The invention relates to a container for receiving cryogenic media and/or devices to be stored at low temperatures, preferably of below 150 kelvin, comprising an outer shell and an insulating shell which in a positionally stable manner via positioning elements is directly or indirectly connected therewith or, respectively, is directly or indirectly supported thereon, and which, optionally, is surrounded by one or several further insulating shells, wherein either the device or an inner shell for storing cryogenic media is connected to the outer shell in a positionally stable manner via fastening elements.
Cryogenic media are understood to be liquified gases, for example, helium, nitrogen, oxygen, natural gas or hydrogen. In the liquid state, the temperature of those gases usually amounts to less than 150° kelvin. For storing those media, an inner shell incorporated in an outer shell is provided.
For the temperature insulation of a container for cryogenic media, in the following referred to as a cryotank, it is suitable to insulate the inner shell as strongly and as completely as possible in order to avoid heat losses as much as possible. The clearance between the inner shell and the outer shell is evacuated in most cases. However, the inner shell must be secured in the outer shell. Suitably, this occurs in such a way that as few thermal bridges as possible are formed between the two shells. Since, however, some kind of structural elements must necessarily be formed between the inner shell and the outer shell for mounting purposes, heat losses will inevitably occur via those mounting elements.
In U.S. Pat. No. 2,926,810, for example, a tank made of an outer shell and an inner shell is illustrated, with the inner shell being connected to the outer shell via cross-struts. The cross-struts made of a material of low thermal conductivity have diameters which are as small as possible in order to keep the thermal bridges as minor as possible.
Furthermore, to provide the inner shell with an additional insulation, insulating layers and/or radiation shields can be introduced into the clearance between the outer shell and the inner shell. For example, from DE 195 46 619, a cryocontainer is known in which the inner shell is surrounded by numerous insulating mats.
Furthermore, from U.S. Pat. No. 4,988,014, a cryocontainer is known in which a heat shield made of aluminium or copper is provided between the outer shell and the inner shell. Said heat shield is suspended, just like the inner shell, from two suspension brackets in opposite end regions of the cryocontainer.
From FR 2711640, a cryocontainer comprising an inner shell and an outer shell is known, wherein pads or pillows, respectively, made of an alternately conductive material and an insulating material are arranged in the clearance.
From WO 2006/034521 A1, it is known to hold the inner shell in suspense in a contactless manner relative to an outer shell of a cryotank using permanent magnets. No further insulating layers are provided between the inner shell and the outer shell.
Magnetic insulating layers for a cryotank between an outer shell and an inner shell can be learnt from US 2006/0196876 A1, whereby insulating spaces are likewise formed between the layers or, respectively, between the layers and the outer shell and the inner shell.
From AT 502 191 B1, a cryotank is known according to which an inner shell is supported on an outer shell via a supporting structure, wherein radiation barriers exhibiting high reflectivity are provided which produce numerous thermal bridges, since the radiation barriers themselves contact the inner shell directly and are also supported directly on one another.
A cryotank of the initially described kind is known, for example, from EP 0 014 250 B1, wherein an inner shell is supported on the outer shell via holding straps composed of single elements. Several insulating shells attached to the holding straps are arranged between the inner shell and the outer shell. Said insulating shells are provided at a distance from each other and at a distance from the inner shell and the outer shell. The construction of a cryocontainer of such a type is complex and its assembly is difficult. In addition, the insulating shells put strain on the fastening elements by means of which the inner shell is attached to the outer shell.
The invention aims to avoid said disadvantages and difficulties and its object is to provide a container of the initially described kind wherein the inner shell is not only securely suspended within the outer shell and properly secured against any mechanical and thermal stress that is occuring, but which also allows easy assembly in addition to minor heat losses so that the manufacturing expenditure is low even if a plurality of insulating shells are present. A further object is to securely fix the insulating shell in the clearance between the inner shell and the outer shell while keeping a distance as constant as possible both from the inner shell and from the outer shell as well as from optionally provided further insulating shells.
According to the invention, said object is achieved in that each insulating shell has at least a two-piece design and is attached to the outer shell and/or to the device and/or to the inner shell via positioning elements which are independent of the fastening elements, with the insulating shell being spaced apart in a contactless manner from the outer shell or the inner shell or the device or a further insulating shell, respectively, whereby a gap is formed.
