Connector for fluid chromatography

The invention generally relates to a connector for fluid chromatography, such as gas chromatography and liquid chromatography, having a female assembly including a receiving member being designed and configured to receive, and releasably interlock with, a male assembly. The connector is particularly suited for high performance liquid chromatography (HPLC) applications.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates generally to connectors for fluid chromatography, such as gas chromatography (GC) and liquid chromatography (LC), particularly for the high performance regime, such as high pressure liquid chromatography—HPLC.

Description of the Related Art

Various design solutions for fluid connectors in general exist in the state of the art, a selection thereof being summarized in the following.

The international patent application WO 2013/174421 A1 discloses a sealing element for sealing a fluidic connection between a coupling element and a tubular element and is stated to thereby provide a sealed flow path through the tubular element and between the coupling element and the tubular element in a longitudinal direction. The sealing element is stated to comprise a recess extending in the longitudinal direction, wherein the recess is adapted for receiving the tubular element, and a transverse wall defining an extent of the recess in the longitudinal direction, wherein the transverse wall has a through hole.

The international patent application WO 2012/116753 A1 discloses a sealing fluidic component which is stated to comprise a capillary enclosing a fluid conduit and having an exterior surface being at least partially coated with a coating of a meltable material. Further comprised is a sealing at an end portion of the capillary integral with the coating, constituted at least partially by the meltable material, and formed by melting the meltable material of the coating at the end portion and re-solidifying the melted material.

U.S. patent application 2006/0239863 A1 to Zach et al. discloses a line element for handling fluids that is stated to comprise at least one temperature-resistant and pressure-resistant support element having a first interior in which an inner line made of a plastic material resistant to chemicals is arranged. At least one free end of the line element is stated as being provided with a connector element having a second interior into which the inner line extends. The support element or the connector element is stated to have at least one relief opening which ensures a communicating link between the first interior of the support element or the second interior of the connector element and the environment.

U.S. Pat. No. 6,575,501 B1 to Loy Jr. et al. discloses a deformable bushing to seal tubing to a receiving body.

U.S. Pat. No. 9,091,693 B2 to Hochgraeber et al. discloses a plug unit to be connected to a complementary bushing unit for chromatography applications. Essential for the disclosed technical teaching is a pressure piece that is crimped locally into a capillary tube assembly having a sealing element. In order to achieve the sealing between plug unit and bushing unit, pressurization forces are stated to be transmitted from the plug housing via the pressure piece toward the sealing element.

In view of the above, there is still a need for improvement with connectors for fluid chromatography, such as gas chromatography and liquid chromatography.

SUMMARY OF THE INVENTION

The invention relates generally to a connector for fluid chromatography. The connector has a female assembly with a receiving member being designed and configured to receive, and releasably interlock with, a male assembly. The male assembly comprises a force-transmitting member for exerting axial pressurization, further a capillary conduit reaching slidably through a passage in the force-transmitting member for transmitting chromatography fluid, yet further a sealing gasket surrounding a front end of the capillary conduit, the sealing gasket having a rearward facing surface located such as to directly contact a forward facing surface of the force-transmitting member for being subjected to axial pressurization thereby, and a jacket surrounding the sealing gasket for providing axial guidance and alignment thereto.

The force-transmitting member pressing against the sealing gasket directly, upon engaging the male assembly with the female assembly, without the aid of any additional force conveying means has the benefit that the axial forces employed for generating the seal are exerted in a very homogeneous manner about the circumference of the capillary conduit which strengthens and generally improves the sealing effect.

Preferred applications for such designs include nanoflow HPLC, using flow rates between about 1 to 1000 nanoliters per minute, and high flow HPLC, using flow rates of about one microliter per minute and above. Operating pressures may range from 5 to 300 bar and above, as may correlate to ultra performance LC (UPLC) and ultra high performance LC (UHPLC) where typical pressures can be in the range up to or even above 1000 bar.

In various embodiments, the force-transmitting member may comprise a stepped member having a first portion for exerting axial pressurization featuring a first outer diameter, and having a second axially adjacent portion featuring a second outer diameter being larger than the first outer diameter.

In various embodiments, the forward facing surface may be located at a front end of the first portion of the stepped member, the first portion being dimensioned such by axial length and diameter that it can be largely slidably received within a rear part of the jacket. The jacket's inner diameter can be in the lower millimeter range, such as between 0.5 and two millimeters, for example.

In various embodiments, a shape of the sealing gasket, the first portion of the stepped member and the jacket are preferably substantially annular cylindrical generally improving the ease-of-production of these elements of the male assembly.

