US2754581A - Method of producing ornamental metallic sheets - Google Patents

Description

July 17, 1956 E. P. THOMAS 2,754,581

METHOD OF PRODUCING ORNAMENTAL METALLIC SHEETS Filed Jan. 21, 1954 INVENTOR, EUGENE/q THOMAS ATTORNEYS.

UnitedStates Patent "cc METHOD OF PRODUCING ORNAMENTAL METALLIC SHEETS Eugene P. Thomas, Kenmore, N. Y., assignor to Rigitlized Metals Corporation, Buffalo, N. Y.

Application January 21, 1954, Serial No. 405,449

6 Claims. (Cl. 29-556) This invention relates to anovelmethod or process of producing ornamental or decorative metal sheets.

An object of the present invention is to provide a pracheal and economical method ofproducing metallic sheets having the surface appearance of a basket weave wherein flat bands of material are interwoven atright angles to each other in a. familiar woven pattern To produce such an ornamental surface appearance in a unitary metallic sheet has heretofore been. impractical since, to carry out the design and produce ametallic sheet having the proper appearance, it is necessary to form: perforations in the sheet to simulate theusual openings between the lacings in basket weave material. These openings'occur adjacent to the intersections of the edges of the simulated bands of material. In addition it is essential to provide the necessary surface embossment whichmust be provided on the sheet of metal to simulate the usual woven bands in basket weave material which. have just been referred to.

To produce these perforations by the usual perforating punch and die method which cuts a clean and complete hole in the material is impractical because of the force required to produce a practicallyv sufficient number of per forations in a single punch. and die assembly, because of the extreme accuracy required. in perforating punch and die operation, and. because of the impracticalit'y of producing such perforations by a continuous rolling process.

The present inventionprovidesa roll process, employing a pair of mated or matched male and female embossing rolls, which forms piercedv openings in the sheet simultaneously with the formation of the desired basket weave surface embossments. The pierced openings formed in this manner leave jagged prongs at one face of the sheet but the arrangement is such that. these jagged prongs occur at locations on one face of the embossed sheet which protrude farther from the general plane of the sheet than other portions of the surface. The subsequentstep of the presentmethod involves abrading the surface of the sheet containing thejagged projections and this abrasion step eliminates the-jagged projections readily and without reaching the general surface of the sheet with the abrasions means.

Speaking generally, the basket weave embossments comprise crossed lines extending at right angles to each other generally over the sheet in such fashion that the embossed crossing lines occur as grooves on the prime or obverse side of the sheet and as ridges on the reverse side of the sheet. The jagged projections formed by the piercing portion of the roll-forming operation project from the reverse side of the sheet and occur at the intersections of the crossing ridges formed by the embossment so that, in effect, each jagged projection sets upon an embossed prominence on the reverse side of the sheet.

This renders the jagged projections readily accessible to a surface abrasion operation which is sure to reach and remove all parts of the jagged projections without reaching the general plane of the reverse surface of the sheet, despite surface irregularities which are unavoidable in practical operation of a roll-forming embossing method of the kind here contemplated.

By reason of the foregoing fabricating method the embossing and piercing may be carried on more or less simultaneously as the result of a single roll forming and piercing operation by the use of male and female mating rolls carrying the desired basket weave embossing formations, in the form of complementary grooves and ridges, and the piercing formations, the latter comprising piercing punches on one of the rolls and suitable receiving perforations on the other. As indicated above, the crossing lines are embossed or depressed into the front face of the sheet. The piercing punches likewise enter the sheet from the front face at the line intersection and accordingly the prong formations resulting from the piercing project from the rear face of the sheet at the most prominent or most protruding portions thereof, namely at the embossed line intersections, as suggested above.

it is accordingly merely necessary to apply surface abrading instrumentalities of any desired type to the rear face of the sheet as by passing the same beneath a conventional abrading belt to abrade such rear face or, more properly, the piercing projections thereof, until the prongs are removed and the rear surface of the sheet is reduced to the plane of projection of the embossed crossing lines.

The following description and the accompanying drawing set forth apparatus and a specific process for accomplishing the purposes of the present invention but it is to be understood that the details thus set forth are by way of example only and that many mechanical variations and modifications may be introduced without departing from the principles of the method of the present invention which is limited only as defined in the appended claims.

In the drawings:

Fig. 1 is a schematic elevational view of a pair of matched embossing and piercing rolls for performing the multiple first step of the process of the present invention in the exemplary form here set forth;

Fig. 2 is a schematic elevational view of a belt abrading apparatus for removing the jagged projections formed by the piercing of the sheet;

Fig. 3 is a fragmentary view of the embossingand piercing rolls on a larger scale;

Fig. 4 is a perspective view showing the reverse side of the work sheet after the embossing and piercing step has been performed;

Fig. 5 is a view similar to Fig. 4 but showing the reverse side of the work sheet after the abrading step of removing the jagged projections has been performed; and

Fig. 6 is a perspective view of the prime or obverse side of the finished sheet showing the complete basket weave formation thereof.

Like characters of reference denote like parts throughout the several figures of the drawing and; referring particularly to Figs. 1 and 3, the numerals 10 and 11 designate upper and lower mated or matched embossing and piercing rolls which are supported and driven in conventional manner, a work sheet passing between the rolls being designated 12. The matched grooves and ridges of the rolls which form the embossed portion of the basket weave pattern do not appear in Figs. 1 and 3 but comprise ridges on the roll 10 which have complementary or matching grooves in the surface of roll 11.

