Method and machine for packaging vegetable products in a mesh bag with a handle

Abstract

 From a spool (7), the mesh tubing (6) is fed to a floating wedge (4) through which inside said tubing (6) travels, pulled by a pair of traction (9) rollers, said wedge having the purpose of achieving lateral folds of the tubing (6) which gives it a bellows-type structure. A cutting and welding assembly (12-13-14) is arranged immediately below the rollers (9), fragmenting the tubing (6) and creating bags closed at their bottom and with a mouth oriented downwardly, which sequentially couple radial and equiangularly-distributed forms (16) over a rotor (17), so that said forms open the bags and, emerging each from the rotor, they swing 180° to a lower extreme position in which their filling occurs at the expense of the dose of product (23) housed in the core itself of the rotor, immediately after which the full bag is moved to a closing station where parallely to the closing by welding of the bag a lift handle is introduced thereon.

Description

Object of the Invention

[0001] The present invention refers to a process for packaging fruit and vegetable products in which a continuous mesh-and-straps tubing is used as a packaging base, suitably fragmented to conform, bags which, after receiving the corresponding fruit dose inside, are closed for their distribution.

[0002] The invention also refers to the machine for carrying out said process.

Background of the Invention

[0003] The changes that have occurred in the fruit and vegetable product packaging sector in the last years are known, essentially due to the need of meeting the demands that the large purchasing and distribution groups have imposed on the packagers.

[0004] In this respect, filling machines for netted sacs provided with straps or the like typical for packaging products of the types stated above, have been developed. In this sense, Spanish patent no. 2082689 can be mentioned. Machines for the stated object, which preform or conform the packing case from tubing mesh webs and printed straps are also known. These machines make the bags "in situ" from webs of tubing, woven or extruded mesh and printed straps.

[0005] Although the machines for the stated purpose meet the currently existing demand, they have different drawbacks.

[0006] On the one hand, the fixing of the side strips to the woven mesh can only be achieved at a low rate and with considerable instability. These strips demand a very high basis weight to achieve a minimum welding stability. Moreover, the side strips nust be coated with a nonadherent material, due to being provided with a badly defined welding system, turning this package coating into a composite generating a waste out of regulations.

[0007] On the other hand, the woven mesh used must have a very high, minimum basis weight for obtaining a welding with a minimally stable welding.

[0008] The object of the present invention is to solve the mentioned drawbacks by means of a process and machine that allow to efficiently carry out the packaging of fruit and vegetable products from a preformed mesh-and-straps tubing.

Description of the Invention

[0009] The process involves continuously supplying the mesh-and-straps tubing from a spool, effecting a folding of said tubing body according to what the side edges of the bags must be, which thus adopt a bellows-type structure, fragmenting said tubing in portions corresponding to respective bags, and simultaneously closing the bottom thereof by means of welding, coupling each bag to a form and supplying the 180° planetary motion so that the bag is left with its opening oriented upwardly, discharging the corresponding product dose over the bag, moving each bag to a closing unit in which a handle is simultaneously supplied to the bag, configuring at the mouth of the bag a bellows similar to the one at its bottom, and finally closing the bag by welding, simultaneously to fixing of the handle thereon, fragmenting the continuous web from which said handle is obtained.

[0010] In order to carry out this process, a packing machine has been provided for, wherein three spools are arranged on top of a frame, one supplying the preformed mesh tubing and the other two ones the webs for obtaining the handles. At the top end area of said frame, a floating wedge is arranged which a preformed mesh tubing accesses through auxiliary and tension control rollers, a pair of traction rollers being placed immediately after said floating wedge, while simultaneously the wedge itself is immobilized by a series of horizontal rollers, perpendicular one to another, which conveniently stabilize it but allowing passage of the preformed mesh tubing, in which interior it is housed. This wedge is suitably shaped to transform the initially flat mesh tubing, into a narrower, preformed mesh tubing with lateral folds, which provide it with a bellows-type structure, for which effect at its lower and narrower end the floating wedge has two deep lateral grooves in the interior of which actuate two idlers that move the mesh towards the bottom of said grooves.

[0011] Immediately afterward said traction rollers are arranged downwardly with regard to the floating wedge and, immediately below them, a welding and cutting mechanism for the bottom of the bag, consisting of two cold clamps, two hot clamps and a cutting blade between them.

