Hemming and seaming machine equipped with rotating head

Abstract

A hemming and seaming machine (9), for hemming and seaming a lid (1) to a container (2), comprises a supporting frame (10), which includes: an upright (12), extended along a primary axis (x) and a structure (14) supported by the upright (12) in a rotatable manner around such primary axis (x); at least a pair of mandrels (16), carried by the structure (14) and rotatable around respective secondary axes (y), parallel to the primary axis (x); at least two pairs of rollers (18a, 18b, 19a, 19b), carried by the structure (14), each of the at least two pairs of rollers being associated with a respective mandrel (16); and a single plate (26), coaxial to one of the mandrels (16) and adapted to form a rotatable support for the base of a container axially interposable between such plate (26) and the respective mandrel (16), so that, for each hemming and seaming cycle, there is only one pair of rollers (18a, 18b, 19a, 19b), among all the rollers (18a, 18b, 19a, 19b) included in the hemming and seaming machine (9), which engages the radially outer edges of the lid (1) and the container (2).

Description

Technical field

[0001] The present invention is placed, in general, in the sector of the equipment for bottling food liquids; in particular, the invention refers to a hemming and seaming machine, for the application of lids to cylindrical metal containers containing a food beverage.Technical note

[0002] Hemming and seaming machines adapted to apply lids to metal containers are known.

[0003] Such machines comprise a plurality of rotatable mandrels, coaxial to respective rotating plates, so that the containers, on which to apply the respective lids, are interposed between the two.

[0004] The mandrels have edges adapted to guide, during the hemming and seaming, the deformation of the outer edges of the respective lid and container, each mandrel cooperating with a pair of rollers having different circumferential profiles, so that, alternatively approaching the two rollers to the mandrel in radial direction, the outer edges of the lid and of the container, constricted between the roller and the mandrel, undergo a plastic deformation in two steps.

[0005] In a first step of the hemming and seaming cycle, as for example illustrated in the sequence of images shown in Figure 1A, the outer edges of the lid and of the container are superimposed and turned downwards outside the container (effectively being curled so that the part of the outer edge of the lid is underneath the outer edge of the container).

[0006] In a second step of the hemming and seaming cycle, the edges curled in such manner of the lid and of the container are radially squashed, so as to become at least in part parallel to the outer wall of the container (as for example illustrated in the sequence of images shown in Figure 1B).

[0007] Typically, a hemming and seaming machine comprises a plurality of mandrels and plates all carried by a ring carousel for moving along a circular hemming and seaming path; a pair of rollers carried by the carousel as well being associated with each mandrel.

[0008] Such a configuration lends itself very well for mass production, since it offers the possibility of simultaneously working a plurality of containers, thus ensuring a high production volume.

[0009] However, such a machine is costly (as regards both purchase and maintenance) and functionally very rigid, therefore it is not suitable for small lot productions (for example, in the case of artisan producers), especially when it is necessary to change size, i.e. when the machine has to operate on containers and lids different from one another as to geometry and / or dimensions. In fact, changing size on a machine of this type entails the disassembling thereof and / or the replacement of all or part of the rollers and / or the change of all the mandrels, with a great waste of time and high intervention costs, since it requires the presence of personnel technically qualified to dismantle and reconfigure the machine, the latter operations being particularly complex, especially because they require the repositioning of the rollers with respect to the mandrels which has to be carried out respecting tolerances in the order of a few hundredths of a millimeter, tolerances difficult to obtain by a medium-small sized producer that generally does not have a sufficient preparation for obtaining a similar level of precision, unlike the producer of the same machine.

[0010] Such limitations, understandably, prejudice the possibility of using a hemming and seaming machine of a known type in the productions of small series and thus with frequent production changes. The above hemming and seaming machines are disclosed in WO 2019 / 004947 A1, which is considered to form the basis for the preamble of claim 1, in US 2 467 154 A and in US 2 737 137 A.Summary of the invention

[0011] An object of the present invention is to overcome the abovementioned problems.

[0012] In order to obtain such result, a hemming and seaming machine according to the present invention comprises a supporting frame, equipped with at least two hemming and seaming heads each one having a forming mandrel and a pair of rollers each one cooperating with the relative mandrel.

[0013] A single work station is also present comprising a single rotating plate adapted to form a base rotatable around a fixed axis for a container on which to apply a lid. The machine is configured to carry the mandrel of only one of the two hemming and seaming heads in a position coaxial to such rotating plate, so that the hemming and seaming machine can assemble a lid to only one container at a time. In other words, the hemming and seaming machine is configured so that, while a single mandrel cooperates with the rotating plate in the hemming and seaming of a lid to a container, the other mandrels of the other hemming and seaming heads do not operate on any container, no further rotating plates being associated with such mandrels in the hemming and seaming station. The exchange of the hemming and seaming heads inside the hemming and seaming station allows carrying a different mandrel and / or different rollers or the same rollers arranged in different positions with respect to the mandrel at the rotating plate, so as to be able to operate with a different mandrel / rollers assembly.

[0014] The two hemming and seaming heads, already configured in the assembling step of the machine for operating on containers and lids of different sizes, allow changing production in an extremely short timeframe and subsequently operating in the absence of errors. In fact, at every change of production it will be sufficient to change the hemming and seaming head inside the hemming and seaming station, a change that requires much less positioning precision, in the order of a few tenths, with respect to the adjustment of the position of the rollers with respect to the relative mandrel which requires, instead, precisions in the order of a few hundredths of a millimeter in order to have a hemming and seaming that is acceptable and fluid-tight.

[0015] In this manner, a machine is obtained which is cost-effective and extremely flexible, as well as easy and intuitive to manage.

