WO2025083166A1

WO2025083166A1 - Spring-loaded contact

Info

Publication number: WO2025083166A1
Application number: PCT/EP2024/079411
Authority: WO
Inventors: Tanguy Tronel; Clément BIDAULT; Didier Guélat; Matthew Wilhite
Original assignee: Preci-Dip Sa
Priority date: 2023-10-17
Filing date: 2024-10-17
Publication date: 2025-04-24

Abstract

A spring-loaded contact including: • A hollow body, • A coil spring received at least partially in the hollow body, • A pin body comprising: - A base portion adapted to be electrically connected with an external part, - A pin portion comprising at least two beams extending from the base portion and contacting the hollow body, each beam including a distal part distal from the base portion, wherein the distal part of at least one beam applies a force on the coil spring.

Description

SP RI NG-LOAD ED CONTACT

[0001 ] The present disclosure relates to a spring-loaded contact including a pin body and methods to manufacture a pin body and the spring-loaded contact.

BACKGROUND

[0002] Spring-loaded contacts, also referred to as pogo pins, are integral components in an array of technical fields subjected to significant constraints, including the aerospace, automotive, space, and military industries. These domains necessitate the implementation of reliable and durable electrical connections to maintain the proper functioning of complex systems and ensure the safety of their users. The spring-loaded contact, which generally incorporates a plunger, a barrel, and a spring, provides such a reliable electrical connection, facilitating the transmission of signals and power between two mating surfaces. The inherent mechanical compliance of these contacts allows for a degree of misalignment and movement between connected components, thereby ensuring a stable connection even in the face of environmental factors such as vibrations and thermal expansion.

[0003] In addition to their compactness and reliability, spring-loaded contacts may endure the rigorous operating conditions encountered in industries such as automotive and military applications. These contacts must withstand a wide range of environmental conditions, including temperature extremes, humidity, corrosion, and exposure to various chemicals. The robustness of spring-loaded contacts should ensure a long-lasting electrical connection, minimizing the risk of system failure and reducing the need for frequent maintenance or replacement. The resilience of these contacts should enhance the overall reliability and longevity of the systems in which they are employed, ultimately contributing to the safety and dependability of vehicles, aircraft, spacecraft, and military equipment.

[0004] As miniaturization trends continue to pervade various technical fields, the demand for low-profile electrical connections has surged. Although the compact design of spring-loaded contact enables them to accommodate space constraints without compromising the integrity of the electrical connection, there is still a need to propose spring-loaded contact having a low-profile, i.e. a limited height while providing an extended spring stroke to support severe mechanical constraints. A reduced-height contact is thus needed for streamlined and space-efficient designs in industries such as aviation and space exploration, where every millimetre counts. Furthermore, a low-profile contact minimizes the risk of mechanical interference, ensuring the uninterrupted operation of intricate electronic systems in these demanding environments.

[0005] Cost reduction is a crucial consideration across all technical fields, and the implementation of spring-loaded contacts can contribute to achieving this objective. By providing reliable and long-lasting electrical connections, these contacts reduce the need for frequent repairs and replacements, thereby minimizing associated costs. Additionally, the use of low-profile contacts allows for more efficient designs that require fewer materials and resources, leading to further cost savings. However, low-profile spring-loaded contact may be difficult to manufacture and assemble.

SUMMARY

[0006] An object of the disclosure is to provide a reliable spring-loaded contact having a long stroke, a small diameter and adapted to high-power applications. The document WO2022/223474 discloses a piston assembly and a springloaded contact having a low profile. However, this spring-loaded contact requires a minimal width or diameter to ensure a sufficient coil spring force. In addition, this spring-loaded contact requires an open end, which is to be avoided for applications in which foreign material may penetrate the springloaded contact. Finally, this prior art spring-loaded contact may show a stark increase in temperature when a high current is circulated and is not adapted to high-power applications.

[0007] The present disclosure concerns a spring-loaded contact including: • A hollow body,

• A coil spring received at least partially in the hollow body,

• A pin body comprising:

- A base portion adapted to be electrically connected with an external part,

- A pin portion comprising at least two beams extending from the base portion and contacting the hollow body, each beam including or defining a distal part of the pin portion, distal from the base portion, wherein the distal part of at least one beam applies a force on the coil spring.

[0008] For example, the force may be applied on the coil spring by one beam only, by half of the beams or by all the beams. The force may be applied directly or indirectly through a movable insert. Preferably, no other element of the pin body applies a force on the coil spring. The pin portion can move in at least part of the hollow body, preferably along a longitudinal axis of the hollow body. For example, the pin portion may be arranged slidably into the hollow body, i.e. in a cavity formed by the hollow body. An electrical connection may be performed directly or indirectly between the base portion and the external part. The pin body and/or the hollow body may be adapted to be received at least partially in a case.

