PACKAGING MACHINE FOR MAKING FILTER BAGS WITH INFUSION

PRODUCTS

Technical field

This invention relates to the technical sector of packaging machines for making filter bags with infusion products.

In particular, the invention relates to a packaging machine of the type suitable for making infusion products (tea, coffee, camomile and the like)

Background art

Generally speaking, the prior art packaging machines comprise a plurality of processing stations at which respective steps are performed which contribute to making the infusion products.

The products are usually made by means of bags made of filter material inside of which at least one dose of a substance designed to be infused is enclosed.

A thread is also associated with the bags which allows the bag to be connected to a gripping tag, making a product ready for grouping and suitably stacked at an outfeed area of the machine which is usually followed by a station for final packaging of infusion products in suitable containers or boxes.

Before the stacking of the filter bags, a packaging of each individual bag may also be made with a sheet of overwrapping material suitably folded and sealed on the bag to form an individual packet with a closed filter bag inside it.

In order to reduce the complexity, the overall size and total cost of the packaging machine the prior art teaches the production of solutions for manual packaging of the bags, wherein at the end of the production process the finished products are manually picked up by the machine and inserted in the respective containers/boxes according to a predetermined number.

For this purpose, it is necessary to prepare an outfeed station which is able to allow a regular conveying of the bags (with or without overwrapping) in succession and with the possibility of manual picking up by an operator.

It is also necessary to be able to define predetermined groups of successive products (in a predetermined number which can at the same time be modified by the operator, to take into account any size changeover of the containers or boxes in which the product will be inserted) so as to allow a fast and optimum picking up by the operator.

In the sector there are prior art packaging machines comprising outfeed stations in which the finished products are grouped together and conveyed along a guide channel having at the top an opening through which the operator can access the products for picking them up and extracting them from the machine.

However, the Applicant has found certain problems which affect the efficiency and the usability of the prior art packaging machines.

In particular, the prior art machines have outfeed stations which are not very effective and require complex transfer mechanisms to correctly perform the passage of the products from the processing stations to the outfeed station.

Aim of the invention

In this context, the technical purpose which forms the basis of the invention is to provide a packaging machine for making filter bags with infusion products which overcomes the above-mentioned drawbacks of the prior art.

In particular, the aim of the invention is to provide a packaging machine for making filter bags with infusion products which is able to optimise the process for moving the filter bags inside the machine, in particular after completing the production of the individual filter bags and during their preparation for packaging in groups of predetermined dimensions and subsequent extraction.

The technical purpose indicated and the aims specified are substantially achieved by a packaging machine for making filter bags with infusion products comprising the technical features described in one or more of the accompanying claims.

The invention relates to a packaging machine for making filter bags with infusion products comprising a plurality of processing stations defining a processing path and configured for making filter bags and an outfeed station situated immediately downstream of the processing path.

The outfeed station in turn comprises a guide channel along which is defined a succession of ordered and continuous filter bags and which has a first curved stretch designed to receive as input the filter bags from the processing path and a second flat stretch designed to allow their extraction from the machine.

The outfeed station also comprises transfer means configured for transferring the filter bags from the processing path to the first stretch of the guide channel.

Advantageously, the machine according to the invention optimises the control of the spaces and facilitates the movement of the filter bags and their splitting into groups of predetermined dimensions.

The dependent claims, incorporated herein for reference, relate to different embodiments of the invention.

Brief description of the drawings

Further features and advantages of the present invention are more apparent in the non-limiting description of a preferred embodiment of it, as illustrated in the accompanying drawings, in which:

- Figure 1 shows in general a diagram of a packaging machine for making filter bags with infusion products according to the invention; - Figure 2 shows in detail a view of an outfeed station of the packaging machine for making filter bags with infusion products of Figure 1 ;

- Figure 3 shows a cross-section of the outfeed station of Figure 2 showing the movements of some elements.

- Figure 4 shows a detail of the outfeed station;

- Figure 5 shows a schematic perspective view of a filter bag made with the packaging machine according to the invention.

Detailed description of preferred embodiments of the invention

In the accompanying drawings, the numeral 1 generically denotes a packaging machine for making filter bags with infusion products, hereinafter denoted simply as the machine 1.

The machine 1 comprises a plurality of processing stations 2 arranged in a precise order designed at defining a processing path along which the filter bag is progressively assembled with infusion products referred to below as infusion product "I".