A substantial advantage of the invention is the fact that the cryocontainer according to the invention can exist entirely without superinsulating layers or without MLI (multi layer insulation), respectively, which involves advantages in terms of price as well as with regard to the manufacturing process.
In order to achieve an effective insulation as radiation shields, it is advantageous if the insulating shells are spaced apart from each other, whereby the insulating effect can be increased further by an intermediary vacuum. For lack of space, in particular for the application in motor vehicles, it is advantageous if distances as small as possible are formed between the insulating shells.
According to the invention, it is easily possible to avoid direct wall contact between the inner and outer shells and the insulating shell and the device in the state of rest.
Positioning elements are preferably formed from bolts.
According to another advantageous embodiment, positioning elements are designed as spring elements, in particular as helical spring elements.
Suitably, positioning elements clamp an insulating shell against the inner shell or against the outer shell and, accordingly, are supported or anchored, respectively, on the one hand, on the insulating shell and, on the other hand, on the inner shell or outer shell, respectively.
If two or more insulating shells are present, positioning elements are supported or anchored, respectively, on the one hand, on a first insulating shell and, on the other hand, on a further insulating shell adjacent to the first insulating shell.
At the locations where positioning elements are provided, the insulating shells or the outer shell, respectively, preferably have/has bulges extending alongside the positioning elements for locally receiving a positioning element, with the positioning elements being supported or anchored, respectively, in the end regions of the bulges. Thereby, it is possible to arrange the positioning elements such that they have lengths as large as possible so that heat transmissions through the positioning elements can be minimized.
According to a preferred embodiment, bolts are supported or anchored, respectively, on the device or on the inner shell or outer shell or on the insulating shell, respectively, on the one hand, by a collar provided on one of the ends thereof and, on the other hand, by a self-locking sealing ring slid onto the other end of a bolt.
A further preferred embodiment is characterized in that bolts are equipped with snap-in lugs provided at their ends which serve for being inserted into openings and for anchoring the bolts in said openings, with the openings being provided on the device or on the inner shell or outer shell or on an insulating shell, respectively.
For adjusting pretensions and/or for compensating thermal expansions, bolts are advantageously anchored with one end on the device or on the inner shell or outer shell, respectively, or on an insulating shell by means of a screw connection.
The longitudinal axis of the positioning elements is advantageously inclined toward the surface of the insulating shell or of the device or of the inner shell or outer shell, respectively, in the area of the attachment of the positioning elements.
It is also possible to form the positioning elements from magnets.
A suitable embodiment is characterized in that the positioning elements are arranged with regard to a longitudinal axis of the cryotank so as to be evenly distributed around said longitudinal axis, wherein suitably three positioning elements are arranged and distributed around the longitudinal axis.
Preferably, the insulating shell(s) is/are formed from two half shells each, which half shells are connectable to each other by a plug connection to form an insulating shell, wherein suitably each of the half shells is directly or indirectly attached to the outer shell and/or inner shell or to a further insulating shell, respectively, via positioning elements.
A further embodiment is characterized in that the insulating shell(s) is/are attached to the outer shell and/or inner shell via positioning elements, with forces securing the parts of the insulating shell relative to each other which are preferably produced by springs.
It is also possible that the parts of an insulating shell are positionally secured directly relative to each other, such as, for example, by hooks, an adhesive joint or a weld seam.
A further preferred embodiment is characterized in that positioning elements are designed as helical springs, with the helical springs being arranged in alignment with each other for supporting adjacent insulating shells and the insulating shells exhibiting access openings to the helical springs.
Preferably, a magnetizing coil is connected to the outer shell in a positionally stable manner via fastening elements.
An advantageous variant of the invention is characterized in that the insulating shells are connected both to each other and to the insulating shell designed as an inner tank and/or to the outer shell designed as an outer container via suspension belts or bands, respectively, which in particular are flexible and/or pliable, respectively.
In order to keep heat losses small, it is furthermore advantageous to design the suspension belts as long as possible.
Furthermore, it is advantageous to place the suspension belts such that the stability of the insulating shells and of the cryocontainer, respectively, is increased merely by the specific type of the meander-shaped winding and the forces resulting therefrom.
Two embodiments of the cryocontainer according to the invention are basically possible, wherein, in the first embodiment, the insulating shells are attached to the outer container and, in the second embodiment, the insulating shells are attached to the inner container. The former embodiment has advantages with regard to the insulating effect.
