Apparatus for automatic packaging of goods in containers such as tubs and the like

Abstract: There is described an apparatus for packaging goods in containers such as tubs and the like, which comprises a support base (4) defining a horizontal operating path on which a plurality of plate-like modular elements (13) are moved, said elements being each provided with through housings in which the containers or tubs (2) to be filled and subsequently closed are engaged. The plate-like modular elements are moved by actuator members (14) disposed along the operating path, said members imparting to the modular elements step-by-step movements of a predetermined amount and independent of the sizes or formats of the tubs being processed. A closure unit (11) can be positioned along the operating path and it carries out application of a sealing film to the previously filled containers. This closure unit comprises a holding body (21) provided with a heating unit (22) and a die-cutting unit (23) housed within the holding body itself which can be disengaged from the support structure by virtue of interconnection means (26) of the bayonet coupling type.

Description: The present invention relates to an apparatus for automatic packaging of goods in containers such as tubs and the like. Preferably the concerned apparatus is intended for packaging of goods such as food items in preformed tubs although obviously the apparatus can be used for packaging of goods or items of any kind in containers of appropriate sizes. It is known that packaging apparatus presently available on the market comprise a support framework intended for housing a kinematic feed mechanism typically consisting of an endless chain which has an upper stretch adapted to horizontally move a plurality of pins or bars that in turn exert a thrust action on a plurality of containers that, in this way, are made movable along a predetermined longitudinal operating path. In more detail, known apparatus involve a longitudinal path along which the containers are set in motion from a supply station, in which the empty tubs are admitted to the operating path, until a discharge station, in which the tubs suitably filled with the processed goods are sent to a storage station. At an intermediate region between the supply station and discharge station, a station for closure of the containers is provided which, through known means, typically carries out the following steps: possible air extraction from the container; possible introduction of a gas mixture into the container, if food items are being processed for which decay in time is wished to be limited to the highest degree; sealing with a plastic film suitably fed at the closure station. It should be noted that, generally, the plastic film is made of a material adapted to be thermally fixed to the tub edge and subsequently to, or simultaneously with this operation, cut along the tub edges by means of a perimetral socket-punch also associated with the closure station. Downstream of the closure station therefore the tubs come out conveniently filled and suitably sealed to be then stowed in a warehouse or sent to consumers. With reference to the chain feed system provided with pins or bars, as presently used in known apparatus, it will be understood that the tub is positioned in a slidable manner over a longitudinal track at which pins or bars are set in motion due to said kinematic chain mechanism. The tub-thrusting bars or pins are disposed mutually spaced apart by a constant pitch so that in the gap between a pin or bar and the subsequent one, one or several tubs may be positioned. It is also known from document US 4 736 568, a machine for sealing cups which comprises a power drive endless conveyor including a series of rigid plates flexibly connected to one another, to enable the conveyor to be trained around end sheaves. Each plate is formed with a counterbore to receive a cup. A sealing station is mounted over the conveyor and comprises a sealing head movable downwardly towards the cup, in order to seal the peripheral portion of a web, advanced step by step beneath the head, to each cup. Another known apparatus, shown in document EP 0 257 186, which is in accordance with the preamble of claim 1, discloses a forming and filling device for cardboard package. The forming and filling device comprises U-shaped cassettes, to receive the cardboard packages, and a pusher system which drives the cassettes along two longitudinal paths running parallel to one another and permits an alternating transfer from one longitudinal path to the adjacent longitudinal path. While the above described apparatus and in particular the above described tub-handling system are widely used, these devices have at all events several drawbacks and their operating aspects are not very satisfactory. In particular, it will be recognized that typically the operators using the above described packaging apparatus are required to package goods, food items for example, in tubs of different sizes or different shapes. This requirement may even occur at relatively short intervals of time so that the operator responsible for the apparatus in question is obliged to intervene on the latter several times in the same working day to adapt the apparatus to transport of tubs having each time different shapes and sizes and more generally different bulkiness. It is apparent that the traditional apparatus briefly described above hardly lend themselves to an easy replacement of the tub formats because the chain feed system with pins is very rigid from this point of view. In fact, it should be noted that physical dismantling of the thrust pins or bars from the handling chains is first of all required, as well as repositioning of same with a new pitch, taking into account the changed sizes of the tub. In addition, also the movement to be imparted to the pins by the kinematic chain mechanism must be adjusted in such a manner that step-by-step advancements of variable amounts will be carried out depending on the real distance that is each time imposed between a thrust element or pin and the subsequent one; in this