FIELD OF THE INVENTION

The present invention relates to the technical field of filling valve bags with powder or granulated products, in particular cement for cement industry, building materials, fertilizers and chemicals products. More in detail, the present invention refers to a bag applicator for an“stationary” packer assembly, i.e. a particular packer assembly comprising a plurality of stationary filling nozzles. The present invention moreover refers to a stationary packer assembly comprising this bag applicator and a method for operating this bag applicator.

DESCRIPTION OF PRIOR ART

In the cement industry are used particular machines called packer assemblies. In particular, a packer assembly is an automatic machine configured for manipulating and filling valve bags. A valve bag is a bag, i.e. a rectangular shaped tube of paper plies or plastic, having a rear face and a front face (where usually an indication of the content is provided) wherein each face is defined by two opposite long sides, two opposite short sides and two opposite ends closed by glue or a sewing. Since the empty valve bags are stored in pressed stacks, it is immediately clear which side is the long side. In a valve bag, a corner between a long side and a short side is provided with a valve in form of open folded edge portions of the bag itself. In view of the above configuration, when the bag is in a pressed condition (i.e. face to face pressed), the valve is considered as closed even if the folded edge portions of the opposite faces are not physically bounded to each other. Since the valve bags are fed to the packer assembly in this pressed condition, before the filling operations it is important to preliminary open the valve. This preliminary opening step is performed by a device called valve opening device. Usually the valve opening device is provided by a spreading device configured for spreading an empty or pressed bag at the valve in order to move the valve from the closed configuration foregoing described to an open configuration. In the open configuration, the folded edge portions of the valve (originally one resting on the other in pressed configuration) are physically spaced each other to define an opening substantially rhombus-shaped. Starting from the above general definition of the valve bag and the valve opening device, a bag applicator of a stationary packer assembly comprises: a bag feeding device comprising a supporting plane configured for receiving a valve bag having the valve in a closed configuration; a valve opening device configured for picking up a bag from the supporting plane for opening the valve of a valve bag and for keeping this valve in the open configuration; a bag applicator device configured for picking up the valve bag from the valve opening device with valve in the open configuration, for travelling with this valve bag from the valve opening device to a filling nozzles of the stationary packer assembly by keeping the valve in the open configuration and for releasing the bag at the filling nozzle with the nozzle at least partially inserted into the valve in the open configuration.

In case of the valve opening device is fed by a stack of valve bags, the valve opening device is also configured for picking up a single bag from the stack before opening the valve.

Upstream the feeding device the packer assembly may also comprise a bag storage configured for being supplied with a plurality of stacks of valve bags or with a plurality of single valve bags and for feeding the bags to the feeding device.

Downstream the filling nozzles the packer assembly may comprise a delivery device, for instance a belt, configured for receiving the filled bag and for moving these filled bags away from the packer assembly.

According to the prior art, the valve opening device comprises two suction devices configured for acting on two opposite portions of a bag, namely the valve portion and the opposite closed end. These suction devices, or at least one of them, are configured for preliminary coupling with the bag and for lifting (just few mm) this bag from the relative stack. In this condition, the suction device acting on the valve is configured for performing a relative movement with respect to the other suction device. Due to this movement the bag is spread and the valve consequently open. According to the prior art, the bag applicator device is realized in form of a moving arm provided at its free end with a clamping device configured for picking up the valve bag from the valve opening device and for releasing the bag at a filling nozzle. The movement from the valve opening device to the filling nozzles and vice-versa may be defined as a travelling movement parallel to the disposition of the filling nozzles one beside the other. In order to avoid any impact between the moving arm and the filling nozzles, the linear movement is performed by keeping the arm at a certain distance from the filling nozzles. Once reached a filling nozzle the arm is configured for stopping your its linear or travelling movement and for performing an approaching movement towards the nozzle. Once released the bag at the filling nozzle, the arm is configured for moving away from the nozzle (by a movement opposite to the above approaching movement) in order to reach again the safe distance from the nozzles. At the valve opening device the arm is configured for performing similar movements involved at the filling nozzle, i.e. an approaching movement for reaching the bag kept open by the valve opening device and an away movement for reaching a safe distance from the nozzles in view of the coming linear/travelling movement. Therefore, a working cycle of the above described bag applicator arm may be resumed in the following steps: clamping the open bag at the valve opening device; performing an away movement (for instance an arm rotation (about 60° CCW)) to avoid bag interference during the next linear movement or travelling to the filling nozzles; performing a linear/travelling movement from the valve opening device to a filling nozzle; performing an approaching movement to the filling nozzle (for instance an arm rotation (about 60° CW)); performing an away movement from filling nozzle (for instance an arm rotation (about 60° CCW)); performing a linear movement from the filling nozzle to the valve opening device; performing an approaching movement to the valve opening device for reaching an open bag kept open by the valve opening device (for instance an arm rotation (about 60° CW)).