In various embodiments, the connector may further comprise a third portion being located axially adjacent to the second portion of the stepped member for finger tightening a connection between the male and female assemblies, a third outer diameter of the third portion being larger than that of both the first and second portions. In order to render an improved haptic experience to an operator of the connector, an outer circumferential surface of the third portion can be textured, such as being provided with a knurl. The possibility to finger tighten the male assembly in the female assembly generally dispenses with the need for additional tools, such as wrenches, to establish the connection. In this manner the handling of the connector is simplified.

In various embodiments, axial lengths of the sealing gasket, the first portion of the stepped member and the surrounding jacket can be dimensioned such that a rearward-facing end of the jacket stays clear from a transition between the first portion and second portion of the stepped member.

In various embodiments, the connector may further comprise a constriction foreseen in the passage of the stepped member, wherein the capillary conduit has an outer coating layer (or additional protective tubing) at a position spaced apart from its front end, the coating layer (or protective tubing) being designed and configured to engage with the constriction and further having the function of a limit stop in order to limit axial movability of the stepped member relative to the capillary conduit. Moreover, this limit stop function helps avoid the male assembly becoming stuck in the female assembly, thereby facilitating its pulling out, and further prevents the capillary conduit from being pressed against the bottom of the one-sided port in a damagingly vigorous manner.

In certain embodiments, the first outer diameter of the first portion of the stepped member is preferably slightly undersized compared to that of the sealing gasket, so as to be slidably insertable into the jacket from behind. The magnitude of the undersize can be in the range of several hundred micrometers, such as 300 micrometers, for instance.

In various embodiments, a rearward facing front end of the sealing gasket that comprises the rearward facing surface stays free from being covered by the jacket and directly contacts a forward facing ground of a recess worked into the first portion of the stepped member with which the sealing gasket and jacket partly engage.

In various embodiments, the sealing gasket may stand out slightly from the front end of the capillary conduit in a disengaged condition of the male and female assemblies, and becomes compressed into a substantially flush alignment with the front end of the capillary conduit when the male and female assemblies are engaged with one another. Alternatively, it is also possible to arrange already for a flush alignment in the disengaged condition of the male and female assemblies. For certain embodiments, it might even be conceivable to arrange for the front end of the sealing gasket to be slightly retracted in the disengaged condition from a front end plane established by the capillary conduit and/or the co-extensive jacket. Upon pressurization from behind, the sealing gasket could then slightly bulge forward at the front end, thereby closing the gap to the front end plane and providing for a flush and tight seal.

In certain embodiments, a front end of the sealing gasket can be stepped such as to allow material deformation of the sealing gasket to occur substantially without any outward bulging, which generally may lead to a neater and more reliable sealing effect. A diameter reduction of the sealing gasket's front end, for example, entails pressurization force amplification at the interface where the seal is effected.

In various embodiments, a shape of the force-transmitting member can be substantially annular cylindrical, wherein an outer diameter of the force-transmitting member is slightly undersized compared to that of the sealing gasket in order that force transmission takes place only between the force-transmitting member and the sealing gasket without involving other elements of the connector.

In various embodiments, the receiving member can be one of a one-sided port and a double-sided union. In case of the one-sided port variant, it may have a doubly stepped circular recess, the inner diameter of the first recess step being adapted to the outer diameter of the jacket, and the inner diameter of the second recess step being larger than that of the first recess step. In certain embodiments, it can be adapted to a second outer diameter of a second portion of the stepped member, as described previously. In the case of the double-sided union variant, the aforementioned design features could just be mirrored and reproduced in an abutting (and opposing) relation as will become apparent from embodiments to be described further below.

In certain embodiments, a transition between the second recess step and the first recess step preferably has a conical shape, though it is also conceivable to design it with a perpendicular edge relative to the axis of the connector, for instance.

In some embodiments, both the second recess step and the second portion of the stepped member can have complementary interlocking mechanisms. One example of an interlocking mechanism would comprise an external thread foreseen at an outer circumferential surface of the second portion of the stepped member and a complementary internal thread foreseen at an inner circumferential surface of the second recess step. Other interlocking mechanisms are likewise conceivable, such as a bayonet fitting, for instance, and will be implemented by a skilled practitioner as is deemed fit.

In various embodiments, the one-sided port may have an axial through-bore located such that it comes to rest in opposing relation to the front end of the capillary conduit when the male and female assemblies are engaged with one another.