Further suitable variants are defined in the subclaims 22 to 39. Below, the invention is illustrated in further detail based on several exemplary embodiments which are schematically illustrated in the drawing.
A further embodiment is explained in
The cryotank depicted in longitudinal section in
In the space 9 between the outer shell and the inner shell, which may be evacuated, insulating shells 10 are provided—three in the illustrated exemplary embodiment, however, only one insulating shell 10 or an arbitrary plurality might also be provided. In order to prevent contacts between the insulating shells 10 and the inner and outer shells 1, 2, the insulating shells 10 each composed of two halves 10′ and 10″—the plane of osculation is located approximately in the centre of the length of the longitudinal axis 6 and extends transversely thereto—are fastened to the inner shell 2 or the outer shell 1 or to a further insulating shell 10, respectively, via positioning elements 11.
The positioning elements 11—which are designed as bolts—are provided in such a way that forces clamping the two parts 10′ and 10″—in the following also referred to as half shells 10′, 10″—of the insulating shell 10 against each other are produced via the positioning elements 11. According to the exemplary embodiment illustrated in
As can be learnt in particular from
The positioning elements 11 themselves are snapped in each case with one end into openings 17 of inserts 16 provided on the inner shell 2 or on the insulating shells 10, respectively, and the opposite ends penetrate through openings 17 of the insulating shells 10 or through an opening 18, respectively, of an insert 19 provided in the outer shell 1 likewise with flexible tongues, wherein collar-shaped shoulders 20 are provided for positional fixation so that the bolts 11 can also absorb compressive forces.
The positioning elements 11 are arranged so as to be evenly distributed around the longitudinal axis 6 of the cryocontainer, wherein, according to the exemplary embodiment illustrated in
The two parts 10′ and 10″ of the insulating shells are connected by a simple plug connection 21 so that safeguarding of the position of the two parts 10′, 10″ plugged into each other transversely to the longitudinal axis 6 of the cryocontainer is provided.
According to the exemplary embodiment illustrated in
According to the embodiment according to
In
In this manner, it is possible to grasp the individual insulating shells 10 using tools specifically designed therefor and place them in a correct position relative to each other in order to establish the connection between the top parts and the corresponding bottom parts 10′ and 10″ and to facilitate the assembling process. The outwardly projecting edges 32 also provide working surfaces for the tools.
It is also possible to provide other means instead of the elevations 31, for example, pegs and bushes or grooves and springs entering into an operative connection with each other.
As can be seen from
According to
In
In
Of course, any type of devices to be cooled or to be kept cool can be provided in a container according to the invention, wherein, suitably, the device itself is then attached to the outer shell via fastening elements so that no inner shell is required in that case, unless the device itself has to be surrounded by a cryogenic liquid, in which case the device is provided in an inner shell, wherein the inner shell is then arranged on the outer shell in a positionally stable manner via fastening elements.
Thus, the container according to the invention is suitable for storing superconductors, structural units of cooling systems, for storing sensitive electronic switching circuits, for cryopumps, for random material samples such as organic substances, e.g., sperm, ovocytes etc. to be stored at low temperatures.
The invention is not limited to the exemplary embodiments defined in the figures, but can be modified in various respects. As has already been indicated, it is possible, for example, to provide any number of insulating shells 10 in order to meet the various demands on the temperature insulation.
The insulating shells can also be composed of several parts, wherein portions can be slid on also along other axes than the main sliding axes of the end pieces (bumped boiler ends or parts of the insulating shells where the positioning elements are attached) of the insulating shells. Those parts are either plugged together, welded together or secured via hooks, or they are secured relative to each other by plug connections via the forces securing the two end parts relative to each other.
A person skilled in the art has free choice regarding the number of positioning elements. For example, it may be required to arrange more than three positioning elements 11 for each plane of attachment, if specific demands are made on stability, e.g., for using a cryotank in heavy construction equipment. For stabilizing an insulating shell 10, it may be advantageous to arrange at least one positioning element 11 in a way which is not radially symmetrical, with the viewing direction toward the longitudinal axis 6. Yoke elements or loops stuck to the insulating shell or to the inner shell and/or outer shell, respectively, or formed integrally therewith may also be used as positioning elements. It is essential that no direct contact between the shells occurs such as according to AT 502 191 B1.
