US1908242A - Container for treating metal articles by heat - Google Patents

Description

May 9, 1933. J. c. HENDERSON CONTAINER FOR TREATING METAL ARTICLES BY HEAT Filed Sept. 23, 1930 2 Sheets-Sheet l ATTORNEYS May 9, 1933. J. c. HENDERSON CONTAINER FOR TREATING METAL ARTICLES BY HEAT Filed Sept. 25, 1930 2 Sheets-Sheet 2 lNV ENTOR Jblm iflmo'arz,

BY J 6; WM

ATTORNEYS Patented May 9, 1933 "JOHN C HENDERSON, OF- ELIZABETH; NEW JERSEY, ASSIGZN0ITO"DBIV1E$HABMS COMPANY,- OF HARRISON, NEW- JERsEY, ,A .coRroRAmtoN'oR JERsEm CONTAINER"FOR TREATING METAIJ ARTICLESBY HEAT Application filed September 23, 1930. Seri'aIWo; 488,915.

My" invention relates to containers for treating metal: articles by heat, "and: has:

special reference to carburizing: containers.

@arburizin'gr containers or boxes are com fi monly'madeof heat-resistlng alloys, such as:

tomwalls ieither icastiin I a single piece or else These carbur zmg' I made of rolled sheets.

boxes are sometimes as much as-fortyinches in'l'ength' by. eighteen inches in width, and consequently in case ofsingle plece cast boxes-a largemold must be made which re quires large: molding: and flask' equipment; Moreover, with-such cast boxes in order for the metals to-fiow into themolds properly and-to-insure adequate strength, it is necessary to make I the walls of substantiali thickness-,- the required thickness 1 varying with the cubical content of the *box:- The heat resisting" alloy is: expensive and; therefore,

any increase -in thickness adds to the expense of'ma'rmfacturathe boxes-are heavy and 255 bulliy to handle;- and the thick: walls ab: sorh" more'= heat than necessary when: the boxes are-in use Still-another disadvantage ofsuch cast boxes is that it: is difiicult to cast-the walls =of uniform thickness-through outyandanythin place in the walls would be likely" tocause objectionable expansion andicontrantion strains to be set up in the boxes.- Moreover blow-holesare likely: to

occur in the-casting which are notvisible While carburizi-ng boxes made of cold rolled" sheet metalrequirea less amount of material and are appreciably less expens ve thanxa-boxnnade -of' a sin le casting, they 40 also have numerous disa "antages- Gold rolled sheet metal is shapedandrolled froin ingots and, therefore, the metal must be'of' low fcarbon content inorder that it may be sufficiently malleable to roll easily. Owing- 'to such low carbon content, however, suchsheet metal hoxesha've aten'dencyto creep and grow whenmade ofheat-resistingialloy; which causes Warping and distortion' ofithe' WallsOf the hex, .and1.frequent1y= breaking of the welds: I The inetal'sheetsarehable i be: scaly; split or'otherwise defectiveal thoughthe defectsiinay notibe visible: when the' bo'xi is' fabricated hut materially affect the hate-011 the box The several: sidew'a'lls of the box are usually for-medxofm single piece of sheet metal, and the bending-.1 operation IQqIIlIEECl lS expensive;

The principal object of thepres'ent in vention is to overcome the disadvantages above described of th'e' carburi'zi'ngihoxes as heretofore constructed," while retaining all'='- of: their advantages:

In-thedrawings:-

Figure 1 is a View in perspeot'ivaof a can c buriZing'bo-x embodying the 'featu-res of my' invention in-their: preferred form; 1 I

Fig. 4; 5 and (i al c views in erspective* of the- 'bottomi-wall and two of the si'd wal-ls of-the-box;

Fig. is a view' inperspective of? a side-- wall 01E the box made-up of z a pl'Iurality of cast pieces secured'togetl'i'er";

Fig. 8 is a sectional vi'ewtaken; were line 8"8 'ofFig; 7 l a Fig. 91s a View inpersp ectivegof atcomponent part of the side wall? shown in'F'igh 7-;

i Fig, 10 is aVieW-i'nperspective of'fa'cylins drical-box; and p i it Fig-.i 11 is-a; sectional view takenon the-:- line 111-1 0f- Eig.10. a

The carburizing; boxillustrated in? Figsii 9m:

1 to; 6 of" the drawings 'isr pnovi dejd xwitha' bottom wall 2, opposed side wallsi i -andi opsposed sidewalls The several walls afre each made otsa single "sheetica'st of the alloy referred: to in i m'y said 1 patent? Asi the bottomwall is provided with: an up standing marginal rih"8; The vertical edges of the side walls-4 are=- provided with in wardly prejecting ribs 1O; and th eso-side walls and the side wallet" are: rovidedw mo side walls 6 abut against the inner sides of the side walls 4: and are positioned against the inner sides of the vertical ribs 10.

