A machine for packing articles internally of respective envelopes starting from a sheet made of paper material

Abstract

The machine (M) folds a sheet (P) of paper material about articles to obtain a tube of sheet (TB) containing internally thereof the articles. The machine (M) comprises compression and cutting means (7), for compressing and cutting the tube of sheet (TB) transversally, anteriorly and posteriorly of the articles contained therein, in order to obtain envelopes containing, internally thereof, respective articles. The machine (M) comprises first application means (20) of adhesive material for applying transversal strips (S) of adhesive material on the central part (PC) of the sheet (P), between which the articles are to be placed, with the first application means (20) of adhesive material also being actionable, when the articles have a width that is smaller than the width of the central part (PC) of the sheet (P), to apply a longitudinal strip (L) of adhesive material on the central part (PC) of the sheet (P) at a distance from a first edge (PC1) of reference of the central part (PC) that is at least equal to the width of the article. The machine comprises (M) a supplementary compression and cutting unit (71) for compressing and cutting the tube of sheet (TB) longitudinally at the longitudinal strip (L) of adhesive material so as to obtain an envelope having a width that substantially corresponds to that of the article packaged therein.

Description

[0001] A MACHINE FOR PACKING ARTICLES INTERNALLY OF RESPECTIVE ENVELOPES STARTING FROM A SHEET MADE OF PAPER MATERIAL

[0002] DESCRIPTION OF THE INVENTION

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to the technical sector concerning the packaging of articles internally of respective envelopes starting from a sheet made of paper material, in particular a sheet made of a multilayer paper material, for example a sheet formed by at least a layer of paper for packaging and by a goffered layer of paper glued to the layer of paper for packaging.

[0005] In particular, the present invention relates to a machine for packing articles in envelopes, following the wrapping of a sheet of multilayer paper material about articles advancing along an advancement direction, and for forming closed envelopes containing single articles.

[0006] DESCRIPTION OF THE PRIOR ART

[0007] A known machine for packaging articles by internally of respective envelopes starting from a sheet made of a paper material is described in Italian patent no. 102020000012661.

[0008] In the machine for packaging described in this document, the articles to be packed are advanced one following another by conveyor means while the sheet made of paper material is unwound from a relative reel and, via feeding means, is supplied to the end of the conveyor means and transversally to the advancement direction of the articles.

[0009] Relay means are present for arranging the sheet made of paper material in such a way that a central part of the sheet made of paper material is brought into contact with an aspirated conveyor belt, arranged consecutively to the conveyor means of the articles, and in such a way that lateral parts of the sheet made of paper material remain in lateral projection from the conveyor belt.

[0010] First application means of adhesive material are present, for applying transversal strips of adhesive material on the central part of the sheet made of paper material destined to be in contact with, and retained by, the aspirated conveyor belt, in which the portions of the central part of the sheet made of paper material comprised between two consecutive transversal strips of adhesive material are destined to restingly receive the a respective article which is to be packed internally of a respective envelope.

[0011] In this regard, the machine comprises detection means for detecting the dimensions of the articles, in particular of the base face thereof, in such a way as to determine the extension thereof, i.e. the length, in the direction of the advancement direction, in such a way that the first application means of adhesive material can be activated to apply the transversal strips of adhesive material moved away from one another by a distance that is at least greater than the length of the base face of the articles which are to packed in a respective envelope.

[0012] The articles are advanced by the conveyor means so as to convey them above the central part of the sheet made of paper material, arranged above the aspirated conveyor belt, with each of the articles being arranged between two consecutive respective transversal strips of adhesive material.

[0013] The aspirated conveyor belt then moves the sheet made of paper material, with the articles arranged on the relative central part, retaining the sheet made of paper material by aspiration, thus moving both the sheet made of paper material and the articles arranged thereon, according to a transport direction.

[0014] The machine for packaging further comprises a structure conformed as a tunnel which is associated to the aspirated conveyor belt and which is dimensioned and conformed to allow passage internally thereof of the articles transported by the conveyor belt above the central part of the sheet made of paper material, and folder means which are configured and conformed to abut the lateral parts of the sheet made of paper material, projecting laterally from the aspirated conveyor belt, in order to fold them about the structure conformed as a tunnel in such a way as to mutually superpose the two lateral flaps of the sheet made of paper material to form a tube of sheet wound about the structure conformed as a tunnel. Second application means of adhesive material are present superiorly of the structure conformed as a tunnel for applying adhesive material on one of the two flaps of the sheet made of paper material before superposing the flaps, and, downstream of the structure conformed as a tunnel, compression and cutting means are present, located at an interruption of the aspirated conveyor belt, configured and activatable to clamp the tube of sheet, at the front and end of each single article present internally of the tube of sheet, at the position of the transversal strips of adhesive material, in order to realise the closing and cutting of the tube of sheet so as to obtain single envelopes with respective single articles internal thereof.

[0015] A packaging machine of this type, while efficient in the wrapping operations of single articles internally of respective envelopes, does however have a drawback.

