Title of Invention	AN ELECTRIC CONNECTION FOR AN ELECTRICALLY CONDUCTIVE CERAMIC PART, SUCH AS A SEALING JAW AND A METHOD OF REALISING THE ELECTRIC CONNECTION
Abstract	"An electric connection for an electrically conductive ceramic part, such as a sealing jaw and a method of realising the electric connection" The disclosure relates to an electric connection for an electrically conductive ceramic part (4a, 4b) such as a sealing jaw. A first electric conductor (7a, 7b) is united with a portion of the electrically conductive ceramics (4a, 4b) by means of a foil (12) which has metallized said portion of the electrically conductive ceramics (4a, 4b) and fused together said portion with the electric conductor (7a, 7b). The disclosure further describes a method of producing such a connection. Figure 4

Title of Invention

AN ELECTRIC CONNECTION FOR AN ELECTRICALLY CONDUCTIVE CERAMIC PART, SUCH AS A SEALING JAW AND A METHOD OF REALISING THE ELECTRIC CONNECTION

Abstract

"An electric connection for an electrically conductive ceramic part, such as a sealing jaw and a method of realising the electric connection" The disclosure relates to an electric connection for an electrically conductive ceramic part (4a, 4b) such as a sealing jaw. A first electric conductor (7a, 7b) is united with a portion of the electrically conductive ceramics (4a, 4b) by means of a foil (12) which has metallized said portion of the electrically conductive ceramics (4a, 4b) and fused together said portion with the electric conductor (7a, 7b). The disclosure further describes a method of producing such a connection. Figure 4

