A folding unit for folding and gluing opposite closing flaps of a head of boxes in a tubular configuration

Abstract

The folding unit (100) carries out the reciprocal folding and gluing of a first flap (L1) and a second flap (L2), opposite the first flap (L1), present in a head of boxes (A) in tubular configuration which are supplied along an infeed line (V).

Description

[0001] A FOLDING UNIT FOR FOLDING AND GLUING OPPOSITE CLOSING FLAPS OF A HEAD OF BOXES IN A TUBULAR CONFIGURATION

[0002] DESCRIPTION

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to the technical sector relating to the packaging of products internally of boxes.

[0005] In particular, the invention relates to a folding unit for carrying out the folding and gluing of opposite closing flaps which are present in the heads of boxes of tubular shape, once the boxes have been filled with relative products.

[0006] A particular type of boxes used for packing products is conformed in such a was as to comprise, once opened out into a tubular configuration, two open heads, in which, in at least one of the two open heads, there are present a first closing flap, hinged by a respective first fold line, and an end edge of a first face of the box, and a second closing flap, hinged by means of a respective second fold line, to an end edge of a second face of the box, opposite the first face.

[0007] DESCRIPTION OF THE PRIOR ART

[0008] The first closing flap, and the second closing flap project usually have a dimension (area) substantially corresponding to the dimensions (area) of the open head of the box in a tubular configuration which is to be closed and, when the box is opened out into the tubular configuration, the first closing flap is in a configuration that is substantially coplanar to the first face of the box to which it is hinged, and the second closing flap is substantially coplanar to the second face of the second closing flap of the box to which it is hinged.

[0009] For the closure of the head of the box in tubular configuration, the first closing flap must be folded with respect to the first face to which the first closing flap is hinged by means of a rotation thereof of substantially 90° so as to be brought into a first folding position in which it is facing the head of the box in tubular configuration (by the term “first” it is meant that the flap, between the two opposite flaps which are to be reciprocally folded and glued for the closure of the head, which is folded “first”).

[0010] Then, glue is applied on the first closing flap, thus folded, after which the second closing flap is folded with respect to the second face to which it is hinged by means of a rotation thereof substantially by 90° in order to be brought into a second folding position in which it is facing and in contact against the first closing flap, as specified in the foregoing, and on which glue has been applied, to close the head with the reciprocal gluing between the first closing flap and the second closing flap.

[0011] Figures 1 and 2 illustrate two possible sequences and modes of folding and gluing of a first closing flap (L1) and a second closing flap (L2), for closing a head (A) of boxes (A) in tubular configuration while the boxes (T) in tubular configuration are infed and advanced along an infeed line (V), and positioned time by time in stop positions (S1, S2).

[0012] Figure 1 illustrates a situation in which the first closing flap (L1) is hinged to a respective first upper face (F1) of the box (T) in tubular configuration, while the second closing flap (L2) is hinged to a respective second lower face (F2) of the box (T) in tubular configuration.

[0013] In this situation, the boxes (T) in tubular configuration are fed along an infeed line (V) and a box (T) in tubular configuration, a relative head of which is to be closed, is stopped in a first stop position (S1).

[0014] Then, the first closing flap (L1) is folded downwards, with respect to the first upper face (F1) of the box (T) in tubular configuration to which the first closing flap is hinged, by a rotation by 90° in order to be brought into a first folding position in which the flap is arranged facing the head (A) of the box (T) in tubular configuration.

[0015] Then, glue is applied on the thus-folded first closing flap (L1).

[0016] Thereafter, the box (T) in tubular configuration, with the first closing flap (L1) folded, is advanced along the infeed line (V) and positioned in a second stop position (S2).

[0017] The second closing flap (L2) is then folded upwards, with respect to the second lower face (F2) of the box (T) in tubular configuration to which the second closing flap is hinged, by a rotation by 90° in order to be brought into a second folding position in which it is arranged facing and in contact against the folded first closing flap (L1), to close the head (A) of the box (T) in tubular configuration by means of reciprocal gluing between the first closing flap (L1), and the second closing flap (L2)

[0018] Lastly, the box (T) in tubular configuration, with the respective head closed following the folding and reciprocal gluing of the first (L1) and second (L2) closing flap, is further advanced along the infeed line (V).

[0019] Figure 2 illustrates a situation in which the first closing flap (L1) is instead hinged to a respective first lower face (F1) of the box (T) in tubular configuration, while the second closing flap (L2) is hinged to a respective second upper face (F2) of the box (T) in tubular configuration.

[0020] In this situation, the boxes (T) in tubular configuration are fed along an infeed line (V) and a box (T) in tubular configuration, a relative head of which is to be closed, is stopped in a first stop position (S1).

[0021] Then, the first closing flap (L1) is folded upwards, with respect to the first lower face (F1) of the box (T) in a tubular configuration to which the first flap it is hinged, by a rotation by 90° in order to be brought into a first folding position in which the flap is arranged facing the head (A) of the box (T) in tubular configuration.

[0022] Then, glue is applied on the thus-folded first closing flap (L1).

