DE202007003450U1 - Induction heating head for sealing containers comprises spaced induction coils with flexible connections to allow the container to pass between them - Google Patents

Abstract

sealer (1) with at least one induction coil (6) of one at least partially flexible conductor (6c, 6d, 6d ', 6d' 'for inductive sealing of by the sealing device (1) moving containers (2) by merging a container opening with a sealing film (7), characterized in that the induction coil (6) two coil halves (6a, 6b) arranged at a distance (d) from each other 6b), in which the conductor (6c) each substantially parallel to a direction of movement (B) of the container (2) extends and between which the containers (2) are movable through, wherein the coil halves (6a, 6b) over at least a flexible conductor loop (6d, 6d ', 6d' ') extending vertically to the direction of movement (B) of the container (2) extends to the induction coil (6) are connected.

Description

The The present invention relates to a sealing device according to the preamble of claim 1 with at least one induction coil an at least partially flexible conductor for inductive sealing of containers moved by the sealing device Melting of a container opening with a sealing foil.

devices for inductive sealing basically include a high frequency generator (HF generator) and an induction coil (or short: coil), the is arranged in a sealing head. The coil can be flat or tunnel-shaped trained and also from a ferrite cladding be surrounded by the electromagnetic field in the direction of application concentrated. The coil is usually in a series resonant circuit integrated, which is driven near the resonance frequency to Current increases in to produce the coil.

Of the Sealing head is usually over a conveyor arranged with the help of which to be sealed container or Be transported under the coil package. The containers are through closed a screw-on or latchable lid, the a metal foil and an adjacently arranged plastic sealing foil contains. With Help the induction coil eddy currents are generated in the metal foil, which heat the metal foil. Through the contact between metal and sealing film is also the Heated sealing film and thereby fused with the container opening. tunnel-shaped Induction coils face flat coils have the advantage that even containers with a large distance be sealed between the metal foil and the top of the lid can, because the coil acts from the side on the metal foil.

From the EP 0 842 854 B1 ( DE 697 04 191 T2 ) is known to make a sealing head with tunnel-shaped induction coil geometrically so that container openings of different widths can be sealed. For this purpose, a step-shaped opening is formed in the sealing head, which receives in operation differently wide container lid in their different sized opening portions. A disadvantage of the in the EP 0 842 854 B1 described device is, however, that it is optimally adapted only for container lid vorbestimmer size and that the action of the electromagnetic field of the induction coil on the container is mainly from above, so that containers with high covers, ie a large distance between the top lid and inner metal foil only can be sealed badly.

In contrast, is It is the object of the present invention to provide a device of initially mentioned type for inductive sealing of container openings specify with the container variable lid shape, height and size easy and can be sealed efficiently.

The Task is solved by a sealing device having the features of the patent claim 1. Advantageous developments of the sealing device according to the invention are in the subclaims the wording of which is hereby incorporated by reference the description is made in order to avoid unnecessary text repetitions avoid.

According to the invention is a Sealing device comprising at least one induction coil an at least partially flexible conductor for inductive sealing of containers moved by the sealing device Melting of a container opening with a sealing film, characterized in that the induction coil has two coil halves arranged at a distance from one another, in which the conductor in each case substantially parallel to a direction of movement the container runs and between those the containers are hindurchbewegbar, wherein the coil halves via at least one flexible Conductor loop, which extends perpendicular to the direction of movement of the container to the induction coil are connected. So the leader is at least flexibly formed in the region of the conductor loop.

The two parallel halves The coil winding thus form a tunnel through which one to sealing container emotional. The influence of the electromagnetic field of the induction coil on the container Therefore, it is done from the side, so that containers with high lids well can be sealed. Furthermore the electromagnetic field of the induction coil acts on it Way targeted to the edge of the metal lid located in the container lid one where the heat development for the sealing process required becomes.

According to a particular embodiment of the present invention, there is provided an induction coil sealing apparatus consisting entirely of flexible stranded wire, wherein the stranded wire in multiple windings extends substantially in two parallel coil halves parallel to the direction of movement of the containers to be sealed, and also a number of conductor loops perpendicular to this direction of movement and in particular also forms perpendicular to the plane of the container opening. The design of the induction coil of a flexible, multi-core conductor in the form of stranded wire makes a complex water cooling of the coil unnecessary. The cooling of the coil can in a simple and cost-effective manner with Hil be made of air.

