CONNECTOR SYSTEM WITH RELEASABLE CONTOUR SEAL FOR A FLUID SYSTEM

Abstract

A connector system providing a releasable, liquid-tight seal for a fluid system is provided. The system includes a female connector, having a cylindrical opening, and a male connector, having a tubular end section, which is to be inserted in an insertion direction into the cylindrical opening. Inside the tubular end section, a fluid passage is formed. On an outer circumferential surface of the tubular end section, annular protrusions are integrally formed. When the tubular end section with the annular protrusions is inserted into the cylindrical opening, the intermediate protrusion and the rear protrusion each form a press-fit with the inner circumferential surface of the cylindrical opening, whereby a liquid-tight seal between the male connector and the female connector is generated.

Claims

1. A connector system providing a releasable, liquid-tight seal for a fluid system, the connector system comprising: a female connector, having a cylindrical opening along a longitudinal axis with an inner circumferential surface; and a male connector, having a tubular end section along the longitudinal axis, which is to be inserted in an insertion direction into the cylindrical opening, wherein inside the tubular end section a fluid passage is formed along the longitudinal axis, and wherein on an outer circumferential surface of the tubular end section, annular protrusions (B, C) are integrally formed, the annular protrusions (B, C) comprising: an intermediate protrusion (B) having an outer diameter (Rb), which is bigger than an inner diameter (D) of the cylindrical opening, and a rear protrusion (C) located with respect to the insertion direction behind the intermediate protrusion (B) having an outer diameter (Rc), which is bigger than the outer diameter (Rb) of the intermediate protrusion (B); wherein, when the tubular end section with the annular protrusions (B, C) is inserted into the cylindrical opening, the intermediate protrusion (B) and the rear protrusion (C) each form a press-fit with the inner circumferential surface of the cylindrical opening, whereby a liquid-tight seal between the male connector and the female connector is generated.

2. The connector system according to claim 1, wherein the annular protrusions further comprise: an annular front protrusion (A) located with respect to the insertion direction in front of the intermediate protrusion (B), which has an outer diameter (Ra), which is the same or smaller as the inner diameter (D) of the cylindrical opening.

3. The connector system according to claim 1, wherein: the outer diameters (Ra, Rb, Rc) of the protrusions (A, B, C) are defined by the outermost points in radial direction on the circumferential outer surfaces of each protrusion (A, B, C); and the outer diameters (Ra, Rb, Rc) of the protrusions (A, B, C) define a conical surface around the longitudinal axis.

4. The connector system according to claim 3, wherein: the conical surface has an inclination angle relative to the longitudinal axis in the range of 0.5 to 1 degree.

5. The connector system according to claim 1, wherein: a contour of a protrusion (A, B, C) is defined by the shape of its outer surface along the longitudinal axis; and the region of the contour of a protrusion (A, B, C), which is in contact with the female connector in a press-fit, has the same convex shape in insertion and extraction direction along the longitudinal axis.

6. The connector system according to claim 1, wherein: the protrusions (A, B, C) are rotationally symmetrical with regard to the longitudinal axis; and the protrusions (A, B, C) have the same contour arranged in different radial distances from the longitudinal axis.

7. The connector system according to claim 1, wherein: the protrusions (A, B, C) have a circular contour with the same radius.

8. The connector system according to claim 1, wherein: the female connector further forms a fluid passage along the longitudinal axis adjacent to the cylindrical opening, wherein the fluid passages of the female and male connectors have the same cross section; and an end surface of the tubular end section of the male connector abuts an end surface of the fluid passage of the female connector in longitudinal direction, such that the fluid passages of the female and male connectors, are seamlessly merged.

9. The connector system according to claim 1, wherein: one of the female or the male connector further comprises a union thread on its outer circumferential surface; the other one of the female or the male connector, comprises an annular union protrusion; and the connector system further comprises a union nut mechanically engaging the union protrusion and the union thread, wherein the female and the male connectors, are held in an inserted state.

10. The connector system according to claim 1, wherein the male connector is made of a single material.

11. The connector system according to claim 10, wherein the female connector is made of a single material, which is more elastic than the material of the male connector.

12. The connector system according to claim 1, wherein the male and the female connectors are monolithic plastic injection-moulded parts.

13. The connector system according to claim 1, wherein the female and male connectors are configured to be connected in a linear movement, without rotational movement, along the longitudinal axis to generate a liquid-tight seal.