[0023] Thereafter, the box (T) in tubular configuration, with the first closing flap (L1) folded, is advanced along the infeed line (V) and positioned in a second stop position (S2).

[0024] The second closing flap (L2) is then folded downwards, with respect to the second upper face (F2) of the box (T) in tubular configuration to which the second closing flap is hinged, by a rotation by 90° in order to be brought into a second folding position in which it is arranged facing and in contact against the folded first closing flap (L1), to close the head (A) of the box (T) in tubular configuration by mutual gluing between the first closing flap (L1), and the second closing flap (L2).

[0025] Lastly, the box (T) in tubular configuration, with the respective head closed following the folding and reciprocal gluing of the first (L1) and second (L2) closing flap, is further advanced along the infeed line (V).

[0026] At present, in the prior art, to carry out the folding sequence of the first closing flap and then, thereafter, of the second closing flap, both in a case in which the first closing flap is hinged to a lower face and when an upper face of the boxes in tubular configuration, two distinct folding units are used.

[0027] A first folding unit is used to carry out the folding of the first closing flap with respect to the first face of the box in tubular configuration to which the second closing flap is hinged, while a second folding unit is used to carry out the folding of the second closing flap with respect to the second face of the box in tubular configuration to which it is hinged.

[0028] The first folding unit and the second folding unit are arranged and positioned in two distinct working positions which can usually be located on opposite sides, with respect to the infeed direction of the boxes in tubular configuration, respectively at the first stop position and the second stop position in which the boxes in tubular configuration are time by time positioned for the folding of the two closing flaps.

[0029] Glue application means are associated to the first folding unit, which means are arranged and configured to apply glue on the first closing flap once folded in the first folding position facing the head (A) of the box (T).

[0030] At present, in the prior art, in a possible embodiment, the first folding unit and the second folding unit are realised in the following way.

[0031] The first folding unit comprises a first drive shaft which is activatable in rotation about a first horizontal axis and a first flat cam, which is coaxially mounted on the first drive shaft in order to be driven in rotation about the first horizontal rotation axis, for moving a first folding element in a vertical direction.

[0032] The first flat cam comprises, on a face thereof, a first annular channel and the first folding element is borne by a first kinematism which is connected, by means of a first roller, to the first annular channel of the first flat cam.

[0033] The first annular channel is conformed in such a way that when the first drive shaft performs a complete rotation, the first flat cam also carries out a complete rotation about the first horizontal rotation axis, and the first roller internally of the first annular channel performs a complete sliding cycle internally of the first annular channel which causes the first folding element to perform, by means of the first kinematism, a complete vertical oscillation.

[0034] In this regard, the first kinematism is configured so as to cause the first folding element to perform a complete oscillation in a vertical direction at each complete rotation of the first drive shaft, and therefore of the first flat cam, i.e. at each complete sliding cycle of the first roller internally of the first annular channel.

[0035] In this way, the first folding element can perform a complete oscillation in a vertical direction and be used to carry out the folding of the first closing flap with respect to the first face of the box in tubular configuration to which the first closing flap is hinged, and position it, by means of a rotation thereof by 90°, in the first folding position facing the open head of the box.

[0036] For example, in a case in which the first closing flap (L1) is hinged to a first upper face (F1) of the boxes (T) in tubular configuration (as illustrated in figure 1), then the first channel of the first flat cam, and the first kinematism which connects the first folding element to the first roller present in the first channel of the first flat cam, will be configured in such a way that, following a complete rotation of the first drive shaft, the first folding element will carry out a first vertical translation downwards, in order to fold the first closing flap (L1) downwards, and, therefore, once the folding the first closing flap has been completed, a second vertical translation upwards to return to the start position.

[0037] Instead, in a case in which the first closing flap (L1) is hinged to a first lower face (F2) of the boxes (T) in tubular configuration (as illustrated in figure 2), then the first channel of the first flat cam, and the first kinematism which connects the first folding element to the first roller present in the first channel of the first flat cam, will be configured in such a way that, following a complete rotation of the first drive shaft, the first folding element will carry out a first vertical translation in an upwards direction, in order to fold the first closing flap (L1) upwards and therefore, once the folding the first closing flap has been completed, will carry out a second vertical translation downwards to return to the starting position.

[0038] The second folding unit can be made substantially in the same way, and it comprises, in turn, a second drive shaft, activatable in rotation about a second horizontal rotation axis, and a second flat cam, coaxially mounted on the second drive shaft and activatable in rotation about the second horizontal rotation axis following the activation in rotation of the second drive shaft, for moving a second folding element in a vertical direction.

[0039] The second flat cam comprises, on a face thereof, a second annular channel and the second folding element is borne by a second kinematism which is connected, by a second roller, to the second annular channel of the second flat cam.

[0040] The second annular channel is conformed in such a way that when the second drive shaft performs a complete rotation, the second flat cam also carries out a complete rotation about the second horizontal rotation axis, and the second roller internally of the second annular channel performs a complete sliding cycle internally of the second annular channel which causes the second folding element to perform, by means of the second kinematism, a complete vertical oscillation.