Therefore, today seven steps in succession are needed, wherein each step requires time form to an entire time cycle. Unfortunately, this arm time cycle represents a limit for the packer hourly capacity. For instance, an inline packer having four filling stations wherein each filling station has a capacity from 350 to 400 bags/h could reach theoretic capacity of 1400 to 1600 bags/h for the entire packer. However, the actual capacity is limited to 1200 bags/ due to the long arm time cycle above explained.

DISCLOSURE OF THE INVENTION

Accordingly, a primary object of the present invention is to provide a bag applicator assembly for a stationary packer assembly suitable for overcoming the problem foregoing described of the prior art. In particular, the main purpose of the present invention is to provide a stationary packer assembly having a higher capacity, i.e. a capacity limited by the capacity of the filling operations and not by the bag applicator device time cycle.

According to a first aspect of the invention, a bag applicator assembly for a stationary packer assembly for filling valve bags is provided. In particular, with the terms“valve bag” we refer to a bag in form of a rectangular shaped tube having a front and a rear face and wherein each face is defined by two opposite long sides, two opposite short sides and two opposite ends closed by glue or a sewing. A valve is provided at a corner between a long side and a short side in form of folded edge portions of the bag itself. By spreading the bag, the valve is movable from a closed to an open configuration wherein in the open configuration the edge portions of the opposite face are separated. The valve bags used in the present invention are the valve bags currently available.

As known, a bag applicator assembly for a stationary packer assembly comprises: a feeding device comprising a supporting plane (preferably movable/adjustable in vertical direction) configured for receiving a valve bag or a stack of valve bags having the valve in a closed configuration (i.e. the bags or the stacks of bag are fed having a face parallel to the supporting plane);

a valve opening device configured for cyclically moving between a first configuration wherein it picks up a valve bag from the supporting plane and a second configuration wherein the valve has been open and kept in the open configuration.

a bag applicator device configured for picking up the valve bag from the valve opening device, for travelling from the valve opening device to a filling nozzle of the packer assembly in a travelling configuration for avoiding bag interference with the filling nozzles and for releasing the bag at the filling nozzle.

Starting from this well-known structure, according the main aspect of the invention in the second configuration the valve opening device is in a position so that the bag applicator device can pick up the valve bag in the travelling configuration without any additional approaching movement required.

Preferably, the valve opening device is configured for cyclically moving from a first or lower position and a second or raised position with respect to the supporting plane wherein in the lower position the valve opening device is in the first configuration and in the raised position the valve opening device is in the second configuration. The purpose of this raised configuration is clear with respect to another component of the bag applicator assembly, i.e. the bag applicator device configured for moving the bags from the valve opening device to the filling nozzles. Advantageously the raised movement of the valve opening device allows to reduce the working cycle of the bag applicator because once arrived at the valve opening device the bag applicator can pick up an open bag without any delay and any additional approaching movement required. According to different embodiments, the valve opening device can be configured for reaching the second configuration before the raising movement, during the raising movement or after the raising movement provided that when the bag applicator device arrives at the valve opening device the bag has to be ready for being picking up.

