EP1214994B1

EP1214994B1 - A process for the realization of at least an impression on the surface of a metal container

Info

Publication number: EP1214994B1
Application number: EP01129572A
Authority: EP
Inventors: Roberto Frattini
Original assignee: FRATTINI COSTR MECC; Frattini Spa-Costruzioni Meccaniche
Current assignee: Mall and Herlan Schweiz AG
Priority date: 2000-12-18
Filing date: 2001-12-12
Publication date: 2006-08-02
Anticipated expiration: 2021-12-12
Also published as: ES2267658T3; ATE334765T1; EP1214994A1; ITMI20002732A1; DE60121905T2; IT1319568B1; DE60121905D1

Abstract

A process for the realization of impressions (16-16') on metal containers (10), in particular a container of the type of cylindrical enbloc atomizing bomb obtained by means of operating steps of tapering, customized cutting, upper edging and control from an extruded, drawn or deep-drawn body (10) painted in the inside and the outside, and lithographed, said operations being sequentially carried out on a multiple station rotary table tapering machine. The process includes the steps of: providing the external surface of said body (10), before submitting it to the aforesaid operations, with at least one signal (14) obtained in an angular prefixed position with respect to the zone selected for the impression (16,16'); feeding said body (10) on the tapering machine; positioning said body (10) in such a manner that the zone prefixed for the impression be aligned with a device to obtain the impression; locking said body in the fixed position, and making at least one impression (16,16') on at least said prefixed zone of body (10) through said device. <IMAGE>

Description

The present invention relates to a process for the realization of at least an impression on the surface of a metal containers, according to the preamble of claim 1.
More particularly, the present invention relates to a process for the realization of at least one raised or recessed impression along a well determined and prefixed zone of the lateral surface of a metal container.
The containers employed in the process of the present invention are especially those made from aluminum, alloys thereof, steel or like metal containers intended for the formation of enbloc aerosol bombs or container having a substantially cylindrical form, with a tapered upper end and provided at the mouth with a collar for the subsequent application of a delivery valve.
Said containers are obtained from extruded, drawn or deep-drawn bodies or preforms, which, before being submitted to tapering, are painted both in the inside and on the outside, and lithographed on the lateral surface to create thereon writings or decorative elements, such as for instance the mark of the product.
The extruded, drawn or deep-drawn, painted or lithographed containers are then fed to a so-called tapering machine that perform on the same several sequential operations among which the shaping of the bottom, the progressive tapering of the upper part adjoining the mouth and the mouth edge, to form the engagement or stabilization seat for a delivery valve.
Tapering machines of this type are already known in the literature. So, for instance, patent EP-A-0275369 discloses a rotary-table multi-station tapering machine comprising an intermittent rotating table, provided with pliers or grasping means intended for the fastening of the extruded or drawn, painted and lithographed body, and an opposite front drum having an alternated translation motion and bearing a plurality of forming tools or spindles, that operate sequentially on said extruded or drawn body, carrying out the operations of tapering, customized cutting, forming the upper edge and the control.
Among the different operations carried out on the cylindrical preform, there is comprised that of the formation of an annular groove, near to the tapered portion, for the application and the stabilization of a lid on the finished containers.
The containers obtained according to the known art have an entirely smooth lateral surface, both on the cylindrically developed part and the upper tapered zone: the lithography made in the inside of the containers does not determine, in fact, raised or recessed sectors recognizable by touch.
The present requirement is, vice-versa, oriented at realizing on the containers of the type in question, and in particular on predetermined zones of their lateral surface, protrudied or recessed impressions having various configurations and size.
Said impressions have ESSENTIALLY an aesthetic and decorative function, but if they are obtained with special configurations, for instance with the form of horizontal, rectilinear and superposed protruding and recessing grooves, they have also a functional action. They, in fact, interrupt the smooth development of the lateral surface of the container and create a surface roughing that facilitate the grasp and handling of the containers by the final user.
US-A-3 628 451 discloses a process for the realisation of impressions on metal containers wherein the containers are provided in correspondence of the mouth with at least a signal, aligned and arranged according to an angle position pre-defined with respect to the container zone along which the impressions must be obtained, said containers being rotary located and subsequently locked at a pre-defined angle with respect this signal and embossed in one or more points of its sidewall by means of a device suitable to realise said impressions.
The formation of such impressions along the lateral surface of the containers involves several problems, the first of which concerns the precise positioning of the containers in the mold or matrix.
As specified above, said containers are submitted to the operation of realization of said raised and/or recessed impressions, when they have already the form of a finished extruded or drawn piece, i.e. painted both in the inside and especially outside, with a lithographed surface and, therefore, provided with writings and decorations along well determined zones. The realization of the impressions, for instance raised or recessed impressions parallel and superposed to each other, must take place on the free zones, so as not to alter or superpose to the pre-existing writings and decorations. In fact, the writings and decorations are advantageously obtained in such a way as to leave along the lateral surface at least one free zone, provided with painting, but free from other visual or decorative elements. It is therefore necessary that said free zone(s) be identified with the utmost precision.
Another drawback is the device used to make such raised or recessed impressions. Generally, in fact, such impressions are obtained with different devices separate from the tapering machine employed for the production of containers, starting from an extruded or drawn and deep-drawn body. This unavoidably involves higher production costs and a reduction in the amount of pieces obtained.
Object of the present invention is to solve the aforementioned drawbacks.
More particularly, object of the present invention is to provide a process allowing to realize raised and/or recessed impressions in a predetermined and localized zone of an extruded or drawn, deep-drawn, painted and lithographed body.
Another objet of the present invention is to provide a process allowing to produce raised and/or recessed impressions in a prefixed and localized zone of an extruded or drawn, deep-drawn, painted and lithographed body by using the same tapering machine that performs the other working steps to realize said tapered and edged containers.
According to the present invention, these and other objects that will become apparent from the following description are obtained by means of a process for the realization of at least one impression on the surface of a metal container, in particular a container of the enbloc atomizing cylindrical type having a tapered and edged upper end and an opposite lower end provided with a bottom, painted both in the inside and the outside and lithographed on the external lateral surface; said metal container being obtained by subjecting an extruded, drawn or deep-drawn body to the following operating steps:

painting both in the inside and the outside,
lithographing the external lateral surface,
tapering the painted and lithographed container,
customised cutting the tapered container, and
upper edging and control the cut and tapered container,

providing the external surface of the container with at least a signal obtained in an angular position prefixed with respect to the zone selected for the impression;
positioning the container in such a manner that the zone prefixed for the impression be aligned with a device producing the impression;
locking the container in the prefixed position, and
making at least one impression on at least said prefixed zone of the container by means of said device producing the impression; characterized in that, in order to successively carry out all said operating steps of tapering, cutting, edging and realisation of at least one impression with the same multi-station, rotary table tapering machine, the following process conditions are used:
- a) the operating step of realisation of at least one impression is carried out on the extruded, drawn or deep-drawn painted and lithographed body before the tapering operating step;
- b) the signal is provided on the upper edge of the body during or immediately after the painting or the lithographing step, and
- c) the body during the operating steps is housed and locked, in correspondence of its bottom, in a pliers connected to a control orienting device comprising a detector of the signal.

The main features of the process of the present invention concern the following operating steps: each extruded or drawn and deep-drawn body is provided, during the painting or the lithography process or immediately afterwards, with at least one notch or reference signal along the edge or mouth zone, and it is subsequently locked in the matrix of the tapering machine that makes the impressions in correspondence of said at least one notch or reference signal, detected by optical means associated to said matrix.
The detection optical means, which may be a photocell, a video-camera or laser rays, acts on the central control unit of the tapering machine, in order to position and lock the extruded or drawn body.
Once the impressions on the lateral surface of the container have been obtained in the prefixed zone in alignment with the notch or signal, said container is submitted, on the same tapering machine, to the subsequent and known operating steps of tapering, cutting, formation of the mouth collar, and control.
Preferably, the impressions are obtained by rolling on a zone or along two or more zones of the lateral surface of the body , with the same matrix, or alternatively with two adjoining matrices located on the rotating table of the tapering machine.
The impressions may also be obtained on two diametrically opposed zones.
The process of the present invention will be better understood thanks to the following description, wherein reference is made to the figures of the herewith enclosed drawings that illustrate in a schematic view a container provided with impressions obtained by means of said process, and wherein:

Figure 1 shows the front schematic view of the container provided with impressions carried out according to the process of the present invention, before the tapering operations;
Figure 2 shows a lateral schematic view of the same container of Figure 1, to stress the conformation of the impressions according to a preferred embodiment;
Figure 2A shows the lateral schematic view of an enlarged detail of Figure 2, to stress said impressions;
Figure 3 shows a perspective schematic view of a container according to an alternative embodiment of the impressions made with the process of the present invention, before the tapering operations;
Figure 4 shows the lateral schematic view of the same container of Figure 3; and
Figure 4A shows the lateral schematic view of an enlarged detail of figure 4, to stress the impressions obtained according to said alternative embodiment.

