Machine for packaging products in a mesh bag with a handle

Abstract: A tubular mesh feeder (2), a set of rollers in quincunxes (10,11,12), a frame with another set of rollers (13,14,15) resting, respectively, on the former (5), feeders of two bands (16,17), plates (6,7) with springs (8,9) between both bands (18,19), parts shaping folds on the free parts of the mesh, rollers (3,4) that pull the tubular mesh with its two bands welded and means (31,32) that close the bottom and cut the top of each bag, feeder rollers of a band and means for transversally cutting it to obtain a strip, turning means that fold the strip in "U", means for inserting the strip in the upper part of the bag and means for welding this set.

Description: The invention relates to packing machines for packing products in a mesh bag having a handle. The products to be packed may be fruit, vegetables or others, food products of all classes and, in general, any product or object to be packed forming a bag, normally with a total weight or predetermined amount. Generally, the tubular mesh forming the bag is made of plastic material. An automatic machine for shaping and continuous closing of mesh bags obtained from a tubular network is known, which is the purpose of Spanish Invention Patent no. 475.372 granted to Mr. Agustin Dauder Guardiola. This machine is basically characterized by the fact it includes a set of two vertical telescopic tubes with the inside fixed and the outside mobile. A third removable tube is placed on the set that carries a certain amount of the tubular mesh. In turn, the set of the three tubes is communicated at the top with the hopper supplying the products to be packed, which have previously been measured in weight and number. The mobile tube is activated in the downwards axial direction by an adjustable stroke cylinder, thus pulling the part of the mesh envisaged for shaping the bag with suitable capacity for the amount of supplied product, which requires having previously carried out the closure of its base or lower end, and returning the mobile tube to its initial position immediately. There are means that gather, and collect the mesh part provided, having two sets of blades each and which act on both sides of the mesh, moving it in a horizontal transversal plane with respect to the axis of the mesh on level with the lower end of the mobile tube in its initial position. Said sets of blades overlap in their active position, the upper one providing a support for the bottom of the bag that received the product discharged by the hopper. The blades of the upper set have a narrow part that, in collaboration with the angular edge of the blades of the opposite set, shape the gathering of the mesh. On the bottom of the narrow part there is a cutting and stapling lather head, which is integral with the upper blade set and located on the virtual axis of the telescopic set. Operation of the lather head causes the mouth of the already filled bag and the bottom of the next bag to close. Then the blades are separated and a new cycle is started. The bags obtained from said machine do not have a handle and each bag is filled with its bottom resting on a stiff support resulting from the set constituted by the upper pair of blades, so that the first parts of the product to be packed hit the stiff support with the mere overlapping of the mesh. As regards another known machine, an additional band to print data (type, class, weight and others) of the products contained in the bags and/or to identify their origin must be added. This band is secured only by welding it at two ends and the rest is free, that is, bags without a handle are obtained from this machine. Furthermore, the structure of the known machine gives rise to a limited performance due to the time it takes to prepare it and the welding. Also known is a conventional machine supplying a plastic material band, specifically a mesh material, that cuts a piece of the band at a certain length based on the size of the bag to be obtained, folds it horizontally in the middle and joins it by heat welding or sewing of the vertical ends of the two opposite walls. Normally, two joined handles are respectively fastened to each of the two walls of the bag so obtained. This bag has the disadvantages of increase in the fabrication cost and that it cannot be closed in the case of an eventual and more than probable fall of the products contained therein. Furthermore, it cannot be completely filled as its mouth is not closed and therefore does not guarantee the content of the bag for the buyer. According to the above, the upper mouth of this last bag remains open and does not constitute a closed bag with the products inaccessible to the buyers, the access of which implies breaking the upper part by conventional means (for example, scissors). On the other hand, the bags open at the top are used by the buyers for filling them with the products they purchase in shopping centers and these bags are bought in specific shops, whilst the closed bags are closed packages once full and, to this effect, sealed, particular to the products to be sold by the shops in question. In other words, said bags have another application than the closed bags and their marketing channels are different. European Patent Publication No. 1 053 939 A1 describes an apparatus for producing netting packages for horticultural products using continuously unwound tubular netting. The apparatus includes means for applying lateral bands to sides of the netting packages and means for filling the bags with horticultural products. It is one object of the present invention to provide improved packing machines for packing products in a mesh bag having a handle. This object is achieved by the packing machine of claim 1. A further development of the invention is found in claim 2. The improvements in the packing machines for packing products in mesh bags having a handle, according to the invention, provide amongst others the