In various embodiments, the axial through-bore of the one-sided port can accommodate tubing that functions as a continuation of the capillary conduit when the male and female assemblies are engaged with one another. In the simplest example, the tubing is of the same design and configuration as the capillary conduit, such as fused silica capillary, in order to render a good geometric match of the two abutting front ends.

In various embodiments, the one-sided port may have a substantially flat bottom against which a front end of the male assembly is pressed when the male and female assemblies are engaged with one another. Such design ensures that the sealing is effected in the plane of the interface between the capillary conduit and any downstream tubing being coupled thereto, contrary to embodiments where the sealing is effected by means of two opposing frusto-conical surfaces of a complementary nut and ferrule assembly. The main advantage of such bottom seal over a ferrule seal is basically the lower dead volume.

In various embodiments, the sealing gasket may be jointed radially outward to the jacket as well as radially inward to the capillary conduit via opposing outward-facing and inward-facing surfaces, respectively. Preferably, the joint is, or the joints are, produced by one of adhesive, radial swaging, radial plastic deformation, hammering, and laser welding or any combination of these techniques. A skilled practitioner will understand that the heat necessary for welding can be generated by other means than just laser radiation. The joint serves to render the elements thusly jointed unmovable relative to one another even when exposed to external strain, such as axial pressurization of the sealing gasket by the first portion of the stepped member, for example.

In various embodiments, the connector may further comprise a hollow handling shell into which the force-transmitting member is partly accommodated thereby simplifying the manual handling of the connector. In certain embodiments, a second portion of the stepped member may be slidably accommodated in the hollow handling shell. In some cases, for example when a stepped member takes the shape of a T-shaped washer, it can be slidably accommodated fully within the hollow handling shell.

The hollow handling shell preferably comprises a first section with an interlocking mechanism designed and configured to cooperate with a complementary interlocking mechanism foreseen at the receiving member, such as the one-sided port or double-sided union, and further preferably comprises a second section for finger tightening the male assembly in the female assembly.

In certain embodiments, the hollow handling shell can further comprise an inward-protruding edge being designed and configured to engage with a second portion of the stepped member and further having the function of a limit stop in order to keep the stepped member from exiting the cavity of the hollow handling shell.

DETAILED DESCRIPTION

While the invention has been shown and described with reference to a number of different embodiments thereof, it will be recognized by those skilled in the art that various changes in form and detail may be made herein without departing from the scope of the invention as defined by the appended claims.

Fluid connectors are designed and configured to establish a fluid communication between an upstream device and a downstream device via intermediate fluid conduits. The upstream device may be a gas or liquid chromatograph or, more specifically, the associated chromatographic column that outputs an eluent of substances which have been separated chromatographically. The downstream device may be a mass spectrometer or, more specifically, the ion source thereof, such as an electrospray ion source. A skilled practitioner is familiar with such kind of instrumentation so that there is no need to elaborate thereon in further detail here. It is to be understood that a chromatography fluid will comprise a mobile phase, in the case of liquid chromatography usually made up of a suitable solvent, into which the sample to be analyzed has been spiked upstream of the chromatographic column.

FIG. 1Aschematically shows by way of example an upstream device2, such as a gas or liquid chromatograph, and a downstream device4, such as a mass spectrometer, which are both fluidly connected to one another by means of a conduit6. The conduit6may be flexible and coupled to the two devices2,4by virtue of fluid connectors8. Such connectors may be designed according to principles of the present invention to be expounded in the following.

FIG. 1Billustrates a connector8of slightly different design where a union receives two male assemblies, such as to be described further below, at two sides facing away from one another.

FIG. 2Ashows the different parts of a connector8in an exploded view. The basic components are the male assembly10and the female assembly12. The female assembly12comprises a one-sided port12* that basically may consist of a block of (synthetic or metallic) material into which two circular recesses14A,14B have been worked. The first circular recess14A has a flat bottom wall16including a through-bore18for accommodating a continuation fluid conduit (not shown here). The second circular recess14B has an internal thread20that is designed and configured to mate with an external thread foreseen at the stepped member as the force-transmitting member of the male assembly10to be discussed further below so as to facilitate a releasable interlocking function between the male and female assemblies10,12. A transition between the first and second circular recesses14A,14B tapers conically in the embodiment shown. It will, however, be appreciated by a skilled practitioner that the transition might also be designed in a different manner, such as substantially rectangular, for instance.