With reference to the figures, the cylindrical body or preform, indicated by 10 as a whole, is preferably obtained from aluminum or alloys thereof by means of extrusion or deep-drawing and drawing operations, known per se. Said body or preform 10 comprises at an end an upper strip 12, corresponding to the edge, and, at the opposite end, a bottom.
The body or preform 10 is painted both in the inside and in the outside, and lithographed along the external lateral surface, to create thereon writings and/or decorations. During the steps of painting and lithographing, or immediately after, along the upper strip 12, at least one notch or reference signal 14 is produced. This notch or reference signal 14 is aligned or arranged according to a pre-defined angle position with respect to the zone of the external lateral surface whereon the raised or recessed impressions are to be obtained, and which is free from writings and/or decorations,
The body or preform 10 is therefore housed in a pliers or grasping means connected to a numeric control orienting device of the tapering machine that comprises a detector of the notch or reference signal 14.
Said detector is preferably of the optic type and may be, for instance, a photocell, a video camera or a laser ray device connected with the central control unit of said numeric control orienting device.
The detector is fixed and identifies the notch or signal 14, while the container 10 is caused to rotated on the grasping means or pliers associated to the numeric control orienting device, in a position adjoining it. Once notch or signal 14 is identified, the rotation is stopped, and the container 10 is pre-locked in correspondence of its bottom, i.e. in a position opposite to the edge whereon notch or signal 14 has been produced. Such rotation stop is activated by the orienting device and takes place, with reference to signal 14, in a pre-determined position depending on the parameters set in the numeric control device.
The subsequent process step consists in the stable locking of container 10, with known means, and in the formation of the impressions which, in an exemplary embodiment shown in Figures 1 and 2, are constituted by superposed recessed grooves 16 having a tendentially semicircular profile, and an extension, by way of example, equal to about one third the circumference of container 10. Said impressions are obtained by means of a rolling straining device at one of the operating stations of the tapering machine, or by means of a static device with a molding operation. With the same rolling straining device impressions 16 on one only zone of the container 10 or along two or more zones of said container may be obtained.
As an alternative, two different rolling straining devices or static devices may be utilized in the same tapering machine, to realize impressions 16 along said zones.
The impressions can be also obtained along diametrically opposed zones.
Figures 3 and 4 show by way of example a container 10 whereon raised instead of recessed impressions 16' are obtained.
Before the step of optical detection of the notch or signal 14 and the subsequent realization of impressions 16, 16', the container 10, painted and lithographed, is advantageously submitted, with an intervention known per se, to the molding of the bottom, which is convex towards the inside of the body.
Once impressions 16, 16' have been produced, the operating cycle continues on the same tapering machine with further and conventional steps of tapering, customized cutting, upper edge and control for the formation of a cylindrical container, with a tapered and edged upper end. Said steps are optionally preceded by an annular cut operation of the upper part of said container 10, in order to align the mouth that may undergo a misalignment due to the strains arising from the creation of impressions 16, 16'.
The notch or signal 14 obtained along the mouth is advantageously realized with paint or ink of a color contrasting with that used for the external painting of container 10, or in any case, in contrast with the edge zone.
While the present invention has been described above with reference to a specific process, various changes and modifications may be introduced in the light of the above description within the scope of the following claims

Claims

A process for the realisation of at least one impression (16, 16') on the surface of a metal container, in particular a container of cylindrical enbloc atomised bomb type having a tapered and edged upper end (12) and an opposite lower end provided with a bottom, painted both in the inside and the outside and lithographed on the external lateral surface; said metal container being obtained by subjecting an extruded, drawn or deep-drawn body (10) to the following operating steps:
- painting both in the inside and the outside,

- lithographing the external lateral surface,

- tapering the painted and lithographed container,

- customised cutting the tapered container, and

- upper edging and control the cut and tapered container,
said operating steps of tapering, cutting and edging being carried out successively with a multi-station, rotary table tapering machine;
said process for the realisation of at least one impression comprises:
- providing the external surface of the container with at least a signal (14) obtained in an angular position prefixed with respect to the zone selected for the impression (16, 16');

- positioning the container in such a manner that the zone prefixed for the impression be aligned with a device producing the impression;

- locking the container in the prefixed position, and

- making at least one impression (16, 16') on at least said prefixed zone of the container by means of said device producing the impression;
characterised in that, in order to successively carry out all said operating steps of tapering, cutting, edging and realisation of at least one impression with the same multi-station, rotary table tapering machine, the following process conditions are used:
a) the operating step of realisation of at least one impression is carried out on the extruded, drawn or deep-drawn painted and lithographed body (10) before the tapering operating step;

b) the signal (14) is provided on the upper edge (12) of the body (10) during or immediately after the painting or the lithographing step, and

c) the body (10) during the operating steps is housed and locked, in correspondence of its bottom, in a pliers connected to a control orienting device comprising a detector of the signal (14).
The process according to claim 1, characterised in that the painted and lithographed body (10), before the positioning and the realisation of at least one impression, is submitted to the moulding of the bottom to make it convex towards the inside of the body.
The process according to claim 1 or 2, characterized in that the at least one signal (14) is detected by an optical device connected to a numeric control orienting device of the tapering machine, that positions and locks the extruded or drawn body.
The process according to claim 1 or 2, characterized in that the at least one signal (14) consists of at least one impression obtained by means of painting or lithography with a paint in color-contrast with that used for the external painting or with the edge zone.
The process according to any of the preceding claims, characterized in that the at least one impression (16, 16') is raised and/or recessed.
The process according to claim 5, characterized in that said at least one impression (16, 16') is obtained by rolling straining or with a static molding tool.
The process according to any one of the preceding claims , characterized in that said at least the impression (16, 16') is obtained along one or more zones of the lateral surface of the extruded or drawn body (10).
The process according to claim 3, characterized in that said optical device for the detection of the signal (14) is a photocell.
The process according to claim 3, characterized in that said optical device for the detection of the signal (14) is a video-camera.
The process according to claim 3, characterized in that said optical device for the detection of the signal (14) is of a laser ray device.