Full Text	TECHNICAL FIELD The present invention relates to an electric connection for an electrically conductive ceramic part, such as a sealing jaw and a method of realising the electric connection. BACKGROUND ART It has long been known within packaging technology to produce packages of thermoplastic material or material coated with thermoplastic layers, for example plastic-coated paper or paperboard. The advantage inherent in these materials is that they can be fused together and sealed together in a convenient manner by surface fusion of thermoplastic layers applied against one another. By such means, it is not only possible to ensure that the packages which have been formed by folding or other means can be retained in their given configuration but also to ensure that the packages can be formed with a liquid-tight seal which protects the contents of the package and prevents the contents from leaking out. Seals of this type are most generally realised with the aid of different types of sealing jaws. If the packaging material includes an aluminium layer, it is today common to employ so-called induction sealing where the packaging material is locally subjected to a rapidly alternating magnetic field which induces a heat-generating current in the aluminium layer which in its turn heats up a thermoplastic layer in the proximity. If the packaging material does not include an aluminium layer, use is normally made of so- called impulse heating. In accordance with this method, so-called heating jaws are employed which consist of apparatuses which between them can accommodate the materials intended for sealing together and compress them during simultaneous supply of heat so that the desired parts of the compressed and mutually facing plastic layers are caused to fuse together to a tight and mechanically durable joint. The normally occurring type of such sealing jaw consists of metal strips or metal bodies disposed on support rails and which either are permanently heated or are heated on each individual sealing occasion in that an electric current is passed through them. Sealing can either be carried out with the aid of two heated sealing jaws which are urged against one another on either side of the material which is to be sealed or by one sealing jaw and a so-called abutment jaw whose purpose is merely to constitute an abutment for the heating jaw and cool the material in order that the sealing joint may rapidly be stabilised. The most commonly occurring sealing jaws in filling machines consist of heating jaws with thin metal strips disposed on an insulating ceramic material disposed on a steel rail. At the occasion of sealing, the sealing jaws are closed with great compressive force so that they accommodate between them the material which is to be sealed, whereafter a short current pulse is passed through the above-mentioned metallic strips which are momentarily heated to elevated temperature. The heat generated in the metallic strips is transferred over to the packaging material and the mutually facing thermoplastic layers are caused to fuse together. The current pulse is discontinued when a sufficient quantity of heat has been generated, whereafter the sealing jaws are opened and the sealed material is exposed. As has been described in, among others, US-A-5,682,732 and EP Application number 01108745.9, recent time has seen the introduction of sealing jaws which consist of a heating rail comprising an electrically conductive ceramic material embedded in a body which consists of an electrically insulating ceramic material. With sealing jaws of this type, there are a plurality of possibilities of forming the sealing zone into different geometric shapes. Further, it is also possible, by selecting materials of approximately the same coefficient of linear expansion, to reduce thermally dependent mechanical loads which otherwise derive from the different coefficients of temperature linear expansion of the components included. EP Application number 01108745.9 describes how it is possible to form the electrically conductive and electrically insulating components, respectively, included in the sealing jaw in order, i. al. to facilitate manufacture and assembly. The publication further discusses the cooling of the heating jaws. As is described in US-A-5,682,732, it is possible, in order to improve the electric conductive capacity of the ceramic surface locally by metallising the surface. This is done, for example, at those places where an electric conductor for power supply is to be connected to the ceramics by means of a conventional clamp connection in which the conductor is clamped against the metallised surface. However, it has proved that, in certain constructions, the transitional resistance in this connection will be of the same order of magnitude as the total resistance in the heating rail. Moreover, it has proved that, in certain constructions where the connection is located in a damp environment, the connection is afflicted by corrosion damage. This corrosion situation is even more aggravated by the fact that those materials which are employed display high electrochemical potentials which result in the fact that the connection is exposed to powerful galvanic corrosion. There is, thus, a need in the art to be able to realise a solution to the above-mentioned problems regarding the connection between the electric conductor for power supply and the electrically conductive ceramics. SUMMARY OF THE INVENTION The above objects have been attained according to the present invention by means of a connection of the type intimated by way of introduction which has been given the characterising feature that an electric conductor is united with a portion of the electrically conductive ceramics by means of a foil which has metallized said portion of the electrically conductive ceramics and fused together said portion with the electric conductor. By such means, the connection has been formed so that it connects, as a fixed unit, to the ceramic body without any loose parts needing to be clamped in position. The electric connection formed as a fixed unit further affords advantages as regards greatly reduced transitional resistances and greatly reduced sensitivity to corrosion. In a connection between two clamped-together components, the narrow gap which is inevitably formed creates an ideal space for so-called gap corrosion. In addition, the corrosion entails that the gap opens increasingly and, as a result, the transitional resistance becomes even greater. These problems are thus obviated by means of the electric connection according to the present invention. Preferred embodiments are also described herein. According to one preferred embodiment, the electric