[0016] The abovementioned and other purposes and advantages are achieved, according to an aspect of the invention, by a hemming and seaming machine having the characteristics defined in claim 1. Preferred embodiments of the invention are defined in the dependent claims.Brief description of the drawings

[0017] The functional and structural characteristics of some preferred embodiments of a hemming and seaming machine according to the invention will now be described. Reference is made to the accompanying drawings, wherein: Figures 1A and 1B are schematic views respectively representative of two steps of the hemming and seaming operation, wherein the series of images in Figure 1A is exemplifying of the sequence of operations in which a first roller cooperates with the respective mandrel for producing a mutual winding of the outer edge of the lid on the outer edge of the container, whereas the series of images in Figure 1B is exemplifying of the sequence of operations in which a second roller cooperates with the respective mandrel for producing a radial squashing of the outer edge of the lid on the outer edge of the container; Figure 1 illustrates, in a plan view and substantially in blocks, a plant for filling and connecting parts of a can and provided with a preferred embodiment of a hemming and seaming machine manufactured according to the principles of the present invention; Figure 2 illustrates, in a perspective view and on an enlarged scale, the hemming and seaming machine of Figure 1 arranged in a first functional condition; Figure 2A is a figure analogous to Figure 2 and illustrates the hemming and seaming machine of Figure 2 in a different functional condition; Figure 3 is a section of the hemming and seaming machine of Figures 2 and 2A, wherein an arrangement of three hemming and seaming heads is visible, according to an embodiment of the present invention; Figure 4 is a figure analogous to Figure 3 and illustrates a variant of an assembly of Figure 3, wherein an arrangement of two hemming and seaming heads is visible, according to an alternative embodiment of the present invention; and Figure 5 is a perspective schematic view of a support adapted to connect a roller to the structure of the supporting frame seen from two different angles, according to an embodiment of the present invention. Detailed description

[0018] In Figure 1, reference numeral 5 indicates, as a whole, a plant for forming or manufacturing cans 6 starting from a container 2 and from a lid 1 for closing said container 2 after being filled, for example, with a beverage.

[0019] For such purpose, the plant 5 comprises a filling assembly 7 for filling the container 2, a feeding assembly 8, schematically illustrated, for feeding the lids 1 and a hemming and seaming machine for hemming and seaming each lid 1 to an upper terminal portion 2A of a relative container 2.

[0020] With reference to Figures 2 and 2A, the machine 9 comprises a supporting frame 10, which includes an upright 12 extended along a primary axis x, and a structure 14 supported by the upright 12 in a rotatable manner around such primary axis x and in an axially fixed position during the hemming and seaming operation.

[0021] The hemming and seaming machine 9 further comprises two or more hemming and seaming heads 15 for connecting the lid 1 to the edge 2A of an underlying relative container 2, as it will be better described in the following.

[0022] In particular, according to a first embodiment illustrated in Figures 1, 2 and 3, the machine 9 comprises three hemming and seaming heads 15 independent of one another and angularly equally distanced in the surroundings of the primary axis x, i.e. spaced apart from one another by an angle equal to 120°.

[0023] According to a different embodiment illustrated in Figure 4, the machine 9 comprises two hemming and seaming heads 15 independent of one another arranged on diametrically opposite sides of the primary axis x, i.e. angularly spaced apart from one another by an angle equal to 180°.

[0024] Regardless of the number, each hemming and seaming head 15 comprises a respective mandrel 16, which is carried by the structure 14 and is rotatable around a respective secondary axis y parallel to the primary axis x. The mandrels 16 have respective operating edges (conveniently, placed on the end of the mandrel 16 adapted to come into contact with the lid 1 (Figure 2)), which are shaped for forming abutments adapted to guide the hemming and seaming of the radially outer edges of the lid 1 and the container 2. Such operating edges are conveniently configured to engage from the inside the outer edge of the lid 1 which is typically prepared so as to be arranged raised with respect to the lower face of the mandrel 16, from the face of such lid 1 facing the opposite side with respect to the container 2.

[0025] Each head 15 then comprises a respective pair of rollers 18a, 18b; 19a, 19b (Figures 2 and 2A), carried by the structure 14 and arranged alongside a relative mandrel 16 and in a predefined position.

[0026] The rollers 18a, 18b, 19a, 19b are rotating solids that have radially outer edges shaped so as to cooperate with the operating edge of the respective mandrel 16 for exerting a plastic deformation on the outer edges of a lid and a container to be assembled, according to modes known to a person skilled in the art.

[0027] Each pair of rollers 18a, 18b, 19a, 19b comprises a winding roller 18a, 19a movable from an inactive or resting position, illustrated in Figure 2A, in which such winding roller 18a, 19a is configured to avoid engaging the radially outer edges of the lid 1 and the container 2, to an operating or active position, illustrated in Figure 2, in which such winding roller 18a, 19a is configured to engage the radially outer edges of the lid 1 and the container 2; each winding roller 18a, 19a having a profile adapted to cooperate with the respective mandrel 16 for making integral and turning downwards the radially outer edges of the lid 1 and the container 2. Each pair of rollers 18a, 18b, 19a, 19b then comprises a relative squashing roller 18b, 19b, movable from a resting position (Figure 2A), in which the squashing roller (18b, 19b) is configured to avoid engaging the radially outer edges of the lid 1 and the container 2, and an operating or active position (Figure 2), in which the squashing roller 18b, 19b is configured to engage the radially outer edges of the lid 1 and the container 2; each squashing roller 18b, 19b having a profile adapted to cooperate with the respective mandrel 16 for vertically squashing and flattening the radially outer edges of the lid and the container turned by the associated winding roller 18a, 19a, when the respective squashing roller 18a, 19a is in its operating position. The squashing rollers 18b, 19b are configured to reach the respective operating position after the respective winding roller 18a, 19a has kept the respective active position for at least part of a revolution of the respective mandrel 16 around the secondary axis y, conveniently, a complete revolution.

[0028] The hemming and seaming machine 9 further has a fixed hemming and seaming station 25, which houses a single support plate 26, which is common to all the containers 2 worked on the machine 9, forms a rotatable support for the base of a container 2 and is coupled to the frame 10 in a rotatable manner around a hemming and seaming axis 26A which is fixed with respect to said frame 10.

