Connector apparatus for electrically connecting conductor devices, in particular in a superconducting condition, conductor arrangement and method of using the connector apparatus

Abstract

A connector apparatus 100 for electrically connecting conductor devices (1, 2), in particular in a superconducting condition, comprises a connector receptacle (10) for accommodating a first conductor device (1) and a second conductor device (2) with overlapping conductor sections (1A, 2A) thereof, and a first pivotable pressing clamp (20) having a first clamp shaft (21) and at least one first clamp edge (22) and being arranged for applying a contact pressure on the overlapping conductor sections (1A, 2A) of the first conductor device (1) and the second conductor device (2) so that the overlapping conductor sections (1A, 2A) directly contact each other, wherein the connector receptacle (10) comprises a base portion (11) providing a support for the first and second conductor devices (1, 2) and a bearing portion (12) being arranged adjacent to the base portion (11) for accommodating the first clamp shaft (21) of the first pressing clamp (20), and the first pressing clamp (20) is adapted for a pivoting motion between a clamp condition, wherein the at least one first clamp edge (22) presses the overlapping conductor sections (1A, 2A) against the base portion (11), and a release condition, wherein the at least one first clamp edge (22) of the first pressing clamp (20) releases the overlapping conductor sections (1A, 2A). Furthermore, an electrical conductor arrangement including the connector apparatus (100) and a method of using the connector apparatus (100) are described.

Description

[0001] CONNECTOR APPARATUS FOR ELECTRICALLY CONNECTING CONDUCTOR DEVICES, IN PARTICULAR IN A SUPERCONDUCTING CONDITION, CONDUCTOR ARRANGEMENT AND METHOD OF USING THE CONNECTOR APPARATUS

[0002] Field of the invention

[0003] The invention relates to a connector apparatus for electrically connecting conductor devices, in particular in a superconducting condition, an electrical conductor arrangement including the connector apparatus, and a method of using the connector apparatus for electrically connecting conductor devices. Applications of the invention are available in the fields of measuring techniques, signal processing, and electronic and / or cryogenic setups, in particular for connecting electrical components via a superconducting, resistance-free path. For example, the invention may be used for coupling superconducting sensors and / or superconducting qubits to control and readout electronics, e.g., in superconducting qubits-based quantum computing.

[0004] Prior art

[0005] In the present specification, reference is made to the following prior art illustrating technical background of the invention and related techniques:

[0006] [1] A. B. Walter et al. "Laminated NbTi-on-Kapton Microstrip Cables for Flexible Sub-Kelvin RF Electronics" in IEEE Transactions on Applied Superconductivity, vol. 28, No. 1, January 2018;

[0007] [2] European patent application No. 23188319.0 (not published on priority date of present disclosure); and

[0008] [3] US 6045 396 A.

[0009] In connection with cryogenic experiments, low-impedance superconducting sensors, like transition edge sensors, are generally known in the prior art. Reading out these types of sensors typically requires a superconducting path, including cables and connectors, with resistance-free contacts in series with the sensor. Moreover, since these sensors are typically operated at cryogenic temperatures in dilution refrigerators, the interconnections between the components should be as compact as possible to fit in the limited space available in such complex machines. As a particular example, CRESST is a cryogenic experiment that searches for Dark Matter particles by measuring tiny temperature variations when an interaction with its detectors occurs. These temperature variations are measured using superconducting films operated inside their phase transition, at temperatures around 10 mK to 20 mK, where they correspond to larger variations in resistance. Due to the low impedance of these sensors (about 10 to 100 mOhm), they are read out in current using SQUIDs (Superconducting Quantum Interference Devices). The bias circuit of these detectors requires the use of superconducting wires, given that any additional resistance present in these circuits would either increase noise or decrease the detector responsivity. With the need for increasing the number of readout channels, as the experiment expands, the number of wires also increases to very large values, making it difficult to handle.

[0010] A generally known concept of using superconducting wires is to use twisted pairs of NbTi wires, interwoven in a polyamide texture, as a superconducting cable. This allows for the manufacturing of long cables of several meters, with the main limitation of being bulky and massive. The connection of such cables to the readout electronics is, however, complex: pure NbTi wires, with no matrix, are very difficult to solder to standard connectors, and for this reason, usually the single wires of the twisted pairs are individually screwed or wired to a printed circuit board, which is a time-consuming procedure that is easily subject to failures (e.g., a wire might break if it is screwed too tightly).

[0011] In these circumstances, the use of superconducting flat cables provides an alternative solution. Superconducting flat cables offer unprecedented advantages for establishing fully superconducting connections, especially when dealing with a large number of signal channels, particularly when running through constrained spaces.

[0012] Superconducting flat cables may be produced through the lamination of NbTi foils on Kapton substrates (see e.g., [1]) or by the deposition of Nb on Polyimide-based films using sputtering techniques. Both of these techniques, however, - in addition to the drawback of requiring complex and time-consuming production steps - only resulted in prototypes with a length of up to several cm and up to about ten traces. Moreover, the termination of such cables to a printed circuit board (PCB) can typically only be bonded using a superconducting solder (e.g. Pb or In) with the risk of adding parasitic resistance to ground. To overcome the limitations of laminated or sput- tered superconducting flat cables and in particular for avoiding space constraints posed by cryostats, an alternative superconducting flat cable including self-supporting wires is proposed in [2] (not published on priority date of present disclosure).