connection it is pointed out that the advancement movement imparted to the tubs must necessarily be of the step-by-step type to enable, on the one hand, filling of the tubs with the concerned goods and, on the other hand, sealing of the tubs in the stations intended for this purpose. It is apparent that dismantling of a great number of thrust elements or pins which are mechanically connected with the chain-type driving mechanism and adapting advancement of the chain to the new pitch which is each time required involves interventions by the responsible staff which will bring about prolonged stops in the machine service and well apparent drawbacks in terms of economical yield of the apparatus. On the other hand, in order to avoid a drawback of this kind, the only alternative solution is to have the availability of several machines capable of operating simultaneously so that an operator can deal with different tub formats. This however, as can be clearly understood, does not completely solve the problem because, even if different machines are available, it is impossible to meet all types of tub formats or sizes; on the other hand, availability of several apparatus not only involves high purchase and management costs, but sometimes it may be inconvenient in particular in small firms where a limited production and a high operating flexibility is required. In addition to the above drawback, it should be also noted that, due to their own nature, movement chain systems with bars or pins are also unable to ensure a perfect positioning both transversely of the feed direction and along this feed direction because the tub is not conveniently blocked by stop elements, but it is merely pushed at a side or point of its contour. It is apparent that, in particular if the tub has a curvilinear side surface or a non-rectilinear shaping contour, the thrust pins or bars are completely unable to exert an efficient positioning control over the whole perimeter of the tub. Furthermore, the thrust action itself is very localized and is not carried out on the whole perimetral edge or side wall of the tub itself. It is apparent that a weak control of the tub position can sometimes make filling of the tub itself problematic because the goods, in particular if the tub is of small sizes, could not be correctly directed, causing drawbacks such as soiling of the whole apparatus, undesired waste and an imprecise filling of the tub itself. A further negative aspect of the apparatus of known type is given by the in-line arrangement of the whole feed system. In fact, since one or more filling stations are to be arranged (for instance, in the cases in which several food items are to be inserted in a single tub), as well as one or more weight-checking stations to verify whether the amount of the goods introduced into the tub is within the provided 23 ranges, and one or more auxiliary filling stations to carry out completion of the goods-introduction step if the weighing stations signal mistakes, traditional apparatus have a sufficiently wide longitudinal extension that in some cases can hardly adapt itself to the available spaces. On the other hand, it is apparent that the greater the available space in the tub-feed line is, in particular upstream of the closure stations, the greater the number of operations to be carried out and the number of the devices that can be associated with the packaging apparatus: arrangement of unstacking or loading devices can be provided, as well as several metering devices at longitudinally subsequent positions, to carry out introduction of the goods as briefly described, and, in addition, weighing stations, marking or labelling stations and, downstream of the apparatus, a possible automatic unloading station. A further negative aspect present in traditional packaging apparatus is represented by the difficulty in carrying out disengagement of the operating head from the closure station when the tub format is required to be modified. If should be noted in fact that in the operating head of the closure station provision is made for a socket-punch for perimetral die-cutting, a resistor system for carrying out the sealing operations and abutment members for keeping the tubs at an appropriate position. These members necessarily must be replaced each time a variation in the shapes or formats of the tubs to be processed is required. Also provided within the operating head are gas-admission ducts and air-suction ducts that, conventionally, create a system of controlled atmosphere within the tub when food items are housed therein. When this head is to be removed, presently the operators must intervene on a great number of ducts and mechanical coupling systems, which involves a time-consuming manual intervention which will further affect the earning performance of the machine taken as a whole. Under this situation, it is a fundamental object of the present invention to provide an apparatus for automatic packaging of goods in containers having high operating flexibility and which in particular lends itself to be easily made adapted to operate with tubs or containers of different formats without involving difficult interventions by the operators responsible for it. It is a further object of the invention to make available an apparatus capable of housing a plurality of devices (filling, control, loading devices, etc.) close to each other without the machine as a whole involving an excessive longitudinal bulkiness. It is a still further object of the invention to make available an apparatus capable of carrying out a very precise control not only of the feed operations, but also of the longitudinal and side positions of the tub along its operating path, from the empty-tub loading station to the filling station/stations, to the closure station and finally to the unloading station. The foregoing and further objects that will become more apparent in the course of the following description are substantially achieved by an apparatus for automatic packaging of goods in tub-like containers, comprising the features set forth in one or more of the appended claims. Further