Patent Description:
Packaging machines are industrial machinery developed in recent years, especially in the food packaging sector. Thanks to the spread of large-scale retail trade, the need to protect foods and increase their shelf life, understood as a conservation period, has grown, as much as possible counteracting chemical, microbiological, physical, structural and sensorial changes which are in any case inevitable over time, in agreement with Parisi's First Law of Food Degradation. Thermo-welding machines are packaging machines for welding reeled films (polypropylene, polyester, or other plastic films) onto pre-formed plastic trays, or onto special molds to give particular shapes. The possibility of creating a vacuum inside the container and introducing inert gases makes them the most used packaging machines in food packaging. The high production capacity is also a distinctive feature of these machines which, thanks to the chain conveyor with alveoli, allow efficient management of the tray advancement.

The chain conveyor is in most cases constrained to a specific type of alveolar shape. The great variability of existing containers, for marketing reasons, makes it necessary to vary the shape in the conveyor chain lines of the thermo-welding machines. In particular in those with chain conveyor with alveoli, changing the alveolar shape is a big problem as it requires the replacement of the entire chain conveyor, unscrewing every single element to be able to replace it. This action not only requires many hours with disruption to production, but puts the operators at risk during the slat changing operations and is potentially dangerous; the risk of damage to the machine due to assembly errors is very high. To date, some solutions have been presented to avoid this problem, and in general inventions related to innovative thermo-welding systems, of which some examples follow.

One example is the object of patent application <CIT>. The invention relates to the technical field of packaging machines, and describes a food packaging machine of the thermo-welding type. The machine consists of a belt conveyor, support frames, an upper roller, storage racks, a lower roller, a side plate, a transmission roller assembly, a pressure roller, a thermo-welding block and a thermo-welding assembly, the conveyor is connected to the conveyor belt, the two support frames are arranged on a frame at the upper end of the conveyor belt, the upper roller is positioned on the two support frames. The two storage racks are arranged on a frame in the lower part of the conveyor belt, and the lower roller is positioned on the two storage racks. According to the thermo-welding-type food packaging machine, when the conveyor belt and the conveyor run, the food on the conveyor can slide onto the films of the lower roller, the upper roller passes through the transmission roller assembly, and then passes through the pressure roller and the thermo-welding block, thereby the lateral edges of the two layers of film are subjected to thermo-welding in the thermo-welding block, under the operation of the pressure roller, the thermo-welded films move together with the conveyor belt, and finally, in the thermo-welding assembly, the films with the food are cut and subjected to thermo-welding.

Another example is the object of patent application <CIT>. The invention relates to a packaging device. The packaging device comprises a welding and cutting station for welding a film on the edge of a tray and cutting said film, characterized in that it comprises a support surface comprising a plurality of housings housing a plurality of molds, said molds being of different dimensions and/or formats to accommodate trays of different dimensions and/or formats, said support surface being drivable to bring one of said molds at said welding and cutting station.

Another example is the object of patent application <CIT>. The invention relates to a rapid thermo-welding machine for food packaging bags.

The rapid thermo-welding device comprises a base, a support plate is fixedly mounted to the upper end of the base, symmetrical limiting blocks are fixedly connected to the front end of the support plate, a dragging disk is rotatably connected to the upper parts of the support plate limiting blocks at the front ends of the support plate, a movable plate is slidingly connected between the limiting blocks, the upper end of the movable plate is fixedly connected with a guide frame extending to the guide disk, a telescopic column is fixedly installed at the front end of the movable plate, a spring rod is fixedly connected to the lower end of the telescopic column, and symmetrical limiting rods are fixedly installed at the upper end of the base. According to the rapid thermo-welding device for food packaging bags, the guide disk rotates to guide the guide frame, so that a thermo-welding plate moves up and down. The thermo-welding plate is moved by the telescopic column, and the pressing rods fix the thermo-welding plate, so as to obtain the effects of rapid thermo-welding, correct adjustment of the thermo-welding time according to the packaging materials, and improvement of the thermo-welding quality of the packaging bag.