[0012] On the cold clamp itself, suction cups to open the next bag are arranged, communicated with a vacuum piston so that at the instant when the cutting of each bag occurs, the bag is open and is placed on a form that belongs to a rotor in which preferably there are four equiangularly distributed forms, so that each one of these forms receives the corresponding bag with an isosceles triangular profile thereof, and turns it into a substantially prismatic-rectangular receptacle which inverts its position when the rotor turns, so that when it occupies the lower end position its mouth is oriented upwardly and is arranged in a condition to receive a product dose through a feeder-doser arranged at the rotor center.

[0013] A side support plate, with a circumference quadrant profile, is arranged beside the rotor, between the second and third stations thereof, i.e. between the horizontal position for the bag and the limiting position in which the bag is left with its mouth oriented upwardly, in order to prevent said bag from decoupling from the corresponding form, the support plate being finished at a case open at least both from the top and from the side corresponding to said support plate, case over which discharge of the product dose occurs, and two cases existing which are assembled over the piston of respective pneumatic cylinders allowing to lower the bag after its filling up and to alternatively move the carriages with the bags towards two bag sewers arranged laterally and symmetrically with regard to the filling area, the parity of which allows to increase the speed of the process.

[0014] Each bag sewer has a feed spool of the plastic strap constituting the handle, which through a pair of pinch rolls introduces its free end inside the bag while at the same time a pair of side pusher plates actuate on said mouth to provide it the same bellows-type structure that it has on its lower and closed end actuating a welding and cutting assembly immediately afterward, that on one hand closes the mouth of the bag and one the other fragments the strap constituting the handle, the bag finally falling on a exit conveyor for its evacuation.

Description of the Drawings

[0015] To complement the description being made and with the object of helping to better understand the features of the invention, according to a preferred example of a practical embodiment thereof, as an integral part of said description a set of drawings is attached hereto in which with an illustrative and non-limiting character the following has been shown:

Figure 1 shows a front elevation schematic view of a machine for packaging fruit and vegetable products made according to the object of the present invention.

Figure 2 shows a profile schematic view of the same machine.

Figure 3 shows a front elevation profile of the floating wedge.

Figures 4, 5 and 6 show respective cross sections of the wedge of the precedent figure, according to section lines A-B, C-D and E-F of said figure.

Figure 7 shows an elevation and profile schematic view of the welding and cutting assembly of the bottom of each unit or bag extracted from the mesh tubing.

Figure 8 shows a side elevation schematic view of one of the forms in the machine rotor, in the position in which said form receives the bag.

Figure 9 shows a schematic view of the precedent figure, in which the form has made the bag to extend.

Figure 10 shows an enlarged detail of the machine at the level of the rotor thereof.

Figure 11 shows a profile of the assembly shown in the precedent figure, in which the finishing distribution carriage has been also included.

Figure 12 shows front elevation and profile schematic view of the mechanisms corresponding to the handle making and bag closing station.

Figure 13 shows a profile schematic view of the gate system for the passage of the fruit towards the distribution rotor.

Figure 14 shows a series of sequences about how the fruit doses reach the rotor core.

Preferred Embodiment of the Invention

[0016] In view of the mentioned figures and especially of figures 1 and 2, it can be seen how in the fruit and vegetable packing machine proposed by the invention a frame (1) participates, over which a turret (2) is assembled, finished by a top head (3) which supports a floating wedge (4) which, especially as can be seen on figure 3, is supported by a plurality of pairs of parallel rollers (5-5'), all of them horizontal and forming two perpendicular groupings among each other; the floating wedge (4) is intended for being housed inside the mesh tubing (6) which continuously comes from a feed spool (7), conveniently guided by means of rollers (8), is dragged by a pair of pinch rolls (9) located at the exit of the floating wedge (4).

[0017] This floating wedge (4) has as its specific object to provide the bag with a bellows-type structure by means of two lateral folds, to which effect the wedge incorporates in its output lower section two deep lateral and coplanar grooves (10), especially noticeable in figure 3, wherein respective idlers (11) of considerable diameter and reduced thickness actuate, so that said idlers (11), located on the outside of the continuous tubing (6), force the latter to withdraw towards the back of the grooves (10), the tubing thereby adopts at the exit of the floating wedge the pretended bellows-type configuration.