connection in encapsulated in an electrically insulating material which offers corrosion protection. By such means, it is possible to keep possible electrolyte-forming liquid away from the connection and thereby prevent any possible galvanic corrosion from damaging the connection. Given that the connection is formed in one integrated piece, it is possible to press the insulating material into a hood which covers the connection without risking this penetrating in between the contact surfaces. Advantageously, the first conductor is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof in order to give the desired electric properties. Advantageously, the unification is facilitated in that the foil is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof. It has proved that such a foil possesses positive properties as regards adhesion and metallization both to the ceramic surface and to the metallic surface of the conductor. The above-outlined objects have also been attained by means of a method of realising an electric connection between an electrically conductive ceramic part, such as a sealing jaw, and an electric conductor comprising the steps of: disposing, on a ceramic surface, a metallization foil for realising a metallized surface, providing an electric conductor in contact with the metallization foil, and subjecting the metallization foil to heat so that this metallizes the ceramic surface and units it with the electric conductor. By such means, there will be obtained an electric connection of the type which has been described above and which enjoys those advantages as were mentioned in connection with the description of the electric connection per se. Preferred embodiments of the method according to the present invention are described herein. According to one preferred embodiment, the metallization foil is subjected to heat while, at the same time, being subjected to a powerful partial vacuum, as in a vacuum chamber or the like. This is carried out in order to avoid the risk that the foil material reacts with oxygen and other components in the air. The thus realized electric connection is mechanically strong and may be employed at elevated operational temperatures of up to 600-700°C. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention will now be described in greater detail hereinbelow, with reference to the accompanying schematic Drawings which, for purposes of exemplification, show one currently preferred embodiment of the present invention. In the accompanying Drawings: Fig. 1 is a schematic Drawing of a sealing jaw; Fig. 2 shows a sealing jaw according to one preferred embodiment seen straight from the side; Fig. 3 shows the sealing jaw according to Fig. 2 seen straight from the front; and Fig. 4 shows, in perspective, one end of the sealing jaw illustrated in Figs. 2 and 3. DETAILED DESCRIPTION OF ONE PREFERRED EMBODIMENT As is schematically apparent from Fig. 1, the sealing jaw comprises a body 1, for example, of aluminium in which there are two cooling ducts 2a, 2b for the continuous or intermittent through flow of a coolant. In the body 1, there are further ceramic rods 3a, 3b, 4a, 4b which extend along the longitudinal direction A of the sealing jaw (see Fig. 1 and Fig. 3) in grooves 5a, Sb in the body 1. These ceramic rods consist of an electrically insulating ceramic 3a, 3b and an electrically conductive ceramics 4a, 4b which, by the insulating ceramics 3 a, 3b, is electrically insulated from remaining components in the sealing jaw and its ambient surroundings. Fig. 1 also schematically shows an elongate recess 6 which is intended to receive a knife or the like on employing a sealing joint in filling machine. Figs. 2-4 show one preferred embodiment where a complete piece 3 of an electrically insulating ceramics material carries two elongate rods 4a, 4b of an electrically conductive ceramics material. For example, use may be made as electrically insulating material of a mixture of zirconium dioxide (Zr02) and silicon carbide (SiC) and as electrically conductive material use may be made of a mixture of titanium boride (TiB2) and silicon carbide (SiC). In the insulating material, Zr02 constitutes of the order of magnitude of 10 to 50 volume per cent, preferably 20 to 40 volume per cent, and most preferably approximately 30 volume per cent. In the conductive material, TiB2 constitutes of the order of magnitude of 20 to 60 volume per cent, preferably 35 to 55 volume per cent, and most preferably approximately 45 volume per cent. At the ends, the rods 4a, 4b of the electrically conductive material are disposed to be connected to a current source by the intermediary of which an electric current is intended to be supplied to the rods 4a, 4b for heating them. The connections (see Fig. 4) comprise two plates 7a, 7b of silver or a silver alloy, a clamping sleeve 8 which is disposed to be clamped by means of a screw 9 against a lower insert 10 and thereby mechanically offload the current connection, as well as a more powerful, second electric conductor 11 to which the silver plates 7a, 7b are hard soldered and which are disposed to be connected to the above-mentioned current source. The second electric conductor 11 is produced from a silver alloy or some other metal of low resistivity, such as silver-plated copper or the like. The clamping sleeve 8 and the lower insert 10 are produced from an electrically insulating polymer material, such as different plastics, silicon or the like. These types of material moreover display a certain flexibility, with the result that they can absorb certain movements in the connection without damaging the contacts. In order to ensure that the contact resistance between the contact plates 7a, 7b and the ceramics 4a, 4b is as low as possible, the ceramic material 4a, 4b is metallised or metal plated at those points where the silver plates 7a, 7b are to be connected to the ceramic material 4a, 4b. This metal plating is put into effect at approx. 700-800°C at a powerful vacuum (approx. 