features and advantages will be best understood from the detailed description of a preferred but not exclusive embodiment of an apparatus for automatic packaging of goods in accordance with the invention. This description will be taken hereinafter with reference to the accompanying drawings, given by way of non-limiting example, in which: Fig. 1 shows a possible preferred embodiment of an apparatus in accordance with the invention, in elevational front view; Fig. 1a is a plan view of the apparatus in Fig. 1, under operating conditions during movement and packaging of the containers by the concerned apparatus; Fig. 1b is a plan view similar to Fig. 1a showing a possible alternative solution of the concerned apparatus, still shown under operating conditions during movement and closure of the containers; Fig. 2 is a plan view of the apparatus shown in Fig. 1; Fig. 3 is an elevational side view of the apparatus shown in Fig. 1; Fig. 4 is a plan view of an embodiment of a modular element intended for being set in motion by the apparatus in Fig. 1 and arranged to house a plurality of containers or tubs; Fig. 5 is a cross-sectional view of the modular element in Fig. 4; Fig. 6 is an enlarged side view of the apparatus in Fig. 1, where the closure unit associated with the apparatus itself is particularly shown; Fig. 7 shows a detail of Fig. 6 seen in cross section relative to the unit intended for carrying out closure of the containers; Fig. 8 is a section taken along a vertical plane of an upper connecting element associated with the closure unit; Fig. 9 is a plan view of the element in Fig. 8; Fig. 10 is an elevation view of the upper connecting element shown in Fig. 8; Fig. 11 is a vertical section relating to a lower connecting element associated with the closure unit shown in Fig. 7; Fig. 12 is a plan view of the lower connecting element referred to in Fig. 11. With reference to the drawings, an apparatus for packaging of goods in containers, such as tubs and the like for example, has been generally identified by reference numeral 1. In particular, the following description will concern an apparatus intended for packaging goods in thermoformed tubs 2 to which a sealing film 3 is subsequently applied, optionally upon removal of air from the tub and insertion of controlled atmosphere. Apparatus 1 comprises a support structure or base 4 arranged to rest on the ground, by means of conventional support feet 5 for example. As shown in the drawings, the support structure or base 4 comprises a lower frame 6, substantially of parallelepiped shape for example, with which said rest feet are associated, and an elongated upper frame 7 on which an operating path is defined for movement of the tubs 2 to be filled and consequently closed, as better specified in the following. Associated with the support structure is handling means 8 (Fig. 2) which is capable of moving the containers along said operating path (see arrows 7) from at least one station 9 for tub feeding to at least one unloading station 10, following a step-by-step travel. It should be noted that the feed station can provide for use of automatic tub loaders or, alternatively, a manual loading of the tubs can be provided. Likewise, at the unloading station, automated or manual unloading systems can be provided. Along the operating path, downstream of the tub feed station, one or more filling stations may be provided for filling the tubs with the goods, as well as checking and weighing stations after which further filling stations for additional introduction of the goods in the tubs can be arranged. Downstream of the filling station and a possible station for goods checking, by weighing for example, a closure unit 11 is then provided which is intended for associating a corresponding sealing element with each tub previously filled with an appropriate amount of goods. In the example herein shown the closure unit is arranged to apply a sealing film 3 to an upper perimetral edge 2a of each tub. Conventionally, the film is fed from reels provided close to the sealing element so that the film can be conveniently disposed over the tubs and then be engaged with them by heat seal, with subsequent perimetral die-cutting for carrying out the border of the sealing film applied to each tub. Still close to the closure unit 11 conventional means for suction of the air possibly present in the tub operates, as well as controlled-atmosphere admission means, if for example food items are to be packaged for which the presence within the package of gas or gas mixtures is required for the purpose of minimizing decay phenomena in the food items themselves. In more detail as regards structure of apparatus 1, it should be noted that the support structure or base (see Fig. 6) defines, at the upper frame 7, at least one guide portion 12 identifying a substantially flat operating path. The handling means 8 operates on a predetermined number of modular elements 13, disposed close to each other, as shown in Figs. 1a and 1b, along the operating path and removably in engagement with the guide portion 12 of the support structure or base 4. Each modular element houses one or more tubs 2. At least one handling member 14a (see Fig. 2 where the handling member consists of a rodless air member) is associated with the support structure and, at each step imposed to the tubs, it acts on a modular element causing a predetermined movement of same equal to said step. The different modular elements 13 are disposed close to each other and are capable of exerting a thrust action on the following modular element, at least over a predetermined length of the operating path; following the thrust exerted by the handling member to a first one of said modular elements (denoted by 13a in Fig. 1a), a corresponding movement of a predetermined number of modular elements following the first one is obtained along the movement direction given to the first modular element itself. Preferably, since the guide portion 12 defines an endless operating path, shaped as a quadrilateral for example (still see Figs. 1a and 1b), several handling members 14a, 14b, 14c, 