[0013] There is a need for practical solutions for connecting superconducting conductors, like wires or flat cables. While flat cable connectors for room temperature applications are generally known, they either do not work reliably, are not physically robust or have large residual contact resistances at cryogenic temperatures.

[0014] An electrical cryogenic connector system for flex cables is disclosed in [3], The connector system comprises a male connector and a corresponding female connector, wherein the male and female connectors each comprise multiple parallel beryllium copper contacts. While the contacts of the male connector are configured in a curved geometry that curves outwardly from said male connector, the contacts of the female connector lie entirely flat. A first flex cable is connected to the male connector, wherein individual leads of the first flex cables are soldered to the respective contacts of the male connector. Correspondingly, a second flex cable is connected to the female connector, wherein individual leads of the second flex cable are soldered to the respective contacts of the female connector. In a connected state, the male and female connectors are oriented with said contacts directly facing one another, such that each conductor of the male connector is in parallel with a corresponding contact of the female connector. The system further comprises a fastening means for fastening the male and female connectors in sandwiched relationship to compress the curved contacts of the male connector and to maintain a positive contact pressure therewith. Besides the disadvantage that connecting the flex cables to the respective connectors is time-consuming, the indirect connection of the cables via the connectors, and in particular the soldering process required to secure the cables to the connectors, is prone to introducing parasitic resistances and may prevent a superconducting, resistance-free path. As a further disadvantage, the fastening means is based on screw connections, which require the time consuming application of tools for connecting cables.

[0015] Objective of the invention

[0016] The objective of the invention is to provide an improved connector apparatus for electrically connecting conductor devices, in particular in a superconducting condition, an improved electrical conductor arrangement including the connector apparatus, and / or an improved method of using the connector apparatus for electrically connecting conductor devices, which avoid disadvantages of conventional techniques. In particular, the connector apparatus and / or the conductor arrangement are to be capable of connecting multiple contacts at once, providing an easy, reliable, stable and / or compact solution for connecting electrical conductors, in particular for creating a zero-resistance path in the superconducting condition, and / or connecting or disconnecting conductors without an application of a complex tool.

[0017] Summary of the invention

[0018] These objectives are correspondingly solved by a connector apparatus for electrically connecting conductor devices, in particular in a superconducting condition, an electrical conductor arrangement including the connector apparatus, and a method of using the connector apparatus for electrically connecting conductor devices, comprising the features of the independent claims, respectively. Preferred embodiments and applications of the invention arise from the dependent claims.

[0019] According to a first general aspect of the invention, the above objective is solved by a connector apparatus, being adapted for electrically connecting conductor devices, in particular in a superconducting condition. The connector apparatus comprises a connector receptacle being arranged for accommodating a first conductor device and a second conductor device with overlapping conductor sections thereof, and a first pivotable pressing clamp having a first clamp shaft and at least one first clamp edge and being arranged for applying a contact pressure on the overlapping conductor sections of the first conductor device and the second conductor device accommodated by the connector receptacle so that the overlapping conductor sections of the first conductor device and the second conductor device directly contact each other. The connector receptacle comprises a base portion providing a support for the first conductor device and the second conductor device and a bearing portion being arranged adjacent to the base portion for accommodating the first clamp shaft of the first pressing clamp. The first pressing clamp is adapted for a pivoting motion between a clamp condition (or: clamp or closed state), wherein the at least one first clamp edge of the first pressing clamp presses the overlapping conductor sections of the first conductor device and the second conductor device against the base portion, and a release condition (or: release or open state), wherein the at least one first clamp edge of the first pressing clamp releases the overlapping conductor sections of the first conductor device and the second conductor device.

[0020] According to a second general aspect of the invention, the above objective is solved by an electrical conductor arrangement, including a first conductor device, a second conductor device and the connector apparatus according to the first general aspect of the invention or an embodiment thereof, wherein the first and second conductor devices are electrically connected via the connector apparatus.

[0021] According to a third general aspect of the invention, the above objective is solved by a method of using the connector apparatus according to the first general aspect of the invention or an embodiment thereof, comprising the steps of arranging a first conductor device and a second conductor device in the conductor receptacle such that longitudinal conductor sections of the first and second conductor devices overlap each other in the conductor receptacle, applying a contact pressure with the first pressing clamp and pressing the first and second conductor devices against each other, so that the overlapping conductor sections of the first and second conductor devices directly contact each other in the overlapping portion, and arranging the first conductor device and the second conductor device connected via the connector apparatus in an environment with a reduced temperature, so that an electrically superconducting connection between the first conductor device and the second conductor device is obtained.