10-6 mbar) in order, in aL, to avoid reaction with oxygen. The plating is carried out by means of a thin, foil shaped, Ag/Cu/Ti-based solder 12. In that the contact plates 7a, 7b are held against the connecting surface of the ceramic material 4a, 4b in connection with this plating operation, the contact plates 7a, 7b will be soldered or welded together with the plated surface and thereby form a connection which is of one piece manufacture. The selected solder 12 has a good wetting capacity towards the ceramic surface and good adhesive capacity against the contact plates 7a, 7b. By producing, in this manner, an electric connection which encompasses the ceramic rods 4a, 4b, the contact plates 7a, 7b and the solder 12 which metallizes the ceramic surface and welds the contact plates 7a, 7b to the ceramic surface, it has become possible to realise a complete unit which may thereafter be protected against moisture and other factors which increase the risk of corrosion damage. For example, it is possible to supply silicon, fat or other insulating material to the space beneath the clamping sleeve 8 in order to prevent moisture from penetrating and causing corrosion damage. Since there is no gap or the like between the electric conductor 7a, 7b and the metallised surface of the ceramic rods 4a, 4b, there is no appreciable risk that this insulating material will influence the quality of the electric connection. In prior art designs and constructions with clamp connections, it has not been possible to supply any such insulating material, since this then risks opening the gap and penetrating in between the plates and thereby negatively affecting the quality of the connection. Above all, this is a problem when use is made of materials which have a relatively low level of mechanical strength and as a result cannot be clamped together using any appreciable force. By separating the connection between the ceramic rods 4a, 4b and the first electric conductor 7a, 7b from the connection between the first electric conductor 7a, 7b and the further connected connection 11, it is possible to design the first contact in an optimal manner in relation to its physical circumstances and conditions and the second contact optimally in relation to its circumstances and conditions. Since the first contact has been realised in the manner according to the present invention directly in the metallization of the ceramics, this can be subjected to relatively elevated temperatures without being damaged. As a result, it is, for example, possible to employ hard soldering for the second contact without the risk that the first contact is damaged. A person skilled in the art will readily perceive that numerous modifications of the embodiments of the present invention described herein are possible without departing from the scope of the present invention as this is defined in the appended Claims, For example, it is possible to design the hood which surrounds the connection in a large number of different ways as long as it covers the connection to a sufficiently large extent and retains the corrosion-protective material around the connection. In addition, other concentrations of the components included in the ceramics are conceivable. It is also conceivable to employ other ceramic materials possessing corresponding electric properties. WE CLAM 1. An electric connection for an electrically conductive ceramic part, such as a sealing jaw, characterised in that a first electric conductor (7a, 7b) is united with a portion (4a, 4b) of the electrically conductive ceramics (4) by means of a foil (12) which has metallized said portion (4a, 4b) of the electrically conductive ceramics (4) and fused together said portion (4a, 4b) with the electric conductor (7a, 7b). 2. The electric connection as claimed in claim 1, which is encapsulated in an electrically insulating material affording corrosion protection. 3. The electric connection as claimed in claim 1 or 2, wherein said first electric conductor (7a, 7b) is connected to a second electric conductor (11) in that the electric conductors are united. 4. The electric connection as claimed in claim 3, wherein said connection between the first conductor (7a, 7b) and the second conductor (11) is encapsulated in an electrically insulating material affording corrosion protection. 5. The electric connection as claimed in claim 2 or 4, wherein said electrically insulating material is a polymer material. 6. The electric connection as claimed in any one of claims 1 to 5, wherein the electrically conductive ceramics (4a, 4b) consist of a mixture of titanium boride and silicon carbide. 7. The electric connection as claimed in any one of claims 1 to 6, wherein the insulating ceramics (3a, 3b) consist of a mixture of zirconium oxide and silicon carbide. 8. The electric connection as claimed in any one of Claims 1 to 7, wherein the first conductor (7a, 7b) is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof. 9. The electric connection as claimed in any one of the preceding claims, wherein the foil (12) is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof. 10. A method of realising an electric connection for an electrically conductive ceramic part, such as a sealing jaw, characterised in that it comprises the steps of: disposing, on a ceramic surface (4a, 4b) a metallization foil (12) for realising a metallized surface, disposing an electric conductor (7a, 7b) in contact with the metallization foil, and subjecting the metallization foil (12) for heat so that this metallizes the ceramic surface (4a, 4b) and units it with the electric conductor (7a, 7b). 11. The method as claimed in claim 10, wherein the metallization foil (12) is exposed to heat under partial vacuum. 12. The method as claimed in claim 10 or 11, comprising the step of encapsulating the union between the ceramic surface (4a, 4b) and the electric conductor (7a, 7b) in an electrically insulating material affording corrosion protection. 13. The method as claimed in any one of claims 10 to 12, comprising the step of connecting said first electric conductor (7a, 7b) to a second electric conductor (11) in that the electric conductors are compressed to abutment against one another. 14. The method as claimed in claim 13, comprising the step of encapsulating said connection between the first conductor (7a, 7b) and the second conductor (11) in an electrically insulating material affording corrosion protection. 15. The method as claimed in claim 12 or 14, comprising the step of selecting, as said electrically insulating material, a polymer material. 16. The method as claimed in any one of claims 10 to 15, comprising the step of selecting, as the electrically conductive ceramics (4a, 4b) a mixture of titanium boride and silicon carbide. 17. The method as claimed in any one of claims 10 to 16, comprising the step of selecting, as the insulating ceramics (3a, 3b), a mixture of zirconium oxide and silicon carbide. 18. The method as claimed in any one of claims 10 to 17, comprising the step of selecting, for the production of the first conductor (7a, 7b) a metal from the group essentially comprising silver, copper, titanium and optional combinations thereof. 19. The method as claimed in any one of claims 10 to 18, comprising the step of selecting, for the production of the foil (12), a metal from the group essentially comprising silver, copper, titanium and optional combinations thereof. Dated this 12 day of May 2005

