Field of the invention

The present invention generally finds application in the field of product packaging machines and particularly relates to a machine for closing flexible containers.

Background art In the field of food packaging, it is known to use containers or bags made of flexible material, such as plastic or paper, which have a neck with an opening designed to allow introduction and/or removal of one or more products, and to be re-closed using a tie, a band or any other rigid or semirigid sheet element.

The latter is wrapped in such a manner as to allow a user to re-open the bag and withdraw products through the opening.

Particularly, it is known to use bands or straps, usually known as clips, generally made of polymer or metal material, which are fed from a coil and cut to size immediately before the closing step, to encircle the bag neck, proximate the opening, and re-close it.

Typically, small to medium-sized retail businesses, such as bakeries or delicatessen stores use bag closing machines having a frame with a station for manual positioning of the bag neck, in which the closing step is carried out.

A housing for a closing band coil is located proximate the station and is unwound in a controlled manner using an intermittently-driven friction disk, to move one portion of predetermined length at a time next to the closing station. The portion designed to encircle the bag neck is cut by a blade which is movable perpendicular to the closing band.

Then, the cut portion is pushed by the blade into the closing station, in which an abutment wall causes it to deform and encircle the bag neck, to close it.

In machines designed for this particular fields, all the movements of the various parts, such as the coil support, the friction disk, the knife and any accessory part, such as the stamping unit for transferring text to the band, are generally driven by pneumatic actuators.

A control unit may be provided for controlling air supply to the various devices, to coordinate their movements. These solutions appear to be markedly disadvantageous, in that they require a special unit for supplying the machine with compressed air in the premises where packaging takes place, which apparently increases the overall costs and introduces restrictions in the installation of the machine. Furthermore, coordination of the movements of the various parts is complex and not always accurate.

Disclosure of the invention The object of the present invention is to obviate the above drawbacks, by providing a machine for closing flexible containers that is highly efficient and relatively cost-effective.

A particular object is to provide a machine for closing flexible containers that is portable and may be installed in any room, without requiring the provision of a compressed air supply unit beforehand. A further object is to provide a machine for closing flexible containers that ensures synchronous movement of its parts using accurate and inexpensive means. These and other objects, as better explained hereinafter, are fulfilled by a machine for closing flexible containers as defined in claim 1 , which comprises a support frame, a plate secured to said frame and having a slot for receiving the neck of one container at a time, a forming station located at the end of said slot for the neck of the container to be placed and closed therein, a cutting station for cutting a portion of the closing band having a predetermined length, feeding means for feeding the band into said cutting station, cutting and shaping means, for cutting and shaping the portion of the band in the cutting station, actuator means for driving the feeding means and the cutting and shaping means.

The machine is characterized in that said actuator means are solely driven by an electric motor.

With this particular configuration, the machine may be located in any room and be operated by simply connecting it to the mains in the room.

Advantageous embodiments of the invention are defined in accordance with the dependent claims. Brief description of the drawings

Further characteristics and advantages of the invention will be more apparent upon reading the detailed description of a preferred, non-exclusive embodiment of a machine for closing flexible containers of the invention, which is described as a non-limiting example with the help of the annexed drawings, in which :

FIG. 1 is a perspective view of a machine according to the invention ; FIG. 2 is a lateral view of the machine of Fig. 1 ;

FIG. 3 is a top view of the machine of Fig. 1 with certain elements being omitted for a clearer view of its interior;

FIG. 4 is a top sectional view of a detail of the machine of Fig. 1 ;

FIG. 5 is a front view of the machine of Fig. 1 ;

FIG. 6 shows a container closing sequence.

Detailed description of a preferred embodiment Referring to the above figures, a machine of the invention, generally designated by numeral 1 , may be used to re-close containers or bags C made of polymeric material, paper or metal material, which have a neck N with an opening A for withdrawing products therefrom. The containers C may be designed to contain products of any type, possibly food, with no particular limitation.

The machine 1 of the invention is portable and can be located in any room having a connection to the mains or any other voltage source.

As shown in Fig. 1 and Fig. 2, the machine 1 comprises a load-bearing frame 2 which can be installed on a floor and has a shaping seat 3, allowing the neck N of the container C to be manually placed and closed therein. The shaping seat 3 is located at the end of a slot 3' formed in the frame 2 to allow the neck N of the container C to be slid into the shaping seat 3.

The frame 2 also has a support 4 for a coil B of a band or any other substantially band-shaped closing sheet element having suitable stiffness and deformability.

Such element may be substantially flat and made from a metal material, such as aluminum, or even a polymeric material, possibly with wire cores extending therethrough to increase its rigidity, while maintaining its deformability. Typically, the closing sheet element E may have a width of a few millimeters, e.g. from 3 mm to 1 0 mm.

Nevertheless, it shall be understood that the materials and sizes of the closing band W are indicated by way of example only and without limitation to the present invention, and that any commercially available closing element may be used therein.

