DESCRIPTION

"Coffee maker and manufacturing method"

[0001] . Object of the present invention is a device for the preparation of hot drinks, in particular for the preparation of infusions obtained from coffee or barley powder or the like.

[0002] . Also object of the present invention is the method for the manufacturing of such device. [0003] . Here and below, with the term "coffee maker" it is intended any one device for the preparation of hot drinks, in particular for the preparation of coffee, cappuccino, coffee with milk or other infusions obtained from coffee or barley powder or the like. [0004] . In the manufacturing of the coffee maker, the use of aluminium and its alloys is particularly appreciated.

[0005] . Such alloys, in fact, along with optimal behaviour from the standpoint of the drink preparation, permit a relative easy casting and working of the machine tool during the production of the coffee maker components.

[0006] . The technologies which can be used in such production are the chill casting, pressure die-casting, lost wax or investment casting, sand mold casting, drawing, hot extrusion and cold extrusion.

[0007] . The most appreciated technologies however are the chill casting and the pressure die-casting. Such technologies permit an optimal production quality and relatively low working times and costs. In particular, such technologies permit, with respect to the others, an improved control of the thicknesses and volumes and an improved surface finishing in connection with a greater possibility for automation and manpower reduction.

[0008] . Such production technologies, however, while appreciated and widely used, are not free of defects.

[0009] . Both the pressure die-casting and the chill casting, for example, require the removal of the core from the inside of the pieces wherein it is desired to obtain cavities. The need to remove the casting core sets strong limitations on the ratios between the size of the cavity opening and the undercut which can be obtained in the final piece.

[0010] . The strong technical limitations translate into the same number of limitations from the design standpoint of the coffee makers obtained by means of conventional chill casting and/or pressure die-casting technologies.

[0011] . Such limitations can be partially overcome by means of the cleaning of the casting pieces at the machine tool. This solution/ however, requires a clear increase of production times and costs.

[0012] . Object of the present invention is that of devising and making available a coffee maker and a method for the manufacturing of such coffee maker which permits at least partially overcoming the drawbacks lamented above with reference to the prior art .

[0013] . In particular, task of the present invention is to make available a manufacturing method of coffee makers which does not set strong technological limitations on the design. [0014] . Also task of the present invention is to make a coffee maker available whose design does not have strong technological limitations .

[0015] . Such object and such tasks are achieved by means of a coffee maker in accordance with claim 1 and by means of a coffee maker manufacturing method in accordance with claim 11.

[0016] . Further characteristics and advantages of the coffee maker and method will be clear from the following description of preferred embodiments, with reference to the enclosed figures wherein:

[0017] . Figure 1 schematically illustrates a coffee maker of known type;

[0018] . Figure 2 schematically illustrates in section the collector of a coffee maker of known type; [0019] . Figure 3 schematically illustrates in section

the boiler of a coffee maker of known type;

[0020] . Figure 4 schematically illustrates in section a first boiler embodiment of a coffee maker according to the invention; [0021] . Figure 5 schematically illustrates the boiler of figure 4 in section, during a production step;

[0022] . Figure 6 schematically illustrates in section a second boiler embodiment of a coffee maker according to the invention; [0023] . Figure 7 schematically illustrates in section a third boiler embodiment of a coffee maker according to the invention;

[0024] . Figure 8 schematically illustrates in section a fourth boiler embodiment of a coffee maker according to the invention;

[0025] . Figure 9 schematically illustrates in section a first collector embodiment of a coffee maker according to the invention;

[0026] . Figure 10 schematically illustrates in section the collector of figure 9, during a production step;

[0027] . Figure 11 schematically illustrates in section a second embodiment of a collector of a coffee maker according to the invention;

[0028] . Figure 12 schematically illustrates in section the collector of figure 11 during a production step;

[0029] . Figures 13 - 16 schematically represent several steps of the production process in detail according to the invention.

[0030] . Below, the meanings of the expressions "upper" and "lower" or "high" and "low" or "above" and "below" or the like are referred to the coffee maker in its normal support orientation. The normal support position is that which permits stably placing the coffee maker on a stove in order to prepare the coffee drink, or that wherein the upper container is capable of containing the maximum amount of drink without leaks\.