[0009] Due to the specific arrangement of the coil spring with regard to the hollow body and the pin body, a small diameter spring-loaded contact may be obtained, which may allow providing several spring-loaded contacts in a limited area. In addition, the height of the spring-loaded contact may be limited, while the spring-loaded contact may prevent any ingress of foreign material. Finally, a high current or a signal may be reliably transmitted by the spring-loaded contact.

[0010] Advantageously, the distal part of the at least one beam is in contact with the coil spring. For example, a distal part of the at least one beam such as a beam extremity may contact the coil spring, for example through a curved or flat portion. This allows to limit the height of the spring-loaded contact, for applications in which the height should be kept small.

[0011 ] Advantageously, the spring-loaded contact includes a movable insert in contact with the distal part of the at least one beam and with the coil spring, wherein the distal part of the at least one beam applies a force on the coil spring through the movable insert. The movable insert may thus contact the coil spring on one face or along one direction and the pin body on the opposite face or along the opposite direction. This may allow to ensure a reliable positioning of the coil spring with regard to the pin body, in particular for very small diameter spring-loaded contact.

[0012] Advantageously, the pin body is made in one piece, which allows a better electrical connection by the limitation of an internal resistance.

[0013] Advantageously, the beams of the pin portion define a spring effect in a radial or outer direction of the pin portion, i.e. toward an outer direction of the pin body, preferably radially from a longitudinal axis of the pin body. In other words, the beams may apply a force radially, for example on an inner surface of the hollow body and may allow an elastic deformation. For example, this force is 0.3 N to 3 N, preferably 0.5 N to 2 N, at most preferably around 1 N for each beam. This contributes to a continuous electrical contact within the spring-loaded contact, even in the case of a misalignment and/or a tilt movement of the pin body with regard to the hollow body.

[0014] Advantageously, the distal part of the pin portion comprises a contact surface, the contact surface being adapted to contact the hollow body and having preferably a cylindrical cross-section, for example measured on a plane transversal to the longitudinal axis of the pin portion. In other words, the contact surface may be a surface defined by a constant diameter or radius of curvature, i.e. a linear longitudinal section along a plane including the longitudinal axis of the pin body. Such a contact surface allows transmitting important currents, such as 20 A or more. [0015] Advantageously, the distal part has a convex external surface. Such a convex external surface allows ensuring a fixed contact point despite a relative movement of the pin portion with regard to the hollow body.

[0016] Advantageously, the pin portion comprises a central lumen, preferably defining an increasing diameter or width from a closed end inside the pin portion to an open end at the opposite extremity of the pin portion. An internal diameter of the central lumen in the distal portion may thus be greater than that in the internal diameter of the intermediate portion. The lumen contributes to the flexibility of the beams and simplifies the manufacturing of the pin portion.

[0017] Advantageously, each beam includes an intermediate part of the pin portion, located between the distal part and the base portion, wherein the intermediate part has an intermediate cross-section and the distal part has a distal cross-section, and a perimeter enclosing the distal cross-section is larger than a perimeter enclosing the intermediate cross-section. This allows a reliable connection with the hollow body while limiting a diameter of the springloaded contact.

[0018] Advantageously, an area of the distal cross-section is larger than an area of the intermediate cross-section. This may allow optimizing the spring effect of the beams and ensuring a reliable contact with the hollow body.

[0019] Preferably, the at least two beams have each a first thickness close to the base portion and a second thickness distant from the base portion, the second thickness being larger than the first thickness. For example, a ratio between the second thickness and the first thickness of 1.25 to 4, preferably 1 .5 to 3, again preferably 2. The second thickness may be the largest thickness and the first thickness may be the smallest thickness of the beam.

[0020] Preferably, the at least two beams each have a flexible part, the flexible part having the smallest second moment of area of each beam. For example, the flexible part is located between a base part of each beam and an extremity of each beam such as in the intermediate part. For example, a ratio between a second moment of area at a contact surface of each beam and the second moment of area of the flexible part may be 5 to 15, preferably 8 to 12, at most preferably about 10, the contact surface being the surface of the pin portion intended to be in contact with the hollow body, preferably in the distal part.