When the parts are thus assembled, weld; ing material-indicated at 12 is appliedto the corner formed by the marginal rib 8 of the bottom wall and the adjacent portion of the side walls, and to the corners formed by the vertical ribs 10 and adjacent portions of the side walls 6. The upper corners of the box formed by the abutting ribs 10 are also securely Welded.

With this construction it will be apparent that anextremely strong and rigid box is provided. The ribs 8 and 10 not only reinforce the corners of the box but also provide shoulders for effectively receiving the welding material so that there is no danger of the welds being burned out and broken while the box is in use. The upper marginal rib or band 11 effectively reinforces said edge so as to prevent breaking down by heat., 1

In casting the walls, the patterns may consist merely of a piece of sheet metal having strips secured thereon to form the ribs on the side walls when cast. It has been found that with the heat-resisting alloy em- "ployed, the castings may be of a thickness of but three-sixteenths of an inch and that awall of one-eighth of an inch in thickness ives the'necessary strength in most cases.

y making the walls of the box of thin sheet castings there is not the danger of blowholes as in the case of a single piece cast box, for the reason that the chilled surfaces of these thin castings meet each other and there is no intermediate area in which 'defects may occur.

condition to the user, who may easily as-' semble the parts and Weld the seams, so that there is a substantial saving in transportation costs. Also, in case one wall of the box becomes burned out or otherwise injured, it may be easily replaced upon melting the welds.

- In case it is desired to manufacture a box of such length that the walls thereof cannot be easily cast in a single piece, the walls maybe made up of several pieces 14 (Figs. 7, 8 and 9) having their edges welded together. The welding seam is preferably formed by anoffset portion 16 on one edge of onefpiece'providing shoulders 17 and 18.

The shoulder 17 abuts against the edge of the adjacent piece, and the shoulder 18 forms a corner with the adjacent portion'of the adjacent piece for the reception of welding material.

In making a cylindrical box the bottom wall may consist of a circular cast sheet 18 having an upstanding longitudinal flange 20, and the side wall may consist of a plurality of pieces 22 having overlapping seams 24 which are welded, the Welding seams being preferably of the construction of the seams shown in Figs. 7, 8 and 9.

In some cases where it is desired to make the box other than with straight sides, in stead of casting the walls in curved form they may be bent, it being found that. the thin castings of the alloy are capable of bending to a certain extent. Also, if desired the walls may be cast with reinforcing corrugations. .Furthermore, the walls may be of varying thicknesses to secure reenforcement as desired, such as by greater thickness at the center, which of course is not possible with rolled sheets.

Carburizing boxes are usually used in inverted position, but in cases where they are used in upright position a flanged cover may be provided. It will be apparent that the flanged cover may be constructed in a manner similar to the body of the box.

As will be evident to those skilled in the of the other sheet, and welding material applied to the corners formed by the upper edge of said rib on the bottom wall and adjacent portions of said side walls, and by the outer edges of the ribs on said side walls and the adjacent portions of the adjacent side walls so as to Weld the side walls together and to the bottom wall, each of the side walls having an outwardly projecting marginal rib at its upper edge so as to form a reinforcing band for the upper edge of the container.

2. A metallic receptacle for usein heat-- treating furnaces comprising spaced plates having flanges directed towards each other, plates having the ends thereof overlapping said flanges, and a flanged bottom member receiving the lower portions of said plates, said parts being joined together- 3. A metallic receptacle for use .in heat treating furnaces comprising side plates, channel end plates, and a cupped bottom of precast metal, and said parts being joined together by Welding.

4. A metallic receptacle for use in heat treating furnaces comprising side plates, channel ends and cupped bottom, all of precast metal and joined together by Welding, said cupped bottom forming a bumper and reinforcement.

In testimony whereof, I have signed my name to this specification.

JOHN C. HENDERSON.

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