The invention relates to a press connection system with fittings, a press tool, inserts therefore and a tubing system. Fittings are used to connect sections of pipes or tubes as part of a tubing system. Pressed connections need a mechanical or electrical press tool to deform the fitting and press or crimp the fitting to a tube inserted in the fitting. To enable multiple diameters of tubing systems, press tools can have inserts adapted to different diameters of the fittings and the tubes.
EP 3 015 751 discloses a fitting for connecting to a tubular element by a tubing connection created by a deformation of the fitting with a press tool. In general, each fitting is designed to match with a specific diameter of the tubes of the tubing system and it is necessary to provide for each specific diameter of a tube a corresponding fitting.
Especially in the two major systems with imperial sizes and metric sizes of tubing systems it is common to require the use of either imperial or metric fittings and the corresponding press tools with press parts. For example, a ¾″ press fitting is used with ¾″ press parts of a press tool on a fitting for a ¾″ tube diameter. For a 18 mm tube diameter, a 18 mm press fitting with a press tool for 18 mm is used.
This leads to many different parts to be provided and stocked to serve the needs in all diameters.
Following a first invention, a press connection system comprises a press tool, a fitting and at least a first tube, the press tool having at least two parts which can be moved relative to each other from a wide position B in close contact with a deformation zone on the fitting arranged between the parts to a narrow position C to act with force on the deformation zone of the fitting. To create a secure mechanical connection between the fitting and the first tube, the parts are designed for pressing the deformation zone of a first outer fitting diameter and of a first inner fitting diameter on the first tube of a first tube diameter inserted in the fitting. To be able to insert the first tube in the fitting, the first tube diameter is smaller than the first inner fitting diameter.
The press connection system is such, that the deformation zone of the fitting with the first outer fitting diameter is pressed either on a first tube of a first tube diameter or to a second tube of a second tube diameter, the second tube diameter being smaller than the first tube diameter.
The main purpose of the concept is to use the same fitting for either a tube system with imperial tubes or for a tube system with metric tubes. Thus, the inventive concept concerns mainly the pressing of an imperial fitting onto a metric tube. With this concept, the number of fittings which have to be provided, can significantly be reduced.
In one embodiment, the difference between the first tube diameter and the second tube diameter and/or the difference between the first inner fitting diameter and the second tube diameter is between 0.015 and 1.0 mm.
If the difference in size is too big, the deformation of the deformation zone will not lead to a sufficient strong connection allowing also a tight connection with a sealing element arranged next to or within the deformation zone.
With a difference between the first tube diameter and the second tube diameter and/or the difference between the first inner fitting diameter and the second tube diameter between 0.25 and 0.95 mm, the range of the modes of use of a fitting with such a connection is further improved in view of the stability of the connection.
A further improvement can be expected if the difference between the first tube diameter and the second tube diameter and/or the difference between the first inner fitting diameter and the second tube diameter is not more than 0.76 mm.
Still further, a difference between the first tube diameter and the second tube diameter and/or the difference between the first inner fitting diameter and the second tube diameter is between 0.35 and 0.51 mm.
Preferably, to connect a tube of the second tube diameter to the fitting instead of a tube of the first tube diameter, a deformation distance of the press tool is increased. The deformation distance between the wide starting deformation position B of a diameter Ds corresponding to a loose contact with the deformation zone of the fitting and with a narrow final deformation position C of a diameter of full load contact with the deformed deformation zone to connect the fitting to a tube of the first tube diameter is not sufficient to create a press connection to connect the tube with the second tube diameter to the fitting. The deformation distance is increased at least by the amount of the difference between the difference in diameter of the first and the second tube.
To reduce the number of press tools needed, at least one of the parts of the press tool can be formed as a mother jaw with an exchangeable insert, a first insert being configured to reach a final position C to establish a press connection on a first tube of a first outer tube diameter, a second insert being designed to be placed on the fitting with a first outer fitting diameter and to reach a final position to establish a press connection on a second tube of a second outer tube diameter smaller than the first outer tube diameter.
Another aspect of the invention is directed to a press tool such as a press jaw or a press sling, having at least two parts which can be moved relative to each other to act with force on a deformation zone of a fitting arranged between the parts. The parts are arranged in a wide starting deformation position B corresponding to a loose contact with the deformation zone having a starting opening diameter Ds. At the narrow final deformation position B corresponding to a load contact with the deformed deformation zone, there is a final opening diameter Df between the parts. The press jaw or the press sling has a special geometry of a press surface, the geometry being such that it provides at least a part of an opening with an opening diameter Ds corresponding to a nominally corresponding first outer fitting diameter R11, the geometry further being such that the nominally end position C of the press jaw or the press sling for the tube of the second tube diameter R23 can be reached.
