EP2572996B1 - Method and device for producing bags - Google Patents

Description

The present invention relates to a method and an apparatus for producing bags, in particular for the production of infusion bags.

The present invention is based in particular on a method as known from the EP-A2-0 771 730 is known. In this method, a flat web initially supplied as a flat web is longitudinally folded to form a web closed on one side by a fold. Thereafter, in this prior art by welding, separate chambers are separated in the one-sided closed path. The chambers are further provided as parts of the one-piece track. With the chamber opening up these chambers are then filled at a filling station. For this purpose, good is filled into the chambers in the chambers open on the upper side. Continuing upright, the web is subsequently fed to a sealing device, in which also the upper side of the bags, ie the side opposite the fold, is closed.

In this prior art method, the well-sealed bags continue to be promoted as part of a continuous web. By reorienting the web, the bags are deposited with their side surface on a storage path, to finally also fed as a continuum of a cutting device. This cutting device comprises a rotating knife, which acts from above against the storage path such that the film web is separated in the region of a section dividing the successive chambers seam. This separation makes bags available regardless of the lane. The separate bags fall on a conveyor line, from where they are discharged from the device.

The previously known method is relatively complicated, since conveyor lines are required in order to carry out the individual method steps at stations suitable for this purpose.

In the from the WO-A-1999/59875 Known methods, the closed at the opposite side of the fold chambers are deflected from an initially vertical extension for filling the chambers in a horizontal orientation and only after a separation of the bags by cutting with subsequent separation takes place. The closing of the bags in the continuum, ie as part of the endlessly supplied bag material limited on the one hand, the filling amount, since the endless web under tension is guided over the various stations, that is also promoted under tension along a filling station and a sealing station. Furthermore, a weld closing the bag material on the side opposite the fold can only be formed parallel to the fold, ie in the conveying direction of the continuous web.

A method with the preamble features of claim 1 and an apparatus with the preamble of claim 6 is known from WO-A-2007/089838 known. In the previously known method, a flat web is closed by a fold on the underside to create a folded web. The folded web is fed to a studded welding wheel to provide the web with chambers. Prepared in this way, the web leaves as a continuum a seal module. The web is fed to a filling module. First, the continuum in a knife module is cut by rotating knives. The bags which have been separated in this way on the top side are conveyed away from the knife module by a conveyor belt with suction heads and fed to gripping devices which circulate in a circular path. The gripping means have a pivotable jaw and a rigid jaw, which each hold the bag at its leading and trailing vertical longitudinal sides, ie those sides which are separated by a vertical separating seam. The at least one clamping jaw is pivotable about an axis which extends approximately parallel to the axis of rotation of a filling wheel, at the periphery of which the bags are held and filled by the gripping devices. The pivoting movement of the at least one jaw serves to open the bag. Due to the pivoting movement of the at least one clamping jaw, the side edges of the bag come closer together. The opposite side walls must inevitably bulge. As a result, the bags are opened on the top side, so that a funnel can be introduced into the bags.

The gripping devices grip the bags each below their inlet opening. After filling, this area is sealed between two welding jaws of a welding device, resulting in closed bags. This welding also takes place on the outer circumference of the filling wheel. Thereafter, the individual bags are gripped by suction arms, which are arranged on the outer periphery of a rotating Ausförderrades and which grip the bags held between the last pressure rollers there and eject them from the circular movement along the circumference of the filling wheel.

The from the WO-A-2007/089838 previously known device leaves nothing to be desired. The individual, provided at different locations modules lead to a relatively bulky configuration. Also, the web material between the individual modules must be performed and handed over, which requires additional effort.

The US-A-3 473 294 discloses the production of bags from a flat web, which is first folded and then divided by transverse welds in chambers. Thus prepared the chambers are separated. Thereafter, the individual bags thus formed are still held by gripping devices that have been driven under the continuum. The omission of the continuum is compensated by a guide, which limits the bags on the upper side. Via a further linear movement, the bags open on one side are fed to the filling station. On the way back of this revolving movement, the bags open on one side are closed and finally discharged at the second turning point of the circulating conveyor line.

The WO 2008/102250 relates to a welding device with two rotating elements, each forming the sonotrode and the anvil, the sonotrode and the anvil being mutually engaged to form a bag.

The production of infusion bags in tetrahedral form is for example WO-A-95/01907 and EP-A-1549548 known.

The present invention is based on the problem to provide an improved method and an apparatus for producing bags, which can be carried out in particular space-saving and thus easier. In particular, the present invention has the production of infusion bags, ie bags containing infusible material in view. In particular, the present invention seeks to provide the WO-A-2007/089838 modify known methods so that they can be produced with this infusion bag in tetrahedral form and specify a corresponding device.