[0029] In use, the hemming and seaming axis 26A is practically coinciding with the secondary axis y of the mandrel 16 arranged in the hemming and seaming station 25. Since only one hemming and seaming head 15 at a time is arranged in the hemming and seaming station 25, for each hemming and seaming cycle, there is only one mandrel 16 and only one pair of rollers 18a, 18b, 19a, 19b, among all the rollers 18a, 18b, 19a, 19b included in the hemming and seaming machine 9, that engages the radially outer edges of a lid 1 and a container 2. In other words, for each hemming and seaming cycle, i.e. the complete connection of the lid 1 to the container 2, only one hemming and seaming head 15 operates, whereas the remaining hemming and seaming heads 15 are inoperative as they are arranged outside the hemming and seaming station 25, as illustrated in Figures 1, 2, 2A and 4.

[0030] In the preferred embodiment having two hemming and seaming heads 15, the profile of one of the two winding rollers 18a is different from the corresponding profile of the other of the two winding rollers 19a. Additionally or alternatively, the profile of one of the two squashing rollers 18b is different from the corresponding profile of the other of the two squashing rollers 19b. Additionally or alternatively, the operating edge of one of the mandrels 16 is different from the corresponding operating edge of the other mandrel 16. Besides the foregoing, the rollers of one of the hemming and seaming heads 15 can be the same as those of the other hemming and seaming head but arranged at a radial or axial distance from the relative mandrel which is different from the radial or axial distance of the rollers of the other hemming and seaming head with respect to the respective mandrel 16. In this manner, the two hemming and seaming heads 15, i.e. the at least two assemblies formed by each mandrel 16 and by the respective pair of rollers 18a, 18b, 19a, 19b will be able to operate on container-lid assemblies also very different from one another and, in particular, different from one another as to shape and / or geometry and / or dimensions. In this manner, each of the hemming and seaming heads 15 is dedicated to a container-lid assembly of its own which is different from the other container-lid assembly on which the other hemming and seaming head 15 is dedicated to operate.

[0031] According to an embodiment, the two rollers 18a, 18b, 19a, 19b of each of the at least two pairs of rollers 18a, 18b, 19a, 19b are arranged symmetrical with respect to a plane P (Figure 4) containing the primary x and secondary y axes, each roller 18a, 18b, 19a, 19b being oscillatable from the respective resting position to the respective operating position by means of a respective arm 20 hinged to the structure 14.

[0032] Preferably, the one or more arms 20 are hinged to the structure 14 at an intermediate point between the opposite ends thereof, where the respective roller 18a, 18b, 19a, 19b is mounted at the end of the arm 20 proximal to the mandrel 16, and the end of the arm 20 distal from the mandrel 16 is operatively associated with a cam 22 rotatable around a respective tertiary axis z parallel to (or coinciding with) the primary axis x.

[0033] According to a preferred embodiment, a cam 22 which is simultaneously associated with more than one winding roller 18a, 19a and a cam 22 which is simultaneously associated with more than one squashing roller 18b, 19b are present, both cams 22 rotated by a same camshaft, coaxial to the primary axis x and rotatable around it. Conveniently, the at least two cams 22 are vertically (i.e. along the primary axis x) and / or circumferentially offset along such camshaft; suitably, the arms 20 associated with the winding rollers 18a, 19a lie on a same plane (substantially coinciding with the plane on which the cam 22 associated with such rollers lies), vertically offset with respect to the plane on which the squashing rollers 18b, 19b lie (substantially coinciding with the plane on which the cam 22 associated with such rollers lies) .

[0034] Conveniently, each mandrel 16 and / or each cam 22 is rotatable by means of an independent motor 24. Preferably, the motors 24 are carried by the structure 14.

[0035] Analogous considerations are valid in the case of three hemming and seaming heads 15 (Figure 3). In particular, the third hemming and seaming head 15 is constructively different or set in a different manner from the other two hemming and seaming heads 15 in order to work on the machine 9 a third container-lid assembly different from the other two container-lid assemblies.

[0036] According to an embodiment, the structure 14 comprises a first plate 14a firmly connected to the upper end of the upright 12, and the arms 20 comprise a vertical portion 21a which passes rotatably through said first plate 14a in an axial direction, such vertical portion connecting a first half-arm 21b, adapted to come into contact with the cam 22, to a second half-arm 21c, which carries the respective roller 18a, 18b, 19a, 19b.

[0037] Still with reference to Figure 5, for the setting of each hemming and seaming head 15, the relative rollers 18, 19 are coupled to the relative half-arm 21c by an eccentric E which allows adjusting the distance of the roller from the relative mandrel in a radial direction. Still for the setting of each hemming and seaming head 15, the relative rollers 18, 19 are further coupled to the relative half-arm 21c by a screw or tooth device F configured to vary in height the position of the roller with respect to the relative half-arm 21c, i.e. in a direction parallel to the primary axis x or to the hemming and seaming axis 26A.

[0038] Still with reference to Figures 2, 2A, the two half-arms 21b, 21c face opposite sides of the plate 14a. Conveniently, the half-arms 21b associated with the winding rollers di 18a, 19a are vertically offset (along the primary axis x) with respect to the half-arms 21b associated with the squashing rollers 18b, 19b.

[0039] Furthermore, in the entire present description and in the claims, the terms and the expressions indicating positions and orientations, such as "longitudinal", "transverse" or "vertical", refer to the longitudinal axis x.

[0040] In use, depending on the characteristics of the container-lid assembly to be worked, the structure 14 is pitch rotated around the primary axis x and one of the hemming and seaming heads 15 is carried into the forming station 25 and said structure locked on the upright 12 by a snap device 30 (Figures 2 and 2A) so that the axis y of the relative mandrel 16 substantially coincides with the hemming and seaming axis 26A, as illustrated in Figure 2A. At this point, a container 2 is carried on the plate 26 by a starry wheel 31 (Figure 1), which is arranged in the station 25 and is coupled to the frame 10 in a rotatable manner around an axis 31A parallel to the axis 26A and in an axially fixed position. The starry wheel 31 receives the containers 2 from the filling assembly 7 of the container 2. Contextually with the forward moving of the full containers 2, in the station 25 the respective lids 1 are moved forward by the assembly 8. In the station 25 or upstream thereof, a lid 1 is superimposed on the relative full container 2, then, the plate 26 with the container-lid assembly on board is raised forcing the container-lid assembly against the mandrel 16.

