Title of Invention	A DEVICE FOR SEALING LENGTHS OF FILTER PAPER
Abstract	A devicefor sealing filter bags for products for infusion where each filter bag is made from a flat web (1) of filter paper and has applied to it a tag (1b) and a transforming (1a) connecting the tag (1b) to the filter bag itself, comprises at least a sealing XXX element (3) positioned so that it faces a forst path (P) along whch the flat web (1) is fed and so as seal the string (1a) which is arrenged according to a defined pattarn and the tags (1b) to each other and to the first web (1) of filter paper drive means (4) for XXX to the sealing XXX means (3) a defined motion towards and away from a sending position the drive means (4) in turn comprising first means (5) actual upon by the sealing sonotrode element (3) and designed to apply to predetermined force (F) in the sealing sonotrode element (3) itself second means (6) for opposing the action of the first means (5) that is to say for reducing its innersity and third control means (7) for the second means (6) during predetermined steps of passing the filter bag components under the sealing sonotrode element (3) so as to predetermined sealing contact.

Title of Invention

A DEVICE FOR SEALING LENGTHS OF FILTER PAPER

Abstract

A devicefor sealing filter bags for products for infusion where each filter bag is made from a flat web (1) of filter paper and has applied to it a tag (1b) and a transforming (1a) connecting the tag (1b) to the filter bag itself, comprises at least a sealing XXX element (3) positioned so that it faces a forst path (P) along whch the flat web (1) is fed and so as seal the string (1a) which is arrenged according to a defined pattarn and the tags (1b) to each other and to the first web (1) of filter paper drive means (4) for XXX to the sealing XXX means (3) a defined motion towards and away from a sending position the drive means (4) in turn comprising first means (5) actual upon by the sealing sonotrode element (3) and designed to apply to predetermined force (F) in the sealing sonotrode element (3) itself second means (6) for opposing the action of the first means (5) that is to say for reducing its innersity and third control means (7) for the second means (6) during predetermined steps of passing the filter bag components under the sealing sonotrode element (3) so as to predetermined sealing contact.