To solve the procedural problem, the present invention proposes a method having the feature of claim 1. In this, a separating seam is formed between adjacent combs, by which the individual bags are separated from the flat web, and the chambers are filled after forming the cutting seam with the material. Accordingly, in the method according to the invention, a separating seam is initially formed, via which the bags are separated. at In the method according to the invention, the continuum formed by the flat track is interrupted before the chambers are filled in such a way that the individual bags can be separated without a separate method step acting on the material of the flat web without cutting or separating. When separating the side distance of the first run as a continuum chambers is increased, ie the chambers no longer border directly to each other with substantially touching side edges.

In this case, a method having the features of claim 1 is also realized if after forming the cutting seam the chambers then formed in the manner of a continuum, d. H. be guided with substantially adjacent side surfaces. It is only the fact that after filling no separation process has to be done, but the chambers forming the individual bags before or after or during the closing of the opposite side of the fold by a relative movement, where appropriate, the chambers by tearing in the area the separating seam are separated from each other.

With a view to the production of tetrahedral bags, it is proposed according to the invention to close the open-sided bags on the side opposite the fold with a weld seam which extends substantially at right angles to the fold. Accordingly, scattered, d. H. welded with their edges no longer abutting bags, via a weld, which extends substantially perpendicular to the fold, whereby a tetrahedral bag is formed.

For this purpose, according to the invention, the bags which are open on one side are pivoted prior to closing in such a way that the fold is aligned substantially at right angles to the advancing direction of the bag. In the process of the invention, the bags are basically rotated about their own axis, while at the same time they are preferably pivoted on an approximate circular path from the station for forming the chambers to the discharge of the finished bag, ie about a common pivot point. Usually, the bags are thereby pivoted about their own axis during filling, but anyway, a filling tube for filling the bags is introduced during the pivoting in the bags. By this measure, the distance over the various stations to the discharge of the finished bag and thus reduce the processing time.

According to a preferred development of the present invention, it is proposed to continuously move the material constituting the pouches at least from the formation of the fold to closing on the side opposite the fold. In the method according to the invention, this continuous movement is preferably a movement about a pivot point. In this case, certain components of motion can also take place in the radial direction, so that the movement of the material is only approximately a circular movement. In particular, in the context of the movement about a pivot point of the radial distance starting from an inlet region in which the unilaterally closed with a fold path of the processing path for forming chambers, to a station, wherein the material on the opposite side of the fold to Formation of a closed bag is closed, easily enlarged. Thus, the possibility is provided to provide an anvil of a welding device between a path leading the driving wheel and the web material, which is effective in closing the opposite side of the fold.

According to a preferred embodiment of the present invention, the bag-forming material is gripped and conveyed by a gripping device associated with a single bag prior to forming the cut seam until it closes on the opposite side of the fold until the bag closes on the side opposite the pleat is made. In this case, usually more gripping means are simultaneously engaged, each of the gripping means being associated with a single bag, ie a single length corresponding to a bag length of the web to be conveyed. In other words, a plurality of gripping devices each engage between the individual compartments dividing departments, which are regularly formed by transverse welds. The gripping device is usually effective before forming the chambers, ie engages the fold before forming the chamber. The release of this intervention is usually carried out immediately after closing the finished bag. The gripping by the gripping devices is further preferably carried out in that the gripping device engages the material of the web only in the region of the fold, but otherwise leaves the volume provided above the fold and usually between the chamber distributions unimpaired. In other words, despite engaging gripping means, the chamber can be filled up to or nearly to the bottom formed by the fold.

According to a preferred embodiment of the present invention unilaterally open bags are isolated. On one side open bags are at three usually perpendicular to each other extending sides interconnected portions of the double-layered web, on the one hand by the fold and at their perpendicular thereto extending ends through the department, d. H. Transverse welds are closed. The bags are separated. These bags are filled, preferably during singulation. This preferred development offers the possibility of an effective chamber filling, since an interaction of adjacent chambers during filling is no longer present.

To solve the device aspect, the present invention proposes a device having the feature of claim 6. This device has a folding device for folding a flat web, as for example from the WO-A-1999/059 875 A1 or the EP-A2-0 771 730 or the WO-A-2007/089838 is known. Furthermore, the device has a gripper assembly which grips the folded web and has a multiplicity of gripping devices which are moved around a pivot point and are each pivotally mounted for gripping the fold. By this pivoting, the gripping device grips the web in the region of the fold. In particular, before dividing the chamber, the supplied endless material is drawn and conveyed by one or more gripping devices in the direction of the various processing stations for dividing the chambers, filling and closing the bags. The apparatus further comprises a bag-end welder comprising a toothed, rotating anvil wheel and a sonotrode cooperating with teeth of the projecting anvil wheel to form chambers to form a parting seam provided between the chambers. The toothed anvil wheel has the division of the individual chambers correspondingly spaced projections, which each form an anvil for dividing the chambers.

