A PRESSURE JAW ASSEMBLY AND A SEALING JAW ARRANGEMENT

Abstract

A pressure jaw assembly (1) for a sealing jaw arrangement of a filling machine. The pressure jaw assembly (1) comprises a pressure jaw frame (10), a pressure element (20) arranged to be moved relative the pressure jaw frame (10), a compressing means (40) arranged at least partly between the pressure jaw frame (10) and the pressure element (20). The compressing means (40) is arranged to influence the relative movement between the pressure element (20) and the pressure jaw frame (10). The pressure jaw assembly (1) further comprises a guide (50, 52) for guiding the pressure element (20). The guide (50, 52) is connected to the pressure jaw frame (10), and the guide (50, 52) is arranged externally of the pressure element (20).

Claims

1. A pressure jaw assembly for a sealing jaw arrangement of a filling machine, said pressure jaw assembly comprising: a pressure jaw frame, a pressure element arranged to be moved relative said pressure jaw frame, a compressing means arranged at least partly between said pressure jaw frame and said pressure element, said compressing means being arranged to influence the relative movement between said pressure element and said pressure jaw frame, a guide for guiding said pressure element, wherein said guide is connected to said pressure jaw frame, and wherein said guide is arranged externally of said pressure element.

2. The pressure jaw assembly according to claim 1, wherein said pressure element comprises at least a first guiding surface, and said guide comprises at least a second guiding surface whereby said pressure element is guidable along said guide by said first and said second guiding surfaces.

3. The pressure jaw assembly according to claim 1, wherein said pressure element is coupled to said guide by a male-female arrangement in order for said pressure element to be guidable along said guide.

4. The pressure jaw assembly according to claim 3, wherein said guide comprises at least one groove, and said pressure element comprises at least one elongated protrusion arranged to be guided inside said groove.

5. The pressure jaw assembly according to claim 1, wherein said guide is a separate part compared to the pressure jaw frame, and wherein said guide is made of a different material compared to said pressure jaw frame.

6. The pressure jaw assembly according to claim 1, wherein said pressure jaw frame comprises a first end portion and a second end portion arranged distant from said first end portion, and wherein said guide is a first guide and said pressure jaw assembly further comprises a second guide, said first guide being connected to said first end portion, and said second guide being connected to said second end portion.

7. The pressure jaw assembly according to claim 1, wherein said compressing means is a compression spring.

8. The pressure jaw assembly according to claim 1, further comprising connecting means arranged to connect said pressure element and said pressure jaw frame, and wherein said compressing means is arranged between said connecting means and said pressure element and/or said pressure jaw frame.

9. The pressure jaw assembly according to claim 1, further comprising at least two elongated cutting rails arranged in connection with said pressure element, said elongated cutting rails being arranged an opposite side of the pressure element compared to the compressing means.

10. A sealing jaw arrangement for a filling machine, said sealing jaw arrangement comprising a pressure jaw assembly according to claim 1, and a heating jaw.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above objects, as well as additional objects, features and advantages of the present invention, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, when taken in conjunction with the accompanying drawings, wherein:

[0048] FIG. 1 is a cross-sectional view of a pressure jaw assembly in accordance with at least one embodiment of the invention;

[0049] FIG. 2 is a perspective view of a pressure jaw assembly in accordance with at least one embodiment of the invention;

[0050] FIG. 3 is a perspective view of a heating jaw assembly, which together with a pressure jaw assembly form a sealing jaw arrangement, in accordance with at least one embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0051] FIG. 1 shows a pressure jaw assembly 1 in accordance with one embodiment of the present invention. The pressure jaw assembly 1 comprises a pressure jaw frame 10 and a pressure element 20 connected to each other by connecting means 30, in FIG. 1 illustrated as two bolts 30A, 30B. The pressure jaw assembly 1 further comprises a compressing means 40 arranged at least partly between the pressure jaw frame 10 and the pressure element 20. In FIG. 1, the compressing means 40 is embodied as two compression springs 40A, 40B, each surrounding one of the bolts 30A, 30B. Even though two bolts 30A, 30B and two compressing springs 40A, 40B are present in FIG. 1, the pressure jaw assembly 1 may comprise only one connecting means (e.g. only one bolt) and one compressing means (e.g. only one compressing spring). The connecting means 30 is connecting the pressure jaw frame 10 to the pressure element 20 such that a gap G is provided between the pressure jaw frame 10 and the pressure element 20. The gap G provides a space into which the pressure element 20 can be moved when being subject to an external force in a direction towards the pressure jaw frame 10.