In
Both the outer container 42 and the inner tank 43 have an essentially cylindrical basic shape, with the edges of the top and bottom surfaces, where the lateral surface merges into the top and bottom surfaces, having a rounded design. Furthermore, a spherical design of the cryocontainer or a configuration in the shape of an ellipsoid are, for example, possible.
The inner tank 43 is suspended or kept, respectively, in the outer container 42 in a positionally stable manner at its upper end via first fastening elements 45a and at its lower end via second fastening elements 45b, preferably of the same design. The first and second fastening elements or inner tank suspensions 45a, 45b, respectively, are torsionally rigid loops, however, rigid cross-struts may also be used. The fastening elements 45a, 45b may also be designed as coaxial pipes slidable or insertable into each other. The fastening elements 45a, 45b are made of carbon-fibre reinforced plastic CFK.
At least three first fastening elements 45a and at least three second fastening elements 45b are in each case provided on the opposite sides of the cryocontainer 41. They are arranged regularly with regard to the circumference, i.e., with an angular distance of 120°.
An upper first suspension bracket 52a is arranged at the poles of the cryocontainer 41 and a lower second suspension bracket 52b is arranged at the lower end, and they are firmly connected to the outer container 42. The upper first suspension bracket 52a and the lower second suspension bracket 52b are firmly connected to the outer container only as one of the final steps of the assembly. First and second suspension bolts 53a and 53b are formed on those first and second suspension brackets 52a, 52b, which suspension bolts extend inwards toward the inner tank 43. The first and second suspension bolts 53a and 53b are designed so as to be twistable in order to allow later fixing of the fastening elements 45a, 45b. In addition, space is thereby saved.
Three inner tank bolts 51a, 51b are, in each case, formed on the surface of the inner tank 43, namely in the region of the transition of the lateral surface to the top surface and bottom surface, respectively, with the inner tank bolts protruding from the surface of the inner tank 43. Those first and second inner tank bolts 51a, 51b are arranged in cavities 67 and disappear completely in those cavities. In this manner, the fastening elements 45a, 45b are prevented from sliding off the inner tank bolts 51a, 51b through the innermost insulating shell 47′, if said shell is located in its final position.
The fastening elements 45a, 45b extend between the first and second inner tank bolts 51a, 51b, respectively, and the first and second suspension bolts 53a, 53b, respectively. In this way, a positionally stable suspension of the inner tank 43 in the outer container 42 is ensured.
An evacuatable clearance 46 is thus formed between the outer container 42 and the inner tank 43. In the embodiment according to
The insulating shells 47 surround the inner tank 43 in the shape of an onionskin and run largely parallel to each other. The distance between the individual insulating shells 47 is approximately 1 to 10 mm in the area of the lateral surface and in the area of the poles of the cryocontainer 41 and should be kept as small as possible. The individual insulating shells 47 do not contact each other and are not adjacent to each other. Rather, they are completely spaced apart from each other and are interconnected merely via suspension belts 48a, 48b, which will be described later on.
A detailed view of the top side of the cryocontainer 41 is illustrated in
The fastening elements 45a, 45b are oriented radially and, respectively, intersect in their virtual extension in the longitudinal axis 44 of the cryocontainer 41.
The cryocontainer 41 and the outer container 42, respectively, exhibit a certain number of bulges 49 formed on the top side and on the bottom side. Those bulges 49 lie in the area of the inner tank bolt 51 and of the suspension bolts 53 and extend radially outwards. Suspension belts 48a, 48b, which will be described later on, and also fastening elements 45a, 45b are arranged within those bulges 49, whereby the individual insulating shells 47 are connected to each other and, respectively, to the outer container 42 or the inner tank 43 in the area of those bulges 49. Each individual insulating shell and also the outer container 42 exhibit such bulges 49, wherein the bulges 49 in the outer container 42 are correspondingly designed so as to be largest, and the bulges 49 of the individual insulating shells 47 become increasingly smaller toward the inside.
The bulges 49 serve, on the one hand, for accommodating the fasteners in the form of suspension belts 48a, 48b, which will be described later on, which fasteners are to be designed as long as possible. Moreover, the bulges serve for improving the structural integrity as well as the stability and stiffness, respectively, of the insulating shells 47 and of the outer container 42.