[0041] In this regard, the second kinematism is configured so as to cause the second folding element to perform a complete oscillation in a vertical direction at each complete rotation of the second drive shaft, and therefore of the second flat cam, i.e. at each complete sliding cycle of the second roller internally of the second annular channel.

[0042] In this way, the second folding element can perform a complete oscillation in a vertical direction and be used to carry out the folding of the second closing flap with respect to the second face of the box in tubular configuration to which the it is hinged, and position it, by means of a rotation thereof by 90°, in the second folding position facing and in contact against the first folding flap, previously folded and on which glue has been applied, for the reciprocal gluing and closing of the head of the box.

[0043] For example, in a case in which the second closing flap (L2) is hinged to a second lower face (F2) of the boxes (T) in tubular configuration (as illustrated in figure 1), then the second channel of the second flat cam, and the second kinematism which connects the second folding element to the second roller present in the second channel of the second flat cam, will be configured in such a way that, following a complete rotation of the second drive shaft, the second folding element will carry out a first vertical translation in an upwards direction, in order to fold the second closing flap (L2) upwards, and, therefore, once the folding the second closing flap has been completed, a second vertical translation downwards to return to the start position.

[0044] Instead, in a case in which the second closing flap (L2) is hinged to a second upper face (F2) of the boxes (T) in tubular configuration (as illustrated in figure 2), then the second channel of the second flat cam, and the second kinematism which connects the second folding element to the second roller present in the second channel of the second flat cam, will be configured in such a way that, following a complete rotation of the second drive shaft, the second folding element will carry out a first vertical translation downwards, in order to fold the second closing flap (L2) downwards and therefore, once the folding the second closing flap has been completed, will carry out a second vertical translation upwards to return to the starting position.

[0045] The use of two distinct folding units has, however, some drawbacks.

[0046] Firstly, the units present a considerable volume by the side of the advancement line of the boxes.

[0047] Further, in a case of size change of the boxes, the operations of regulating and possibly changing components can require a great deal of time as they must be carried out on two distinct folding units.

[0048] SUMMARY OF THE INVENTION The aim of the present invention is therefore to provide a novel folding unit for folding and gluing opposite closing flaps of a head of boxes in a tubular configuration which is able to obviage the drawbacks referenced in the foregoing.

[0049] In particular, an aim of the invention is to provide a novel folding unit able to carry out, autonomously and completely, the folding and gluing of both opposite closing flaps present in the heads of the boxes in tubular configuration which are infed along an infeed direction.

[0050] The above-mentioned advantages are obtained according to the contents of the claims.

[0051] BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The characteristics of a preferred, but not exclusive, embodiment of the folding unit object of the present invention will be described in the following description with reference to the appended tables of drawings, in which:

[0053] - figure 1 , cited in the foregoing, illustrates, in a schematic perspective view, the advancement along an infeed direction of boxes in a tubular configuration having a first closing flap and a second closing flap at a respective open head, with the first closing flap hinged to a first upper face of the boxes and with the second closing flap hinged to a second lower face of the boxes, and the folding sequence of the first closing flap and of the second closing flap for closing a head of the boxes;

[0054] - figure 2, also cited in the foregoing, illustrates, in a schematic perspective view, the advancement along an infeed direction of boxes in a tubular configuration having a first closing flap and a second closing flap at a respective open head, with the first closing flap hinged to a first lower face of the boxes and with the second closing flap hinged to a second upper face of the boxes, and the folding sequence of the first closing flap and of the second closing flap for closing a head of the boxes;

[0055] - figure 3A illustrates, schematically and in a perspective view, the folding unit of the invention in a particular paused configuration before carrying out the folding of a first closing flap hinged to a first upper face of a box in tubular configuration which is advancing along an infeed direction towards a first stop position;

[0056] - figure 3B illustrates, schematically and in a perspective view, the folding unit of the invention in a particular operating step for folding the first closing flap hinged to a first upper face of a box in tubular configuration halted in a first stop position;

[0057] - figure 3C illustrates, schematically and in a perspective view, the folding unit of the invention arranged in a subsequent configuration and ready to start a following operating step for carrying out the folding of a second closing flap flap hinged to a second lower face of a box, with the first closing flap already folded, and which is positioned in a second stop position, subsequent to the first stop position;

[0058] - figure 3D illustrates, in a schematic perspective view, the folding unit of the invention in a particular operating step of completion of the folding of the second closing flap in which the second closing flap has been folded and arranged facing and in contact against the first closing flap, for the reciprocal gluing and closing of the head of the box;

[0059] - figure 4 illustrates, in a perspective exploded view, some significant components of the folding unit of the invention;

[0060] - figure 5 illustrates, in a section view according to a vertical section plane, other special components of the folding unit of the invention; figures 6A and 6B illustrate, according to respective schematic perspective views from different angles, a possible preferred embodiment of significant components of the folding unit of the invention designed to carry out the folding of a first closing flap present in a head of boxes in tubular configuration, and which are arranged and configured to carry out the folding of the first closing flap when the first closing flap is hinged to a first upper face of the boxes in tubular configuration; figures 7A and 7B illustrate, according to respective schematic perspective views from different angles, a possible preferred embodiment of further and other significant components of the folding unit of the invention designed to carry out the folding of a second closing flap present in a head of boxes in tubular configuration, and which are arranged and configured to carry out the folding of the second closing flap when the second closing flap is hinged to a second lower face of the boxes in a tubular configuration.

