Test pin device

Abstract

The invention relates to a test pin (10) for electrically contacting a contact partner (20), in particular a planar surface (21) of a contact partner, comprising: a substantially sleeve-shaped main body (1); a contact head (3), which is arranged on a contact side (2a) of the body (1), which is close to the contact counterpart (20), and which has at least two sections (5a, 5b, 5c, 5d) extending axially from a base (4) of the contact head (3); wherein the sections (5a, 5b, 5c, 5d) each have at least one preferably rigid cutting element (6a, 6b, 6c, 6d) for cutting in and / or scraping a surface of the open contact partner (21), which cutting element extends from an end face of the section in question, and the contact head (3) is designed such that, when a force (F), in particular a compressive force, acting on the test pin (10) in the axial direction is exerted, the cutting element (6a, 6b, 6c, 6d) is cut in and / or scraped by the cutting element (6a, 6b, 6c, 6d). The radial expansion or gathering of the cutting elements (6a, 6b, 6c, 6d) is carried out.

Description

[0001] The invention relates to a test needle for reversibly contacting a contact partner, in particular for making surface contact with an energy storage device.

[0002] Test pins or test pin devices with contact heads are generally known from the prior art and are used in the field of testing or other test contexts to check the function of test counterparts, such as electronic components with suitable socket sections. For this purpose, the test pin device is placed as a plug on the contact counterpart to be tested or contacts the contact counterpart. Subsequently, a test signal is applied to the contact counterpart via suitable contact. A plurality of such test pins can also be provided in a common fastening device for coupling the test pins to corresponding contact counterparts of the test object.

[0003] For example, the general WO2012 / 136562 discloses a test needle, which comprises a sleeve-shaped housing, a sleeve-shaped contact element movably guided therein, and a needle-shaped element interacting with the sleeve-shaped contact element, the latter and the contact element being axially preloaded in a first uncompressed non-contact position by a separate elastic element in the housing. When the contact element is pressed into a socket section to be contacted or tested, an axial force acts on the test needle through a stopper in the form of a collar around the contact element, causing the contact element to be transferred to a second pressed-in contact position, the needle-shaped element being pressed against the inner contact surface of the contact element, causing the radial widening of the contact head to contact the socket section through the circumferential surface of the test needle, i.e. contact the socket section.

[0004] Test devices designed to contact energy storage devices, in particular batteries, are also known. In particular, contact can be made with a planar surface of an energy storage device, in particular at a terminal. For example, DE202018104812U1 discloses a contact module for making electrical touch contact with a component, the contact module comprising a support having a contact side that can be assigned to the component and a connection side facing away from the contact side, wherein at least two conductive contact elements are arranged in the support, in particular in the form of spring contact pins with contact heads that can be pressed in. The second contact pin can be arranged at an angle relative to the contact direction, which means that the contact head in question is displaced laterally along the contact point of the component in question, thereby causing the surface of the contact point to be scratched and thus establishing a firm electrical contact. However, this may result in the undesirable introduction of lateral forces or lateral displacement of the entire test module, resulting in undesirable lateral forces acting on the device suspension device or fastening device.

[0005] Based on the known prior art, the object of the present invention is to provide an improved test pin for contacting an energy storage device, which test pin enables high-quality contacting during the testing process and is at the same time simple to implement in terms of construction and easy to maintain.

[0006] This object is achieved by a device and a test needle according to the independent claims. The dependent claims describe advantageous embodiments of the invention. All combinations of at least two of the features disclosed in the claims, the description and / or the drawings fall within the scope of the invention.

[0007] The present invention relates to a test needle for making electrical touch contact with a contact counterpart, in particular a planar surface of the contact counterpart, the test needle comprising a substantially sleeve-shaped body, a contact head arranged on the contact side of the body facing the contact counterpart, the contact head having at least two sections extending axially from the base of the contact head, wherein each of the sections has at least one preferably rigid cutting element extending from its front end for cutting into and / or scraping the surface of the contact counterpart, and the contact head is configured such that when a force (in particular a compressive force) acting on the test needle in an axial direction is applied, the cutting element radially widens and / or narrows.