14d associated with a respective stretch or side of the operating path will be provided. In more detail, as shown in the accompanying figures 1, 1a, 1b, the endless operating path involves a first longitudinal stretch 15a, a second stretch 15b following the first stretch and transverse thereto, a third stretch 15c following the second stretch and transverse thereto and finally a fourth stretch 15d following the third stretch, transverse thereto and joined to the first stretch. In this case therefore a first actuator member 14a will be provided to be operatively associated with the support structure to move the modular elements 13 along the first stretch 15a of the operating path, as well as a second actuator member 14b to move the modular elements along the second stretch 15b of the operating path, a third actuator member 14c to move the modular elements along the third stretch 15c of the operating path and a fourth actuator member 14d to move the modular elements along the fourth stretch 15d of the operating path. The different actuators 14a, 14b, 14c, 14d will be synchronized with each other so as to carry out a step-by-step movement enabling the closure unit to execute application of the film to the upper edge of each tub. The different actuators impose to the modular elements a rectilinear displacement in a predetermined direction which is parallel to the stretch on which each actuator operates, of an amount equal to the extension of the modular element itself in the same direction. Practically, since each modular element has a plate-like shape (Fig. 6) and a rectangular conformation in a plan view, the movement step imparted to the modular elements along the first and third stretches will be equal to the longitudinal extension "1" of the modular elements, whereas the step imparted to the modular elements along the second and fourth stretches will be equal to the transverse extension "t" of the modular elements themselves. In fact, as better shown in Figs. 1a and 1b, the first and third stretches parallel to each other and orthogonal to the second and fourth stretches of the operating path have an extension of a length value which is a multiple of the longitudinal extension "1" of the modular elements. Likewise, the second and fourth stretches have an extension equal to a multiple of the transverse extension "t" of each modular element. Advantageously, the modular elements slidably move on the guide portion 12; more specifically, said guide portion comprises opposite elements or rails 16 on which the opposite side edges of each of said modular elements slide in rest relationship. To facilitate sliding, the opposite elements or rails of the guide portion will be made of, or coated with antifriction material such as Teflon or another appropriate material. As briefly discussed, each modular element 13 comprises a substantially plate-like main body 17 and one or more through housings 30 in which containers or tubs can be engaged; each of said through housings seen in plan view will therefore have a shape matching that of the containers or tubs to be housed therein. During movement along the operating path, each modular element constantly has two opposite perimetral edges slidably resting on the guide track and at least one edge close to said opposite edges and transverse to the feed direction along the operating path, which is adapted to act on the modular element in thrust relationship. Practically along each stretch (15a, for example) of the operating path the respective actuator 14a acts in thrust relationship on the modular element 13a which is most upstream with respect to the feed direction "f"; by acting in thrust relationship on this modular element, it will be obtained the consequent movement of all modular elements following that on which the actuator acts and present on the stretch concerned with the actuator itself. Obviously, in order to achieve the above movement, the stretch on which the actuator is intervening must not be completely occupied by modular elements. More specifically, the operating path is divided into a plurality of stations "s" following each other, each station being set to house a single modular element. It will be recognized that the number of stations "s" and consequently the sizes of each stretch as well as of all the operating paths could be of any magnitude depending on requirements. It will be possible to select the direction of movement too, without departing from the scope of the invention. In the instance shown in Figs. 1a or 1b each station "s" is exactly shaped as a modular element; at such stations "s" the different modular elements can be positioned in succession during their step-by-step movement (see Figs. 1a. 1b). In order to enable the sequential displacement of the different modular elements along the operating path, at least one of the stations into which the operating path is divided must be free: only in this way in fact, intervention of the actuator member or members intended for movement of the modular elements will involve sequential displacement of the modular elements themselves so as to occupy this free station and consequently free another station. Since preferably, as briefly discussed above, the operating path is of quadrilateral shape and in particular has a rectangular conformation, the free station is constantly located at an angled region of the operating path. This is due to the fact that each actuator only intervenes on a respective stretch or side of the operating path so that it can exert a displacement along a direction parallel to this stretch only of the modular elements present therein; in this way, when an actuator intervenes on a predetermined stretch moving modular elements interlocked thereto, the guides 16 of the following stretch substantially act as end-of-stroke limits causing a precise positioning of the different modular elements. It should be noted that preferably apparatus 1 involves that two stations be constantly free, which stations can be sequentially occupied by said modular elements; this enables a greater automation of the step-by-step movements; these