Description

Automatic machine for making filter bags for infusion products

Technical Field

This invention relates to an automatic machine for making filter bags for infusion products such as tea, coffee, camomile and the like.

In particular, the invention is advantageously used for making groups of products defined by a predetermined number of filter bags each containing a charge of infusion product, preferably tea or the like, to which this specification expressly refers but without thereby restricting the scope of the invention.

Background Art Usually, automatic machines for packaging/making filter bags comprise a plurality of operating stations located one after the other along respective production lines where the filter bags are made, each filter bag containing a charge of infusion product enclosed in a chamber of the filter bag.

Depending on the type of product and machine, the filter bags may have one or two chambers and may be associated, using any of several known methods (such as knotting, heat-sealing or application of heat-sealable stamp) with a tie string that connects the filter bag to a tag joined to the free end of the string in any of several different ways (for example, knotting, heat-sealing or application of a stamp). The tie string and tag are placed on the filter bag (for example, wound around the filter bag or placed between the two chambers) to form a product that is ready to be grouped and suitably stacked in the area at the end of the production line where there is a filter bag stacldng station, usually followed by a final packaging station which places the stacks or groups of stacks of filter bags in suitable containers or cartons. In many cases, before the filter bags are stacked, they are overwrapped with individual wrappers, each suitably folded into the shape of a U around a filter bag and sealed to form the typical envelope-like packet containing the filter bag.

At present, depending on circumstances and on the place where the tea-bag making machine is to be used, especially if low-cost labour is available, manufacturers of automatic tea-bag machinery are opting more and more for

"simplified" solutions, where the filter bags are packaged manually, thus avoiding the need to provide machines with automated end-of-line packaging stations and thus reducing costs and saving factory floor space.

For this purpose, the tea bag making machine must be provided with an end-of-line station designed to feed out the filter bags (with or without overwrap) at a regular rate, in succession, at some distance from the machine, and in such a way that production operators can easily pick them up manually.

In addition to this, the outgoing filter bags must be divided up into well- defined successive groups along the feed line of the end-of-line station (each group containing a predetermined number of filter bags which may, however, be changed when necessary), so that the operator can pick them up easily and without hesitation, knowing exactly that the groups contain the right number of filter bags to be placed in the cartons.

The Applicant's aim was therefore to design an automatic machine for making filter bags for infusions products, whose structure comprises an end section with a product outfeed station adapted to form groups containing predetermined numbers of filter bags which can be picked up manually, without altering the basic structure and productivity of the machine and maintaining the machine's high level of performance, dependability and adaptability.

Disclosure of the Invention

This invention accordingly provides a machine for making filter bags for infusion products, the machine being of the type comprising, one after the other along a production line, a plurality of operating stations designed to form the filter bags and at least one operating outfeed station for handling the filter bags made; the machine being characterised in that the operating outfeed and handling station comprises conveying means designed to successively pick up and withhold the filter bags along a certain section of the line; supporting guide means along which an ordered and continuous succession of filter bags is formed and fed along another section of the line; and means for picking up and transferring the filter bags from the conveying means to the supporting guide means.

Brief Description of the Drawings

The technical characteristics of the invention, with reference to the above aims, are clearly described in the claims below and its advantages are apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a preferred embodiment of the invention provided

merely by way of example without restricting the scope of the inventive concept, and in which:

Figure 1 is a schematic side view, with some parts cut away in order to better illustrate others, of an end or end-of-line section of an automatic packaging machine for making filter bags for infusion products;

Figure 2 is a front perspective view of a working detail of the outfeed part of the machine of Figure 1;

Figures 3, 4 and 5 are perspective views from above, with some parts cut away in order to better illustrate others, showing three different working positions of respective operating elements located at the outfeed part of the machine of Figure 1;

Figure 6 illustrates a detail from Figure 1 in a plan view from above;

Figures 7 and 8 are schematic side views showing two further operating elements of the machine according to the invention in two different working configurations.

Detailed Description of the Preferred Embodiments of the Invention

With reference to the accompanying drawings, in particular Figures 1 and 2, the machine according to the invention, labelled 100 in its entirety, is used for making filter bags 1 for infusion products, such as tea, coffee, camomile and the like.

Preferably, but not necessarily, the filter bag 1 is of the type comprising: one chamber 2 containing one charge 3 of infusion product; a tie string 4 joined at one end to the chamber 2; and a tag 5 joined to the other end of the tie string 4. Obviously, the filter bags 1 made and handled by the machine may be of the type without tag and tie string, without thereby restricting the scope of the invention.