[0008] The invention enables simple contacting of surfaces, in particular at the terminals of energy storage device equipment for charging and / or testing purposes. A cutting element arranged at the front can be used to cut a passivated surface of a contact partner, for example an oxide surface of aluminum. This results in a very low contact resistance, which minimizes heating temperatures, in particular when high currents are transmitted. The cutting elements, which are preferably rigidly arranged on the section, enable a very precise introduction of forces for cutting the surface. The radial widening and / or narrowing of at least two cutting elements on the contact partner provides a radial expansion and / or radial contraction of the individual cutting elements, which enables stable and easy contacting. In particular, this can also reduce the axial contact force of the contact element in question and thus reduce the mechanical stress on the energy storage device.

[0009] The application of a force, in particular a compressive force, acting on the test needle in the axial direction occurs in particular when the test needle and the contact counterpart to be contacted are moved towards each other, for example by a test device arranged on the rear side of the test needle, in order to hold the needle. When the test needle or the contact head is in contact with the contact counterpart, an axial force or a compressive force acts on the test needle and in particular also on the contact head. For example, contact can be achieved by axially moving the test needle onto a contact counterpart that is held in place or held in an immovable manner, or vice versa, i.e. by axially moving the contact counterpart onto a contact needle that is held in place.

[0010] In a preferred embodiment, the axially extending segments of the contact head and / or the cutting elements arranged thereon are distributed circumferentially around the center axis of the contact head, preferably evenly distributed. This allows the applied axial forces to be distributed particularly evenly over the segments, in particular minimizing the undesired introduction of lateral forces into the test pin when the cutting elements widen and / or narrow.

[0011] It is further preferred that the axially extending section of the contact head and / or the cutting element arranged thereon are arranged offset radially outwards with respect to a centre axis of the contact head, preferably offset by the same radial distance from the centre axis.

[0012] The segments are further preferably formed by at least one or more preferably groove-shaped recesses on the side of the contact head facing the contact counterpart, each of which extends parallel to the central axis of the contact head. The recesses extend from the side of the contact head facing the contact counterpart (preferably with the same length) to the base of the contact head. Preferably, at least one (especially groove-shaped) recess is provided, which means that the contact head comprises at least two segments extending axially and preferably parallel to each other. In a further preferred embodiment, the contact head comprises two recesses, which are arranged perpendicularly to each other and intersect the central axis of the contact head. As a result, the contact head has four segments, which are preferably parallel to each other.

[0013] Further preferably, the contact head has a central hole, which is coaxial with the central axis of the test needle or the contact head. The central hole can be designed for feedthrough and / or mounting of a sensor element (such as a temperature sensor). The sensor element or the sensor head of the sensor element can preferably extend almost as far as the cutting element or be arranged behind the cutting element in the contact head. Alternatively or additionally, the hole can be designed for feedthrough of an inner conductor for additional or extended contact of a contact counterpart. Alternatively or additionally, the hole can also be designed as a cooling channel for conveying a cooling fluid (in particular cooling air) to the contact counterpart or to the contact point of the contact head and the contact counterpart.

[0014] In another preferred embodiment, the contact head is mounted so that it can at least partially move axially within the sleeve-shaped body and is preloaded by an elastic element. The body preferably has a central, preferably substantially hollow cylindrical guide portion in which the elastic element is arranged and at least a portion of the contact head, in particular the proximal base of the contact head, is mounted in an axially movable manner.

[0015] The contact head is preferably arranged to move axially in the body, so that when in an extended first non-contact position, the contact head is preloaded against a stop element (in particular an annular shoulder) by the elastic element, and when in a second contact position, the contact head is at least partially pressed or pressable into the body against the preload force of the elastic element. The first non-contact position corresponds to a default state of the test needle in which no contact is made with a contact counterpart.

