Three-piece can

Abstract

 The object of the present invention is to provide a can model for processed foods or not, for use by food companies or others, consisting of a three-piece can (L), which has a cylindrical shape, wherein one of the ends is expanded (neck-out), thus top (3) and bottom (4) have different diameters, but within limits not to compromise rolling on flat surfaces and guides minimizing friction between the external part of the cylindrical body with the finish or artwork while rolling. Said can may also be piled up, since it is provided with different diameters top and bottom, which fit in when stacked.

Description

[0001] The object of the present invention is to provide a can model for processed foods or not, for use by food companies or others. Said model has an enhanced construction in order to improve its use and efficiency over existing similar ones.

State of the Art

[0002] Cans for foods and other uses comprising three pieces with welded cylindrical bodies, seamed by a mechanical process at their upper ends by a top and at their lower ends by a bottom of same shape, are already known in the state of the art. Said cans may or may not be provided with rims in the cylindrical body to reinforce it, allowing the use of thin sheets.

[0003] There are two basic types for these cans:

• Three-piece cans with top and bottom of same diameter - These can are made of welded cylindrical bodies (tubes), which are calendered and welded into the final diameter of the can, then receiving conventional processes of flap formation, beading and closing the top or bottom according to clients' requirements. One example of this kind of can may be seen in Figure 1 of the state of the art.
• Three-piece cans with bigger top and smaller bottom in diameter- These are made of welded cylindrical bodies (tubes), calendered and welded in the final diameter of the can, with an additional process of diameter reduction on one of the ends of the tube (necking), then followed by conventional processes of flap formation, beading and closing the smaller diameter bottom, allowing to pile up filled cans by the difference between top and bottom diameters. One example of this kind of can may be seen in Figure 2 of the state of the art.

[0004] With the advent of sterilization in continuous rotating autoclave (cooker cooler), the two kinds of cans mentioned above have shown some unsurmountable inconveniences for their processing:

• Three-piece cans with top and bottom of same diameter - In this case, the rolling process of cans used in the continuous rotating autoclave is easily performed, and the body of the cans (tube) may be previously printed, with no loss in print quality after the rolling process. However, this solution harms the correct stacking, since the cans do not fit the others.
• Three-piece cans with larger top and smaller bottom in diameter with diameter reduction at one of the ends of the tube (necking)-These cans have the advantage of being easily piled up. The neck-in is made on the can by the hanging of one of the ends of the can whose single objective is to improve stacking. To prevent the can from rolling around its own axis due to the big difference between the top and the bottom of the can, an additional rim (reinforcement) on the body near the smaller bottom is required, so that the friction during the process may allow the can to be rolled in the continuous sterilization system without damaging the body of the can. In this case, excessive friction damages the artwork, varnish and/or tin from the body of the can at that reinforcement point. Due to this problem, the can is only labeled later on, creating additional processing steps and lowering process speed. Furthermore, due to its smaller diameter top, this kind of can is more difficult to open with conventional can openers because of the neck formed in the cylindrical body at that point to fasten the smaller top, which makes the correct placement of the opener more difficult.

Object of the Invention

[0005] Bearing the above in mind and in order to overcome the mentioned problems, the present invention has been developed. It consists of a three-piece can, with cylindrical shape with top and bottom of different diameters, wherein one of the ends goes through an expansion process (increase in diameter or neck-out), but within certain limits not to compromise its rolling on flat guides and surfaces minimizing friction of the external part of the cylindrical body with finish or artwork while rolling. Said can may also be piled up, since it is provided with top and bottom of different diameters which fit in when stacked.

[0006] This form of embodiment of the can solves the presented inconveniences, since the expanded cylindrical shape of the assembly allows for appropriate flexibility during the use, meeting various forms of use of stackable cans with the artwork already printed on the cylindrical body, especially in automatic thermal processing equipment of continous rotating type (cooker cooler) wherein rolling of the can is required. The proposed model also has the advantage of allowing the final user to open the can at any of its end with a conventional can opener, usually at the cleanest end due to the piling up.

Description of Drawings

[0007] To better visualize the present invention, the attached figures are presented as mere examples, not limiting the present application, wherein:

• Figure 1 is a partial cross section of a conventional three-piece can with top and bottom of same diameter;
• Figure 2 is a partial cross section of a conventional three-piece can with top and bottom of different diameters and reduced diameter at one of the ends of the tube (necking);
• Figure 3 is a partial cross section of a can according to the present invention, provided with an expansion of its upper part (neck out);
• Figure 4 is a view of a stack of cans of the present invention;
• Figure 5 is a detailed view of a can rolling over a flat surface, showing the lack of contact between the body of the can (tube) and the surface due to the existence of a free space (gap).

Preferred Embodiment of the Invention

[0008] The object of the present invention will be disclosed based on the above listed figures given as examples, but not limiting the scope of protection of the present invention, wherein the final can will be generically indicated as L.

[0009] The object of the present application consists of a can L, made of a welded body (1), which is initially cylindrical and which afterward has one of its edges expanded (neck-out), being said body (1) provided or not with reinforcement rims in its body (2) when the metal sheet to form the body (1) is thin.

[0010] The can L is preferably made of tinplate and/or chrome- plated steel, appropriately varnished and printed with the artwork defined by the user. The cylindrical body 1 is formed by the conventional process of plate cutting, formation of the body, calendering and welding. Initially, the body (1) is built with the base dimension (smaller), the tube is expanded at one of its ends (neck-out), the flange (flap) is formed and subsequently the rims for radial reinforcement of the can (2).

[0011] Said can L has an upper closing consisting of a conventional or easy-to-open top (3) and a conventional or easy-to-open bottom (4). Said top (3) or bottom (4) is seamed at one of the ends according to the needs of the user. When seamed, said top (3) and bottom (4) form an upper (5) and lower (6) end that support the body of the can when it is rolled.

[0012] Said ends (3, 4) have different diameters, wherein the difference between them should be comprised within a range between 2 and 6 mm. Said difference between diameters defines a range where the difference cannot be higher than 4 mm to allow the can to roll around its axis without deviation and, at the same time, allow it to be piled up. As an example, the table below shows the ratio between the diameter of the top (3) and bottom (4):

Top (3)	Bottom (4)
49	52
57	60
62	65
70	73
80	83
96	99
124	127
152	155

[0013] The can is sent to the user with one of the ends (larger or smaller) already seamed according to the client's requirements and/or tooling in the client's plant to close the cans after product filling.

[0014] If the user makes use of continuous rotating equipment (cooker cooler), the roling of the can L without harm to its body (1) is guaranteed by the support given by the upper (5) and lower (6) edges, which create a gap as shown in Figure 5.

[0015] The present invention presents several advantages to the conventional models, since the cans may be processed in continuous rotating autoclave systems (cooker cooler systems), and the cans may be stacked.

[0016] In addition, the user will not need tooling adaptations, since the closing process is conventional and the tops and bottoms used are those already abundant on the market.

[0017] The proposed can, with said construction, may be made in diverse sizes and capacities to meet different needs of users of this kind of packaging.

Claims

1. Improvement in three-piece cans, being said can (L) comprised by a cylindrical body (1) with rims (2), top (3) and bottom (4) characterized by the fact that said welded cylindrical body (1) is expanded on one of its ends and provided with a top (3) with smaller diameter and of conventional or easy-to-open type and a bottom (4) of bigger diameter, with conventional or easy-to-open type, having said top (3) and bottom (4) diameter differences of 4 mm or less between said top (3) and bottom (4) and, when seamed, they create support edges (5, 6) for the can L to be rolled on flat surfaces.

Drawing