[0021 ] Advantageously, the beams are separated by at least two grooves, the grooves having a width in the distal part larger than that in the intermediate part. The grooves may contribute to the spring effect and thus to the reliability of the electrical connection. Preferably, the grooves have a limited width with regard to the beams, for example 30% or less, preferably 20% or less, again preferably 10% or less. The grooves may be cutouts provided in the pin portion. At the contact surface, i.e. in the distal part, the grooves may form a cylindrical cross-section with the beams in the case of a cylindrical pin portion.

[0022] Advantageously, the intermediate part has a concave external surface. Such a concave external surface allows providing flexibility and ensure a reliable elastic deformation of the beams.

[0023] Advantageously, the hollow body has an open extremity through which the pin body is at least partially received in the hollow body and a base inner wall or transversal wall opposite to the open extremity, wherein the coil spring is in contact with the base inner wall. Such an arrangement allows a reliable relative movement of the hollow body with regard to the pin body.

[0024] Advantageously, the spring-loaded contact comprises another pin body, the hollow body having an open extremity through which the pin body is at least partially received in the hollow body, and another open extremity through which the another pin body is at least partially received in the hollow body. The open extremities are preferably aligned along a longitudinal axis of the spring-loaded contact. Such a spring-loaded contact may be adapted to shock or vibration intensive applications.

[0025] Preferably, the pin portion comprises a proximal part, located between the intermediate part and the base portion. This proximal part may be integral, i.e. made in one piece, with the intermediate part and the distal part and preferably integral with the base portion. The proximal part may have a constant width or diameter along the longitudinal axis of the pin portion, for example be cylindrical. The proximal part of the pin portion may include a beam base part or may not include any beam. This proximal part may contribute to simplifying manufacturing of the pin portion and/or increasing the length of the stroke of the spring-loaded contact.

[0026] Preferably, the spring-loaded contact comprises a case accommodating at least part of the pin body and the hollow body. The coil spring may be fully accommodated in the case and/or in the hollow body. The case may be metallic or in an insulating material such as a plastic, a polymer or a composite.

[0027] The present disclosure further relates to an electrical or electronic system comprising at least one spring-loaded contact as disclosed above.

[0028] The disclosure further relates to the use of a spring-loaded contact according to any of the above aspects in order to transmit electrical power or electrical signals in an electrical system or electronic system.

[0029] The present disclosure further relates to a method to obtain a pin body as described above, comprising the steps of: a. Screw machining the base portion and the pin portion, b. Obtaining the beams of the pin portion to obtain a first diameter of the distal part, c. Spreading the beams one from the other to obtain a second diameter of the distal part larger than the first diameter.

[0030] For example, the beams may be obtained by screw machining a central lumen in the pin portion and then cutting at least one groove along the longitudinal axis of the pin portion. This manufacturing method allows obtaining the pin body with a limited cost and with low manufacturing tolerances. Other manufacturing methods may be contemplated, for example by additive manufacturing.

[0031 ] Advantageously, the method comprises a step of: d. Calibrating the beams to obtain a third diameter of the distal part smaller than the second diameter and larger than the first diameter.

[0032] The present disclosure further relates to a pin body obtained by the above method and/or adapted to be used or mounted in a spring-loaded contact as defined above.

DESCRIPTION OF THE DRAWINGS

[0033] Other features and advantages of the present disclosure will appear more clearly from the following detailed description of particular non-limiting examples of the disclosure, illustrated by the appended drawings where:

[0034] Figure 1 is an exploded side view of a spring-loaded contact, according to an embodiment of the disclosure.

[0035] Figure 2 represents a side view of a pin portion adapted to be used in the spring-loaded contact, according to figure 1 .

[0036] Figure 3 represents a side view of a pin body of the spring-loaded contact of figure 1 .

[0037] Figure 4 represents a longitudinal-section side view of the spring-loaded contact of figure 1 in an assembled configuration.

[0038] Figure 5A represents an exploded side view of a spring-loaded contact, according to another embodiment of the disclosure.

[0039] Figure 5B represents a longitudinal-section side view of the springloaded contact of figure 5A in an assembled configuration.

[0040] Figure 6A represents an exploded side view of a spring-loaded contact, according to another embodiment of the disclosure.

[0041 ] Figure 6B represents a longitudinal-section side view of the springloaded contact of figure 6A in an assembled configuration. [0042] Figure 7 shows a schematic method of manufacturing a pin body according an embodiment of the disclosure.

DETAILED DESCRIPTION

[0043] The spring-loaded contact is intended to transmit power and/or signal in any electrical or electronic equipment, in particular in the fields of automotive, space, aeronautics or military.