[0016] In a preferred embodiment, the test needle comprises a needle element which is mounted in the body in a preferably immovable manner and which is configured to interact with the contact head in a position-dependent manner so that when the contact head is pressed in the contact position of the test needle, the needle element engages in a central opening portion and in the process radially widens the section of the contact head and the cutting element arranged thereon in a preferably uniform manner. The needle element and the opening portion interacting therewith are preferably coaxial with the central axis of the test needle and the contact head. The opening portion is arranged on the side of the base of the contact head facing the contact counterpart or in a portion of the contact head associated with the section. The opening portion can be a tapered opening or through hole, with the distal portion of the needle element engaging in the opening or through hole and in the process widening the section of the contact head. The needle element preferably comprises a shaft with a constant outer diameter and an at least partially tapered distal portion.

[0017] The needle element is preferably immovably arranged in the central guide portion of the sleeve-shaped body. The elastic element preferably surrounds the needle element. The elastic element can be arranged or preloaded between a first circumferential shoulder of the proximal portion of the needle element and a shoulder arranged at the end of the base of the contact head.

[0018] In a preferred embodiment, the test needle comprises only one elastic element, which is further preferably arranged in a guide section of the sleeve-shaped body.

[0019] In another preferred embodiment, the needle element comprises a contoured portion on its outer circumferential surface and downstream of the distal portion in the axial displacement direction, the contoured portion preferably having a reduced outer diameter. The contoured portion is configured to interact with the contact head in a position-dependent manner so that when the contact head is pressed further in, the contoured portion engages with the central opening portion after the distal portion and, in doing so, causes the segment of the contact head to be radially narrowed in a preferably uniform manner and in the non-contact position of the contact head in the direction of the default position of the segment.

[0020] The opening section of the contact head comprises a tapered section and preferably a radial widening section associated therewith on both sides in the direction of movement. The contact head is configured to interact sequentially with the needle element so that when a contact counterpart is contacted and the contact head is thereby pressed in, the segments or the cutting elements arranged thereon first undergo a preferably uniform radial widening and then, with further pressing in, a preferably uniform radial narrowing. The sequential radial widening and subsequent radial narrowing of the segments or the cutting elements arranged thereon allows a particularly effective contact with the contact counterpart.

[0021] In a preferred alternative embodiment, the contact head is configured to interact, depending on the position, with a distal opening and / or with an inner circumferential surface of a preferably hollow cylindrical guide element arranged on the body, so that when the contact head is pressed in the contact position of the test needle, the opening and / or the inner circumferential surface causes the section of the contact head or the cutting element arranged thereon to be radially narrowed in a preferably uniform manner. The preferably hollow cylindrical guide element can be mounted on the body and / or on the contact head in an axially movable manner by means of a second elastic element, which is preferably an index spring. The second elastic element can be preloaded between a rear annular shoulder of the body and a proximal end face of the guide element. In addition, in the non-contact position, the guide element can be preloaded against an annular shoulder arranged on the body.

[0022] If the second elastic element is an exponential spring or a spring having an exponential spring force when compressed, the contact force applied to the contact partner can first be increased so that the cutting element can preferably penetrate the surface to be contacted vertically before the radial force acts on the cutting element, causing the surface to be cut and / or scraped by the cutting element.

[0023] In another alternative embodiment, the contact head may be integrally formed on the contact side of the body. In this case, the segments and associated cutting elements are arranged so that the axial contact force on the test pin results in a preferably uniform widening or narrowing of the cutting element. In this case, the cutting element preferably has a cutting edge or edge shape that is angled relative to the surface to be contacted. The cutting edges or cutting edge shapes are arranged radially in an axial top view, which means that the axial contact pressure of each cutting element results in a radial bending or widening of the cutting element relative to the central axis of the contact head.