The male assembly10is comprised basically of four different elements. At the core of the male assembly10is a capillary conduit22, such as a capillary tube. An example of such conduit22would be a fused silica capillary, PEEKsil™ capillary or polyimide-clad fused silica capillary, a part of which is shown inFIG. 2A. Inner bore diameters may be in the range of several micrometers, such as ten or twenty micrometers reaching up to several hundreds of micrometers depending on the intended field of application. A sealing gasket24of substantially cylindrical shape is provided to be arranged on the front end of the capillary conduit22. The sealing gasket24may be made from any material that is deformable so that it is able, upon compression, to reliably seal two abutting surfaces, such as the flat bottom wall16of the first circular recess step in the one-sided port12* and the front end of the male assembly10. In preferred examples, the sealing gasket24is created in such a way as to prevent any material from coming into contact with the flow stream in the bore of the capillary conduit22which would run the risk of contaminating any working fluid therein. In the embodiment shown, the sealing gasket24has a stepped front end24* which provides for some space in the radial direction into which deformed gasket material may be accommodated upon compression, thereby preventing any outward bulging of the deformed gasket body that might hamper the sealing effect.

A lasting joint can be established between the capillary conduit22and the sealing gasket24by gluing them together via the radially outward and inward facing opposing circumferential surfaces, respectively. Other embodiments may employ laser welding where a part of the material at the radially opposing circumferential surfaces of the two elements to be jointed is exposed to electromagnetic radiation, such as laser light, so that it becomes partially molten and establishes an adhesive bond between the two contacting opposing surfaces upon re-hardening. Other ways of creating a joint are heating the complete body (or bodies) or just the surface(s) to be jointed and then fusing them together with the corresponding counterpart by heat, molding, infrared radiation etc.

Further provided is a stepped member26as the force-transmitting member having an internal passage28through which the capillary conduit22is bound to reach. In the embodiment shown, the passage28has basically two sections; a first section28A of narrow inner diameter dimensioned such as to closely but slidably accommodate the capillary conduit22and a second section28B of larger inner diameter. The transition28C between the first section28A and second section28B may comprise a perpendicular edge or, as illustrated, a slight conical taper. The edge at the transition28C in the passage28of the stepped member26may interact with a particular coating layer or additional protective tubing (not shown here) on parts of the capillary conduit22, thereby facilitating a limit stop that limits the axial movability of the stepped member26relative to the capillary conduit22which improves the handling of a connector thusly devised.

Viewed from outside, the stepped member26in the embodiment shown has three basic portions. The first portion26A is of smallest outer diameter being similar to that of the sealing gasket24, and generally takes the form of an annular cylindrical protrusion standing out from the rest of the stepped member26. The second portion26B of larger outer diameter features an external thread30at its outer circumferential surface that is bound to mate with the internal thread20at the second recess step14B in the one-sided port12* as described above. The third portion26C has the largest outer diameter and serves as the finger tightening portion at which an operator may screw the male assembly10into the female assembly12by turning. The dimensions of this third portion26C are preferably chosen such that easy manual handling by an operator is facilitated. An outer diameter of the third portion26C may be in the millimeter range, such as between six and seven millimeters, for example, but can generally be chosen by a skilled practitioner as is deemed fit.

The last element of the male assembly10is a jacket32that is generally of annular cylindrical shape and may be made of any rigid and dimensionally stable material, such as stainless steel, for example. The jacket32has an inner diameter adapted to closely accommodate the sealing gasket24. The jacket32and the sealing gasket24are jointed to one another via their radially inward and outward facing circumferential surfaces, respectively. One embodiment includes a swage joint between jacket32and sealing gasket24. Other embodiments may be of adhesive nature, or the like. It is to be noted that the dimensions of the jacket32and the first portion26A of the stepped member26are chosen in this example such that the jacket32may receive the first portion26A slidably, that is facilitating axial guidance and alignment but without substantially inhibiting any axial motion between the two. It is further to be noted that the axial lengths of the sealing gasket24, jacket32and first portion26A of the stepped member26are chosen such that, when the connection between the male and female assemblies10,12is established, the rearward facing front end of the jacket32stays clear from the transition between the first and second portion26A,26B of the stepped member26(shown as perpendicular in the instant example).

FIG. 2B(to the right ofFIG. 2A) shows the male assembly10put together and ready for being inserted into the one-sided port12* of the female assembly12. As can be seen, a short part of the front end of the sealing gasket24stands out from the front end of the capillary conduit22as well as from that of the co-extensive jacket32thereby rendering that part one which will contact the flat bottom wall16in the one-sided port12* first upon insertion of the male assembly10into the female assembly12, and will be deformed. A skilled practitioner will appreciate, however, that the sealing gasket24could be designed and arranged on the capillary conduit22such that its front end comes to lie substantially flush with the front end of the former. The sealing would then be effected as soon as the front ends of the three elements capillary conduit22, sealing gasket24and jacket32substantially simultaneously come into contact with the flat bottom wall16of the one-sided port12* upon insertion.