[0022] The connector apparatus is configured for electrically connecting the conductor devices, which may comprise e.g., at least one of a single wire, preferably with a flat conductor section, a flat cable including at least one conducting wire, preferably multiple conducting wires, and a printed circuit board (PCB). For example, a flat cable preferably may be connected with another flat cable or with a PCB. Preferably, each of the conductor devices may have at least one conductor element having a flat shape at the overlapping conductor sections, in particular the overlapping end sections, of the conductor device. At least one of the conductor devices preferably may comprise a cable including multiple (at least two) conductor wires, in particular self-supporting conductor wires, with electric superconductivity at the operation temperature (also called superconducting wires in the following). Particularly preferred, at least one of the conductor devices may comprise a flat cable as disclosed in [2]

[0023] Particularly preferred, materials of the connector apparatus and the conductor devices may be selected such that an electrically superconducting connection between the conductor devices accommodated by the connector apparatus is obtained at temperatures below 10K, preferably below 2K. Advantageously, the connector apparatus connects conductor devices providing the superconducting path between components, in particular electrical devices, within a low temperature environment and / or a sectional superconducting path between a component, in particular electrical device, in a low temperature environment and a component, in particular electrical device, in a normal temperature environment. The connector apparatus also may be employed exclusively within a normal temperature environment. The conductor devices connectable with the connector apparatus may comprise cables connected with an application site, e. g. electrical devices, like sensors. Optionally, one of the conductor devices may be a component of the connector apparatus, as outlined with further details below.

[0024] At least at the position of the first pressing clamp, the connector receptacle may have a transverse direction and a longitudinal direction, wherein the transverse direction is defined by the direction of the first clamp shaft and the longitudinal direction may be substantially perpendicular to the transverse direction. The longitudinal direction preferably is equal to the extension of the conductor devices at the overlapping conductor sections thereof. Preferably, the connector receptacle may have a straight shape along the longitudinal direction. Alternatively, in particular if multiple pressing clamps are provided, the connector receptacle may have an angled shape, as outlined below.

[0025] The first (and optionally each further) pressing clamp generally is a solid mechanical element being pivotable about the clamp shaft between the release and clamp conditions. In the release condition, a gap between the at least one clamp edge and the base portion of the connector receptacle provides sufficient space so that the conductor devices are released. In particular, the conductor devices can be introduced into the gap simultaneously and the overlapping conductor sections are movable into or out of a stacked arrangement thereof in the gap. In the clamp conditions, the gap is narrowed by the pivoting movement of the at least one clamp edge towards the base portion, so that the overlapping conductor sections conductor devices are pressed against the base portion. Advantageously, the connector receptacle and the pressing clamp may be dimensioned for creating a clamp force such the overlapping conductor sections conductor devices are secured against any movements and in particular against disconnecting from the connector apparatus.

[0026] Preferably, the position of the first clamp shaft and the configuration of the first clamp edge may be selected such that a location of pressing the first clamp edge against the overlapping conductor sections of the conductor devices is displaced relative to the axis of the first clamp shaft along the longitudinal direction by a predetermined displacement away from the axis of the first clamp shaft. Advantageously, the respective clamp edge still exerts sufficient clamping force in the closed clamp position, while simultaneously self-locking is obtained, which excludes unintentional opening of the first pressing clamp.

[0027] The first (and optionally each further) pressing clamp comprises at least one clamp edge. Accordingly, a single clamp edge may be provided, extending in the transverse direction. Alternatively, multiple clamp edges may be provided. Preferably, the multiple clamp edges are arranged in parallel, extending in the transverse direction. Two or more clamp edges may have advantages in terms of increasing the clamping effect of the pressing clamp.

[0028] The term "conductor section" preferably may refer to end sections of the conductor devices, i.e., the conductor devices may be connected by the connector apparatus at the final ends thereof. Depending on the application of the connector apparatus and the particular application conditions, the connector apparatus may be adapted for connecting the conductor devices along a longitudinal extension thereof with a distance from their ends. For instance, an end section of one of the conductor devices may be connected with a conductor section of the other conductor device at any position along the longitudinal extension thereof. Alternatively, both conductor devices may be connected at any position along the longitudinal extensions thereof.

[0029] Preferably, the connector apparatus may employ a press contact between the conductor devices, said press contact being applied at least by the pressing clamp pressing the conductor sections of the conductor devices against the connector receptacle. Preferably, the connector apparatus, in particular the connector receptacle and at least the first pressing clamp, may be adapted for creating a direct press contact between the conductor devices. For instance, conducting wires or leads of the superconducting flat cable may be directly pressed onto conducting elements of a PCB or onto conducting wires or leads of another second superconducting flat cable, preferably achieving a zero-resistance path and eliminating any residual resistance arising from connection joints. The term "zero-resistance" in particular may refer to a contact resistance between the touching parts of the conductor devices, which is zero or reduced to a disappearing residual amount (neglectable in the particular application task). According to the preferred configuration of the connector apparatus for creating the direct press contact, the connector apparatus is adapted for supporting the connected conductor devices such that the conductor sections thereof overlap and directly contact each other. Building on the concept of a belt buckle, the inventors provide a pressing mechanism (pressing clamp) using a flap, which may be straight or notched and which may ensure a secure and reliable connection between the conductor devices, like two flat cables or a flat cable and a PCB. Furthermore, if the cable is made with a superconducting shield, e.g., made of aluminium, on a side opposite to a location of superconducting traces (like disclosed in [2]) the flap may also provide an electrical connection of the shield to the ground. This design provides a fully superconducting connection that is reliable, very quick and easy to use, making it extremely handy when making a large number of connections.

