Threads for touchproof plug connectors

Abstract

To provide a screw for a touch-proof plug connector that can be flexibly used and is robust, safety and easy to handle.SOLUTION: A screw (1) for a touch-proof plug connector is equipped with a screw body (11) and a touch protective element (22). The screw body (11) is equipped with a screw head part (12), and a shank (14) starting from the screw head part (12) and extending till a screw tip end portion (13) in a screwing direction. A connection element is formed at the screw tip end portion (13), and the touch protective element (22) is provided with at least one connection device configured as a connection counterpart component to the connection element for connecting the touch protective element (22) to the screw body (11), on a coupling side. The touch protective element (22) has, at least on the front side, an electrical insulation surface turning in the screwing direction while the screw body (11) and the touch protective element (22) have been connected.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a screw for a touchproof plug connection, in particular for an electrical connector, comprising a screw body and a touch protection element, the screw body comprising a screw shank running along a screwing direction starting from the screw head to the screw tip.

[0002] The invention further relates to an electrical connector comprising an electrically insulating connector housing, a contact element and a tightening screw.The invention additionally relates to an electrical plug connection comprising an electrical connector and a mating electrical connector. [Background technology]

[0003] Electrical plug connections having threads for a screw connection of a connector and a counter connector are known in the prior art. The screw connection ensures a robust and stable contact. Such plug connections are used, for example, in the automotive field, where the plug connection must be resistant to vibrations and high temperatures. There is a particularly high demand for electrical plug connections used in the high voltage range, which are exposed to high currents and high voltages. Such high voltage connectors are used in the automotive field, especially in electric and / or hybrid vehicles, for example to ensure contact with battery modules of traction batteries and other high voltage connection points outside the battery. To ensure that the plug connection is handled safely during assembly or during inspection or during use, such plug connections are configured to be touchproof. Touchproofness ensures that there is no risk of unintentional contact of a person's fingers with the current-carrying elements, so that this type of plug connection can be handled easily and safely.

[0004] For example, screwed high voltage plug connections are known which are configured to be touchproof with respect to IPxxB according to ISO 20653, forming very robust contacts which are easy to handle in a typical production environment.

[0005] The threads of such plug connections are typically protected against accidental contact at both the screw head and screw tip.

[0006] However, due to different geometrical requirements depending on the vehicle type and battery configuration, threads with specifically adapted geometries must be manufactured for each application, different thread lengths require different tools, and prior art touchproof threads are designed only for certain plug connections and cannot be used in other cases. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE PRESENT EMBODIMENT The present invention therefore aims to provide a screw for a touchproof plug connection which can be flexibly used and at the same time is robust, safe and easy to handle. [Means for solving the problem]

[0008] This object is achieved by a screw according to the invention for a touch-proof plug connection comprising a screw body and a touch-protection element. The screw body comprises a screw head and a screw shank which runs along the screwing direction starting from the screw head to the screw tip. A connection element is formed at the screw tip, the touch-protection element being provided on the coupling side with at least one connection device which is configured as a connection counter part for the connection element. The connection device is configured to connect the touch-protection element to the screw body, the touch-protection element having an electrically insulating surface at least on the front side. In the connected state, i.e. when the screw body and the touch-protection element are assembled, the front side faces in the screwing direction.

[0009] Furthermore, this object is achieved by an electrical connector according to the invention for an electrical plug connection, in particular for a high current and / or high voltage plug connection of the type mentioned at the beginning, with a touch-protective screw according to the invention. An electrical plug connection for high current and / or high voltage contacts, in particular in the vehicle sector, achieves this object in that it comprises at least one connector according to the invention and a counter connector.

[0010] The touchproof screw according to the invention has the advantage that the two-part structure consisting of a screw body and a touch protection element connectable to the screw body provides a flexible system with which a substantially standardized screw can be used, which only needs to be provided with a connection element at the screw tip. The adaptation to the different geometries of connectors or plug connections used in different vehicles can be implemented in the touch protection element independently of the screw. In addition, the screw body can also be used as a screw without the touch protection element. The screw is robust and easy to manufacture due to the mating part that allows the touch protection element to be connected to the screw body. The screw offers a wide variety of variation possibilities and a high degree of flexibility at the same time due to the two-part design.