[0061] DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] With reference to the accompanying tables of drawings, reference numeral (100) denotes the folding unit for folding opposite closing flaps (L1, L2) of a head (A) of boxes (T) in a tubular configuration, object of the present invention, in its entirety.

[0063] In the boxes (A) in tubular configuration, the opposite closing flaps (L1 , L2) which are to be folded, for closing the head (A), comprise a first closing flap (L1), which is hinged to an end edge of a first face (F1) of the boxes (T), and a second closing flap (L2), which is hinged to an end edge of a second face (F2) of the boxes (T), opposite the first face (F1).

[0064] The boxes (A) in tubular configuration are fed along an infeed line (V) with the first face (F1) and the second face (F2) arranged substantially parallel to one another and parallel to the infeed line (V), and are time by time positioned, in succession, in a first stop position (S1), to enable folding the first closing flap (L1), and in a second stop position (S2), to enable folding the second closing flap (L2).

[0065] In this case too, as specified in the foregoing, the term first closing flap is taken to refer to the first of the two opposite flaps which is folded during the advancement of the boxes along the infeed line.

[0066] The folding unit (100) of the invention is positioned in an operating position (O) on a side of the infeed line (V), wherein the first closing flap (L1), and the second closing flap (L2) project, and substantially facing at the second stop position (S2) of the boxes (T) in tubular configuration along the infeed line (V).

[0067] The folding unit (100) comprises: a frame (9); glue application means (8); a drive shaft (10), activatable in rotation with respect to the frame (9) about a horizontal rotation axis (H), and transversal to the infeed line (V) of the boxes (T); a flat cam (1), coaxially mounted on the drive shaft (10) in such a way as to rotate about the horizontal rotation axis (H) when the drive shaft (10) is activated in rotation about the horizontal rotation axis (H), and comprising, on a respective face, a first annular channel (11) (see for example figure 4 and figures 6A, 6B); a drum cam (2), coaxially mounted on the drive shaft (10) in such a way as to rotate about the horizontal rotation axis (H) when the drive shaft (10) is activated in rotation about the horizontal rotation axis (H), and comprising, on the respective lateral surface, a second annular channel (21) (see for example figure 5 and figures 7A, 7B); a first folding element (3), which is borne by a first kinematism (31) connected by means of a first sliding element (32) to the first annular channel (11) of the flat cam (1), wherein the first sliding element (32) is conformed to slide internally of the first annular channel (11) following the driving in rotation of the flat cam (1) about the horizontal rotation axis (H); a second folding element (4), which is borne by a second kinematism (41) connected by means of a second sliding element (42) to the second annular channel (21) of the drum cam (2), wherein the second sliding element (42) is conformed to slide internally of the second annular channel (21) following the driving in rotation of the drum cam (2) about the horizontal rotation axis (H).

[0068] The first annular channel (11) is conformed in a respective pathway arranged on the face of the flat cam (1) and wherein the first kinematism (31) is configured in such a way that, when a box (T) is positioned in the first stop position (S1) and with the drive shaft (10) rotated in a first angular position (B1), the first sliding element (32) is positioned internally of the first annular channel (11) in such a way that the first folding element (3) is positioned in a respective moved-away starting position with respect to the first closing flap (L1) of the box (T) in the first stop position (S1) (see figure 3A).

[0069] The folding unit (100) is configured in such a way that: following a rotation of the drive shaft (10), about the horizontal rotation axis (H), from the first angular position (B1) (figure 3A) towards a second angular position (B2) (figure 3B) the following movements are carried out: the first sliding element (32), sliding internally of the first annular channel (11) during the rotation of the flat cam (1), causes the first folding element (3) to perform, by means of the first kinematism (31), a first vertical displacement towards the first closing flap (L1) during which the first folding element (3) intercepts the first closing flap (L1) and folds the first closing flap (L1), by rotating the first closing flap (L1) substantially by an angle of 90° with respect to the first face (F1) to which the first closing flap (L1) is hinged, in order to position the first closing flap (L1) in a first folding position in which the flap is arranged facing the head (A) of the box (T).

[0070] The glue application means (8) are arranged and configured, once the first closing flap (L1) has been folded into the first folding position, to be activatable to apply glue on the folded first closing flap (L1), or on the second closing flap (L2) still to be folded.