[0030] Further advantages of the inventive connector apparatus are obtained by requiring less space than conventional connectors, the capability of providing the superconducting path within a low temperature environment or between a low temperature environment and a surrounding at normal temperature, facilitating shielding against electromagnetic fields, the capability of reducing cross-talk between conductors, facilitating connecting the conductor device with hardware components, like a PCB, having improved mechanical stability and / or providing increased connector lengths. Furthermore, the method of manufacturing the connector apparatus in particular is characterized by simplified process steps and improved variability in terms of number and lengths of connectors.

[0031] According to a preferred embodiment of the invention, the connector receptacle may comprise a U profile extending in the longitudinal direction and having a base wall providing the base portion and two side walls protruding from the base portion and providing the bearing portion. Advantageously, the U profile facilitates the introduction of the conductor devices into the connector apparatus. Particularly preferred, the two side walls have a distance perpendicular to the longitudinal direction, said distance being selected for an alignment of the overlapping conductor sections of the first conductor device and the second conductor device. Thus, an inner width of the U profile may be adapted to the width of the conductor sections, e.g., end sections of the conductor devices to be connected. With this embodiment, the U profile shape advantageously provides defined conductor positions.

[0032] Preferably, the first (and optionally each further) pressing clamp comprises a lever plate, wherein the lever plate has a first plate end, wherein the first clamp shaft is coupled with the first plate end and the at least one first clamp edge is arranged at the first plate end at a side thereof facing to the base portion, and said lever plate has a free second plate end. Advantageously, the lever plate facilitates the handling of the connector apparatus, e.g., by manual actuation or by actuation with a simple tool.

[0033] Further advantages of the invention are obtained from the variability in designing the at least one first clamp edge. According to a first variant, the at least one first clamp edge may comprises a flat knife edge. The flat knife edge may have advantages in terms of providing a homogeneous application of force in the contact field between the conductor devices. According to an alternative variant, the at least one first clamp edge may comprise a notched knife edge. The notched knife edge may have advantages in terms of reducing the contact area and correspondingly locally increasing the contact pressure and improving the contact. Furthermore, the notched knife edge may provide a better tolerance with regard to the flatness of the clamp edge.

[0034] According to a further preferred embodiment of the invention, the first clamp shaft may be made of an elastically deformable material, in particular steel or brass. Advantageously, the clamp shaft of the first (and optionally each further) pressing clamp may provide a spring effect in pressing the overlapping conductor sections against the base portion of the connector receptacle. The clamp shaft may be slightly bent in the clamping condition of the connector apparatus.

[0035] Advantageously, the connector may be made from a wide choice of materials. Preferably, the connector receptacle is made of Cu and / or brass. Copper and brass have advantages as they have well known material properties in particular in cryogenic applications, offer adaptability to different needs, facilitate PCB thermalisation, and provide material radiopurity (which is of utmost significance e.g., in rare event search experiments).

[0036] If, according to a further variant of the invention, the base wall of the connector receptacle may have at least one alignment projection being arranged for blocking movements of the first conductor device and the second conductor device along the longitudinal direction, advantages for additionally improving the mechanical stability of the connection of conductor devices are obtained.

[0037] According to a further advantageous embodiment of the invention, the connector apparatus further may be provided with a holding frame comprising a plate-shaped element with a lateral profile, wherein the holding frame is arranged in the connector receptacle and the lateral profile is configured for an engagement with at least one of the connector devices in the clamp condition. Advantageously, the holding frame allows blocking a detachment of the engaged connector device in the clamp condition.

[0038] As mentioned above, according to a basic embodiment of the invention, the connector apparatus may be adapted for connecting two conductor devices (single clamp embodiment), in particular for connecting two flat cables directly. Alternatively, the connector apparatus may be adapted for connecting more than two, in particular three conductor devices (multiple clamp embodiment), in particular for connecting two flat cables via a PCB.

[0039] According to the multiple clamp embodiment, the connector receptacle is arranged for accommodating the first conductor device, the second conductor device and a third conductor device with overlapping conductor sections of the second conductor device and the third conductor device, and a second pivotable pressing clamp is provided, wherein said second pivotable pressing clamp has a second clamp shaft and at least one second clamp edge being arranged for applying a contact pressure on the overlapping conductor sections of the second conductor device and the third conductor device accommodated by the connector receptacle so that the overlapping conductor sections of the second conductor device and the third conductor device directly contact each other, wherein the base portion provides a support for the first, second and third conductor devices and the bearing portion is arranged for accommodating the first clamp shaft of the first pressing clamp and the second clamp shaft of the second pressing clamp, and the second pressing clamp is adapted for a pivoting motion between a clamp condition, wherein the at least one second clamp edge of the second pressing clamp presses the overlapping conductor sections of the second conductor device and the third conductor device against the base portion, and a release condition, wherein the at least one second clamp edge of the first pressing clamp releases the overlapping conductor sections of the second conductor device and the third conductor device.

[0040] In terms of the electrical conductor arrangement employing the multiple clamp embodiment, a third conductor device is coupled with the connector apparatus, wherein the second conductor device is arranged in the connector apparatus and the third conductor device is electrically connected with the second conductor device. Thus, with the multiple clamp embodiment of the connector apparatus, the second conductor device may be fixedly connected with the connector receptacle, or it may be separably arranged in the connector receptacle. For connecting two flat cables via a PCB with the multiple clamp embodiment, the cables provide the first and third conductor devices, while the PCB is the second conductor device. Preferably, the at least one second pressing clamp may be configured like the at least one first pressing clamp. In particular, the second pressing clamp may have the same configuration and size like the first pressing clamp, but may be arranged with an opposite pivoting direction relative to the first pressing clamp.