Furthermore, the device according to the invention has a rotating metering plate with a feed side for applying the bag contents and an opposite feed side from which protrudes a plurality of filling tubes, which are penetratable into the chambers. Consequently, a filling tube is introduced into each of the chambers. The axis of rotation of the metering plate is inclined to the axis of rotation of the anvil wheel, so that the filling tubes penetrate due to the inclination over a certain angle section of the chambers located on the outer circumference of the anvil wheel in these and inevitably be pulled out of the chambers due to the inclination. It does not matter whether the chambers are still provided in the continuum, ie moved with substantially touching side edges, or are already isolated, ie the respective filling tubes engage in individual bags. Accordingly, the metering plate may alternatively or cumulatively also be aligned with respect to its axis of rotation obliquely to a rotational axis of the gripper assembly. The device according to the invention also has a welding device for closing the bags on the side opposite the fold and a discharge device for conveying out the bags. This ejector moves the bags regularly in the radial direction relative to the direction of rotation of the anvil wheel and / or the gripper assembly. The discharge can For example, by means of air pressure or a driver, which is moved for example in the radial direction and / or perpendicular to the axis of rotation of the anvil wheel.

According to a preferred embodiment of the present invention, the sonotrode is stationary and aligned obliquely to the anvil protrusions. The sonotrode has an effective length that at least covers the width of the folded web. Regularly, the tooth projections of the anvil wheel are formed so that they the folded web transversely to its longitudinal direction, d. H. tower on both sides in the width direction. The sonotrode and the anvil are matched to one another such that initially a transverse weld seam is formed as the end face of the tooth projections on the sonotrode approaches, while the material of the track between the sonotrode and the end face of the tooth projection is provided with a separating seam at a minimum distance and in the course of the further pivoting movement, d. H. is again formed directly adjacent to the seam with a transverse weld seam with increasing radial gap. The dividing seam then passes through two adjacently provided transverse weld seams delimiting the chambers. The inclination of the sonotrode relative to the substantially axial extent of the tooth projections causes a gentle treatment of the supplied material. The formation of the cutting seam is carried out only under the local heating in the longitudinal direction. As the pivoting movement increases, this point migrates in an axial direction such that the forming of the parting seam does not occur in one over the entire width of the web, but the frictional heat introduced axially into the web material from one end of the web material in the width direction to form the dividing seam the other one wanders.

According to a preferred development of the present invention, the sealing device for closing the bags has a fixed anvil which is arranged between the anvil wheel and a sonotrode. The sonotrode is, in particular, a rotating sonotrode whose outer peripheral surface interacts with the anvil.

According to a preferred embodiment, the gripping device is pivotally mounted on a gripper base, which supports at least two folding arms acting on the open end of the bag pivotable. The folding arms are usually mounted on a four-bar mechanism and preferably operated so that they interact on both sides with the open end of the bag and act on this, to each other Prior to closing the surfaces of the bag against each other before the bag is made by closing on the opposite side of the fold.

To produce a radial distance between the anvil wheel and the individual bags, the gripping devices in the gripper arrangement are mounted so as to be movable in a translatory manner. Thus, the individual, held by the gripping means bags are not only pivoted about the pivot point of the gripper assembly, but simultaneously moved radially translationally to the outside.

According to a preferred embodiment, which may be essential to the invention, a metering device and a weighing device is arranged on the task side of the metering plate. The metering arrangement emits a mass flow in the direction of the feed side, which initially strikes the weighing device and is detected there. The weighing device and the metering device are connected in terms of control via a controller which compares an actual value of the mass flow detected by the weighing device with a desired value and controls the mass flow delivered by the metering device on the basis of this comparison. This controlled system ensures that essentially a constant mass flow is deposited on the feed side of the metering plate. The removal of the mass flow is usually carried out in the form of a Gutstreifens, which is provided on the metering plate on the radially inner side relative to an opening of the filling tubes. Assigned to the task side of the metering plate is usually provided a scraper, which is fixedly mounted and relatively movable to the rotating metering plate and which pushes out the deposited on the feed side and rotationally moving material radially outwards and into the mouths to the filling tubes.

The preferred development with a controlled system between the metering device and the weighing device offers the possibility, in particular in the case of infusible material, of compensating specifically for tea effects which are due to segregation. At a constant volumetric flow rate of infused infusible material, this segregation results in a higher mass flow of an initial, lower contents of the metering device as compared to discharging the overhead contents, as the density changes due to segregation in filling level and in the lower part of a conveying hopper or tower Bulk material with a higher density is present than in the upper part. Consequently, justified variations in the bulk density can be compensated by the controlled system in the nature of the goods.