[0071] The second annular channel (21) is conformed according to a respective pathway on the lateral surface of the drum cam (2), and the second kinematism (41) is configured in such a way that, when the box (T) with the first closing flap (L1), folded, is advanced and positioned in the second stop position (S2) and with the drive shaft (10) rotated into a third angular position (B3), corresponding or successive to the second angular position (B2), the second sliding element (42) is positioned internally of the second annular channel (21) in such a way that the second folding element (4) is positioned in a respective starting position in which it is facing and moved away (figure 3B) with respect to the second closing flap (L2) of the box (T) in the second stop position (S2). The folding unit (100) is further configured in such a way that: following a successive rotation of the drive shaft (10), about the horizontal rotation axis (H), from the third angular position (B3) towards a fourth angular position (B4) (see figure 3D) the following movements are carried out: the second sliding element (42), sliding internally of the second annular channel (21) during the rotation of the drum cam (2), causes the second folding element (4) to perform, by means of the second kinematism (41), a first rotation towards the head (A) of the box (T) positioned in the second stop position (S2) during which the second folding element (4) intercepts the second closing flap (L2) and folds the second closing flap (L2), by rotating the second closing flap (L2) substantially by an angle of 90° with respect to the second face (F2) to which the second closing flap (L2) is hinged, in order to position the second closing flap (L2) in a second folding position in which the second closing flap (L2) is arranged facing the first closing flap (L1), for the reciprocal gluing and closing of the head (A) of the box (T).

[0072] Therefore, owing to the special conformation and configuration of the folding unit of the invention, which includes both the flat cam and the drum cam both mounted coaxially to a single and same drive shaft, and owing to the presence and particular conformation of the first annular channel, on a face of the flat cam, and of the second annular channel present on the lateral surface of the drum cam, with the rotation of the drive shaft it is possible to drive, by means of the first kinematism and the second kinematism, one following another, respectively the first folding element and the second folding element, and carry out the folding of initially the first closing flap and then the second closing flap.

[0073] Before carrying out the folding of the second closing flap, the glue application means are activatable to apply glue on the first closing flap, already folded, or on the second closing flap still to be folded, or possibly on both.

[0074] In this way, once also the second closing flap is folded against the first closing flap, it is possible to obtain the sealed closure of the head of the boxes by reciprocal gluing between the first and the second closing flap. Therefore, it will no longer be necessary, as occurred in the prior art, to use two distinct folding units, each for the folding of a respective closing flap.

[0075] Further, simply by regulating the angular position (timing) of the flat cam with respect to the first angular position of the drive shaft, and also the angular position (timing) of the drum cam, with the folding unit of the invention it is possible to carry out the folding of the first closing flap both when the first closing flap is hinged to a first upper face or to a first lower face of the boxes, and to carry out the folding of the second closing flap, both when the first closing flap is hinged to a second lower face or to a second upper face of the boxes.

[0076] Thus, with the folding unit of the invention, it is possible to carry out the folding sequence illustrated in figure 1 , wherein the first closing flap (L1) is hinged to a first upper face (F1) of the boxes (T) and the second closing flap (L2) is hinged to a second lower face (F2) of the boxes (T), as well the folding sequence illustrated in figure 2, wherein the first closing flap (L1) is hinged to a first lower face (F1) of the boxes (T) and the second closing flap (L2) is hinged to a second upper face (F2) thereof.

[0077] Therefore, with the folding unit of the invention, each time there is a size change and / or and change of the type of conformation of the boxes, and a different positioning of the first and second closing flap, with respect to the upper and lower faces of the boxes, by simply regulating the timing of the flat cam and the drum cam, with respect to the drive shaft, as well as other simple regulation of components, as will be further described in detail in the following, it will be possible to proceed with the folding operations without performing any other complicated regulating or demounting and remounting of the two folding units of the boxes, as was required in the prior art.

[0078] Further and other aspects of the folding unit of the invention are described in the following.

[0079] The first annular channel (11) and the second annular channel (21) are conformed according to respective pathways and reciprocally arranged on the face of the flat cam (1) and on the lateral surface of the drum cam (2), and the first kinematism (31) and the second kinematism (41) are configured in such a way that, with the completion of a complete rotation of the rotation shaft (10) about the horizontal rotation axis (H), from the fourth angular position (B4) newly into the first angular position (B1), and then, with a complete rotation of the flat cam (1) and a complete rotation of the drum cam (2), the following further movements are carried out: the first sliding element (32), sliding internally of the first annular channel (11) during the rotation of the flat cam (1), causes the first folding element (3) to perform, by means of the first kinematism (31), a second vertical displacement in a moving away direction from the head (A) of the box (T), returning the first folding element (3) into the respective moved-away starting position (figure 3A); the second sliding element (42), sliding internally of the second annular channel (21) during the rotation of the drum cam (2), causes the second folding element (4) to perform, by means of the second kinematism (42), a second rotation in a moving away direction from the head (A) of the box (T), returning the second folding element (4) into the respective moved-away starting position (figures 3B and 3C).