[0024] The corresponding cutting elements of the contact head are configured to at least partially cut into and / or scrape the preferably planar surface and / or passivated surface of the contact counterpart. In the axial top view, each cutting element comprises a cutting edge or a cutting edge shape extending radially outward. Alternatively or additionally, the cutting element can have other cutting edge shapes, in particular a circumferential tangential cutting edge or a cutting edge shape in the axial top view. This means that the cutting edge or the cutting edge shape is substantially linear and, in the axial top view of the contact head, is tangent to a circle coaxial with the center axis or perpendicular to a predefined radius. The respective cutting edges of the corresponding cutting elements of the contact head are preferably tangent to the same circle or are arranged at the same radial distance from the center axis.

[0025] Each section of the contact head can also have a plurality of cutting elements. They can have similar designs or different designs.

[0026] The description, advantages and details of the invention are explained below with reference to the purely schematic, merely exemplary drawings.

[0027] Figure 1a is a side view of a first preferred embodiment of a test needle according to the present invention; Figure 1b-Figure 1d In different locations Figure 1a A cross-sectional view of a test pin; Figure 2a is a cross-sectional side view of a variation of the previous embodiment of the test needle according to the present invention; Figure 2b Shows the contact position Figure 2a Test pin; Figure 3a-3e is a cross-sectional side view of a second preferred embodiment of a test pin; Figure 4a , Figure 4b are different views of a variation of the previous embodiment of the test needle according to the present invention; Figure 5a-5e are different views of a third preferred embodiment of a test pin; Figure 6a-6b is a different view of another preferred contact head configuration; Figure 7a – Figure 7b are different views of other preferred contact head configurations; Figure 8a-8b are different views of other preferred contact head configurations; and Figure 9a – Figure 9b Another preferred contact head configuration is shown.

[0028] Figure 1a to Figure 1dA first preferred embodiment of a test pin 10 according to the invention is shown, which is used for making an electrical touch contact with, in particular, a planar surface 21 of a contact counterpart 20 , such as a terminal of an energy storage device.

[0029] The test pin has a substantially sleeve-shaped body 1 with a contact side 2a facing the contact counterpart 20 and an opposite connection side 2b facing away from the contact counterpart. The test pin also comprises a contact head 3 arranged on the contact side and having a base 4 on the rear side (i.e. the side facing away from the contact counterpart 20) and sections 5a, 5b extending from the base 4 towards the contact counterpart 20.

[0030] The contact head 3 is guided by the base 4 in an at least partially axially movable manner and is mounted in a central guide part 17 of the test needle. The guide part 17 has an elastic element 11 which preloads the contact head 3 to the central guide part 17. Figure 1a and Figure 1b The non-contact position of the test pin 10 is shown in FIG. The elastic element 11 may be the only elastic element of the test pin 10 and is arranged between a rear stop in the guide portion 17 and an opposite end face of the contact head 3 facing away from the contact counterpart 20. The elastic element 11 presses the base 4 of the contact head 3 against a stop 12 arranged on the contact side 2a.

[0031] The contact head 3 comprises at least two segments 5a, 5b, which extend axially from the base 4 of the contact head and each segment has a cutting element 6a, 6b, which extends from one end of the segment and is preferably rigid (i.e., immovable relative to the segment 5a, 5b). The cutting elements 6a, 6b are preferably formed integrally (i.e., in one piece) with the associated segment 5a, 5b, respectively. The cutting elements 6a, 6b are configured to cut into and / or scrape the surface 21 of the contact counterpart 20, which surface is in particular a so-called passivation surface, which is produced by oxidation.

[0032] The contact head is configured so that when a force F acting on the test needle 10 in the axial direction is applied, the cutting elements widen and / or narrow radially. In an axial top view of the test needle, at least two sections 5a, 5b and the cutting elements 6a, 6b arranged thereon widen (i.e., extend radially outward) or narrow radially inward. In this context, "radial" means that, in an axial top view, the widening or narrowing of the individual elements occurs in a radial direction from the center axis of the contact head. The radial widening or narrowing of the cutting elements allows them to move, starting from an initial contact position on the contact counterpart, along the surface of the contact counterpart or substantially parallel to the surface and, in the process, cut into and scrape the surface.