The valve opening device and the actuation of the raising movement may be realized in many different ways. In the following descriptions of the drawings a solution will be described wherein the known opening device has been housed in a tilting supporting frame moving with respect to the supporting plane.

As mentioned above, the present invention refers also to a packer assembly comprising a bag applicator assembly as foregoing mentioned. Moreover, as known, the inline packer comprises:

- a plurality of stationary filling nozzles, preferably arranged one beside the other along a liner/straight direction, wherein each filling nozzle configured for entering the valve in the open configuration and for delivery a powdery material inside the bag.

Due to the presence of the bag applicator assembly of the present invention, in the raised position the valve opening device is in a position so that when the bag applicator device enters the opening valve station it can pick up the valve bag directly in the travelling configuration without any additional approaching movement required.

The bag applicator device may be realized in different ways. In the following description of the drawings an embodiment will be described wherein the bag applicator device is a tilting arm running along a guide (preferably a linear guide) and provided at a free and with a clamping device.

The present invention refers also to a method for operating the foregoing described bag applicator assembly. In particular, the main feature of this method is controlling the raising movement of the valve opening device so that when the bag applicator device reaches the valve opening device the bag can be picked up by the bag applicator device without any delay and any additional movement required from the travelling condition. With reference to the prior art operating steps mentioned in pages 5 and 6, according to the present invention the steps labelled with the number 2 and 7 are no more necessary.

In the present context a number of terms are used in a manner being ordinary to the skilled person. Some of these terms are detailed below:

Travelling is preferably used to denote a movement of the valve bag from one position to another.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention as claimed. Other advantages and features of the invention will be apparent from the following description, drawings and claims.

The features of the invention believed to be novel are set forth with particularity in the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes an exemplary embodiment of the invention, taken in conjunction with the accompanying drawings, in which:

Figures 1 a and 1 b are schematic views of a kind of valve bag respectively in empty and in filled configuration;

Figure 2 is a schematic view of an inline packer according to the invention;

Figures 3 and 4 are schematic views of the inline packer of figure 2 in two different configurations;

Figures 5-7 are schematic views of a valve opening device according to the present invention;

Figure 8 is a schematic view of the inline packer according to the present invention, and

Figure 9 is a schematic view of the inline bag applicator according to the present invention

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In cooperation with attached drawings, the technical contents and detailed description of the present invention are described thereinafter according to preferred embodiments, being not used to limit its executing scope. Any equivalent variation and modification made according to appended claims is all covered by the claims claimed by the present invention.

Reference will now be made to the drawings to describe the present invention in detail.

Reference is made to Figures 1 a and 1 b, which are schematic views of a kind of valve bag for the present invention, respectively in empty and in filled configuration. As known, this valve bag 3 is a bag in form of a rectangular shaped tube having a front face 17 and a rear face and wherein each face is defined by two opposite long sides 18, two opposite short sides 19 defining two opposite ends closed by glue or a sewing. A valve 4 is provided at a corner between a long side 18 and a short side 19 in form of folded edge portions of the bag itself. By spreading the bag, the valve 4 is movable between a closed and an open configuration wherein in the open configuration the edge portions of the opposite face are separated for forming an opening connecting the interior space of the bag itself.

Reference is made to figure 2 which is a schematic view of an inline packer assembly 2 according to the present invention for filling a bag 3 of figure 1 a. This inline packer assembly 2 is provided with a stationary packer and comprises: an opening valve station 1 provided with a valve opening device 6;

a bag applicator device 13;

a plurality of filling stations 1 1 arranged one beside the other along a liner/straight direction wherein each filling station 1 1 is provided with a filling nozzle 12.