[0044] With reference to Fig. 1 , a spring-loaded contact 1000 according to the disclosure includes a pin body 100, a hollow body 200, a coil spring 300 and a case 400. In an assembled configuration, these elements are fully or substantially aligned on a longitudinal axis A-A’. The pin body 100 includes a base portion 110 and a pin portion 120 extending from the base portion 110. The pin portion 120 is intended to be in contact with the coil spring 300 and with the inner surface of the hollow body 200, in an assembled configuration (see Fig. 3). The pin body 100 is preferably made in one piece.

[0045] With reference to Fig. 2, the pin portion 120 includes a proximal part 120A and optionally an intermediate part 120B and a distal part 120C. The proximal part 120A is the closest from the base portion 110 (not shown in Fig. 2) whereas the distal part 120C is the most distant part from the base portion 110 and may comprise an extremity of the pin body 100 opposite to another extremity defined by the base portion 110. Alternatively, the pin portion 120 may not include any proximal part 120A and the intermediate part 120B may extend directly from the base portion 110 (not shown).

[0046] The pin portion 120 includes at least two beams 121 (see Fig. 1 ) and preferably four beams 121 as visible in Fig. 2. Six or eight beams may also be considered. The beams 121 are somehow aligned with the longitudinal axis of the pin body 100 (i.e. the longitudinal axis A-A’) and are intended to apply a force on the coil spring 300. The beams 121 each comprise a beam base part 121 B toward the base portion 110 and for example protruding from the proximal part 120A, and a beam extremity 121 E opposite to the beam base part 121 B. [0047] The beams 121 are separated one from the others by at least two grooves and preferably four grooves 122 as visible in Fig. 2. The number of grooves 122 can be equal to the number of beams 121 or to half the number of the beams 121 . The width or arc length of each groove is smaller with regard to that of a beam 121 . For example, the width or arc length of each groove is identical and may be 30% or less, preferably 20% or less, again preferably 10% or less of that of a beam on a given cross-section of the pin portion. The grooves 122 may be cutouts separating the beams 121.

[0048] The grooves 122 have preferably an increasing width or arc length along the pin portion 120, from the beam base part i 21 B toward the beam extremity 121 E, for example continuously increasing along the longitudinal axis A-A’ toward the beam extremities 122E. In other words, a width or arc length of a groove 122 is larger in the distal part 120C than in the intermediate part 120B of the pin portion 120. The larger width or arc length of the grooves 122 may be defined between the beam extremities 121 E.

[0049] A central lumen 125 is defined within the beams 121 and communicates with the grooves 122. The central lumen 125 may have an opening on the beam extremity 121 E and a closed end, for example within the intermediate part 120B or preferably within the proximal part 120A. The length of the central lumen 125 on the longitudinal axis A-A’ may be equal or larger with regard to the length of the grooves 122 and of the beams 121.

[0050] The central lumen 125 may be a cylinder, for example with a circular cross-section. Preferably, the central lumen 125 is a frustum with a diameter increasing from the closed end to the open end of the central lumen 125, for example continuously as visible in Fig. 2. In other words, the internal diameter of the central lumen 125 may be smaller in the proximal part 120A and/or in intermediate part 120B with regard to that in the distal part 120C.

[0051 ] The beams 121 may extend from the proximal part 120A or from the intermediate part 120B of the pin portion 120 and may define the distal part 120C and at least part of the intermediate part 120B. In the example of Fig. 2, the beam base parts 121 B are located in the intermediate part 120B of the pin portion 120. Alternatively, the beams 121 may also include the proximal part 120A and/or may protrude directly from the base portion 110. The beam extremity 121 E of each of the beams 121 may define a curved surface or, preferably, a flat surface along a plan perpendicular to the longitudinal axis A- A’, as visible in Fig. 2.

[0052] The intermediate part 120B defines an intermediate cross-section, i.e. a cross-section of one or all the beams in the intermediate part, and the distal part 120C defines a distal cross-section, i.e. a cross-section of one or all the beams in the distal part. The cross-section is for example along a plan perpendicular to the longitudinal axis A-A’. A perimeter enclosing the distal cross-section may be larger than a perimeter enclosing the intermediate crosssection. The area of the intermediate cross-section may be smaller than an area of the distal cross-section. The distal cross-section may be the largest cross-section of the pin portion and the intermediate cross-section may be the smallest cross-section of the pin portion. A ratio of the distal cross-section with regard to the intermediate cross-section is 2 to 6, preferably 3 to 5, at most preferably 4.

[0053] A thickness, width, arc length and/or outer diameter of the pin portion 120 in the intermediate part 120B may be smaller than a thickness, width, arc length or outer diameter of the pin portion 120 in the distal part 120C. The thickness, width, arc length and/or outer diameter in the intermediate part may be the smallest of the beam and that of the distal part 120C may be the largest of the beam. In other words, the thickness, width, arc length and/or outer diameter of each beam 121 may vary along the longitudinal axis A-A’.