In
The fastening elements 45a, 45b run through notches 68 formed in each insulating shell 47. For reasons of insulation, the notches 68 are advantageously dimensioned as small as possible. The notches 68 of the individual insulating shells 47 lie in a straight line relative to each other and are arranged in alignment. The notches 68 can be formed in different sizes between the top side and the bottom side of the cryocontainer 41, depending on the assembling method of the cryocontainer 41. For example, the notches 68 for the implementation of the second fastening elements 45b, which are mounted later in the process, are larger than the notches 68 for the implementation of the first fastening elements 45a, which are mounted first.
A section through a bulge 49 is illustrated in
As has already been indicated, the individual insulating shells 47 are attached either to the inside of the outer container 42 or, in an alternative embodiment, to the outside of the inner tank 43. The attachment of the insulating shells 47 is effected via suspension belts or bands 48a, 48b, respectively, which are provided in the boundary or transition region, respectively, of the top side and the bottom side toward the lateral surface. Thus, at least 3 first and second suspension belts 48a, 48b, which are basically spaced apart uniformly, are provided on each side. Said suspension belts or bands 48a, 48b are made of a flexible pliable material of high tensile strength and low thermal conductivity, preferably of carbon fibres without matrix.
The suspension belts 48a, 48b are advantageously designed as long as possible, resulting in low heat dissipation.
As can be seen in
The suspension belts 48a, 48b are placed in a meander shape such that a force component compressing the insulating shells 47 will result. The direction of the suspension belts or bands 48a, 48b produces a force component which compresses the oppositely located corresponding insulating shells 47a, 47b, whereby lifting of the insulating shells is permitted if the suspension belts or bands 48a, 48b are attached to the outer container 42.
A further embodiment of an alternative cryocontainer 41 is shown in
In
In
As is visible in the previous figures, neither a mechanical connection, nor an operative connection of a different kind exists between the fastening elements 45a, 45b and the suspension belts 48a, 48b. The two elements are elements independent of each other and mechanically separated from each other.
In
In
Each second or lower partial shell 47b, respectively, comprises several essentially rectangular lower second positioning means in the form of elevations 81b, which positioning means are distributed regularly along the circumference thereof and are adapted to the curvature of the second partial shell 47b. Those elevations 81b exhibit, in each case, a lower edge 82b projecting obliquely upwards in an outward direction. Each first and/or upper partial shell 47a also comprises several essentially rectangular upper first positioning means in the form of elevations 81a, which positioning means are distributed regularly along the circumference and, with regard to their dimensions and their distribution and their positioning relative to each other, correspond to the lower elevations 81b and/or are associated therewith, respectively. The upper elevations 81a likewise exhibit, in each case, an edge 82a projecting obliquely downwards in an outward direction.
As can be seen in
Furthermore, the lower partial shells 47b have a continuous locking rail 83 running around the periphery in parallel and spaced apart from the end edge, which locking rail engages the outwardly projecting edge 82a of the corresponding upper partial shell 47a and is kept therein non-positively with regard to traction and pressure.
In
In this manner, it is possible to grasp the individual insulating shells 47a, 47b using tools specifically designed therefor and place them in a correct position relative to each other in order to establish the connection between the upper and the corresponding lower partial shells and to facilitate the insertion process. The outwardly projecting edges 82a, 82b also provide working surfaces for the tools.
It is also possible to design the positioning means 81 differently, for example, as pegs and bushes or grooves and springs entering into an operative connection with each other.
In addition, passages (not illustrated) to the inner tank 43 for conduits are provided in the partial shells 47a, 47b and in the outer container 42. They can be arranged, for example, along or parallel to the longitudinal axis 44.
According to
Said recess 100 is closed by a lid 58b′ after the insulating shell has been slid on.