14. The connector system according to claim 1, wherein no additional sealing component, specifically elastomeric component, is used in the connection system to generate the liquid-tight seal.

15. The connector system according to claim 1, wherein between the intermediate protrusion (B), the rear protrusion (C), and the inner circumferential surface of the cylindrical opening, a closed labyrinth is generated.

16. A coupling system for a hose, the coupling system comprising: a connector having a cylindrical wall defining an inner fluid passage along a longitudinal axis; wherein the connector has an outer circumferential surface defining an outer thread, and a conical section, which is integrally formed in the cylindrical wall and whose diameter is reduced towards an end face of the connector, and which is to be inserted into a hose; and a tubular clamping nut arranged around the connector along the longitudinal axis; wherein the clamping nut has an inner circumferential surface defining an inner thread engaging the outer thread of the connector, wherein rotation of the threads causes the clamping nut to move relative to the connector along the longitudinal axis; wherein the inner circumferential surface of the clamp further defines a clamping surface around the conical section of the connector; and wherein by rotation of the clamp around the connector, a clamping distance (P) between the clamping surface and a lateral surface of the integrally formed conical section is reduced, in order to press a hose wall against the conical surface.

17. The coupling system according to claim 16, wherein: the clamping surface extends rotationally symmetrically along the conical section, and during rotation the lateral surface of the conical section and the clamping surfaces are shifted along the longitudinal axis towards each other.

18. The coupling system according to claim 17, wherein: the clamping surface and the conical surface are parallel surfaces and, during rotation of the clamp, are shifted in parallel to each other.

19. An automatic analyzer comprising: a connector system providing a releasable, liquid-tight seal for a fluid system, the connector system comprising: a female connector, having a cylindrical opening along a longitudinal axis with an inner circumferential surface; and a male connector, having a tubular end section along the longitudinal axis, which is to be inserted in an insertion direction into the cylindrical opening, wherein inside the tubular end section a fluid passage is formed along the longitudinal axis, and wherein on an outer circumferential surface of the tubular end section, annular protrusions (B, C) are integrally formed, the annular protrusions (B, C) comprising: an intermediate protrusion (B) having an outer diameter (Rb), which is bigger than an inner diameter (D) of the cylindrical opening, and a rear protrusion (C) located with respect to the insertion direction behind the intermediate protrusion (B) having an outer diameter (Rc), which is bigger than the outer diameter (Rb) of the intermediate protrusion (B); wherein, when the tubular end section with the annular protrusions (B, C) is inserted into the cylindrical opening, the intermediate protrusion (B) and the rear protrusion (C) each form a press-fit with the inner circumferential surface of the cylindrical opening, whereby a liquid-tight seal between the male connector and the female connector is generated.

20. The automatic analyzer as claimed in claim 19, wherein the automatic analyzer further comprises at least one receiving position for a liquid vessel.

21. The automatic analyzer as claimed in claim 19, further comprising at least one robotically displaceable transfer arm.

22. An automatic analyzer comprising: a coupling system for a hose, the coupling system comprising: a connector having a cylindrical wall defining an inner fluid passage along a longitudinal axis; wherein the connector has an outer circumferential surface defining an outer thread, and a conical section, which is integrally formed in the cylindrical wall and whose diameter is reduced towards an end face of the connector, and which is to be inserted into a hose; and a tubular clamping nut arranged around the connector along the longitudinal axis; wherein the clamping nut has an inner circumferential surface defining an inner thread engaging the outer thread of the connector, wherein rotation of the threads causes the clamping nut to move relative to the connector along the longitudinal axis; wherein the inner circumferential surface of the clamp further defines a clamping surface around the conical section of the connector; and wherein by rotation of the clamp around the connector, a clamping distance (P) between the clamping surface and a lateral surface of the integrally formed conical section is reduced, in order to press a hose wall against the conical surface.

23. The automatic analyzer as claimed in claim 22, wherein the automatic analyzer further comprises at least one receiving position for a liquid vessel.

24. The automatic analyzer as claimed in claim 22, further comprising at least one robotically displaceable transfer arm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In the following, concepts in accordance with exemplary embodiments of the invention will be explained in more detail with reference to the following drawings, in which like reference numerals refer to like elements.

[0082] FIG. 1 schematically illustrates a connector system in a liquid system, according to embodiments of the invention.