[0033] Figure 1bA cross-sectional view in an extended first non-contact position is shown. The test needle has a central axial hole 8 arranged in the contact head 3 and extending through the entire contact head 3. In the non-contact position, a needle element 13, preferably mounted immovably in the body 1, at least partially engages the hole 8. The needle element 13 is preferably made of a solid material. Alternatively, the needle element 13 itself can also have a through hole, in which a sensor or other component such as an inner conductor 9 (see Figure 1d ). In addition, such a through hole can also provide a cooling channel for conveying a cooling fluid, in particular, cooling air.

[0034] The needle element 13 is configured to interact with the contact head 3 depending on the position. In particular, during the pressing of the contact head 3 into the body 1, the distal portion 13a of the needle element 13 engages with the central opening portion 14 of the hole 8. This can be in particular a tapered portion of the hole 8, preferably a continuous tapered portion in the direction of movement of the needle element 13 during the pressing. When the needle element 13 engages with the opening portion 14, the segments 5a, 5b of the contact head 3 are thus stretched apart, as shown in FIG. Figure 1c exemplified in .

[0035] When the test needle 10 is in contact with the contact counterpart 20, the sections 5a, 5b with the cutting elements 6a, 6b arranged at the ends are initially placed on the contact counterpart 20, and then, under a continuous axial contact pressure, through the interaction between the needle element 13 and the opening portion 14, as the contact force F increases, the respective cutting elements 6a, 6b move in parallel to the surface 21 on the contact counterpart 20 or move in a radial or lateral direction at the same time (see Figure 1c ); When the contact pressure is released (ie, when the test needle 10 moves in the direction opposite to the pressure), the spring force of the elastic element 11 causes it to return to Figure 1a , Figure 1b The non-contact position shown in .

[0036] Figure 2a , Figure 2b The test needle described above is shown with a modified construction of the needle element 13 and the opening portion 14. They are now designed so that the sections 5a, 5b are stretched and narrowed sequentially on the surface 21 of the contact counterpart 20 when the test needle 10 is transferred from the non-contact position to the contact position. In this case, the needle element 13 is wavy and in particular has a wavy section 13b with a reduced outer diameter, which is located downstream of the distal section 13a in the axial movement direction. When the contact head 3 is pressed in, the distal section 13a is first introduced into the opening section 14 of the through hole 8 with a reduced diameter, resulting in the widening of the sections described above. During further pressing in, the wavy section 13b interacts with the opening section 14, and the reduced outer diameter causes the sections 5a, 5b to close or narrow again.

[0037] Figures 3a to 3e Another preferred embodiment of the test needle 10 is shown, which has a hollow cylindrical guide element 14 mounted on the body 1 and / or the contact head 3 in an axially movable manner instead of the needle element 13. The example shown has a plurality of segments 5a, ..., 5n, each segment having a cutting element 6a, ..., 6n. At the circumference, the segments 5a, ..., 5n are surrounded or retained by the guide element 14. The guide element 14 is preloaded in the direction of the non-contact position from the body by the second elastic element 1, and the guide element 14 is pushed against a stopper 15a provided on the body 1. Similar to the previous embodiment, each segment 5a, ..., 5n is an axially extending element extending from the common base 4 of the contact head 3.

[0038] The contact head 3 is designed to interact with the distal opening 14a and / or with the inner circumferential surface 14b of the hollow cylindrical guide element 14, depending on the position, so that the opening 14a and / or the inner circumferential surface 14b of the segments 5a, ..., 5n of the contact head 3 are radially narrowed in a preferably uniform manner when the contact head is pressed in. The individual segments 5a, ..., 5n can each have an outer surface or circumferential surface 18, which widens toward the contact counterpart and is mounted in the corresponding inner circumferential surface 14b, which preferably widens at least partially conically outwardly.