[0041] At this point, the container-lid assembly is rotated by the relative motor 24 and the relative rollers driven by the cams 22 to cooperate with the mandrel 16. The rotation of the container-lid assembly continues up to the completion of the hemming and seaming, then the plate 26 is lowered, the formed can 6 (Figure 1) is moved away from the station 25 by said starry wheel 31 and contextually a new container 2 with the relative lid 1 superimposed is arranged on the plate 26. The described operations are repeated forming a succession of cans 6 identical to one another. During the raising or the lowering of the plate 26 and during the entire step of hemming and seaming, the starry wheel 31 is kept still.

[0042] When it is necessary to change size, i.e. to work a container-lid assembly different from the previous container-lid assembly, the structure 14 is freed from the angular constraint with the upright 12 and pitch rotated so as to move away the previous head 15 from the station 25 and simultaneously bring the new hemming and seaming head 15 provided for working the new container-lid assembly inside the hemming and seaming station 25. Once positioned, the new hemming and seaming head 15 is locked by the assembly 30 and the production of the new cans is started following the same steps previously described.

[0043] Different aspects and embodiments of a hemming and seaming machine according to the invention have been described. In particular, the hemming and seaming machine 9 could comprise a number of hemming and seaming heads different from those described by way of example and each one configured to operate on a provided container-lid assembly of its own different from all the other container-lid assemblies worked by the other hemming and seaming heads for manufacturing cans different from one another as to shape and / or geometry and / or dimension.

[0044] Since all the hemming and seaming heads 15 are preset on the machine 9 in the assembling step of the machine 9, at every change of production the operator in charge of the machine will simply have to pitch rotate the structure 14 and bring into the hemming and seaming station 25 the hemming and seaming head corresponding to the container-lid assembly to be worked. As previously mentioned, this operation can be easily carried out by any operator in charge of the machine since the angular positions of the structure 14 are set by the snap positioning device 30 and a positioning tolerance (a few tenths) is anyway accepted or tolerated, said positioning tolerance being much greater than the positioning tolerance of the rollers (a few hundredths) with respect to the mandrel.

Examples

Embodiment Construction

[0018]In Figure 1, reference numeral 5 indicates, as a whole, a plant for forming or manufacturing cans 6 starting from a container 2 and from a lid 1 for closing said container 2 after being filled, for example, with a beverage.

[0019]For such purpose, the plant 5 comprises a filling assembly 7 for filling the container 2, a feeding assembly 8, schematically illustrated, for feeding the lids 1 and a hemming and seaming machine for hemming and seaming each lid 1 to an upper terminal portion 2A of a relative container 2.

[0020]With reference to Figures 2 and 2A, the machine 9 comprises a supporting frame 10, which includes an upright 12 extended along a primary axis x, and a structure 14 supported by the upright 12 in a rotatable manner around such primary axis x and in an axially fixed position during the hemming and seaming operation.

[0021]The hemming and seaming machine 9 further comprises two or more hemming and seaming heads 15 for connecting the lid 1 to the edge 2A of an underly...

Technical field

[0001] The present invention is placed, in general, in the sector of the equipment for bottling food liquids; in particular, the invention refers to a hemming and seaming machine, for the application of lids to cylindrical metal containers containing a food beverage.Technical note

[0002] Hemming and seaming machines adapted to apply lids to metal containers are known.

[0003] Such machines comprise a plurality of rotatable mandrels, coaxial to respective rotating plates, so that the containers, on which to apply the respective lids, are interposed between the two.

[0004] The mandrels have edges adapted to guide, during the hemming and seaming, the deformation of the outer edges of the respective lid and container, each mandrel cooperating with a pair of rollers having different circumferential profiles, so that, alternatively approaching the two rollers to the mandrel in radial direction, the outer edges of the lid and of the container, constricted between the roller and the mandrel, undergo a plastic deformation in two steps.

[0005] In a first step of the hemming and seaming cycle, as for example illustrated in the sequence of images shown in Figure 1A, the outer edges of the lid and of the container are superimposed and turned downwards outside the container (effectively being curled so that the part of the outer edge of the lid is underneath the outer edge of the container).

[0006] In a second step of the hemming and seaming cycle, the edges curled in such manner of the lid and of the container are radially squashed, so as to become at least in part parallel to the outer wall of the container (as for example illustrated in the sequence of images shown in Figure 1B).

[0007] Typically, a hemming and seaming machine comprises a plurality of mandrels and plates all carried by a ring carousel for moving along a circular hemming and seaming path; a pair of rollers carried by the carousel as well being associated with each mandrel.

[0008] Such a configuration lends itself very well for mass production, since it offers the possibility of simultaneously working a plurality of containers, thus ensuring a high production volume.

[0009] However, such a machine is costly (as regards both purchase and maintenance) and functionally very rigid, therefore it is not suitable for small lot productions (for example, in the case of artisan producers), especially when it is necessary to change size, i.e. when the machine has to operate on containers and lids different from one another as to geometry and / or dimensions. In fact, changing size on a machine of this type entails the disassembling thereof and / or the replacement of all or part of the rollers and / or the change of all the mandrels, with a great waste of time and high intervention costs, since it requires the presence of personnel technically qualified to dismantle and reconfigure the machine, the latter operations being particularly complex, especially because they require the repositioning of the rollers with respect to the mandrels which has to be carried out respecting tolerances in the order of a few hundredths of a millimeter, tolerances difficult to obtain by a medium-small sized producer that generally does not have a sufficient preparation for obtaining a similar level of precision, unlike the producer of the same machine.

[0010] Such limitations, understandably, prejudice the possibility of using a hemming and seaming machine of a known type in the productions of small series and thus with frequent production changes. The above hemming and seaming machines are disclosed in WO 2019 / 004947 A1, which is considered to form the basis for the preamble of claim 1, in US 2 467 154 A and in US 2 737 137 A.Summary of the invention

[0011] An object of the present invention is to overcome the abovementioned problems.