[0083] FIG. 2 schematically illustrates the piercing needle inserted into the manifold of FIG. 1, according to embodiments of the invention.

[0084] FIG. 3 schematically illustrates the piercing needle of FIGS. 1 and 2, according to embodiments of the invention.

[0085] FIG. 4 schematically illustrates a connector system, according to embodiments of the invention.

[0086] FIG. 5 schematically illustrates the connector system of FIG. 4 with two tubular clamping nuts, according to embodiments of the invention.

[0087] FIG. 6 schematically illustrates a cross-section of a connector system, according to embodiments of the invention.

[0088] FIG. 7 schematically illustrates the connector system of FIG. 6 with a union nut.

[0089] FIG. 8 schematically illustrates a coupling system with a hose, according to embodiments of the invention.

[0090] FIG. 9 schematically illustrates a tubular end section of a male connector, according to embodiments of the invention.

[0091] FIG. 10 schematically illustrates an inclination angle of protrusions, according to embodiments of the invention.

[0092] FIG. 11 schematically illustrates the tubular end section of FIG. 9 inserted into a cylindrical opening of a female connector.

DETAILED DESCRIPTION

[0093] The above and other elements, features, steps, and concepts of the present disclosure will be more apparent from the following detailed description in accordance with exemplary embodiments of the invention, which will be explained with reference to the accompanying drawings.

[0094] It is to be understood that the following description of embodiments is not to be taken in a limiting sense. The scope of the invention is not intended to be limited by the embodiments described hereinafter or by the drawings, which are taken to be illustrative only. The features of the various examples may be combined with each other, unless specifically noted otherwise.

[0095] The drawings are to be regarded as being schematic representations, and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose become apparent to a person skilled in the art. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein may also be implemented by an indirect connection or coupling.

[0096] In conventional connector systems, a piercing needle is sealed with an elastic seal. Depending on the fluid used, a different elastic seal is used, which needs to be of a higher quality the more aggressive the fluid. The elastic seal is located on the outer diameter of the piercing needle. The piercing needle is screwed into the interface in order to obtain pressing of the seal. Depending on hardness and material, an appropriate torque is applied.

[0097] In other conventional techniques, SMC fittings are sealed with an elastic seal from the outside onto the outer diameter of the hose. CPC fittings provide sealing with an elastic seal in the fitting itself. Fittings by Diba Industries, IDEX Health & Science LLC, or The Lee Company provide e.g. sealing via a flanged hose flat on the interface. These are then pressed from behind by a hollow screw. Depending on hardness and material, an appropriate torque is applied.

[0098] Using elastomeric annular parts, such as O-rings etc., for generating and maintaining the sealing, conventional connector systems are dependent of the media flowing through, wherein the material of an elastomer is to be chosen to be resistant to the liquid media.

[0099] In the following, various mechanisms with respect to leakage-free sealing with releasable connections (e.g. for a piercing needle or a fitting) in fluid systems will be described.

[0100] The disclosed techniques do not require any elastomeric shaped part (O-ring, etc.) for generating and maintaining the sealing. The device is independent of and resistant to the media flowing through, wherein the fluid material and a material of an elastomer are not to be chosen to be compatible with each other.

[0101] FIG. 1 schematically illustrates a connector system 100 in a liquid system, according to embodiments of the invention.

[0102] As can be seen in FIG. 1, a piercing needle 101 is used to penetrate a septum 102 on a storage bottle 103. The piercing needle 101 is placed in a manifold 104. Through the piercing needle 101, the cleaning liquid from the storage bottle 103 is introduced via the manifold 104 into the liquid system of an analyzer.

[0103] In the example of FIG. 1, the piercing needle 101 may correspond to a male connector, wherein the manifold 104 may correspond to a female connector. A liquid tight seal is provided between the piercing needle 101 and the manifold 104.

[0104] FIG. 2 schematically illustrates the piercing needle 101 inserted into the manifold of FIG. 1 in more detail, according to embodiments of the invention.

[0105] As can be seen in FIG. 2, the piercing needle 101 is composed of the hollow needle 105 and a fitting 106, which may correspond to a male connector 20 according to the present disclosure. The hollow needle 105 is pressed in the fitting 106. The fitting 106 has an inner fluid passage 23 defined along a longitudinal axis 1.

[0106] The manifold 104 has a cylindrical opening 11, wherein a tubular end section with a sealing contour 5 of the fitting 106 is inserted.