[0018] Below the pinch rolls (9) a welding and cutting assembly is arranged, in which two cold clamps (12), two hot clamps (13) and a blade (14) between them participate, so that this assembly causes a transversal welding line for closing the bottom of each bag and its separation from the immediately following bag, closed bag which is left with its mouth oriented downwardly and open by the separation of the cold clamps (12) and especially by the existence on them of openings acting as suction cups, conveniently communicated both between each other and to a vacuum piston, to achieve the triangular profile of the bag (15) shown in figure 8, thereby the bag is deposited on a form (16) which belongs to a assembly of preferably four radial and equiangularly-distributed forms, arranged on a rotor (17), especially as can be seen in the enlarged detail of figure 10, each form having a pair of arms (18) that swing by the effect of respective cylinders (19), which allow to change the bag (15), initially of a triangular profile, into the prismatic-rectangular bag shown in figure 9, change that occurs at the exit of the first station, before the bag is placed horizontally, as can also be seen in figure 10.

[0019] From this second station, the rotor (12) is assisted by a side support plate (20) that prevents the bag (15) from uncoupling from its corresponding form until reaching the third station, in which the bag is left vertically placed with the mouth oriented upwardly, specifically placed over a case (21) open at least both by the top and laterally, so that the bag (15) is left facing the core (22) of the rotor (17), consisting of a compartment that houses a dose of the product (23) to be packaged, product that accesses said compartment as will be seen later on.

[0020] The case (21) is associated with the rod (24) of a cylinder that allows its raising and lowering and which in turn is assembled over a distribution carriage (25) which moves parallely to the exit conveyor (26), as can be seen in said figure 10 and also in figure 11, so that said carriage (25) is capable of making the cases (21) alternatively face the third station of the rotor, the bag filling station, or a pair of lateral bag sewers (27-27'), so that in a maneuver of the carriage (25) a case (21) is placed in conditions to receive a bag for filling thereof, whilst the other one is placed facing a bag sewer (27) to close the filled bag in a prior cycle, whilst the movement of the carriage (25) means that the first case (21) moves the filled bag towards the second bag sewer (27), whilst the already empty carriage facing the first bag sewer goes on to be left facing the filling rotor, at the same time as the bag already filled and with handles, suspended from the bag sewer (27) falls due to gravity on the exit conveyer (26) when it becomes released from the bag sewer.

[0021] Each bag sewer (27) is structured, as can be seen in figure 12, by means of a pair of coplanar, mobile side plates (28) intended for laterally acting and in contrast on the bag (15), to effect a bellows-type folding thereof at the end corresponding to its mouth similar to the one existing at its bottom, a pair of pinch rolls (29) being located over the support of these pushing plates (28) for a plastic strip (30) form which the handle for each bag is going to be obtained, coming from a continuous spool (31) conveniently arranged in the machine frame, a cutting mechanism being located under the pair of pinch rolls (29), consisting in a blade (32) and its corresponding counter blade (33) and underneath them a welding mechanism consisting in a hot clamp (34) that simultaneously effects both closing of the bag and fixing thereon of the handle (35) simultaneously cut from the web (30).

[0022] The fruit (23) is supplied by a feeder-doser, of any conventional type, the core (22) of the rotor (17) preferably having four equiangularly-distributed gates, actuated by means of respective pistons (36) assembled on the rotor itself and receiving the air through the shaft (37) of the rotor itself and through respective valves that are sequentially activated so that, as can be seen in the sequential scheme of figure 14, the dose of product (23) falls in a hopper (38), closed at its bottom by a pusher (39) which, when it withdraws beyond the hopper (38) it leaves open the exit mouth (40), the fruit falling due to gravity into a ducting (41) on which the pusher (39) itself travels, dragging the fruit into the inside of the core (22), at the same time closing the hopper (38).

Claims

1. A process for packing fruit and vegetable products from a preformed mesh-and-straps tubing, characterized in that therein the following operative steps are established:

- Folding the mesh-and-straps tubing to determine therein a bellows-type structure.