free stations are disposed, under operating conditions of the apparatus, at respective opposite angled regions of the operating path. Practically, as shown in Fig. 1a for example (as one can see, Fig. 1b is similar to Fig. 1a except for the movement direction of the modular elements along the operating path which is reversed, as well as the location of the loading station of the empty tubs and the unloading station of the filled and closed tubs, which are positioned in a different manner relative to Fig. 1a) the tubs are loaded manually in a predetermined loading station 9 of said station "s" and moved to the right along the third stretch 15 where one or more stations for introduction of the goods operate, as far as a weighing station is reached possibly followed by a further station for additional filling or dosing of the goods to be introduced into the tubs. Afterwards, the tubs through the fourth stretch 15d come back to the first stretch 15a of the operating path moving forward to the left until the closure unit 11 is reached where application of the sealing film to the tubs takes place after previous elimination of air and controlled-atmosphere introduction, if necessary. Subsequently, the tubs still moving forward along the first stretch reach a station "s", in this case disposed in the angled region between the first and second stretches of the operating path where an extractor device 18 (Fig. 2) operates and carries out disengagement of the different containers or tubs from the respective housings provided in each modular element. The extractor device comprises a vertical actuator member 18a and an operating portion 18b associated at the top with the actuator member and adapted to act on a lower portion or bottom of each container to cause lifting and extraction of same from the housings defined in the modular element 13 concerned with extraction. For instance, the operating portion of the extractor device will be provided with projections the shape of which matches that of the housings present in the modular element so that said projections can be fitted in the latter from below and cause the necessary lifting of the tubs. Subsequently an auxiliary handling member 19, included in the extractor device too, moves each container vertically extracted from the respective housing 30 in a direction parallel to the lying plane of the modular element until it brings it to an unloading station 10 provided close to the operating path. The auxiliary handling member 19 can be made up of a single bar that, with reference to Fig. 2, is moved by a respective actuator member 20 from right to left causing a consequent movement of the tubs from the modular element concerned with extraction to the unloading station 10. Alternatively, the extractor device 18 may consist of a device provided with suction cups and acting on an upper side of each container or tub, picking it up. In this case too the extractor device 18 will be able to move the tubs from their housings until they reach one or more unloading regions. We are now going to describe in detail the step-by-step movement procedure of the tubs when two free stations (see Fig. 1a again) are provided. In this case the tubs are moved along the first stretch 15a by the first actuator 14a intervening in such a manner that the modular element present at the first angled region (between the fourth and first stretches) is moved towards the immediately following station; in this way the modular element present on the first stretch and which is the one most downstream relative to the movement direction along the operating path will act in abutment against the guide 16 of the second stretch 15b of the operating path preventing any further movement of the plurality of modular elements (in this case four) present on the first stretch and ensuring a perfect positioning of these elements that therefore are submitted to a one-step movement exactly corresponding to the longitudinal extension "1" of each modular element along the extension direction of the first stretch. Simultaneously with the above shifting, the third actuator 14c operating at the third stretch 15c carries out a movement of the set of modular elements following each other and present on the third stretch itself so as to bring them to the condition shown in Fig. 1a; under this condition one can see that in the angled regions between the second and third stretches and between the fourth and first stretches free stations are defined, i.e. stations where there is no modular element. Subsequently, the second and fourth actuators 14b, 14d will intervene and, by moving the modular elements present on the second and fourth stretches respectively along the directions defined by the latter, they will bring a modular element to occupy said free stations. Following this movement, free stations will be defined at the angled regions provided between the first and second stretches and the third and fourth stretches of the operating path. At this point the first and third actuators will intervene again to repeat the cycle briefly described above, carrying out step-by-step displacements of the modular elements and the tubs housed therein along the operating path. The structure of the closure unit 11 will be now described in detail (see Figs. 6 and 7). It comprises a housing or holding body 21 within which means is housed for carrying out application of said sealing element to each container. Practically, the holding body 21 is formed of a box-shaped element open at the bottom and capable of sequentially cooperating with each of the modular elements 13 that, during the operating process, reach the closure unit one after the other. In more detail, the means for applying the sealing element, where the latter consists of a heat-adhesive film for example, comprises a heating unit 22 capable of carry out heat-seal of the upper edges of the containers with said heat-sealable film. The application means preferably also comprises a die-cutting unit or socket-punch 23 to carry out the border of the heat-sealed film. Both the cutting unit and heating unit can be moved up