The frame 2 further comprises a substantially horizontal support plate 5 having means 6 thereon for feeding the band E by unwinding the coil B and for guiding a portion P of the sheet element E of predetermined length I to a cutting seta 7 located on the same plate 5, and in which the portion P of the band E to be cut will be substantially vertical.

The feeding means 6 are designed to translate at least one end section of the coil B in a first predetermined direction X substantially parallel to the top surface of the plate 5. The plate 5 is preferably, but not necessarily horizontal.

The machine 1 further comprises cutting and pre-shaping means 9 for cutting and pre-shaping the portion P of the band E.

The cutting and shaping means 9 are designed to operate in a second direction Y, to capture the portion P of the band E contained in the cutting seat 7, cause its separation from the coil B and push it into the closing station 3.

Second shaping means 1 0 are provided in the closing seat 3, which are adapted to deform the cut and pre-shaped portion P and wrap it around the neck N of the container C, to close its opening A.

Both the means 6 for feeding and guiding the band E and the cutting means 9 are driven by actuator means 1 1 that are directly mounted to the frame 2 and impart respective movements to such means.

According to a peculiar feature of the invention, the actuator means 1 1 are solely driven by a motor 1 5 and are designed to be connected to a voltage source 12, schematically shown in Fig. 2, to be solely supplied with voltage.

Advantageously, the actuator means 1 1 are operatively connected to the feeding means 6 and the cutting means 9 through first and second transmission means 1 3 and 14 respectively.

In a preferred, non-exclusive embodiment of the invention, the actuator means 1 1 include an electric motor 1 5 mounted to the frame 2 in any position and having a power supply. Particularly, the motor 1 5 may be designed to be connected to any external voltage source 1 2, such as the mains in the premises in which the machine 1 is located from time to time, a voltage generator, possibly of movable type, or may be also powered by batteries. It shall be understood that the type of electric motor as used in the present invention is in no way limited, and may be either conventional or linear.

In the illustrated configuration, the motor 1 5 has a power drive shaft, not shown, whose output is connected to the feeding means 6 and the cutting means 9 through the first and second transmission means 1 3, 14 respectively. These means 1 3, 14 are designed to convert the rotary motion of the power drive shaft into respective movements of the feeding means 6 and cutting means 9. In a further particularly advantageous aspect of the invention, a kinematic linkage 1 6 is provided, for mutually connecting the first transmission means 1 3 and the second transmission means 14 and to connect them to the electric motor 15, for synchronized drive thereof. Particularly, the kinematic linkage 1 6 is designed to allow coordinated movement of the cutting means 9 and the feeding means 6.

Also, the kinematic linkage 1 6 may be designed to allow at least partially simultaneous movement of the feeding means 6 and the cutting means 9.

Thus, the translational motion of the cutting means 9 in the second direction Y will only occur, at least in the final section of the total travel from the cutting seat 7 to the forming and closing seat 3, when the feeding means 6 have already carried the portion P to be cut into the cutting station 7.

In the illustrated configuration, the feeding and guide means 6 include a pulling element 1 7 which is designed to engage the portion P of the band E and carry it into the cutting station 7. For example, the pulling element 1 7 includes a pair of friction disks 18 and 19 having respective peripheral sliding surfaces which are designed to contact opposite faces of the band E to assist sliding thereof and unwinding of the coil B. The two disks 1 8 and 1 9, which may have any diameter ratio therebetween, are adapted to rotate about first substantially parallel axes of rotation W, Z respectively, which are substantially vertical in the illustrated configuration. Particularly, a first disk 1 8 is a driving disk, and the other 1 9 may be driven and idly or frictionally mounted about its axis Z. The driving disk 1 8 is connected to the actuator means 1 1 , e.g. to the power drive shaft of the motor 1 5, through the first transmission means 1 3.

The latter may include a first transmission element 20 interacting with the power drive shaft of the motor 1 5 through the kinematic linkage 1 6 and is adapted to rotate about a second axis of rotation K, substantially parallel to the first axes of rotation W, Z.

Furthermore, the first transmission means 1 3 include a first mechanism 1 3', e.g. a linkage, such as a crank-slider, cam, crank, or similar mechanism, to transfer the rotary motion of the first transmission element 20 to the driving disk 1 8 and cause unwinding of the coil B.

The cutting means 9 may include an elongate slider 21 , which is designed to slide in a second direction Y above and parallel to the top surface 8 of the support plate 5. Preferably, the first direction X and the second direction Y are substantially orthogonal to each other.

Particularly, the slider 21 is designed to move between a first rearward, inoperative limit position and a second forward limit position, in which it interacts with the portion P of the band E contained in the cutting station 7 to force it into the forming station 3.

The slider 21 has a substantially vertical blade 23 at its free end 22, and is connected at the other end 24 to the actuator means 1 1 through the second transmission means 14.