The disclosed opening valve station 1 is defined by a supporting plane 5 of a feeding device configured for receiving a valve bag 3 or a stack of bags having the valve 4 in a closed configuration as represented. The supporting plane 5 may be movable/adjustable in vertical direction so that the bas to the picked up is always in flush with the valve opening device. The valve opening device 6 is configured for cyclically moving between a first configuration and a second configuration. In the first configuration the valve opening device 6 is able for picking up the valve bag 3 from the supporting plane 5 whereas in the second configuration the valve opening device 6 is able for opening the valve 4 and keeping the valve 4 the open configuration.

Once open, the bag is picked up by a bag applicator device 13 in the form of a tilting arm 14. This tilting arm 14 is at one side connected to a linear guide 15 running along the filling stations 1 1 and at the opposite side is provided with a camping device 16 configured for picking up the valve bag 3 from the valve opening device 1 with the valve 4 in the open configuration. As known, this clamping device is suitable for bringing the open bag, for keeping the valve open during the movement along the guide 15 and for releasing the bag at a filling station. During the travelling movement along the guide 15 between the opening valve station 1 and the filling stations 1 1 the tilting arm 14 (the tilting axis is parallel to the guide 15) is in travelling configuration (i.e. having a certain tilting angle) suitable for avoiding bag interference with the filling nozzles 12. As known, at a filling station 1 1 the tilting arm 14 stops the travelling movement and starts an approaching movement (i.e. a tilting movement) towards the filling station 1 1 for releasing the bag 3 at a filling nozzle 12. In figure 2 the arrows TR and Tl represent respectively the travelling movement along the guide 15 and the approaching/tilting movement toward and away from the filling nozzles 12. Figures 3 and 4 show the packer assembly of figure 2 in two different configurations due to the present of a bag applicator assembly according to the present invention. Figure 3 discloses the valve opening device in a first or lower position with respect to the supporting plane 5. In this first or lower position, the valve opening device 6 is suitable for picking up a bag from the plane 5. Figure 4 discloses the valve opening device in a second of raised position with respect to the receiving plane 5. In particular, in this second or raised position the valve opening device 6 is in position so that the clamping device 16 of the tilting arm 14 can pick up an open bag without any tilting movement starting from the travelling configuration. In particular, the valve opening device 6 reaches this raised position before the arriving of the tilting arm 14 at the opening station 1 . In this example the raised position is reached by a rotation of the valve opening device 6 about an axis (by a hinge connection) parallel to the guide 15 at an inner edge of the plane 15. This rotation is driven by an actuator represented in figures 3 and 4 by the reference 8.

Figures 5-7 disclose an embodiment of a valve opening device 6 according to the invention. In particular this valve opening device 6 comprises a supporting frame 7 pivotally connected with respect to the supporting plane 5. The supporting frame 7 supports a first suction device 9 configured for coupling the bag 3 at the valve 4 and a second suction device 10 configured for coupling the opposite end of the bag 3. Figure 5 schematically represents the valve opening device 6 in the lower position with the second suction devices 9 and 10 acting on a closed bag 3. As represented in figure 6, the first suction device 9 is cyclically movable (i.e. tiltable around an axis orthogonal to the guide 15) with respect to the second suction device 10 for reaching a position wherein the bag 3 is spread and the valve is open 4. The spread of the bag is moreover obtained by the presence of a fixed constrain 20 acting in between the two suction devices 9 10. According to the invention when the valve opening device 6 reaches the configuration of figure 6 the tilting movement of the frame 7 is activated so that the open valve 4 reaches a raised position. As foregoing mentioned (and as represented in figure 7) in this raised position the bag can be picked up by the clamp 16 without requiring any approaching movement to the tilting arm from the travelling condition.

Figures 8 and 9 clarify what is the inline packer and the inline bag applicator within Figure 2 (figure 2 includes both the inline packer and the inline bag applicator). Figure 8 is a schematic view of the inline packer according to the present invention.

Figure 9 is a schematic view of the inline bag applicator according to the present invention. Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention.

Even if the main field of application of the present invention is the cement industry, a valve bag as foregoing described and the valve opening device of the present invention may be used in other technical field, for instance for filling the bags with building materials, fertilizers and chemicals products or also food.

It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.