[0041] With the multiple clamp embodiment, the connector receptacle may have a straight shape, wherein the connector receptacle completely extends along a single longitudinal direction thereof. Alternatively, the connector receptacle may have an angled shape, wherein the longitudinal direction at the first pressing clamp deviates from the longitudinal direction at the second pressing clamp. Advantageously, the angled multiple clamp embodiment may introduce an angle, e.g. a 90° angle into a connection of conductor devices.

[0042] Brief description of the drawings

[0043] Further details and advantages of the invention are described in the following with reference to the attached drawings, which schematically show in:

[0044] Figure 1: a side view of a connector apparatus according to embodiments of the invention

[0045] (single clamp embodiment);

[0046] Figure 2: a top view of the connector apparatus according to Figure 1;

[0047] Figure 3: a perspective view of a connector apparatus in a release condition according to embodiments of the invention (multiple clamp embodiment);

[0048] Figure 4: a perspective view of the connector apparatus of Figure 3 in a clamp condition;

[0049] Figure 5: a holding frame included in a connector receptacle of a connector apparatus according to embodiments of the invention

[0050] Figure 6: a lever plate included in a pressing clamp of a connector apparatus according to embodiments of the invention;

[0051] Figure 7: sectional views of a connector receptacle of a connector apparatus according to embodiments of the invention; and Figure 8: sectional views of an alternative connector receptacle of a connector apparatus according to embodiments of the invention.

[0052] Preferred embodiments of the invention

[0053] Features of preferred embodiments of the invention are described in the following with exemplary reference to connecting flat cables and / or PCBs with the connector apparatus. It is emphasized that the invention is not restricted to the described embodiments, but can be implemented with modified characteristics, e.g. with regard to the shape of the conductor devices to be connected, the number and / or arrangement of superconducting leads or wires, and / or the materials of the connector apparatus. Furthermore, it is noted that the drawings are schematic illustrations only, which are not to scale. In practice, the sizes and shapes of components of the connector apparatus may be adapted in dependency on the particular application conditions. Although the drawings refer to connector apparatuses with a straight shape only, it is emphasized that the invention correspondingly can be implemented with an angled configuration.

[0054] According to preferred embodiments of the invention, the connector apparatus may be employed for connecting connector devices as described in [2], which is introduced into the present disclosure by reference, especially with regard to the configuration of the flat cable, in particular with regard to the end sections and shielding thereof.

[0055] Figures 1 and 2 show a sectional side view and a top view of features of the single clamp embodiment of the inventive connector apparatus 100. The connector apparatus 100 comprises a U shaped connector receptacle 10 and a first pressing clamp 20. The connector apparatus 100 is configured for connecting end sections 1A, 2A of first and second conductor devices 1, 2. The end sections 1A, 2A overlap each other along the longitudinal direction (z-direction) of the connector apparatus 100. A length of overlap along the longitudinal direction may be selected e.g., in a range from 1 mm to an upper, conductor device specific limit chosen depending on application conditions.

[0056] The connector receptacle 10 has the rectangular U profile which is provided by a base portion 11 and a bearing portion 12. The base portion 11 comprises a rectangular plane base wall, and the bearing portion 12 comprises two rectangular plane side walls, which protrude from the base wall at opposite borders thereof. The side walls of the bearing portion 12 include through-holes 13 (see in particular Figure 2), which are arranged for accommodating a first clamp shaft 21 of the first pressing clamp 20 in a pivotable manner (see in particular Figure 2). The first clamp shaft 21 is secured in the through-holes 13 for blocking a movement in transverse direction perpendicular to the longitudinal direction. The bearing portion 12 carries the first pressing clamp 20 in an articulated manner. The connector receptacle 10 preferably is monolithically made of a single material, for instance by bending a plate according to the arrangement of the base and side walls.

[0057] The first pressing clamp 20 comprises a lever plate 23, including a first plate end 24 and a second plate end 25. The lever plate 23 has a rectangular shape extending along the longitudinal direction of the connector receptacle 10. Preferably, the transverse width of the lever plate 23 may be smaller than the inner width of the U profile of the connector receptacle 10. At the first plate end 24, the lever plate 23 has a transverse through-hole 26 (see Figure 1) accommodating the first clamp shaft 21. Furthermore, the lever plate 23 has a first clamp edge 22 at the first plate end 24 on a plate surface facing towards the base portion 11. A lateral width of the first clamp edge 22 may be equal to the width of the lever plate 23 (as shown) or smaller (see Figures 4, 6B) or larger than the width of the lever plate 23. The first clamp edge 22 has a triangular profile with a tip facing to the base portion 11 in the clamp condition of the first pressing clamp 20. Accordingly, the first clamp edge 22 provides a flat knife edge 27 extending over the full width of the conductor devices 1, 2 to be connected.

[0058] Figures 1 and 2 illustrate the first pressing clamp 20 in the clamp condition, wherein the first clamp edge 22 presses the overlapping end sections 1A, 2A of the first and second conductor devices 1, 2 against the base wall of the base portion 11. Additionally, Figure 1 illustrates the release condition, wherein the lever plate 23 is pivoted (shown with dashed lines). In the release condition, the flat knife edge 27 of the first clamp edge 22 releases the stack of the end sections 1A, 2A of the first and second conductor devices 1, 2, so that they can be disconnected.