Full Text	path and designed to attach the tie string and the tags to the filter paper web. The sealers, which are sonotrodes, perform a defined movement between a sealing position and a waiting position, and this movement; which is performed simultaneously and synchronously by all the sealers, is imparted, through a transmission element shared by all the sealers, by a second cam drive shaft connected to the same source of motion to which the first shaft that drives the conveyor drum is connected. In other words, the sonotrode is placed in a preferred position relative to the underlying part over which filter paper web movesj this preferred position depending on the inherent properties of the paper itself, on the speed at which it is fed and on the thickness of the components to be sealed (filter paper, tie string and tag) placed one over the other. The Applicant has found that the relative position between the emitting surface of the sonotrode and the product supporting surface constitutes a fundamental variable for good sealing quality. In practice, the constancy of sealing quality is directly proportional also to the force of the contact (besides contact time and the frequency of sonotrode activation) between the sonotrode and the product supporting surface, which means that the thrust force applied mist be as constant as possible. This is not always easy to achieve since the components to be sealed (described above) are not always exactly the same in thickness and their total thickness varies within quite a wide range: as a result, the pressure applied to the products that move into the sealing area (under the sonotrode) tends to vary from one product to the other, thus leading to irregular sealing quality. The present invention therefore has for an object to overcome the above mentioned drawback through a device that enables the sealer sonotrode to apply a substantially constant contact force on the product to be sealed, the application of the force being synchronised with the presence of the product in the sealing area. Disclosure of the invention WO 2005/007513 PCT/IB2004/002363 3 According to the invention, this object is achieved by a device for sealing filter bags for products for infusion comprising at least: a sealing sonotrode element positioned so that it faces a first path along which the flat web is fed and so as to seal the string, which is arranged according to a defined pattern, and the tags to each other and to the flat web of filter paper,- drive means for imparting to the sealing sonotrode means a defined motion towards and away from a sealing position; the drive means in turn comprising first means acted upon by the sealing sonotrode element and designed to apply a predetermined force to the sonotrode sealing element itself; second means for opposing the action of the first means, that is to say, for reducing its intensity, and third control means for disabling the second means, during predetermined steps of passing the filter bag components under the sealing sonotrode element, so as to permit a predetermined sealing contact. 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 partial side view, with some parts cut away to better illustrate others, of an apparatus for making filter bags for products for infusion equipped with the sealing device according to the present invention for wrapping groups of products with film; Figures 2 and 3 are, respectively, a side view and a front view, with some parts in cross section to better illustrate others, of a detail H of the device of Figure I. Detailed description of the preferred embodiments of the invention. WO 2005/007533 PCT/IB2004/002363 4 With reference to the accompanying drawings, in particular Figure 1, the device according to the invention is used to seal filter bags for products for infusion. Ey way of example, each filter bag is made from a flat web 1 of filter paper (shown by the dashed line in Figure l) and has applied to it a tag and a tie string connecting the tag to the filter bag itself. The device, denoted in its entirety by the numeral 2, may form part of a more complex machine for making the entire filter bags and filling them with product. Machines of this kind are very well known and will not be described here since they are described in detail in prior art, such as, for example, in patent application EO2002A00079B by the same Applicant as the present. The device 2 essentially comprises: - a sealer sonotrode 3 positioned BO that it faces a first path P along which the flat web 1 is fed (see arrow P in Figure 1) and so as to seal the string la, which is arranged according to a defined pattern, and the tags 1b to each other and to the flat web 1 of filter paper; - drive means 4 for imparting to the sealer sonotrode 3 a defined motion towards and away from a sealing position. As also illustrated in Figures 2 and 3, the drive means 4 comprise .- - first means 5 acted upon by the sealer sonotrode 3 and designed to apply a predetermined force P to the sealer sonotrode 3 itself (as indicated by the corresponding arrow in Figure 1); - second means 6 for opposing the action of the first means 5, that is to say, for reducing its intensity; - third control means 7 for disabling the second means 6 during predetermined steps of passing the filter bag components under the sealing sonotrode element 3, so as to permit a predetermined sealing contact. More specifically, in a preferred embodiment, the means 4 for driving the sealer sonotrode 3 may comprise a four-point linkage e driven -by cam means 3 (partially illustrated in' Figure 1) designed to move the working end of the sealer sonotrode 3 along a respective second closed path C comprising a sealing WO 2005/007513 PCT/IB2004/002363 5 section S that substantially coincides with the first path P, and a return section R extending outside the first path P. In this specific case, the first and second means 5 and 6 define a part of the four-point linkage 8. Looking in more detail (again with reference to Figures 2 and 3) , the first means 5 may consist of elastic means comprising a helical spring Sir. positioned on one of the arms 8a of the four-point linkage 8. The second means 6 may consist of a pneumatic cylinder 6c (for example, of the single acting type) defining the arm 8a of the four-point linkage 8 linked at one end to the sonotrode sealer 3 and at the other to the cam means 9. The cylinder 6 houses the helical spring 5m defining the first means 5 in such a way as to interact with the spring when the sealer sonotrode 3 moves along the aforementioned sections of its path. The aforementioned third control means 7 may comprise a unit 7a for charging and discharging fluid under pressure (for example air) into and out of the pneumatic cylinder 6c in such a way as to vary the intensity of the force F applied to the sealer sonotrode 3 according to the section of the second path C the sealer sonotrode 3 is moving along. In other words, the air is discharged from the cylinder 6 c (so that only the load F of the spring 5m, with a slight spring over travel, is applied) when the sealer sonotrode 3 is moving along the sealing section S whilst the cylinder 6c is charged with air during the idle, return section R of the path. It will be understood that the invention can be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements. WO 2005/007513 PCT/IB2004/O02363 6 Claims 1. A device for sealing filter bags for products for infusion; each filter bag being made from a flat web (1) of filter paper and having applied to it a tag and a tie string connecting the tag to the filter bag itself; the device (2) comprising at least: - one sealer sonotrode (3) positioned so that it faces a first path (P) along which the flat web (l) is fed so as to seal the string (la), which is arranged according to a defined pattern, and the tags (xb) to each other and to the flat web (1) of filter paper; - drive means (4) for imparting to the sealer sonotrode (3) a defined motion towards and away from a sealing position, the device being characterised in that the drive means (4) comprise: - first means (5) acted upon by the sealer sonotrode (3) and designed to apply a predetermined force (F) to the sealer sonotrode (3) itself; - second means (6) for opposing the action of the first means (5), that is to say, for reducing its intensity; - third control means (7) for disabling the second means (6) during predetermined steps of passing the filter bag components under the sealing sonotrode element (3) , so as to permit a predetermined sealing contact. 2." The device according to claim l, where the means (4) for driving the sealer sonotrode (3) comprise a four-point linkage (8) driven by cam means (9} designed to move the working end of the-sealer sonotrode (3) along a respective second closed path (C) comprising a sealing section (S) that substantially coincides with the first path (P), and a return section (R) extending outside the first path (P) , the device being characterised in that the f irst and second means (5, G) define a part of the four-point linkage (8) 3. The device according to claims 1 and 2, characterised in that the first means (5) are elastic means. 4. The device according to claims 2 and 3, characterised in that the elastic means (B) comprise a helical spring (5m) positioned on one of the arms (8a) of the four-point linkage (8). WO 2005/007533 PCT/IB2004/002363 7 5. The device according to claims 1 and 2, characterised in that the second means (6) consist of a pneumatic cylinder (6c) defining one of the arms (8a) of the four-point linkage (8) linked at one end to the sonotrode sealer (3) and at the other to the cam means (9) • 6. The device according to claims 1 and 2, characterised in that the second means (6) consist of a pneumatic cylinder (6c) defining one of the arms (8a) of the four-point linkage (8) linked at one end to the sonotrode sealer (3) and at the other to the cam means (3); the cylinder (6) housing the first means (5) consisting of a helical spring (5m). 7. The device according to claims 1, 2 and 6, characterised in that the third control means (7) comprise a unit (7a) for charging and discharging a fluid under pressure into and out of the pneumatic cylinder (6c) in such a way as to vary the intensity of the force (F) applied to the sealer sonotrode (3) according to the section of the second _ path (C) the sealer sonotrode (3) is moving along. A devicefor sealing filter bags for products for infusion where each filter bag is made from a flat web (1) of filter paper and has applied to it a tag (1b) and a transforming (1a) connecting the tag (1b) to the filter bag itself, comprises at least a sealing XXX element (3) positioned so that it faces a forst path (P) along whch the flat web (1) is fed and so as seal the string (1a) which is arrenged according to a defined pattarn and the tags (1b) to each other and to the first web (1) of filter paper drive means (4) for XXX to the sealing XXX means (3) a defined motion towards and away from a sending position the drive means (4) in turn comprising first means (5) actual upon by the sealing sonotrode element (3) and designed to apply to predetermined force (F) in the sealing sonotrode element (3) itself second means (6) for opposing the action of the first means (5) that is to say for reducing its innersity and third control means (7) for the second means (6) during predetermined steps of passing the filter bag components under the sealing sonotrode element (3) so as to predetermined sealing contact.