[0054] Each beam 121 may thus have a flexible part in the intermediate part 120B, the flexible part providing the flexibility of the beam, i.e. the smallest second moment of area also referred to as second area moment or quadratic moment of area, of the beam. For example, a ratio of a second moment of area measured at the distal part 120C (for example at the contact surface 128) with regard to a second moment of area measured at the intermediate part, for example at the smallest outer diameter or cross-section, is 5 to 15, preferably 8 to 12, at most preferably about 10.

[0055] Due to this, a spring effect of the pin portion 120 may be obtained, i.e. an elastic deformation of each beam 121 with regard to the base portion 110, for example in a direction transversal to the longitudinal axis A-A’. Consequently, the beam extremity 121 E of each beam 121 may move at least radially and preferably along an arc of a circle with regard to the corresponding beam base part 121 B, with regard to the other beam extremities 121 E and/or with regard to the base portion 110, by an elastic deformation of the beam.

[0056] For example, the intermediate part 120B has a concave external surface and the distal part 120C has a convex external surface. The proximal part 120A may have a cylinder shape, i.e. a segment along a plan parallel to the longitudinal axis A-A’. For example, the proximal part 120A may have a circular cross-section along a plane perpendicular to the longitudinal axis A-A’ and a linear longitudinal section or linear section along a plane parallel to the longitudinal axis A-A’.

[0057] The distal part 120C may include a contact surface 128 intended for an electrical contact with the hollow body 200. For example, the contact surface 128 may be located on a part of the distal part 120C having the largest diameter or width. Preferably, the contact surface 128 is defined on a portion of the distal part 120C in which the distal part 120C, including the beams 121 and the grooves 122, has a constant diameter in an assembled configuration. The contact surface 128 may thus have a constant arc length along the longitudinal axis A-A’, i.e. a surface with a single radius of curvature on each of the beams 121 and/or a longitudinal section along the longitudinal axis A-A defined by a segment.

[0058] With reference to Fig. 3, a full pin body 100 is shown including the base portion 110 and only two beams 121 separated by two grooves 122 or one single groove 122T crossing the pin portion 120. The pin body 100 may have the beams 121 shown in Fig. 2, the two beams visible in Fig. 3 or alternatively six or eight beams. The central lumen 125 may have circular walls as visible in Fig. 2 or flat walls as visible in Fig. 3. The other features of the pin portion 120 of Fig. 3 may be similar to that of Fig. 2.

[0059] The base portion 110 may define a base wall 111 from which the pin portion 120 extends, a circumferential wall 112, for example providing the larger diameter of the pin body 100 and an abutment wall 113 intended to contact a portion of the case 400 (see Fig. 4). Further from the abutment wall 113 is an external surface 114, for example under the form of a protrusion or a pin, extending from the abutment wall 113 and preferably having a smaller diameter with regard to the circumferential wall 112.

[0060] With reference to Fig. 4, the spring-loaded contact is visible in an assembled configuration, with a two-beam pin body 100 according to Fig. 3. The pin body 100, the coil spring 300 and the hollow body 200 are received in the case 400 and aligned on the longitudinal axis A-A’. The pin portion 120, in particular the distal part 120C and the beam extremities 121 E is in contact with the coil spring 300 and with the hollow body 200.

[0061 ] The case 400 may have a first case extremity 401 , for example having a constant or similar diameter with regard to a case body 403, and a second case extremity 402 defining a recess with regard to the case body 403, i.e. a smaller internal diameter. The second case extremity 402 is open to let the external surface 114 through and protruding from the case 400 and is further adapted to form an abutment for the pin body 100, by contacting the abutment wall 113 of the base portion 110 in the extended configuration shown in Fig. 4. The hollow body 200 may be fixed in the first case extremity 401 for example by interference with a circumferential bulge 201 provided on the hollow body 200.

[0062] The hollow body 200 may include a hollow body base wall 210 and a hollow body circumferential wall 220 extending from the hollow body base wall 210 and including the circumferential bulge 201. The hollow body circumferential wall 220 may define a cavity 221 with the hollow body base wall 210 with an open extremity opposite to the hollow body base wall 210 and defined by an edge 222. For example, the edge 222 has a transversal surface with regard to the longitudinal axis A-A’, for example intended to face a direction toward the pin body 100. The bottom of the cavity 221 is defined by a base inner wall 223 that is transversal to the longitudinal axis A-A’ of springloaded contact 1000, for example with a planar, U- or V-shaped longitudinal section, as visible in Fig. 4.