[0052] The pressure jaw assembly 1 further comprises a guide 50, 52, connected to the pressure jaw frame 10. The guide 50, 52 is arranged externally of the pressure element 20 and is arranged to guide the pressure element 20 as it is moved relative the pressure jaw frame 10 (the use of the pressure jaw assembly 1 is further explained below with reference to FIGS. 2 and 3). In FIG. 1, the pressure jaw assembly comprises a first guide 50 and a second guide 52 arranged externally on opposite sides of the pressure element 20.

[0053] The first and the second guides 50, 52 will now be explained in more detail. Each of the guides 50, 52 are connected to a respective end portion of the pressure jaw frame 10. In other words, the pressure jaw frame comprises a first end portion 12 connected/attached to the first guide 50, and a second end portion 14 connected/attached to the second guide 52. As illustrated in FIG. 1, the first and the second end portions 12, 14 are arranged distant from each other, on opposite sides of a center axis C extending in the axial direction through the pressure jaw assembly 1. Hereby, the pressure element 20 is at least partly arranged between the first and the second guides 50, 52 whereby a movement of the pressure element 20 in a direction perpendicular to the center axis C is restricted by the first and the second guides 50, 52. In other words, the guides 50, 52 are arranged to limit the pressure element 20 with regards to movement in the direction perpendicular to the axial direction.

[0054] Furthermore, as the guides extend in a direction parallel to the axial direction, guidance of the pressure element 20 in the direction along the axial direction is provided.

[0055] Each of the first and second guides 50, 52 may be arranged as a separate part compared to the pressure jaw frame 10, e.g. if the guides 50, 52 are to be made out of a different material compared to the pressure jaw frame 10. However, each of the first and second guides 50, 52 may according to one example embodiment be made in one piece with the pressure jaw frame 10. In both cases, the guides 50, 52 may be seen as lateral elongations 50, 52 of the pressure jaw frame 10.

[0056] Each of the guides 50, 52 in FIG. 1 comprises a first guiding surface 51, 53 arranged to be in contact with a respective second guiding surface 22, 24 of the pressure element 20. In other words, the first guide 50 comprises a first guiding surface 51 arranged to be in contact with a second guiding surface 22, arranged at a first end portion 23 of the pressure element, and the second guide 52 comprises a first guiding surface 53 arranged to be in contact with a second guiding surface 24, arranged at a second end portion 25 of the pressure element 20. The first and second guiding surfaces 51, 53, 22, 24 have a main extension in a direction parallel to the center axis C, and thereby facilitate guiding of the pressure element 20 during its relative movement compared to the pressure jaw frame 10 along the axial direction. The guides 50, 52 may be coupled to the respective end portions 23, 25 of the pressure element 20 by a male-female arrangement (shown in FIG. 2).

[0057] In FIG. 2, a similar pressure jaw assembly 1 as the pressure jaw assembly 1 of FIG. 1 is shown. The pressure jaw assembly 1 in FIG. 2 comprises the same or similar features as the pressure jaw assembly 1 in FIG. 1, why the same reference numerals are used for corresponding features, and are not explained again with reference to FIG. 2. However, the pressure jaw assembly 1 in FIG. 2 is more detailed compared to the pressure jaw assembly 1 in FIG. 1, and the main differences to the pressure jaw assembly 1 of FIG. 1 is explained below.

[0058] In FIG. 2, the pressure jaw assembly further comprises two cutting rails 130, 132 attached to the pressure element 20. For example, the two cutting rails 130, 132 may be connected directly on the pressure element 20, on an opposite side to the compressing means (shown in FIG. 1 only). The cutting rails 130, 132 are arranged at a small distance from each other such that a slot 133 is formed between the cutting rails 130, 132. The slot 133 is formed to house a knife 110, and to allow the knife 110 to exit out of the slot 133 during a cutting operation. The knife is activated automatically by a reciprocating movement of the pressure jaw assembly 1, e.g. through a cam arrangement.

[0059] Even though the pressure jaw assembly 1 is shown comprising two cutting rails, 130, 132 it is possible to form a similar arrangement from a single piece, or to form it from different pieces, being attached in different ways.

[0060] As shown in FIG. 2, the pressure jaw frame 10 has a main extension in a direction being perpendicular to the center axis C. The main extension of the pressure jaw frame 10 extends from a first end portion 12 to a second end portion 14. As the pressure jaw assembly 1 in FIG. 1, the pressure jaw assembly 1 comprises a first guide 50 and a second guide 52. The first guide 50 extends from the first end portion 12 away from the pressure jaw frame 10 in a direction parallel to the center axis C, and the second guide 52 extends from the second end portion 14 away from the pressure jaw frame 10 in a direction parallel to the center axis C. Each of the first and the second guides 50, 52 is arranged with a groove 150, 152 arranged to hold and guide corresponding first and second elongated protrusions (shown in FIG. 1) of the pressure element 20, thus forming male-female arrangements.