[0012] In order to obtain such result, a hemming and seaming machine according to the present invention comprises a supporting frame, equipped with at least two hemming and seaming heads each one having a forming mandrel and a pair of rollers each one cooperating with the relative mandrel.

[0013] A single work station is also present comprising a single rotating plate adapted to form a base rotatable around a fixed axis for a container on which to apply a lid. The machine is configured to carry the mandrel of only one of the two hemming and seaming heads in a position coaxial to such rotating plate, so that the hemming and seaming machine can assemble a lid to only one container at a time. In other words, the hemming and seaming machine is configured so that, while a single mandrel cooperates with the rotating plate in the hemming and seaming of a lid to a container, the other mandrels of the other hemming and seaming heads do not operate on any container, no further rotating plates being associated with such mandrels in the hemming and seaming station. The exchange of the hemming and seaming heads inside the hemming and seaming station allows carrying a different mandrel and / or different rollers or the same rollers arranged in different positions with respect to the mandrel at the rotating plate, so as to be able to operate with a different mandrel / rollers assembly.

[0014] The two hemming and seaming heads, already configured in the assembling step of the machine for operating on containers and lids of different sizes, allow changing production in an extremely short timeframe and subsequently operating in the absence of errors. In fact, at every change of production it will be sufficient to change the hemming and seaming head inside the hemming and seaming station, a change that requires much less positioning precision, in the order of a few tenths, with respect to the adjustment of the position of the rollers with respect to the relative mandrel which requires, instead, precisions in the order of a few hundredths of a millimeter in order to have a hemming and seaming that is acceptable and fluid-tight.

[0015] In this manner, a machine is obtained which is cost-effective and extremely flexible, as well as easy and intuitive to manage.

[0016] The abovementioned and other purposes and advantages are achieved, according to an aspect of the invention, by a hemming and seaming machine having the characteristics defined in claim 1. Preferred embodiments of the invention are defined in the dependent claims.Brief description of the drawings

[0017] The functional and structural characteristics of some preferred embodiments of a hemming and seaming machine according to the invention will now be described. Reference is made to the accompanying drawings, wherein: Figures 1A and 1B are schematic views respectively representative of two steps of the hemming and seaming operation, wherein the series of images in Figure 1A is exemplifying of the sequence of operations in which a first roller cooperates with the respective mandrel for producing a mutual winding of the outer edge of the lid on the outer edge of the container, whereas the series of images in Figure 1B is exemplifying of the sequence of operations in which a second roller cooperates with the respective mandrel for producing a radial squashing of the outer edge of the lid on the outer edge of the container; Figure 1 illustrates, in a plan view and substantially in blocks, a plant for filling and connecting parts of a can and provided with a preferred embodiment of a hemming and seaming machine manufactured according to the principles of the present invention; Figure 2 illustrates, in a perspective view and on an enlarged scale, the hemming and seaming machine of Figure 1 arranged in a first functional condition; Figure 2A is a figure analogous to Figure 2 and illustrates the hemming and seaming machine of Figure 2 in a different functional condition; Figure 3 is a section of the hemming and seaming machine of Figures 2 and 2A, wherein an arrangement of three hemming and seaming heads is visible, according to an embodiment of the present invention; Figure 4 is a figure analogous to Figure 3 and illustrates a variant of an assembly of Figure 3, wherein an arrangement of two hemming and seaming heads is visible, according to an alternative embodiment of the present invention; and Figure 5 is a perspective schematic view of a support adapted to connect a roller to the structure of the supporting frame seen from two different angles, according to an embodiment of the present invention. Detailed description

[0018] In Figure 1, reference numeral 5 indicates, as a whole, a plant for forming or manufacturing cans 6 starting from a container 2 and from a lid 1 for closing said container 2 after being filled, for example, with a beverage.

[0019] For such purpose, the plant 5 comprises a filling assembly 7 for filling the container 2, a feeding assembly 8, schematically illustrated, for feeding the lids 1 and a hemming and seaming machine for hemming and seaming each lid 1 to an upper terminal portion 2A of a relative container 2.

[0020] With reference to Figures 2 and 2A, the machine 9 comprises a supporting frame 10, which includes an upright 12 extended along a primary axis x, and a structure 14 supported by the upright 12 in a rotatable manner around such primary axis x and in an axially fixed position during the hemming and seaming operation.

[0021] The hemming and seaming machine 9 further comprises two or more hemming and seaming heads 15 for connecting the lid 1 to the edge 2A of an underlying relative container 2, as it will be better described in the following.

[0022] In particular, according to a first embodiment illustrated in Figures 1, 2 and 3, the machine 9 comprises three hemming and seaming heads 15 independent of one another and angularly equally distanced in the surroundings of the primary axis x, i.e. spaced apart from one another by an angle equal to 120°.

[0023] According to a different embodiment illustrated in Figure 4, the machine 9 comprises two hemming and seaming heads 15 independent of one another arranged on diametrically opposite sides of the primary axis x, i.e. angularly spaced apart from one another by an angle equal to 180°.

[0024] Regardless of the number, each hemming and seaming head 15 comprises a respective mandrel 16, which is carried by the structure 14 and is rotatable around a respective secondary axis y parallel to the primary axis x. The mandrels 16 have respective operating edges (conveniently, placed on the end of the mandrel 16 adapted to come into contact with the lid 1 (Figure 2)), which are shaped for forming abutments adapted to guide the hemming and seaming of the radially outer edges of the lid 1 and the container 2. Such operating edges are conveniently configured to engage from the inside the outer edge of the lid 1 which is typically prepared so as to be arranged raised with respect to the lower face of the mandrel 16, from the face of such lid 1 facing the opposite side with respect to the container 2.

[0025] Each head 15 then comprises a respective pair of rollers 18a, 18b; 19a, 19b (Figures 2 and 2A), carried by the structure 14 and arranged alongside a relative mandrel 16 and in a predefined position.

[0026] The rollers 18a, 18b, 19a, 19b are rotating solids that have radially outer edges shaped so as to cooperate with the operating edge of the respective mandrel 16 for exerting a plastic deformation on the outer edges of a lid and a container to be assembled, according to modes known to a person skilled in the art.

