Abstract:
The invention relates to a method and an apparatus for covering printed products with a packaging material in the form of a continuous packaging material web, especially a plastic film. In each case, at least two printed products are deposited beside each other on the packaging material web by means of a feed device. In each case, at least two printed products lying beside each other are covered simultaneously with the packaging material and subsequently divided from each other. The invention permits the packaging rate to be doubled in a simple way, without having to carry out complicated modifications to the packaging apparatus.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a method and an apparatus for covering printed products with a packaging material.  
         BACKGROUND OF THE INVENTION  
         [0002]    Individual printed products or a group of a number of printed products are packed for dispatch by being covered on all sides with a wrapper, paper or a film or inserted into envelopes. One method of packing printed products, in which the latter are inserted into packaging elements which are located in insertion compartments in a packing drum, is disclosed by U.S. Pat. No. 5,615,537. With this method, a high throughput of products to be packed is possible, and it necessitates prefabricated packing elements and is therefore correspondingly expensive.  
           [0003]    German Patent No. DE-A 31 02 872 discloses a method of covering chocolate bars and the like, in which a continuous packaging material, a metal foil, is folded over to form a tube which is open on one side and has a U-shaped cross section. Bars lying one behind the other in a row are placed into said tube, the open side of the tube then being closed and individual pack units being divided off.  
         SUMMARY OF THE INVENTION  
         [0004]    The invention is based on the object of specifying a method and an apparatus for packing printed products with which a high throughput can be achieved with the lowest possible material and processing costs per pack unit.  
           [0005]    According to the invention, at least two printed products are packed in parallel with a common packaging material web. As a result, the tools which are present to feed products, to unwind and fold over the packaging material, especially a plastic film, and to close and, if necessary, divide off the pack units can advantageously be used twice over. The packing rate can be doubled at constant processing speed. According to the invention, the packaging material web is itself used as a transport medium after the printed products have been deposited on it. The material web preferably runs over a support which accommodates the weight of the printed products. It is particularly advantageous if the cross section of the support is bent over upward or downward at right angles to the conveying direction, and has contact elements for printed products, so that the latter assume a defined position with respect to the cutting and closing tools. The continuous packaging material used is preferably a plastic film, but a paper web can also be employed. A plastic film is preferably welded in order to produce the pack, while a paper web is adhesively bonded. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    Exemplary embodiments of the invention are illustrated in the drawing and described below. In the drawing, in purely schematic form:  
         [0007]    [0007]FIG. 1 shows an apparatus for implementing the method;  
         [0008]    [0008]FIGS. 2 a, b  show an example of a method according to the invention, forming a U-shaped, laterally open material tube;  
         [0009]    [0009]FIGS. 3 a, b  show an example of a method according to the invention, forming a material tube closed at the top;  
         [0010]    [0010]FIGS. 4 a, b  show an example of a method according to the invention, forming a material tube open at the top;  
         [0011]    [0011]FIGS. 5 a, b  show a further example of a method according to the invention, forming a material tube open at the top;  
         [0012]    [0012]FIGS. 6 a, b  show an example of a method according to the invention, forming two pockets from a packaging material web;  
         [0013]    [0013]FIGS. 7 a - d  show an example of a method according to the invention, forming a loop of packaging material between the printed products;  
         [0014]    [0014]FIGS. 8 a - d  show a further example of a method according to the invention, forming a loop of packaging material between the printed products;  
         [0015]    [0015]FIGS. 9 a, b  show a third example of a method according to the invention, forming a loop of packaging material between the printed products;  
         [0016]    [0016]FIGS. 10 a - c  show three examples of the shape of a support for the packaging material. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]    [0017]FIG. 1 shows, schematically, an apparatus for implementing the method according to the invention. A similar apparatus for packing one product in each case is described in DE-A 31 02 872. In relation to the construction and functioning of the apparatus according to the invention, reference is also made to this disclosure.  
         [0018]    Printed products  1 ,  2  are fed to the apparatus in the conveying direction F in two parallel rows  26 ,  27  by a feed device  25 . The feed device  25  has, for example, a conveyor belt  25 ′ with driving elements  34 , for example rollers, which are arranged at right angles to the conveying direction F and between which printed products lie. Instead of a belt conveyor, cam conveyors, gripper conveyors and clamp transporters and the like can also be used as the feed device. The printed products do not necessarily have to arrive in rows, but, for example, can also arrive in an overlapping formation or can be drawn off from a stationary stack. In this case, it is merely necessary for two printed products in each case to be deposited beside each other on the packaging material, that is to say the packaging material web  3 ′.  