[0031] . With particular reference to figure 1, a coffee maker is indicated in its entirety with 1. The coffee maker 1 comprises, in a known manner, a collector 2 and a boiler 3.

[0032] . The coffee maker 1, in order to function correctly and in a safe and comfortable manner for the user, must also comprise other elements. Several are visible in figure 1: a cover 40 with a knob 41, a handle 42 and a safety valve 43. Others are not represented: a funnel, a filter and a gasket. Such elements are however irrelevant with regard to the present invention and thus will not be considered below. [0033] . The collector 2 comprises side walls 20, a bottom 21 on which a column 22 is inserted and coupling

means 23.

[0034] . The boiler 3 comprises a jacket 30, a base 31 and coupling means 32 complementary to the coupling means 23 of the collector 2. [0035] . Preferably, the coupling means comprise a threaded band 23 on the collector 2 and a complementary threaded band 32 on the boiler 3.

[0036] . Alternatively, the coupling means 23 and 32 can comprise a bayonet joint, a lever constraint or the like. [0037] . Conventionally, the boiler 3 comprises a cavity 35 wherein the lower base 33, constituted by the upper surface of the base 31, has greater inner dimensions than the opening 34. With reference to the figure 3, it is noted how the characteristic dimension (or diameter) d of the opening 34 is less than the characteristic dimension (or diameter) D of the base 33.

[0038] . This form is particularly appreciated since it permits obtaining good efficiency in the heat exchange with the stove and at the same time ensures the stability of the support.

[0039] . The above described boiler 3 can be obtained by pressure die-casting, lost wax casting, sand casting, drawing, hot extrusion, cold extrusion or, preferably, by chill casting. In any case, given the undercut, the cavity 35 is conventionally originated from a

disasseiϊiblable core, i.e. obtained in several inserts which can be extracted one at a time through the opening 34, permitting the obtainment of the wide undercut visible in figure 3. [0040] . In the industrial use of this production, two needs are demonstrated. On the one hand there is the need to easily extract the pieces through the opening 34; on the other hand there is the need to limit the complexity of the disassemblable core and therefore limit the number of inserts which form it . From this there derives the practical impossibility of arbitrarily reducing the dimensions of the single inserts.

[0041] . These needs in fact impose a ratio between the dimension d of the opening 34 and the dimension D of the base 33 of the boiler 3. Such ratio is schematically shown in the section of figure 3. In particular, for coffee makers of known type, the ratio d/D is normally greater than 0.6 and exceptionally can decrease to a limit of 0.5. [0042] . The coffee maker l in accordance with the present invention comprises a boiler 3 and a collector 2 wherein at least the collector 2 or the boiler 3 comprises at least two components produced separately in pure or nearly pure aluminium or in aluminium alloy and subsequently welded together by flash welding.

[0043] . With reference for example to figures 4 and 5, the boiler 3 according to the invention comprises a jacket 30 and a base 31. Such separately produced components are then joined together by means of flash welding, fitting them along the direction of the arrow A of figure 5.

[0044] . Due to the fact that the jacket 30 and the base v 31 are separately produced, they can be indiscriminately obtained by means of one of the abovementioned technologies, preferably by means of chill casting or pressure die-casting, without encountering any complication related to the disassemblable core. The components, in fact, as can be seen in figure 5, do not have any undercut. [0045]. As can be noted in figure 4, the d/D ratio of the boiler 3 according to the invention can be clearly lower with respect to the technological limit of 0.5 which was mentioned above w^Lth reference to the prior art. The embodiment of figure 4 has a d/D ratio equal to about 0.43.

[0046] . The joining of the jacket 30 to the base 31 , separately produced, occurs by means of flash welding . A preferred method of flash welding is described in detail below. [0047] . Figures 6 and 7 represent other possible

embodiments of the boiler 3 according to the invention. In accordance with such .embodiments, the base 31 comprises an edge 311 which extends towards the jacket 30. In such embodiments, the joint line 310 is shown along which the flash welding occurred.