[0107] As can be further seen in FIG. 2, the manifold comprises a threaded cylindrical opening with a diameter bigger than the cylindrical opening 11 and directly adjacent to the cylindrical opening 11, in which a threaded section of the fitting 116 is situated in threaded engagement with the manifold 104. The fitting 106 is screwed into the manifold 104 and held in place by the threads.

[0108] The sealing contour 5 of the fitting 106 is located in the outer circumferential surface of the fitting 106 inserted into the cylindrical opening 11 and a press-fit providing a liquid-tight sealing.

[0109] FIG. 3 schematically illustrates the piercing needle 101 of FIGS. 1 and 2, according to embodiments of the invention.

[0110] As depicted in FIG. 3, the piercing needle 101 comprises the hollow needle 105, which is pressed into a fitting part 106.

[0111] The fitting 106 corresponds to a male connector 20 according to the present disclosure. The fitting 106 comprises a tubular end section 21 with a sealing contour 5, and a threaded section with an outer thread 107. The outer thread 107 may be used to screw the piercing needle into a manifold, which may correspond to a female connector according to the present disclosure.

[0112] Inside the fitting 106, the hollow needle 105 and a fluid passage 23 are aligned with the longitudinal axis 1. The fluid passage 23 is formed by an inner circumferential surface 22 of the tubular end section 21.

[0113] FIG. 4 schematically illustrates a connector system 100, according to embodiments of the invention.

[0114] The connector system 100 comprises a female connector 10 and a male connector 20, which are held together by a union nut 109. On an outside end, which is the other end of each of the female and male connectors along the longitudinal axis from the end, where the liquid-tight seal is generated, a coupling system for coupling a hose to each of the female and male connectors, according to the present disclosure is defined.

[0115] For coupling system into a hose, an outer thread 25 and a conical section 26 are formed on each of the outer ends, which will be described in more detail with reference to FIG. 8.

[0116] FIG. 5 schematically illustrates the connector system of FIG. 4 with two tubular clamping nuts 30, according to embodiments of the invention. The tubular clamping nuts 30 will be described in more detail with reference to FIG. 8.

[0117] As can be seen in FIGS. 4 and 5, the fitting pair, i.e. the connector system, is composed of a fitting with the sealing contour 5 and of a fitting with the cylindrical bore 11. To produce a connection between both of them, they are screwed together with a union nut 109.

[0118] FIG. 6 schematically illustrates a cross-section of a connector system 100, according to embodiments of the invention.

[0119] The connector system 100 comprises a male connector 20, which is pressed into a female connector 10 in insertion direction 2.

[0120] Each of the male connector 20 and the female connector 10 are aligned along the longitudinal axis 1 and may further have a coupling end to be coupled to a hose.

[0121] Each of the coupling ends define a conical section 26 to be inserted into a hose and an outer thread 25 on which a tubular clamping nut for clamping the hose may be arranged.

[0122] The male connector 20 further comprises a tubular end section 21, which is inserted into a cylindrical opening 11 of the female connector 10 having an inner diameter D.

[0123] The tubular end section 21 has an outer circumferential surface 24, on which a sealing contour 5 is formed. In an inserted state, sealing contour 5 defines 3 annular protrusions in press-fit contact with the inner circumferential surface of the cylindrical opening 11.

[0124] On an outside surface of the female connector 10, in a radial direction over the tubular end section 21, the female connector 10 has an outer thread 27 defined, which is a thread for engagement with a union nut to hold the female and male connectors together.

[0125] FIG. 7 schematically illustrates the connector system of FIG. 6 with a union nut 109.

[0126] As can be seen in FIG. 7, the union nut 109 causes a linear pressing of the male connector 20 with the sealing contour 5 and of the female connector 10 with the cylindrical bore 11, without the female and male connectors having to be rotated.

[0127] Union nut 109 comprises an inner thread 110 in engagement with the outer thread 27 of the female connector 10. The union nut one hundred and 9 further engages in union protrusion 111, in order to hold the male connector 20 in place.

