Method of assembling the thin sheets tools for carrying out the method and articles.

AS AFRICAN AND MALAGASY

INDUSTRIAL PROPERTY

P. 887

In Yaounde (Cameroon)

the R - VBE1

THE O. THE A. M.>W

Patent International Patent Classification:

19 November 1966 request

the OAMP.I. (no. 52663 G.P.

21 - B 29 NO. 02279 B.

9 hr 40 min to

) by

Company said: corporaton CENTEALE packages aluminum "CEBAL", residing in FEANCE

5 May 1970 delivered

Official ballot dei970 publishes at no. 1

PRIORITY:

Patent application deposited under the no. 39112 FEANCE

19 november 1965 on behalf of the applicant.

A process for joining thin sheets

Tools for carrying out the method

and objects made.

The present invention relates to a method for the assembly of thin sheets, toolings fear implementing this method and articles made from.

The method is applicable to any material sheets born babies:

metal " alloy, complex, and same plastic materials soften point slow. high enough.

It is known of collating the P " R-crimping, _V. i->R. welding, or by on. relieves a plastic ring on the edges to be joined.

Crimping involves delicate point - located.

T-•relatively complicated equipment j-it applied incorrectly in the case of very thin foils.

The welding assumes the implementation of automatic machines expensive and very careful preparation of b joint areas; it allows only rates quite limited, so that it is necessary to multiply the welders.

The direct overmolding, which enables the assembly of thin sheets, requires however, as well as welding, the use of automatic machines costly work cycle of relatively long. Finally, the need to orient the jet of plastic in a direction strictly determined relative to the wafer sheets, throughout the duration of the injection, provides a difficult problem.

The object of the present invention is a method for assembly of thin sheets, which implements only simple machines, allowing a high production rate and achieving a positive seal assembly. Y

The L * - invention also relates to a tool for carrying out this process.

The invention also discloses the objects made by implementing the method and tooling.

In the method according to 1 * invention, a preform made of thermoplastic material, whose section has an angle at least equal to a right angle and whose shape around. 6 * adapte, sheets to be joined, is heated up to a temperature adequate to * good shaping, and then made on the sheets to be joined, finally folded over onto the sheets in a tooling comprising basically two elements substantially surrounding and in susceptible close on the sheets by bringing with pressure of said two members.

The tooling according to the invention comprises, in the case where the section of the blank has a substantially right angle:

- on the one hand, a first member that has at right joint providing a work surface peripheral representing the section to give the portion of the seal comes into contact therewith;

- on the other hand, a second member including a concave terminal aection whose uppermost part is located on the outside of the joined so that, when the two members are brought together, one of the portions of the blank is collapsed against the peripheral working surface of the first member, and that its other part, located opposite the first member ooté, is folded by the uppermost portion of the section of the second member, and then the entire blank is compressed '\ between the two elements to form a seal .' the L * a thus defined is explained using

drawings that cannot limit the scope.

Figure 1 represents, in section, an example of blank.

Figures 2 and 3 each represents one example of apparatus implementing the method.

The latter two drawings are schematic sectional views, half-cutting line representing the equipment in operation start, while the half-cutting left represents the apparatus upon completion of assembly.

These three figures provide a prefabricated blank section thereof comprises two rectilinear elements forming a right angle therebetween,

Figure 4 in cross-section represents an apparatus implementing a joint whose inner surface is substantially cylindrical. Half-cutting right represents opened tool, while the half-cutting represents the left closed.

On these drawings, the donned marks represent the donned elements.

A particularly important application of the film pile by plastic joints is the can manufacturing and, more particularly, food cans

from sheets of aluminum. This application requires a low cost, thereby assumes machines simple and cheap, working at a high rate, and the provision of joints of a perfect seal.

The method and device that will be herein satisfy this condition.

In a first example of apparatus " starts from a prefabricated blank (10) of a thermoplastic material such as polyethylene, polypropylene, whose cross section comprises two parts (it) and (12) straight and form between them a substantially right angle (fig. 1).

The preform is first heated to a temperature by passing the thermoplastic material of the elastic phase to the plastic phase, while avoiding unacceptable deformation in dimension.