Full Text

TECHNICAL FIELD
The present invention relates to an electric connection for an electrically conductive ceramic part, such as a sealing jaw and a method of realising the electric connection.
BACKGROUND ART
It has long been known within packaging technology to produce packages of thermoplastic material or material coated with thermoplastic layers, for example plastic-coated paper or paperboard. The advantage inherent in these materials is that they can be fused together and sealed together in a convenient manner by surface fusion of thermoplastic layers applied against one another. By such means, it is not only possible to ensure that the packages which have been formed by folding or other means can be retained in their given configuration but also to ensure that the packages can be formed with a liquid-tight seal which protects the contents of the package and prevents the contents from leaking out. Seals of this type are most generally realised with the aid of different types of sealing jaws. If the packaging material includes an aluminium layer, it is today common to employ so-called induction sealing where the packaging material is locally subjected to a rapidly alternating magnetic field which induces a heat-generating current in the aluminium layer which in its turn heats up a thermoplastic layer in the proximity. If the packaging material does not include an aluminium layer, use is normally made of so- called impulse heating. In accordance with this method, so-called heating jaws are employed which consist of apparatuses which between them can accommodate the materials intended for sealing together and compress them during simultaneous supply of heat so that the desired parts of the compressed and mutually facing plastic layers are caused to fuse together to a tight and mechanically durable joint. The normally occurring type of such sealing jaw consists of metal strips or metal bodies disposed on support rails and which either are permanently heated or are heated on each individual sealing occasion in that an electric current is passed through them. Sealing can either be carried out with the aid of two heated sealing jaws which are urged against one another

on either side of the material which is to be sealed or by one sealing jaw and a so-called abutment jaw whose purpose is merely to constitute an abutment for the heating jaw and cool the material in order that the sealing joint may rapidly be stabilised. The most commonly occurring sealing jaws in filling machines consist of heating jaws with thin metal strips disposed on an insulating ceramic material disposed on a steel rail. At the occasion of sealing, the sealing jaws are closed with great compressive force so that they accommodate between them the material which is to be sealed, whereafter a short current pulse is passed through the above-mentioned metallic strips which are momentarily heated to elevated temperature. The heat generated in the metallic strips is transferred over to the packaging material and the mutually facing thermoplastic layers are caused to fuse together. The current pulse is discontinued when a sufficient quantity of heat has been generated, whereafter the sealing jaws are opened and the sealed material is exposed.
As has been described in, among others, US-A-5,682,732 and EP Application number 01108745.9, recent time has seen the introduction of sealing jaws which consist of a heating rail comprising an electrically conductive ceramic material embedded in a body which consists of an electrically insulating ceramic material. With sealing jaws of this type, there are a plurality of possibilities of forming the sealing zone into different geometric shapes. Further, it is also possible, by selecting materials of approximately the same coefficient of linear expansion, to reduce thermally dependent mechanical loads which otherwise derive from the different coefficients of temperature linear expansion of the components included.
EP Application number 01108745.9 describes how it is possible to form the electrically conductive and electrically insulating components, respectively, included in the sealing jaw in order, i. al. to facilitate manufacture and assembly. The publication further discusses the cooling of the heating jaws.
As is described in US-A-5,682,732, it is possible, in order to improve the electric conductive capacity of the ceramic surface locally by metallising the surface. This is done, for example, at those places where an electric conductor for power supply is to be connected to the ceramics by means of a conventional clamp connection in which the conductor is clamped against the metallised surface. However, it has proved that, in

certain constructions, the transitional resistance in this connection will be of the same order of magnitude as the total resistance in the heating rail. Moreover, it has proved that, in certain constructions where the connection is located in a damp environment, the connection is afflicted by corrosion damage. This corrosion situation is even more aggravated by the fact that those materials which are employed display high electrochemical potentials which result in the fact that the connection is exposed to powerful galvanic corrosion.
There is, thus, a need in the art to be able to realise a solution to the above-mentioned problems regarding the connection between the electric conductor for power supply and the electrically conductive ceramics.
SUMMARY OF THE INVENTION
The above objects have been attained according to the present invention by means of a connection of the type intimated by way of introduction which has been given the characterising feature that an electric conductor is united with a portion of the electrically conductive ceramics by means of a foil which has metallized said portion of the electrically conductive ceramics and fused together said portion with the electric conductor.
By such means, the connection has been formed so that it connects, as a fixed unit, to the ceramic body without any loose parts needing to be clamped in position. The electric connection formed as a fixed unit further affords advantages as regards greatly reduced transitional resistances and greatly reduced sensitivity to corrosion. In a connection between two clamped-together components, the narrow gap which is inevitably formed creates an ideal space for so-called gap corrosion. In addition, the corrosion entails that the gap opens increasingly and, as a result, the transitional resistance becomes even greater. These problems are thus obviated by means of the electric connection according to the present invention.
Preferred embodiments are also described herein.
According to one preferred embodiment, the electric connection in encapsulated in an electrically insulating material which offers corrosion protection.