The Conductor loops, the stranded wire of the induction coil perpendicular to the direction of movement of the container to be sealed, allow a Parallel displacement of the coil position parallel in a normal position or winding halves against each other, so that between the parallel winding halves stepless a variable distance can be set. In this way, containers with different opening widths to be sealed. The conductor loops extend so far out of the Level of the container opening out, that they are no obstacle to the movement of the containers represent.

In a preferred embodiment can the coil halves Furthermore be positioned at an angle to each other to the impact of the electromagnetic coil field to influence the container. The between enclosed the coil halves imaginary angle can be in a plane of container movement or the container opening and / or lie in a plane perpendicular thereto.

Generally can the coil halves are therefore arranged at a finite angle to each other, wherein the angle with respect to the direction of movement of the container and / or with respect to a direction perpendicular to this direction. The term "finite angle" refers to the present case an angular measure unequal Zero degrees (0 °).

Preferably is the induction coil in an at least perpendicular to the direction of movement of the container slidable sealing head arranged so that container with sealed variable lid height can be. In other words: in development of the sealing device according to the invention the induction coil is movable perpendicular to the direction of movement of the container arranged.

Especially preferred is the induction coil with at least one capacitor or a capacity in a serial resonant circuit interconnected to in the coil Current overshoots too produce. The entire resonant circuit is arranged in the sealing head, the over flexible connection means in the form of connecting cables is connectable to the high frequency generator. This allows a easy interchangeability of at least the coil, the capacity and appropriate Connection means for connecting to the RF generator comprehensive seal head in an existing sealing device, in particular for retrofitting purposes.

In In a further development of the invention, the induction coil is in several Sub-coils divided, between each of which at least one capacitor or a capacity is arranged. In this way, the tension in the individual Part coils are lowered to avoid flashovers.

to Concentration of the electromagnetic field of the induction coil Is it possible, the parallel winding halves the coil with a cladding from a magnetically good and electrically poorly conductive material, especially ferrite, to surround.

For a simple Application of the sealing head is preferably the (parallel) displacement the coil halves the induction coil in synchronism with an adjustment of a guide unit for the sealing container. These are the mechanical adjustment of the coil and the adjustment operatively coupled to the container guide or preferably identical, i. they are in the form of a common Adjustment formed.

Further Advantages and characteristics of the present invention will be apparent from the following description of exemplary embodiments with reference to FIG Drawing. From the individual embodiments to be taken Features can be individually or in combination in embodiments of the present invention be realized. It shows:

1 a basic schematic representation of a sealing device according to the invention for the inductive sealing of containers;

2 a first embodiment of the induction coil in the sealing head of a sealing device according to the invention in cross section;

3 a plan view of an embodiment of the induction coil according to 2 ;

4 a plan view of a further embodiment of the induction coil according to 2 ;

5 a further embodiment of the induction coil in a sealing device according to the invention with an adjustment device for the induction coil in cross section;

6 a plan view of the arrangement according to 5 in which two adjusting devices are arranged one behind the other;

7 a further embodiment of the induction coil of the sealing device according to the invention; and

8th an arrangement of induction coil, Capacity, adjusting device and connecting means on an exchangeable frame part for a sealing device according to the invention.

1 shows a basic schematic representation of a sealing device according to the invention 1 for inductive sealing of containers or containers 2 , The sealing device 1 has a high frequency generator (HF generator) 3 in conjunction with a resonant circuit 4 on. The resonant circuit 4 includes a capacity 5 used to achieve an overcurrent with an induction coil (inductance) 6 is connected in series. At least the induction coil 6 (see. 8th ) is in a movable sealing head 1a the sealing device 1 arranged. The sealing head 1a is movable as a whole at least in the direction of the double arrow A to the sealing device 1 to different height dimensions h of the container to be sealed 2 adapt. Will the entire resonant circuit 4 arranged in the sealing head, which is connectable via connection means, in particular in the form of flexible connecting lines (cable), with the high-frequency generator, this allows a simple interchangeability of the sealing head in an existing sealing device.