Full Text

path and designed to attach the tie string and the tags to the filter paper web. The sealers, which are sonotrodes, perform a defined movement between a sealing position and a waiting position, and this movement; which is performed simultaneously and synchronously by all the sealers, is imparted, through a transmission element shared by all the sealers, by a second cam drive shaft connected to the same source of motion to which the first shaft that drives the conveyor drum is connected.
In other words, the sonotrode is placed in a preferred position relative to the underlying part over which filter paper web movesj this preferred position depending on the inherent properties of the paper itself, on the speed at which it is fed and on the thickness of the components to be sealed (filter paper, tie string and tag) placed one over the other.
The Applicant has found that the relative position between the emitting surface of the sonotrode and the product supporting surface constitutes a fundamental variable for good sealing quality.
In practice, the constancy of sealing quality is directly proportional also to the force of the contact (besides contact time and the frequency of sonotrode activation) between the sonotrode and the product supporting surface, which means that the thrust force applied mist be as constant as possible. This is not always easy to achieve since the components to be sealed (described above) are not always exactly the same in thickness and their total thickness varies within quite a wide range: as a result, the pressure applied to the products that move into the sealing area (under the sonotrode) tends to vary from one product to the other, thus leading to irregular sealing quality.
The present invention therefore has for an object to overcome the above mentioned drawback through a device that enables the sealer sonotrode to apply a substantially constant contact force on the product to be sealed, the application of the force being synchronised with the presence of the product in the sealing area.
Disclosure of the invention