and down, close to and away from the modular element 13 present at the closure unit. More specifically, once the concerned modular element has been positioned at the closure unit, the heating unit 22 is moved close to the modular element and therefore to the upper edges of the tubs or containers, so as to heat-seal the latter to the film operatively interposed between said heating unit and the modular element. Subsequently to, or simultaneously with lowering of the heating unit 22 movement of the cutting unit 23 takes place as well, and the border of the heat-sealed film is formed as said. In the embodiment illustrated both the heating unit and the cutting unit or socket-punch are operatively associated with a support member 24 also located inside the holding body and movable up and down upon the action of an actuator member 25 operatively interposed between the closure unit 11 and the support structure 4 of apparatus 1. Advantageously provided between the actuator member 25 and the support structure 4 is removable-interconnection means 26 enabling disengagement of the holding body 21 and the cutting and heating units 22, 23 contained therein if modification of the tub pattern on which closure is to be done is wished. In more detail, the removable-interconnection means comprises a lower half 27 associated with the holding body and an upper half 28 associated with the actuator member 25; the upper and lower halves are coupled with each other by bayonet coupling or the like. As viewed from Fig. 7, the lower half of the interconnection means has a guide shank 29 slidably passing through an upper wall of the holding body 21 and linked at the end to the support member 24, which consists of a plate for example, which is active by thrust on the cutting unit and the heating unit 22 and 23. The lower half also comprises a glass-shaped portion 31 integral with shank 29, extending on top of said guide shank and arranged to receive said upper half of the interconnection means. The glass-shaped portion 31 seen in detail (see Figs. 11 and 12) has an access edge 32 defining at least one undercut 33 and such shaped that it exhibits radial notches 34 to enable insertion of corresponding radially projecting portions 35 provided in the upper half (Figs. 8, 9 and 10). Also provided is retaining means preventing mutual rotation of said upper half and lower half once these halves are conveniently coupled with each other. It should be noted that the holding body 21 at a lower edge 21a thereof facing the modular element present at the sealing element, has a seal 21b which is necessary in case of possible suction operations and gas introduction. In fact, it is pointed out that air-suction ducts or ducts for introduction of gas or gas mixtures useful to create a controlled atmosphere if food items are to be packaged in the tubs, can be connected with the holding body. Also advantageously connected with the holding body is an electric connector, a multipolar connector for example, for power supply of said heating unit and possible other members electrically operated and not described in detail because they are not of importance with reference to the present invention. It should be finally understood that, due to the configuration of the operating path, also a unit for automatic application of lids may be provided downstream of the closure unit, which lids are intended to be coupled by restrained fitting with the edges of the corresponding containers previously filled and provided with a sealing film. The lid applicator may for example comprise an automatic lid unstacker and one or more pressure devices active on the lids conveniently positioned at the upper perimetral edge of each container. In order to enable coupling between a container and a lid, obviously the modular elements will be provided with appropriate recesses extending at a radially outer position relative to each container-holding housing. The invention achieves important advantages. First of all, it should be noted that due to the structure of the modular elements and the closure unit, apparatus 1 can be readily adapted to any type of tub format to be packaged, i.e. without any problems in terms of prolonged machine stops or difficulties in dismantling parts thereof due to technically unskilled staff. In fact, since each modular element is defined by a plate-like body of sizes adapted to contemplate all possible tub formats and since the pitch imposed to the modular elements is given by the sizes of each modular element itself, independently of the tub formats being processed, the apparatus can always operate at a constant pitch without requiring the movement systems of the modular elements themselves to be modified. Also to be noted is the fact that due to the particular shape and structure of the modular elements, each tub is perfectly controlled as to its position both along the feed direction and transversely thereto. In fact, a perfect control of the exact tub position can ensure high production rates in terms of speed of the movement sequences and accuracy during the filling and checking steps. Also advantageous is the loop-shaped configuration of the operating path in accordance with the present invention enabling achievement of reduced longitudinal sizes while ensuring placement, along the operating path perimeter, of several stations for tub filling and/or checking, as well as devices for automatically carrying out the operations of loading empty tubs and unloading filled and closed tubs. Practically apparatus 1, due to its features, is operatively very flexible and also capable of meeting the requirements of small firms that, in their daily work, must ensure packaging of tubs of different formats without substantially reducing their production rates even when they use a single packaging apparatus. Finally, also advantageous is the plate-like shape of the modular elements that, in this way, conveniently cooperate with the holding body and the heating and cutting units provided in the closure unit so as to obtain an efficient, accurate and quick application of the sealing film to each container.