[0016] In fact, independently of the effective dimensions of the articles to be packed, in particular the width thereof, i.e. for the extension thereof in a transversal direction with respect to the advancement direction of the central part of the sheet made of paper material arranged and retained by aspiration of the aspirated conveyor belt, the envelopes which are obtained always and in any case have a same predetermined width, which corresponds to the width (transversal extension) of the central part of the sheet made of paper material.

[0017] Thus, in a case in which the articles to be packed have a width (transversal extension with respect to the advancement direction) that is smaller than the width (transversal extension) of the central part of the sheet made of paper material, for example by half, or even a third, then the envelopes that will be obtained will be over-sized with respect to the articles packed internally thereof, which therefore, during the transport of the envelopes, may be free to move internally of the envelopes, with consequent impacts or blows to the paper material constituting the envelopes, which can therefore be damaged.

[0018] Further, the envelopes might more easily deteriorate and deform during the transport thereof. SUMMARY OF THE INVENTION

[0019] The aim of the present invention is therefore to provide a novel wrapping machine for packaging articles internally of respective envelopes obtained starting from a sheet made of paper material able to obviate the above- mentioned drawbacks.

[0020] In particular, an aim of the present invention is to describe a novel machine able to realise the appropriately-dimensioned envelopes in relation to the effective dimensions, in terms of width, of the articles to be packaged.

[0021] The above aims are attained by a machine for packing articles internally of respective envelopes starting from a sheet made of paper material, in particular, a multilayer paper material according to the contents of the claims.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] A preferred embodiment of the machine for packing articles internally of respective envelopes starting from a sheet made of paper material, in particular multilayer paper material, is described in the following with reference to the accompanying tables of drawings, in which:

[0024] - figure 1 is a schematic perspective view of the machine of the present invention;

[0025] - figure 2 is a schematic illustration of the steps of the wrapping of the sheet made of paper material about the articles and the obtaining of the envelopes containing single articles carried out by the machine of the invention;

[0026] - figure 3 illustrates detail K of figure 1 in larger scale;

[0027] - figure 4 illustrates, in a perspective view, some significant components of the machine of figure 1;

[0028] - figure 5 is a schematic perspective view of the initial step of the wrapping of the sheet made of paper material about an article in advancement;

[0029] - figure 6 schematically illustrates some components of the machine responsible for application of adhesive material on the flaps of sheet made of paper material which are superposed on one another for formation of the tube of sheet;

[0030] - figure 7 is a schematic partial perspective view of other special components of the machine of the invention;

[0031] - figure 8 is a partial perspective view of other details of the machine of the invention;

[0032] - figure 9 illustrates, in a schematic perspective view, the components of the machine of the invention responsible for the cutting of the tube of sheet for the formation of single envelopes containing respective single articles;

[0033] - figure 10 illustrates, in a partial perspective view, the components of the machine responsible for application of adhesive material on the central part of the sheet made of paper material destined to rest on, and to be retained by aspiration by, the aspirated conveyor belt;

[0034] - figures 11 and 12 schematically illustrate the cutting steps of the tube of sheet for obtaining a first envelope, containing a respective article, and having a first width;

[0035] - figures 13 and 14 schematically illustrate the cutting steps of the tube of sheet for obtaining a second envelope, containing a respective article, and having a second width;

[0036] - figures 15 and 16 schematically illustrate the cutting steps of the tube of sheet for obtaining a third envelope, containing a respective article, and having a third width.

[0037] DESCRIPTION OF PREFERRED EMBODIMENTS

[0038] With reference to the accompanying tables of drawings, reference letter (M) denotes the machine (M) for wrapping a sheet (P) made of paper material (P), in particular a sheet (P) made of a multilayer paper material about articles (A) for forming envelopes (B) containing single articles, proposed by the present invention, in its entirety.

[0039] The machine (M) comprises: conveyor means (1), which are configured for receiving and conveying articles (A) which are to be wound about by a sheet (P) made of paper material according to a conveying direction (D); an aspirated conveyor belt (2), which is arranged consecutively to the conveyor means (1); a supply station (3) of a sheet (P) made of paper material (P), comprising a reel (30) on which a sheet (P) made of paper material is wound and supply and relay means (31) for feeding the sheet (P) made of paper material between the conveyor means (1) and the conveyor belt (2), transversally to the conveying direction (D) of the articles (A), and for arranging the sheet (P) made of paper material with a relative central part (PC) resting on the aspirated conveyor belt (2) and with lateral parts (PL1 , PL2) in relation to the central part (PC) laterally projecting from the aspirated conveyor belt (2), so that the articles (A) conveyed by the conveyor means (1) become arranged above the central part (PC) of the sheet (P) made of paper material arranged resting on the aspirated conveyor belt (2) and so that the sheet (P) made of paper material with the articles (A) arranged on the relative central part (PC) can be retained by aspiration by the aspirated conveyor belt (2) and advanced in a transport direction (E); folder means (4), arranged and configured with respect to the aspirated conveyor belt (2) so as to be able to abut and fold the lateral parts (PL1 , PL2) of the sheet (P) made of paper material that are laterally projecting from the aspirated conveyor belt (2).