Another example is the object of patent application <CIT>. Universal thermoforming mold sets capable of being quickly changed. The invention claims a heating module comprising an upper matrix and a lower matrix. The upper matrix and the lower matrix are fixedly connected to the outlet of the heating equipment through relative heating plates. The mold core is developed independently and is fixed in the groove of the heating module by screws, and can be replaced by unscrewing the screws and extracting it.

The closest prior art to the present invention can be considered <CIT> that discloses a slat exchange system in thermo-welding machines having cells or alveolar cavities, adapted for use on a thermo-welding machine with cells or alveoli, said system comprising: (i) at least one fixed slat part; (ii) at least one removable slat part having one or more shapes/profiles.

The inventions reported so far, purely by way of example and not exhaustively, are representative of the inventive-technological framework available to date.

The object of the present invention is to propose an innovative slat exchange system in thermo-welding machines having cells or alveolar cavities, capable of solving the technical problems linked to wear of the pins, to clamping which may not be perfect (with risk of damage of the machinery or of injury for the operators), as well as long lead times with considerable production stops, typical of the existing solutions for changing slats which involve dismantling the slat itself from the chain conveyor through bolted unions.

Even more advantageously, the system lends itself to being completely automated, thus allowing the slats on the chain conveyor to be changed through a robot and significantly speeding up the format change process with all the advantages deriving therefrom.

According to the present invention, a slat exchange system in thermo-welding machines having cells or alveolar cavities is provided which is capable of allowing the locking and unlocking of slats with alveoli along the chain conveyor, adapted to interchange the shapes in order to be able to weld different container models with the same machine.

The system comprises a slat divided into two parts, a fixed part connected to the chain conveyor with a bolted union, and a removable part on which the alveoli (or shapes) are present. The removable part can be unhooked from the fixed one through a hooking and unhooking mechanism and can be used on both of its sides, thus providing the possibility of using different alveoli on the same removable slat part.

The hooking and unhooking mechanism comprises a pin which inserts inside a symmetric groove made on the side of the removable slat part. The pin has a flat lower part and a slanting upper part, in order to allow locking the removable slat part simply by pressure, and preventing the accidental unhooking thereof. When the removable slat part is inserted by pressure, the pin snaps inside the symmetric groove, hooking it and a contrast bar, positioned on the bottom of the fixed slat part, provides support for the pressure. The pin is connected to a handle and a bar with spring. By moving the handle backwards (away from the slat) the pin then slides along the spring bar, and it is possible to remove the removable slat part. The spring bar can be replaced using magnetic, electromagnetic, hydraulic or other technology so as to have different types of machinery for automating the disassembly process.

The removable slat part is also designed so that it can house multiple modules which can be moved and recombined in order to allow for a greater number of alveoli (shapes) and to generally guarantee greater versatility.

The system comprises a check sensor which analyzes the alignment between the two parts of the slat. When these are misaligned, the thermo-welding machine is locked and a warning is sent. The sensor is also capable of measuring the distance between the edge of the fixed slat part and the end of the alveoli (or shapes). These distances are communicated to the IT system which manages the processes of the thermo-welding machine. In fact, when the thermo-welding machine is started, the IT system receives all the distances corresponding to the processes to be carried out and, if these are different from those measured by the check sensor, the IT management system locks the thermo-welding machine and sends a special warning. In fact, a difference between measurements is indicative of misalignments, or of slats mounted with the wrong set of shapes; in any case, locking the system prevents breakages and malfunctions.

The system thus designed can be easily automated by using a robot capable of unhooking the removable slat part, automatically manipulating the hooking and unhooking mechanism and positioning it in common racks or housing boxes. The robot instead hooks the removable slat part by simply pressing it against the slanting upper part of the pin which then moves back and allows the removable slat part to enter into position in the fixed part.

The release of the removable slat part, whether it is carried out manually by one or more workers, or in an automated manner, can be facilitated by using a profiled stick which is fixed in a position along the chain conveyor of the thermo-welding machine. The profiled stick automatically unlocks the hooking and unhooking mechanism when the slat slides forward; in fact, the handle slides along the profiled edge of the stick and reaches the unlocked position. Thereby the unlocked removable slat parts can be picked up by the robot or by a single operator; the length of the stick obviously determines how many slats are unlocked at the same time.