- Fragmenting said tubing in portions corresponding to respective bags or packages, with simultaneous closing of each fragment at the end corresponding to the bottom of the bag, which is left oriented upwards.

- Coupling the bag to a form with which the bellows configuration therefrom is mainly eliminated, having it adopt a basically prismatic-rectangular configuration.

- Swinging said bag 180° so that the mouth therefrom is left facing upwards.

- Discharging the product dose in its interior.

- Moving the full bag towards a closing unit where the bag recuperates the bellows-type structure in its sector corresponding to its mouth, receives in its interior the free end of a strip acting as a lifting handle and both the closing by heat welding of the mouth of the bag, with subsequent fixing of the handle, and the fragmenting of the continuous strip from which said handle comes from, occur.

2. Machine for packaging fruit and vegetable products from a preformed mesh-and-straps tubing, according to the process of claim 1, characterized in that on the top turret (3) of a frame (1) a floating wedge (4) is incorporated, supported on rollers (5-5'), which wedge is provided on its lower end with two narrow and deep grooves (10), coplanar and opposite, inside of which respective idlers (11) actuate, which determine the bellows-type folding for the wen tubing (6) from a supply spool (7) conveniently arranged on the frame (1), tubing (6) which is dragged by a pair of traction rollers (9) located immediately after the floating wedge(4).

3. Machine for packing fruit and vegetable products from a preformed mesh-and-straps tubing, according to claim 2, characterized in that immediately below the traction rollers (8) it includes a cutting and welding assembly in which a cold clamp (12), a hot clamp (13) and a cutting blade (14) between them participate, this assembly being located in the vertical that passes by the imaginary shaft of a rotor (17) preferably provided with four radial and equiangularly-distributed forms (16), emerging from a central core (22), sequential receiver of doses of fruit and vegetable products (23) to be packaged, so that each form (16) receives a bag (15) when it adopts the top end position and it moves it to a lower extreme position making it swing 180° so that its mouth is left facing upwards.

4. Machine for packaging fruit and vegetable products from a preformed mesh-and-straps tubing, according to claim 3, characterized in that each form (16) includes a pair of swinging arms (18) assisted by respective cylinders (19), so that said arms (18) converge upwardly at the time of receiving a bag (15), forcing this one to adopt an isosceles triangular profile, and subsequently swing until adopting a parallel position in which the bag (15) adopts a substantially prismatic-rectangular configuration.

5. Machine for packaging fruit and vegetable products from a preformed mesh-and-straps tubing, according to claims 2 and 3, characterized in that a support plate (20) is arranged laterally arranged with regard to the rotor (17), which plate extends between the horizontal position and the lower position of the forms (16) and which acts as a retaining means for the bottom of the bags (15), preventing their uncoupling thereof with regards to the corresponding form, said plate (20) leading into a case (21) open both from the top and laterally, finally receiving the bag at the time of filling thereof.

6. Machine for packaging fruit and vegetable products from a preformed mesh-and-straps tubing, according to claim 5, characterized in that it includes two cases (21) assembled with the ability of vertical movement on a distribution carriage (25), so that in the facing position of each carriage (21) to the filling area of the rotor, the other carriage is left facing one or the other one of the two bag sewers (27-27').

7. Machine for packaging fruit and vegetable products from a preformed mesh-and-straps tubing, according to claims 2 to 6, characterized in that each bag sewer (27-27') incorporates a pair of coplanar pusher plates (28) for giving the bag (15), at the level of its mouth, of a new bellows-type folding, further includes a bag sewer (34) by welding, and above it, a cutting unit (32-33) located immediately below a pair of pinch rolls (29-30) from which the segments (35) comprising the respective bag handles are obtained.

8. Machine for packaging fruit and vegetable products from a preformed mesh-and-straps tubing, according to claims 2 to 7, characterized in that the core (22) of the rotor is provided with four gates, facing the respective forms (16) and actuated by means of respective pistons (36), each gate opening during the step of filling the core (22), when the same is left facing a feed ducting (39) which laterally receives the dose of fruits (23), due to gravity, from a hopper (23), and further constituting the guidance means for a pusher (39) which in a situation of maximum retraction allows falling of the fruit and subsequently it dragging it into the inside of the chamber or core (22) of the rotor (17) while at the same time closing the hopper.

Drawing