[0040] The machine (M) further comprises: a structure (5) associated to the aspirated conveyor belt (2) and which is conformed in such a way as to define a tunnel (T) for passage of the articles (A) transported by the aspirated conveyor belt (2) above the central part (PC) of the sheet (P) made of paper material, with the folder means (4) being arranged with respect to the conveyor belt (2), and with respect to the structure (5) conformed as a tunnel (T), and being conformed and configured in such a way as to abut the lateral parts (PL1 , PL2) of the sheet (P) made of paper material laterally projecting from the aspirated conveyor belt (2), during advancement thereof, and to fold the lateral parts (PL1, PL2) about the structure (5) conformed as a tunnel (T) in such a way as to superpose the two lateral flaps (L1, L2) of the sheet (P) made of paper material and form a tube of sheet (TB) which is wound about the structure (5) conformed as a tunnel (T).

[0041] In particular, the structure (5) conformed as a tunnel (T) is made in such a way that the tunnel (T) defines a passage space for passage of the articles (A) having a height with respect to the conveyor belt (2) that is such that internally thereof articles (A) can be conveyed that have different dimensions and heights, for example single magazines, books, stacked magazines associate to one another, boxes containing products, and so on.

[0042] In this way, with a single frame and a single configuration of the wrapping machine (M) (structure conformed as a tunnel, folder means) it is possible to wrap a sheet (P) made of paper material about articles of different heights advancing along the conveyor belt.

[0043] The wrapping machine (M) further comprises: first application means (20) of adhesive material, which are arranged in an area between the conveyor means (1) and the aspirated conveyor belt (2) and which are configured to apply transversal strips (S) of adhesive material on the portion of the sheet (P) made of paper material, which will then be arranged above the aspirated conveyor belt (2) going to form the central part (PC) of the sheet (P) made of paper material which is retained by aspiration by the aspirated conveyor belt (2) (see for example figure 10).

[0044] In particular, the first application means (20) of adhesive material are actionable to apply transversal strips (S) of adhesive material which are reciprocally moved away from one another on the basis of the length of the articles (A), in the longitudinal direction of the central part (PC) of the sheet (P), i.e. in the transport direction (E) thereof, which are to be packaged.

[0045] For example, the first application means (20) of adhesive material can comprise a plurality of dispensing heads or nozzles of adhesive material, arranged flanked to one another, and transversally to the transport direction (E) of the sheet (P) made of paper material.

[0046] The machine further comprises second application means (6) of adhesive material, which are positioned above the structure (5) conformed as a tunnel (T) and which are configured to apply adhesive material on at least one of the two flaps (L1, L2) of the sheet made of paper material (P) before the superposing thereof to form the tube of sheet (TB); and compression and cutting means (7), which are positioned downstream of the structure (5) conformed as a tunnel (T), at an interruption of the aspirated conveyor belt (2), and which are activatable to transversally clamp the tube of sheet (TB), first anteriorly and then posteriorly with respect to the position of an article (A) in the tube of sheet (TB), at respective two transversal strips (S) of adhesive material between which the article (A) has been positioned, so as to realise the closing and cutting of the tube of sheet (P) and obtain an envelope (B) containing the article (A) internally thereof.

[0047] The machine (M) has a detecting station (80) which is arranged along the conveyor means (1).

[0048] The detecting station (80) comprises detection means (85) which are arranged and configured in such a way as to detect the dimensions of the articles (A) passing through the detecting station (80), in particular for detecting the width of the articles (A), i.e. the extension thereof in a transversal direction with respect to the conveying direction (D) thereof towards the aspirated conveyor belt (2).

[0049] The machine (M) is thus configured in such a way that the first application means (20) of adhesive material, on the basis of the data supplied by the detection means (85) in relation to the width detected of the articles (A) which are advancing along the conveying direction (D) towards the aspirated conveyor belt (2), are also actionable, should the width detected for a given article be lower than a predetermined width corresponding to a maximum width for an article to be packaged, substantially equal to the width of the central part (PC) of the sheet (P) of paper material: to apply two respective transversal strips (S) of adhesive material, distanced from one another by a distance that is at least equal to the length of the article to be packaged and having an extension, starting from a first edge (PC1) of the central part (PC) of the sheet (P) of paper material, at least equal to the width detected for the given article, and to apply at least a longitudinal strip (L) of adhesive material, longitudinally on a portion of the central part (PC) of the sheet (P) of paper material, and transversally to the two respective transversal strips (S) of adhesive material, at a distance from the first edge (PC1) of the central part (PC) of the sheet (P) at least equal to the width detected for the article to be packaged.

[0050] In this way, on the central part (PC) of the sheet (P) of paper material, the two respective transversal strips (S) of adhesive material and the longitudinal strip (L) of adhesive material form a sort of border of adhesive material in a II- shape, defining internally thereof an area for positioning the article to be packaged.