FIG. 2C(to the right ofFIG. 2B) shows the connection between the male and female assemblies10,12ofFIGS. 2A and 2Bwhen the internal and external threads20,30of the second recess step14B in the one-sided port12* and the second portion26B of the stepped member26have been engaged with one another. The first portion26A of the stepped member26as the force-transmitting member exerts axial compressing forces directly on the sealing gasket24that contacts the flat bottom wall16of the first recess step14A in the one-sided port12*, becomes deformed as a result and thereby seals this interface such that no fluid can escape the inner bore of the capillary conduit22radially but will rather flow forward into the adjacent connection tubing34foreseen in the through-bore18of the one-sided port12*. This design renders the pressurization forces being exerted very homogeneously about the circumference of the sealing gasket24and thereby allows for a very tight and reliable seal, suited for high pressure liquid chromatography applications often operating in a pressure range from about 50 to 350 bar or even higher, essentially without any significant dead-volume at the interface that could degrade performance, such as by sample carry-over.

A skilled practitioner will appreciate that one beneficial effect, among others, of the dimensionally stable jacket32surrounding the deformable sealing gasket24and comparatively delicate capillary conduit22is to prevent axial pressurization forces exerted on the sealing gasket24from being partially dissipated in radial outward directions which would weaken the pressure seal in the axially forward direction at the front end.

FIG. 3Adepicts another embodiment of a fluid connector8according to principles of the invention. As this additional embodiment shows a certain degree of similarity with that presented with reference toFIGS. 2A to 2C, the following description will focus on the differences there-between.

FIG. 3Aillustrates the different elements of a connector disassembled and placed next to one another. The one-sided port112* (rightmost) of the female assembly shows basically a block of (synthetic or metallic) material into which two circular recesses114A,114B have been worked, similar to the one shown inFIG. 2A. The jacket132(bottom center right) can be made of a dimensionally stable material, such as stainless steel, and comprises a basically annular cylindrical element dimensioned such as to accommodate the sealing gasket124(top center right) as well as the first portion126A of a stepped member126(top leftmost) as the force-transmitting member. The sealing gasket124is itself an annular cylindrical element in this example, without any stepped front end. In the embodiment shown, the front end of the sealing gasket124is bound to be arranged flush with that of both the capillary conduit122(center left) as well as that of the jacket132, as will be explained further below.

The connector comprises a capillary conduit122which in this example is further provided with a coating layer136(or additional protective tubing) that reaches up to a point spaced apart some distance from the front end of the capillary conduit122. The coating layer136allows for a bulkier design of upstream parts of the capillary conduit122and is intended to function as a limit stop when being inserted into the passage128in the stepped member126to be further discussed below. In so doing, the axial movability of the stepped member126in relation to the capillary conduit122can be limited, allowing for easier handling of the male assembly. It basically prevents certain individual elements of the assembly from accidentally falling apart.

The stepped member126in the instant embodiment has a first portion126A of substantially annular cylindrical shape that resembles that (26A) of the stepped member26described with reference to the embodiment inFIGS. 2A to 2C. The second portion126B of the stepped member126B, however, is in this example merely of annular cylindrical shape, too, without any additional features, such as an external thread (30) to enable an interlocking function. The passage128contained in the stepped member126has two distinct sections; one of small diameter that closely but slidably receives the capillary conduit122without coating layer136, whereas the other has a larger diameter dimensioned such as to slidably receive the capillary conduit122with the coating layer136. The transition128C between the two sections may interact with the coating layer136thereby limiting the axial movability as described above.

The most notable difference between the previous embodiment described with reference toFIGS. 2A to 2Cand the instant embodiment is the presence of an additional element, namely a hollow handling shell138(bottom leftmost). The hollow handling shell138comprises an internal passage140for closely but slidably accommodating the capillary conduit122with coating layer136which discharges into a cavity142of larger diameter that is dimensioned such as to slidably receive the second portion126B of the stepped member126. The cavity142may comprise an opening142* the inner diameter of which is constricted such as to provide for an inward-reaching edge144with which a front edge of the second portion126B of the stepped member126may engage in order to prevent it from accidentally falling out. The constriction can be brought about as shown by an annular cylindrical insert146put into the opening142* of the cavity142, for instance.

