US2190494A

US2190494A - Method of making tubular sheet material

Info

Publication number: US2190494A
Application number: US167124A
Authority: US
Inventors: Richard L Templin
Original assignee: Aluminum Company of America
Current assignee: Howmet Aerospace Inc
Priority date: 1937-10-04
Filing date: 1937-10-04
Publication date: 1940-02-13
Anticipated expiration: 1957-02-13

Description

Feb. 13, 1940. TEMPMNv 2,190,494

METHOD OF MAKING TUBULAR SHEET MATERIAL Fil ed Oct. 4, 1937 INVENTOR. R/cr/A RD L. TEMPL/N.

Patented Feb. 13, 1940 PATENT OFFICE METHOD OF MAKING TUBULAR SHEET MATERIAL Richard L. Templin, New kensington, Pa., assignor to Aluminum Company of America, Pittsburgh, Pa.,' a corporation of Pennsylvania Application October 4, 1937, Serial No. 167,124

5 Claims.

This invention relates in general to the production of hollow or tubularjsheet or plate material. In particular, and in its preferred form, the invention relatesto the production of a rela 5 tively thin sheet metal product provided with internal tubular apertures.

There is an ever increasing demand for tubu lar structural material in sheet form which is adaptable to the construction of fluid circulating systems, such as heat exchange systems, heat radiating systems, refrigeration systems, hot plates and the like. For such purposes, it has been known to employ built-up units from individual tubes provided with fins, or relatively heavy cast units, wherein wrought tubular members are incorporated in a cast metal body structure, most, if not all of which, have incorporated in their construction complicated, soldered, and

' welded joints.

:0 It is an object of the present invention to overcome the necessity of resorting to complex and cumbersome constructions, as well as units "comprised of two or more dissimilar metals, in the manufacture of units and devices requiring is internally apertured material, by providing a metal product in stock form from a single alloy or composition, and in quantities from which the numerous devices in question may be constructed. It will be manifest that the sheet ma- 0 terial of this invention will'be representative of a monometallic sheet product which is of greatly reduced weight per unit of length, and will therefore adapt itself to structural uses other than those specifically mentioned herein.

5 Other objects, including maximum economy of material and labor, represented by this invention will be apparent to those skilled in this art on consideration of the following description taken in conjunction with the drawing, in which:

V Figure 1 illustrates a top planview of a slab or blank of initial or starting material;

Figure 2 illustrates "an end view of the slab represented in'Figure 1;

Figure 3 illustrates an end view of the slab 5 represented in Figure 1 at an intermediate stage in the production of,the final-product of theinvention;

Figure 4 illustrates an end view of the preferred final product of the invention; and

| Figure 5 illustrates-a modified form of the final product of the invention.

when described in its most general terms. the

invention comprises subjecting an initial blank or slab of material, having one or. more internal tubular-apertures, to a working or series of progressive working operations to partially or completely, dimensionally transform the initial slab. This starting or initial material may be produced in any suitable manner, such as by extrusion, permanent mold casting, die and/or 5 pressure casting, or sand casting. The initial slab is preferably of thicker -gauge, or wider dimension than that finally desired, and in its preferred form is provided with an excess of metal or protuberance adjacent-an internal apertime on opposite exterior faces of lthe initial blank. In some instances, however, a single protuberance adjacent the internal aperture and disposed on the exterior face of the blank or slab may be sufiicient for the purpose of this invention. An initial blank of either of the forms afore-described is finally subjected to any suitable working operation, such as rolling,

' drawing through a die, or the like, to dimensionally transform, or completely obliterate, the excess metal and. transform the blank to one having the required final form. It will be understood that, in the preferred embodiment of the invention, any further reduction of gauge, following obliteration of the excess metal, will elongate the slab to sheet proportions with an attendant further transformation in the shape and size of the internal aperture or apertures,

it being possible, and in most instances desirable, to reduce the wall thickness of an aperture, as measured in the plane of the gauge of the worked sheet material, to a point which could not otherwise be accomplished by any known means of manufacture. The original slab being thicker than that usually required in the 5 final preferred product, allows for greater ease in producing the internal apertures in the initial slab, and the subsequent working imparts the desirable characteristics attributable to a cold and/or hot worked product. Also, where the metal of the blank is only subjected to a partial dimensional change, the same advantages willbe obtained.

Referring specifically to the .illustrations represented in the drawing accompanying the speci- 5 fication, Figure 1 represents a slab of material III in plan view, provided with longitudinal aper-. tures H extending throughout the length of the slab. This'slab may be cast or produced by extrusion, the-latter process of production being '50 preferred when it is desired to produce the novel Product of this invention from non-ferrous metals, and particularly from aluminum and its alloys. The extrusion process lends itself readily to accuracy in dimension and duplication of production with a minimum of labor and tools, anddisplaced with an attendant reduction in the apertures ll do not necessarily extend throughout the length of the product of the initial blank I0, where methods of manufacturing the initial blank are distinguished from a strictly extrusion operation.