[0027] Each pair of rollers 18a, 18b, 19a, 19b comprises a winding roller 18a, 19a movable from an inactive or resting position, illustrated in Figure 2A, in which such winding roller 18a, 19a is configured to avoid engaging the radially outer edges of the lid 1 and the container 2, to an operating or active position, illustrated in Figure 2, in which such winding roller 18a, 19a is configured to engage the radially outer edges of the lid 1 and the container 2; each winding roller 18a, 19a having a profile adapted to cooperate with the respective mandrel 16 for making integral and turning downwards the radially outer edges of the lid 1 and the container 2. Each pair of rollers 18a, 18b, 19a, 19b then comprises a relative squashing roller 18b, 19b, movable from a resting position (Figure 2A), in which the squashing roller (18b, 19b) is configured to avoid engaging the radially outer edges of the lid 1 and the container 2, and an operating or active position (Figure 2), in which the squashing roller 18b, 19b is configured to engage the radially outer edges of the lid 1 and the container 2; each squashing roller 18b, 19b having a profile adapted to cooperate with the respective mandrel 16 for vertically squashing and flattening the radially outer edges of the lid and the container turned by the associated winding roller 18a, 19a, when the respective squashing roller 18a, 19a is in its operating position. The squashing rollers 18b, 19b are configured to reach the respective operating position after the respective winding roller 18a, 19a has kept the respective active position for at least part of a revolution of the respective mandrel 16 around the secondary axis y, conveniently, a complete revolution.

[0028] The hemming and seaming machine 9 further has a fixed hemming and seaming station 25, which houses a single support plate 26, which is common to all the containers 2 worked on the machine 9, forms a rotatable support for the base of a container 2 and is coupled to the frame 10 in a rotatable manner around a hemming and seaming axis 26A which is fixed with respect to said frame 10.

[0029] In use, the hemming and seaming axis 26A is practically coinciding with the secondary axis y of the mandrel 16 arranged in the hemming and seaming station 25. Since only one hemming and seaming head 15 at a time is arranged in the hemming and seaming station 25, for each hemming and seaming cycle, there is only one mandrel 16 and only one pair of rollers 18a, 18b, 19a, 19b, among all the rollers 18a, 18b, 19a, 19b included in the hemming and seaming machine 9, that engages the radially outer edges of a lid 1 and a container 2. In other words, for each hemming and seaming cycle, i.e. the complete connection of the lid 1 to the container 2, only one hemming and seaming head 15 operates, whereas the remaining hemming and seaming heads 15 are inoperative as they are arranged outside the hemming and seaming station 25, as illustrated in Figures 1, 2, 2A and 4.

[0030] In the preferred embodiment having two hemming and seaming heads 15, the profile of one of the two winding rollers 18a is different from the corresponding profile of the other of the two winding rollers 19a. Additionally or alternatively, the profile of one of the two squashing rollers 18b is different from the corresponding profile of the other of the two squashing rollers 19b. Additionally or alternatively, the operating edge of one of the mandrels 16 is different from the corresponding operating edge of the other mandrel 16. Besides the foregoing, the rollers of one of the hemming and seaming heads 15 can be the same as those of the other hemming and seaming head but arranged at a radial or axial distance from the relative mandrel which is different from the radial or axial distance of the rollers of the other hemming and seaming head with respect to the respective mandrel 16. In this manner, the two hemming and seaming heads 15, i.e. the at least two assemblies formed by each mandrel 16 and by the respective pair of rollers 18a, 18b, 19a, 19b will be able to operate on container-lid assemblies also very different from one another and, in particular, different from one another as to shape and / or geometry and / or dimensions. In this manner, each of the hemming and seaming heads 15 is dedicated to a container-lid assembly of its own which is different from the other container-lid assembly on which the other hemming and seaming head 15 is dedicated to operate.

[0031] According to an embodiment, the two rollers 18a, 18b, 19a, 19b of each of the at least two pairs of rollers 18a, 18b, 19a, 19b are arranged symmetrical with respect to a plane P (Figure 4) containing the primary x and secondary y axes, each roller 18a, 18b, 19a, 19b being oscillatable from the respective resting position to the respective operating position by means of a respective arm 20 hinged to the structure 14.

[0032] Preferably, the one or more arms 20 are hinged to the structure 14 at an intermediate point between the opposite ends thereof, where the respective roller 18a, 18b, 19a, 19b is mounted at the end of the arm 20 proximal to the mandrel 16, and the end of the arm 20 distal from the mandrel 16 is operatively associated with a cam 22 rotatable around a respective tertiary axis z parallel to (or coinciding with) the primary axis x.

[0033] According to a preferred embodiment, a cam 22 which is simultaneously associated with more than one winding roller 18a, 19a and a cam 22 which is simultaneously associated with more than one squashing roller 18b, 19b are present, both cams 22 rotated by a same camshaft, coaxial to the primary axis x and rotatable around it. Conveniently, the at least two cams 22 are vertically (i.e. along the primary axis x) and / or circumferentially offset along such camshaft; suitably, the arms 20 associated with the winding rollers 18a, 19a lie on a same plane (substantially coinciding with the plane on which the cam 22 associated with such rollers lies), vertically offset with respect to the plane on which the squashing rollers 18b, 19b lie (substantially coinciding with the plane on which the cam 22 associated with such rollers lies) .

[0034] Conveniently, each mandrel 16 and / or each cam 22 is rotatable by means of an independent motor 24. Preferably, the motors 24 are carried by the structure 14.

[0035] Analogous considerations are valid in the case of three hemming and seaming heads 15 (Figure 3). In particular, the third hemming and seaming head 15 is constructively different or set in a different manner from the other two hemming and seaming heads 15 in order to work on the machine 9 a third container-lid assembly different from the other two container-lid assemblies.

[0036] According to an embodiment, the structure 14 comprises a first plate 14a firmly connected to the upper end of the upright 12, and the arms 20 comprise a vertical portion 21a which passes rotatably through said first plate 14a in an axial direction, such vertical portion connecting a first half-arm 21b, adapted to come into contact with the cam 22, to a second half-arm 21c, which carries the respective roller 18a, 18b, 19a, 19b.