Below, the construction and a process for assembling the first embodiment of the cryocontainer 41, as illustrated in
The process comprises the following steps, wherein the individual steps may also be performed simultaneously or in a slightly changed order:
a) Attaching a first outer container part 42a using a first outermost positioning ring 55a in such a position that the opening of the first outer container part 42a will point downwards (
b) Hooking in the three first suspension belts 48a on the inside of the first outer container part 42a at the points provided therefor, namely the outer fastening devices 65 (
c) Prepositioning the first outermost partial shell 47a′″ using a first further positioning ring 55a′″ in front of, but still outside of the opening of the first outer container part 42a in such a way that the opening of the first outermost partial shell 47a′″ will point into the same direction as the opening of the first outer container part 42a (
d) Threading the first suspension belts 48a through the recesses 70, 71, 72 and, respectively, around the clamping devices 61, 63 and the deflection element 60 of the first partial shell 47a′″, respectively (
e) Inserting the first outermost partial shell 47a′″ into the first outer container part 42a and fixing it therein using the respective positioning rings 55a′″ and 55a (
f) Threading the three first upper fastening elements 45a through the slots or notches 68, respectively, in the first outermost partial shell 47a′″ (
g) Applying an initial tension to the first suspension belts 48a (
h) Fixing the first suspension belts 48a with the first clamping devices 61, 63 (
i) Inserting two further first partial shells 47a″, 47a′, . . . by analogously repeating steps c) to h),
j) Shortening the first suspension belts 48a after installation of the innermost partial shell 47a′. One half of the cryocontainer 41 has thus been completed. The arrangement is maintained by the positioning rings 55.
k) Inserting the inner tank 43 by introducing it into the opening of the innermost first partial shell 47a′,
l) Putting the first fastening elements 45a around first inner tank bolts 51a of the inner tank 43 as soon as the inner tank 43 is close enough. This is possible because of the length of the loops 45a which is still sufficient, since they are not yet placed around the suspension bolts 53a. Steps k) and l) may be performed simultaneously or in random order.
m) Mounting a first suspension bracket 52a to the outside of the first outer container part 42a,
n) Attaching the first fastening elements 45a to first suspension bolts 53a of the first suspension bracket 52a and fixing them by twisting the first suspension bolts 53a. The inner tank 43 thus hangs from the first suspension bracket 52a.
o) Assembling the second part of the jacket of the inner tank 43 by analogously repeating assembly steps a) to j) for the three second partial shells 47b′, 47b″, 47b′″ and the second outer container part 42b, respectively. The result is an arrangement comprising the second outer container part 42b and the three second partial shells 47b′, 47b″, 47b′″ connected to each other and to the second outer container part 42b.
p) Removing all second positioning rings 55b of the second part of the jacket and sliding the second part of the jacket with the innermost second partial shell 47b′ from below over the end of the inner tank 43 which is still free from partial shells. After its assembly, said second jacket arrangement is turned upside down in order to be able to slide it from below over the inner tank 43.
q) Removing the innermost first positioning ring 55a′ of the innermost first partial shell 47a′, whereby said shell sinks down and rests on the side of the inner tank 43 which is close to the first suspension bracket 52a,
r) Lifting the innermost second partial shell 47b′ and connecting the innermost first partial shell 47a′ to the innermost second partial shell 47b′ by a snap-in or plug connection 80. Said plug connection must be dimensioned so as to be strong enough for carrying the weight of the lower innermost second partial shell 47b′ during the assembling process. The lower innermost second partial shell 47b′ can be lifted because the suspension belts 48b are designed in a flexible manner.
s) Attaching the second fastening elements 45b to the second inner tank bolt 51b of the inner tank 43 during lifting. The fastening elements 45a, 45b are prevented from sliding off by the innermost partial shell 47a′ and 47b′, as soon as said shell is in the final position. Steps r) and s) may be performed simultaneously or in random order.
t) Mounting the two further partial shells 47b″, 47b′″ by analogously repeating steps q) to r). After removal of the positioning ring 55a″, the first partial shell 47a″ sinks down until the suspension belts 48a are stretched.
u) Mounting the second outer container part 42b and welding the first outer container part 42a to the second outer container part 42b.
v) Placing a second suspension bracket 52b on the outside of the second outer container part 42b in a position opposite to the first suspension bracket 52a.
w) Putting the second fastening elements 45b onto the second suspension bolt 53b and optionally fixing them by twisting the second suspension bolts 53b.
x) Adjusting the desired initial tension in the fastening elements 45 by pulling at the suspension brackets 52.
y) Welding the two suspension brackets 52 to the outer container 42.
z) Attaching a lid for covering the suspension brackets 52 in a vacuum-tight manner.
Alternatively, the suspension brackets 52 can be supported via one shaft nut 110 each. In that case, the step of adjusting the initial tension and welding can take place simultaneously.
Number | Date | Country | Kind |
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A 1611/2006 | Sep 2006 | AT | national |
A 1348/2007 | Aug 2007 | AT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/AT07/00451 | 9/25/2007 | WO | 00 | 6/23/2009 |