         [0019]    A packaging material web  3 ′, a plastic film here, is unwound over guide rollers  35  from a feed roll  28  oriented at right angles to the feed device  25  and to the conveying direction F. The packaging material web  3 ′ can also be supplied in any other way and laid around the products. The guide rollers  35  are arranged parallel to the feed roll  28 , approximately symmetrically with respect to the plane of the feed device  25 .  
         [0020]    By means of a turner device  30 , which is formed here by pairs of rollers  31 , running at the side of the feed device  25 , and the guide rollers  35 , the initially flat packaging material web  3 ′ is used to form a material tube  3 ′ which has a U-shaped cross section, is open at the sides and has an upper and a lower material layer  8  and  9 , respectively. Said hose is laid around the printed products  1 ,  2  supplied, the latter being deposited on the lower material layer  9  by the feed device  25 . The packaging material web  3 ′ itself is used as a transport medium for the printed products  1 ,  2  after they have been deposited. It is moved in the conveying direction F by the pairs of rollers  31 .  
         [0021]    Above the central area  4  between the printed product rows  26 ,  27  and between the printed products  1 ,  2  there is a first closing device  33  for joining the upper and lower material layers  8 ,  9 . In the present case, the first closing device  33  comprises  2  wheels  33 ′,  33 ″ which can be rotated about a common axis and with which the layers  8 ,  9  are joined to each other continuously, being welded here, so that two welds running in parallel in the conveying direction F are produced. In order then to divide the pack units of one row  26  from those of the other row  27 , a blade  36  oriented in the conveying direction F is arranged as a dividing device downstream of the first closing device  33 . Alternatively, a dividing device can also be integrated into the closing device  33 , for example a blade can be arranged between the wheels  33 ′,  33 ″ between the welds. In the area of the edge  10 , there is arranged a continuously operating second closing device  32 , which likewise welds the upper and lower material layers  8 ,  9  in the edge area in the conveying direction F. Arranged downstream of the first closing device  33 , in the conveying direction F, is a third closing device  29  which, transversely with respect to the conveying direction F, joins the packaging material webs (welds them here) in the region between two successive printed products at regular time intervals matched to the conveying speed and the product spacing. Using a second dividing device with a blade  37  oriented transversely with respect to the conveying direction, a finished pack unit is then divided off. It is possible for the second dividing device to be dispensed with for those applications in which the printed products are to be stored temporarily individually packed in a continuous material web tube.  
         [0022]    [0022]FIGS. 2 a ) and  b ) show two steps in a variant of the method according to the invention, in schematic form. The method can be implemented with the apparatus shown in FIG. 1. A packaging material web  3 ′ in the form of a plastic film is used to form a material tube  3 ″ which has a U-shaped cross section, is open at the side and has an upper and a lower material layer  8  and  9 , respectively. Two printed products  1 ,  2 , which arrive in parallel printed product rows, as shown in FIG. 1, are placed beside each other on the lower material layer  9 . In the central area  4  between the two printed products  1 ,  2 , the lower and the upper material layers  8  and  9  are welded to each other, forming welds  5 ,  6  running in the conveying direction F, the packaging material web  3 ′ being divided between them along a cutting line  7  likewise running in the conveying direction F. Alternatively, a wide weld can be formed, which is divided at its center, so that the upper and lower material layers in each case remain joined. To the side of one of the printed products  2 , an edge  10  comprising upper and lower material layers  8 ,  9  projects, and is closed by a further weld  11  running in the conveying direction. In the area between printing products lying one behind the other, the packaging material web  3 ′ is finally welded and cut transversely with respect to the conveying direction F, in order to complete the packaging and to separate printed products which arrive one after the other from one another.  
         [0023]    [0023]FIGS. 3 a ),  b ) show two steps in a further variant of the method according to the invention, in schematic form. The printed products  1 ,  2  are deposited beside each other on the packaging material web  3 ′, to be specific approximately at the center. In this case, first and second outer material areas  12 ,  13  in each case project laterally outward, which is illustrated by dashed lines. The projecting first and second outer material areas  12 ,  13  are then folded over toward the central area  4  to form a tube  3 ″ of packaging material. The folded-over first and second outer material areas  12 ,  13  are sufficiently long that they overlap each other in an overlap area  14 . In this overlap area  14  between the printed products  1 ,  2  arranged beside each other, they are welded to each other and to the material layer lying underneath in one operation. As in the method of FIG. 2, two parallel welds  5 ,  6  can be applied, a cut being made between them, cutting line  7 . This variant has the advantage over the variant of FIG. 2 that, in addition to the necessary welding and dividing transversely with respect to the conveying direction, only one closing device operating in the conveying direction or only one operation is needed in order to form two packs.  