Viewed from outside, the hollow handling shell138has two distinct sections. The first section138A has an outer diameter that is adapted to substantially match the inner diameter of the second recess step114B of the one-sided port112*, and further comprises an external thread148which is configured to mate with the internal thread120foreseen at the second recess step114B of the one-sided port112* such as to allow for releasable interlocking between the male and female assemblies110,112of this embodiment.

The second section138B of the hollow handling shell138has a larger outer diameter and is designed and configured such as to be easily manually actuated so that it can serve as a finger tightening section. The outer circumferential surface of this second section138B may, for example, be textured in order to render a positive haptic feedback when being touched by an operator.

Thus, it can be seen that, during the putting together of the male assembly110, the second portion126B of the stepped member126is inserted into the cavity142of the hollow handling shell138and subsequently kept in place by the annular constriction cylinder146located at the opening142* of the cavity142. The capillary conduit122is inserted from behind into the passages140,128of both the hollow handling shell138as well as the stepped member126and reaches there-through so that it stands out from the front end of the first portion126A of the stepped member126. Then, the sealing gasket124may be arranged at the front end of the capillary conduit122and jointed thereto as has been indicated previously. The jacket132is finally put over the sealing gasket124and first portion126A of the stepped member126until its front end comes to lie substantially flush with those of the capillary conduit122and jacket132. As before, the jacket132is jointed rigidly merely to the underlying sealing gasket124but not to the first portion126A of the stepped member126which it merely slidably surrounds in the example shown thereby retaining some degree of motional freedom.

In this exemplary male assembly110, axial motion of the stepped member126relative to the hollow handling shell138is limited by the ground wall150of the cavity142in the backward direction as well as the constriction of the cavity opening142* in the forward direction. Similarly, axial motion of the capillary conduit122in relation to the rest of the male assembly is limited by the transition128C between the large and smaller diameter section of the passage128in the stepped member126(interacting with the coating layer136or additional protective tubing) in the forward direction as well as the contacting opposing front ends of the first portion126A of the stepped member126and the sealing gasket124, to which it is firmly jointed, in the backward direction.

FIG. 3Bshows the male and female assemblies110,112of the additional embodiment fromFIG. 3A(i) put together individually but disconnected from one another on the left hand side, and (ii) in an engaged condition on the right hand side where the front end of the male assembly110contacts and is, in fact, pressed against the bottom wall116of the first recess step114A in the one-sided port112* of the female assembly112allowing a chromatography fluid flowing through the inner bore of the capillary conduit122to be transmitted further on through tubing to be accommodated in the through-bore118of the one-sided port112* but not shown here for the sake of clarity.

As has been described before with reference to the embodiments inFIGS. 2A to 2C, the first portion126A of the stepped member126as the force-transmitting member exerts axial compressing forces directly on the sealing gasket124that contacts the flat bottom wall116of the first recess step114A in the one-sided port112*, due to the flush alignment together with the front ends of the capillary conduit122and the jacket132, so that this interface is sealed such that no fluid can escape the inner bore of the capillary conduit122radially but will rather flow forward into the adjacent connection tubing (not shown) bound to be accommodated in the through-bore118of the one-sided port112*. Also this slightly altered design renders the pressurization forces being exerted very homogeneously about the circumference of the sealing gasket124and thereby allows for a very tight and reliable seal, suited for high pressure liquid chromatography applications—HPLC, essentially without any significant dead-volume at the interface that could degrade performance, such as by sample carry-over as set out before.

The example implementations fromFIGS. 2A to 2C and 3A to 3Breferred to above show a one-sided port12*,112* to which a male assembly10,110is coupled on only one side thereof, correlating somehow to the depiction inFIG. 1A. Departing from this one-sided approach and rather correlating to the sketch inFIG. 1B,FIG. 4illustrates schematically a female assembly that comprises a receiving member which is accessible to male assemblies210at two (opposing) sides thereof, forming a double-sided union212*. In other words, the capillary conduit of one of the male assemblies210abuts the respective other one and thereby represents the continuation conduit of the respective other male assembly210in this example and vice versa. In the embodiment shown, the double-sided union has a symmetric design in that both recesses have the same size and geometry. A skilled practitioner would understand that also asymmetric designs are conceivable, such as recesses configured for receiving different male assemblies.

In the example ofFIG. 4, however, the two male assemblies210have the same exemplary design as that shown inFIGS. 3A and 3B, though a skilled practitioner will understand that this embodiment is not to be understood restrictively. Favorably, the axial extension of the two internal threads at the respective second recess steps are dimensioned such that, when the male assemblies210have been screwed into the receiving member to the maximum, the respective front ends come to lie at about the center of the union piece212* as shown, thereby ensuring reliable radial guidance during the insertion.