[0051] In this regard, see for example figure 10, in which a first article (A1) is illustrated arranged above the central part (PC) of the sheet (P) of paper material which has a width that is substantially equal to, or slightly smaller than, the predetermined width, and thus substantially corresponding to the width of the central part (PC) of the sheet (P) made of paper material arranged on, and retained by means of aspiration by, the aspirated conveyor belt (2).

[0052] In this case, the first application means (20) of adhesive material will be activated to apply on the central portion (PC) of the sheet (P) made of paper material only two respective transversal strips (S) of adhesive material distanced from one another by a distance that is at least equal to the length of the first article (A1), in a longitudinal direction with respect to the central portion (PC), i.e. in the transport direction (E).

[0053] On the other hand, again with reference to figure 10, a second article (A2) is also illustrated, which instead has a width that is smaller than the predetermined width, and therefore, in this case, the first application means (20) of adhesive material are activatable to apply, as well as the transversal strips (S) of adhesive material distanced from one another by a distance that is at least equal to the length of the second article (A2), also at least a longitudinal strip (L) of adhesive material, longitudinally on a portion of the central part (PC) of the sheet made of paper material (P) and between the respective transversal strips (S) of adhesive material, in which the longitudinal strip (L) of adhesive material is applied on the central part (PC) at a distance from the first edge (PC1) of reference of the central part (PC) that is at least equal to the width of the second article (A2), detected by the detection means (85).

[0054] In this way, the transversal strips (S) and the longitudinal strip (L) of adhesive material applied on the central part (PC) of the sheet (P), will surround the second article (A2) once the second article (A2) has been transferred onto the central part (PC) of the sheet (P), in order to be wrapped inside the tube of sheet (TB).

[0055] Further, the machine (M) is made in such a way that the compression and cutting means (7) comprise at least a supplementary compression and cutting unit (71) which is configured, consequently to the application of the at least a longitudinal strip (L) of adhesive material on a portion of the central part (PC) of the sheet made of paper material when the detection means (85) detect that an article (A) has a width that is smaller than the predetermined width, in order to be activatable in such a way as to longitudinally compress the tube of sheet (TB) at the position of the longitudinal strip (L) of adhesive material and in order to longitudinally cut the tube of sheet (TB) parallel to the longitudinal strip (L) of adhesive material in order to obtain an envelope (B1 , B2, B3) having a width substantially corresponding to the article packed therein, and to reject a strip (SR) of tube of sheet (TB) that is excessive beyond the width of the article.

[0056] In this regard, see figures from 11 to 16, in which three different situations are illustrated wherein the three envelopes (B1 , B2, B3) obtained have a different width, commensurate with the width of the articles packaged therein.

[0057] For example, figures 11 and 12 illustrate a case of packaging an article having a width that is substantially corresponding to the width of the central part (PC) of the sheet (P) of paper material, and therefore the supplementary compression and cutting unit (71) remains inactive, as the detection means (85) will have detected a width for the article to be packaged that substantially corresponds to the predetermined width; the envelope (B1) will then be obtained following the single transversal cut of the tube of sheet (TB) by the compression and cutting means (7).

[0058] Figures 13 and 14 and figures 15 and 16, on the other hand, respectively illustrate two cases in which the articles to be packaged present relative widths that are smaller than the predetermined width, and therefore the supplementary compression and cutting unit (71) is activated and actioned to carry out the longitudinal cut of the tube of sheet (TB) so as to obtain two respective envelopes (B2, B3) having different widths, commensurate with the width of the articles packaged therein.

[0059] Therefore, owing to the above-described characteristics, with the machine of the invention it is possible to obtain perfectly dimensioned envelopes that are commensurate with the effective dimensions of the packaged articles, in particular envelopes having a width that is substantially corresponding to the width of the articles, thus obviating the drawback present in the wrapping machines of known type mentioned in the foregoing.

[0060] Other advantageous characteristics and aspects of the machine (M) of the invention are set out in the following.

[0061] The compression and cutting means (7), with the aim of transversally clamping the tube of sheet (TB), at respective transversal strips (S) of adhesive material and cutting the tube of sheet and obtaining the envelopes, comprise at least a pair of bars (70) arranged transversally, and bilaterally, to the tube of sheet (TB), and provided with a cutting blade.

[0062] The bars (70) are actionable towards and away from one another in such a way as to clamp the tube of sheet (TB), first frontally and then posteriorly, with respect to the position of an article (A) in the tube of sheet (TB), at respective two transversal strips (S) of adhesive material between which the article (A) has been positioned, in order to compress the portions of the tube of sheet where the adhesive material is present, realising the closure thereof by mutual adhesion, and then, with the cutting blade, contemporaneously cutting the tube of sheet (TB) in order to obtain an envelope (B) containing the article (A) internally thereof.

[0063] The above-mentioned supplementary compression and cutting unit (71) comprises at least a movable unit (72) which is mounted slidingly along a first guide (730), arranged superiorly and transversally with respect to the tube of sheet (TB), and which is also translatable vertically downwards and thus against the tube of sheet (TB).