[0128] As depicted in FIG. 7, a continuous inner fluid passage is formed by the fluid passage 23 of the male connector 20 and the fluid passage 13 of the female connector 10. At the end of the cylindrical opening 11, the fluid passage 23 of the female connector having a smaller diameter is joined to the cylindrical opening 11 in a step, or in other words by shoulder or end surface 14 of the female connector 10. Onto this end surface 14, an end surface 28 of the tubular end section 21, which is the end face of the tubular end section 21 in insertion direction 2, abuts, wherein the in the fluid passages are seamlessly merged, without forming an undercut or a groove. In this regard, the front protrusion may mechanically support the tubular wall section, if it has the same outer diameter as the inner diameter of the cylindrical opening 11.

[0129] FIG. 8 schematically illustrates a coupling system with a hose, according to embodiments of the invention.

[0130] As illustrated in FIG. 8, a hose 112 may be engaged elastically over a conical section 26, which is a one-step conical shoulder, of a female or male connector until it reaches a stop surface, i.e. is fully inserted. A release of the hose 112 is prevented with a tubular clamping nut 30.

[0131] A conical section is integrally formed in a cylindrical wall of a connector 20. In particular, the conical section 26 comprises a conical lateral surface, which is angled towards the end face of the connector 20 and in an arrow or hook shape, and which is inserted into the hose 112.

[0132] The tubular clamping nut 30 comprises on an inner circumferential surface 31 an inner thread 35 engaging the outer thread 25 of the connector. The inner circumferential surface 31 further forms a clamping surface 32, which extends around the lateral surface of the integrally formed conical section 26.

[0133] When the clamping nut 30 is rotated around the connector 20, it is linearly shifted along the longitudinal axis 1, whereby the distance P between the lateral surface of the conical section 26 and the clamping surface 32 is reduced. In this example, the lateral surface of the conical section 26 and the clamping surface 32 are parallel surfaces, which are shifted in parallel with regard to each other, when the clamping nut 30 is rotated. Thereby, the hose 112 may be fixed between the one-step conical shoulder and the clamping nut 30, wherein the hose wall may be pressed against the conical section 26 without being shifted further along the conical section 26.

[0134] In particular, this coupling system may be comprised of the female 10 and/or the male connector 20, according to the present disclosure, on to a plane and side, which is situated opposite of the tubular end section 21 and/or the cylindrical opening 11.

[0135] FIG. 9 schematically illustrates a tubular end section 21 of a male connector 20, according to embodiments of the invention.

[0136] As can be seen in FIG. 9, the sealing contour 5 consists of three protrusions A, B, C, which may be referred to as annular sealing protrusions, and which are circumferential rings extending over a circumferential base surface of the tubular end section 21, around the longitudinal axis, and integrally formed within the tubular section 21 of the same material as the whole male connector 20.

[0137] The front protrusion A extends over an outer diameter of 4 mm of the end face of the tubular end section 21 and is located on a front side with respect to insertion direction 2.

[0138] The intermediate protrusion B extends in a radial direction over the front protrusion A, and is situated directly adjacent to front protrusion A, wherein in the contour 5, the convex contours 113 of protrusions A and B are connected by a concave contour region 115.

[0139] The intermediate protrusion C extends in a radial direction over the intermediate protrusion B, and is situated directly adjacent to intermediate protrusion B, wherein in the contour 5, the convex contours 113 of protrusions B and C are connected by a concave contour region 115, which is the same as between protrusions A and B.

[0140] These protrusions all have the same profile, i.e. the same convex profile 113 and the same concave profile 115, and also the same distance between the rings A, B and rings B, C. However, the different sealing protrusions are arranged in different radial distances from the longitudinal axis, such that a force for introducing the tubular end section 21 into the cylindrical opening 11 is regularly increased along the longitudinal axis 1. In other words, there may be no other convex sections in the sealing profile between the convex sections of the sealing protrusions A, B, C.

[0141] The ring A with an outer diameter Ra of 5.1 mm serves for centering in the cylindrical bore 11 of the female connector 10. The cylindrical bore 11 has an inner diameter D of 5.1 mm.

[0142] The ring B has an outer diameter Rb of OD 5.2 mm, and the ring C an outer diameter Rc of 5.3 mm. The two rings B and C form a press-fit with the inner circumferential surface of the cylindrical opening 11, wherein the inner circumferential surface is deformed elastically, to create a closed labyrinth.

[0143] The pressing depths in press fits of rings B and C thereby amounts to 0.05 mm at ring B, and 0.1 mm at ring C.

[0144] As can be seen in FIG. 9, the distances along the longitudinal axis 1 of the centers of the circular contours of the rings A and C are spaced equally from the center of the circular contour of ring B.