FIG. 5shows a truncated view of a male assembly310having a slightly different configuration than that illustrated in theFIGS. 2 to 4. For the sake of clarity, no female assembly is shown inFIG. 5, it being understood though that the male assembly310depicted would be compatible basically with any of the female assemblies shown in the other embodiments, as the case may be, after some minor structural and dimensional adaptation.

As can be seen, the male assembly310comprises a capillary conduit322, a sealing gasket324(slightly protruding), a jacket332(having a slightly inwardly stepped front end in order to accommodate deformed sealing gasket material) and a short stepped member326as the force-transmitting member. Similar to the embodiment ofFIGS. 3A and 3B, the male assembly310has a hollow handling shell338with an internal passage340for receiving the capillary conduit322which discharges into a cavity342of larger diameter that is dimensioned such as to slidably receive the second portion326B of the stepped member326(shown isolated at the bottom right) and long enough to partly slidably accommodate the conduit-gasket-jacket arrangement shown, which also provides for axial guidance and alignment. The stepped member326takes here the shape of a T-shaped washer (from a lateral cross section view at bottom right). Other shapes than T-shaped are also conceivable, however.

As before, viewed from outside, the hollow handling shell338has two distinct sections. The first section338A comprises an external thread348which is configured to mate with an internal thread foreseen at a suitable receiving member such as to allow for releasable interlocking. The second section338B of the hollow handling shell338has again a larger outer diameter and is designed and configured such as to be easily manually actuated so that it can serve as a finger tightening section, for instance.

In contrast to previous embodiments, there is no cylindrical protrusion from the stepped member body being inserted from rearward into the jacket332and directly contacting a rearward facing surface of the sealing gasket324for exerting axial pressurization thereto. Rather, the rearward facing front end of the sealing gasket324being aligned about flush with the rearward facing front end of the jacket332directly contacts the forward facing front end of the first portion326A of the stepped member326for being directly axially pressurized thereby. In the process of inserting the male assembly310illustrated into a female assembly, it may happen, of course, that the first portion326A compresses the rear part of the sealing gasket324such that it reaches slightly into the cylindrical space formed within the jacket332.

FIG. 6depicts a further embodiment of a male assembly410having a configuration slightly different from those illustrated previously. For the sake of clarity, again no female assembly is shown inFIG. 6, it being understood though that the male assembly410depicted would be equally compatible basically with any of the female assemblies shown in the other embodiments, as the case may be, after some minor structural and dimensional adaptation.

As can be seen, the male assembly410comprises a capillary conduit422, a sealing gasket424(slightly protruding), a jacket432and a stepped member426as the force-transmitting member with a first portion426A and an adjacent second portion426B.

In contrast to embodiments previously described, instead of taking the shape of a cylindrical protrusion from the remainder of the stepped member426that becomes accommodated within a rear part of the hollow cylindrical jacket432, the first portion426A of the stepped member426according toFIG. 6has a cylindrical recess452into which the arrangement of capillary conduit422, sealing gasket424and jacket432is partly slidably accommodated. The sealing gasket424is not covered or surrounded by the jacket432along its full axial extension. At the front end, for example, the sealing gasket424slightly protrudes from the jacket432and capillary conduit422, to be compressed when contacting a bottom surface or a front end of another male assembly in the receiving member, similar to some of the embodiments described further above.

Here however, also at the rear end does the sealing gasket424extend slightly beyond the end face of the jacket432and, when fully received in the recess452in the first portion426A, abuts a forward facing ground surface452* of the recess452. In this manner, the male assembly410can be axially pressurized where the axial forces are conveyed directly into and through the sealing gasket424, without taking a detour via any intermediate elements. The jacket432being properly dimensioned merely provides for axial alignment and guidance within the recess452of the first portion426A. At the outer circumference, the first portion426A of the stepped member426may have an external thread448as indicated, compatible to an internal thread foreseen at the corresponding counter-surface in the receiving member (not shown). The second portion426B of the stepped member426may serve as a finger tightening portion, as has been described before with the respect to some of the other connector embodiments.

FIG. 7Aillustrates another embodiment of a fluid connector according to principles of the invention. As this further embodiment shows a certain degree of similarity with that presented with reference toFIG. 6, the following description will focus on the differences there-between.