By such means, it is possible to keep possible electrolyte-forming liquid away from the connection and thereby prevent any possible galvanic corrosion from damaging the connection. Given that the connection is formed in one integrated piece, it is possible to press the insulating material into a hood which covers the connection without risking this penetrating in between the contact surfaces.
Advantageously, the first conductor is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof in order to give the desired electric properties.
Advantageously, the unification is facilitated in that the foil is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof. It has proved that such a foil possesses positive properties as regards adhesion and metallization both to the ceramic surface and to the metallic surface of the conductor.
The above-outlined objects have also been attained by means of a method of realising an electric connection between an electrically conductive ceramic part, such as a sealing jaw, and an electric conductor comprising the steps of: disposing, on a ceramic surface, a metallization foil for realising a metallized surface, providing an electric conductor in contact with the metallization foil, and subjecting the metallization foil to heat so that this metallizes the ceramic surface and units it with the electric conductor.
By such means, there will be obtained an electric connection of the type which has been described above and which enjoys those advantages as were mentioned in connection with the description of the electric connection per se.
Preferred embodiments of the method according to the present invention are described herein.
According to one preferred embodiment, the metallization foil is subjected to heat while, at the same time, being subjected to a powerful partial vacuum, as in a vacuum chamber or the like. This is carried out in order to avoid the risk that the foil material reacts with oxygen and other components in the air. The thus realized electric connection is mechanically strong and may be employed at elevated operational temperatures of up to 600-700°C.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present invention will now be described in greater detail hereinbelow, with reference to the accompanying schematic Drawings which, for purposes of exemplification, show one currently preferred embodiment of the present invention. In the accompanying Drawings:
Fig. 1 is a schematic Drawing of a sealing jaw;
Fig. 2 shows a sealing jaw according to one preferred embodiment seen straight from the side;
Fig. 3 shows the sealing jaw according to Fig. 2 seen straight from the front; and
Fig. 4 shows, in perspective, one end of the sealing jaw illustrated in Figs. 2 and 3.
DETAILED DESCRIPTION OF ONE PREFERRED EMBODIMENT
As is schematically apparent from Fig. 1, the sealing jaw comprises a body 1, for example, of aluminium in which there are two cooling ducts 2a, 2b for the continuous or intermittent through flow of a coolant.
In the body 1, there are further ceramic rods 3a, 3b, 4a, 4b which extend along the longitudinal direction A of the sealing jaw (see Fig. 1 and Fig. 3) in grooves 5a, Sb in the body 1. These ceramic rods consist of an electrically insulating ceramic 3a, 3b and an electrically conductive ceramics 4a, 4b which, by the insulating ceramics 3 a, 3b, is electrically insulated from remaining components in the sealing jaw and its ambient surroundings.
Fig. 1 also schematically shows an elongate recess 6 which is intended to receive a knife or the like on employing a sealing joint in filling machine.
Figs. 2-4 show one preferred embodiment where a complete piece 3 of an electrically insulating ceramics material carries two elongate rods 4a, 4b of an electrically conductive ceramics material. For example, use may be made as electrically insulating material of a mixture of zirconium dioxide (Zr02) and silicon carbide (SiC) and as electrically conductive material use may be made of a mixture of titanium boride (TiB2) and silicon carbide (SiC). In the insulating material, Zr02 constitutes of the order of