[0080] According to the preferred but not exclusive embodiment illustrated in the figures, the first kinematism (31) can be made in such a way as to comprise (see for example figures 6A, 6B): a first lever (310) which is rotatably constrained, on a first side, to a portion of the frame (9) of the folding unit (100) about a first rotation axis (V1) parallel to the horizontal rotation axis (H) of the drive shaft (10) and which is connected to the first sliding element (32), and a second lever (311) which is rotatably constrained, at a respective first side, to a portion of the frame (9) of the folding unit (100) about a second rotation axis (V2) parallel to the first rotation axis (V1) and to the horizontal rotation axis (H) of the drive shaft (10), wherein the first lever (310) and the second lever (311) are rotatably connected, at a respective second side thereof, to a support plate (315) of an upright element (312) which bears the first folding element (3). In particular, the plate (315) is dimensioned and the upright element (312) is mounted on the plate (315) in such a way that the first folding element (3) is arranged facing the first stop position (S1) in which the boxes (T) are time by time positioned during the advancement thereof along the infeed line (V).

[0081] In a further advantageous aspect, the upright element (312) comprises, longitudinally, a slot (313) which enables the connection of the upright element (312) to the plate (315) in different working positions, in such a way as to vary and regulate the position of the first folding element (3) with respect to the position of the first closing flap (L1) when the box (T) is positioned in the first stop position (S1).

[0082] For example, in figures 6A and 6B, the upright element (312) which bears the first folding element (3), is connected to the first lever (310) and to the second lever (311) in a first working position (W1).

[0083] The arrangement of the upright element (312) in the first working position (W1), together with the regulation of the timing of the flat cam (1) with respect to the drive shaft (10), enables using the folding unit (100) of the invention to carry out the folding of the first closing flap (L1) when the first closing flap (L1) is hinged to an end edge of a first upper face (F1) of the boxes in tubular configuration (sequence of figure 1), as the first folding element (3) is moved from above in a downwards direction during the rotation of the drive shaft (10) from the first angular position (B1) to the second angular position (B2), thus folding the first closing flap (L1) downwards.

[0084] By varying the arrangement and position of the upright element (312) with respect to the plate (315), for example by arranging it in a lower position with respect to the position illustrated in figures 6A and 6B, the upright element (312), which bears the first folding element (3), can therefore be positionable in a second working position with respect to the plate (315), in which the first folding element (3) will be at a lower height with respect to the infeed line of the boxes.

[0085] The arrangement of the upright element (312) in the second working position, together with the regulation of the timing of the flat cam (1) with respect to the drive shaft (10), enables using the folding unit (100) of the invention to carry out the folding of the first closing flap when the first closing flap is hinged to a first lower face of the boxes in tubular configuration (sequence of figure 2).

[0086] In this case, the first folding element (3) is moved from below in an upwards direction during the rotation of the drive shaft (10) from the first angular position (B1) to the second angular position (B2), thus folding the first closing flap (L1) upwards.

[0087] Further, owing to the presence of the slot along the upright element, it is possible to regulate the position (height) of the first folding element between a minimum height and a maximum height, with respect to the infeed line of the boxes, which enables carrying out the folding of the first closing flap when changing size (dimensions) of the boxes, without having to carry out the demounting and remounting of the folding unit in different positions.

[0088] According to the preferred but not exclusive embodiment illustrated in the figures, see in particular figures 7A and 7B, the second kinematism (41) can be made in such a way as to comprise: a third lever (410) which is connected to the second sliding element (42), a fourth lever (411) which is rotatably constrained to a portion of the frame (9) of the folding unit (100) about a fourth rotation axis (V4) perpendicular to a vertical plane containing the horizontal rotation axis (H) of the drive shaft (10), a fifth lever (412) hinged, on a first side, to the third lever (410) and, at a second side, to the fourth lever (411), a sixth lever (413) which is hinged, at a respective first side, to the fourth lever (411) coaxially to the fourth rotation axis (V4), an arm (414) which is hinged, at a first end, to a second side of the sixth lever (413) and which is hinged, at a second end, to a crank element (415) which is rotatably hinged to a fifth rotation axis (V5) parallel to the infeed line (V) and transversal to the rotation shaft (H) of the drive shaft (10), with the second folding element (4) being rigidly connected to the crank element (415) in such a way as to be activatable in rotation about the fifth rotation axis (V5).

[0089] Figures 7A and 7B illustrate a situation in which the second kinematism (41) is configured with the above-described components it is composed of so as to carry out the folding of the second closing flap when the second closing flap is hinged to a second lower face of the boxes, therefore in such a way as to cause the second folding element, conformed for example in the shape of a paddle, to make a first rotation upwards with respect to the fifth hinge axis, in order to fold the second closing flap upwards.

[0090] By replacing the arm (414) with another arm of a greater length, and hinging the crank element (415) to a fifth rotation axis (V5) arranged in an upper position, and varying the timing of the drum cam with respect to the drive shaft, it is possible to cause the second folding element to perform a first rotation in a downwards direction, and therefore to fold the second closing flap downwards when the second closing flap is hinged to a second upper face of the boxes.

[0091] Time by time, and simply by using an arm of an adequate length, varying the position of the fifth hinge axis of the crank element, and the timing of the drum cam, it will be possible to adjust the folding unit to the particular dimensions, i.e. to the size, of the tubular boxes, and to the position of the second closing flap, without having to carry out any demounting and remounting of the folding unit into different positions with respect to the infeed direction of the boxes.

