ES2784906T3 - Filter bag forming machine for infusion products with folding stations - Google Patents

Abstract

A machine for forming filter bags containing infusion products of the type comprising a piece (1) of filter material with an elongated shape having at least two chambers (2, 3) containing corresponding doses (D1, D2) of product of infusion; the machine (100) comprising: - a bending station (4) designed to bend the piece (1) of filter material and positioned along a line (L) for feeding and shaping; - a receiving carousel (8) designed to receive from the bending station (4) and move the piece (1) of filter material to at least one operating station designed to make a filter bag from the piece (1) of filter material; the bending station (4) comprising: - two receiving surfaces (5, 6) designed to receive the piece (1) of filtering material and having surfaces that mutually converge to define a channel (7) leading towards the receiving carousel (8 ); - a pair of gripping elements (9, 10) operatively positioned on opposite sides of the channel (7); - movement means (11) designed to move with a synchronized reciprocal movement the gripping elements (9, 10) towards and away from the receiving carousel (8); the pair of gripping elements (9, 10) acting on the two sides in an intermediate zone (1a) of the piece (1) of filtering material to bend, and transfer to the underlying receiving carousel (8), the piece (1) of filtering material, characterized in that the bending station (4) comprises: - two smooth auxiliary walls (12, 13), one for each receiving surface (5, 6), with the possibility of movement between an operative position to receive, where the smooth auxiliary walls (12, 13) receive the piece (1) of filter material that advances along a feed line and are mutually coplanar, and an operative position for controlled release, where the smooth auxiliary walls (12, 13) are inclined towards the channel (7) defined by means of the receiving surfaces (5, 6) and are designed to release in a controlled manner the piece (1) of filter material to the underlying receiving carousel (8); - movement devices (14), synchronized with the movement means (11), designed to move the smooth auxiliary walls (12, 13) from the operative position for receiving to the operative position for controlled release and vice versa.

Description

DESCRIPTION

Filter bag forming machine for infusion products with folding stations

Technical field

This invention relates to a machine for making filter bags for infusion products.

Previous technique

The expression "infusion products" means products such as tea, coffee, chamomile (powder, granules, or leaves). More specifically, a machine in accordance with the invention is used to form filter bags of the so-called two-lobe type, that is, filter bags comprising a single piece of filter paper defining two separate and closed chambers. Each chamber contains one dose of infusion product. The two chambers are bent towards each other forming a single upper end (in the shape of a flipped "V") and a lower end in the shape of a "W". The filter bag can also be equipped with a thread for association with a grip tag.

Patent document EP765274 (filed by this applicant) describes a machine for forming a filter bag of the type described.

That patent document describes a structured machine along a forming and feeding line in which they are positioned:

- a station for feeding a filter paper web along a feeding surface;

- a station for feeding doses of product into the filter paper weft at predetermined distances;

- a station designed to close the weft by itself, wrap the doses of product and, subsequently, follow the weft longitudinally;

- a station for folding individual pieces of filter paper with double chamber;

- a carousel equipped with radially protruding clamps, positioned below the folding station and configured to receive individual pieces of folded filter paper; the carousel, gradually moved around a horizontal axis, moves each piece of filter paper near the stations arranged one after the other to associate a thread to the piece of filter paper, duly wound around the piece of filter paper, and an associated label turn with the thread.

In some machine solutions, depending on the type of filter bag, there may be:

- yet another station for the transverse closing of the ends of the piece before or at the same time as the separation of the remaining film; or

- a station for bending the open ends of the two chambers of the piece along the path of the carousel. If necessary, there may also be a station for applying a wrapping material to the filter bag thus obtained along the path of the carousel.

Of particular relevance to this specification is the station for folding the pieces of filter paper.

This station includes:

- a pair of fixed bearing surfaces configured with a convergent extension of one another, to define a channel for descending towards the underlying carousel with radial clamps;

- a pair of gripping elements designed to make contact with the two sides of a piece of filter paper, which can be moved between the fixed surfaces and to and from the carousel to take from the receiving station, fold in combination with the surfaces fixed, and transfer the piece of filter paper to a clamp on the carousel.

More specifically, the purpose of the pair of gripping elements is to guide the tubular piece of filter paper from a rectilinear configuration to a two-part folded configuration placed side by side.

Once folded, the piece of filter paper is delivered to a gripper on the carousel.

The two grippers have operating ends configured to form a "W" -shaped fold in a central portion of the filter paper piece and guide the filter paper piece into the carousel in a controlled manner. Furthermore, the bending station comprises two press elements, movable in synchronization with the gripping elements, designed to hold the free ends (opposite each other) of the piece of filter paper that is formed against the fixed bearing surfaces in such a way as to prevents the product from escaping.