[0063] The hollow body 200 receives at least a part of the pin portion 120 in an assembled configuration, within the hollow body circumferential wall 220. More particularly, a part of the pin portion such as a part or all the distal part 120C and including at least the beam extremity 120E may be accommodated into the cavity 221 , so that the contact surface 128 may electrically and mechanically contact the internal surface of the hollow body circumferential wall 220. Due to the spring effect of the pin portion 120, each beam 121 may apply a force on the internal surface of the hollow body circumferential wall 220, such as 0.3 N to 3 N, preferably 0.5 N to 2 N, at most preferably around 1 N.

[0064] Further, the hollow body 200 receives at least part of the coil spring 300, between an abutment formed by the base inner wall 223 and at least one of the beam extremities 121 E of the beams 121. The coil spring 300 may thus oppose a force to a relative movement of the pin body 100 with regard to the hollow body 200, such as a translation.

[0065] In the extended position shown in Fig. 4, the coil spring 300 may have a maximum length. For example, 5 to 30% of the length of the pin portion 120 may be accommodated in the hollow body 200, preferably 8 to 25% and for example 10 to 20% or 10 to 15%.

[0066] In a contracted position (not shown), the coil spring 300 may have a minimal length and the movement of the pin body 100 toward the hollow body 200 may be limited by the force of the coil spring 300 or by the abutment of the coils of the coil spring 300. For example, 90 to 100% of the pin portion 120, or of the beams 121 may be accommodated in the hollow body 200.

[0067] In use, the external surface 114 of the base body 100 may be in contact and electrically connected to a first external part, i.e. a first printed circuit board or PCB (now shown) and the hollow body base wall 210 may be in contact with a second external part such as a second PCB (not shown). The first external part may move with regard to the second external part, for example due to vibration or shocks.

[0068] Consequently, the pin body 100 may move toward the hollow body 200 in the contracted position, for example through a translation. In doing so, the contact surface 128 of the pin portion 120 travels across the cavity 221 i.e. slides on the inner surface of the hollow body circumferential wall 220, and the beams 121 may flex to maintain an electrical contact despite any variation of the diameter of the cavity 221 and/or in the case the pin body 100 and the hollow body 200 may be slightly tilted one with regard to the other, i.e. not perfectly aligned on the longitudinal axis A-A’. A relative rotation of the pin body 100 with regard to the hollow body 200 may also be allowed. When the force causing the movement has stopped, the coil spring 300 may bring the piston body 100 back to the extended position.

[0069] Due to the pin portion120 sliding inside the hollow body 200 and preferably to the elastic deformation or spring effect of the beams 121 , a safe movement of the pin body 100 and a reliable electrical connection may be ensured despite the presence of shocks or vibrations. The transmission of an important current is also allowed by the spring-loaded contact, even in the case of a slight tilt of the hollow body 200 with regard to the pin body 100 and in the case of important variation of temperature. Further, the spring-loaded contact 1000 can be manufactured with a reduced diameter, so that several spring-loaded contacts can be assembled into one electrical or electronic system to transmit large currents or several signals. The specific arrangement of the coil spring 300 between the pin body 100 and the hollow body 200 further allows reducing the overall diameter of the spring-loaded contact 1000.

[0070] One or more spring-loaded contacts may then be integrated to an electronic or electrical system in order to transmit electrical power and/or electrical signals.

[0071 ] Without being bound by any theory, it is believed that the specific geometry of the pin body and of the hollow body and their specific arrangement limit an internal resistance of the spring-loaded contact and thus limits temperature when an important current is transmitted. In dynamic use of the spring-loaded contact i.e. submitted to shocks and vibrations, the continuous contact between the pin body and the hollow body further contributes to limiting an increase in temperature.

[0072] The pin body 100 and/or the hollow body 200 may be obtained from any electrical conducting material, such as any metal or alloy. Preferably, they are obtained from an allow, such as brass or an alloy of Cu, Zn and Pb. The pin body 100 and/or the hollow body 200 may be coated, at least on the inner surface of the cavity 221 and on the contact surface 128 or the outer surface of the distal part 120C of the pin portion 120. The coating may include a nickel coating and/or a gold coating. For example, no lubricant is provided in the spring-loaded contact 1000.