[0037] Still with reference to Figure 5, for the setting of each hemming and seaming head 15, the relative rollers 18, 19 are coupled to the relative half-arm 21c by an eccentric E which allows adjusting the distance of the roller from the relative mandrel in a radial direction. Still for the setting of each hemming and seaming head 15, the relative rollers 18, 19 are further coupled to the relative half-arm 21c by a screw or tooth device F configured to vary in height the position of the roller with respect to the relative half-arm 21c, i.e. in a direction parallel to the primary axis x or to the hemming and seaming axis 26A.

[0038] Still with reference to Figures 2, 2A, the two half-arms 21b, 21c face opposite sides of the plate 14a. Conveniently, the half-arms 21b associated with the winding rollers di 18a, 19a are vertically offset (along the primary axis x) with respect to the half-arms 21b associated with the squashing rollers 18b, 19b.

[0039] Furthermore, in the entire present description and in the claims, the terms and the expressions indicating positions and orientations, such as "longitudinal", "transverse" or "vertical", refer to the longitudinal axis x.

[0040] In use, depending on the characteristics of the container-lid assembly to be worked, the structure 14 is pitch rotated around the primary axis x and one of the hemming and seaming heads 15 is carried into the forming station 25 and said structure locked on the upright 12 by a snap device 30 (Figures 2 and 2A) so that the axis y of the relative mandrel 16 substantially coincides with the hemming and seaming axis 26A, as illustrated in Figure 2A. At this point, a container 2 is carried on the plate 26 by a starry wheel 31 (Figure 1), which is arranged in the station 25 and is coupled to the frame 10 in a rotatable manner around an axis 31A parallel to the axis 26A and in an axially fixed position. The starry wheel 31 receives the containers 2 from the filling assembly 7 of the container 2. Contextually with the forward moving of the full containers 2, in the station 25 the respective lids 1 are moved forward by the assembly 8. In the station 25 or upstream thereof, a lid 1 is superimposed on the relative full container 2, then, the plate 26 with the container-lid assembly on board is raised forcing the container-lid assembly against the mandrel 16.

[0041] At this point, the container-lid assembly is rotated by the relative motor 24 and the relative rollers driven by the cams 22 to cooperate with the mandrel 16. The rotation of the container-lid assembly continues up to the completion of the hemming and seaming, then the plate 26 is lowered, the formed can 6 (Figure 1) is moved away from the station 25 by said starry wheel 31 and contextually a new container 2 with the relative lid 1 superimposed is arranged on the plate 26. The described operations are repeated forming a succession of cans 6 identical to one another. During the raising or the lowering of the plate 26 and during the entire step of hemming and seaming, the starry wheel 31 is kept still.

[0042] When it is necessary to change size, i.e. to work a container-lid assembly different from the previous container-lid assembly, the structure 14 is freed from the angular constraint with the upright 12 and pitch rotated so as to move away the previous head 15 from the station 25 and simultaneously bring the new hemming and seaming head 15 provided for working the new container-lid assembly inside the hemming and seaming station 25. Once positioned, the new hemming and seaming head 15 is locked by the assembly 30 and the production of the new cans is started following the same steps previously described.

[0043] Different aspects and embodiments of a hemming and seaming machine according to the invention have been described. In particular, the hemming and seaming machine 9 could comprise a number of hemming and seaming heads different from those described by way of example and each one configured to operate on a provided container-lid assembly of its own different from all the other container-lid assemblies worked by the other hemming and seaming heads for manufacturing cans different from one another as to shape and / or geometry and / or dimension.

[0044] Since all the hemming and seaming heads 15 are preset on the machine 9 in the assembling step of the machine 9, at every change of production the operator in charge of the machine will simply have to pitch rotate the structure 14 and bring into the hemming and seaming station 25 the hemming and seaming head corresponding to the container-lid assembly to be worked. As previously mentioned, this operation can be easily carried out by any operator in charge of the machine since the angular positions of the structure 14 are set by the snap positioning device 30 and a positioning tolerance (a few tenths) is anyway accepted or tolerated, said positioning tolerance being much greater than the positioning tolerance of the rollers (a few hundredths) with respect to the mandrel.

Examples

Embodiment Construction

[0018]In Figure 1, reference numeral 5 indicates, as a whole, a plant for forming or manufacturing cans 6 starting from a container 2 and from a lid 1 for closing said container 2 after being filled, for example, with a beverage.

[0019]For such purpose, the plant 5 comprises a filling assembly 7 for filling the container 2, a feeding assembly 8, schematically illustrated, for feeding the lids 1 and a hemming and seaming machine for hemming and seaming each lid 1 to an upper terminal portion 2A of a relative container 2.

[0020]With reference to Figures 2 and 2A, the machine 9 comprises a supporting frame 10, which includes an upright 12 extended along a primary axis x, and a structure 14 supported by the upright 12 in a rotatable manner around such primary axis x and in an axially fixed position during the hemming and seaming operation.

[0021]The hemming and seaming machine 9 further comprises two or more hemming and seaming heads 15 for connecting the lid 1 to the edge 2A of an underly...