The inventors have found out, that if an imperial size fitting would be crimped to a metric size tube to be connect with the imperial fitting using a crimping tool for metric size fittings instead of for imperial size fittings, the imperial size fitting would collapse, as the imperial size fitting cannot apply the same form along the complete perimeter as a metric size fitting. Following the invention, an imperial size fitting would be crimped to a metric size tube to be connect with the imperial fitting using a crimping tool for imperial size fittings but allowing to reach an end position of a metric size fitting.
Preferably, the press tool can have a difference between the starting opening diameter Ds and a final opening diameter Df between 0.5 mm and 1.5 mm. The sufficient big difference allows to reach the final end position of the deformation zone to create a press connection.
Another invention concerns an insert of a press tool for fittings and tubes, the insert having insert connection means to be connected to corresponding connecting means of the press tool, the insert is designed for pressing a fitting of a first outer fitting diameter for a first tube of a first outer tube diameter on a second tube of a second tube diameter, the diameter of the second tube being smaller than the first outer tube diameter.
Preferably, the insert can have a special geometry of a press surface allowing pressing the fitting for a first tube of a first tube diameter on a second tube of a second tube diameter smaller than the first tube diameter, the press geometry being such that the insert provides at least a part of an opening with an opening diameter nominally corresponding to a first outer fitting diameter the insert is defined being used with and the geometry further being such that the nominally end position C of the insert for the tube of the second tube diameter can be reached.
Again, the insert allows to be placed on a first fitting with a first outer diameter as it is used for tubes of the first tube diameter although tubes of a second diameter are connected to the first fitting. To obtain a sufficient deformation of the first fitting with the second tube, the press tool has increased press distance.
To allow the exchange of the inserts, the insert can be releasable connectable to connecting means of a press tool.
Another aspect of the invention is a tubing system comprising a first tube having a first tube end of a first outer diameter, further comprising at least one fitting with a first fitting end of a first inner diameter to receive the first tube end and with a second fitting end of a second inner fitting diameter to receive another first tube end, the fitting further having a first outer diameter at the first fitting end and a second outer fitting diameter at the second fitting end, the first inner diameter of the first fitting end to receive the first tube end is the same or is substantially the same as the second inner diameter of the second fitting end, the first outer diameter of the first fitting end is the same or is substantially the same as the second outer diameter of the second fitting end, the first fitting end and the second fitting end having a radial deformation zone to fix the fitting at the first tube forming a connection between them after a deformation of the deformation zone.
To avoid the use of numerous fittings of different sizes for tubes of different sizes, instead of the first tube with a tube end of a first tube diameter, a second tube having a second tube end of a second outer diameter is provided the second tube end has a second outer diameter smaller than the first outer diameter of the first tube end and the difference between the first outer diameter of the first fitting end and/or the second outer diameter of the second fitting end outside the deformation zone on one hand and the first outer diameter of the first fitting end and/or the second outer diameter of the second fitting end within the deformation zone to connect the first tube with the first diameter to the fitting on the other hand is increased at least by the amount of the difference between the difference in diameter of the first and the second tube end to connect the tube with the second tube diameter to the fitting.
Preferably, the difference between the first outer diameter of the first tube end and the second outer diameter of the second tube end can be between 0.1 mm and 1.0 mm.
Still another object of the invention is the use of a fitting and of a first and a second tube to be connected with the fitting, the first tube having a first tube end of a first outer diameter and at least a second tube having a second tube end of a second outer diameter, the fitting having a first fitting end of a first inner diameter to receive the first tube end and having a second fitting end of a second inner fitting diameter to receive the second tube end, the fitting further having a first outer diameter at the first fitting end and a second outer fitting diameter at the second fitting end, the first inner diameter of the first fitting end to receive the first tube end is the same or is substantially the same as the second inner diameter of the second fitting end to receive the second tube end, the first outer diameter of the first fitting end is the same or is substantially the same as the second outer diameter of the second fitting end, the first fitting end and the second fitting end having a radial deformation zone to fix the fitting and the first and/or the second tube together forming a connection between them after a deformation of the deformation zone. The fitting is connected to either the first tube at the first tube end of the first outer diameter or to the second tube at the second tube end of the second outer diameter, the second outer diameter of the second tube end being smaller than the first outer diameter of the first tube end.
Preferably, the fitting is adapted to receive a first tube of imperial size as well as a second tube of metric size.
The use of the fitting designed to be used with a first tube of imperial size to create a connection with a second tube of metric size allows to reduce the number of fittings which has to be provided on metric and imperial size tubing systems.
Preferably, the fitting adapted to receive a first tube of imperial size can be deformed with a press tool adapted to be placed on the fitting adapted to receive the first tube of imperial size and the press tool is used to press the fitting on a second tube of metric size inserted in the fitting at the place of the first tube of imperial size.
Preferably, the press tool can be used to obtain a final diameter Df of the press position of the press tool for a second tube of metric size inserted in the fitting which is smaller than for a first tube of imperial size inserted in the fitting.
Preferably, the press tool is used having an exchangeable insert to provide multiple inserts with different final diameters Df in the press position C.