[0059] The position of the first clamp shaft 21 and the configuration of the first clamp edge 22 are set such that the flat knife edge 27 is displaced relative to the axis of the first clamp shaft 21 along the longitudinal direction by a displacement D towards the short first plate end 24. Accordingly, self-locking of the first pressing clamp 20 is obtained, as turning the lever plate 23 to the release condition requires a short phase of reducing a distance of the flat knife edge 27 from the base portion 11 and thus applying an additional pressing force which is to be exerted by the person or tool opening the first pressing clamp 20. Figures 3 and 4 illustrate perspective cut views of the multiple clamp embodiment of the connector apparatus 100 in the release condition (Figure 3) and the clamp condition (Figure 4). The embodiments of Figures 3 and 4 are adapted for connecting three conductor devices 1, 2 and 3 to each other. For illustrative purposes, the third conductor device 3 is shown in Figure 4 only. With preferred applications of the invention, the first and third conductor devices 1, 3 may comprise flat cable's, e.g., as described in [2], while the second conductor device 2 may comprise a PCB integrated in the connector apparatus 100. The second conductor device 2 (e.g., the PCB) may be fixedly connected to the connector receptacle 10 (as shown), or it may be configured for a separation from the connector receptacle 10.

[0060] At a first end of the second conductor device 2, the first pressing clamp 20 is provided, which is configured as described with reference to Figures 1 and 2 above. The first pressing clamp 20 is arranged for creating a direct press contact between the end section 1A of the first conductor device 1 with the end section 2A of the second conductor device 2.

[0061] At the second, opposite end of the second conductor device 2, the second pivotable pressing clamp 30 is provided, which has the same configuration like the first pressing clamp 20. Accordingly, the second pressing clamp 30 comprises a second clamp shaft 31, a second clamp edge 32 and a second lever plate 33 (see in particular Figure 3). In relation to the first pressing clamp 20, the second pressing clamp 30 may be arranged for the pivoting movement with an opposite direction.

[0062] Figures 3 and 4 further show an alignment projection 14 which protrudes from the base portion 11 into the inner space of the U profile of the connector receptacle 10. The second conductor device 2 and an optional holding frame 15 (see below) include through-holes accommodating the alignment projection 14 with form fit. With the alignment projection 14, any movements of the second conductor device 2 and the optional holding frame 15 along the longitudinal direction are blocked.

[0063] Optionally, according to further preferred embodiments of the invention, the connector apparatus 100, e. g. according to one of the Figures 1 to 4 and 7 to 8, may be provided with the holding frame 15 (see Figures 3, 4 and 5), which is arranged for further blocking a movement of at least one of the conductor devices 1, 2 and 3 connected as conduits with the connector apparatus 100. The holding frame 15 comprises a plate-shaped element arranged in the connector receptacle 10 parallel to the base portion 11 and extending in the longitudinal direction of the connector apparatus 100 towards an outer side of each the pressing clamps 20, 30. The holding frame 15 may be coupled with the connector receptacle 10 by the alignment projection 14 and / or by the clamping action of at least one of the pressing clamps 20, 30. As shown in Figure 4, the width of the clamp edge, e.g., the first clamp edge 22, may be smaller than the width of the lever plate 23, thus providing space for arranging the holding frame 15.

[0064] As shown with further details in Figure 5, the holding frame 15 has a lateral profile at an outer frame section 16 thereof. The outer frame section 16 of the holding frame 15 at an outer side of at least one of the pressing clamps 20, 30 (as shown in the left part of Figure 3) is engaged with a recess IB in the first conductor device 1. Accordingly, with the pressing clamp 20 in the clamp condition, the first conductor device 1 cannot be drawn out of the connector apparatus 100. The lateral profile is selected in dependency on a lateral profile of the end section of the conductor device engaged with the holding frame 15. As an example, the lateral profile at the frame section 16 of Figure 5 is adapted to the shape of flat cables disclosed in [2],

[0065] Figures 3 to 5 show the frame section 16 with the lateral profile at one end of the holding frame 15 only. Alternatively, frame sections 16 with lateral profiles may be provided at both ends of the holding frame 15.

[0066] Figures 6A and 6B illustrate variants of the lever plate 23, which may be provided with the flat knife edge 27 extending over the whole width of the lever plate 23 (Figure 6A) or which may be arranged in a middle portion of the lever plate 23 only (Figure 6B). Furthermore, a step shape may be provided at the second end 25 of the lever plate 23 (Figure 6A), which may facilitate a manual handling or a tool handling of the lever plate 23, in particular for pivoting thereof between the clamp and release conditions.

[0067] Figures 7 and 8 illustrate further details of the connector receptacle 10 of the single clamp embodiment (Figure 7) or the multiple clamp embodiment (Figure 8). Figures 7A and 8A show cross sectional views of the connector receptacle 10, while Figures 7B / 7C and 8B / 8C show top and side sectional views of the connector receptacle 10.