Claims

1. A hemming and seaming machine (9) for hemming and seaming a lid to a container; the hemming and seaming machine (9) comprising: - a supporting frame (10), in turn, comprising an upright (12) extended along a primary axis (x), and a structure (14) supported by the upright (12) and coupled to the upright in a rotatable manner around said primary axis (x) ; - at least a first and at least a second hemming and seaming head (15) independent of one another carried by the structure (14) in positions angularly spaced apart around said primary axis (x) each one to make integral with one another a peripheral edge (2A) of a container (2) with a peripheral edge of the lid (1); each hemming and seaming head (15) comprising a respective mandrel (16) rotatable around a respective secondary axis (y) and parallel to the primary axis (x); said mandrels (16) having respective operating edges, which are shaped in such a way as to form abutments adapted to guide the hemming and seaming of the radially outer edges of the lid and the container; each said hemming and seaming head further comprising a respective pair of rollers (18a, 18b, 19a, 19b) alongside the respective mandrel (16); each pair of rollers comprising: - a winding roller (18a, 19a), movable from a distanced resting position, in which said winding roller (18a, 19a) is configured to avoid engaging the radially outer edges of the lid and the container, to an operating position, in which said winding roller (18a, 19a) is configured to engage the radially outer edges of the lid and the container, said winding roller (18a, 19a) having a profile adapted to cooperate with the respective mandrel (16) to make integral and turn the radially outer edges of the lid and container; and - a squashing roller (18b, 19b), movable from a resting position, in which said squashing roller (18b, 19b) is configured to avoid engaging the radially outer edges of the lid and the container, to an operating position, in which said squashing roller (18b, 19b) is configured to engage the radially outer edges of the lid and the container, said squashing roller (18b, 19b) having a profile adapted to cooperate with the respective mandrel (16); characterized in that the hemming and seaming machine (9) comprises a hemming and seaming station (25) and a single support plate (26) common to all the containers (2) arranged in said hemming and seaming station (25) and coupled to said supporting frame (10) in a rotatable manner around a hemming and seaming axis (26A) which is fixed with respect to said supporting frame (10) and slidable along the hemming and seaming axis (26A); releasable angular constraining means (30) being provided to allow a pitch rotation of said support structure (14) with respect to said supporting frame (10) and to the plate (26) around said primary axis (x) and hold the one or the other of said hemming and seaming heads (15) in said station (25) with the secondary axis (Y) of the relative mandrel (16) substantially coinciding with said fixed hemming and seaming axis (26A).

2. A machine according to claim 1, characterized in that the first of said hemming and seaming heads is set in a different manner from said second hemming and seaming head to work a first container-lid assembly different from a second container-lid assembly workable by said second hemming and seaming head.

3. A machine according to claim 1 or 2, characterized in that, when arranged in their operating position, the rollers of one of said hemming and seaming heads (15) are arranged at a radial or axial distance from the relative mandrel (16) which is different from the radial or axial distance of the rollers of the other hemming and seaming head with respect to the respective said mandrel (16).

4. A machine according to any one of the preceding claims, characterized in that the profile of the mandrel of one of said hemming and seaming heads is different from the profile of the mandrel of the other hemming and seaming head.

5. A machine according to any one of the preceding claims, wherein the profile of the winding roller (18a) of one of said hemming and seaming heads is different from the profile of the winding roller (19a) of the other hemming and seaming head.

6. A machine according to any one of the preceding claims, wherein the profile of the pressing roller (18b) of one of the hemming and seaming heads is different from the profile of the pressing roller (19b) of the other hemming and seaming head.

7. A machine according to any one of the preceding claims, characterized in that said hemming and seaming station (25) further houses a single wheel (31) for loading the containers (2) in succession on the plate (26) and for unloading the containers closed by the plate (26); said wheel (31) being rotatable around a fixed axis (31A) parallel to said hemming and seaming axis (26A).

8. A machine according to claim 7, characterized in that said plate (26) is rotatable around, and vertically slidable along, said hemming and seaming axis (26A) with respect to the wheel (31) for loading / unloading and to the corresponding hemming and seaming head (15).

9. A machine according to any one of the preceding claims, wherein the two rollers (18a, 18b, 19a, 19b) of each of said hemming and seaming heads (15) are arranged symmetrical with respect to a plane (P) containing the primary (x), secondary (y) and hemming and seaming (26A) axes, and wherein each roller (18a, 18b, 19a, 19b) is oscillatable from the respective resting position to the respective operating position by means of a respective arm (20) hinged to said structure (14).

10. A machine according to claim 9, wherein one or more arms (20) are hinged to said structure (14) at an intermediate point between the opposite ends thereof, the respective roller (18a, 18b, 19a, 19b) being mounted at the end of the arm (20) proximal to the mandrel (16), the end of the arm (20) distal from the mandrel (16) being operatively associated with a cam (22), rotatable around a respective tertiary axis (z) parallel to the primary axis (x) and to the hemming and seaming axis.

11. A machine according to claim 10, wherein there is a cam (22) which is simultaneously associated with more than one winding roller (18a, 19a) and a cam (22) which is simultaneously associated with more than one squashing roller (18b, 19b), both cams (22) being rotated by a same camshaft, coaxial to the primary axis (x) and rotatable around it.

12. A machine according to claim 11, wherein the at least two cams (22) are offset along the primary axis (x) and / or circumferentially along said camshaft, and wherein the arms (20) associated with the winding rollers (18a, 19a) lie on a same plane vertically offset with respect to the plane on which the squashing rollers (18b, 19b) lie.

13. A machine according to one of the claims from 10 to 12, wherein each mandrel (16) and / or each cam (22) is rotatable by means of an independent motor (24).

14. A machine according to claim 13, wherein the motors (24) are carried by said structure (14).

15. A machine according to any one of the preceding claims, wherein said first and second hemming and seaming heads are arranged on diametrically opposite sides with respect to the primary axis (x).

16. A machine according to any one of the claims from 1 to 14, characterized in that it comprises a third hemming and seaming head (15) configured to work a container-lid assembly different from the container-lid assemblies workable by said first and second hemming and seaming heads; said hemming and seaming heads being distributed in the surroundings of said primary axis (x).

17. A machine according to any one of the claims from 9 to 14, wherein said structure (14) comprises a first plate (14a) surrounding the upright (12), and wherein the arms (20) comprise a vertical portion (21a) which passes rotatably through said first plate (14a) in an axial direction, said vertical portion connecting a first half-arm (21b), adapted to come into contact with the cam (22), to a second half-arm (21c), which carries the respective roller (18a, 18b, 19a, 19b), the two half-arms (21b, 21c) facing axially opposite sides of the first plate (14a).

18. A machine according to claim 17, wherein the half-arms (21b) associated with the winding rollers (18a, 19a) are vertically offset along the primary axis (x) with respect to the half-arms (21b) associated with the squashing rollers (18b, 19b).

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