Figur 1

eine schematische Darstellung wesentlicher Stationen eines ersten Ausführungsbeispiels der vorliegenden Erfindung;

Figur 2

eine perspektivische Darstellung eines Ambossrades mit zugeordneter Sonotrode zum Abschweißen von Tüten eines zweiten Ausführungsbeispiels;

Figur 3

eine perspektivische Darstellung des zweiten Ausführungsbeispiels ähnlich Figur 2 mit einem Dosierteller;

Figur 4

der in Figur 3 gezeigte Dosierteller in einer Draufsicht mit Teilen einer Dosiervorrichtung;

Figur 5

eine Darstellung des zweiten Ausführungsbeispiels ähnlich zu Figur 3 für einen anderen Umfangsabschnitt des Ambossrades mit einer Schweißeinrichtung zum Verschließen der Tüten;

Figur 6

eine Darstellung des zweiten Ausführungsbeispiels ähnlich zu Figur 3 mit einer Greiferanordnung;

Figur 7A

eine perspektivische Darstellung einer Greifeinrichtung der Greiferanordnung nach Figur 6 in einer Ausgangstellung;

Figur 7B

eine perspektivische Darstellung der Greifeinrichtung nach Figur 7A in einer klemmenden Stellung;

Figur 7C

eine perspektivische Darstellung der Greifeinrichtung nach Figur 7A in einer die Tüte um eine im Wesentlichen horizontale Achse schwenkenden Stellung;

Figur 7D

eine perspektivische Darstellung der Greifeinrichtung nach Figur 7A kurz vor Beendigung der Schwenkbewegung um eine im Wesentlichen horizontale Achse;

Figur 7E

eine perspektivische Darstellung der Greifeinrichtung nach Figur 7A nach Beendigung der Schwenkbewegung um eine im Wesentlichen horizontale Achse und zu Beginn des Umfaltens der Tüte;

Figur 7F

eine perspektivische Darstellung der Greifeinrichtung nach Figur 7A beim Umfalten der Tüte;

Figur 7G

eine perspektivische Darstellung der Greifeinrichtung nach Figur 7A am Ende des Umfaltens;

Figur 8

eine Draufsicht auf die Unterseite der in Figur 6 gezeigten Komponenten des zweiten Ausführungsbeispiels; und

Figur 9

eine vergrößerte perspektivische Darstellung eines Umfangsabschnittes des Ambossrades des zweiten Ausführungsbeispiels mit den verschlossenen Beuteln.

Further details and advantages of the present invention will become apparent from the following description of two embodiments in conjunction with the drawings. In this show:

FIG. 1

a schematic representation of essential stations of a first embodiment of the present invention;

FIG. 2

a perspective view of an anvil wheel with associated sonotrode for welding off bags of a second embodiment;

FIG. 3

a perspective view of the second embodiment similar FIG. 2 with a dosing plate;

FIG. 4

the in FIG. 3 dosing plate shown in a plan view with parts of a dosing device;

FIG. 5

a representation of the second embodiment similar to FIG. 3 for another peripheral portion of the anvil wheel with a welding device for closing the bags;

FIG. 6

a representation of the second embodiment similar to FIG. 3 with a gripper assembly;

FIG. 7A

a perspective view of a gripping device of the gripper assembly according to FIG. 6 in a starting position;

FIG. 7B

a perspective view of the gripping device after FIG. 7A in a pinching position;

FIG. 7C

a perspective view of the gripping device after FIG. 7A in a position pivoting the bag about a substantially horizontal axis;

Figure 7D

a perspective view of the gripping device after FIG. 7A shortly before the end of the pivotal movement about a substantially horizontal axis;

Figure 7E

a perspective view of the gripping device after FIG. 7A upon completion of the pivotal movement about a substantially horizontal axis and at the beginning of refolding of the bag;

FIG. 7F

a perspective view of the gripping device after FIG. 7A when folding the bag;

FIG. 7G

a perspective view of the gripping device after FIG. 7A at the end of refolding;

FIG. 8

a top view of the bottom of in FIG. 6 shown components of the second embodiment; and

FIG. 9

an enlarged perspective view of a peripheral portion of the anvil wheel of the second embodiment with the sealed bags.

In FIG. 1 Reference numeral 2 denotes a flat track, which is subtracted from a supply roll 4. The flat web consists of a water-permeable braid and is fed to a folding device 6, in which the flat web 2 is formed by forming a lower-side fold 8 to a closed web 10 by folding. Via a deflection roller 12, the underside closed web 10 of a rotating welding device 14 is supplied. This welding device 14 has distributed on the circumference of two welding rollers 16, 18 and cooperating welding jaws 17; 19, which are brought to cooperate by rotation of the welding rollers 16, 18, so that each enclosing the web 10 closed at the bottom, a transverse weld is formed, with successive transverse welds separating chambers between them.

Subsequent to the rotating welding device 14, a nozzle 20 is provided, which pulses like a pulse into the individual now divided-off chambers in order to open them. A separating device 22 now separates the open-topped bags 30. This separating device 22 may be formed by a knife acting from the underside, which cyclically acts on the web 10 in order to divide the individual bags 30. While these bags are already cut free with their leading end and with its rear end still attached to the web, the leading end is with a gripping device 24 gripped. This gripping device 24 comprises two circumferential bands 26, to which at approximately the transverse spacing of the transverse weld seams holding webs 28 are fastened, whose side clearance from each other is dimensioned such that they can clamp the double-layered material of the web between them. In such a way isolated and top-open bags 30, which are clamped with their leading and trailing end respectively between the retaining webs 28, now a filling tube 32 emerges. This filling tube 32 is dimensioned with respect to the bag 30, which after releasing the bag 30 by the gripping device 24, the bag 30 can be supported and guided vertically standing on a movement path 34.