[0064] The movable unit (72) comprises at least a first compression element (73) (for example a rubberised wheel) and a first cutting element (74) (for example a pneumatically-oscillating blade), which are arranged and configured in such a way as to compress the tube of sheet (TB) and cut the tube of sheet (TB) longitudinally, once the movable unit (72) is translated downwards against the tube of sheet (TB), and consequently to the advancement of the tube of sheet (TB) carried out by the aspirated conveyor belt (4).

[0065] In particular, the movable unit (72), on the basis of the width of the articles detected by the detection means (85), is translated along the first guide (730) so as to be positioned in a position with respect to the tube of sheet (TB) corresponding to the position in which the longitudinal strip (L) of adhesive material has been applied on the central part (PC) of the sheet (P) of paper material.

[0066] Thus, when the tube of sheet (TB) with the article (A) internal thereof reaches the movable unit (72), the movable unit (72) is translatable vertically downwards so as to compress, by means of the first compression element (73), the tube of sheet (TB) at the position of the longitudinal strip (L) of adhesive material, and in order to longitudinally cut the tube of sheet (TB) parallel to the longitudinal strip (L) of adhesive material by means of the first cutting element (74), during the advancement of the tube of sheet (TB), in order to obtain an envelope (B1 , B2, B3) having a width substantially corresponding to the article packed therein, and to reject a strip (SR) of tube of sheet (TB) that is excessive beyond the width of the article.

[0067] The supplementary compression and cutting unit (71) further comprises a first abutting element (75) (for example also constituted by a wheel), arranged inferiorly of the tube of sheet, and arranged and configured in such a way as to be translatable transversally with respect to the tube of sheet, and translatable vertically upwards against the tube of sheet.

[0068] In particular, the first abutting element (75), on the basis of the position assumed by the movable unit (72) and by the first compression element (73), is transversally translated with respect to the tube of sheet (TB) so as to be arranged and positioned opposite the first compression element (73), and then translated upwards to clamp the tube of sheet (TB) between the first abutting element (75) and the first compression element (73), in turn translated vertically downwards against the tube of sheet (TB), in such a way that the tube of sheet (TB) is compressed between the first compression element (73) and the first abutting element (75) at the position of the longitudinal strip (L) of adhesive material, during the advancement of the tube of sheet (TB).

[0069] The machine (M) further comprises a transfer unit (76) comprising at least a loop-wound conveyor belt (77), which is arranged downstream of the supplementary compression and cutting unit (71) and which is configured to receive the excess strip (SR) of tube of sheet and which has been cut from the envelope (B), and to transfer the strip (SR) towards a waste station.

[0070] The machine (M) can advantageously be configured in such a way that the supplementary compression and cutting unit (71) comprises further comprises a second movable unit (82) mounted slidingly along a second guide (830), arranged superiorly and transversally with respect to the tube of sheet (TB), and parallel to the first guide (730), and which is also translatable vertically downwards and thus against the tube of sheet (TB).

[0071] The second movable unit (82) comprises at least a second compression element (83) (for example a rubberised wheel) and a second cutting element (84) (for example a pneumatically-oscillating blade), which are arranged and configured in such a way as to compress the tube of sheet (TB) and cut the tube of sheet (TB) longitudinally, once the second movable unit (82) is translated downwards against the tube of sheet (TB), and consequently to the advancement of the tube of sheet (TB) carried out by the aspirated conveyor belt (4).

[0072] In particular, the second movable unit (82), on the basis of the width of the articles detected by the detection means (85), can be translated along the second guide (83) in order to be positioned in a position with respect to the tube of sheet (TB) corresponding to the position in which the longitudinal strip (L) of adhesive material has been applied on the central part (PC) of the sheet (P) of paper material.

[0073] In this case, a second abutting element (85) is included (for example also constituted by a wheel), arranged inferiorly of the tube of sheet, and arranged and configured in such a way as to be translatable transversally with respect to the tube of sheet, and translatable vertically upwards against the tube of sheet, in order to be able to compress the tube of sheet between it and the second compression element.

[0074] In this case, therefore, the two movable units can be actionable alternatingly between them, in order to compress and cut the tube of sheet longitudinally as a function of the widths of the articles, enabling the tube of sheet to be advanced with a sustained velocity, thus increasing productivity, i.e. the number of envelopes that can be obtained in the unit of time (for example, per minute) (see for example figures 13 and 14, and figures 15 and 16).

[0075] The structure (5) conformed as a tunnel (T) preferably comprises lateral walls (51 , 52) which are arranged along the sides of the conveyor belt (2) and at least an upper wall (53, 54), between the lateral walls (51, 52), while the folder means (4) are configured for folding the lateral parts (PL1, PL2) of the sheet (P) made of paper material about the lateral walls (51, 52) and the upper wall (53, 54) of the structure (5) conformed as a tunnel (T) so as to mutually superpose the two lateral flaps (L1, L2) of the film (P) and form the tube of sheet (TB) wound about the structure (5) conformed as a tunnel (T).