[0011] The invention can be further improved by the following embodiments, which are advantageous alone and can be combined in any combination with one another.

[0012] According to one possible embodiment, the touch protection element may be connected to the screw body by a form-fit, frictional engagement and / or adhesive bond / positive substance-fit connection between the connection device and the connection element. The connection device of the touch protection element and the connection element of the screw body may represent complementary connection counterparts that can be joined using common production techniques, i.e. connected to each other at the joint. This connection allows the touch protection element to be fixed axially to the screw body in the screw-in direction. This connection may be a static connection that prevents both a displacement of the touch protection element in the axial direction along the screw-in direction relative to the screw body and a radial movement perpendicular to the screw-in direction. A complete fixation that does not allow any relative movement of the touch protection element connected to the screw body is also possible.

[0013] If the coupling side of the touch protection element faces in the opposite direction to the front side, the connection between the connecting element of the screw body and the connecting device of the touch protection element is very simple. Due to the spatial distance between the electrically insulating front side of the touch protection element on the one hand and the coupling side provided for connection to the connecting element on the other hand, there is a high degree of configuration freedom both with regard to the shape and size of the insulating front side and the configuration of the at least one connecting device.

[0014] The connection counter part, i.e. the connection device and the connection element, may be configured such that when joined, i.e. in the connected state, the touch protection element is aligned along the screwing direction. The touch protection element may be aligned in line with the screw shank in the screwing direction. The touch protection element may have a size such that, when viewed in the screwing direction, it does not protrude laterally beyond the screw shank in the connected state to the screw body. This ensures that the screw according to the invention, with the touch protection element connected to the screw body, can be screwed in and the touch protection element does not impair the screw connection between the screw and its counter thread.

[0015] The connection element and the connection device may be complementary mating parts of a pressure-fit connection, for example a press-fit or trilobular-fit press connection in which one of the mating parts has a trilobular cross-section that can be pressed into a corresponding opening of the mating part by frictional engagement. In another embodiment, one of the mating parts may be configured as a Morse taper allowing a positive surface pressure.

[0016] According to a further embodiment, the connection element and the connection device may be part of a releasable connection. The touch protection element may then be releasably connected to the screw body. This is advantageous for maintenance purposes and allows the element of the screw according to the invention, e.g. the screw body, to be reused in different application environments. Counterparts of form-fit and / or force-fit connections, e.g. screw connections or latches, are suitable as counterparts of a releasable connection.

[0017] In one embodiment, the screw tip may comprise a cavity for receiving the coupling side of the touch protection element, so that a particularly compact screw is obtained. The connecting element may be arranged in the cavity. This is advantageous in that the joint of the two connected counter parts is not accessible from the outside and is therefore protected. Configurations are also conceivable in which the connecting element is formed in the screw tip, for example a protrusion with the connecting element is present in the screw tip. This protrusion may protrude from the screw tip in the screw-in direction.

[0018] The connecting elements may be provided with threads or latching devices for a form-fit connection. A snap connection / latch may be realised by the latching device, whereby the touch protection element can be connected to the screw body removably or non-removably by a simple form-fit. For example, the screw tip may be provided with an axial stop, into which a complementary latch hook may engage behind in the opposite direction to the screwing direction to realise a form-fit snap or latch connection. Of course, the complementary connecting counterparts, i.e. the connecting elements of the screw body and the connecting devices of the touch protection element, may always be configured in an inverse relationship, even if this is not explicitly stated in the present description. For example, the touch protection element may also have a latch stop, e.g. a back taper, whereby a connecting element of the screw body configured as a latch hook may engage to form a snap connection.

[0019] According to a further embodiment, the screw tip may have a cavity with an internal thread. This cavity may for example be configured as a blind drilled hole thread which is formed in the screw body starting from the screw tip in the opposite direction to the screwing direction. Such a cavity with an internal thread is easy to manufacture, even with standardized screw bodies. The touch protection element may comprise a complementary connection element in the form of a mating side with an external thread which can be connected to such a connection element by form-fit and force-fit. Such a screw connection offers the option of a robust and reliable, yet repeatedly removable connection between the contact element and the screw body.