It should be mentioned that the press elements come into contact with the piece of filter paper after the piece reaches the fixed bearing surfaces, during the step of forming the "W" -shaped fold and in the first step of a descent. controlled piece of filter paper into the carousel.

For filter bags of standard size and weight, the station structured in this way has high-level precision and operational reliability characteristics.

Both for market strategies and to increase the infusion quality of each individual filter bag, it is necessary in each chamber to increase the amount of product within the filter bag with a relative increase in weight, which, in fact, has generated inconveniences in the machine, in particular, at the bending station.

In more detail, precisely due to the increased weight, it is difficult to position correctly on the fixed support surfaces, and to bend, the piece of filter paper, which tends to fall due to gravity in an uncontrolled way towards the descent channel, before gripper units come into operation.

Disclosure of the invention

The aim of this invention is to provide a machine for forming filter bags containing infusion products that can overcome the above-mentioned drawbacks.

More specifically, the object of this invention is to provide a machine for forming filter bags for infusion products that is capable of operating at a high production speed even with heavy and large filter bags.

These objectives are fully achieved by means of a machine for forming filter bags containing infusion products according to claim 1.

More specifically, the machine according to the invention comprises a bending station, designed to bend a piece of filter material and positioned along a forming and feeding line, and a receiving carousel designed to receive from the bending station and move the piece of filter material to at least one operating station designed to make a filter bag from the piece of filter material.

An example of filter material is filter paper, which is referred to later in the description for reasons of simplicity, but it is understood that the invention has application with any suitable filter material to be folded into filter bags for infusion products, such as, for example, with polymeric materials.

The folding station comprises two receiving surfaces designed to receive the piece of filter paper and having respective mutually convergent surfaces to define a channel leading towards the receiving carousel.

The bending station also comprises a pair of gripper elements operatively positioned on opposite sides of the channel and movement means designed to move the pair of gripper elements with synchronized reciprocal movement to and from the receiving carousel. Furthermore, the gripping elements are configured to act on both sides in an intermediate zone of the piece of filter paper positioned along the receiving surfaces to fold in combination with the receiving surfaces, and transfer to the receiving carousel, the piece of paper filter.

According to the invention, the bending station also comprises two smooth auxiliary walls, one for each receiving surface.

The smooth auxiliary walls can be moved between an operative position to receive, where the smooth auxiliary walls receive the piece of filter material that advances along a feed line and are mutually coplanar, and an operative position for controlled release, wherein the smooth auxiliary walls are inclined towards the channel defined by the receiving surfaces and are designed to release in a controlled manner the piece of filter paper to the receiving carousel.

Advantageously, the receiving carousel is positioned below the folding station.

The bending station also comprises movement devices, synchronized with the movement means, designed to move the smooth auxiliary walls from the operative position for receiving to the operative position for controlled release and vice versa. In other words, each smooth auxiliary wall is connected to devices of movement synchronized with the means of movement of the gripping elements, to move each smooth auxiliary wall from a first operative position to receive the piece of filter paper, where the two smooth walls are coplanar with respect to each other and parallel to the feed line, to a second operative position for the controlled release of the piece of filter paper, where the two smooth walls are inclined towards the channel defined by the receiving surfaces.

Furthermore, advantageously, the bending station comprises two press elements, each one of them located above a respective receiving surface and with the possibility of movement in a synchronized way with the gripping elements between an elevated inoperative position, where the clamping elements press are spaced apart from the receiving surfaces, and an operative position to hold, wherein the press elements are in contact with, and push against the relative receiving surface, corresponding free ends of the piece of filter paper, at least in the first position operation of smooth auxiliary walls.

Thanks to a machine structured in this way, the pieces of filter paper are positioned horizontally on the auxiliary smooth walls and, only after the gripping elements and / or the press elements have received and locked them, are they bent and move toward the receiving carousel. Therefore, there are no uncontrolled falls or errors when positioning the piece of filter paper, because until the piece of filter paper is blocked by the gripping elements and / or by the press elements, it remains resting on a surface. horizontal formed by smooth auxiliary walls.

Brief description of the drawings

These and other characteristics of the invention will become more apparent from the following detailed description of a preferred non-limiting embodiment thereof, with reference to the accompanying drawings, in which:

figure 1 illustrates a perspective view, with some parts cut away to better illustrate others, of a bending station of a machine according to the invention in a configuration for receiving a piece of filter paper (not illustrated);

figure 2 illustrates a perspective view, with some parts cut away to better illustrate others, of the folding station of figure 1 in a configuration for folding the piece of filter paper;

Figures 3 to 6 illustrate front views, with some parts cut away to better illustrate others, of the folding station of Figures 1 and 2, in a corresponding series of operating configurations in which it receives, folds and transports the piece of paper filter onto a receiving carousel positioned below the bender station.

