A METHOD FOR AUTOMATICALLY MANUFACTURING GLASS CONTAINERS PROVIDED WITH A STEM, IN PARTICULAR GOBLETS

Abstract: A method for automatically manufacturing glass containers, in particular goblets, provided with a stem, comprises the following phases: blowing or moulding (3) a cup (2); inserting and positioning the cup into a mould (9) provided with a cavity for generating a stem; pressing or injecting (8) into said mould a drop of glass to obtain said stem; stretching said stem in a stretching station (14) and a heat treatment phase (15) consisting of annealing or tempering.

Description: A METHOD FOR AUTOMATICALLY MANUFACTURING GLASS CONTAINERS PROVIDED WITH A STEM, IN PARTICULAR GOBLETS TECHNICAL FIELD AND BACKGROUND ART The present invention relates to a method for automatically manufactuπng glass containers provided with a stem, in particular goblets. The aforesaid method finds particular application in the production of glass goblets, whose aesthetic and hence commercial value is the higher, the better one is able to obtain a thin stem, with no evident signs of closure of the moulds or of junction between the cup and the stem. Methods are known for manufactuπng goblets in which a cup and a disk are produced separately, by means of known techniques such as blowing or pressing. The disk and the cup are joined in proximity to the bottom of the cup, so that the disk serves as a support base for the glass thus obtained. Subsequently, a stretching phase is effected to obtain a stem connecting the cup and the disk. Methods are also known in which to the already formed cup is attached a foot provided with a partially formed stem and which subsequently is heated and stretched to obtained an elongated stem with thin section The known methods described above present some important drawbacks. In the first place, the cup-to-foot attachment phase generates a critical point in which rupture is facilitated and thus makes the goblet particularly delicate in case of impacts or falls. Secondly, the aforesaid methods do not allow to obtain a container, and in particular a goblet with stretched stem, provided with ornaments or decorations in particular in the junction area of the stem to the cup In addition to the aforementioned methods, automatic methods are also known in which the cup, obtained by moulding or blowing, is inserted in a mould that envelops it. This mould has, in addition to the cup housing area, a cavity placed in communication with the cup itself and extending therefrom to generate a stem which may be provided with decorative elements By injecting or pressing a drop of glass into the mould, one automatically obtains a glass provided with a stem which partially envelops the bottom of the cup, possibly with the insertion of decorative effects. Moreover, particular aesthetic effects can be obtained, for instance by producing the cup and the stem in different colours. Furthermore, according to a known automatic method, the cup can comprise a peduncle projecting from the bottom of the cup itself. To obtain a stem, the cup is introduced into an appropriately shaped mould in which a drop of glass is injected or pressed and envelops the peduncle projecting from the cup. Pleasing aesthetic effects can thus be obtained, particularly when the cup and the stem are made in different colours or ha\ e grooves or facets to reflect light differently While the aforesaid methods do allow to obtain a glass that may be enhanced with pleasing aesthetic effects, nonetheless still present some drawbacks. In particular, since the stem is obtained by moulding, it shows the signs of the closure of the mould and it presents a rather large cross section which consequently renders the structure of the goblet heavier. Using the known methods, a product is therefore obtained that has limited aesthetic and commercial value, in consideration of the fact that the aesthetic and commercial value of a glass with a stem, in particular of a goblet, increases as the section of the stem itself diminishes, for equal stem lengths. DISCLOSURE OF INVENTION The aim of the present invention is to eliminate the aforesaid drawbacks making available a method for automatically manufacturing glass containers provided with a stem, in particular goblets, which allows to avoid the formation of junction lines between the cup, stem, and base, whilst guaranteeing the formation of a stem with limited transverse dimensions, without signs of mould closure and possibly embellished with particular ornaments or decorations in proximity to the junction between the cup and the stem Said aims are fully achieved by the method for automatically manufacturing glass containers provided with a stem, in particular goblets, of the present invention, which is characterised by the content of the claims set out below and in particular in that it comprises a phase whereby said stem is stretched, effected in a stretching station BEST MODE FOR CARRYING OUT THE INVENTION This and other features shall become more readily apparent from the following descπption of a preferred form of embodiment illustrated, purely by way of non limiting example, in the accompanying drawing tables, in which' Figure 1 shows a top view of a production plant for carrying out the method of the present invention; Figure 2 shows a cup of a container; Figure 3 shows the cup of Figure 2 in a phase whereby a base is formed, Figures 4 and 5 show the goblet obtained from the phase illustrated in Figure 3 respectively before and after the stem stretching phase; - Figure 6 shows the goblet of Figure 5 in a finishing phase, Figures 7 through 12 show some examples of application of the method of the present invention With reference to the figures, in particular to Figure 1. the reference number 1 globally indicates a plant for the realisation of a method according to the present invention. The phases whereby glass containers provided with a stem, in particular goblets, aie automatically manufactured, preferably take place according to the sequence of work stations shown in Figure 1 This method has the purpose of automatically manufactuπng glass containers, particularly goblets, provided with a stem, and it comprises a first phase whereby a cup 2, shown for instance in Figure 2, is manufactured, by means of any known forming technique Preferably, the cup is obtained by hot pressure blowing of a drop of molten glass into a mould having a cavity with the dimensions of the cup In Figure 1 , the reference number 3 indicates a station for fomnng the cup by means of an automatic pressing, or blowing, or pressure-blowing process Subsequently, the cup 2 is transferred by means of a first transport 4 until reaching a bypass area 5 in which the cup can follow two possible processes. The reference number 6 indicates a cutting station that draw s the cup from the first transport 4 to eliminate the upper residue due to the techniques for forming the cup itself. This cutting phase can be conducted, if necessary, indifferently along the process phases of the glass container and it is schematically shown in Figure 6 in its effects on the final product. From the by-pass area 5 the container can be routed to the cutting station 6, or can continue directly along a second transport 7 to access a pressing station 8. The cup 2, as shown in Figure 3, is inserted into a mould 9 provided w ith a cavity 10 for generating a stem 1 1. This cavity partially envelops the bottom of the cup and extends therefrom, generating both the stem and the support base of the container. A phase then follows whereby a drop of a predefined quantity of molten glass is pressure moulded or injected. In the junction point between the cup and the stem, ornaments or decorations 12 can be provided to enhance the final product Upon completion of the moulding phase, the container provided with a stem, shown for instance in Figure 4, is drawn from the mould and continues along a third transport 13, along which is originally provided a stretching station 14 in which the container with stem undergoes a phase whereby the stem itself is stretched. The stem stretching phase proceeds through a succession of intermediate phases in which the container is loaded into the stretching station and secured at the ends, mechanically or using vacuum. Subsequently, the area to be stretched is heated until reaching the softening temperature of the glass and the actual stretching phase is caπied out controlling the final height and profile. Acting in particular during a stem cooling phase, convex profiles of the stem can be obtained. The container thus obtained, shown for instance in Figure 5, after cooling the stem, is offloaded from the stretching station and continues to a heat treatment station 15 where it is annealed to reduce tensions or tempered, to reinforce the product. Figures 7 and 8, 9 and 10 show two possible container shapes, respectively before and after the stem stretching phase. According to a possible variation, the method of the present invention can comprise the following phases. Firstly, a stem is manufactured and then transfeπed to a blowing station. A cup is then blown, which joins an end of the aforesaid stem. A glass with stem is thereby obtained which can originally undergo a subsequent stretching phase of the stem itself, effected in a stretching station 14, and a heat treatment phase 15, consisting of its annealing or tempering. According to some possible variations, the pressing or injection phase can include the introduction of a drop of glass of the same colour as the cup or of a different colour from the cup Moreover, from the cup forming phase a cup can be obtained that is provided with a peduncle located in correspondence with the bottom of the cup itself, as shown in Figures 1 1 and 12 Subsequently, during the stem manufactuπng phase, the peduncle is destined to be enveloped by the glass drop during the pressing or injecting phase Thus, when the cup and the stem are made in different colours, from the superposition a third colour. en by the combination of the first two, is obtained The method descπbed above can be applied to any method for manufactuπng containers, in particular to known methods for obtaining decorations on the bottom such as drops Moreover the method of the present invention presents considerable advantages, since it allows to obtain for instance a goblet according to an automated method and w ith the possibility of intervening both on the transverse and longitudinal dimensions, and on the profile of the stem Furthermore, the aforesaid method presents ample versatility both in relation to the colour of the cup and/or of the stem, and to the possible presence of decorative elements which may enhance the final product