[0020] In a further embodiment, the touch protection element may comprise a touch protection body which is coated at least on the front side with an electrically insulating material. This configuration increases the flexibility of the screw according to the invention. The touch protection body may be optimized with respect to its material properties, for example with respect to possible impedance. The front side covered with an electrically insulating material ensures the main function, namely touch protection. In this embodiment, the touch protection body may be configured independently of the electrically insulating material, provided that the front side is coated with the electrically insulating material. To cover the front side with the electrically insulating material, this front side may be coated with the electrically insulating material or the electrically insulating material may be cast, for example in an injection molding process. The front side may be covered by a separate insulating element, which shall be discussed in more detail below.

[0021] If the touch protection body is made of metal, a particularly stable connection and good heat dissipation and impedance effect can be obtained.

[0022] In one embodiment, the touch protection body can be a threaded rod whose mating side threads correspond to the connecting device. This is a cost-effective solution, especially when a threaded rod of standard industry dimensions and materials is used as the touch protection body.

[0023] In a further embodiment, the touch protection body may be covered on all sides by an electrically insulating material, which ensures a particularly effective touch protection in the screw tips, since the touch protection is electrically insulated not only on the front side but also on the flanks of the touch protection body up to the joining area. The touch protection body may be made of an electrically insulating material, for example may be integrally formed from an electrically insulating material. This also allows a particularly effective touch protection in the region of the screw tips.

[0024] In a further embodiment, the touch protection element may comprise an insulating element that can be attached to the front side of the touch protection body. The insulating element may be connected to the touch protection body by form-fitting and / or force-fitting. The insulating element may be removably connected to the touch protection body, for example by screw connection or latch connection. The options explained above regarding the connection between the connection element of the screw body and the connection device of the touch protection element may be regarded as inter alia joining elements for forming a connection between the insulating element and the touch protection element. Here, the insulating element may be provided with a mounting device that is configured to connect the insulating element to the touch protection body. The mounting device may be, for example, a latch hook, a screw thread or a press-fit element.

[0025] According to one embodiment, the insulating element may be an insulating cap. Such an insulating cap may be configured to cover at least the front side of the touch protection body. The insulator may in particular be configured to cover in an electrically insulating manner the front side of the touch protection body as well as the flank adjacent to the front side. The insulating cap may be provided with an internal thread that corresponds to a complementary connection device to the touch protection body in the form of a threaded rod.

[0026] The invention will now be described, by way of example only, with the aid of embodiments and with reference to the accompanying drawings, in which elements in the drawings that correspond to one another in terms of structure and / or function are provided with the same reference signs, in which:

[0027] The combination of features shown and described in the individual embodiments is for illustrative purposes only. With regard to the above description, a feature of an embodiment may be omitted if its associated technical effect is not important in a particular application. Conversely, with regard to the above description, an additional feature may be added to an embodiment if the technical effect of the feature is advantageous in a particular application. [Brief description of the drawings]

[0028] [Figure 1]1 is a schematic cross-sectional view of an electrical plug connection according to the present invention in a connected state, the electrical plug connection having a connector according to the present invention, the connector comprising a screw according to a first embodiment of the present invention; [Diagram 2] 11 is a schematic cross-sectional view of a connector according to the present invention having a screw according to a further embodiment of the present invention; FIG. [Figure 3A] 3A shows the elements of the clamping screw of FIG. 1 with the screw body shown in a schematic perspective view and a cross-sectional view of parts of the touch protection element in the pre-assembled state (FIG. 3A). [Figure 3B] 3B shows the tightening screw of FIG. 1 with the screw body shown in a schematic perspective view and a detailed view of said screw in the assembled state of the touch protection element; FIG. [Figure 4] FIG. 4 is a detailed view of a clamping screw according to the present invention, according to a further embodiment. [Diagram 5] FIG. 2 is a schematic diagram of a touch protection element according to a further embodiment. [Figure 6] FIG. 2 shows a detailed view of a further embodiment of a fastening screw according to the invention in a schematic cross-sectional view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Before presenting specific embodiments of the screw 1 according to the present invention with reference to Figures 3 to 6, the basic background of the screw 1 according to the present invention in a connector 2 which may be part of a non-contact plug connection 3 will first be explained with reference to Figures 1 and 2.