On the trajectory, the bags 30 are filled via the filling tube 32 and preferably at the same time rotated by 90 °, so that the fold 8 is now perpendicular to the direction of movement.

The free open ends of the bags 30 are subsequently formed over a gate 36, so that the edges of the bags at right angles to the edge 8 together. Prepared in such a way, these edges are now welded to a welding device 38. As a result, a tea bag 40 in tetrahedral form is discharged from the production line.

The FIGS. 2 to 9 illustrate a second embodiment of a device according to the invention, wherein in FIG. 2 some parts of the device are omitted, so that FIG. 2 merely illustrates the path of a already simply folded web marked with reference numeral 10. FIG. 2 discloses a Tütenabschweißeinrichtung marked with reference numeral 100, which includes a toothed anvil 110, on the periphery of a plurality of projections 112 are arranged, which are connected via a common foot 114 with the otherwise cylindrical outer periphery of the anvil 110. The end face of the protrusions 112 has a geometric configuration corresponding to all protrusions 112 in the plan view of an enveloping surface. However, the end face of the projections 112 can just as well be more convexly curved than this envelope surface. The concrete contour of the end face of the projections 112 depends on the material properties of the flat web 2 forming the web 10 and on parameters of a sonotrode designated by reference numeral 116.

How out FIG. 2 in any case, the underside closed web 10 is deflected via a Umlenkabrolle and supplied to the anvil wheel 110 so that the web 10 is applied substantially tangentially to the end face of the projections 112. In this case, gripping devices still to be described below access the track 10 and pull it in the direction of rotation of the anvil wheel 110. In any case, the web 10 extends in the region of the sonotrode 116 substantially in a straight line between the end faces of the projections 112, wherein said gripping device lies radially within an imaginary envelope surface around the projections 112 and accordingly does not collide with the sonotrode 116.

The protrusions 112 have a greater height than the underside closed web 10. Accordingly, the web 10 protruding lengths of the protrusions 112 above and below the web 10 can be seen. The sonotrode 116 has a sonotrode head 118 whose length in the extension direction of a rotation axis 120 of the ambidextrous 110 substantially corresponds to the length of the projections 112 in this direction. The sonotrode head 118 has a substantially rectangular active surface, which can be arranged opposite the front side of the projections 112. However, this active surface is arranged obliquely relative to the end face of the projections 112, so that the active surface of the sonotrode 116 at no time covers the entire counter surface formed by the projections 112. Accordingly, the vibration caused by the sonotrode 116 acts only on a small length of the path 10 provided between the sonotrode 116 and the associated projection 112, the length extending in the direction of the axis of rotation 120.

The smallest distance between the sonotrode head 118 and the end face of the projection 112 is dimensioned so that the double-lying material of the web 10 is severed by the oscillating head of the sonotrode 116, whereas adjacent thereto, arranged between the end face of the projections 112 and the sonotrode 116 surface areas of Web 110 are sealed by welding, without a significant weakening of the material of the web 10 occurs. Accordingly, after passing through the sonotrode 116 at the level of the projections 116, the web 10 closed by folding on the underside each has a separating seam 124 through which the web 10 is separated into longitudinal sections corresponding to the width of the bags to be formed, as well as transverse welds arranged on either side of the separating seam 124 126. The cutting seam 124 can thereby be formed so that only a certain, acting on the separating seam 124 tensile force the individual lengths of the sections formed by the Querabschweißungen 126, only still unclosed bags 30 are actually separated from each other. After passing through the Tüteabschweißeinrichtung 100, the bags 30 thus formed continue to be guided substantially on the outer periphery of the anvil wheel 110. In addition, the individual bags 30 are pivoted about their central longitudinal axis until the initially tangential between the end faces of individual projections 112 extending fold 8 is arranged radially to the axis of rotation 120 of the anvil wheel 110 (see. FIG. 2 , in the direction of rotation of the anvil wheel 110 last bag 30).

FIG. 3 shows a perspective top view of the in FIG. 2 shown front peripheral portion of the anvil wheel 110, wherein in addition to the in FIG. 2 a circular metering plate 200 indicated by reference numeral 200 is shown, which has a plurality of filling tubes 210 in the circumferential direction, whose pitch substantially corresponds to the pitch of the anvil wheel 110 and which project from a feed side 220 of the metering plate 200. On a in plan view FIG. 3 Upper task page 225, the metering plate 100 leading to the filling tubes 210, flush with the task side 225 of the there level metering plate 200 opening funnel openings 230, which are arranged with a small circumferential distance relative to each other.