[0092] In a further preferred aspect of the folding unit of the invention, the glue application means (8) comprise at least a glue dispenser element (81) borne by a vertical support element (82) mounted on a portion of the frame (9).

[0093] On the basis of a further and other aspect, the folding unit of the invention can preferably comprise an abutment element (88) which is arranged parallel to the infeed line (V) and transversally to the horizontal rotation axis (H) of the drive shaft (10).

[0094] The abutment element (88) is positioned between the first stop position (S1) and the second stop position (S2) and is configured to abut and maintain the first closing flap (L1) folded in the first folding position, in which it is facing the head (A) of the boxes (T), during the advancement of the boxes (T) from the first stop position (S1) to the second stop position (S2).

Claims

CLAIMS1) A folding unit (100) for folding opposite closing flaps (L1, L2) of a head (A) of boxes (A) in tubular configuration, wherein the closing flaps (L1, L2) comprise a first closing flap (L1), which is hinged to an end edge of a first face (F1) of the boxes (T), and a second closing flap (L2), which is hinged to an end edge of a second face (F2) of the boxes (T), opposite the first face (F1), wherein the boxes (A) in tubular configuration are fed along an infeed line (V) with the first face (F1) and the second face (F2) arranged substantially parallel to one another and parallel to the infeed line (V), and are time by time positioned, in succession, in a first stop position (S1), to enable folding the first closing flap (L1), and in a second stop position (S2), to enable folding the second closing flap (L2), wherein the folding unit (100) is positioned in an operating position (O) on a side of the infeed line (V), wherein the first closing flap (L1), and the second closing flap (L2) project, and substantially facing at the second stop position (S2) of the boxes (T) in tubular configuration along the infeed line (V), wherein the folding unit (100) comprises: a frame (9); glue application means (8); a drive shaft (10), activatable in rotation with respect to the frame (9) about a horizontal rotation axis (H), and transversal to the infeed line (V) of the boxes (T); a flat cam (1), coaxially mounted on the drive shaft (10) in such a way as to rotate about the horizontal rotation axis (H) when the drive shaft (10) is activated in rotation about the horizontal rotation axis (H), and comprising, on a respective face, a first annular channel (11); a drum cam (2), coaxially mounted on the drive shaft (10) in such a way as to rotate about the horizontal rotation axis (H) when the drive shaft (10) is activated in rotation about the horizontal rotation axis (H), and comprising, on the respective lateral surface, a second annular channel (21),a first folding element (3), which is borne by a first kinematism (31) connected by means of a first sliding element (32) to the first annular channel (11) of the flat cam (1), wherein the first sliding element (32) is conformed to slide internally of the first annular channel (11) following the driving in rotation of the flat cam (1) about the horizontal rotation axis (H); a second folding element (4), which is borne by a second kinematism (41) connected by means of a second sliding element (42) to the second annular channel (21) of the drum cam (2), wherein the second sliding element (42) is conformed to slide internally of the second annular channel (21) following the driving in rotation of the drum cam (2) about the horizontal rotation axis (H); wherein the first annular channel (11) is conformed in a respective pathway arranged on the face of the flat cam (1) and wherein the first kinematism (31) is configured in such a way that, when a box (T) is positioned in the first stop position (S1) and with the drive shaft (10) rotated in a first angular position (B1), the first sliding element (32) is positioned internally of the first annular channel (11) in such a way that the first folding element (3) is positioned in a respective moved-away starting position with respect to the first closing flap (L1) of the box (T) in the first stop position (S1), and wherein, following a rotation of the drive shaft (10), about the horizontal rotation axis (H), from the first angular position (B1) towards a second angular position (B2) the following movements are carried out: the first sliding element (32), sliding internally of the first annular channel (11) during the rotation of the flat cam (1), causes the first folding element (3) to perform, by means of the first kinematism (31), a first vertical displacement towards the first closing flap (L1) during which the first folding element (3) intercepts the first closing flap (L1) and folds the first closing flap (L1), by rotating the first closing flap (L1) substantially by an angle of 90° with respect to the first face (F1) to which the first closing flap (L1) is hinged, in order to position the first closing flap (L1) in a first folding position in which the flap is arranged facing the head (A) of the box (T); wherein the glue application means (8), once the first closing flap (L1) hasbeen folded into the first folding position, are activatable to apply glue on the folded first closing flap (L1), or on the second closing flap (L2) still to be folded; wherein the second annular channel (21) is conformed according to a respective pathway on the lateral surface of the drum cam (2), and wherein the second kinematism (41) is configured in such a way that, when the box (T) with the first closing flap (L1) folded is advanced and positioned in the second stop position (S2) and with the drive shaft (10) rotated into a third angular position (B3), corresponding or successive to the second angular position (B2), the second sliding element (42) is positioned internally of the second annular channel (21) in such a way that the second folding element (4) is positioned in a respective starting position in which it is facing and moved away with respect to the second closing flap (L2) of the box (T) in the second stop position (S2), and wherein following a successive rotation of the drive