In the drawings the aspects of the invention are explained in detail showing different embodiments. It is shown in:
In
In general, the first and the second tube to be connected with the two ends of the fitting 1 are of the same dimensions.
To explain the invention, another terminology is used for the first tube and the second tube: there is on one hand a combination of the fitting connected to a first type of (first) tubes and on the other hand a further combination of the fitting connected to a second type of (second) tubes, the second type of tubes being of a different size than the first type of tubes. So, in the following, the second tube is not the tube placed in the second end of the fitting, but a tube of the second type of tubes.
Although it is possible to use the same fitting with a tube of the first type and with a tube of the second type, such tubing systems are not yet common in practice.
The fitting 1 has a first outer diameter R11 at the first fitting end 1.1 and a second outer fitting diameter R21 at the second fitting end 1.2. The first outer diameter R11 of the first fitting end 1.1 is the same or substantially the same as the second outer diameter R21 of the second fitting end 1.2.
The first fitting end 1.1 and the second fitting end 1.2 have each a radial deformation zone 3, 3′ to fix the fitting 1 at the first tube 2 and at the second tube 2′ by use of a press tool, described later. The deformation zone 3, 3′ is at least on one side of a sealing element 4, 4′, but can also extend over the sealing element 4, 4′ and further parts of the fitting ends 1.1, 1.2. on the inner side in relation to the sealing element 4, 4′, as is shown later in
In
In
The hook element with the diameter R15, the sealing element 4 and the part extending from the sealing element 4 inwardly with the diameter R12 are in close contact with the surface of the first tube 2.
As can be seen in
As can be easily understood, the press tool has to be brought in a more narrow end position as in
On the right side of
Again, it is pointed out that the in the common practice of tubing systems there is no combination of imperial size tubes with metric size tubes, although the fitting of the invention would allow such a combination in certain cases.
On the right side of
Since the fitting 1 is intended to be used with the first tube 2 and/or with the second tube 2′, the first outer fitting diameter R11 is the same as the second outer fitting diameter R21 and the same for the inner fitting diameter R12 and R22. The difference between the first reduced fitting diameter R11′ and the second reduced inner fitting diameter R22′ is related to the difference of the first tube end diameter R13 and the second tube end diameter R23. In general, the difference between the first reduced fitting diameter R11′ and the second reduced inner fitting diameter R22′ is equal to the difference of the first tube end diameter R13 and the second tube end diameter R23, which leads to a bigger change of the second reduced fitting end diameter compared to the second fitting diameter than the change of the first reduced fitting end diameter compared to the first fitting diameter.
Although the fitting end 1.1, 1.2 experiences more deformation connecting the fitting 1 to the second tube 2′ than connecting the fitting 1 to the first tube 2, the amount of the deformation is still not more to maintain that the mechanical connection is sufficiently strong.
Other than shown in
It is worth to note that each tube diameter corresponds with a special press geometry of the press jaw to allow placing the press tool on the fitting and to press the fitting on the tube until reaching a final press position C, see
The process of creating a press connection between a fitting and a tube as described in the
To provide a tubing system, at least a first tube having a first tube end of a first outer diameter is connected to at least one fitting with a first fitting end of a first inner diameter to receive the first tube. The fitting has a second fitting end of a second inner diameter, the first inner diameter of the first fitting end to receive the first tube end is substantially the same as the second inner diameter of the second fitting end which is able to receive the first tube. F
The first fitting end and the second fitting end have a radial deformation zone to fix the fitting and the tube together forming after the deformation of the deformation zone a connection between them.
Following the invention, it is not the first tube which is used to provide the tubing system, but it is a second tube with a second tube end which is connected to the first fitting end and to the second fitting end. There is a difference between the first outer diameter of the first tube end and the second outer diameter of the second tube end. Thus, in a more practical definition, what is different in the invention is the fact, that the same fitting designed for a connection with an imperial size tube is used to be connected with a metric tube.
To obtain a secure connection, the press geometry of the press tool and the final end position of the press tool is different for pressing the fitting an a tube with imperial size and for pressing the same fitting on a smaller tube of metric size.
As an example, a standard fitting of ½″ imperial size, that is 12.7 mm, would be used with a standard tube of ½″ imperial size as in the state of the art, but the same fitting can be used with a metric size tube of 12 mm metric which is inserted in the fitting at the place of the imperial size tube. The difference between the ½″ imperial size and 12 mm metric size is 0.7 mm and the press tool has to press the imperial size fitting of ½″ on the metric tube of 12 mm with at least this supplemental distance of 0.7 mm compared to a press tool pressing the imperial size fitting of ½″ to an imperial size tube of ½″.
It should be understood that the diameters are the nominal diameters including the regular tolerances of production.
Number | Date | Country | Kind |
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10 2020 107 498.0 | Mar 2020 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/056690 | 3/16/2021 | WO |