[0039] Figure 3d and Figure 3e Two slightly modified embodiments are shown for a possible contact head 3 which differ in the number of segments 5a, ..., 5n with cutting elements 6a, ..., 6n. Figure 3e An embodiment of has two sections without cutting elements between corresponding sections with cutting elements.

[0040] The axially extending sections 5a, ..., 5n of the contact head 3 and / or the cutting elements 6a, ..., 6n arranged thereon are arranged radially offset outwardly relative to the center axis M of the contact head 3, preferably offset from the center axis M by the same radial distance r1 (see also Figure 3c ).

[0041] The segments 5a, ..., 5n are evenly distributed circumferentially. Preferably, the cutting elements 6a, ..., 6n associated with the respective segments are also evenly distributed circumferentially. The respective cutting elements 6a, ..., 6n form a preferably substantially annular contact surface of the respective cutting element on the surface 21 to be contacted. According to the invention, the diameter of the annular contact surface is continuously reduced by radial narrowing of the cutting elements 6a, ..., 6n.

[0042] Figure 4a , Figure 4b A modified test needle according to the previous embodiment is shown, in which the hollow cylindrical guide element 14 has a smaller longitudinal extension and, in particular, only surrounds the distal end portion 19 of the contact head 3; similar to the previously described embodiments, in which the guide segments 5a, 5b, 5c, 5d also have an outer surface or circumferential surface 18, which widens towards the contact counterpart and which is mounted in a corresponding inner circumferential surface 14b, which preferably widens conically at least partially outwards.

[0043] The sections 5a, 5b, 5c, 5d are formed by two groove-like recesses 7a, 7b on the side of the contact head 3 facing the contact counterpart 20, the recesses 7a, 7b are each arranged parallel to the center axis M of the contact head 3 and intersect vertically therein. When viewed from above, the sections 5a, 5b, 5c, 5d each have the shape of a sector of a circle with a center hole 8.

[0044] The second elastic element 15 is preferably an index spring, which is mounted in an axially movable manner on the body 1 and / or the contact head 3. In particular, the elastic element is preloaded between the rear annular shoulder 22a of the body and the proximal annular shoulder 22b of the guide element 14. If the second elastic element is an index spring, the contact force applied to the contact partner when contacting the contact partner can first increase, so that the cutting element can penetrate the surface to be contacted before the radial force acts on the cutting element, thereby causing the cutting element to cut and / or scrape the surface.

[0045] Figure 5a to Figure 5e Another preferred embodiment is shown, in which the contact head 3 is integrally formed on the contact side 2a of the body 1 or is rigidly (i.e. immovably) connected thereto. The segments 5a, ..., 5n and the associated cutting elements 6a, ..., 6b are arranged such that the axial contact forces on the test pin 10 lead to a preferably uniform widening of the cutting elements. The segments are preferably formed by essentially triangular recesses in the sleeve-shaped circumferential surface of the contact head 3; The cutting elements each preferably have a cutting edge 23 angled relative to the surface to be contacted. The cutting edge 23 shape is preferably arranged substantially radially in an axial top view, so that the axial contact pressure of each cutting element causes a radial bending or widening of each cutting element relative to the central axis M of the contact head 3.

[0046] The temperature sensor 24 may be arranged in a stop sleeve 25 surrounding it, and the temperature sensor 24 may be disposed in the central hole 8 of the body 1 . Figure 5eAn embodiment is shown without a temperature sensor 24 arranged therein. Alternatively or additionally, for example, an inner conductor for voltage measurement can be accommodated in the hole 8 as a sensor element. The inner conductor can be, for example, a known spring-loaded contact pin. Additionally or alternatively, the hole 8 can provide a cooling channel through which cooling air can be conveyed, in particular as a cooling fluid, to the contact point of the contact head and the contact counterpart.