The filter bag I (see Figure 5) comprises at least one containment chamber having two outer faces 1a, 1b with larger dimensions facing each other and two sides which extend from a bottom 1f and from a top 1c.

The bottom 1f and the top 1c have an extension smaller than both the two large faces 1 a, 1 b and the sides.

This configuration of the filter bag I may vary in its configuration, but the geometry described is the same.

By way of a non-limiting example, the processing stations 2 may comprise a succession of stations designed to make filter bags starting from pieces of filter material and containing one dose (single-lobed bag) or two doses (two-lobed bag) of a substance suitable for infusion (such as, for example, tea, coffee, camomile or the like, and flavouring substances) and applying to these bags a portion of thread having at one end a gripping tag, whilst at the other end, the thread is associated with the filter bag.

Optionally, the processing stations may also comprise a station designed for applying a sheet of overwrapping material to the filter bag after application of the thread and the tag.

The processing stations also comprise a rotary carousel R (preferably rotating about a horizontal axis) having a plurality of radial grippers P configured to retain corresponding filter bags I being formed.

In short, the carousel R defines a conveyor of the filter bag I, along an arc shaped path, in such a way as to reach the other operating stations 2 to allow the complete formation of the filter bag I. For example, the machine 1 may comprise a first processing station 2a wherein the doses of substance for infusion (contained in a hopper 2b) are placed, at predetermined distances, on a continuous strip formed by filter material "M".

The machine 1 may also comprise a second processing station 2c wherein the continuous strip on which the doses are placed is cut and folded to define the shape of the infusion product "I" to which the thread "F" is also applied (for example during the passage of the filter bag I being formed on a gripper P of the carousel R).

As mentioned, the machine 1 also comprises a series of processing stations in which the operations for forming the filter bag "I" moving on the carousel R are completed.

A third station 2d feeds a tag "E" to be applied to the filter bag being formed (tag separated from a continuous web). The tag "E" is then associated with the filter bag "I" and with the thread "F".

A fourth processing station 2e wherein a continuous web of overwrapping material "S" is cut into pieces and wrapped around the filter bag "I" completing its formation.

As mentioned, the movement of the filter bag "I" through the various processing stations 2 and therefore along the entire processing path is performed by means of the above-mentioned rotary carousel R having the radial grippers defining seats designed to receive and retain the filter bags "I" being formed and then supplying them in sequence to the various processing stations 2 during its rotation.

The machine 1 also comprises an extraction station 3 situated immediately downstream of the processing path and which receives from the carousel R the filter bags "I" formed to allow the extraction from the machine 1.

More specifically, the extraction station 3 comprises a stacking unit 4 comprising a guide channel 4b having a rectilinear stretch and configured to allow the ordered and continuous feeding of the filter bags I superposed to form a stack to be extracted from the machine 1. In other words, the infusion products "I" ready to be packaged are progressively transferred and aligned in the guide channel 4a from which they can be picked up (manually) by an operator who will then insert them in a suitable container. As illustrated, the extraction station 3 comprises transfer means 5 configured for transferring the filter bags I coming from the processing path to the stacking unit 4.

In light of this, the transfer means 5 individually pick up the filter bags I from the plurality of grippers P of the carousel R.

Structurally, the stacking unit 4 further comprises a connecting element 4a, positioned downstream of the processing stations 2 and upstream of the guide channel 4b.

The connecting element 4a is configured to receive as input from the transfer means 5 the filter bags I coming from the processing path. Moreover, the connecting element 4a is connected at the outlet with the guide channel 4b in which the filter bags I are introduced before being extracted from the machine.

The connecting element 4a also comprises a chute surface having a curved stretch shaped to allow the feeding of the filter bags I along a feed direction.

Basically, the complete guide channel has a first curved stretch designed to receive as input the infusion products "I" from the processing path and a second flat stretch (both open at the top), in such a way as to allow, if necessary and at any time, an operator to access the infusion products "I", in particular to perform the extraction from the machine 1.

The above-mentioned transfer means 5 are configured and actuated in such a way as to pick up individually in succession the filter bags I from an outfeed station U forming part of the plurality of processing stations 2 and positioning individually, in succession, the filter bags I according to an orientation such as to form a stack of filter bags I superposed on each other along the feed direction and with the respective faces 1a, 1b with larger dimensions positioned transversal to the feed direction and with the respective bottoms 1f positioned side by side resting on the chute surface of the connecting element 4a.