In the current-carrying state generates the induction coil 6 an (electro) magnetic field H, in the region of which a container to be sealed 2 with a container opening or a sealing foil present on the container opening 7 is arranged. The container 2 is typically by means of a conveyor 8th such as a conveyor belt, optionally in conjunction with a guide device 9 with a direction of movement B through the area of the magnetic field H, ie through the sealing device 1 emotional. This will make the sealing film 7 heats and melts with the material of the container 2 so that it is sealed. The induction coil 6 is according to the invention in deviation from the purely schematic representation in 1 designed as a tunnel-like induction coil or tunnel inductor, which will be discussed in more detail below.

2 shows a first embodiment of the induction coil 6 in the sealing head 1a ( 1 ) of a sealing device according to the invention 1 , The induction coil 6 has two coil halves, namely a first coil half 6a and a second coil half 6b on. The induction coil 6 is mehrwindig using a multi-core flexible conductor in the form of a stranded wire 6c formed, whose sections in the first and second coil halves 6a . 6b each substantially parallel to each other and substantially parallel to the direction of movement B of the container 2 run and thus in 2 each shown in cross section. The term "substantially" used is intended to express that within the scope of the present invention also embodiments of the induction coil 6 are possible, in which the first and second coil halves 6a . 6b to each other and / or with respect to the direction of movement B in a finite angle, that is an angle not equal to 0 ° and preferably between 0 ° and 45 ° are arranged, which will be discussed in more detail below (see. 6 and 7 ).

The two coil halves 6a . 6b are to create the induction coil 6 through further, in 2 schematically illustrated in dashed lines Litzendrahtabschnitte connected together a conductor loop 6d form perpendicular to the direction of movement B and perpendicular to the opening of the container 2 extending level. In this way is a tunnel-like induction coil 6 (Tunnel inductor) formed. Although in the present case only a single conductor loop 6d can be shown, in the direction of a longitudinal extent of the coil halves 6a . 6b also a plurality of conductor loops 6d be provided, in particular two, that is, a conductor loop at each end of the two coil halves 6a . 6b , Due to the use of a flexible conductor 6c as well as the training of conductor loops 6d let the two coil halves 6a . 6b initially in a simple manner parallel in the direction of the double arrow D, so that there is a distance d between the two coil halves 6a . 6b can be adjusted continuously in order to be able to react flexibly to different container dimensions in this way. The conductor loop 6d is further designed and dimensioned so that container 2 with a high lid, ie a large distance between the upper edge of the lid and the sealing foil 7 can pass through the formed induction coil tunnel unhindered.

According to the embodiment of the 2 are the two coil halves 6a . 6b on their respective from the container 2 opposite side with a Teilumhüllung 6e respectively 6f surrounded, which is formed of a material having a good magnetic conductivity and a poor electrical conductivity. Preferably, but without limitation, this material is a ferritic material (ferrite). In this way, this can be done by the induction coil 6 generated field on the area between the two coil halves 6a . 6b be concentrated.

3 shows a schematic plan view of the induction coil 6 according to 2 , here in an embodiment with two conductor loops 6d . 6d ' through which a single induction coil 6 is formed. This assigns 6g Connections for connecting the induction coil 6 with the others in 1 shown components of the sealing device 1 on, especially the capacity 5 and the RF generator 3 ,

As in 4 It is also possible to use the induction coil 6 so from a number of sub-coils 6 ' . 6 '' build up that correspondingly more conductor loops 6d - 6d '' and connections 6g . 6g ' result. In this way, more capacity can be 5 ' between the individual coil sections 6 ' . 6 '' Switch, so that the voltage in the individual sub-coils 6 ' . 6 '' can be lowered to avoid flashovers. Alternatively it is possible to use the partial coils 6 ' . 6 '' be executed so that only two conductor loops arise.