The machine 100 is of the type comprising, one after the other along a production line P, a series of known operating stations (not described and illustrated in detail since they are not relevant to the invention) designed to form the filter bags 1, join each filter bag 1 to the tie string 4, join the tag 5 to the tie string 4 and then arrange the tie string 4 and the tag 5 on the filter bag 1.

As better illustrated in Figure 1, the machine 100 also comprises an intermediate station 6 for picking up and transferring the finished filter bag 1 to an end-of-line filter bag 1 handling station or unit 7. The intermediate station 6 is defined by a known drum 6t for picking up and moving the filter bags 1.

As illustrated in Figures 1 to 6, the above mentioned end-of-line unit 7,

which this invention is specifically concerned with, comprises: a first conveying element 8 for picking up each single filter bag 1 as it arrives from the intermediate station 6, feeding the filter bag 1 along a section Tl of the line P and positioning it on a supporting channel 9 that transports an ordered and continuous succession of 5 filter bags 1 along a straight section T2 of the line P to a handling area 10 (Figure 6) where they can be picked up manually and subsequently packaged, for example by placing them manually in suitable cartons; means 11 for picking up each filter bag 1 from the first conveying element 8 and moving the filter bag 1 within the channel 9 in a feed direction A along the section T2 in such a way as to produce a 0 continuous succession of filter bags 1 in the channel 9.

Figure 1 also shows that the unit 7 further comprises actuating means 12 for defining a reference or separator between two consecutive sets of a predetermined number of filter bags 1 in order to form separate groups 13 of filter bags 1 to be picked up manually from the channel 9. 5 In particular, the means 12 are located in the vicinity of the end of the channel 9 where the filter bags 1 from the first element 8 are fed in .

As illustrated in Figures 1 to 5, the first pick-up element 8 consists of a first rotating conveyor drum 8 (arrow F8, Figure 1) located in the vicinity of the second drum 6t for moving the filter bags 1 (the rotation direction of the second drum 6t o being indicated by the arrow F6) in such a way as to receive single filter bags 1 from the second drum 6t.

The first drum 8 has a plurality of cells 20, uniformly distributed on its circumferential surface, for receiving the individual filter bags 1, released by the second drum 6t and transporting the filter bags 1 to a position close to the channel 5 9.

Each of the cells 20 has two longitudinal grooves 21 (Figures 3 and 4) which, when the cell 20 passes near the infeed end of the channel 9, accommodate two vertical teeth 17 constituting, as described in more detail below, the aforementioned means 11 for picking up each filter bag 1. 0 In addition to that, each cell 20 on the drum 8 has a finger unit 22 on each side of it for retaining the filter bag 1 in the cell 20.

Each finger unit 22 is pivoted, at 22a (Figures 1, 2 and 3), to a rigid arm 23 protruding laterally from the first drum 8: thus, each finger unit 22 can be turned from a first, closed retaining position, where the finger unit 22 at least partially 5 faces the filter bag 1 located in the cell 20 and engages, with its fingers 22d, respective lateral openings 20a in the cell 20 (Figure 2), and an open position for feeding / releasing the filter bag 1, where each finger unit 22 is away from the cell

20 (Figures 2 to 4).

Again with reference to Figures 1 to 5, the pick-up means 11 comprise a filter bag 1 ejector element 11 located between the first pick-up drum 8 and the channel 9 infeed area. The ejector element 11 is driven in the feed direction A (arrow FIl, Figure

1), by respective means 16 (partly visible in Figure 1 as two levers 11a, lib of a four-bar linkage connected to a cam system that synchronises it with the first drum 8) between a first pick-up position, where the ejector element 11 is positioned between the first pick-up element 8 and a respective filter bag 1 (see Figures 1 and 5), and a release position, where the ejector element 11 is inside the channel 9, with the filter bag 1 positioned between the walls 9a of the channel 9 (see Figure 4), and vice versa.

As stated above, the ejector element 11 comprises a pair of vertical teeth 17 for pushing the filter bag 1, associated with a base 18, in such a way as to form, together with the teeth 17, a U shaped element controlled by the cam system 16 which drives it and coordinates its motion, from the pick-up position to the release position and vice versa.

As illustrated in Figures 4, 5 and 6, the channel 9 may be composed of a first, infeed section 30 having side walls 9a converging towards the inside of the channel 9 itself and designed to retain the filter bag 1 temporarily in the infeed area, and a successive second section 24 whose passage width L is at least equal to the width Ll of the filter bags 1 in transit.

Further, the base 24b of the second section 24 at least partly cooperates with a portion 25r of a power-driven conveyor belt 25 designed to permit the movement of the filter bags 1 in the feed direction A towards the manual pick-up and handling area 10.