[0076] The lateral walls (51 , 52) of the structure (5) conformed as a tunnel (T) can advantageously be realised in such a way as to comprise a fixed lower part (510, 511) and a movable upper part (520, 521) which is mounted translatably on the lower part (510, 511) and which bears the upper wall (53, 54).

[0077] In this way the position of the upper part (520, 521) of the lateral walls (51 , 52) with respect to the lower part (510, 511) can be regulated and varied in order to vary the distance of the upper wall (53, 54) with respect to the conveyor belt (2) and thus vary the height of the tunnel (T) and adapt it to the effective different heights of the various articles that are to be wrapped in the sheet made of paper material.

[0078] A further advantageous aspect of the wrapping machine of the invention consists in the fact that it comprises means (9) for creating an air cushion between the tube of sheet (TB) and the structure (5) conformed as a tunnel (T).

[0079] This specification enables preventing dragging and therefore friction between the sheet (P), and in particular the tube of sheet (TB) which is under formation, and the walls of the structure (5) conformed as a tunnel.

[0080] In the particular embodiment illustrated in figures 7 and 8, the means (9) for creating an air cushion can comprise pipes (91), connected to a source of compressed air, provided with a series of holes (92) for air passage.

[0081] The pipes (91) are arranged in such a way as to be able to direct air puffs exiting from the holes (92) towards parts of sheet (P) folded against the structure (5) conformed as a tunnel (T).

[0082] For example, the pipes (91) can be arranged along at least a part of the two lateral walls (51 , 52) of the structure (5) conformed as a tunnel (T).

[0083] Further, the means (9) for creating an air cushion can comprise an aspirating mat (93) closed and loop-wound and arranged above the structure (5) conformed as a tunnel (T) in a position that is such as to retain the parts of the sheet (P) folded above the structure (5) conformed as a tunnel (T) by aspiration and activatable in such a way as to be able to accompany the sheet (P) in synchrony with the advancement thereof by the conveyor belt (2). In a further advantageous aspect, the machine (M) comprises photo-detecting means (96) arranged along the tunnel (T) for detecting the passage of the articles (A) internally of the tunnel (T) and to detect the distance between the articles (A), and can be configured such that the compression and cutting means (7) are maintained non-operative when the photo-detecting means (96) detect that the distance between two consecutive articles is less than a predetermined minimum distance.

[0084] This enables avoiding damage to articles which are too close to one another to have a sufficient space for the activating of the compression and cutting means (7).

[0085] In the illustrated preferred embodiment, the second glue application means (6) comprise at least a glue dispenser (61), fixed abutting elements (62, 63) predisposed downstream of the dispenser (61), with respect to the transport direction (E) of the sheet (P), so as to superiorly abut the superposed flaps (L1 , L2) of the sheet (P) and facilitate mutual adhesion thereof, and at least a movable abutting element (64) activatable in a case of halting of the conveyor belt (2) in order to be positioned above the two superposed flaps (L1, L2) of the sheet (P) and to maintain the flaps (L1 , L2) mutually superposed and thus to maintain the tube of sheet (TB) closed.

[0086] An article loading station (8) can be provided, positioned at an initial part of the conveyor means (1) and provided with identifying means (81) configured to detect and identify an identifying code applied to the articles (A).

[0087] Lastly a further advantageous aspect relates to the fact that the detecting means (85) are also configured to detect the height of the articles (A) so that the conveyor means (1) can be halted when the detecting means (85) detect passage of an article having a greater height than the height of the tunnel (T).