5 shows schematically an adjusting device 10 for the induction coil 6 , ie for the arrangement of the two coil halves 6a . 6b , The adjusting device 10 is in the illustrated embodiment with an adjustment for the container guide device 9 identical. It has a cross-sectionally U-shaped structural element or housing part 10a on, over its entire cross section of a double threaded rod 10b is interspersed. The double threaded rod 10b has a first threaded portion 10c and a second threaded portion 10d on, wherein the thread in the second threaded portion 10d to the thread in the first threaded portion 10c is in opposite directions. A middle section 10e the double threaded rod 10b is thread-free. At one end of the threaded rod 10b is a control 10f arranged in the form of a knob; the other end of the double threaded rod 10b is by means of an abutment part 10g on the structural element 10a held. The two coil halves 6a . 6b each have one in a direction perpendicular to the container movement direction B and in the extension direction of the conductor loop 6d extending attachment part 6h . 6i on which at its free end a passage 6y . 6k with internal thread for receiving the double threaded rod 10b has. At their respective inner side, ie at the side to be sealed containers (not shown here) side facing the attachment parts 6h . 6i already referring to 1 mentioned container guide device 9 on.

By turning the knob 10f is therefore about a movement of the double threaded rod 10b a parallel displacement of the two coil halves 6a . 6b in the direction of the double arrow D, causing a uniform change in the distance d between the coil halves 6a . 6b over its entire longitudinal extent comes. Due to the (mechanical, effective) coupling between the induction coil 6 or the two coil halves 6a . 6b on the one hand and the attachment parts on the other 6h . 6i On the other hand, at the same time a corresponding adjustment of the container guide device 9 reached.

The settings are not limited to the adjustment described above by hand. In particular, the rotational movement described the double threaded rod 10b also be effected by suitably controlled electric drive means (not shown) or the like. Likewise, a regulation of the drive means for adaptation to an alternating container width is possible, for which purpose the sealing device optionally has corresponding suitable sensors (not shown) for the container width.

In particular, when at a container in the direction of movement B front or rear end of the coil halves 6a . 6b each an adjusting device 10 according to 5 is provided, the two coil halves can be 6a . 6b even at a finite angle not equal to 0 ° relative to the container movement direction B order. This is in the following 6 shown schematically:

6 shows a plan view of the arrangement according to 5 in which, in the direction of the container movement B, two adjusting devices 10 . 10 ' (see 5 ) in a common structural element 10a arranged one behind the other. The individual elements of the 6 arise in particular from the 2 to 5 , so this is not discussed here. As shown, can be achieved by different actuation of the adjustment 10 . 10 ' an angularly symmetrical arrangement of the two coil halves 6a . 6b with respect to the container movement direction B, wherein the angle between the direction of movement B and the respective coil half longitudinal axis is designated by α. In this way, in particular, an intensity of the induction effect which increases in the direction of the container movement B can be achieved. The reverse arrangement (increasing distance d in the direction of the container movement B) is possible.

In the course of this embodiment, it may be necessary, the connection between the coil halves 6a . 6b and the respective parts of the approach 6h . 6i flexible, in particular rotatable design.

7 shows a further embodiment of the induction coil 6 the sealing device according to the invention, wherein the type of representation in principle those in 2 respectively 5 equivalent. Due to the flexible design of the conductor in the area of the conductor loop (s) 6d is according to the invention also a quasi arbitrary relative arrangement of the two coil halves 6a . 6b in a plane perpendicular to the container movement direction B feasible. In the present case, the two coil halves 6a . 6b in each case by an angle β with respect to the Ver tical V tilted inwards. The reverse arrangement (tilting outward) is possible. In the course of the embodiment according to 7 In particular, an embodiment of the adjustment 10 with separate threaded rods (not shown) for separately moving / tilting the individual coil halves 6a . 6b or a completely different embodiment of the adjustment may be required, which is not the subject of the present application. Also an orientation of the coil halves 6a . 6b parallel to the vertical V, but with a certain height offset to each other coil half can be realized in this way.

As those skilled in the art will appreciate, the angled arrangements are as per 6 and 7 basically not limited to symmetrical arrangements.