Claims: CLAIMS 1. A method for automatically manufacturing glass containers, in particular goblets, provided with a stem, of the type comprising the following phases, blowing or moulding (3) a cup (2); inserting and positioning the cup into a mould (9) w hich defines a cavity ( 10) for generating a stem (1 1); pressing or injecting (8) into said mould a glass drop to obtain said stem (1 1); characterised in that it compπses a phases whereby said stem ( 1 1 ) is stretched, effected in a stretching station (14). and a heat treatment phase ( 15) consisting of annealing or tempering. 2. A method for automatically manufacturing glass containers, in particular goblets, provided with a stem, of the type comprising the following phases: manufacturing a stem; transferring said stem to a blowing station; blowing a cup (2) on said stem; characteπsed in that it compπses a phase whereby said stem ( 1 1 ) is stretched, effected in a stretching station (14), and a heat treatment phase (15) consisting of annealing or tempering. 3. A method as claimed in any of the previous claims, wherein said stem stretching phase comprises the following phases: - loading the container into the stretching station (14); blocking at least an end of the container; heating the area of the stem (1 1) to its softening temperature, stretching the stem while controlling its profile and height; cooling the area of the stem ( 1 1 ) to prevent subsequent deformations; off-loading the container from the stretching station ( 14). 4. A method as claimed in claim 1 , wherein said pressing or injecting phase compπses the introduction of a drop of glass of the same colour as the cup. 5. A method as claimed in claim 1 , wherein said pressing or injecting phase compπses the introduction of a drop of glass of a different colour from the cup 6. A method as claimed in claim 1, wherein said phase of blowing or moulding a cup compnses the forming of a peduncle positioned in coπespondence with the bottom of the cup itself, said peduncle being destined to be enveloped by the glass drop which forms said stem during the pressing or injection phase.

Inventors: DI GIUSEPPANTINO VINCENZO, PALOSCHI FABIO, DI GIUSEPPANTINO, VINCENZO, PALOSCHI, FABIO
Applicants: BORMIOLI ROCCO & FIGLIO SPA, GIUSEPPANTINO VINCENZO DI, PALOSCHI FABIO, BORMIOLI ROCCO & FIGLIO S.P.A., DI GIUSEPPANTINO, VINCENZO, PALOSCHI, FABIO
Application year: 2000
Main classification: C03B9
IPC codes: C03B9