[0047] Figure 6a Various configurations of a contact head 3 are shown, which has four circular segment-shaped sections 5a, 5b, 5c, 5d extending axially from a base 4, wherein the corresponding bases 4, 4', 4" in the figures shown may be designed differently in length and / or configuration. A larger axial length of the base 4 may result in improved signal or current transmission.

[0048] like Figure 6b As shown in the figure, the segments 5a, 5b, 5c, 5d can each have two or more cutting elements 6a, 6a', 6a", which are, for example, circumferentially tangential to the annular contact surface of the cutting element on the surface of the contact counterpart 20. The cutting elements arranged in this way lead to scraping or scraping the surface to be contacted in an annular extension.

[0049] Figure 7a and Figure 7b 2 shows further possible embodiments of the respective contact head 3 for the test pin. The respective cutting elements 6a, ..., 6n may be groove-shaped elements 26, such as Figure 7b Alternatively, the cutting elements 6a, ..., 6n may also be point-shaped or pyramid-shaped, such as Figure 7a and Figure 7b Such point-shaped or pyramid-shaped elements can be arranged only in the circumferential region of the end face 28 of the contact head 3 or can be evenly distributed over the entire end face.

[0050] Figure 8a , Figure 8b and Figure 9a , Figure 9b Some other possible embodiments of the contact head 3 according to the present invention are shown, each of which has a radial direction ( Figure 8b right; Figure 9b ) or tangential ( Figure 8b Left) cutting edge 23, or having a cutting edge 23 oriented perpendicular to the radial direction.

[0051] Reference numerals 1 Main body 2a Contact side 2b Connection side 3 Contact head 4 Base of the contact Sections 5a, ..., 5n 6a, ..., 6n Cutting element 7a, 7b concave portion 8 Center hole 9 Sensor element / inner conductor 10 Test pin 11 Elastic element 12 Stop element 13-pin element 13a Distal part 13b Contoured section 14 Guide element 14a Distal opening 14b Inner circumferential surface 15. Second elastic element 15a Stopper of guide element 16a, 16b Radial tangential cutting edge 17 Center guide part body 18 External surface 19 Contact end portion 20 Contact mating parts 21 Surface contact counterpart 22a Annular shoulder body 22b Annular shoulder guide element 23 Cutting Edge 24 Temperature sensor / inner conductor 25 Stop sleeve 26 Groove-shaped structure 27 Pointed structure 28 End face of contact head M Center axis r1 Radial distance F Axial force / compression force

Claims

1. A test needle (10) for making electrical contact with a contact counterpart (20), in particular a planar surface (21) of the contact counterpart, the test needle (10) comprising: A substantially sleeve-shaped body (1); A contact head (3), the contact head (3) being arranged on a contact side (2a) of the body (1) facing the contact counterpart (20), the contact head (3) having at least two sections (5a, 5b, 5c, 5d) extending axially from a base (4) of the contact head (3), It is characterized in that The sections (5a, 5b, 5c, 5d) each have at least one preferably rigid cutting element (6a, 6b, 6c, 6d) extending from their front ends for cutting into and / or scraping the surface (21) of the contact counterpart (20), and the contact head (3) is configured such that, when a force (F) acting on the test needle (10) in the axial direction is applied, the cutting element (6a, 6b, 6c, 6d) radially widens and / or narrows.

2. The test needle according to claim 1, characterized in that: The axially extending sections (5a, 5b, 5c, 5d) of the contact head and / or the cutting elements (6a, 6b, 6c, 6d) arranged thereon are distributed circumferentially around a central axis (M) of the contact head (3), preferably evenly distributed.

3. The test needle according to claim 1 or 2, characterized in that: The axially extending sections (5a, 5b, 5c, 5d) of the contact head (3) and / or the cutting elements (6a, 6b, 6c, 6d) arranged thereon are arranged to be radially offset outwardly relative to a center axis (M) of the contact head (3), preferably offset from the center axis (M) by the same radial distance (r1).