[0030] 1 shows an embodiment of a touchproof plug connection 3 in a connected or closed state. The electrical plug connection 3 comprises an electrical connector 2 and a mating electrical connector 4. The electrical connector 2 comprises an electrically insulating connector housing 5, contact elements 6 and a screw 1, which may also be referred to as a clamping screw. The specific design of the clamping screw 1 will be discussed in detail later.

[0031] The contact elements 6 are accommodated in the connector housing 5 and are accessible along a connection direction V along which the connector 3 is mechanically and electrically connected to its mating connector 4 .

[0032] The mating connector 4 comprises a mating connector housing 7 in which mating contact elements 8 are accommodated. In the connected state of the plug connection body 3 shown in FIG. 1, the contact elements 6 of the connector 3 are conductively connected to the mating contact elements 8 of the mating connector 4.

[0033] The contact elements 6 may be connected to electrical conductors 9, for example ribbon cables.

[0034] The contact element 6 has a through hole 10 through which a thread body 11 of the screw 1 passes. The screw body 11 comprises a screw head 12 and a screw shank 14 which runs in a screwing direction E starting from the screw head 12 to a screw tip 13. The screw shank is provided with a thread 15, in particular in the region of the screw tip 13. The screw tip 13 and the part of the screw shank 14 which is provided with the thread 15 are arranged on a contact side 16 of the connector housing 5 in the region of the contact element 6. The connector 2 can be mechanically connected via the thread 15 to an internal thread 17 of the counter connector 4 and can be held in the connected state.

[0035] The screw head 12 is accessible from a mounting side 18 of the connector 3 and is provided with an interface 19 for engagement of an instrument allowing for applying torque to the clamping screw 1. The interface 19 may be, for example, a hex socket, a hexalobe socket, a slot, a Phillips recess or a hex head, or a hexalobe head as in the illustrated embodiment, or any other standard.

[0036] The thread 15 may be any thread, such as a metric ISO thread (DIN 13-1), for example a regular thread having standard sizes, such as M3, M4, M5, M6 or M8.

[0037] In the case of the screw body 12, a bearing surface 20 is provided at the transition between the screw head 12 and the screw shank 14, facing in the screw-in direction E, by means of which a force is transmitted to the contact element 6. The bearing surface 20 is formed by a so-called seat surface of the screw head 12.

[0038] To configure the connector 2 to be touchproof even at the mounting side 18, the screw head 12 is covered by an electrically insulating protective cap 21 so that when the screw 1 is tightened to mechanically and conductively connect the connector 2 to the mating connector 4, there is no risk of an instrument or a user's finger coming into contact with the conductive area of ​​the screw 1 at the mounting side 18.

[0039] As can be seen in particular in Figure 2, not only the mounting side 18 of the connector 2 but also the contact side 16 arranged opposite it is configured to be touch-proof by means of the screw 1 according to the invention with the touch protection element 22, which is now arranged and aligned in the connector 1 so as to exclude access to the contact elements 6 in the contact side 16 together with the connector housing 5, since it blocks the access opening 23, in particular for a human finger.

[0040] Figures 3A and 3B show a first embodiment of a screw 1 according to the invention, for example for a touch-proof plug connection 3 included in the connector 2 or plug connection 3 of Figure 1. Figure 3A shows the screw body 11 in a schematic perspective view. The elements of a touch protection element 22 of this embodiment are shown diagrammatically in a longitudinal section. Figure 3B shows the area of ​​the screw shank 14 and the screw tip 13 with the thread 15 in the assembled state, i.e. in the state in which the touch protection element 22 is connected.

[0041] The connecting element 24 is formed in the screw tip 13. The connecting element 24 may have a cavity 57 for receiving the mating side 26 of the touch protection element 22. In the exemplary embodiment of Fig. 3, the connecting element 24 is configured as a blind drilled hole 25 starting from the screw tip 13 and extending in the opposite direction to the threading direction E into the interior of the screw shank 14. The blind drilled hole 25 has a predetermined blind drilled hole diameter D25.

