US2540052A

US2540052A - Porcelain enameled tank

Info

Publication number: US2540052A
Application number: US600446A
Authority: US
Inventors: William H Martin
Original assignee: Republic Industries Inc
Current assignee: Republic Industries Inc
Priority date: 1945-06-20
Filing date: 1945-06-20
Publication date: 1951-01-30
Anticipated expiration: 1968-01-30

Description

Filed June 20, 1945 INVENTOR.

WILLIAM H. MART/N ATTORNEYS fiatentecl Jan. 30,

PORCELAIN 'ENAMELED TANK William H. Martin, Lakewood, Ohio, assignor to R elilffil ib Ilfdfilil ie s, 1110., .New York, N. Y., a

corporation of Delaware Applicationtl'une 20, 1945, Serial No. 600,446

'5 Claims. 01. 29-1482) This invention relates as indicated to tanks and more especially to hot water tanks such as are used in homes and similar places for the storage of domestic hot water. More particularly this invention relates to tanks of the character described which are provided with a coating over their entire inside surface of porcelain -enamel} whereby rusting or similar deterioration of the tank is reduced to a minimum.

In the manufacture of tanks of this kind, it is necessary to separately enamel the interior surfaces of the shell and the heads which when ultimately assembled in the ends of the shell form the closed tank. This procedure of separately enamelling the three principal parts of the tank is necessary in order that such wparts may be inspected to determine the possible existence of pin holes or other minute imperfections which if present would nullify to a great extent the protection afforded by the remainder of the coat.

When the three component parts of the tank are thus enamelled prior to their assembly, they are, of course, heated to a relatively high temperature in order to fuse the enamel and fix thesame to the metal body. This heating to which the tank parts are subjected has a tendency to warp or otherwise distort the parts so that close fitting -'engagernent between :the heads and tank body is interfered with when the em amelled parts are subsequently sought to be as-' sembled. In an attempt to obviate this dithculty, it has-been proposed to make the ends of the tank and the heads coniform so that they may be assembled by a wedging action brought about by the exertion of a very considerable pressure in forcing or wedging the-coniform head into the flared or coniformed end of the tank. Thi Wedging expedient performed under high pressures will deform the warped or otherwise 2 cracking or otherwise breaking the enamel coating, but which also insures that the parts during the enamellin-g operation will be warped :to a minimum extent :so that assemblage of the component parts in close fitting relation is possible.

Other objects of the invention will appear: as the description proceeds.

To the accomplishment of. the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in claims, the following description .and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in the principle of the invention may be employed.

In said annexed drawing, the single figure is a transverse sectional view of-a -tank=constructed in accordance with the principles of my invention.

first provide a cylindrical shell generally indi- 3 cated at I which has a uniform inside diameter out-of-round parts sufficiently to bring them into proper alignment. However, in doing so, cracks are frequently developed in the enamel coating and where .a crack occurs, the contents of the tank can come .into contact'with the metal body of the tank and deterioration in such "a local area soon spreads to the point where the entire tank body has a life not substantially greater than a tank which is not provided with an enamel coating.

It is a principal object of my invention to provide a method of fabricating tanks of the character described which will not only produce component parts which can be readily assembled without pressures such as have the efiect of ameter of the body the shell is increased in from end to end. These cylindrical shells can be provided from either pierced seamless t-ubing or from 'flat sheets which are circularize'd and then welded along a longitudinally extending sea-m. Irrespective of the precise manner "inwhich these shells are provided, they will "be found to have present therein certain-stresses incidental to their fabrication, which, during the temperatures encountered in the enamelling operation, cause "the "shell to warp 'or similarly distort.

'Kfter'th'e shell of appropriate "length and inside "diameter has been thus provided, I expand each end of the shell into a cylindrical extension genera-Hy indicated at 2 which has an iriside diameter A substantially greater than the inside diameter or the main body l of the 'shell. The extension 2 iscylindricail' form. It is pro vided preferably by cold working and the diprcviding the extension 2 by an amount sufii cient to impart in set.

After the shell has been thus expanded at each end and given a permanent set in the cylindrical area 2 to a diameter slightly greater than the inside diameter of the body of the shell, the latter is then enamelled throughout the entire axial extent of its inside surface by a conventional enamelling procedure which forms no part of the present invention. It will be found that when In carrying out the process of my invention 1 such extension a permanent 3 the shell thus preliminarily formed is enamelled, it will not be warped or otherwise changed in size or shape to any material extent.