WO 2005/007513 PCT/IB2004/002363
3
According to the invention, this object is achieved by a device for sealing filter bags for products for infusion comprising at least: a sealing sonotrode element positioned so that it faces a first path along which the flat web is fed and so as to seal the string, which is arranged according to a defined pattern, and the tags to each other and to the flat web of filter paper,- drive means for imparting to the sealing sonotrode means a defined motion towards and away from a sealing position; the drive means in turn comprising first means acted upon by the sealing sonotrode element and designed to apply a predetermined force to the sonotrode sealing element itself; second means for opposing the action of the first means, that is to say, for reducing its intensity, and third control means for disabling the second means, during predetermined steps of passing the filter bag components under the sealing sonotrode element, so as to permit a predetermined sealing contact.
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 partial side view, with some parts cut away to better illustrate others, of an apparatus for making filter bags for products for infusion equipped with the sealing device according to the present invention for wrapping groups of products with film;
Figures 2 and 3 are, respectively, a side view and a front view, with some parts in cross section to better illustrate others, of a detail H of the device of Figure I.
Detailed description of the preferred embodiments of the invention.

WO 2005/007533 PCT/IB2004/002363
4
With reference to the accompanying drawings, in particular Figure 1, the device according to the invention is used to seal filter bags for products for infusion.
Ey way of example, each filter bag is made from a flat web 1 of filter paper (shown by the dashed line in Figure l) and has applied to it a tag and a tie string connecting the tag to the filter bag itself.
The device, denoted in its entirety by the numeral 2, may form part of a more complex machine for making the entire filter bags and filling them with product. Machines of this kind are very well known and will not be described here since they are described in detail in prior art, such as, for example, in patent application EO2002A00079B by the same Applicant as the present.
The device 2 essentially comprises:
- a sealer sonotrode 3 positioned BO that it faces a first
path P along which the flat web 1 is fed (see arrow P in Figure 1)
and so as to seal the string la, which is arranged according to a
defined pattern, and the tags 1b to each other and to the flat web
1 of filter paper;
- drive means 4 for imparting to the sealer sonotrode 3 a
defined motion towards and away from a sealing position.
As also illustrated in Figures 2 and 3, the drive means 4 comprise .-
- first means 5 acted upon by the sealer sonotrode 3 and
designed to apply a predetermined force P to the sealer sonotrode
3 itself (as indicated by the corresponding arrow in Figure 1);
- second means 6 for opposing the action of the first means
5, that is to say, for reducing its intensity;
- third control means 7 for disabling the second means 6
during predetermined steps of passing the filter bag components
under the sealing sonotrode element 3, so as to permit a
predetermined sealing contact.
More specifically, in a preferred embodiment, the means 4 for driving the sealer sonotrode 3 may comprise a four-point linkage e driven -by cam means 3 (partially illustrated in' Figure 1) designed to move the working end of the sealer sonotrode 3 along a respective second closed path C comprising a sealing

WO 2005/007513 PCT/IB2004/002363
5
section S that substantially coincides with the first path P, and a return section R extending outside the first path P.
In this specific case, the first and second means 5 and 6 define a part of the four-point linkage 8.
Looking in more detail (again with reference to Figures 2 and 3) , the first means 5 may consist of elastic means comprising a helical spring Sir. positioned on one of the arms 8a of the four-point linkage 8.
The second means 6 may consist of a pneumatic cylinder 6c (for example, of the single acting type) defining the arm 8a of the four-point linkage 8 linked at one end to the sonotrode sealer 3 and at the other to the cam means 9.
The cylinder 6 houses the helical spring 5m defining the first means 5 in such a way as to interact with the spring when the sealer sonotrode 3 moves along the aforementioned sections of its path.
The aforementioned third control means 7 may comprise a unit 7a for charging and discharging fluid under pressure (for example air) into and out of the pneumatic cylinder 6c in such a way as to vary the intensity of the force F applied to the sealer sonotrode 3 according to the section of the second path C the sealer sonotrode 3 is moving along.
In other words, the air is discharged from the cylinder 6 c (so that only the load F of the spring 5m, with a slight spring over travel, is applied) when the sealer sonotrode 3 is moving along the sealing section S whilst the cylinder 6c is charged with air during the idle, return section R of the path.
It will be understood that the invention can be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements.

