Manufacture Of Cans And The Like

Abstract

This application discloses a novel process in the manufacture of two-piece metal cans and the like wherein a predrawn cup is produced at the mill rather than by the can manufacturer. The predrawn cup is flanged and tapered. The predrawn cups are stacked in nested relation and a plurality of stacks are packaged at the mill for shipment to the can manufacturer. The can manufacturer then need only redraw and wall-iron the cups and trim, flange, wash and decorate them in order to complete the manufacture of the can. By this procedure scrap loss to the can manufacturer is avoided, making it also easier for a manufacturer to enter the can manufacturing business with less capital investment.

Description

BACKGROUND OF THE INVENTION

The conventional way in which so-called two piece cans are manufactured is that the can manufacturer buys his basic material from a mill in the form of a coil. From this coil the can manufacturer cuts out circular blanks and by means of a press operation produces a so-called first operation cup. This cup is then redrawn and wall-ironed in order to achieve the full container height. The cans are then trimmed, washed, necked and flanged so as to be ready for use.

In this procedure, the can maker must invest in an initial blanking and drawing press and tooling which represents a substantial investment which makes it expensive to get into the can making business. Additionally, it has been found that approximately seventeen percent of the coil stock fed into the blanking and cupping operation results in scrap which must be returned to the metal supplier. This seventeen percent scrap material is paid for by the can maker at the full price of the metal coil but when it is sent back in the form of scrap, he recoups only a fraction of what he paid for it. This results in a substantial loss to the can maker.

According to the present invention, the basic metal supplier will cut the blanks and draw the blanks into cups, the cups so drawn will be flanged and tapered so that they may be nested for shipment. At the mill, a plurality of such flanged and tapered cups will be stacked in nested relation and a plurality of stacks will be packed in containers for shipment to the can manufacturer. According to the present method, scrap at the can manufacturer's plant is substantially eliminated.

Flanged and tapered cups as a finished article of manufacture are known in U.S. Pat. No. 3,248,003 to Henchert. The cups there disclosed are finished articles ready for filling and closing. According to the present invention, the flanged tapered cups are intermediates and are only tapered for convenience in shipping in order to improve the space factor of the shipment. In the formation of predrawn cups, it is not ordinarily necessary that such cups be tapered and in fact tapered cups have never been used to applicant's knowledge in the manufacture of cylindrical cans.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a plan view of a blank in which a can or the like is to be formed.

FIG. 2 is a diametral cross sectional view of a first operation cup according to present practices.

FIG. 3 is a similar view after the cup has been redrawn and wall-ironed to produce full can height.

FIG. 4 is a similar view showing the can body after it has been trimmed, necked and flanged.

FIG. 5 is a diametral cross sectional view of a first operation according to the present invention.

FIG. 6 is a similar view of the completed predrawn cup ready for shipment to the can manufacturer.

FIG. 7 is a similar view after the predrawn cup has been redrawn and wall-ironed to full height.

FIG. 8 is an elevational view of a plurality of predrawn cups according to FIG. 6 in nested relation.

DETAILED DESCRIPTION

According to the present invention, the basic metal supplier, instead of shipping a metal coil to the can maker, will blank out blanks such as the circular blank 10 of FIG. 1 and will draw them in either one or two steps until they assume the configuration of the cup 11 of FIG. 6 having the flange 12.

In order to achieve the cup of FIG. 6, it may be necessary to go through a first draw to produce the configuration of FIG. 5 wherein a small taper is provided at 13, the balance of the cup being cylindrical as at 14. In going from the configuration of FIG. 5 to that of FIG. 6, the tapered walls are straightened out to a taper of about not more than 9.degree. and the flange 12 is provided.

A plurality of the cups of FIG. 6 which constitute an intermediate in the manufacture of two-piece cans and the like are nested together as indicated in FIG. 8. A plurality of stacks according to FIG. 8 are then packaged in a suitable container which may be palletized for ease in handling and this container is then shipped to the can manufacturer.

Thus, in addition to producing the metal coil, the basic metal supplier will now blank the blanks from the coil and predraw the tapered flanged cups of FIG. 6 and will stack them and package them, containerize them and palletize them for shipment to the can maker.

Heretofore, the basic metal supplier has merely produced a coil of metal which he has shipped to the can maker. The can maker has then formed a cup 15 as shown in FIG. 2 and has then redrawn and wall-ironed the cup to its full height to the configuration shown at 16 in FIG. 3. He has then trimmed, washed, decorated, necked and flanged the can so that the can is ready for use as shown at 17 in FIG. 4.

It will be observed that the steps of the present process are basically the same as those of the prior art except that the producing of the predrawn cup is transferred from the can maker to the mill and in order to make possible the shipment of the predrawn cups with an economically sound space factor, the cups are produced in tapered form as shown in FIG. 6. The predrawn cups in the manufacture of two-piece cans have always been as shown in FIG. 2 and there has been no reason and there is no reason in the manufacture of these cans to provide tapered cups. However, the provision of the tapered cups makes possible the convenient shipping of the predrawn cups from the basic metal supplier to the can maker.

The process herein disclosed avoids the production of scrap at the can maker's plant, which scrap must then be shipped back at substantial loss to the basic metal supplied. The process also greatly reduces the initial investment which must be made by one seeking to enter the can making business. While the basic metal supplier must make an investment in blanking and drawing presses and in packaging apparatus, this investment will make it easier for him to interest manufacturers in two-piece can manufacturing business. The basic metal supplier can very readily dispose of the scrap by conveying it from the blanking operation to the furnace for remelt. This assures minimum contamination of scrap material which usually occurs when reclaiming scrap returned to the metal supplier from the conventional process. Thus, the present process is economically sound and is of advantage both to the basic metal supplier and to the can manufacturer.

Modifications may of course be made without departing from the spirit of the invention and therefore no limitation which is not specifically set forth in the claims is intended or should be implied.

Claims

1. In the manufacture of cans and the like, the steps, performed at the mill, of

a. cutting circular blanks from a coil or the like of sheet metal;

b. drawing said blanks into smoothly, tapered and outwardly flanged cups;

c. stacking numbers of said predrawn cups into nested stacks;

d. packaging a plurality of said nested stacks for shipment; and

e. shipping said package to a can manufacturer; and the steps performed at the manufacturer's plant of

f. redrawing and wall-ironing said predrawn cups to full can dimensions and

g. trimming, flanging, washing, and decorating said cans.