[0073] Figs. 5A-5B show a spring-loaded contact 1001 similar to that shown in Fig. 4 with an additional movable insert 500. The movable insert 500 is located between the coil spring 300 and the pin body 100, in contact with the beam extremities 121 E. All other features may be similar to that of Fig. 4. The movable insert 500 may be a ball as visible in Figs. 5A-5B, a cylinder (not shown) or alternatively a more complex shape provided with a groove to receive the extremity of the coil spring 300 and a hole, a groove or mating pits to receive the beam extremities 121 E (now shown). [0074] The movable insert 500 may allow increasing the reliability of the springloaded contact 1001 by stabilizing the interaction between the coil spring 300 and the pin body 100.

[0075] Figs. 6A-6B shows a spring-loaded contact 1002 provided with a case 400, a hollow body 200 fixed to the case 400 and provided with two open extremities defined by two edges 222. A pin body 100 is inserted in the hollow body 200 though one of the open extremities and another pin body 101 is inserted in the hollow body through the other of the open extremities. The case 400 may be formed from two half cases 400A, 400B, to be joined to form the case 400. The case 400 may be symmetrical or at least have two second case extremities 402.

[0076] The coil spring 300 is accommodated in the hollow body 200 and is in contact with both the pin body 100 and the another pin body 101 . Both the pin body 100 and the another pin body 101 may be movable with regard to the case 400, whereas the hollow body 200 may be fixed with regard to the case 400. The pin body 100 and the another pin body 101 may be identical, as shown in Fig. 6. Further, two movable inserts may be provided (not shown), similarly to what is shown in Figs. 5A-5B. The spring-loaded contact 1002 may be especially adapted for shock and vibration-intensive applications.

[0077] The spring-loaded contacts 1000, 1001 , 1002 are all shown with a pin body 100 according to Fig. 3 but they can also include a pin body having a pin portion 120 according to Fig. 2 or any other pin body adapted to contact an inner surface of a hollow body. Further, the spring-loaded contacts 1000 and 1001 may have a pin body fixed to the case and a movable hollow body or a movable pin body and a movable hollow body.

MANUFACTURING

[0078] An example of a manufacturing method for the pin body 100 and for the spring-loaded contact 1000 is described below. [0079] First, the pin body 100 may be obtained by the method of Fig. 7. In a first step, the base portion 110 and the pin portion 120 may be obtained by screw machining a piece of metal or alloy. Then, the beams 121 may be obtained, for example by screw machining the central lumen 125 and then cutting at least one grooves 122 along the longitudinal axis A-A’ of the pin portion 120 to obtain at least two beams 121. The distal part 120C may thus have a first outer diameter or width, for example including the beams and the groove. This first outer diameter or width may be smaller than the internal diameter or width of the cavity 221 of the hollow body 200.

[0080] The beams may then be spread away one from the other, for example by introducing a conical shape inside the central lumen 125, or by introducing an inflatable element into the central lumen 125 and inflating it. The distal part 120C may thus have a second outer diameter larger than the first outer diameter when measured at the same location and for example larger than the internal diameter or width of the cavity 221 of the hollow body 200.

[0081 ] In a last, optional step, the beams may be calibrated, i.e. be brought back toward the central lumen by an external conical shape, in order for the distal part 120C to reach a third diameter larger than the first diameter but smaller than the second diameter and for example slightly larger than the internal diameter or width of the cavity 221 of the hollow body 200, so as to apply an appropriate force inside the cavity 221 in an assembled configuration.

[0082] In this method, the deformations of the beams are plastic deformations. Such a method allows obtaining a very accurate pin body 100 with small manufacturing tolerances. Then, the hollow body 200 and the case 400 may be obtained by screw machining or moulding and the coil spring 300 may be obtained by any method known in the art.

[0083] The spring-loaded contact 1000 may be assembled as follows. In a first step, the pin body 100 is aligned with the case 400 on the longitudinal axis A- A’ and introduced in the case 400, so as to contact the second case extremity 402. In a second step, the coil spring 300 is introduced into the case 400 in order to contact at least one of the beam extremities 121 E. The hollow body 200 is then aligned on the longitudinal axis A-A’ and moved toward the pin body 100 in order for the coil spring 300 to be secured in the cavity 221 . Finally, the hollow body 200 may be fixed to the first case extremity 401 , for example force-fitted with the circumferential bulge 201 and/or by welding.

[0084] With regard to the spring-loaded contact 1001 of Figs. 5A-5B, an additional step of introducing the movable insert 500 may be performed before the second step of introducing the coil spring 300 into the case 400.

[0085] With regard to the spring-loaded contact 1002 of Figs. 6A-6B, each pin body 100, 101 may be assembled into one half case 400A, 400B and the hollow body 200 with the coil spring 300 may be provided to one of the halfcases 400A, 400B. Both half cases 400A, 400B may then be assembled into a single case 400 and joined one with the other, for example though welding, gluing and/or force fitting. Having one of the half-cases 400A, 400B with a longer length may facilitate assembly by providing a stable accommodation of the hollow body 200 and of the coil spring 300 before the step of joining the half-cases 400A, 400B.