Detailed description of preferred embodiments of the invention

With reference to the accompanying drawings, in particular Figures 3 to 6, a machine according to the invention, labeled 100 in its entirety, is used to form filter bags containing infusion products. The term "infusion products" means products such as tea, coffee and chamomile dosed in powder, granules, or leaves.

The filter bag formed by means of a machine according to the invention comprises a piece 1 of filter paper with an elongated (tubular) shape having at least two chambers 2, 3 containing corresponding doses D1 and D2 of infusion product and separated the one of the other.

The two chambers 2, 3 are bent towards each other forming a single upper end (in the shape of an upturned "V") and a lower end in the shape of a "W".

The machine 100 comprises, along a forming and feeding line L, a plurality of stations (of a known type and, therefore, not illustrated) designed to cut out and form a piece 1 of filter paper with the two chambers 2, 3 (containing doses D1 and D2) separated by an intermediate zone 1a.

The machine 100 also comprises, again along the forming and feeding line L, a bending station 4, designed to bend opposite ends of the piece 1 of filter paper and comprising at least two receiving surfaces 5, 6 designed to receive piece 1 of filter paper. The receiving surfaces 5, 6 have surfaces that mutually converge to define a channel 7 leading to an underlying receiving carousel 8 designed to receive the piece 1 of filter paper once it has been folded in the folding station 4 (the receiving carousel 8 it is only partially illustrated with a broken line in figure 6).

The receiving surfaces 5, 6 have a curved shape that determines a mutual movement towards each of the chambers 2, 3 while the piece 1 of filter paper approaches the receiving carousel 8.

The bending station 4 also comprises a pair of gripper elements 9, 10 operatively positioned in opposite sides of the channel 7 and movement means 11 designed to move with a synchronized reciprocal movement the pair of gripping elements 9, 10 towards and away from the receiving carousel 8.

The gripping elements 9 and 10 act on both sides, in the intermediate zone 1a, on the piece 1 of filter paper to fold (from a smooth configuration to a configuration with two chambers side by side, figures 3-5 ), and transfer (figure 6) to the underlying receiving carousel 8, the piece 1 of filter paper.

In accordance with the invention, the bending station 4 comprises two smooth auxiliary walls 12, 13, one for each receiving surface 5, 6.

The smooth auxiliary walls 12, 13 can be moved between an operative position to receive, where the smooth auxiliary walls 12, 13 receive the piece 1 of filter paper that advances along a feed line and are mutually coplanar (Figures 3 and 4), and an operative position for controlled release, where the smooth auxiliary walls 12, 13 are inclined towards the channel 7 defined by means of the receiving surfaces 5, 6 and are designed to release the piece 1 in a controlled manner of filter paper to the underlying receiver carousel 8 (Figures 5 and 6).

In detail, the smooth auxiliary walls 12, 13 in the operative position to receive are positioned horizontally one after the other along the feeding and shaping line L and define a bearing surface for the piece 1 of filter paper. The smooth auxiliary walls 12, 13 in the operative position to receive can be mutually positioned at such a distance to leave an opening, which is small enough not to allow the piece 1 of filter paper to fall due to gravity towards channel 7.

The bending station 4 also comprises movement devices 14, synchronized with the movement means 11, designed to move the smooth auxiliary walls 12, 13 from the operative position for receiving to the operative position for controlled release and vice versa.

Preferably, each smooth auxiliary wall 12, 13 comprises a movable portion of the corresponding receiving surface 5, 6 (see Figures 1, 2).

It should be mentioned that each smooth auxiliary wall 12, 13 comprises a support grid 15, connected, at one end 15a, to an articulation shaft 16 connected to the movement devices 14.

Preferably, each receiving surface 5, 6 is formed by a box-shaped frame 17 having a curved active surface 18 and a smooth receiving surface 19 parallel to the feed line L.

In light of this, each receiving surface 5, 6 comprises a plurality of grooves 20 that are longitudinal and mutually parallel, designed to mesh by means of a corresponding support grid 15 positioned in the second position for controlled release.

In other words, the configuration of the smooth auxiliary walls 12, 13 and the receiving surfaces 5 and 6 is such that, in the operative position for controlled release, the smooth auxiliary walls 12, 13 are fundamentally concealed within the frame-shaped frame. box 17.