[0068] In addition to the base and bearing portions 11, 12 with the through-holes 13 in the sidewalls of the bearing portion 12, Figure 7 shows that the alignment projection 14 may be provided also with the single clamp embodiment. Figure 8 additionally shows a recess 17 in the base portion 11, which may be provided for facilitating the release of the connection with a conductor device (see also Figures 3 and 4).

[0069] The connector apparatus 100 of the above embodiments may be made of e.g., copper or brass. Using in particular copper allows for exceptional adaptability, enabling customisation to meet specific requirements while facilitating efficient thermalisation of the PCB. The inherent thermal properties of copper make the connector robust, enabling it to withstand repeated thermal cycles without compromising its functionality.

[0070] The sizes of the components of the connector receptacle 10 and the first pressing clamp 20 may be selected in dependency on the application of the connector apparatus 100. As an example, for connecting connector devices 1, 2 provided by flat cables, e. g., as described in [2], the inner width of the U profile of the connector receptacle 10 may be selected in a range from 2 mm, e. g. 4 mm or 8 mm to 10 mm or more.

[0071] Furthermore, the pressing clamp generally may be dimensioned such that the gap between the clamp edge, e.g., the flat knife edge 27 of the first clamp edge 22, and the inner surface of the base portion 11 in the clamp state (without the overlapping conductor sections is equal to or smaller than the sum of thicknesses of the overlapping conductor sections of the conductor devices to be connected. Preferably, the ratio of the gap and the sum of thicknesses is selected in a range from 0.9 to 1. For example, for connecting a PCB having a thickness of 1.75 mm and a cable having a thickness of 0.245 mm, the pressing clamp may be dimensioned such that the gap is set in a range from 1.8 mm to 1.995 mm.

[0072] One advantageous application of the inventive connector apparatus is in cryogenic rare event search experiments, where material radiopurity is pivotal in achieving accurate and reliable results. Copper's radiopurity and compatibility with cryogenic temperatures make it an exceptionally fitting choice for such experiments, ensuring minimal interference and maintaining the integrity of the experiment's objectives.

[0073] In following, further advantages of the invention are summarized.

[0074] 1. Capability of fully Superconducting Connections: The cryo-connector ensures fully superconducting connections between two superconducting flat cables or a superconducting flat cable and a Printed Circuit Board (PCB), eliminating any residual resistance. 2. Easy to use Pressing Mechanism: Inspired by the simplicity of a belt buckle, the inventive pressing mechanism, e.g., with a straight or notched flap, allows for quick and easy connections, saving time during assembly and reducing the risk of errors.

[0075] 3. Cryogenic Compatibility: possibility of using copper, an ideal material for cryogenic applications, the cryo-connector maintains excellent performance even at extremely low temperatures, making it suitable for use in cryogenic environments.

[0076] 4. Robust to Thermal Cycles: The connector's copper construction, thanks to its inherent thermal properties, ensures exceptional resilience against repeated thermal cycles, enhancing the longevity and reliability of the interconnect.

[0077] 5. Versatile Adaptability: machinability of copper offers great advantage to the cryo-connector in terms of being adapted to meet specific requirements, making it highly versatile for various superconducting flat cable configurations and applications.

[0078] 6. Suitable for Low Background Applications: With high radiopurity and compatibility with cryogenic rare event search experiments, the copper material usable in the connector is ideal for experiments where low background is pivotal.

[0079] Although the invention has been described with reference to certain exemplary embodiments, it is evident to a person skilled in the art that various changes can be implemented and equivalents can be used as substitutes without departing from the scope of the invention. Consequently, the invention is not to be limited to the disclosed exemplary embodiments but is to comprise all exemplary embodiments falling within the scope of the attached patent claims. More particularly, the invention also claims protection for the subject-matter and the features of the dependent claims independently of the referenced claims.

Claims

Claims1. Connector apparatus (100), being adapted for electrically connecting conductor devices (1, 2), in particular in a superconducting condition, comprising- a connector receptacle (10) being arranged for accommodating a first conductor device (1) and a second conductor device (2) with overlapping conductor sections (1A, 2A) thereof, and- a first pivotable pressing clamp (20) having a first clamp shaft (21) and at least one first clamp edge (22) and being arranged for applying a contact pressure on the overlapping conductor sections (1A, 2A) of the first conductor device (1) and the second conductor device (2) accommodated by the connector receptacle (10) so that the overlapping conductor sections (1A, 2A) of the first conductor device (1) and the second conductor device (2) directly contact each other, wherein- the connector receptacle (10) comprises a base portion (11) providing a support for the first conductor device (1) and the second conductor device (2) and a bearing portion (12) being arranged adjacent to the base portion (11) for accommodating the first clamp shaft (21) of the first pressing clamp (20), and- the first pressing clamp ( 20) is adapted for a pivoting motion between a clamp condition, wherein the at least one first clamp edge (22) of the first pressing clamp (20) presses the overlapping conductor sections (1A, 2A) of the first conductor device (1) and the second conductor device (2) against the base portion (11), and a release condition, wherein the at least one first clamp edge (22) of the first pressing clamp (20) releases the overlapping conductor sections (1A, 2A) of the first conductor device (1) and the second conductor device (2).

2. Connector apparatus according to claim 1, wherein- the connector receptacle (10) comprises a U profile extending in a longitudinal direction and having a base wall providing the base portion (11) and two side walls protruding from the base portion (11) and providing the bearing portion (12).