[0042] The touch protection element 22 is provided with a connection device 27 at the connection side 26. The connection device 27 is configured as a complementary connection partner to the connection element 24 of the screw body 11 for connecting the touch protection element 22 to the screw body 11. In the illustrated embodiment, the connection is realized as a press connection. The touch protection element 22 has a press cone 28 as the connection device 27. The press cone tip 29 has a diameter D29 at the connection side 26 that is smaller than the diameter D25 of the blind drilled hole 25. Starting from the press cone tip 29, the press cone 28 widens up to a transition region 30. In this transition region 30, the diameter D30 of the press cone 28 is larger than the diameter D25 of the blind drilled hole. The press cone 28 of the touch protection element 22 can then be pressed into the blind drilled hole 25, and by means of this press connection the touch protection element 22 can be connected to the screw body with a press fit.

[0043] The touch protection element 22 in the embodiment of Figure 3 is formed not only by a touch protection body 31 having a press cone 28, but also by an insulating element 33 which can be attached to the front side 32 of the touch protection body 31 and which is shown separately in Figure 3A and in the assembled state, i.e. attached to the touch protection body 31, in Figure 3B.

[0044] The front side 32 of the touch protection body 31 is opposite to the coupling side 26. In the assembled state, the touch protection element 22 of Fig. 3 is connected to the screw shank 14 in a line-up manner in the screw-in direction E at the screw tip 13. The outer diameter D33 of the insulating element 33 is smaller than the diameter D15 of the screw thread 14 so that the connected touch protection element 22 does not damage the screw 1 when screwed in.

[0045] In the embodiment shown, the insulating element 33 is configured as an insulating cap 34 which, in the assembled state, covers the front side 32 and the part of the touch protection body 31 which protrudes from the screw tip 13 in the connected state, in particular the transition area 30.

[0046] In the embodiment shown, the insulating cap 34 is connected to the touch protection body 31 in a form-fitting manner, by means of a latching or snap connection. The touch protection body 31 is provided at its front side with a latch stop 35. For this purpose, the front side 32 of the touch protection body 31 is configured in the shape of a mushroom head and forms a collar 36 with a collar diameter D36 which is larger than the diameter D30 in the transition region and smaller than the outer diameter D33 of the insulating cap 34. The latch stop 35 formed by the collar 36 points substantially in the direction of the press cone tip 29.

[0047] The insulating cap 34 comprises a latch arm 37 which is elastically bendable and forms a snap connection together with the latch stop 35. The latch arm 37 comprises a latch hook 38 at its distal end which can engage with the latch stop 35 formed by the flange 36 in order to fix the insulating cap 34 axially in the screwing direction E to the touch protection body 31, as shown in Fig. 3B. The connected touch protection element 22 then presents an electrically insulating surface at the front side 32 which faces the screwing direction E in the connected state of the screw body 11 and the touch protection element 22 and ensures protection against contacts. The latch hook 38 forms a mounting device 39 which is configured to connect the insulating element 33 to the touch protection body 31 by a latch or snap connection in the embodiment of Figs. 3A and 3B.

[0048] A further embodiment of the screw 1 according to the invention is shown below with reference to figure 4. Figure 4 shows, in a schematic view in longitudinal section, only the front part of the screw shank 14 together with the screw tip 13 and the connecting element 24. The touch protection body 31 of the touch protection element 22 is shown as a schematic side view, and the insulating element 33 is shown in figure 4 in schematic side view and partially in section.

[0049] Only the differences of this embodiment of the screw according to the invention compared to the previous embodiment of FIG. 3 will be discussed in more detail below.

[0050] In the embodiment of Fig. 4, the screw shank 14 is also configured with a cavity 57 at its screw tip 13. The connecting element 24 is likewise of the type of blind drilled hole 25. In contrast to the previous embodiment, the blind drilled hole 25 of the connecting element 24 in Fig. 4 is provided with an internal thread 40 as the connecting element 24. In particular, the connecting element 24 in Fig. 4 is configured as a blind drilled hole thread 41, which allows a threaded connection between the touch protection element 22 and the screw body 11 and thereby a form-fit and force-fit connection.