It should therefore be mentioned that in the release operative position only the receiving surfaces 5, 6 define respective bearing surfaces of the piece 1 of filter paper.

Advantageously, the articulation shaft 16 is housed in the box-shaped frame 17 of a corresponding receiving surface 5, 6 and below a corresponding smooth receiving surface 19.

In light of this, the devices 14 for moving the smooth auxiliary walls 12, 13 comprise a crank 21 for each articulation shaft 16.

The cranks 21 are mutually connected by means of a control rod 22 which is capable of mutually synchronizing the movements of the smooth auxiliary walls 12, 13. Furthermore, the rod 22 is connected to actuating devices 23, which are connected to means of centralized cam (not illustrated) that are designed to synchronize the steps for the movement of the smooth auxiliary walls 12, 13 with the movement members 11, the gripping elements 9, 10 and with the movement (in a gradual manner) of the carousel receiver 8.

The actuator devices 23 may, for example, comprise levers connected to the cam means which are centralized and which can directly control the movement of the control rod 22.

Furthermore, the bending station 4 comprises two press elements 24, 25, each of them located above a respective receiving surface 5, 6 and with the possibility of movement in a synchronized manner with the gripping elements 9, 10 between a position raised inoperative (Figures 1, 3, 4 and 6), wherein the press elements 24, 25 are spaced apart from the receiving surfaces 5, 6, and an operative position to retain (figure 5), wherein the press elements 24, 25 are in contact with corresponding free ends of the piece 1 of filter paper, at least in the first operative position of the smooth auxiliary walls 12, 13.

Once the press elements 24, 25 have contacted and locked the free ends of the filter paper piece 1 against the receiving surfaces 5, 6, the smooth auxiliary walls 12, 13 are moved from the operative position to receive, where they support the piece 1 of filter paper, up to the operative position for controlled release, where they do not make contact with the piece 1 of filter paper that is supported only by the receiving surfaces 5, 6.

In light of this, each press element 24, 25 has a contact head 24a, 25a configured in the shape of a spatula and equipped, on one surface, with a plurality of teeth 26 that mesh, in the operating position of retention, with at least one groove 20 made in a receiving surface 19 of a corresponding receiving surface 5, 6.

Thanks to the press elements 24, 25, the piece 1 of filter paper fed into the smooth auxiliary walls 12, 13 is secured at the ends during a first gripping step on both sides by means of the gripping elements 9, 10 , and then is accompanied during the descent step. It should be mentioned that during the lowering step there is no risk of product escaping from the piece 1 of filter paper precisely because the contact heads 24a, 25a of the press elements 24, 25 keep the ends of the piece 1 of filter paper pressed against the receiving surfaces 5, 6.

It should be mentioned that the press elements 24, 25 comprise a pair of shafts that support the heads 24a and 25a and are articulated on a shared axis, positioned above the heads 24a and 25a. The pair of shafts forms a type of orientation which, in the open position, allows the heads 24a and 25a to come into contact with corresponding ends of the piece 1 of filter paper which are therefore blocked between the heads 24a and 25a and the respective receiving surfaces 5, 6.

The pair of shafts, when closing and descending, allow the heads 24a and 25a to follow the ends of the piece 1 of filter paper that slides downwards along the receiving surfaces 5, 6 pushed by the gripping elements 9, 10.

Finally, the pair of shafts can be moved upwards (away from the piece 1 of filter paper) and be positioned in the open position, to allow the heads 24a and 25a to come into contact with a succession of pieces 1 of filter paper. The gripping elements 9, 10 each have a respective operating head 9a, 10a, mutually shaped to define a fold in the shape of a "W" in the intermediate zone 1a of the piece 1 of filter paper. In summary, the gripping elements 9, 10 are embedded in the intermediate zone 1a of the piece 1 of filter paper, forming the fold in the shape of a "W".

The heads 9a, 10a of the gripping elements 9, 10 are connected with and are moved by corresponding support arms.

The receiving carousel 8 comprises a plurality of radial gripping arms 8a defining individual housings for the pieces 1 of filter paper.

In summary, the bending occurs as follows:

- receiving the piece 1 of filter paper, which advances along the feed line, on the smooth walls 12, 13 mutually positioned coplanar in an operative position to receive (figure 3);

- bilateral movement of the gripping elements 9, 10 to the intermediate zone 1a of the piece 1 of filter paper (figure 4);

- blocking the ends of the piece 1 of filter paper by means of the press elements 24, 25, gripping on both sides of the piece 1 of filter paper by the intermediate zone 1a by means of the gripping elements 9, 10 and simultaneously forming the fold in the shape of a "W" (figure 5);

- pushing the piece 1 of filter paper by means of the gripping elements 9, 10 towards the underlying receiving carousel 8 through the channel 7, while the press elements 24, 25 continue downwards, and keep pressed against the auxiliary walls smooth 12, 13, the ends of the piece 1 of filter paper and the smooth auxiliary walls 12, 13 inclined towards the channel 7 (figure 6).

