofligl, 45 gml 'lg. 4 is a plan view of a second form pf box f constructed in accordance with my inventions;

Fig. 5 is a side view thereof:

Fig. 6 is a longitudinal sectional view. thereof line He: Fig. 4;

Fig. 7 is'a transverse sectional'qview thereof on"? line 1-1 of Fig. 5; and

' 1 l 1, Fig. an a transverse sectional view mm: on

linel-l of m. 5;

I im the am formgshown in mg; 1-3, the box is' ,made up of three parts,- A.VB and 0. Theend parts-A and C providepartial'bottom andside walls and also end walls. The centeri part is U- shaped and open-ended, providing partial bottom andsidewallsx t -'I'he center part B isfonned. aiplurality of reverse curve corrugations extending .continuouslydownoneside, across the bottom and up i the other side, producing substantially aebellows which is free 't yield" principallydengthwise of the box. h 7 The-end parts Aand 0- preferably terminate in marginal portions facing each: other and cast ll and-l2 embeddingsame. it To securea locked joint, holes 13 are formed along; the edges of 15 B and ties I I; integral with the endparts are formed through these holes inthe casting :proe

securely lockingthe parts together.

1 Strips Ii are welded to the centerpart Belong 'its upper edge, forming a reinforcement. at. the

tent. They could, however, be'stamped of sheet metal, instead of cast, and the joints could be made in other way such as welding orriveting.

The center part B is preferably formed from a sheet of high grade ductileheat resistant alloy,

such as a high nickel chromium alloy that islow in iron content, and the strips ii are of the same material. i

In use the irregular expansion and contraction of the box has its greatest and most varied eflect longitudinally midway of the box. Such strains and variations are absorbed by the bellows part in this construction, same being relatively free, especially when made of sheet metal,

t expand, contract and twist in diflerent dlrec- 'tions moi'e freely than any previous construction. The longitudinally wavy corner bends of this construction peculiarly adapt it to expansion,

contraction and twisting. While a single corrugation formed in the center part has essentially 'a reinforcing effect, the reversecurves allow relatively free flexing to absorbs'trains which other-- wisewould jultimately break the box down. The

solid anchoring of the more iiexiblejcenter m -in the more rigid endparts insures that the strains willbe transmitted to the part which can harmlessly absorb them, instead of their breakingloosethejoints l In thesecond form, shown in Figs. 4-8, the box is made up of three parts E, F and G.

The end parts E and G provide partial bottom and side walls and also end walls. The center part F is U-shaped and open-ended, providing partial bottom and side walls. The two end parts are joined to the center part ,to. form a unitary box closed at-al1 sides but one.

The center part F is longitudinally corrugated all the way around, the corrugations running from joined edge to. ioined edge thereof, provid-; ing substantially'a bellows with freedom'to yield in most directions and principally across the bottom and up and down the sidewall portions, convex'corrugations 2|, 22 of larger radius being formed where the bottom wall bends up into the side walls. a

The end parts E and G have generally flat walls except part F. Near these edges the walls of the end parts start gradually to assume a corrugated form indicated by reference character 23, which at the edges matches the corrugated form of the center At the edges the end partsare formed with two 7 forks 24, 25, which lie on both sides of the-part F to secure the parts together. Positive locking between the parts is preferably secured by forming, holes 26 along the edges of the center part and casting the end parts directly about the cen-. ter part with the result that in the casting process ties 21 integral with theendparts are formed through the holes, securely locking the parts together.'

:The. center: part F is preferably formed from a sheet ofa high grade ductile'heat resistant alloy, such as a high nickel chromium alloy, with low iron content, while the end parts are preferably cast of a rugged relatively inexpensive metal or alloy, which may have a higher iron content.

In use the end portions provide the ruggedness to resist handling and rough usage; keep the expense down because made of cheaper material;

at the edges where they meet the center and are of a simple strong construction; but they cannot stand up so well under the strains of warping and buckling from temperature strains. The more ductile and flexible center part is provided to largely absorb these strains. The cor- 5 rugated form of the center part gives it more adaptability to bend and twist. As an example, if one end part should expand along its inner edge more than the other end part, this can all be taken up by a fan-like spreading of the cor- 10 rugated center part. The corrugating of the edges of the end parts makes a more pliable joint so'that both parts can accommodate themselves to each other. The solid anchoring of the more flexible part in the more rigid parts insures that 15 the strains will be taken up by those sections which can harmlessly absorb them, instead of their breaking loose the joints. While I have shown two specific forms to illustrate my invention, it will be apparent that vari- 20 ations thereof may be made within the spirit of the invention, and hence I wish to be limited only by thescope of the appended claims.

I claim: 1. A metallic receptacle for use in heat treating 5 furnaces comprising two end parts each being a single integral castmember of a relatively high iron content, alloy and each providing an end wall and a partial bottom wall and partial side walls, and a center part formed offlexible sheet metal 30 of a relatively low iron content alloy and providing a partial bottom wall and partial side walls and being formed throughout its area with a plurality of continuous reverse corrugations, the inner edges being cast aboutthe edges of the center .35 part and anchored thereinto.

2. Device of claim 1 in which the corrugations are longitudinal and the end parts, at their edges adjacent the center part, gradually change from flat surfaces to corrugated form corresponding 40 with the corrugations of the center part. I

HENRY H. HARRIS.

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