following advantages with regard to what is known: a) The bands are not free as each one is fastened to the mesh of each bag at both sides. b) There is no mobile tube to push and transport each bag with it being returned in ascent. Instead there is a lower transport of the mesh with the two bands by pulling means with the resulting increase in speed and better performance. c) The bags obtained have an initially flat handle made of a strip with folds that unfolds when used. d) The final handle, that is attached to the full and closed bag, offers the bag carrier a flat part that opens on being unfolded and conveniently adapts itself to the hand and distributes the stress arising from the weight of the filled bag. e) When the bags are filled with the desired products, their base does not rest on a stiff support, thus the products receive better treatment, especially delicate ones. The improvements in packing machines for packing products in mesh bags having a handle, which are the purpose of the invention, provide the advantages described above, apart from others that will be easily inferred from the embodiment described in detail below. In order to facilitate understanding of the characteristics mentioned above and at the same time to make known various details, drawings are attached to this description in which a practical embodiment is represented as an example and is not limitative of the scope of this invention. Figure 1 shows a schematic elevation side view of the portion of a packing machine for packing products in mesh bags according to an embodiment of the invention where the bag is made and its lower base or bottom is closed. Figure 2 corresponds to a schematic front elevation view of said portion of the packing machine where the bag is made and its lower base or bottom is closed. Figure 3 is a schematic front elevation view of another portion of the packing machine where the handle is formed and fastened to the mouth of the bag. Figure 4 shows a schematic side elevation view of the portion of the packing machine where the handle is formed and fastened to the mouth of the bag. It must be taken into account in what follows that the explanation made refers to a static situation of some elements, when in fact and with the packing machine in normal operation, these elements turn or move. However, this will be obvious after reading the description that follows. In accordance with figures 1 and 2 of the drawings, the station where the mesh bag is made and its lower base is closed in a packing machine provided with the improvements of the invention includes the tubular mesh -1- coming from the reel -2- that is moved downwards by a pair of rollers -3- and -4-, one of which at least is motorized. The tubular mesh -1- moves around a vertical frame -5- in the way of a template or form, with a very reduced thickness as regards the width. Thus, the tubular mesh adopts an elongated transversal shape with two very close faces. On the lower part and inside the frame -5- there are two opposite vertical plates -6- and -7- that are biased (driven) towards the outside by elastic means such as the springs -8- and -9-, which push them against the inside faces of the mesh to be moved downwards. There is a variable number of loose rollers on the chassis of the packing machine, such as the three horizontal rollers -10-, -11- and -12- arranged in quincunxes from top to bottom. The frame or form -5-, in turn, has a variable number of loose rollers, such as the three horizontal rollers -13-, -14- and - 15- that respectively rest on the three rollers -10-, -11- and - 12-. Between these and the rollers of the frame -5- the tubular mesh is moved, following a sinusoidal path (see figure 2). At a certain height and lower than the mentioned sinusoidal path of the mesh, there are two opposite feeders of both bands, such as the reels -16- and -17- that provide both bands -18- and -19- with thermoplastic material, which by means of two rollers -20- and -21- are superimposed on the descending mesh and then welded to it by two welding means -22- and -23-. These, in turn, go in pairs (figure 1). The welding means carry out the heat welding of the two sides of each band to the mesh. The bands -18- and -19- may include data relating to the products to be contained in the bags and their origin and the data may be on one or both bands. Underneath the welding means there are two opposite, vertical and flat wheels -24- and -25- that form two folds -26-and -27- towards the inside (figure 1) of the parts of the mesh without the bands. Going always from top to bottom, there is then a variable number of pairs of rollers, such as the pair of opposite, horizontal rollers -3- and -4- that turn in opposite directions and are applied externally against the set constituted by the tubular mesh and the two bands, pulling it downwards. After that are some welding means, such as the two welds -28- and -29- that close the free bottom of the mentioned set with a heat weld - 30-. Underneath this are cutting means, such as the cutters -31- and -32- that cut what will be the end of the upper part of a bag, thus obtaining a bag with its mouth open and with two opposite folds. In figures 1 and 2 the packing machine shows the welds -28- and -29- and the cutting means or cutters -31- and -32- open, that is, in the inactive position, whilst in the description made it is presumed they are in the active position and coordinated, which is what would happen in practice. The bags obtained according to the above description are then transported hanging and with their mouth open, which is expanded by conventional means, passing by a filling station with the desired products. Then each filled bag is closed at a certain distance below its mouth, establishing a free, upper and continuous band. The filled and closed bags are transported to the station where the handle is made and joined to the mouth of the corresponding bag. In this last station of the packing machine (figures 3 and 4) there are feeder rollers, such as the rollers -33- (this one motorized) and -34- (pressure). This last roller (which has a spring or other means to maintain a certain pressure against the roller -33- with the element to be moved inserted) is not represented in figure 4, where only the mechanisms of the handle making stage and a finished bag are sketched. The rollers -33- and -34- supply a thermoplastic material band -35- in the downwards direction coming from a reel -36-. When a motorized roller is qualified, this is understood to be operated by a motor, usually electric and, where applicable, through transmission means. Next are transversal cutting means -37- for cutting the band -35- into strips -38-. Each strip is transported via a pair of vents -39a- and -39b- to a motorized roller -40-. This roller is linked, for example by a chain or cogged belt, to another roller -41- which, in turn, has a plate -42- joined to it that can be moved downwards or upwards. The two vents are placed at the ends of both arms -a- and -b- (figure 4). Once the vents have been attached by vacuum to the strip -38-, their arms make them turn in the opposite direction according to a 90° angle, shaping the handle -45- in an inverted "U" general shape and with the branches folded as represented in figure 4. The vents deposit the two ends of the handle on the roller -40-. At this moment a counter-roller -43- joined to the end of an arm -44-, which may move according to the arrow of figure 3, is applied against the roller -40- with interposition of the ends of the handle. The vacuum of the vents is broken and the arms -a- and -b- turn in the opposite direction to the one before waiting to receive the next strip. When the roller -40- is activated, turning according to the arrow of figure 3, it pulls the handle -45- downwards, in collaboration with the counter-roller -43-, and at the same time turns the roller -41- causing the plate to descend -42-. The lower end of said plate is applied against the free ends of the handle, resulting in two folds (these are schematically represented in the lower part of the handle -45- of figure 3), moving the handle downwards inside the guide -46- until reaching the welders -47- that fasten it to the upper free band of the bag, prior to inserting the two ends of the handle inside the space delimited by the band (see figure 3). In this way, bags filled with the desired products, closed and provided with a handle for easy carrying are obtained, such as the bag -48- represented in figure 3 just before the welders -47- come into operation to fasten the handle and the bag -49 represented in figure 4, in which the handle has been fastened by welding. It should be mentioned that, during performance of the improvements that are purpose of this invention, all the detail variations that experience and practice make advisable as regards shapes and sizes, both absolute and relative, materials used and other circumstances of an accessory nature may be applied, as well as whatever constructive detail modifications considered compatible with the essentiality of what is claimed may be introduced, provided they are considered in the scope of the following claims.

Claims: A packing machine for packing products in a mesh bag (49) having a handle (45), comprising, in a linked way, means (2) for supplying a tubular mesh (1), two opposing vertical feeders (16, 17), each adapted to feed a lateral thermoplastic band (18, 19), a vertical frame (5) adapted to shape the bag, means (28,29) for closing the bottom of the bag by heat welding, means (31, 32) for cutting the bag at the top, means for filling the bag with the products, means for closing an upper mouth of a filled bag and means for transporting the filled, closed bag towards a machine exit, characterized by : a set of at least three horizontal loose rollers (10, 11, 12) being located in quincunxes from top to bottom, the tubular mesh being interposed and moving between the vertical frame and said set of rollers, wherein at least three additional horizontal rollers (13, 14, 15) respectively rest on corresponding rollers of said set of rollers where the tubular mesh is inserted, the two opposing vertical feeders being located underneath the loose rollers, two opposing vertical plates (6, 7) on the vertical frame being pushed outwardly by elastic means (8, 9) against respective portions of the inside surface of the tubular mesh, where the respective thermoplastic bands are superimposed against means (22, 23) for heat welding the two sides of each band to the tubular mesh, underneath the heat welding means (22, 23), two vertical, opposing flat wheels (24, 25) adapted to shape two folds (26, 27) towards the inside of the mesh parts that are free of the bands, and at least two opposing, horizontal rollers (3, 4) being located lower than the flat wheels, turning in opposite directions and being applied externally against the combination of the tubular mesh and the two thermoplastic bands for their transport. A packing machine in accordance with claim 1,further comprising downstream of the filling means, where the bag is filled with the products, and the closing means, where the bag is closed at a certain distance underneath the mouth: feeder rollers (33, 34) for supplying a thermoplastic material band (35), means (37) for transversally cutting the band into a strip (38), two opposing turning lever means (a, b) on the same plane for folding the strip into an inverted "U" shaped with its free ends being folded onto each other, and means (40, 42-44, 46) for inserting the folded strip into an upper part of the open mouth of the bag and for welding the bag to the ends of the strip, thereby obtaining a closed bag (49) with the handle (45).

Inventors: DAUDER GUARDIOLA AGUSTIN, DAUDER GUARDIOLA, AGUSTIN
Applicants: DAUMAR TALLERES, TALLERES DAUMAR S.A.
Application year: 2001
Main classification: B65B9
IPC codes: B31B1, B31B23, B65D30, B65B9, B65D33, B65B61