[0048] . The embodiment of figure 6 shows, by means of different section lining, how the base 31 and the related edge 311 are produced with a different aluminium alloy with respect to that with which the jacket 30 is produced.

[0049] . The two components of the boiler 3 of figure 6 can for example be produced by different technologies and consequently with different aVLuminium alloys. [0050] . An alloy typically employed for the pressure die-casting is in fact the alloy known from the related

UNI regulation of 1974: UNI 5076 (later UNI-EN 46100).

This alloy has a theoretical composition of 12% silicon,

2% copper, 0.9% iron and aluminium to complete it.

[0051] . An alloy typically employed for the chill casting is instead the alloy known from the related UNI regulation of 1950 as SG-AL-CU 1°. This alloy has a theoretical composition of 1.6% silicon, 5.5% copper and aluminium to complete it. [0052] . The difference between the two employed alloys does not affect the possibility of joining the related

components by means of flash welding.

[0053] . On the other hand, the possibility to produce each component with the technology most adapted for the specific case leads to clear advantages with regard to the production optimisation.

[0054] . Figures 6 and 7 schematically represent different boiler forms according to the invention. Such forms, due to the particular conformation of the cavity 35, cannot be obtained by means of the conventional technologies, in particular by means of chill casting with disassemblable core.

[0055] . Figure 8 represents a further embodiment of the boiler 3 according to the invention. It comprises, in addition to the jacket 30 and the base 31, an additional plate 312 in ferromagnetic material, for example stainless steel.

[0056] . The boiler of figure 8, like that of figure 6, is also obtained with different technologies and alloys. In accordance with this specific case, the jacket 30 can be obtained by means of chill casting, pressure die- casting, drawing, cold and hot extrusion, lost wax casting or sand casting, while the base 31 is obtained by means of pressure die-casting. The jacket 30 and the base 31 are joined by means of flash welding. The plate 312 can be joined to the base 31 by means of braze welding,

impact bonding, or laser welding.

[0057] . The boiler of figure 8, while having a traditional d/D ratio and thus having an overall form similar to the known coffee makers, cannot be manufactured by means of the traditional technologies. In fact, the coupling of the plate 312 to the base 31 cannot occur with the normally used aluminium alloys . [0058] . In order to obtain a reliable coupling, whether this is obtained by braze welding, impact bonding, or laser welding, it is necessary that the base 31 is produced in pure or nearly pure aluminium, i.e. with purity greater than 99.5%.

[0059] . The presence of the plate 312 in ferromagnetic material permits the use of *a coffee maker 1 comprising the boiler 3 of figure 8 also on induction plates, on which the common aluminium alloy coffee makers do not function.

[0060] . All that said above for the boiler 3 can be extended with regard to the collector 2. [0061] . Conventionally, the collector 2 comprises a cavity wherein the lower base, composed of the upper surface of the bottom 21, has lesser inner dimensions at the opening. With reference to figure 2, it is clearly noted that the characteristic dimension (or diameter) of the opening is less than the characteristic dimension (or

diameter) of the base.

[0062] . Such form is particularly appreciated because it facilitates the cleaning operations. In the aluminium alloy coffee makers, the collector 2 described above is obtained in a simple manner by means of the conventional technologies . The piece does not in fact have any undercut .

[0063] . With reference for example to figures 9 and 10, the collector 2 according invention comprises side walls 20 and a bottom 21 from which the column 22 rises. Such components, produced separately, are then joined by means of flash welding, fitting them along the direction of the arrow A of figure 10. [0064] . Due to the fact that the side walls 20 and the bottom 21 are separately produced, they can be indiscriminately obtained by means of the most adapted technologies, preferably by means of chill casting or pressure die-casting. It is thus possible to choose for each component the technology most adapted for the specific case. In fact, the single components, as can be seen in figure 10, do not have any undercut. [0065] . As may be noted in figure 9, however, the collector 2 according to the invention can have a clear overall undercut. [0066] . This form cannot be obtained with the

conventional technologies with disasseiriblable core (like chill casting, for example) , without unacceptable complications. The presence of the column 22 at the centre of the collector 2 in\fact further complicates the movement and removal of the possible inserts.