         [0024]    [0024]FIGS. 4 a ),  b ) show two steps in a further variant of the method according to the invention, in schematic form, similar to the method from FIGS. 3 a ),  b ). The laterally projecting first and second outer material areas  12 ,  13  are shown shorter here than in FIGS. 3 a ),  b ), so that they do not overlap when folded over toward the central area  4 . They are then welded individually onto the lower material layer  9 , in each case with a weld  5 ,  6 . The area between them is cut along the cutting line  7 .  
         [0025]    In the variant of the method according to the invention shown in FIGS. 5 a ),  b ), the printed products are again placed approximately centrally on the packaging material web  3 ′, and the projecting first and second outer material areas  12 ,  13  are turned over toward the center. In the central area  4 , the packaging material web  3 ′ is cut along the cutting line  7 . The first and second inner material areas  15 ,  16  formed as a result are turned over outward, so that they overlap the first and second outer material areas  12 ,  13 . In the overlap area on the flat side of the products  1 ,  2 , the first and second material areas  12  and  15  and  13  and  16 , respectively, are welded to each other (welds  5 ,  6 ).  
         [0026]    In the variant of the method according to the invention shown in FIGS. 6 a ),  b ), the printed products  1 ,  2  are inserted, standing upright, into two parallel loops  23 ,  24  made of a single packaging material web  3 ′ having a U-shaped cross section in each case. The packaging material  3  is severed in the axial direction along a cutting line  7  in the center between the loops. The two material layers of a loop are in each case welded to each other, the welds  5 ′,  6 ′ in this case being applied in the horizontal direction.  
         [0027]    [0027]FIGS. 7 a ) to  d ) show, in schematic form, four steps in a further variant of the method according to the invention, in which the film-like packaging material  3  is drawn up or forced up in the central area  4  between the two deposited printed products  1 ,  2 , forming a loop  22 , FIGS. 7 a ),  b ). The loop  22  has a length L 1  and the laterally projecting outer material areas  12 ,  13  have a length L 2 , the sum L of the lengths L 1  and L 2  being greater than the width B of the printed products  1 ,  2 . In addition, L 1 &gt;B here. The loop  22  is cut centrally at the highest point, cutting line  7 , so that loose inner material areas  15 ,  16  are formed. These are turned over outward and in each case joined to the outer material areas  12 ,  13  by welds  5 ,  6 , FIGS. 7 c ),  d ).  
         [0028]    [0028]FIGS. 8 a ),  b ),  c ) and  9   a ),  b ) show modifications of this method from FIGS. 7 a ),  b ). In FIGS. 8 a ),  b ),  c ), the length L 1  of the loop  22  is less than the length L 2  of the outer material areas  12  and  13 , and L 1 &lt;B. The outer material areas  12  and  13  are folded inward, and the inner material areas  15  and  16  are folded outward after the loop  22  has been divided. The material areas are joined to each other in the overlap area on the flat side of the products  1 ,  2 . In FIGS. 9 a ),  b ), the loop  22  has a length L 1  which is somewhat greater than half the width B of the printed product. Inner and outer material areas  12 ,  13 ,  15 ,  16  are folded outward and inward, respectively. In the case of the method from FIGS. 8 and 9, welding can advantageously be dispensed with if the material areas overlap to a sufficient extent, since the covering is sufficiently stable because of the transverse welding (not shown).  
         [0029]    Finally, FIGS. 10 a ) to  c ) show three variants of supports  17 ,  18 ,  19  for the packaging material  3  and the printed products  1 ,  2 . The film-like packaging material  3 , not illustrated in FIGS. 10 a ) and  10   b ), is in each case located between the support and the printed products  1 ,  2 . A flat support  17  is shown in FIG.  10   a ). It preferably has an aperture (not illustrated) in the central area  4 , in order, in accordance with the method variant illustrated in FIGS.  7  to  9 , to be able to form a loop of film by means of pressure from below. The support  18  from FIG. 10 b ) is bent in a V shape in the cross section, so that the printed products  1 ,  2  placed on the packaging material web (not illustrated here but lying on the support) slide toward the central area  4  because of the force of gravity. In order to produce a defined position of the printed products  1 ,  2  in relation to each other and in space, the support  18  has contact elements  20 , for example webs, in the central area  4 , on which the printed products  1 ,  2  rest. The support  19  from FIG. 10 c ) is likewise bent with a cross section in the shape of a saddle roof and a tip pointing upward. Printed products  1 ,  2  placed onto the support  19  or onto the packaging material web  3 ′ lying thereon slide outward, on account of the force of gravity, and are retained by contact elements  21 , which are formed by a step in the support  19 .  
         [0030]    While preferred embodiments of the invention have been described, it should be understood that the invention is not so limited, and modifications may be made without departing from the invention. The scope of the invention is defined by the appended claims, and all methods and devices that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.