Claims: An apparatus for packaging goods into tub-like containers, comprising: a support structure (4) arranged to rest on the ground and presenting, at the upper part (7) thereof, a guide portion (12) defining an operating path, which path preferably has a horizontal lying plane; a predetermined number of modular elements (13) engaging at least one of said containers (2) and moving step-by-step along said guide portion (12); said modular elements (13) being disposed close to each other along the operating path and being removably in engagement with the support structure (4), each of said modular elements (13) having a substantially rectangular shape seen in plan view and having two opposite perimetral edges and at least one edge transverse to said two opposite edges and intended to act by thrust on an adjacent modular element (13), at least over a predetermined length of said operating path; handling means (8) comprising at least one handling member (14a, 14b, 14c, 14d) associated with the support structure (4) as well, which member (14a, 14b, 14c, 14d), at each step imposed to the modular elements (13), acts by exerting a predetermined movement on a first one of said modular elements (13), to move a predetermined number of containers (2) along said operating path from at least one feed station (9) to at least one unloading station (10) following the step-by-step motion; a closure unit (11), associated with the support structure (4) at a predetermined region of the operating path; characterized in that said closure unit (11) is arranged to carry out engagement between a corresponding sealing element (3) and each container (2) previously filled with a predetermined amount of at least one type of goods, in that said modular elements are plate-like elements (13) presenting one or more through housings (30), in which said containers (2) can be engaged, and in that said guide portion (12) comprises opposite rails (16) on which opposite side edges of each of said modular elements (13) slidably rest. An apparatus as claimed in claim 1, characterized in that at least one handling member (14) imposes to the modular elements (13) a rectilinear displacement in a predetermined direction of an amount equal to the extension of the modular element (13) itself in said direction. An apparatus as claimed in anyone of the preceding claims, characterized in that a distance between axes corresponding to, or being a multiple of the movement pitch imposed to each of the modular elements (13) by the handling member (14) is provided between each modular element (13) and the subsequently adjacent modular element (13), said pitch being of a predetermined amount and independent of the sizes or shapes of said containers (2). An apparatus as claimed in claim 1, characterized in that said guide portion (12) defines an endless or loop-like operating path. An apparatus as claimed in claim 1, characterized in that said through housings (30) seen in plan view have a shape matching that of the containers or tubs (2) to be housed therein, said plate-like body (17), still in plan view, having constant sizes independent of the shape and sizes of said containers (2). An apparatus as claimed in claim 4, characterized in that said guide portion (12) defines an endless operating path preferably of quadrilateral conformation and more preferably of rectangular shape, said operating path comprising a first stretch (15a), a second stretch (15b) following the first stretch (15a) and transverse thereto, a third stretch (15c) following the second stretch (15b) and transverse thereto and a fourth stretch (15d) following the third stretch (15c) and transverse thereto. An apparatus as claimed in claim 6, characterized in that said handling means comprises: a first actuator member (14a) for moving the modular elements (13) along the first stretch (15a) of the operating path; a second actuator (14b) for moving the modular elements (13) along the second stretch (15b) of the operating path; a third actuator (14c) for moving the modular elements (13) along the third stretch (15d) of the operating path and a fourth actuator (14d) to move the modular elements (13) along the fourth stretch (15d) of the operating path. An apparatus as claimed in anyone of the preceding claims, characterized in that said operating path is divided into a plurality of stations (s) following each other, in each of said stations (s) the modular elements (13) can be positioned during their step-by-step movement, at least one of said stations (s) been free, so as to enable sequential displacement of the different modular elements (13). An apparatus