shaft (10), about the horizontal rotation axis (H), from the third angular position (B3) towards a fourth angular position (B4) the following movements are carried out: the second sliding element (42), sliding internally of the second annular channel (21) during the rotation of the drum cam (2), causes the second folding element (4) to perform, by means of the second kinematism (41), a first rotation towards the head (A) of the box (T) positioned in the second stop position (S2) during which the second folding element (4) intercepts the second closing flap (L2) and folds the second closing flap (L2), by rotating the second closing flap (L2) substantially by an angle of 90° with respect to the second face (F2) to which the second closing flap (L2) is hinged, in order to position the second closing flap (L2) in a second folding position in which the second closing flap (L2) is arranged facing the first closing flap (L1), for the reciprocal gluing and closing of the head (A) of the box (T).2) The folding unit (100) as claimed in claim 1 , wherein the first annular channel (11) and the second annular channel (21) are conformed according to respective pathways and reciprocally arranged on the face of the flat cam (1)and on the lateral surface of the drum cam (2), and wherein the first kinematism (31) and the second kinematism (41) are configured in such a way that, with the completion of a complete rotation of the rotation shaft (10) about the horizontal rotation axis (H), from the fourth angular position (B4) newly into the first angular position (B1), and then, with a complete rotation of the flat cam (1) and a complete rotation of the drum cam (2), the following further movements are carried out: the first sliding element (32), sliding internally of the first annular channel (11) during the driving in rotation of the flat cam (1), causes the first folding element (3) to perform, by means of the first kinematism (31), a second vertical displacement in a moving away direction from the head (A) of the box (T), returning the first folding element (3) into the respective moved-away starting position; the second sliding element (42), sliding internally of the second annular channel (21) during the rotation of the drum cam (2), causes the second folding element (4) to perform, by means of the second kinematism (42), a second rotation in a moving away direction from the head (A) of the box (T), returning the second folding element (4) into the respective moved-away starting position.3) The folding unit (100) as claimed in any one of claims 1 and 2, wherein the first kinematism (31) comprises a first lever (310) which is rotatably constrained, on a first side, to a portion of the frame (9) of the folding unit (100) about a first rotation axis (V1) parallel to the horizontal rotation axis (H) of the drive shaft (10) and which is connected to the first sliding element (32), and a second lever (311) which is rotatably constrained, at a respective first side, to a portion of the frame (9) of the folding unit (100) about a second rotation axis (V2) parallel to the first rotation axis (V1) and to the horizontal rotation axis (H) of the drive shaft (10), wherein the first lever (310) and the second lever (311) are rotatably connected, at a respective second side thereof, to a support plate (315) of an upright element (312) which bears the first folding element (3), wherein the plate (315) is dimensioned and wherein the upright element (312) is mounted on the plate (315) in such a way that thefirst folding element (3) is arranged facing the first stop position (S1) in which the boxes (T) are time by time positioned during the advancement thereof along the infeed line (V).4) The folding unit (100) as claimed in claim 3, wherein the upright element (312) comprises, longitudinally, a slot (313) which enables the connection of the upright element (312) to the plate (315) in different working positions, in such a way as to vary and regulate the position of the first folding element (3) with respect to the position of the first closing flap (L1) when the box (T) is positioned in the first stop position (S1).5) The folding unit (100) as claimed in any one of claims from 2 to 4, wherein the second kinematism (41) comprises a third lever (410) which is connected to the second sliding element (42), a fourth lever (411) which is rotatably constrained to a portion of the frame (9) of the folding unit (100) about a fourth rotation axis (V4) perpendicular to a vertical plane containing the horizontal rotation axis (H) of the drive shaft (10), a fifth lever (412) hinged, on a first side, to the third lever (410) and, at a second side, to the fourth lever (411), a sixth lever (413) which is hinged, at a respective first side, to the fourth lever (411) coaxially to the fourth rotation axis (V4), an arm (414) which is hinged, at a first end, to a second side of the sixth lever (413) and which is hinged, at a second end, to a crank element (415) which is rotatably hinged to a fifth rotation axis (V5) parallel to the infeed line (V) and transversal to the rotation shaft (H) of the drive shaft (10), wherein the second folding element (4) is rigidly connected to the crank element (415) in such a way as to be activatable in rotation about the fifth rotation axis (V5).6) The folding unit (100) as claimed in any one of claims from 1 to 5, wherein the glue application means (8) comprise at least a glue dispenser element (81) borne by a vertical support element (82) mounted on a portion of the frame (9).7) The folding unit (100) as claimed in any one of claims from 1 to 6, comprising an abutment element (88) arranged parallel to the infeed line (V) and transversally to the horizontal rotation axis (H) of the drive shaft (10), theabutment element (88) being positioned between the first stop position (S1) and the second stop position (S2) and being configured to abut and maintain the first closing flap (L1) folded in the first folding position in which it is arranged facing the head (A) of the boxes (T), during the advancement of the boxes (T) from the first stop position (S1) to the second stop position (S2).

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