The filling tubes 210 are chamfered at their free end and accordingly formed to taper to a point. As FIG. 3 Furthermore, an axis of rotation of the metering plate 200 indicated by reference numeral 240 is set at an angle relative to the axis of rotation 120 of the anvil wheel 110. In this case, the axis of rotation 120 of the anvil wheel 110 or the axis of rotation 240 of the metering plate 200 may extend in the vertical direction. In any case, the dosing plate 200 is only inclined relative to the vertical with its axis of rotation 240 in such a way that contents deposited on the feed side 225 do not slip. Due to the inclination between the axis of rotation 120 of the anvil wheel 110 and the axis of rotation 240 of the metering plate 200, the filling tubes 210 dive into the bags 30 only over a certain peripheral portion relative to the circumference of the anvil wheel 110. The relative movement between the filling tubes 210 and the bags 30 in this preferably strictly vertical direction is solely dependent on the degree of inclination between the two axes 120, 240.

On the task side 225 of the dosing plate 200 is a designated by reference numeral 250 weighing device ( FIG. 4 ) with a conveyor belt 242, which is arranged with its feed end below a metering device 260, namely under an outlet tube 262 of the metering device 260, which comprises a driven screw 264 which projects into a metering funnel 266 and into the outlet tube 262. The end of the conveyor belt 252 opposite the feed end ejects a material continuously fed onto the conveyor belt 252 onto the surface of the metering plate 200, between the hopper openings 230 and a sliding element 268 stationarily associated with the weighing device 250 and its effective sliding surface from the weighing device 250 is arranged radially outward and finally ends at the level of the funnel openings 230.

The drive of the worm 264 and the output of the weighing device 250 are connected to each other via a control device, not shown. The weighing device 250 measures the weight of the material deposited on the weighing device 250, which may vary even with ideal volumetric dosing due to sedimentation. As a result of this variation, the weighing device 250 measures changing masses of the Gutstranges deposited on the conveyor belt 252. This weight signal is evaluated by the controller and causes a change in the rotational speed of the screw 264 by acting on the associated in the screw 264 drive motor with the aim that a predetermined length of the deposited on the feed side 225 of the metering plate 200 Massestranges has a constant mass weight. In particular, it is of interest that the strand of material which is discharged into a funnel opening 230 in each case. The aim is to achieve a substantially constant weight-filling of the individual bags 30 despite sedimentation and different density of the bulk material.

FIG. 5 shows a representation substantially corresponding to the FIG. 3 for another circumferential portion of the anvil wheel 110 and illustrates a designated by reference numeral 300 welding device for closing the bag. This welding device has a fixed anvil 310, which is arranged between the bag 30 to be closed of the projections 112 enveloping cylindrical surface. On the opposite side of the stationary anvil 310 is a rotating sonotrode 320, which can be driven at the speed with which the bags 30 are guided past the welding device 300.

The FIG. 6 lets recognize the components of the embodiment described above. In addition, a gripper arrangement indicated by reference numeral 400 is shown, which is provided substantially on the underside of the anvil wheel 110 facing away from the dosing plate 200. This gripper assembly 400 has a plurality of gripping means 410 substantially rotating on a circular path, the essential components of which are in the FIGS. 7A to G and 8th can be seen. Thereafter, each gripping device 410 is supported by a gripper base indicated by reference numeral 412 which supports pivotally driven gripper arm pairs 414. At the free ends of two gripper arms 416, a folding arm 418 is arranged, the free end of which projects beyond the gripper base 412 and is provided with hammer-head-like folding projections 420. The folding arms 418 are curved in the front area like a prong to each other and close in the in FIG. 7 characterized position flat jaws 422 of the gripping device 410, which are pivotally mounted about an axis parallel to the fold 8 extending axis, ie about an axis which extends substantially in the horizontal, said pivot axis of the jaws 422 by a Fork carrier 426 is pivotable about an axis perpendicular thereto, which extends vertically. The fork carriage 426 is mounted to pivot and driven on the gripper base 412. The pivoting movement of the fork carrier 426 and the pivotal movement of the clamping jaws 422 can be positively controlled by scenes, which, depending on the angle of rotation of the gripping device 410 with respect to the center of rotation M ( FIG. 8 ) cause the necessary movements of the gripping device 410.

FIG. 8 shows a plan view of the bottom of the previously discussed embodiment, wherein the gripper assembly 400 is disposed upstream of the anvil 110. The anvil wheel 110 and the gripper assembly 400 rotate about the common center M. In this case, the gripper assembly 400 for each gripper device 410 additionally has a longitudinal guide over which each individual gripping device 410 is translationally movable in the radial direction. In FIG. 8 Gripper carrier 426 are schematically drawn, which are mounted displaceably in the radial direction on spokes 428 of the gripper assembly 400. Recognizable are different radial positions of the gripper carrier 426 relative to the center of rotation M.