[0086] Such assembling methods allow efficiently obtaining the spring-loaded contact 1000, 1001 , 1002 with a limited number of steps and a low rate of defects.

[0087] The present disclosure is not limited to the above-described embodiment, and the following variations may be brought. In particular, the hollow body may be movable within the case and the pin body may be fixed to the case or both the pin body and the hollow body may be movable in the case. The external surface 114 and the hollow body base wall 210 are not limited to the shape visible in the figures and can include any connecting element allowing an electrical connection with an external part. For example, a connecting element can include a shaft, one or more recess and/or one or more protrusions. [0088] While the pin portion, the case and the hollow body visible in the figures have a circular or cylindrical base or cross-section, they may adopt any base or cross-section such as oval or square. The case 400 may be manufactured either in metal or in an insulating material such as an insulating plastic. The shape of the beams may be changed as long as they are adapted to contact the hollow body. Preferably, the spring effect of the beams shall be maintained.

[0089] Reference Numerals pin body 100, 101 base portion 110 base wall 111 circumferential wall 112 abutment wall 113 external surface 114 pin portion 120 proximal part 120A intermediate part 120B distal part 120C beam 121 beam base part 121 B beam extremity 121 E groove 122 single groove 122T central lumen 125 contact surface 128 hollow body 200 circumferential bulge 201 hollow body base wall 210 hollow body circumferential wall 220 cavity 221 edge 222 base inner wall 223 coil spring 300 case 400 half-case 400A, 400B first case extremity 401 second case extremity 402 case body 403 movable insert 500 spring-loaded contact 1000, 1001 , 1002

Claims

1 . A spring-loaded contact including:

• A hollow body,

• A coil spring received at least partially in the hollow body,

• A pin body comprising:

- A base portion adapted to be electrically connected with an external part,

- A pin portion comprising at least two beams extending from the base portion and contacting the hollow body, each beam including a distal part of the pin portion, distal from the base portion, wherein the distal part of at least one beam applies a force on the coil spring.

2. The spring-loaded contact according to claim 1 , wherein the distal part of the at least one beam is in contact with the coil spring.

3. The spring-loaded according to claim 1 , comprising a movable insert in contact with the distal part of the at least one beam and with the coil spring, wherein the distal part of the at least one beam applies a force on the coil spring through the movable insert.

4. The spring-loaded contact according to any of claims 1 to 3, wherein the pin body is made in one piece.

5. The spring-loaded contact according to any of claims 1 to 4, wherein the beams of the pin portion define a spring effect in a radial direction of the pin portion.

6. The spring-loaded contact according to any of claims 1 to 5, wherein the distal part of each beam comprises a contact surface contacting an inner wall of the hollow body.

7. The spring-loaded contact according to any of claims 1 to 6, wherein the distal part has a convex external surface.

8. The spring-loaded contact according to any of claims 1 to 7, wherein the pin portion comprises a central lumen between the beams, preferably defining an increasing diameter or width from a closed end inside the pin portion to an open end at the distal part of the beams.

9. The spring-loaded contact according to claims 1 to 8, wherein each beam includes an intermediate part of the pin portion, located between the distal part and the base portion, wherein the intermediate part has an intermediate cross-section and the distal part has a distal crosssection, and a perimeter enclosing the distal cross-section is larger than a perimeter enclosing the intermediate cross-section.

10. The spring-loaded contact according to claim 9, wherein an area of the distal cross-section is larger than an area of the intermediate crosssection.

11 . The spring-loaded contact according to claim 9 or 10, wherein the beams are separated by at least two grooves, the grooves having a width in the distal part larger than that in the intermediate part.

12. The spring-loaded contact according to claim 10 or 11 , wherein the intermediate part has a concave external surface.

13. The spring-loaded contact according to any one of claims 1 to 12, wherein the hollow body has an open extremity through which the pin body is at least partially received in the hollow body and a transversal wall opposite to the open extremity, wherein the coil spring is in contact with the transversal wall.

14. The spring-loaded contact according to any one of claims 1 to 12, wherein the spring-loaded contact comprises another pin body, the hollow body having an open extremity through which the pin body is at least partially received in the hollow body, and another open extremity through which the another pin body is at least partially received in the hollow body.

15. The spring-loaded contact according to any of claims 1 to 14, comprising a case accommodating at least part of the pin body and of the hollow body.