WO 2005/007513 PCT/IB2004/O02363
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Claims
1. A device for sealing filter bags for products for infusion; each filter bag being made from a flat web (1) of filter paper and having applied to it a tag and a tie string connecting the tag to the filter bag itself; the device (2) comprising at least:
- one sealer sonotrode (3) positioned so that it faces a first
path (P) along which the flat web (l) is fed so as to seal the
string (la), which is arranged according to a defined pattern, and
the tags (xb) to each other and to the flat web (1) of filter
paper;
- drive means (4) for imparting to the sealer sonotrode (3) a
defined motion towards and away from a sealing position, the
device being characterised in that the drive means (4) comprise:
- first means (5) acted upon by the sealer sonotrode (3) and
designed to apply a predetermined force (F) to the sealer
sonotrode (3) itself;
- second means (6) for opposing the action of the first means
(5), that is to say, for reducing its intensity;
- third control means (7) for disabling the second means (6)
during predetermined steps of passing the filter bag components
under the sealing sonotrode element (3) , so as to permit a
predetermined sealing contact.
2." The device according to claim l, where the means (4) for driving the sealer sonotrode (3) comprise a four-point linkage (8) driven by cam means (9} designed to move the working end of the-sealer sonotrode (3) along a respective second closed path (C) comprising a sealing section (S) that substantially coincides with the first path (P), and a return section (R) extending outside the first path (P) , the device being characterised in that the f irst and second means (5, G) define a part of the four-point linkage (8)
3. The device according to claims 1 and 2, characterised in that
the first means (5) are elastic means.
4. The device according to claims 2 and 3, characterised in that
the elastic means (B) comprise a helical spring (5m) positioned on
one of the arms (8a) of the four-point linkage (8).

WO 2005/007533 PCT/IB2004/002363
7
5. The device according to claims 1 and 2, characterised in that
the second means (6) consist of a pneumatic cylinder (6c) defining
one of the arms (8a) of the four-point linkage (8) linked at one
end to the sonotrode sealer (3) and at the other to the cam means
(9) •
6. The device according to claims 1 and 2, characterised in that
the second means (6) consist of a pneumatic cylinder (6c) defining
one of the arms (8a) of the four-point linkage (8) linked at one
end to the sonotrode sealer (3) and at the other to the cam means
(3); the cylinder (6) housing the first means (5) consisting of a
helical spring (5m).
7. The device according to claims 1, 2 and 6, characterised in
that the third control means (7) comprise a unit (7a) for charging
and discharging a fluid under pressure into and out of the
pneumatic cylinder (6c) in such a way as to vary the intensity of
the force (F) applied to the sealer sonotrode (3) according to the
section of the second _ path (C) the sealer sonotrode (3) is moving
along.
A devicefor sealing filter bags for products for infusion where each filter bag is made from a flat web (1) of filter
paper and has applied to it a tag (1b) and a transforming (1a) connecting the tag (1b) to the filter bag itself, comprises at least a sealing
XXX element (3) positioned so that it faces a forst path (P) along whch the flat web (1) is fed and so as seal the string (1a)
which is arrenged according to a defined pattarn and the tags (1b) to each other and to the first web (1) of filter paper drive means
(4) for XXX to the sealing XXX means (3) a defined motion towards and away from a sending position the drive means (4)
in turn comprising first means (5) actual upon by the sealing sonotrode element (3) and designed to apply to predetermined force (F)
in the sealing sonotrode element (3) itself second means (6) for opposing the action of the first means (5) that is to say for reducing
its innersity and third control means (7) for the second means (6) during predetermined steps of passing the filter bag
components under the sealing sonotrode element (3) so as to predetermined sealing contact.

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Patent Number

216860

Indian Patent Application Number

01671/KOLNP/2005

PG Journal Number

12/2008

Publication Date

21-Mar-2008

Grant Date

19-Mar-2008

Date of Filing

22-Aug-2005

Name of Patentee

I.M.A INDUSTRIA MACCHINE AUTOMATICHE S.P.A.

Applicant Address

VIA EMILIA LEVANTE, 428-442, I-40064 OZZANO EMILIA (BOLOGNA) ITALY

Inventors:

#	Inventor's Name	Inventor's Address
1	CAROLI, RODOLFO	VIA CORRECCHIELLO, 14, I-40026 IMOLA ITALY

PCT International Classification Number

B65B 29/04

PCT International Application Number

PCT/IB2004/002363

PCT International Filing date

2004-07-15

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	03425488.8	2003-07-21	EUROPEAN UNION