3. Connector apparatus according to claim 2, wherein- the two side walls have a distance perpendicular to the longitudinal direction, said distance being selected for an alignment of the overlapping conductor sections (1A, 2A) of the first conductor device (1) and the second conductor device (2).

4. Connector apparatus according to one of the foregoing claims, wherein- the first pressing clamp (20) comprises a lever plate (23), wherein- said lever plate (23) has a first plate end (24), wherein the first clamp shaft (21) is coupled with the first plate end (24) and the at least one first clamp edge (22) is arranged at the first plate end (24) at a side thereof facing to the base portion (11), and- said lever plate (23) has a free second plate end (25).

5. Connector apparatus according to one of the foregoing claims, wherein- the at least one first clamp edge (22) comprises a flat knife edge.

6. Connector apparatus according to one of the foregoing claims, wherein- the at least one first clamp edge (22) comprises a notched knife edge.

7. Connector apparatus according to one of the foregoing claims, wherein- the first clamp shaft (21) is made of an elastically deformable material, in particular steel or brass.

8. Connector apparatus according to one of the foregoing claims, wherein- the connector receptacle (10) is made of Cu or brass.

9. Connector apparatus according to one of the claims 2 to 8, wherein- the base wall has at least one alignment projection (13) being arranged for blocking movements of the first conductor device (1) and the second conductor device (2) along the longitudinal direction.

10. Connector apparatus according to one of the foregoing claims, further comprising- a holding frame (15) comprising a plate-shaped element with a lateral profile, wherein the holding frame (15) is arranged in the connector receptacle (10) and the lateral profile is configured for an engagement with at least one of the connector devices (1, 2) in the clamp condition.

11. Connector apparatus according to one of the foregoing claims, wherein- the connector receptacle (10) is arranged for accommodating the first conductor device (1), the second conductor device (2) and a third conductor device (3) with overlapping conductor sections (2A, 3A) of the second conductor device (2) and the third conductor device (3), and- a second pivotable pressing clamp (30) is provided, wherein said second pressing clamp (30) has a second clamp shaft (31) and at least one second clamp edge (32) being arranged for applying a contact pressure on the overlapping conductor sections (2A, 3A) of the second conductor device (2) and the third conductor device (3) accommodated by the connector receptacle (10) so that the overlapping conductor sections (2A, 3A) of the second conductor device (2) and the third conductor device (3) directly contact each other, wherein- the base portion (11) provides a support for the first, second and third conductor devices (1, 2, 3) and the bearing portion (12) is arranged for accommodating the first clamp shaft (21) of the first pressing clamp (20) and the second clamp shaft (31) of the second pressing clamp (30), and- the second pressing clamp (30) is adapted for a pivoting motion between a clamp condition, wherein the at least one second clamp edge (32) of the second pressing clamp (30) presses the overlapping conductor sections (2A, 3A) of the second conductor device (2) and the third conductor device (3) against the base portion (11), and a release condition, wherein the at least one second clamp edge (32) of the first pressing clamp (20) releases the overlapping conductor sections (2A, 3A) of the second conductor device (2) and the third conductor device (3).

12. Connector apparatus according to claim 11, wherein- the second pressing clamp (30) is configured like the first pressing clamp (20).

13. Connector apparatus according to one of the foregoing claims, wherein- the connector receptacle (10) is configured for accommodating conductor devices comprising at least one of a superconducting flat cable and a printed circuit board (PCB).

14. Electrical conductor arrangement, including- a first conductor device (1),- a second conductor device (2), and- the connector apparatus (100) according to one of the foregoing claims, wherein- the first and second conductor devices (1, 2) are electrically connected via the connector apparatus (100).

15. Electrical conductor arrangement according to claim 14, including- a third conductor device (3) coupled with the connector apparatus (100), wherein- the second conductor device (2) is arranged in the connector apparatus (100) and the third conductor device (3) is electrically connected with the second conductor device (2).

16. Electrical conductor arrangement according to one of the claims 14 or 15, wherein- each of the first, second and optionally third conductor devices (1, 2, 3) has at least one conductor element having a flat shape at the overlapping conductor section of the conductor device (1, 2, 3).

17. Electrical conductor arrangement according to one of the claims 14 to 16, wherein- materials of the connector apparatus (100) and the first, second and optionally third conductor devices (1, 2, 3) are selected such that an electrically superconducting connection between the conductor devices (1, 2, 3) accommodated by the connector apparatus (100) is obtained at temperatures below 10K, preferably below 2K.

18. Method of using the connector apparatus (100) according to one of the claims 1 to 13, comprising the steps of- arranging a first conductor device (1) and a second conductor device (2) in the connector receptacle (10) such that longitudinal conductor sections (1A, 2A) of the first and second conductor devices (1, 2) overlap each other in the connector receptacle (10),- applying a contact pressure with the first pressing clamp (20) and pressing the first and second conductor devices (1, 2) against each other, so that the overlapping conductor sections (1A, 2A) of the first and second conductor devices (1, 2) directly contact each other in the overlapping portion, and- arranging the first conductor device (1) and the second conductor device (2) connected via the connector apparatus (100) in an environment with a reduced temperature, so that an electrically superconducting connection between the first conductor device (1) and the second conductor device (2) is obtained.

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