[0051] In the embodiment of Fig. 4, the touch protection body 31 is configured as a threaded rod 42. The diameter D43 of the rod thread 43 corresponds to the internal thread 40 of the blind drilled hole thread 41, so that the threaded rod 42 can be screwed into the blind drilled hole thread 41. Via the rod thread 43 as connecting device 27, the touch protection element 22 can be connected in a simple and structurally stable manner to the connecting element 42 of the threaded body 11, i.e. to the internal thread 40 of the blind drilled hole thread 41.

[0052] For electrical insulation of the front side 32 of the threaded rod 42, an insulating element 33 is provided which is configured as an insulating cap 34. In contrast to the embodiment in FIG. 3, the insulating cap 34 in this embodiment comprises a cap thread 44 which allows the insulating cap 34 to be screwed onto the front side 32 of the threaded rod 42.

[0053] The embodiment of FIG. 4 can be used in a modular and flexible way and is inexpensive to produce, especially if standard threaded rods are used. The overall length of the screw 11, especially in the region of the touch protection element 22, can be precisely adjusted in a structurally simple manner by the length L42. The insulating cap 34 is pot-shaped, with a cap base 45 which in the assembled state abuts against the front side 32 of the threaded rod 42 and electrically insulates it. The lateral cap walls 46 cover the lateral flanks 47 of the threaded rod 42 at the front side 32 of the threaded rod 42 and insulate these areas. By selecting the cap length L46, it can be determined in a simple manner over which length of the threaded rod 42 the flanks 47 of the threaded rod 42 are insulated.

[0054] The modular construction of the screw 1 according to the embodiment of Fig. 4 allows for a large number of different possible applications and makes it possible to reuse the screw 1 also in other environments. For this purpose, for example, only the threaded rod 42 or the insulating cap 34 has to be exchanged to accommodate the changed geometry of the new plug connection 3. This embodiment is also advantageous with regard to maintenance and repairs.

[0055] A further embodiment of the touch protection element 22 is shown in Fig. 5. This embodiment comprises a touch protection element 22 with a rod-shaped touch protection body 31. The touch protection body 31 may be made, for example, from metal, which provides good strength. The touch protection body 31 is surrounded on all sides by a coating 48. The coating 48 is made from an electrically insulating material and ensures that the touch protection element 22 of this embodiment guarantees the required touch-proofness.

[0056] In the embodiment shown, the coating is formed with a rod thread 43, so that the touch protection element 22 in the embodiment of Fig. 5 takes the form of an electrically insulating threaded rod 42 towards the outside. In this embodiment, the insulating cap 34 may be omitted. The insulating element 33 of Fig. 5 is therefore an electrically insulating coating 48. The coating 48 may be formed as a rod thread 43 directly around the touch protection body 31, for example by an injection molding process. It is also possible to first coat the touch protection body 31 with the coating 48 and then form the rod thread 43 in the coating.

[0057] Finally, a further embodiment of the screw 1 according to the invention shall also be discussed with reference to figure 6, in which the front region 32 of the screw body 11 with the touch protection element 22 attached is shown diagrammatically in longitudinal section.

[0058] Here too, the screw tip 13 is provided with a blind drilled hole 25 which is formed in the screw shank 14 starting from the screw tip 13 in the opposite direction to the screwing direction E.

[0059] In this embodiment, a form-fit connecting element 24 in the form of a latching device 58 is configured as the connecting element 24. For this purpose, the blind hole 49 is provided with an undercut in the form of a protrusion 50, which widens the diameter of the blind drilled hole 25 to a protrusion diameter D50, i.e. the part of the blind drilled hole 25 which is arranged opposite the opening of the screw tip 13. By means of the protrusion 50, a circumferential groove 51 is generated in the blind hole 49, forming a connecting shoulder 52 which faces away from the screwing direction E.

[0060] To attach the touch protection element 22 to the connection element 24, the connection surface 53 of the touch protection element 22 can engage with this connection shoulder 52 by form-fitting.