I next provide a dished sheet generally indicated at 3 which has a cylindrical marginal flange or skirt 4 with an outside diameter at least slightly smaller than the inside diameter of the cylindrical extension 2. The head 4 after being thus provided is then enamelled on its upper or inside surface, after which it is telescopically assembled in the end of the shell and maintained in assembled relation by means of a fillet weld 5 which extends around the entire periphery of the assembly. When a process such as that described above is employed, the parts may be maintained in sufiiciently closely fitting relation so that the utilization of gaskets between the head and body of the tank is not necessary.

While the shape of the dished head 3 is such that the cylindrical form of the flange or skirt is generally maintained without difficulty and without substantial variation during the subsequent enamelling operation, it is, nevertheless, also within the contemplation of my invention to include as the last forming step in the manufacture of the head 3 a radial stretching of the cylindrical flange 4 sufliciently to impart thereto a permanent set in the cold worked condition similarly to the manner in which the cylindrical extension 2 has been formed.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. The method of making a porcelain enamel lined hot water tank which comprises providing a cylindrical steel shell, expanding one end of said shell sufficiently to provide a cylindrical terminus thereon having a permanent set with an inside diameter greater than the inside diameter of said shell and joined to said shell by an abrupt shoulder, providing a head having a cylindrical marginal flange Whose outside diameter is substantially that of said shell and only slightly less than the inside diameter of said cylindrical enlargement, porcelain enamelling the inside surface of said shell and the outer surface of said flange on said head, telescopically assembling said shell and head with the latter abutting said shoulder and the cylindrical flange wall of the head in projection alignment with the cylindrical wall of the shell, and fusion welding the end of said extension to said head.

2. The method of making a porcelain enamel lined hot water tank which comprises providing a cylindrical steel shell, by means of cold working expanding one end of said shell sufliciently to provide a cylindrical terminus thereon having a permanent set with an inside diameter greater than the inside diameter of said shell and joined to said shell by an abrupt shoulder, providing a head having a cylindrical marginal flange whose outside diameter is substantially that of said shell and only slightly less than the inside diameter of said cylindrical enlargement, porcelain enamelling said shell and head, telescopically assembling said shell and head with the latter abutting said shoulder and the cylindrical flange wall of the head in projection alignment with the cylindrical wall of the shell, and fusion welding the end of said extension to said head.

3. The method of making a porcelain enamel lined hot water tank which comprises providing a cylindrical steel shell, by means of cold working expanding one end of said shell sufficiently to provide a cylindrical terminus thereon having a permanent set with an inside diameter greater than the inside diameter of said shell and joined to said shell by an abrupt shoulder, providing a head having a cylindrical marginal flange, by means of cold working radially expanding such flange to an outside diameter substantially that of said shell and only slightly less than the inside diameter of said cylindrical enlargement, porcelain enamelling said shell and head, telescopically assemblingsaid shell and head with the latter abutting said shoulder and the cylindrical flange Wall of the head in projection alignment with the cylindrical wall of the shell, and fusion welding the end of said extension to said head.

4. In the manufacture of porcelain enamel lined tanks having a cylindrical steel shell and a dished head, the steps of expanding an end of the shell out to an abrupt shoulder and a terminus of cylindrical form with inside diameter greater than that of said shell, providing a head with a marginal flange in cylinder form and outside diameter substantially that of said shell and slightly less than the inside diameter of said cylindrical terminus, porcelain enameling said shell and head, seating said head in said cylindrical terminus against said shoulder and the cylindrical flange wall of the head in projection alignment with the cylindrical wall of the shell, and welding the edges of theshell and head together.

5. In the manufacture of porcelain enamelwall of the shell, and welding the edges of the shell and head together.

WILLIAM H. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 774,041 Cofiin Nov. 1, 1904 1,748,577 Merriam Feb, 25, 1930 2,015,193 Reed Sept. 24, 1935 2,197,609 Cornell Apr. 16, 1940 2,263,021 Uecker Nov. 18, 1941 2,335,153 Lauck Nov. 23, 1943 2,363,990 Priebe Nov. 28, 1944