US2299090A - Container and method of producing the same - Google Patents

Description

1942- J. M. HOTHERSALL CONTAINER AND METHOD OF PRODUCING THE SAME Filed Dec. 31, 1938 drawing, discloses Patented Oct. 20, 1942 I UNITED STATES P A'lENT OFFICE CONTAINER AND ME 'rnn THOD OF PRODUCING SAME John M. Hothersall, Brooklyn, N. Y., asslgnor to American Can Company, New York, N. Y., a corporation of New Jersey A plication December a1, 1938, Serial No. 248,846

3 Claims.

as certain automobile polishes wherein electro1- ysis .of the can wall means impairment of the contents.

It is well known that the use of aluminum and aluminum alloys in cans when in electrical contact with the can wall prevent deposition of the objectionable iron salts in certain contents of cans as suggested in the J. H. Perkins Patent 1,958,765, issued by the United States Patent Oflice on May 15, 1934.

The present invention contemplates the use of a suitable metal or metals which are higher in the electro-chemical series than the .iron and the tin of the commercial tin can and which function as an anodizing agent and the invention is directed to an improved manner of providing such anodic metal in the can wall during manufacture of the can so that an'inside can coating inert to the can contents may 'be used and so that the ordinary processes of can manufacture properly condition the can for its intended use.

An object of the invention is the provision of a method of producing a. metal can which is constructed so as to be electrolytically protected against decomposition of the metal of the can when used with contents which provides an electrolyte for promoting an electrolytic action between the can and the contents.

Another object is the provision of such. a

method of protecting the can against electrolytic decomposition by the use of an anodic rivet electrically coupled with the can wall.

A further objectof the invention is the provision of a method of the character described wherein the can during its manufacture is coated with a suitable lacquer or other inert coating material, the steps of such manufacture conditioning the anodic rivet for eifective use when the can is filled and sealed.

Numerous otherobjects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying a preferred embodiment thereof.

Referring to the drawing:

Figure 1 is a perspective view of a can body blank from which a can is made in accordance with the' instant method invention, the view also showing an anodic rivet in place therein;

Fig. 2 is a sectional view of one form of apparatus usedfor inserting the rivet in the blank, the view showing a blank receiving itsv rivet;

Figs. 3 to 6, inclusive, are perspective views showing different stages in the transformation of the flat blank into a formed tubular can body;

Figs. '7 to 10, inclusive, are sectional views of suitable apparatus for effecting the transformation of the flat blank into a tubular can body and showing the blank being operated upon;

Fig; 11 is a sectional view of one end of the body showing how the flanges are shaped;

Fig. 12 is a sectional view of suitable apparatus for flanging the can body, the view showing a body being flangedat one end;

Fig. 13 shows the step of coating the interior of the can body;

I l-illustrates the step of closing one end of the body; and

Fig. 15 is an enlarged sectional detail of one corner of the closed can, the view illustrating the anodic rivet and its relation to the other parts of the can. l

As apreferred embodiment of the instant method invention the drawing illustrates a fiat can body blank 2| (Fig. 1) which is adapted to be formed into a cylindrical can body and which 'is closed with end closures after filling in accordance' with the instant method steps, The blank is preferably rectangular in shape and is 'provided with the usual clipped corners 22 and slits 23 which set off side seam lock sections 24 and lap sections 25 in the short edges of the blank.

An anodic rivet 21 is used and may be made of any metal higher in the electro-chemical series than the iron, steel or tin of the can pro- .vided such metal is suitable for the product being packed. Aluminum, zinc, manganese or alloys ofthese metals are generally suitable for food products.

Rivet 21 has a head 28 and a shank 29 (see also Fig. 15) and is inserted in the flat blank in a position adjacent one of the longedges of the blank so that it will be partially incorporated in the bottom end seam when the can is closed as will be hereinafter explained.

The rivet may be inserted in any suitable manner as by a. punch 3| and a die 32 (Fig. 2) the blank 2| having been properly prepared to receive the rivet.

The flat body blank is curled or otherwise formed into tubular can body shape in a conventional manner such as by passing between a pair of rotating rollers 34 which feed the blank against a deflecting plate 35 disposed adjacent the rollers. The curled partially formed can body (now referred to by the numeral 36) may be received on a horn or mandrel 31 along which it is advanced for furthertreatment.

After the shaping step the side seam lock sections 24 of the partially formed can body 36 are edged in the usual manner to produce oppositely directed side seam hooks 39 as shown in Fig. 4.