This heating is, preferably, in an air oven widely ventilated, and in a relatively short time, of the order of one minute. In order to ensure the success of this operation, it is important to use a heating medium having a sufficient thermal conductivity, which can be driven at a high speed: air temperature bienbien.la suitable solution depends on the plastic used: it may range from 1° to l40 ^ 0° g for polypropylene.

The blank (10) is taken off at the output of the oven to be implemented, as quickly as possible " around the sheets to be assembled, it is to say, in the case of a box of preserves, on the. box (21) previously filled and provided with its lid (22).

This " driven of the blank is effected by using any known: mechanical, hydraulic, preferably automatically.

The box and its blank are introduced into

a tooling comprising (fig. 2}:

- on the one hand, a first member (31) which has, level with the portion (13) of the blank which rests thereon, a peripheral working surface (311) representing the section it is desired to impart to the corresponding portion of the j-seal

- on the other hand, a second element (32) comprising a concave surface (321) of which the uppermost portion (322) is located on the outside of the seal (10).

When the vessel is moved towards one another the two elements (31) and (32), the top (13) of the seal bears against the working surface (311) of the first member (31) of the tooling, while the portion of the blank which comprises the face (12) is pulled down by the concave portion of the element (32) and being clamped against the underside of the sheets is then accordingly assemblerOn to seal represented by the left side of Figure 2.

The box may be introduced into the first component already provided with its seal; alternatively it can only be introduced therein, and provided with the seal then.

The tooling remains in pressure the time required to move the seal by cooling the plastic phase to the elastic phase, this ensures the preservation integral of its shape, once the assembly is removed from the tooling.

Numerous " embodiments are possible without departing from, however, the present invention 1 · frame.

The working surface of the first member (fold) can have any shape: AI 1 ·οη uses the blank according to Figure 1, it can be given a concave surface in the form of a half-torus (15) conforms to the surface of the blank. It is further not necessary that the surface (511) is identical confectioneries surface (15)

of the blank: i. the surface (511) which, finally, prints its shape to the joint.

It is possible to effect the deformation of the blank into a plurality, pass: the tooling according to Figure 5 it may be made in two passes Y the tool (52) will then have two parts:

- an outer portion (53) whose end (531) is concave portion and whose highest (332) is located outside of the blank (10) ;

- an inner part (54) which slides on the inner side of the outer part (53).

The closure of the blank then determines in two phases the I

- during the first, movement of the member (51) and (53) of the approaching each other causes first the application of the upper face (13) of the seal against the working surface (311), then the folding back of the portion of the blank which comprises the face (12) by the concave portion of the element (33).

- during the second phase, the advantage ** (34) interior slides in the outer portion (33) of the second element of the tooling, applying highly the lower end of 1' blank against the sheets to be joined.

The second member may comprise more than two parts! the inner parts then becomes successively, after movement of the external element (33) and the innermost member.

The element (31) may, in its central region, have any other shape as a planar shape represented *.

It may, for example, be concave so as to allow the containment of a domed lid, or even include a depression to enable construction of two boxes (21) such as laid one on the other * (not shown).

In a second embodiment of the apparatus -

28b, represented by Figure 4, it starts with a blank

(4o) V-prefabricated thermoplastic material, whose face is substantially cylindrical interior *: the angle of the two parts which constitute the section here is substantially equal to an angle ' flat.

The blank includes a side member (4l), for the grasping and holding it in place, and two ears, one greater (42), (43) the other lower.

It is first heated, as it has been explained above, and then placing around the sheets to be assembled, it is to say, in the case of a box of preserves, on the box (51) prefilled and provided with its lid (52).

The box and its blank are then introduced DAA * tooling comprising two tools (61) and (66)

generally cylindrical each of which includes a turnback (62) respectively (67), and a clamping element (63) respectively (68), which elements are movable.

* The two turning members (62) and (6?) move in the direction of arrows (63) and respective (69), so that the element (62) (42) ear flap while the member (67) acts on the ear (43). These two tabs are then clamped between the clamping members (63) and (68), as shown by half-cutting left.

The process and the tools allow assembly of more than two sheets; may be, the K as the d * example, assemble: an outer box of great height, an inner box of lower height and diameter

and a cover, thereby exhibiting, in a single package, two products for sputtering be mixed at the time of use.

The objects and, more particularly, the packages 4

in thin sheets such as the food cans

food, made by the comfortable year using this method and the tooling described feels also described.

i-e