As 8th schematically shows schematically, the entire arrangement of induction coil 6 and adjusting device 10 on a frame or holding part 11 arranged, which is also the capacity or capacities 5 . 5 ' and a connection device 12 for connecting the induction coil 6 or from the induction coil 6 and capacities 5 . 5 ' formed resonant circuit 4 (see 1 ) with the HF generator 3 includes. Referring again to the 1 Thus, the above elements form the sealing head 1a the sealing device 1 , In this case, come to connect the connection device 12 flexible connection means 13 such as cables or the like, for use around the sealing head 1a in an existing sealing device 1 to exchange in a simple way.

Claims (14)

Sealing device ( 1 ) with at least one induction coil ( 6 ) from an at least partially flexible conductor ( 6c . 6d . 6d ' . 6d '' for inductive sealing of by the sealing device ( 1 ) moving containers ( 2 ) by fusing a container opening with a sealing film ( 7 ), characterized in that the induction coil ( 6 ) two mutually spaced coils (halves) (d) ( 6a . 6b ), in which the conductor ( 6c ) each substantially parallel to a direction of movement (B) of the container ( 2 ) and between which the containers ( 2 ) are movable through, wherein the coil halves ( 6a . 6b ) via at least one flexible conductor loop ( 6d . 6d ' . 6d '' ) perpendicular to the direction of movement (B) of the containers ( 2 ), to the induction coil ( 6 ) are connected. Sealing device ( 1 ) according to the preceding claim, characterized in that the at least one flexible conductor loop ( 6d . 6d ' . 6d '' ) extends perpendicular to the plane of the container opening. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the entire conductor ( 6c . 6d . 6d ' . 6d '' ) is flexibly formed from stranded wire. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the induction coil ( 6 ) is formed mehrwindig, wherein conductor portions of the conductor ( 6c ) in the coil halves ( 6a . 6b ) are arranged parallel to each other. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the coil halves ( 6a . 6b ) are arranged for adjusting the distance (d) of the coil halves to each other movable. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the coil halves ( 6a . 6b ) are arranged for setting a finite angle (α, β) to one another such that the angle with respect to the direction of movement (B) of the container ( 2 ) and / or with respect to a direction perpendicular thereto. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the induction coil ( 6 ) perpendicular to the direction of movement (B) of the containers ( 2 ) is movably arranged. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the induction coil ( 6 ) with at least one capacity ( 5 . 5 ' ) in terms of circuitry to a resonant circuit ( 4 ), in particular connected in series. Sealing device ( 1 ) according to the preceding claim, characterized in that the resonant circuit ( 4 ) Connection means ( 12 ) for a flexible connection to a high-frequency generator ( 3 ) having. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the induction coil ( 6 ) is subdivided into a plurality of sub-coils and that in each case a capacity ( 5 . 5 ' ) is switched. Sealing device ( 1 ) according to one of the preceding claims, characterized in that the induction coil ( 6 ), in particular in each case the coil halves ( 6a . 6b ), at least partially with an envelope ( 6e . 6f ) from a material give, which has a good magnetic conductivity and a poor electrical conductivity. Sealing device ( 1 ) according to one of the preceding claims, characterized by at least one adjusting device ( 10 . 10 ' ) for an arrangement of the coil halves ( 6a . 6b ). Sealing device ( 1 ) according to the preceding claim, characterized in that the adjusting device ( 10 . 10 ' ) for the arrangement of the coil halves ( 6a . 6b ) and at least one adjusting device for a guide device ( 9 ) for the containers ( 2 ) operatively coupled and / or in the form of a common adjusting device ( 10 . 10 ' ) are formed. Sealing head ( 1a ) for a sealing device ( 1 ) according to one of the preceding claims, characterized in that the sealing head ( 1a ) at least the induction coil ( 6 ) and connection means ( 12 ) for a connection of the induction coil ( 6 ) with a high-frequency generator ( 3 ) and, if necessary, the capacity ( 5 . 5 ' ) and / or the adjusting device ( 10 . 10 ' ) for the arrangement of the coil halves ( 6a . 6b ) and / or the adjusting device ( 10 . 10 ' ) for the management body ( 9 ) for the containers ( 2 ).