Figure 2 illustrates an end view of the initial slab or bloom. From this view, it will be noted that the internal apertures II are circular in cross section, and that excess metal is provided in the formof protuberances l2 adjacent each aperture and disposed on opposite sides of the initial slab or blank along the plane of the gauge of the blank. This excess metal serves to reinforce the aperture during the production of the initial slab, distribution of the metal adjacent the apertures insuring complete filling out of the slab or bloom, if extruded, and likewise insuring suflicient support for cores, or the like, if a casting operation is resorted to in the production of the initial material. Also, the excess metal l2 serves to equalize the stresses inherent in the initial slab Ill, regardless of its method of production, and permits a much larger original aperture H. with its attendant 'ease in production, than thatfinally required or desired. Although the apertures II have been illustrated as circular in cross section, in the original slab or bloom, it is to be understood that these internal apertures may take any desired or suitable cross sectional configuration, with equally successful results in the further practice of this invention.

Figure 3 illustrates an end view of slab l0 following a working operation, such as a progressive rolling or die drawing operation,vand

represents a form of the product of the inven-' tion at an intermediate stage in its production. It is to be noted thatthe protuberances l2 have been reduced in thickness, as measured in the plane of the gauge of the material, and that the apertures II have become slightly elliptical or'lenticular in cross section with only an appreciable change in major axial dimension. The cross sectional transformation of the apertures II will be manifest when it is considered that the directional rolling elongates the initial slab it without any appreciable change in width of the initial slab or blank.

In Figure 4, the protuberances or ribs 12 have been completely obliterated and progressively worked or rolled into the surface of the slab I0,

and the apertures II have reached their final cross sectional form. Further rolling will serve to reduce the gauge of the slab I0 and reduce the wall thickness of the apertures H, as measured alongthe gauge line of the slab. This condition is often desirable, particularly when the product of the invention is to be used in the subsequent construction of heat exchange equipment, since ready transfer of heat is a functionof the rate of transfer of heat through the wall thickness of the tubular product. t

Figure" 5 illustrates a modified form of end product which can be produced from the original 'or initial blank III, in accordance with the practice of this invention. In this embodiment of the invention, the slab or blank I0 is subjected to a working or series of working operations, such as by die drawing or edge working, whereby the metal of the protuberances I2 is laterally overall width of the initial blank. As a result of this type of working, the protuberances 12 are decreased in'width and increased in height, while the apertures II are transformed to elliptical or lenticular' cross section with their major axes in the vertical plane.. Manifestly, the working operations could be performed in a manner to produce a final product in which'the major axes of the apertures II and the disposi-- tion of the protuberances I! would be angularly disposed'if desired.

From the above general and specific description and explanation, it will be appreciated that the process and product of this invention have eliminated cumbersome .forming, machining, welding, and other operations of like character now known to this art. It will alsobe understood that the invention makes it possible to produce a stock product in wrought sheet form which may be cut into lengths and employed in any number of constructions. The tubular sheet product of this invention readily adapts itself to forming operations, and wherever light-. ness in weight, for a given thickness, but an otherwise plane surface is required, the product herein described as the preferred form of the -invention (Figure 4) finds ready adaptability.

. fore, the exact form shown is to be taken as illustrative only and not in a limiting sense, and it is desired that only such limitations shall be placed thereon as are imposed by the prior art, or are specifically set forth in the appended claims.

What I claim is:

1 The method of producing an apertured metal product comprising the steps, extruding a blank having an internal aperture and an excess of metal of uniform cross section coextensive with, adjacent and exterior to the aperture as measured in the plane of the gauge of the blank, and subsequently submitting the excess metal to a progressive rolling operation to uniformly displace the same and simultaneously change the cross sectional configuration of the internal aperture, said blank being interiorly unsupported during the rolling operation.

2. The method of producing an apertured metal product comprising the steps, extmding a blank having an internal aperture and an excess of metal of uniform cross section coextensive with, adjacent and exterior to the aper ture as measured in the plane of the gauge of the blank, and subsequently submitting the blank to a progressive rolling operation to obliterate the excess metal and simultaneously change the cross sectional configuration of the internal aperture, said blank being interiorly free from support within said aperture during the rolling operation.

3. The method of producing an apertured product comprising; the steps, extruding a blank having an internal aperture and an excess of material of the blank of uniform cross section coextensive with, adjacent and exterior to the aperture as measured in the plane of the gauge -of the blank, and subsequently submitting theblank to a progressive rolling operation to uniformly displace the excess material and simultaneously change the cross sectional configuration of the internal aperture, said blank being interiorly unsupported during the rolling operation.

4. The method of producing an apertured wrought sheet metal product comprising the steps, extruding a blank having an aperture extending into the interior thereof and an excess of metal of uniform cross section coextensive with, adjacent and exteriorto the aperture in the plane of the gauge of the blank, and thereafter subjecting the blank to a progressive rollsimultaneously changed, the blank being interiorly free from support Within said aperture during said rolling operation.

5. The method of producing an apertured metal product comprising the steps, extruding a blank having an internal aperture and an excess of metal coextensivev with, adjacent and exterior to the aperture as measured in the plane of the gauge of the blank, and subsequently submitting the blank to a progressive rolling operation to obliterate the excess metal and simultaneously change the cross sectional configuration oi the internal, aperture, said blank being interiorly free from support within said aperture during the rolling operation.

RICHARD L. TEMPLIN.