Claims

CLAIMS1) A machine (M) for wrapping a sheet (P) made of paper material about articles (A) for forming envelopes (B) containing single articles, comprising: conveyor means (1), which are configured for receiving and conveying articles (A) which are to be wound about by a sheet (P) made of paper material according to a conveying direction (D); an aspirated conveyor belt (2), which is arranged consecutively to the conveyor means (1); a supply station (3) of a sheet (P) made of paper material, comprising supply and relay means (31) for feeding the sheet (P) made of paper material between the conveyor means (1) and the aspirated conveyor belt (2), transversally to the conveying direction (D) of the articles (A), and for arranging the sheet (P) made of paper material with a relative central part (PC) resting on the aspirated conveyor belt (2) and with lateral parts (PL1, PL2) in relation to the central part (PC) laterally projecting from the aspirated conveyor belt (2), so that the articles (A) conveyed by the conveyor means (1) become arranged above the central part (PC) of the sheet (P) made of paper material arranged resting on the aspirated conveyor belt (2) and in that the sheet (P) made of paper material, with the articles (A) arranged on the relative central part (PC), can be retained by aspiration by the aspirated conveyor belt (2) and advanced in a transport direction (E); folder means (4), arranged and configured with respect to the aspirated conveyor belt (2) so as to be able to abut and fold the lateral parts (PL1 , PL2) of the sheet (P) made of paper material that are laterally projecting from the aspirated conveyor belt (2); a structure (5) associated to the aspirated conveyor belt (2) and which is conformed in such a way as to define a tunnel (T) for passage of the articles (A) transported by the aspirated conveyor belt (2) above the central part (PC) of the sheet (P) made of paper material, with the folder means (4) being conformed and configured in such a way as to abut the lateral parts (PL1, PL2) of the sheet (P) made of paper material laterally projecting from theaspirated conveyor belt (2), during advancement thereof, and to fold the lateral parts (PL1, PL2) about the structure (5) conformed as a tunnel (T) so as to superpose the two lateral flaps (L1, L2) of the sheet (P) made of paper material and form a tube of sheet (TB) which is wound about the structure (5) conformed as a tunnel (T); first application means (20) of adhesive material, which are arranged in an area between the conveyor means (1) and the aspirated conveyor belt (2) and which are configured to apply transversal strips (S) of adhesive material on the portion of the sheet (P) made of paper material, which will then be arranged above the aspirated conveyor belt (2) going to form the central part (PC) of the sheet (P) made of paper material which is retained by aspiration by the aspirated conveyor belt (2), with the transversal strips (S) of adhesive material being reciprocally spaced on the basis of the length of the articles (A), in the longitudinal direction of the central part (PC) of the sheet (P), i.e. in the transport direction (E), which are to be packed; second application means (6) of adhesive material, which are positioned above the structure (5) conformed as a tunnel (T) and which are configured to apply adhesive material on at least one of the two flaps (L1, L2) of the sheet made of paper material (P) before the superposing thereof to form the tube of sheet (TB); compression and cutting means (7), which are positioned downstream of the structure (5) conformed as a tunnel (T), at an interruption of the aspirated conveyor belt (2), and which are activatable to transversally clamp the tube of sheet (TB), first anteriorly and then posteriorly with respect to the position of an article (A) in the tube of sheet (TB), at respective two transversal strips (S) of adhesive material between which the article (A) has been positioned, so as to realise the closing and cutting of the tube of sheet (P) and obtain an envelope (B) containing the article (A) internally thereof, characterised in that it comprises a detecting station (80) which is arranged along the conveyor means (1) and comprising detection means (85) which are arranged and configured in such a way as to detect the width of the articles(A), in a transversal direction with respect to the conveying direction (D) thereof towards the aspirated conveyor belt (2), wherein the machine (M) is configured in such a way that the first application means (20) of adhesive material, on the basis of the data provided by the detection means (85) in relation to the detected width of the articles (A) which are advancing along the conveying direction (D) towards the aspirated conveyor belt (2), are also activatable, should the width detected for a given article be smaller than a predetermined width corresponding to a maximum width for an article to be packed, substantially identical to the width of the central part (PC) of the sheet (P) of paper material: in order to apply two respective transversal strips (S) of adhesive material, spaced from one another by a distance of at least equal to the length of the article to be packed and having an extension, starting from a first edge (PC1) of the central part (PC) of the sheet (P) of paper material, at least equal to the width detected for the given article, and in order to apply at least a longitudinal strip (L) of adhesive material, longitudinally on a portion of the central part (PC) of the sheet (P) of paper material, and transversally to the two respective transversal strips (S) of adhesive material, at a distance from the first edge (PC1) of the central part (PC) of the sheet (P) at least equal to the width detected for the article to be packed; and wherein the compression and cutting means (7) comprise at least a supplementary compression and cutting unit (71) which is configured, when the detection means (85) detect that an article (A) has a width that is smaller than the predetermined width and as a consequence of the application of the at least a longitudinal strip (L) of adhesive material on a portion of the central part (PC) of the sheet (P) of paper material, in order to be activatable in such a way as to longitudinally compress the tube of sheet (TB) at the position of the longitudinal strip (L) of adhesive material and in order to longitudinally cut the tube of sheet (TB) parallel to the longitudinal strip (L) of adhesive material in order to obtain an envelope (B1 , B2, B3) having a width substantially corresponding to the article packed therein, and to reject a strip (SR) of tube of sheet (TB) that is excessive beyond the width of the article.2) The machine (M) as claimed in claim 1 , wherein the supplementary compression and cutting unit (71) comprises at least a movable unit (72) which is mounted vertically slidingly along a first guide (730), arranged superiorly and transversally with respect to the tube of sheet (TB), and which is