In detail, the smooth auxiliary walls 12, 13, in a position of maximum inclination, are aligned with the active surfaces 18 in a final phase of folding the piece 1 of filter paper, before it is received by a radial gripping arm 8a of the receiver carousel 8.

From this description it is clear that, thanks to the machine structured in this way, the piece of filter paper it is always correctly positioned and kept under control during the bending step.

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Claims (8)

1. A machine for forming filter bags containing infusion products of the type comprising a piece (1) of filter material with an elongated shape having at least two chambers (2, 3) containing corresponding doses (D1, D2) of infusion product; comprising the machine (100): - a bending station (4) designed to bend the piece (1) of filter material and positioned along a line (L) for feeding and shaping; - a receiving carousel (8) designed to receive from the bending station (4) and move the piece (1) of filter material to at least one operating station designed to make a filter bag from the piece (1) of filter material; comprising the bending station (4): - two receiving surfaces (5, 6) designed to receive the piece (1) of filter material and having surfaces that mutually converge to define a channel (7) leading towards the receiving carousel (8); - a pair of gripping elements (9, 10) operatively positioned on opposite sides of the channel (7); - movement means (11) designed to move with a synchronized reciprocal movement the gripping elements (9, 10) towards and away from the receiving carousel (8); the pair of gripping elements (9, 10) acting on the two sides in an intermediate zone (1a) of the piece (1) of filter material to bend, and transfer to the underlying receiving carousel (8), the piece (1) of filter material, characterized in that the bending station (4) comprises: - two smooth auxiliary walls (12, 13), one for each receiving surface (5, 6), with the possibility of movement between an operative position to receive, where the smooth auxiliary walls (12, 13) receive the piece (1) of filter material that advances along a feed line and are mutually coplanar, and an operative position for controlled release, where the smooth auxiliary walls (12, 13) are inclined towards the channel (7) defined by means of the receiving surfaces (5, 6) and are designed to release in a controlled manner the piece (1) of filter material to the underlying receiving carousel (8); - movement devices (14), synchronized with the movement means (11), designed to move the smooth auxiliary walls (12, 13) from the operative position for receiving to the operative position for controlled release and vice versa. The machine according to the preceding claim, wherein each receiving surface (5, 6) comprises a box-shaped frame (17) having a curved active surface (18) and a smooth receiving surface (19) parallel to the line feed (L). The machine according to the preceding claim, wherein each smooth auxiliary wall (12, 13) comprises a support grid (15), connected, at one end (15a), to an articulation shaft (16) connected to the devices movement (14). The machine according to the preceding claim, wherein each receiving surface (5, 6) comprises a plurality of grooves (20) that are longitudinal and mutually parallel, designed to mesh by means of a corresponding support grid (15) positioned in the second operating position for controlled release. The machine according to claim 3 or 4, wherein the articulation shaft (16) is housed in the box-shaped frame (17) of a corresponding receiving surface (5, 6) and below a smooth receiving surface (19) corresponding. The machine according to any of the preceding claims, wherein the movement devices (14) of the smooth walls (12, 13) comprise a crank (21) for each articulation shaft (16); the cranks (21) being mutually connected by means of a control rod (22) that can mutually synchronize the movements of the smooth auxiliary walls (12, 13); the rod (22) being connected to control actuator devices (23). 7. The machine according to any of the preceding claims, wherein the bending station (4) comprises two press elements (24, 25), each of them located above a respective receiving surface (5, 6) and with the possibility of movement in a synchronized manner with the gripping elements (9, 10) between a raised inoperative position, where the press elements (24, 25) are spaced apart from the receiving surfaces (5, 6), and an operative position to retain, where the press elements (24, 25) are in contact with, and push against, the relative receiving surface (5, 6), corresponding free ends of the piece (1) of filter material, at least in the first operating position of the smooth auxiliary walls (12, 13). The machine according to claim 7, wherein each press element (24, 25) has a contact head (24a, 25a) configured in the shape of a spatula and equipped, on one surface, with a plurality of teeth ( 26) which engage, in the retention operative position, with at least one slot (20) made in a receiving surface (19) of a corresponding receiving surface (5, 6).