The second section 24 may also be equipped with respective side walls 24a that can be moved (using customary mechanisms) in order to adjust the passage width L according to the width Ll of the filter bags 1 (arrows F24a). As clearly illustrated in Figure 1, the actuating means 12 consist of means

12 for lifting a predetermined incoming filter bag Ia with respect to the other filter bags 1 in order to define the above mentioned reference.

The means 12 are located under the channel 9 and, when required, are operated upon by respective drive means 14 (comprising a customary cam system, not illustrated) in such a way as to act on the bottom of the single filter bag Ia so that the latter moves upwards.

Again with reference to Figure 1, the means 12 may comprise a lever 15,

located under the plane defined by the channel 9 and pivoted, at 15a at one end of it, to a frame 101 in such a way as to move, when acted upon by the drive means 14, between an idle position (dashed line in Figure 1) where the lever 15 is away from the channel 9, and a working position where the lever 15 rises and with its 5 free end engages an opening in the channel 9 in such a way as to contact and raise the predetermined filter bag Ia (continuous line in Figure 1).

At its free end, the lever 15 has a wedge-shaped head 15t forming an inclined surface 15p, and whose upper vertex is away from the infeed area of the channel 9 so that when the lever 15 is in the raised position, the filter bag Ia is 0 lifted as it goes in.

As illustrated in Figures 7 and 8 and partly also in Figures 4 and 5, the unit

7 comprises safety means 26 located close to the infeed end of the channel 9, acting on a main control unit 27 of the machine 100 (illustrated as a generic block) and designed to produce a signal that stops the machine 100 in the event of a fault 5 in the mechanism that moves / feeds the filter bags 1 into the channel 9.

More specifically, the safety means 26 comprise a pair of parallel control rods 28 associated with a block 29 linked to the channel 9.

The rods 28 are coupled, by interference, with the respective side walls 9a of the infeed area of the channel 9 so that, when the machine 100 is working o normally at steady state, they are parallel with the channel 9 on both sides of the pick-up means 11 and underneath the area where the filter bags 1 pass (see Figures 4, 5 and 7).

The support block 29 is pivoted, at 29a at one end of it, to the channel 9 so as to allow the rods 28 to rotate if the filter bags 1 get jammed in the infeed area of 5 the channel, thereby exerting on the rods 28 a downward pushing force that is greater than the retaining force exerted by the rods 28 on the walls 9a of the channel 9 (Figure 8 and arrow F28).

A presence sensor, labelled 31, associated with the channel 9 and located near the pair of rods 28 when they are parallel to the channel 9, generates a o machine 100 stop signal S when the rods 28 are rotated downwards.

The machine 100 described above works in the following manner.

Each single filter bag 1 present on the first drum 6t is individually released into a respective cell 20 in the second drum 8 as the two drums rotate concordantly (see Figure 1 and arrow F6). 5 Once the filter bag 1 has been received, the finger units 22 are closed over the cell 20 in order to hold in the filter bag 1 (see Figure 2).

As the second drum 8 rotates, each cell 20 is in turn aligned with the infeed

area of the channel 9; as each cell 20 approaches, the teeth 17 (held in the first pickup position) are positioned between the cell 20 and the filter bag 1 thanks to the presence of the grooves 21, and, at the same time, the finger units 22 move back to the open position (see Figure 3).

5 At this point, the teeth 17 are moved in the feed direction A in such a way as to push the filter bag 1 into the channel 9 (sse Figure 4). Here, the converging side walls 9a help keep the filter bag 1 in place.

The teeth 17 are then moved back to the pick-up position within the cell 20 which has just been cleared and is being held in the waiting position. Only then does i o the first drum 8 start turning again to perform another feed step.

When a certain number of filter bags 1 have been fed in, the lever 15 is activated to lift the filter bag Ia defining the separating element (or "flag") between two consecutive groups of filter bags 1 to be picked up manually (see Figure 1).

As the filter bags 1 are fed in, they form a continuous row of filter bags 1 15 which push each other along the channel 9 until they reach the conveyor belt 25 which receives and feeds them to the manual pickup-up and handling area 10.

If the filter bags 1 being fed into the channel 9 get jammed, so that the filter bag 1 at the infeed area prevents the filter bags 1 following it from advancing, the build up causes the teeth 17 to push the filter bags 1 until the force exerted on them

20 is sufficient to push the rods 28 downwards, thereby bringing the machine 100 to a stop.

A machine made as described above achieves the aforementioned aims thanks to an extremely simple end-of-line structure that is inexpensive to produce and yet capable of effectively feeding the filter bags at a fast and regular rate. 25 To this must be added the capability of dividing the filter bags into predetermined groups that are easy to distinguish and can be more easily picked up by hand or using suitable mechanical means.

The invention described can also be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the 3 o details of the invention may be substituted by technically equivalent elements.