The functionality of the individual gripping devices 410 will now be described with reference to positions shown in FIG FIG. 8 are marked with reference numerals A to G. In these positions, the actuating elements of the gripping device 410 have the respective positions according to the FIGS. 7A to 7G ,

In the FIG. 7A shown position, ie at a twist angle of 0 ° of the fork carrier 424 relative to the gripper base 412 and open jaws 422, the gripper carrier 426 is in an inner radial position, the in FIG. 8 is denoted by reference A. The deflected path 10 is thereby moved between the open clamping jaws 422, which close at position B by pivoting and clamp the fold 8 of the track 10 closed on the underside. The corresponding position of the jaws 422 is in FIG. 7B shown. In this case, the fork carriage 424 continues to have a pivot angle of 0 °, ie is in the starting position.

With this orientation, the web 10 passes through the bag sealer 100.

Thereafter, the fork carriage 424 is pivoted, during which the filling tubes 210 dive into the bags 30 (see. FIG. 6 ). The folding arms 418 remain in their in the FIGS. 7A and 7B marked starting position. In position D (cf. FIG. 8 ), the bag 30 has been pivoted by 90 °, so that the initially tangentially relative to the anvil 110 extending fold 8 is now radially aligned with the center M (see. Figure 7D ). The pivoting movement of the fork carriage 424 has thus come to an end. It begins the pivoting movement of Greiferarmpaare 414, ie the folding arms 418 (see. Figure 7E ). The folding arms 418 rest against the transverse welds 126 of the bags 30 and slide in the direction of the open end of the bag 30. The bag 30 is folded over. The initially opposite longitudinal sides of the web 10 are kinked in the middle (kink K -. FIGS. 7D to F ). To this kink K pivoting of the upper edge portions of the bag 30 is carried out until the Querabschweißung 126 centrally containing longitudinal sections opposite to the bag mouth (see. FIG. 7F ).

As the pivoting movement of the folding arms 418 progresses, these open longitudinal sections of the bag mouth are pressed against one another, so that a contact region 430 shaped approximately with the thickness of the fold 8 is formed (cf. FIG. 7G ). Thereafter, the pivoting movement of the folding arms 418 from its initial position (see. figure 7A, B ) into its final position (cf. FIG. 7G ) completed. The contact area 430 is now guided and welded to the fixed anvil 310 and the rotating sonotrode 320.

FIG. 9 shows in the left position of this top-side closing of the bag 30 and thus the production of the tea bag 40. In the subsequent position H, the folding arms 418 have moved down again. In the position marked I, the folding arms 418 have already been pivoted back to their starting position. At position J according to FIG. 9 The finished tea bags 40 are discharged in the radial direction, for example, by an air pressure shock, which is ejected by a arranged between the tea bag 40 and the anvil 110 air nozzle. In position K, the jaws 422 pivoted back to the starting position and opened.

This results in the following procedure:

In a continuous movement, the web 10 closed on the underside is initially applied tangentially to the anvil wheel 110. At the bag sealer 110, individual chambers are created by transverse welds 126. This results in different, already separated by the dividing seam 124 bags 30, which are not yet isolated and which appear as a continuum. By pivoting the fork carriage 424, the bags 30 are now isolated. The separation takes place by a superposition of a pivoting movement of the fork carriage 424 with simultaneous radial movement of the gripper carrier 426 along the spokes 428 to the outside. As a result, a certain radial distance between the bags 30 and the envelope surface is created around the projections 112, so that later the bags open on one side can be guided past the anvil 310 located radially in front of the anvil wheel 110. As part of a continuous rotational movement about the center M, the bags 30 are pivoted by 90 °, so that the fold 8 now occupies a radial orientation. The bags 30 are folded with their protruding from the fold 8 wall sections, which are initially aligned parallel to the fold 8, folded, so that these parallel wall sections are provided with the central kink K. Thereafter, the opposite, provided with the Querabschweißung 126 side walls of the bag 30 are applied by further pivoting of the folding arms 418 under bias against each other and finally closed in the contact area 430 to form a further weld 432 by the welding device 300. This further weld 132 extends at right angles to the fold 8, so that a tetrahedron bag formed with four side surfaces, a lower-side fold and three welds 432, 126 arranged at right angles to each other.

While maintaining the clamping by the jaws 422, the folding arms 418 are then pivoted back to their original position. After this station H, the fork carriage 424 is pivoted back to its original position, in which the pivot axis of the jaws 422 extends substantially tangentially in the center M. In the angular segment between position 7 C and 7 D as shown in FIG FIG. 8 pushes the sliding member 268 on the task side 225 the mass strand of the stored there good in the hopper openings 230 so that the good is dropped on the filling tubes 210 in the bags 30.