The kinematic linkage 1 6 may be adjusted for the starting section of the travel of the slider 21 from the first limit position to the cutting seat 7 to be covered at the same time as the band E is unwound, thereby reducing cycle times. The second motion transmission means 14 may include a second transmission element 25 adapted to rotate about a third axis of rotation R which may be, by way of example, substantially parallel to the second axis of rotation K. Furthermore, they include a second mechanism 14', also possibly a linkage, which connects the second transmission element 25 with the end 24 of the slider 21 , to transfer the rotary motion of the motor 1 5 thereto and convert it into a reciprocating translational motion of the slider 21 in the second direction Y.

The transmission elements 20, 25 may consist of friction disks or gear wheels or more complex gearing systems, e.g. bevel gears, according to the direction in which the power drive shaft of the motor 1 5 extends. The kinematic synchronization linkage 1 6 may include an annular connection element 26, such as a drive belt or chain, which partially encircles the peripheral surfaces of the transmission elements 20, 25 to cause coordinated movement thereof. Particularly, one of the two transmission elements 20, 25, e.g. the second 25, may be directly connected with the power drive shaft, possibly through an intervening transmission or gearmotor, not shown, whereas the connection of the other transmission element 25, 20 with the power drive shaft is obtained through the annular connection element 26.

The sizes of the transmission elements 20, 25 and the connection element

26, as well as their relative positions, will allow coordination of the movements of the cutting means 9 and the feeding means 6, according to arrangements known to the skilled person, which will not be described in further detail. As shown in Fig. 4, the second shaping means 1 0 may include a first shaping member 27 located in the cutting seat 7 and designed to impart a substantially U shape to the previously cut portion P of the band E, with the concave side facing towards the shaping seat 3. The latter will in turn accommodate a second shaping element 28 having a substantially vertical abutment surface 29 transverse to the second direction Y with convex transverse ends 30.

The frame 2 may comprise a closing lid 31 , which may be hinged to the support plate 5 or otherwise placed thereon to protect both the cutting means 9 and at least part of the feeding means 6, e.g. the friction disks 1 8 and 1 9. Conversely, the shaping seat 3 is located outside the lid 31 .

Therefore, the latter will have a lateral aperture 32 for receiving the band E and a front aperture 33 for ejecting the blade 23 of the slider 21 and for allowing the cut portion P of the band E to move from the cutting seat 7 to the shaping and closing seat 3.

The frame 2 also comprises a support column 34 for permanent or removable installation thereof on the floor of the room, for easy transportation thereof.

In a particular variant, the machine 1 may also include a stamping station 35 mounted at the side of the plate 5, which has means 36 for delivering a dyeing material, such as an ink or the like, to a transfer element 37 for transferring the dyeing material to the closing band E. The transfer element 37 will pivot about a fourth axis of rotation between a first dyeing material withdrawing position to a second transfer position, in which it contacts a face of the closing band E, to transfer text, e.g. a date, or an image thereto.

The fourth axis of rotation, which may be substantially vertical, may be driven independent of the feeding means 6 and/or the cutting means 9.

Preferably, it is connected to the same actuator means 1 1 , e.g. the same power drive shaft of the common electric motor 1 5 through third motion transmission means, not shown, possibly connected to the first and second motion transmission means 1 3, 14 through the kinematic linkage 1 6.

In operation, in order to close a container C that has been filled with one or more products, once the actuator means 1 1 are simply connected to the voltage source 1 2, the operator shall manually introduce the neck N of the container S into the shaping seat 3.

Now, the actuator means 1 1 are actuated, e.g. by a simple switch or another control, which cause the power drive shaft to rotate and the cutting means 9 and the feeding means 6 to move in synchronism.

In practice, as the portion P of the band E to be cut is pulled in the first direction X to be introduced into the cutting seat 7, the slider 21 is translated in the second direction Y to carry the blade 23 into the cutting seat 7 and contact the portion P.

Thus, the blade 23 cuts the portion P of predetermined length I and continues its travel while pulling it first against the first shaping element 27 and then into the closing seat 7 until it contacts the abutment surface 29 of the second shaping element 28. The U-shaped portion P has a pair of arms that are pushed against respective convex portions 30 of the abutment surface 29 to encircle the neck N of the container C and re-close it. The stamping step, if any, may be carried out before cutting.

The above description clearly shows that the invention fulfills the intended objects and particularly provides a machine for closing flexible containers that is portable and may be used in any room, without requiring the provision of a compressed air supply unit, but only the connection to a voltage source, such as the mains in the room.

The machine of the invention is susceptible of a number of changes and variants, within the inventive concept disclosed in the appended claims. All the details thereof may be replaced by other technically equivalent parts, and the materials may vary depending on different needs, without departure from the scope of the invention.

While the machine has been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.