[0145] When regarding the convex contours of one of rings A, B, and C, it is to be noted that with regard to a symmetry axis 6, which extends through the vertex of the protrusion, the contour is symmetrically shaped to both sides, i.e. in insertion direction 2 and the opposite direction, which is the extraction direction. In other words, by using a circular convex contour for each of rings A, B, C, and/or a circular concave contour to connect the convex contours, the contour seal created to the female connector may easily be moved along the longitudinal axis, specifically may easily be released.

[0146] By means of these respective press-fits, the system is sealed in a liquid-tight and air-tight manner, wherein possible adhesion of the liquids is thereby suppressed.

[0147] FIG. 10 schematically illustrates an inclination angle of protrusions, according to embodiments of the invention.

[0148] In FIG. 10, an upper half of the tubular end section 21 is depicted, wherein the outer diameters of rings A, B, C are exaggerated and not to scale, in order to show the inclination angle defined by rings A, B, C.

[0149] As can be seen in FIG. 10, the outer diameters of rings A, B, C define a conical surface 3, which is angled towards the longitudinal axis 1 through the center of the male connector and the female connector. The angle 4 between the conical surface 3 and the longitudinal axis 1 may be characteristic for a pressing ratio of the connector system 100.

[0150] FIG. 11 schematically illustrates the tubular end section 21 of FIG. 9 inserted into a cylindrical opening 11 of a female connector 10.

[0151] As can be seen in FIG. 11, in the connector system 100, a press-fit seal 8 is formed between female and male connectors 10, 20 at the outer diameter Rc of protrusion, or ring, C. A further press-fit seal 8 is formed at outer diameter Rb of ring B, wherein ring A does not form a press fit and contacts the inner surface of the cylindrical opening 11 having a diameter of D.

[0152] From the above said, the following general conclusions may be drawn.

[0153] In various examples, the fluid passages of the female and male connectors are cylindrical with the same diameter, wherein the inner passages are merged at the end surfaces of the male and female connectors, which may be perpendicular end surfaces with respect to the longitudinal axis, to form a continuous cylindrical inner passage for the fluid.

[0154] In general, by the disclosed techniques a releasable seal may be provided, wherein the connected male and female connectors may be disconnected, in other words removed or disassembled, from each other, and wherein any elastic deformations are removed, wherein the female and male parts are restored into their original dimensions, i.e. no plastic deformation may be applied to the connectors while providing a liquid-tight, i.e. fluid-tight, seal.

[0155] In general, the contact points between the protrusions and the inner surface of the female connector cylindrical opening, may lie on a cone, in other words may define a conical surface, wherein such a cone over the contact points may define a pressing ratio. A pressing ratio may be adjusted based on the materials used in the connectors, and/or the maximum fluid pressure in the fluid system, and/or the mechanical stress on the coupling, or connector, system.

[0156] The three protrusions may be referred to a contour of the male connector, specifically the outer surface of the tubular end section. Respectively, the seal provided by the protrusions may be referred to as a contour seal, specifically a releasable contour seal.

[0157] A distance between the centers of the protrusions, along the longitudinal axis, may be defined using the outer diameters of the protrusions, and/or the radial distances of the protrusions, and/or the contours of the protrusions. In particular, when circular contours are used for the protrusions, the distance between the centers of the circular contours in longitudinal direction may be in the range of a factor 1.5 to 2 of the radius of the circular contours.

[0158] An arrangement along the longitudinal axis may be refer to as an alignment with the longitudinal axis, such that an axis of a respective part lies on the longitudinal axis.

[0159] In various examples, the three contours may be circular contours with the same radius, wherein the center of the circles are shifted in the radial direction by steps of 0.1 of the radius.

[0160] In various examples, the contours of the protrusions have a round shape, and/or a circular, and/or a symmetrical shape with regard to both the insertion and extraction direction, has the advantage that the connection and thereby, the liquid-tight seal may be easily disconnected. In this regard, the male connector may provide a nozzle to be inserted into e.g. a tube or a pipe, wherein the insertion force is equal to the extraction force, in contrast to known coupling nozzles, which have hook-shaped, or arrow-shaped protrusions.