. This edging or bending operation is usually performed while the partially formed can body is on the mandrel 31. The side seam edges of the body project adjacent a recess 4| (Fig. 8) formed in the mandrel and are bent by moving edging irons 42' against stationary edging steels 43 seated in the mandrel and also against movable clamping steels 44 which clamp the blank in place while being edged. The edging irons 4| are secured in a rocking shaft 45 which is operated in any suitable manner.

While on the mandrel 31 the hooked edges 39 of the body 36 are interengaged as shown in Figs. and 9 by a pair of movable wings 41. The wings hold the body against the mandrel while a bumping hammer 48 squeezes the hooks together in an interlocked side seam 5! as shown in Figs. 6 and 10. This is a regular can body forming operation, the seam completing the formation of the body now indicated by the numeral 52. If desired the seam may .be soldered in accordance with usual can making practice.

The formed can body 52 is now removed from the mandrel 31 and both of its end edges are bent outwardly into flanges 5 3. One end is so shown in Fig. 11. This flanging may be done in a conventional manner as in a flanging head 55 (Fig. 12). Obviously there will be two flanging heads'both working together. Such a head is pressed against the end edges of the body, the

body fitting into and being gaged by a groove 56. This turns the metal of the body outwardly as the head moves in.

As the next step in producing the can the flanged body 52 is interiorly covered with a corrosive resistant coating material which may be one or more coats of such lining material as is now used so extensively in can manufacture. Such coating material may be sprayed on the inside of the can body with a spray nozzle 58. This spraying operation covers the entire inside of the body, including the flanges and the rivethead 28 with a coating 59. Coating of the rivet head is not desired as'far as its use as an anodic rivet is concerned, but in high speed production it is next to impossible to prevent such covering. This will be again referred to. The coating step may be omitted for some products.

The body is now prepared to receive a bottom end closure 6| to condition it for filling. After the can is filled it may be sealed with a top end closure to make it ready for shipment. side surfaces of these end closures are also provided with a coat 62 of the same coating material as the body coat 59 where this coating step is used.

.The completed can before it is filled will first be considered and referring now to Fig. 15 it will a be noted that the position of the rivet 21 in the body is such as to bring its head 28 adjacent and in contact with aportion of the bottom closure 5 i A portion of the rivet head also extends above the closure and is exposed to the inside of the can. This will be explained.

During the step of seaming the cover onto the can any coatingis broken back from the rivet head leaving it exposed. It is thus conditioned to function as an electric anode for the purpose hereinbefore stated. In this seaming step the closure is secured to the can body by an interfolding of a curled flange 53 of the closure with the flange 54 of the body. This is a regular double seaming operation done by two or more rollers. A seaming roller 65 is indicated in Fig. 14 as exemplary of this step.

The inis the pressure and strain upon the metal exerted during the formation of this seam which rubs the rivet head 28 against the adjacent wall of the closure and breaks through and scrapes off the undesired coating fromboth the rivet head and the engaging part of the closure. This completes the making of the can which it will be observed is standard can practice with the. exception of the inclusion of the rivet and although a part of the procedure renders the rivet impotent as an anodic member further necessary steps in the can manufacture conditions the rivet for its ultimate use.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the steps of the process described and their order of accomplishment without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the process hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. The method of making metal cans for holding without impairment contents adversely affected by electrolysis, comprising providing a metallic can body member and a metallic end member for closing said can body member, one of said members having an anodic rivet projected therethrough in a predetermined location; coating the interior of the can body member and the interior surface of the end member including the exposed surface of said rivet; and securing said members together in an end seam so that said anodic rivet is partially enclosed in the seam, the forming of the seam breaking the coating on the rivet and also the adjacent coating on one of the members so that said rivet and metallic member are partially exposed for contact with the can contents when the can is filled. 2. The method of making metal cans for holding without impairment contents adversely affected by electrolysis, comprising providing a metallic can body member and a metallic end memher for closing said can body member, said bod: member aving an anodic rivet projected therethrough in a predetermined location; coating the interior of the can body member and the interior surface of the end member including the exposed surface of said rivet; and double seaming said members together in an and joint so that said anodic rivet is partially enclosed in the seamed joint, the forming of the seamed joint breaking the coating on the rivet and also breaking the adjacent coating on one of said members so that said rivet and metallic member are partially exposed for contact with'the can contents when the I can is filled.

3. A sheet metal can for holding without impairment contents adversely affected by electrolysis, comprising a metallic can body member and a metallic end member for closing the same, one of said members having an anodic rivet projected therethrough in the region'of the end seam. said members having an interior coating material thereon covering also a portion of therivet surface, said body and cover members being secured together in an end seam, the coating on said rivet and adjacent surface of one of said membersbeing partially broken so that said rivet and metallic member are partially exposed for contact with the can content when the can is filled.

. JOHN w1V1. HOTHERSALL.

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