magnitude of 10 to 50 volume per cent, preferably 20 to 40 volume per cent, and most preferably approximately 30 volume per cent. In the conductive material, TiB2 constitutes of the order of magnitude of 20 to 60 volume per cent, preferably 35 to 55 volume per cent, and most preferably approximately 45 volume per cent.
At the ends, the rods 4a, 4b of the electrically conductive material are disposed to be connected to a current source by the intermediary of which an electric current is intended to be supplied to the rods 4a, 4b for heating them. The connections (see Fig. 4) comprise two plates 7a, 7b of silver or a silver alloy, a clamping sleeve 8 which is disposed to be clamped by means of a screw 9 against a lower insert 10 and thereby mechanically offload the current connection, as well as a more powerful, second electric conductor 11 to which the silver plates 7a, 7b are hard soldered and which are disposed to be connected to the above-mentioned current source. The second electric conductor 11 is produced from a silver alloy or some other metal of low resistivity, such as silver-plated copper or the like. The clamping sleeve 8 and the lower insert 10 are produced from an electrically insulating polymer material, such as different plastics, silicon or the like. These types of material moreover display a certain flexibility, with the result that they can absorb certain movements in the connection without damaging the contacts.
In order to ensure that the contact resistance between the contact plates 7a, 7b and the ceramics 4a, 4b is as low as possible, the ceramic material 4a, 4b is metallised or metal plated at those points where the silver plates 7a, 7b are to be connected to the ceramic material 4a, 4b. This metal plating is put into effect at approx. 700-800°C at a powerful vacuum (approx. 10-6 mbar) in order, in aL, to avoid reaction with oxygen. The plating is carried out by means of a thin, foil shaped, Ag/Cu/Ti-based solder 12.
In that the contact plates 7a, 7b are held against the connecting surface of the ceramic material 4a, 4b in connection with this plating operation, the contact plates 7a, 7b will be soldered or welded together with the plated surface and thereby form a connection which is of one piece manufacture. The selected solder 12 has a good wetting capacity towards the ceramic surface and good adhesive capacity against the contact plates 7a, 7b.
By producing, in this manner, an electric connection which encompasses the ceramic rods 4a, 4b, the contact plates 7a, 7b and the solder 12 which metallizes the ceramic surface and welds the contact plates 7a, 7b to the ceramic surface, it has become

possible to realise a complete unit which may thereafter be protected against moisture and other factors which increase the risk of corrosion damage.
For example, it is possible to supply silicon, fat or other insulating material to the space beneath the clamping sleeve 8 in order to prevent moisture from penetrating and causing corrosion damage. Since there is no gap or the like between the electric conductor 7a, 7b and the metallised surface of the ceramic rods 4a, 4b, there is no appreciable risk that this insulating material will influence the quality of the electric connection. In prior art designs and constructions with clamp connections, it has not been possible to supply any such insulating material, since this then risks opening the gap and penetrating in between the plates and thereby negatively affecting the quality of the connection. Above all, this is a problem when use is made of materials which have a relatively low level of mechanical strength and as a result cannot be clamped together using any appreciable force.
By separating the connection between the ceramic rods 4a, 4b and the first electric conductor 7a, 7b from the connection between the first electric conductor 7a, 7b and the further connected connection 11, it is possible to design the first contact in an optimal manner in relation to its physical circumstances and conditions and the second contact optimally in relation to its circumstances and conditions. Since the first contact has been realised in the manner according to the present invention directly in the metallization of the ceramics, this can be subjected to relatively elevated temperatures without being damaged. As a result, it is, for example, possible to employ hard soldering for the second contact without the risk that the first contact is damaged.
A person skilled in the art will readily perceive that numerous modifications of the embodiments of the present invention described herein are possible without departing from the scope of the present invention as this is defined in the appended Claims,
For example, it is possible to design the hood which surrounds the connection in a large number of different ways as long as it covers the connection to a sufficiently large extent and retains the corrosion-protective material around the connection.
In addition, other concentrations of the components included in the ceramics are conceivable. It is also conceivable to employ other ceramic materials possessing corresponding electric properties.