More in detail, the curved stretch of the connecting element 4a has a curvature such as to define, along the feed direction, a feed path for the filter bags "I" having a circular arc shape.

The circular arc extends between an inlet wherein the filter bags "I" are positioned by the transfer means 5 according to a first orientation (almost horizontal) and the outlet wherein the filter bags "I" perform a rotation, after having travelled along the curved stretch, preferably not greater than 90° and greater than 35°, to be positioned according to a second orientation (substantially vertical) different from the first orientation.

In other words, the first stretch 4a has a circular arc shape which allows an inlet of the guide channel 4 positioned in such a way as to favour and promote the insertion of the infusion products "I" whilst at the outfeed they are joined in an optimum manner with the second stretch 4b, which is preferably positioned in a substantially horizontal manner, to facilitate extraction of the products by an operator.

Moreover, the connecting element 4a of the stacking unit 4 comprises lateral facing surfaces (thus facing towards the inside of the channel) which converge in the infeed direction, designed to favour at least a partial retaining of the filter bags "I" by interference with the respective sides of the filter bags I.

In general, therefore, the inner surfaces of the first stretch 4a are located at a distance from each other less than the lateral dimensions or lateral size of the infusion product "I", in such a way as to guarantee that the product cannot adopt incorrect orientations (incline, for example) during its movement.

This convergence may be obtained, for example, by a step made at the inlet of the first stretch 4a, or by a gradual and progressive variation of its thickness.

Alternatively, the reduction in the width of the guide channel 4 inside the first stretch may be achieved by means of a pair of plates "PA" coupled to the inner surfaces of the side walls of the connecting element 4a.

The side walls may also be movable away from/towards each other, in such a way as to allow an operator to adapt the width of the guide channel 4b as a function of the dimensions of the filter bags "I" which the machine 1 must process.

This feature is particularly advantageous if it is necessary to change the size of the machine 1 , for example when changing from products without overwrapping to products which have it or vice versa.

The guide channel 4b comprises, on the other hand, a motor-driven conveyor belt 9 positioned at a relative lower surface (that is, the one on which the filter bags "I” rest), configured for promoting a controlled feed of the products once they come out from the connecting element 4a and up to their removal by the operator.

As mentioned above, the extraction station 3 further comprises the transfer means 5.

The transfer means 5 are made using a gripper 5a movable between a picking up position in which it picks up the filter bags "I" along the processing path (that is, from the outfeed station U) and a release position close to the connecting element 4a for releasing the filter bags "I" in the connecting element 4a.

Operatively, the gripper 5a is moved to the picking up position moving it towards the processing path until engaging and gripping a finished infusion product "I" by a gripper P of the carousel R and ready to be boxed and then moved to the release position, moving it to the connecting element 4a in such a way that the infusion product "I" is in a position such as to enter it once released by the gripper 5a.

To facilitate the entrance of the infusion products "I" inside the first stretch 4a, the machine 1 further comprises pushing means 6 configured to intercept the infusion products "I" at the infeed of the connecting element 4a, pushing them in such a way as to make them slide inside it.

In this way it is possible to prevent the accidental falling of infusion products "I" during their transfer to the connecting element 4a and the correct preparation of a succession of products which is actually continuous and ordered.

In light of this, the pushing means 6 are configured to be actuated in a synchronous fashion with the transfer means 5 in such a way as to pull the filter bag I as soon as it is released by the transfer means 5.

In detail, the pushing means 6 comprise a pair of fingers 6a configured to allow the transfer means 5 to pass between them.

In particular, the pair of fingers 6a is at least partly inserted in the stacking unit 4 and slidable in at least a part of the connecting element 4a.

The pair of fingers 6a may be pivoted above the connecting element 4a in such a way that its rotational movement can follow the arched profile of the connecting element 4a, in particular at its inlet.

The machine 1 also comprises lifting means 7 acting on the connecting element 4a for lifting a single filter bags "I" relative to the stack of filter bags "I" superposed and advancing along the connecting element 4a.

This feature makes it possible to make in the succession of products references which make it possible to identify successions / separations of groups of products each comprising a predetermined number of filter bags "I" which corresponds to the number of products which must be inserted in each box or container.