The advantages offered by the present invention are evident in the light of the description given up to now and will be even clearer thanks to the appended figures and the related detailed description.

The invention will be described hereinafter in at least one preferred embodiment by way of non-limiting example with the aid of the appended figures, in which:.

The present invention will now be illustrated by way of a purely non-limiting or binding example, resorting to the figures which illustrate some embodiments with respect to the present inventive concept.

With reference to <FIG>, <FIG>, <FIG> and <FIG> show general and detailed views of said slat exchange system in thermo-welding machines having cells or alveolar cavities <NUM> according to the present invention. In <FIG> as in the following description, the embodiment of the present invention currently considered the best is illustrated.

Said slat exchange system in thermo-welding machines having cells or alveolar cavities <NUM> adapted to be adopted on a thermo-welding machine having cells or alveolar cavities <NUM> having a chain conveyor <NUM>, a transmission chain <NUM>, an IT management apparatus <NUM>, comprises at least one fixed slat part <NUM> with a contrast bar <NUM>, at least one movable slat part <NUM> with shapes <NUM> and a symmetric groove <NUM>, at least one hooking and unhooking mechanism <NUM> with at least one pin <NUM>, at least one handle <NUM> and at least one bar with spring <NUM>, a check sensor <NUM>, a robot <NUM>, a profiled stick <NUM>.

Specifically, <FIG> shows a perspective view of said thermo-welding machine having cells or alveolar cavities <NUM> with said chain conveyor <NUM>, on which various units of said fixed slat part <NUM> and said removable slat part <NUM> are arranged in series.

<FIG> shows a detail of said fixed slat part <NUM> and said removable slat part <NUM> in the constrained and released configurations, it is in fact possible to observe said removable slat part <NUM> inserted inside or released and shown on the outside of said fixed slat part, and it is possible to observe said hooking and unhooking mechanism <NUM> and said contrast bar <NUM>.

Said hooking and unhooking mechanism <NUM> is shown in detail in <FIG> in the locked and unlocked configuration. In the locked configuration, said pin <NUM> is located inside said symmetric groove <NUM> of said removable slat part <NUM> and said bar with spring <NUM> is in a rest condition. In the unlocked configuration, said pin <NUM> is moved back within the shape of said fixed slat part <NUM>, applying force on said handle <NUM> and said bar with spring <NUM> is in a compressed condition, in this configuration said removable slat part <NUM> is released and can therefore be extracted from said fixed slat part <NUM>.

<FIG> lastly shows a perspective view of the portion of the thermo-welding machine having cells or alveolar cavities <NUM> where said check sensor <NUM>, said robot <NUM>, and two units of said profiled stick <NUM> are installed. The units of said profiled stick rod <NUM> ensure that said handle <NUM> of three units of said hooking and unhooking mechanism <NUM> slide simultaneously and position themselves in the unlocking configuration to subsequently allow said robot <NUM> to move said removable slat part <NUM>.

Claim 1:
A slat exchange system (<NUM>) in thermo-welding machines having cells or alveolar cavities, adapted for use on a thermo-welding machine (<NUM>) with cells or alveoli having a chain conveyor (<NUM>), a transmission chain (<NUM>), and an IT management apparatus (<NUM>), at least one fixed slat part (<NUM>) permanently connected to said chain conveyor (<NUM><NUM>);at least one removable slat part (<NUM>) having one or more shapes/profiles (<NUM>) and adapted to be reversibly hooked to and unhooked from said fixed slat part (<NUM>) in order to be exchanged with another removable slat part (<NUM>) having different shapes/profiles (<NUM>) and/or for maintenance reasons; wherein said removable slat part (<NUM>) is provided with a symmetric groove (<NUM>) arranged in central position within a wall thickness of said removable slat part (<NUM>); said system being characterized in that it comprises: at least one hooking and unhooking mechanism (<NUM>) installed on said fixed slat part (<NUM>), adapted for allowing hooking and unhooking of said removable slat part (<NUM>) in order to promote a swift exchange/replacement of the latter.