LIST OF REFERENCE NUMBERS

2

flat track

4

supply roll

6

fold railway

8th

wrinkle

10

closed track on the underside

12

idler pulley

14

rotating welding device

16

welding roll

17

welding jaw

18

welding roll

19

welding jaw

20

jet

22

separator

24

gripper

26

tape

28

holding web

30

bag

32

filling pipe

34

trajectory

36

scenery

38

welder

40

Teabag

100

Tütenabschweißeinrichtung

110

anvil

112

head Start

114

foot

116

sonotrode

118

sonotrode

120

Rotary axis of the anvil wheel

124

separating seam

126

Querabschweißung

200

metering plate

210

filling pipe

220

loading side

225

task page

230

funnel opening

240

Rotary axis of the dosing plate

250

weighing

252

conveyor belt

260

metering

262

outlet pipe

264

slug

266

metering funnel

268

sliding element

300

welding equipment

310

anvil

320

sonotrode

400

hook assembly

410

gripper

412

gripper base

414

Greiferarmpaar

416

gripper

418

folding arm

420

Faltarmvorsprung

422

jaw

424

Gabelträger

426

gripper carrier

428

spoke

430

plant area

432

another weld

M

Center / pivot point

K

kink

Claims (12)

1. Method of producing bags (40), in particular infusion bags, whereby a flat web (2) is folded lengthways to form a web (10) closed at the bottom end by means of a fold (8), chambers disposed one after the other in the longitudinal direction of the web (10) are sectioned off, and
   pouches (30) open at one side are separated from the web (10) by means of a cut welding seam (124) disposed between adjacent chambers, after forming the cut welding seam (124) the chambers are filled with product and bags (40) sealed by a welding seam (432) lying on the side opposite the fold (8) and separated by cutting the web (10) are conveyed away,
   characterised in that
   the welding seam (432) is disposed extending essentially at a right angle to the fold (8) and the pouches (30) open on one side are pivoted prior to sealing so that the fold (8) is oriented essentially at a right angle to the forward feed direction of the pouches (30).
2. Method as claimed in claim 1, characterised in that the material forming the bags (40) is moved continuously at least before forming the cut welding seam (124) until sealing on the side lying opposite the fold (8).
3. Method as claimed in claim 1 or 2, characterised in that the material forming the bags (40) is moved essentially about a pivot point (M).
4. Method as claimed in claim 2 or 3, characterised in that, before forming the cut welding seam (124) until sealing on the side lying opposite the fold, the material forming the bags (40) is gripped by a gripping device (410, 422) co-operating with an individual bag (40) and conveyed until the bag (40) is produced by sealing on the side lying opposite the fold (8).
5. Method as claimed in one of the preceding claims, characterised in that pouches (30) open at one end are separated.
6. Device for producing bags, in particular infusion bags, with
   a folding device for folding a flat web,
   a gripping arrangement (400) gripping the folded web (10) with a plurality of gripping devices (410) for clamping the fold (8) moved about a pivot point (M), a rotating metering plate (200) with an input side (225) for inputting the product and an oppositely lying filling side (210) from which project a plurality of filling tubes (210) which can be introduced into chambers formed by the web (10), the axis of rotation (240) of which is oriented at an angle to an axis of rotation (120) of the anvil wheel and/or the gripping arrangement (400);
   a welding unit (300) for sealing the bag (40) and
   a discharge device for discharging the bag (40),
   characterised in that
   the gripping devices (422) are configured so that they clamp the flat web (2) at the fold (8),
   a pouch welding unit (100) is provided, comprising a toothed anvil wheel (110) moved about the pivot point (M) and a sonotrode (116) co-operating with projections (112) of the anvil wheel (110) to form chambers and pouches (30) between the chambers separated by a cut welding seam (124),
   the gripping devices (422) are mounted so as to be respectively pivotable so that, prior to sealing, the pouches can be pivoted so that the fold (8) is oriented essentially at a right angle to the forward feed direction of the pouches (30) and
   the welding unit (300) is disposed so that it can seal the pouch (30) with a welding seam extending essentially at a right angle to the fold (8).
7. Device as claimed in claim 6, characterised in that the sonotrode (116) is stationary and oriented at an angle to the anvil projections (112).
8. Device for producing bags as claimed in claim 6 or 7, characterised in that the welding unit (300) for sealing the bags (40) has a stationary anvil (310), which is disposed between the anvil wheel (110) and a sonotrode (320).
9. Device as claimed in claim 8, characterised in that the sonotrode is a rotating sonotrode (320).
10. Device as claimed in one of claims 6 to 9, characterised in that the gripping device (422) is mounted on a gripper base (412), which provides a mount in a pivotable arrangement for at least two folding arms (418) acting on the open end of the pouch.
11. Device as claimed in one of claims 6 to 10, characterised in that the gripping devices (422) are mounted so as to be displaceable in translation in the radial direction of the gripper arrangement (400).
12. Device as claimed in one of claims 6 to 11, characterised in that a metering unit (260) and a weighing unit (250) which detects a mass flow dispensed by the metering unit (260) co-operate with the input side (225) of the metering plate (200), and a controller is provided which compares an actual value of the mass flow detected by the weighing unit (250) with a desired value and controls the mass flow dispensed by the metering unit (260) on the basis of this comparison.

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