WE CLAM
1. An electric connection for an electrically conductive ceramic part, such as a sealing
jaw, characterised in that a first electric conductor (7a, 7b) is united with a portion (4a,
4b) of the electrically conductive ceramics (4) by means of a foil (12) which has
metallized said portion (4a, 4b) of the electrically conductive ceramics (4) and fused
together said portion (4a, 4b) with the electric conductor (7a, 7b).
2. The electric connection as claimed in claim 1, which is encapsulated in an electrically insulating material affording corrosion protection.
3. The electric connection as claimed in claim 1 or 2, wherein said first electric conductor (7a, 7b) is connected to a second electric conductor (11) in that the electric conductors are united.
4. The electric connection as claimed in claim 3, wherein said connection between the first conductor (7a, 7b) and the second conductor (11) is encapsulated in an electrically insulating material affording corrosion protection.
5. The electric connection as claimed in claim 2 or 4, wherein said electrically insulating material is a polymer material.
6. The electric connection as claimed in any one of claims 1 to 5, wherein the electrically conductive ceramics (4a, 4b) consist of a mixture of titanium boride and silicon carbide.
7. The electric connection as claimed in any one of claims 1 to 6, wherein the insulating ceramics (3a, 3b) consist of a mixture of zirconium oxide and silicon carbide.
8. The electric connection as claimed in any one of Claims 1 to 7, wherein the first conductor (7a, 7b) is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof.

9. The electric connection as claimed in any one of the preceding claims, wherein the foil (12) is produced from a metal which is selected from the group essentially comprising silver, copper, titanium and optional combinations thereof.
10. A method of realising an electric connection for an electrically conductive ceramic part, such as a sealing jaw, characterised in that it comprises the steps of:
disposing, on a ceramic surface (4a, 4b) a metallization foil (12) for realising a
metallized surface,
disposing an electric conductor (7a, 7b) in contact with the metallization foil, and subjecting the metallization foil (12) for heat so that this metallizes the ceramic
surface (4a, 4b) and units it with the electric conductor (7a, 7b).
11. The method as claimed in claim 10, wherein the metallization foil (12) is exposed to heat under partial vacuum.
12. The method as claimed in claim 10 or 11, comprising the step of encapsulating the union between the ceramic surface (4a, 4b) and the electric conductor (7a, 7b) in an electrically insulating material affording corrosion protection.
13. The method as claimed in any one of claims 10 to 12, comprising the step of connecting said first electric conductor (7a, 7b) to a second electric conductor (11) in that the electric conductors are compressed to abutment against one another.
14. The method as claimed in claim 13, comprising the step of encapsulating said connection between the first conductor (7a, 7b) and the second conductor (11) in an electrically insulating material affording corrosion protection.
15. The method as claimed in claim 12 or 14, comprising the step of selecting, as said electrically insulating material, a polymer material.

16. The method as claimed in any one of claims 10 to 15, comprising the step of
selecting, as the electrically conductive ceramics (4a, 4b) a mixture of titanium boride
and silicon carbide.
17. The method as claimed in any one of claims 10 to 16, comprising the step of selecting, as the insulating ceramics (3a, 3b), a mixture of zirconium oxide and silicon carbide.
18. The method as claimed in any one of claims 10 to 17, comprising the step of selecting, for the production of the first conductor (7a, 7b) a metal from the group essentially comprising silver, copper, titanium and optional combinations thereof.
19. The method as claimed in any one of claims 10 to 18, comprising the step of selecting, for the production of the foil (12), a metal from the group essentially comprising silver, copper, titanium and optional combinations thereof.
Dated this 12 day of May 2005

Documents:

0904-chenp-2005 abstract duplicate.pdf

0904-chenp-2005 claims duplicate.pdf

0904-chenp-2005 description (complete) duplicate.pdf

0904-chenp-2005 drawings duplicate.pdf

904-chenp-2005-abstract.pdf

904-chenp-2005-claims.pdf

904-chenp-2005-correspondnece-others.pdf

904-chenp-2005-correspondnece-po.pdf

904-chenp-2005-description(complete).pdf

904-chenp-2005-drawings.pdf

904-chenp-2005-form 1.pdf

904-chenp-2005-form 26.pdf

904-chenp-2005-form 3.pdf

904-chenp-2005-form 5.pdf

904-chenp-2005-form18.pdf

904-chenp-2005-pct.pdf

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Patent Number

220085

Indian Patent Application Number

904/CHENP/2005

PG Journal Number

30/2008

Publication Date

25-Jul-2008

Grant Date

15-May-2008

Date of Filing

12-May-2005

Name of Patentee

TETRA LAVAL HOLDINGS & FINANCE SA

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	SELBERG, Hans
2	INGVERT, Claes
3	NILSSON, Tommy
4	BOCKERMAN, Bjorn

PCT International Classification Number

B29C 65/22

PCT International Application Number

PCT/SE2003/001735

PCT International Filing date

2003-11-11

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0203367-8	2002-11-14	Sweden