[0067]. With reference to figures 11 and 12, the collector 2 according to the invention comprises side walls 20 and a bottom 21, separately produced. In the specific case, as can be seen in figure 12, the side walls 20 are in turn constituted by at least two half- shells 20' and 20" .

[0068]. The half-shells 20' and 20", separately produced, are joined by means of flash welding, fitting them along the direction of the arrow A of figure 12. Subsequently, the side walls* 20 and the bottom 21 are in turn joined by means of flash welding, fitting them along the direction of the arrow B of figure 12. [0069] . Due to the fact that the half-shells 20' and 20" and the bottom 21 are separately produced, they can be indiscriminately obtained by means of chill casting, pressure die-casting, drawing, cold or hot extrusion, lost wax casting or sand casting, choosing for each component the technology most adapted to the specific case. The single components, in fact, as can be seen in figure 12, do not have any undercut.

[0070] . As can be seen in figure 11, however, not only the collector 2 but also the side walls 20 can have a clear undercut in their entirety.

[0071] . With reference to figures 13 - 16, the flash welding process is described below, preferably used in the manufacturing of the boiler 3 and/or collector 2 according to the invention.

[0072] . Figure 13 schematically represents two generic components 101 and 102 which must be welded in the direction of the arrow A. The two components are placed in the reciprocal position in which, except for the approaching in the direction A, they will be found when they are welded. Each of the two components comprises a disposable stock metal 103 of thickness t shown with a dashed line in figure 13.

[0073] . Figure 14 represents the two components 101 and 102 to which an adequate potential difference V is applied. In addition, the components are set at a distance which permits the formation of sparks and hence a passage of electric current between the two components.

The current passage heats, by Joule effect, the zones of the components affected by the spark until they are melted.

[0074] . Figure 15 represents the two components 101 and 102 which are pressed against each other by opposed

forces F. The zones of the components which are found in the melted state come into contact with each other, penetrating each other. The disposable stock metal 103 is deformed, forming a burr 104 along the entire joint. [0075] . Figure 16 represents the finished piece 100, after the burr 104 has been removed, for example by- working with the machine tool. At the end of the described process, the hydraulic, aesthetic and mechanical characteristics of the welded piece 100 are substantially the same of an analogous single piece.

[0076] . The man skilled in the art will appreciate from that described above how the flash welding is an autogenous welding, i.e. it does not require the aid of any weld metal. This characteristic of the welding process is extremely advantageous in the case of containers like the boiler i and the collector 2, which are intended to come into contact with drinks. [0077] . The coffee maker according to the invention therefore ensures the hydraulic seal both for the leakage of liquids as well as gases and vapours.

[0078] . Moreover, the coffee maker according to the invention ensures an aesthetic finishing of absolutely comparable quality to that of traditional coffee makers. In particular, the joint line obtained with the flash welding, once cleaned, is substantially invisible.

[0079] . Above all, however, the coffee maker according to the invention has a mechanical strength equal to that of a conventional coffee maker.

[0080] . Such characteristic is particularly important for the boiler 3 which, during functioning, is subjected to internal pressure cycles. Specific tests conducted by the applicant have shown that the mechanical strength at the internal pressure of a boiler according to the invention is equal to that of conventional single piece boilers.

[0081] . It will be clear tt> the man skilled in the art from that described above how the coffee maker according to the invention resolves the problems underlined in relation to the coffee makers known type while maintaining the same safety standards.

[0082] . In particular, from that described above, it will be clear to the man skilled in the art how the coffee maker according to the invention is not affected by the technical limitations which afflict the design of the coffee makers of known type.

[0083] . A man skilled in the art, with regard to the embodiments of the coffee maker and manufacturing method described above and in order to satisfy continent needs, can make modifications, adaptations and substitutions of elements with other functionally equivalent elements,

without departing from the scope of the following claims. Each of the described characteristics belonging to a possible embodiment can be manufactured independently from the other described embodiments.

*** ***