[0161] In various examples, the parts of the contours, which are in contact during a press-fit may have a convex shape as explained above, wherein the rest of the contour may be concave, specifically the protrusions may be formed according to injection moulding design rules, in particular such that the connectors may be suitable for forced demoulding, wherein plastic parts of a tough, elastic material are deformed in the elastic range during ejection. The contours may be adapted based on the specific materials used for the female and male connectors, such that according to the present concept an elastic deformation is effected during sealing, i.e. the press-fit, when the connectors are assembled.

[0162] In various examples, both the female and male connectors may be made of a hard, or solid, or rigid material, in particular a plastic material, such as Polyetheretherketon (PEEK), in contrast to elastomers and metallic materials.

[0163] In various examples, the first protrusion may be in loose or interrupted contact during insertion for centering the male connector in the female connector, or may only be in sliding contact, not deforming the cylindrical opening, with in the inner surface of the cylindrical opening, whereby the first protrusion will not contribute to the liquid-tight sealing between the connector parts, but may be used for aligning the connector parts, specifically along the longitudinal axis, before inserting the intermediate and rear protrusion into the cylindrical opening.

[0164] It is to be understood, that the material of the female connector may be softer than the material of the male connector, or vice versa.

[0165] In general, the female connector may form the cylindrical opening as a cylindrical cavity, for example, having an inner diameter, which is relevant for the dimensions of the male protrusions and tubular end section. Further, the cylindrical opening may be formed in a receiving section of the female connector having an outer surface extending around the cylindrical opening, in other words, around the cylindrical opening there may be a wall, with a thickness with respect to the inner and outer surface in radial direction, wherein, it is to be understood that only the inner the circumferential surface is elastically deformed by the press-fit, wherein an outer surface of the female connector, specifically outer surface directly over the cylindrical opening in the radial direction, has no elastic deformation. In other words, the in the contour of the female connector may be deformed, while the outer contour of the female connector is not deformed. For example, a wall thickness around the inner cylindrical opening along the complete surface, which may form an interference fit with the annular protrusions, have a thickness, allows an elastic deformation of the inner circumferential surface, but no deformation of the outer contour around the cylindrical opening. In this regard, the difference between the outer diameter of a protrusion and the inner diameter of the cylindrical diameter may define a pressing depth into the cylindrical opening, which may not exceed a factor 0.4, or 0.3, or 0.2, 0.1, or 0.05 multiplied by the wall thickness around the cylindrical opening. In various examples, the female connector may not be an elastic hose, or any hose made from an elastomeric material, for example rubber. In various examples, the interference fit may be formed in the elastomeric deformation range of a thermoplastic material used for the female and/or the male connector. Specifically, the elastomeric deformation in the female connector may have a young modulus which is smaller than the young modulus of the male connector, thus leading to an elastic deformation of the cylindrical opening.

[0166] In various examples, a baffle coupling, a claw coupling, or a bayonet coupling may be used to hold the female and male connectors together in an assembled state.

[0167] The distances between the center points of the contours of the first, intermediate, and rear protrusions, and the radial distances of the center points may be chosen, such that a conical surface with a predefined, material- and use-specific inclination angle may be achieved.

[0168] In various examples, in longitudinal direction, there may be no abutment surfaces between the male connector and the female connector necessary.

[0169] The connector system may also be referred to as fitting system in a fluid system. The male connector may specifically be connected with a piercing needle and may thus provide a releasable contour seal on the piercing needle.

[0170] Summarizing, a connector system is provided, which generates a liquid-tight seal by two press-fits between annular rings of a male connector and a cylindrical opening wall of a female connector. A second press-fit has a stronger pressing dimension into the wall of the cylindrical opening, than a first press fit. A first annular ring may be used for centering of the male connector in the cylindrical opening. In preferred examples, each annular ring in a press fit has the same contour in both insertion and extraction direction, specifically a circular contour with different radial heights. The centering annular ring may have the same diameter as the cylindrical opening for precise centering and mechanical stability.

[0171] Thereby, as plastics injection-moulded parts, the requirements may be easily met. The seal may be both liquid-tight and airtight. The seal works in all common diameters in metric and inch as long as the press ratio is maintained. The seal may work independently of the material, as the outer material is only minimally deformed in the elastic range. The shape of the seal may be independent of the liquids used and the length of the exposure time. The seal may not require a stop in the insertion direction, as for example when pressing an O-ring. No tools or a defined torque are required for pre-assembly and assembly of the fitting system.

[0172] Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to those skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications and is limited only by the scope of the appended claims.