as claimed in claim 8, characterized in that said free station (s) is disposed at an angled region of the operating path. An apparatus as claimed in claim 9, characterized in that it comprises two free stations (s) that can be sequentially occupied by said modular elements (13), said free stations (s) being disposed, under operating conditions of the apparatus, at respective angled regions of the operating path. An apparatus as claimed in claim 10, characterized in that said first (14a), second (14b), third (14c) and fourth (14d) actuator members move said modular elements (13) sequentially and step-by-step along said first (15a), second (15b), third (15c) and fourth (15d) stretches respectively of the operating path, so that said free stations (s) are constantly at opposite angles of the operating path itself. An apparatus as claimed in anyone of the preceding claims, characterized in that it comprises an extractor device (18) operating at said unloading station (10) or close thereto to disengage said containers or tubs (2) from the respective housings (30) provided on each modular element (13). An apparatus as claimed in claim 12, characterized in that said extractor device (18) comprises a vertical actuator member (18a) and an operating portion (18b) associated, at the upper part thereof, with the vertical actuator member (18a) and intended to act on a lower portion of each container (2) to cause an upward movement of same, said extractor device (18) also comprising an auxiliary handling member (19) to move each container (2), vertically extracted from the respective housing (30) provided on the modular element (13), in a direction parallel to the lying plane of the modular element (13) itself to the unloading station (10). An apparatus as claimed in anyone of the preceding claims, characterized in that said closure unit (11) comprises a holding body (21) inside which means for carrying out application of said sealing element (3) to each container (2) is housed, said holding body (21) sequentially cooperating with each of the modular elements (13). An apparatus as claimed in claim 14, characterized in that said application means comprises: a heating unit (22), to carry out heat-sealing to the upper edges of said containers (2) of a heat-sealable film (3) fed close to said closure unit (11), and a die-cutting unit or socket-punch (23), to carry out the border of said heat-sealed film (3), said cutting unit (23) and heating unit (22) being movable up and down close to and away from the modular element (13) present at the closure unit (11) for applying the film (3) to each container (2). An apparatus as claimed in claim 15, characterized in that it comprises a further actuator member (25) active on said heating unit (22) and cutting unit (23) to move them both in an up-and-down trajectory, as well as removable-interconnection means (26) operatively connected between the actuator member (25) and said heating (22) and cutting unit (23). An apparatus as claimed in claim 16, characterized in that said removable-interconnection means (26) comprises a lower half (27) associated with said holding body (21) and an upper half (28) integral with said actuator member (25), said upper half (28) being fitted by bayonet coupling or the like in said lower half (27). An apparatus as claimed in claim 17, characterized in that said lower half (27) has a guide shank (29) slidably passing through an upper wall of said holding body (21) and linked at its end with a support member (24) exerting a thrust action on said cutting unit (23) and heating unit (22). An apparatus as claimed in claim 18, characterized in that said lower half (27) comprises a glass-shaped portion (31), arranged to receive said upper half (28) and having an access edge (32) defining at least one undercut (33), said edge (32) having radial notches (34) for insertion of radially projecting corresponding portions (35) provided on said upper half (28), retaining means for preventing mutual rotation between said upper (28) and lower (27) halves being active once said halves (27, 28) have been conveniently coupled with each other. An apparatus as claimed in anyone of the preceding claims, characterized in that it comprises a unit for lid application, disposed downstream of the closure unit (11) and adapted to couple a respective lid with each container or tub (2) by restrained fitting.

Inventors: GOBBI BRUNO, GOBBI, BRUNO
Applicants: SIATE SOLUZIONI IND APPLIC TEC, SIATE-SOLUZIONI INDUSTRIALI APPLICAZIONI TECNOLOGIE ELETTROMECCANICHE S.R.L.
Application year: 2000
Main classification: B65B43
IPC codes: B65B43, B65B7, B65B59