In other words, the lifting means 7 periodically lift the succession of products by lifting the filter bags "I" at regular intervals and therefore located at a predetermined reciprocal distance.

In this way, a visual indicator (flag) is provided which allows the operator to identify immediately and easily where the group of products starts and finishes, containing the exact number of filter bags "I" which must be picked up and boxed.

Structurally, the lifting means 7 comprise a lever 7a positioned on the chute surface of the connecting element 4a, in particular at a lower surface of the connecting element 4a.

The lever 7a is movable between a lowered home position wherein it acts in conjunction to define, with the chute surface, a shared lower surface of the connecting element 4a on which the filter bags "I" slide, and a raised operating position, wherein the lever 7a is positioned at a certain height relative to the chute surface, in such a way as to intercept and lift a filter bag "I" sliding inside the connecting element 4a.

Preferably, the lever 7a is pivoted at a relative end at the lower surface of the connecting element 4a and the passage from the home position to the operating position and vice versa is performed by a rotational motion. Alternatively, the lever 7a could be moved in a linear fashion perpendicularly to the lower surface, causing a progressive insertion in the connecting element 4a, when moved from the home position to the operating position.

The extraction station 3 also comprises an end of stroke element 8 positioned in the guide channel 4b and slidable inside it and configured for making contact against the filter bag I in a more advance position of said succession of stacked products.

In other words, the end of stroke element 8 is configured for making contact against a first filter bag "I" of the succession of products in such a way as to keep it in the correct position, thus guaranteeing that the succession of products remains ordered and compact.

In this way it is also possible to guarantee that the products which have been raised by the lifting means 7 do not fall, being aligned with the other products, under the effect of the force of gravity.

In fact, the products which have been raised are held in position under the action of the pressure applied by the adjacent products and generated also thanks to the action of the end of stroke element 8.

In order to optimise the operation of the end of stroke device 8, the outfeed station 3 comprises elastic means which are active on it, in such a way as to keep it securely in contact against the first filter bag "I".

For this reason, even during and after the removal of a group of infusion articles by the operator, the elastic means ensure that the end of stroke element 8 is returned automatically and quickly in contact with the new first filter bag "I", thereby avoiding in this way that the succession of products unpacks, resulting in a re-alignment of the predetermined products which have been raised and the consequent loss of the reference which allows the operator to identify the start and end point of the individual groups.

The invention also provides a method for making filter bags "I" with infusion products.

The method comprises the following steps:

- preparing a processing path along which the filter bags I are formed; - picking up individually the filter bags I at the end of the processing path;

- releasing in succession filter bags I picked up on a connecting element 4a of a stacking unit 4 according to an inlet orientation such as to form a stack of filter bags I superposed on each other along a feed direction, with the respective large faces 1a, 1b positioned transversal to the feed direction and with the respective bottoms 1f positioned alongside each other resting on an arched chute surface of the connecting element 4a;

- introducing, by pushing, the filter bags I stacked and in succession from each other by the connecting element 4a in an adjacent guide channel 4b of the stacking unit 4 for forming a group of stacked filter bags I to be extracted, wherein the introduction in the guide channel 4b occurs according to an outlet orientation different from the infeed orientation and after the filter bags I have rotated along the curved chute surface. Preferably, between the releasing step and the step of introducing into the guide channel, the filter bags I perform a rotation preferably not greater than 90° and greater than 35°, to be positioned according to the outlet orientation.

Preferably, between the releasing step and the introducing step there is a step of lifting a single filter bag I relative to the stack of superposed filter bags I.

It should be noted that the bottom 1f of the filter bag I, whilst it moves forward along the chute surface, travels along an arcuate stretch having a length greater than the stretch travelled by the top 1 c of the filter bag I. Advantageously, the invention achieves the preset aims overcoming the drawbacks of the prior art by providing the user with a packaging machine which is structurally simple and compact which allows the infusion products "I" made by their processing path to be extracted in a simple and efficient manner. In particular, the geometry of the extraction station makes it possible to have each filter bag inserted at the infeed always constantly controlled during its feeding through simple mechanical systems and which is able to modify their angular position through the constant feeding towards the outfeed.

Moreover, the arc-shaped stretch allows auxiliary operations to be performed, such as the lifting of the filter bag "flag” during the first inlet, and may be adjusted as a function of the type and movement of the transfer means.