One set of ridges and grooves of the rolls 10 and 11, respectively, extend along spaced lines which are parallel to the axes of the rolls, comprising transverse grooves and ridges, while the other set of grooves and ridges extend peripherally of the rolls, parallel to each other, to form the longitudinal grooves and ridges of the embossed sheet.

The grooves and ridges are intermittent in form. Thus, in Figs. 4 and 5 intermittent longitudinal ridges 13 are more or less connected by ridges 14 while intermittent Patented July 17, 1956- transverse ridges are again more or less connected by ridges 16.

At the enclosed intersections thus formed by the various intermittent transverse and longitudinal ridges of the upper embossing roll 10 there are provided protuberances 18 which interfit with complementary recesses 19 in the surface of the lower roll 11. The protuberances 18 are tapered in form as shown in Fig. 3 and fit into the recesses 19 in roll 11 with sufiicient clearance to produce pierced openings with the aforesaid projections 17.

It is believed to be clear from the foregoing that these pierced openings which are formed in the work sheet are not the usual perforations wherein the slug of material is completely removed from the perforated hole. As clearly shown in Fig. 4, the piercing operation performed by the projections 12 and recesses 13 leaves the stock pierced from the sheet still attached thereto in the form of the jagged projections designated 17 in Fig. 4. These projections are of random shape and not as regularly disposed as indicated in the drawing but in any event the projecting portions all extend from the reverse face of the work sheet entirely beyond the more or less elevated plane formed by the intersecting ridges which occur on such reverse face of the sheet as a result of the embossing operation described hereinbefore.

The total force required, and also the accuracy required in matching the piercing punches and recesses of the rolls 10 and 11, are very much less than would be required to perforate complete openings in the sheet, and of course the complication of arranging for slug removal in gang perforating apparatus is eliminated. Thus the combined embossing and piercing operation performed by the rolls 10 and 11 may be carried on continuously and without undue loading of the rolls themselves or the rolling machinery. Furthermore, the tolerance afforded in the piercing operation performed by the rolls 10 and 11 permits the manufacture of the rolls within economic limits and avoids undue maintenance costs which would be prohibitive in sharpening and replacing perforating punches in conventional perforating punching apparatus.

Moreover, the ultimate result is superior to ordinary complete perforation and slug removal, since a certain amount of burring at the female die side of ordinary perforated holes is inevitable. The abrading step of the present method leaves the margins of the openings 20 at reverse side of sheet 12 clean and smooth with no sharp projections.

This final abrading step may be accomplished in various ways. Fig. 2 shows a belt abrading apparatus 21 between which the embossed and pierced work sheet 12 is passed to remove projections 17 and leave the reverse side of the work sheet in the final finished form shown in Fig. 5.

What is claimed is:

l. A method of producing an open-work ornamental metal sheet comprising rolling the same between mating embossing rolls to form a plurality of intersecting grooves at one face of the sheet with corresponding intersecting ridges at the other face, substantially simultaneously pierc- 4 ing the sheet at the intersections of the grooves to form barbed projections at said other face at the ridge intersections, and subjecting said other face to surface abrasion to a degree sufiicient to remove said barbed projections.

2. A method of producing a basket-weave-simulating metal sheet comprising rolling the same between mating embossing rolls to form a plurality of intersecting grooves at one face of the sheet with corresponding intersecting ridges at the other face, substantially simultaneously piercing the sheet at the intersections of the grooves to form barbed projections at said other face at the ridge intersections, and subjecting said other face to surface finishing to remove the barbed projections from said ridge intersections.

3. A method of producing an open-work ornamental metal sheet which comprises forming a plurality of intersecting grooves at one face of the sheet with corresponding intersecting ridges at the other face, substantially simultaneously piercing the sheet at the intersections of the grooves to form barbed projections at said other face at the ridge intersections, and subjecting said other face to surface abrasion to a degree sufficient to remove said barbed projections.

4. A method of producing a basket-weave-simulating metal sheet which comprises forming a plurality of intersecting grooves at one face of the sheet with corresponding intersecting ridges at the other face, substantially simultaneously piercing the sheet at the intersections of the grooves to form barbed projections at said other face at the ridge intersections, and subjecting said other face to surface finishing to remove the barbed projections from said ridge intersections.

5. A method of producing an ornamental metal sheet comprising rolling the same between mating embossing rolls to form a plurality of intersecting grooves at one face of the sheet with corresponding intersecting ridges at the other face, piercing the sheet at the intersections of the grooves whereby projections are formed at said other face at the ridge intersections, and subjecting said other face to surface finishing to remove said projections from said ridge intersections.

6. A method of producing an ornamental metal sheet which comprises forming a plurality of intersecting grooves at one face of the sheet with corresponding intersecting ridges at the other face, piercing the sheet at the intersections of the grooves whereby projections are formed at said other face at the ridge intersections, and subjecting said other face to surface finishing to remove said projections from said ridge intersections.

References Cited in the file of this patent UNITED STATES PATENTS 2,004,747 Daly June 11, 1935 2,138,625 Colby Nov. 29, 1938 2,218,674 Eaton Oct. 22, 1940 2,223,768 Martin Dec. 3, 1940

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