translatable vertically downwards and thus against the tube of sheet (TB), wherein the movable unit (72) comprises at least a first compression element (73) and a first cutting element (74) which are arranged and configured in such a way as to be able to compress the tube of sheet (TB) and in order to be able to cut the tube of sheet (TB) longitudinally, wherein the movable unit (72), on the basis of width of the articles detected by the detection means (85), is translatable along the first guide (730) in order to be positioned in a position with respect to the tube of sheet (TB) corresponding to the position in which the longitudinal strip (L) of adhesive material has been applied on the central part (PC) of the sheet (P) of paper material, and then, when the tube of sheet (TB) with the article (A) internal thereof reaches the movable unit (72), the movable unit (72) is translatable vertically downwards so as to compress, by means of the first compression element (73), the tube of sheet (TB) at the position of the longitudinal strip (L) of adhesive material, and in order to longitudinally cut the tube of sheet (TB) parallel to the longitudinal strip (L) of adhesive material by means of the first cutting element (74), during the advancement of the tube of sheet (TB), in order to obtain an envelope (B1 , B2, B3) having a width substantially corresponding to the article packed therein, and to reject a strip (SR) of tube of sheet (TB) that is excessive beyond the width of the article.3) The machine (M) as claimed in claim 2, wherein the supplementary compression and cutting unit (71) further comprises a first abutting element (75), arranged inferiorly of the tube of sheet (TB) and configured in such a way as to be transversally translatable with respect to the tube of sheet (TB), and translatable vertically upwards against the tube of sheet (TB), wherein the first abutting element (75), on the basis of the position assumed by the movable unit (72) and by the first compression element (73), is transversally translated with respect to the tube of sheet (TB) so as to be arranged and positioned opposite the first compression element (73), and then translated upwards toclamp the tube of sheet (TB) between the first abutting element (75) and the first compression element (73), in turn translated vertically downwards against the tube of sheet (TB), in such a way that the tube of sheet (TB) is compressed between the first compression element (73) and the first abutting element (75) at the position of the longitudinal strip (L) of adhesive material, during the advancement of the tube of sheet (TB).4) The machine (M) as claimed in any one of claims from 1 to 3, comprising a transfer unit (76) comprising at least a loop-wound conveyor belt (77), which is arranged downstream of the supplementary compression and cutting unit (71) and which is configured to receive the excess strip (SR) of tube of sheet (TB) and which has been cut from the envelope (B), and to transfer the strip (SR) towards a waste station.5) The machine (M) as claimed in any one of the preceding claims, wherein the structure (5) conformed as a tunnel (T) comprises lateral walls (51 , 52) which are arranged along the sides of the aspirated conveyor belt (2) and at least an upper wall (53, 54), between the lateral walls (51 , 52), and wherein the folder means (4) are configured for folding the lateral parts (PL1 , PL2) of the sheet (P) made of paper material about the lateral walls (51, 52) and the upper wall (53, 54) of the structure (5) conformed as a tunnel (T) so as to mutually superpose the two lateral flaps (L1 , L2) of the sheet (P) and form the tube of sheet (TB) wound about the structure (5) conformed as a tunnel (T).6) The machine (M) as claimed in the preceding claim, wherein the lateral walls (51 , 52) of the structure (5) conformed as a tunnel (T) comprise a fixed lower part (510, 511) and a movable upper part (520, 521) which is mounted with freedom to translate on the lower part (510, 511) and which bears the at least an upper wall (53, 54) so that the position of the upper part (520, 521) with respect to the lower part (510, 511) can be regulated and varied in order to vary the distance of the upper wall (53, 54) with respect to the aspirated conveyor belt (2) thus varying the height of the tunnel (T).7) The machine (M) as claimed in any one of the preceding claims, comprising means (9) for creating an air cushion between the tube of sheet (TB) and thestructure (5) conformed as a tunnel (T).8) The machine as claimed in claim 7, wherein the means (9) for creating an air cushion comprise pipes (91), connected to a source of compressed air, and provided with a series of holes (92) for air passage, the pipes (91) being arranged in such a way as to be able to direct air puffs exiting from the holes (92) towards parts of sheet (P) folded against the structure (5) conformed as a tunnel (T).9) The machine (M) as claimed in any one of claims 7 and 8, wherein the means (9) for creating an air cushion comprise an aspirating mat (93) closed and loop-wound and arranged above the structure (5) conformed as a tunnel (T) in a position that is such as to retain the parts of the sheet (P) folded above the structure (5) conformed as a tunnel (T) by aspiration and activatable in such a way as to be able to accompany the sheet (P) in synchrony with the advancement thereof via the aspirated conveyor belt (2).10) The machine (M) as claimed in any one of the preceding claims, comprising photo-detecting means (96) arranged along the structure (5) conformed as a tunnel (T) and configured to detect the passage of the articles (A) internally of the tunnel (T) and to detect the distance between the articles (A) and wherein the heat welding and cutting means (7) are configured in such a way as to be non-operative when the photo-detecting means (96) detect that the distance between two consecutive articles is less than a predetermined minimum distance.11) The machine (M) as claimed in any one of the preceding claims, wherein the second glue application means (6) comprise at least a glue dispenser (61), fixed abutting elements (62, 63) predisposed downstream of the glue dispenser (61), with respect to the transport direction (E) of the sheet (P), so as to superiorly abut the superposed flaps (L1 , L2) of the sheet (P) and to facilitate mutual adhesion thereof and at least a movable abutting element (64) activatable in a case of halting of the aspirated conveyor belt (2) in order to be positioned above the two superposed flaps (L1, L2) of the sheet (P) and to maintain the two superposed flaps (L1, L2) mutually superposed and thus tomaintain the tube of sheet (TB) closed.12) The machine (M) as claimed in one of the preceding claims, comprising an article loading station (8) positioned at an initial part of the conveyor means (1) and provided with identifying means (81) configured to detect and identify an identifying code applied to the articles (A).

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