[0061] Furthermore, in FIG. 2, a driving means 160 configured to allow the pressure jaw assembly 1 to be moved along a profile during use of the pressure jaw assembly 1 is shown. The pressure jaw assembly 1 is thus arranged to be moved along the profile during the sealing procedure of the tube of packaging material.

[0062] In FIG. 3, a heating jaw assembly 201 is shown. The heating jaw assembly 201 is arranged for interacting with the pressure jaw assembly 1, 1 during a sealing operation. The heating jaw assembly 201 typically comprises an inductor 210 for providing sufficient heat to the packaging material of the tube during the sealing procedure, and engaging means 205 arranged for engaging with the pressure jaw assembly 1, 1. The engaging means 205 is in FIG. 3 illustrated as first and second gripping claw 205A, 205B arranged to engage with the first and second guides 50, 52 as the heating jaw assembly 201 interacts with the pressure jaw assembly 1, 1.

[0063] As illustrated in FIG. 3, the heating jaw assembly 201 may also comprise a shallow groove 220 into which a knife of the pressure jaw assembly 1, 1 can enter during a cutting action. Thus, the inductor 210 may comprise an upper portion 212 and a lower portion 214 being separated by the shallow groove 220. The inductor 210 may further comprise an upper conductor arranged in said upper portion 212, and a lower conductor arranged in said lower portion 214 (i.e. the upper and lower conductor may be arranged on opposite sides of the shallow groove 220), for effectively heating the packaging material of the tube during the sealing procedure. The heat jaw assembly 201 may further comprise a cooling conduit (not shown) for cooling down the inductor 210.

[0064] Even though the heating jaw assembly 210 in FIG. 3 comprises an inductor for providing induction heat, but it is possible to have other forms of heat sealing, such as e.g. impulse heating, constant heating or ultrasonic sealing, as it is known to a person skilled in the art.

[0065] The function of the compressing jaw assembly will now be described with reference to FIGS. 2 and 3.

[0066] As the tube of packaging material is to be sealed, the pressure jaw assembly 1, 1 approaches the heating jaw assembly 201 by a suitable arrangement known in the art. For example, several pressure jaw assemblies may be arranged on a drive arrangement, and several heating jaw assemblies may be arranged on corresponding drive arrangement. The two drive arrangement may e.g. be arranged opposite to each other with the tube o packaging material arranged in between the two drive arrangement. As a pressure jaw assembly approaches and interacts with a heating jaw assembly, they together form a pair of sealing jaws for creating a transversal seal on the tube of packaging material.

[0067] As the tube of the packaging material is filled with liquid food, the tube of packaging material is transversally sealed such that separate packages portions with liquid food are formed. A transversal seal is performed by each pair of sealing jaws. The pressure jaw assembly 1, 1 and the heating jaw assembly 201 of a pair of sealing jaws are brought into contact with the tube of packaging material, which will flatten the tube. The heat generated by the heating jaw assembly 201 (e.g. by direct heating or induction heating) heats up the polymeric material on the inside of the tube, and the pressure arising from when the heating jaw assembly 201 is pressing the tube of the packaging material towards the pressure element 20 of the pressure jaw assembly 1, 1, make the inside surfaces of the tube to adhere to each other. In operation, a pair of sealing jaws forming a transversally seal is moved downward, feeding more packaging material to the tube-forming section. A new pair of sealing jaws is then brought into contact with the tube of the packaging material for creating a new transversally seal. In other words each pair of sealing jaws makes contact with the tube of packaging material at an almost constant position (position along Z), and the tube is then pulled down allowing for a new pair of sealing jaws to again make a transversal seal at the same position along Z as the previous pair of sealing jaws. This pulling action of the pair of sealing jaws on the tube is what feeds the web of packaging material through the machine. Sometimes, additional feeding rollers are provided further upstream in the filling machine, in order to reduce the tension in the web.

[0068] Two different pairs of sealing jaws may also create transversal seal on the tube orthogonally compared to each other, for example if a tetrahedral package having a top fin and a bottom fin that are orthogonal to each other is to be formed.

[0069] It will of course be understood that each pair of sealing jaws in making a transversal seal across the tube of packaging material is making in the same operation the top sealed edge for one of the individual packages, and the bottom sealed edge for another of the individual packages, the tube of packaging material being subsequently cut along approximately the median line of each transversal seal by any suitable means, (such as e.g. a knife 100 shown in FIG. 2), to separate the strip material into individual packages.

[0070] The skilled person realizes that a number of modifications of the embodiments described herein are possible without departing from the scope of the invention, which is defined in the appended claims.