FIG. 7Ashows the different elements of a male assembly510disassembled and placed next to one another. The jacket532can be made of a dimensionally stable material, such as stainless steel, and comprises a basically annular cylindrical element dimensioned such as to accommodate the sealing gasket524that takes the form of an annular cylindrical element comprising a stepped front end. A force-transmitting member554takes the form of a short annular cylinder in this example, the inner width of which being adapted to slidably receive a capillary conduit522within and the outer diameter of which being dimensioned such as to being slightly undersized compared to an inner diameter of the jacket532. In the embodiment shown, upon assembly, the stepped front end of the sealing gasket524is bound to slightly protrude from those of both the capillary conduit522as well as of the co-extensive jacket532, as will be explained further below.

A difference between the previous embodiment described with reference toFIG. 6and the instant embodiment is the presence of a hollow handling shell538. The hollow handling shell538comprises an internal passage540for closely but slidably accommodating the capillary conduit522that discharges into a cavity542of larger diameter that is dimensioned such as to slidably receive the jacket532. A design variant compared to previous embodiments includes a flaring rearward part540* of the passage540to enable easier access at this rearward-facing side.

Viewed from outside, the hollow handling shell538has two distinct sections. The first section538A has an outer diameter that is adapted to substantially match the inner diameter of a female assembly512to be depicted inFIG. 7B, and further comprises an external thread548which is configured to mate with an internal thread foreseen at this female assembly512such as to allow for releasable interlocking between the male and female assemblies510,512of this embodiment.

The second section538B of the hollow handling shell538has a larger outer diameter and is designed and configured such as to be easily manually actuated so that it can serve as a finger tightening section. The outer circumferential surface of this second section538B may be textured in order to render a positive haptic feedback when being touched by an operator.

The upper panel ofFIG. 7Bshows the male assembly510put together and ready for being inserted into the female assembly512that takes the shape of a one-sided port in this example and resembles those described in conjunction with previous embodiments so that the particulars do not have to be repeated here.

As can be seen, the force-transmitting member554comes to rest in the cavity542of the hollow handling shell538, while being supported in the upstream axial direction by a forward-facing wall thereof. As can be seen, the jacket532does not come into contact with this forward-facing wall of the cavity542. The capillary conduit522is accommodated in the passage540of the hollow handling shell538and within the inner widths of both the force-transmitting member554as well as the sealing gasket524. As described before, the capillary conduit522and the sealing gasket524are rigidly jointed to one another via opposing radial surfaces while the force-transmitting member554remains not so jointed and engages only slidably with the other elements of the male assembly510thereby retaining some degree of motional freedom. The jacket532is put over, and jointed rigidly merely to the sealing gasket524basically covering it along its whole axial extension. As has been indicated above, the stepped front end of the sealing gasket524slightly protrudes from the front end of the jacket532, ready to be deformed by a counter-surface in the female assembly512upon insertion.

The lower panel ofFIG. 7Bshows the male and female assemblies510,512previously described in an engaged condition where the front end of the male assembly510contacts and is, in fact, pressed against the bottom wall of a first recess step in the one-sided port of the female assembly512allowing a chromatography fluid flowing through the inner bore of the capillary conduit522to be transmitted further on through tubing to be accommodated in the through-bore of the one-sided port but not shown here for the sake of clarity.

As has been described before with reference to various earlier embodiments, the annular cylindrical force-transmitting member554exerts axial compressing forces directly on the likewise annular cylindrical sealing gasket524that contacts the flat bottom wall of the first recess step in the one-sided port thereby sealing this interface such that no fluid can escape the inner bore of the capillary conduit522radially but will rather flow forward into the adjacent connection tubing (not shown) bound to be accommodated in the through-bore of the one-sided port. Also this slightly altered design facilitates the pressurization forces to be exerted very homogeneously about the circumference of the sealing gasket524and thereby allows for a very tight and reliable seal, suited for high pressure liquid chromatography applications—HPLC, essentially without any significant dead-volume at the interface that could degrade performance, such as by sample carry-over as set out before.

In the above-explained embodiments, a pair of mating threads is used to deliver the releasable interlocking function between the male and female assemblies. A skilled practitioner will understand, however, that this function can be achieved in many other suitable ways, such as by a bayonet fitting, for example.

The invention has been shown and described with reference to a number of different embodiments thereof. It will be understood, however, that various aspects or details of the invention may be changed, or various aspects or details of different embodiments may be arbitrarily combined, if practicable, without departing from the scope of the invention. Generally, the foregoing description is for the purpose of illustration only, and not for the purpose of limiting the invention which is defined solely by the appended claims.