4. A test needle according to any one of the preceding claims, characterized in that The sections (5a, 5b, 5c, 5d) are formed by at least one or more preferably groove-shaped recesses (7a, 7b) on the side of the contact head (3) facing the contact counterpart (20), the recesses (7a, 7b) each extending parallel to a center axis (M) of the contact head (3).

5. A test needle according to any one of the preceding claims, characterized in that The contact head (3) has a central hole (8), which is coaxial with the central axis (M) of the test pin (10) and accommodates a sensor element (9) or an inner conductor for contacting the contact counterpart (20) in the central hole (8), the sensor element being in particular a temperature sensor, and / or the central hole (8) providing a cooling channel for conveying a cooling fluid, in particular cooling air.

6. A test needle according to any one of the preceding claims, characterized in that The contact head (3) is mounted such that it can at least partially move axially within the sleeve-shaped body (1) and is preloaded by an elastic element (11).

7. A test needle according to any one of the preceding claims, characterized in that The contact head (3) is arranged to move axially in the body (1) so that when in the extended first non-contact position, the contact head is preloaded against a stop element (12) by the elastic element (11), the stop element being in particular an annular shoulder, and when in the second contact position, the contact head is at least partially pressed into the body (1) against the preload force of the elastic element (11).

8. A test needle according to any one of the preceding claims, characterized in that The body (1) has a needle element (13) which is mounted in the body (1) in a preferably non-movable manner and is configured to interact with the contact head (3) in a position-dependent manner so that when the contact head (3) is pressed into the contact position of the test needle (10), the needle element (13) engages in a central opening portion (14) and thereby radially widens the sections (5a, 5b, 5c, 5d) of the contact head (3) in a preferably uniform manner.

9. The test needle according to claim 8, characterized in that: The needle element (13) has a corrugated portion (13b) on its outer circumferential surface and downstream of the distal portion (13a) in the axial movement direction, the corrugated portion (13b) preferably having a reduced outer diameter and being configured to interact with the contact head (3) depending on the position, so that when the contact head (3) is pressed further in, the corrugated portion (13b) engages with the central opening portion (14) behind the distal portion (13a) and in the process radially narrows the sections (5a, 5b, 5c, 5d) of the contact head (3) in a preferably uniform manner.

10. The test needle according to claim 8 or 9, characterized in that: The sleeve-shaped body (1) has a central guide section (17) in which the needle element (13) and, surrounding the needle element (13), a preferably single elastic element (11) of the test needle (10) extend axially.

11. The test needle according to any one of claims 1 to 7, characterized in that: The contact head (3) is designed to interact, depending on the position, with a distal opening (14a) and / or with an inner circumferential surface (14b) of a preferably hollow cylindrical guide element (14) arranged on the body (1) so that when the contact head (3) is pressed into the contact position of the test needle (10), the opening (14a) and / or the inner circumferential surface (14b) cause the sections (5a, 5b, 5c, 5d) of the contact head (3) to be radially narrowed in a preferably uniform manner.

12. The test needle according to claim 11, characterized in that: The preferably hollow-cylindrical guide element (14) is mounted on the body (1) and / or on the contact head (3) in an axially movable manner by means of a second elastic element (15), which is preferably an exponential spring.

13. The test needle according to any one of claims 1 to 5, characterized in that: The contact head (3) is integrally formed on the contact side (2a) of the main body (1).

14. A test needle according to any one of the preceding claims, characterized in that The cutting element (6a, 6b, 6c, 6d) of the contact head (3) is configured to at least partially cut into and / or scrape a preferably planar surface and / or a passivated surface (21) of the contact counterpart (20).

15. A test needle according to any one of the preceding claims, characterized in that The cutting elements (6a, 6b, 6c, 6d) each have a cutting edge (16a) extending radially outward in an axial top view and / or a cutting edge (16b) arranged tangentially at the circumference.

16. A test needle according to any one of the preceding claims, characterized in that Each section (5a, 5b, 5c, 5d) of the contact head (3) has a plurality of cutting elements.

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