[0061] The touch protection body 31 of the touch protection element 22 has dimensions complementary to the diameter D25 of the blind drilling hole 25 and is substantially cylindrical. An elastically configurable connection arm 54 as the connection device 27 is arranged on the mating side 26 of the touch protection body 31. The connection arm 54 extends away from the touch protection body 31 substantially parallel to the longitudinal axis of the touch protection body 31, which in the assembled state coincides with the screwing direction E. A latch hook 38 is arranged on the distal end 55 of the connection arm 54.

[0062] The touch protection element 22 of Fig. 4 can be easily connected to the screw body 11 by first inserting the latch hook 38 into the blind drilling hole 25. By doing so, the connection arms 54 bend inwards towards each other until they enter the projections 50 shaped as grooves 51. The connection arms 54 then spring back to their rest state. The connection faces 53 of the latch hooks 38 engage with the connection shoulders 52 of the grooves 51 and the touch protection element 22 is fixed to the screw body 11 by a form fit.

[0063] The touch protection body 51 in Fig. 6 has a touch protection head 56 at its front side 32. In order to achieve a better touch protection effect, the diameter D56 is enlarged in this area, but the diameter D56 of the touch protection head is smaller than the diameter D15 of the screw thread.

[0064] The touch protection element 22 in the exemplary embodiment shown in Fig. 6 is of one-piece construction, i.e. manufactured in one piece from a plastic material and can be produced, for example, by an injection molding process, which allows cost-effective mass production and provides both electrical insulation properties and the formation of elastically deformable connecting arms 54 with connecting hooks. [Explanation of symbols]

[0065] 1 Screw 2 Connector 3 Plug connector 4 Mating Connector 5 Connector housing 6 Contact Elements 7 Mating connector housing 8 Counterpart Contact Elements 9 Conductors 10 Passing hole 11 Screw body 12 Screw head 13 Screw tip 14 Screw shank 15 threads 16 Contact side 17 Female thread 18 Mounting side 19 Interface 20 Pressing surface 21 Protective Cap 22 Touch Protection Elements 23 Access opening 24 Connection elements 25 Blind Drilling Hole 26 Joint side 27 Connected Devices 28 Press Cone 29 Press cone tip 30 Transition Zone 31 Touch Protection Body 32 Front 33 Insulating Elements 34 Insulating cap 35 Latch stopper 36 Flange 37 Latch Arm 38 Latch hook 39 Mounting Devices 40 Female thread 41 Blind Drilling Hole Thread 42 Threaded Rod 43 Rod Thread 44 Cap Thread 45 Cap base 46 Cap wall 47 Lateral Flank 48 Insulating Coating 49 Blind Hole 50 Protrusion 51 Groove 52 Connection step 53 Connection Surface 54 Connecting arm 55 Distal end 56 Touch Protection Head 57 Cavity 58 Latch Device D15 diameter thread D25 diameter blind drilling hole D29 Press cone tip diameter D30 Diameter transition area D33 diameter insulating element D36 diameter flange D43 diameter rod thread D50 diameter protrusion D56 diameter touch protection head E Screw-in direction L42 Threaded rod length L46 Cap wall length V Connection direction

Claims

1. A screw (1) for a touch-proof plug connection (3) comprising a screw body (11) and a touch protection element (22), The screw body (11) includes a screw head (12) and a screw shank (14) extending from the screw head (12) to a screw tip (13) along a screw-in direction (E), A connecting element (24) is formed on the screw tip (13), the touch protection element (22) is provided with at least one connection device (27) on a coupling side (26) configured as a connection counterpart to the connection element (24) for connecting the touch protection element (22) to the screw body (11); The touch protection element (22) has, at least at its front side (32), an electrically insulating surface facing the screw-in direction (E) in the connected state of the screw body (11) and the touch protection element (22); The touch protection element (22) comprises a touch protection body (31) which is coated with an electrically insulating material at least on the front side (32). Screw (1).

2. The screw (1) according to claim 1, wherein the touch protection element (22) is connected to the screw body (11) by a form fit, a frictional engagement and / or an adhesive bond between the connecting device (27) and the connecting element (24).

3. The screw (1) according to claim 1 or 2, wherein the touch protection element (22) is removably connected to the screw body (11).

4. The screw (1) according to claim 1 or 2, wherein the touch protection element (22) has a size such that, when viewed in the screwing direction (E), it does not protrude beyond the screw shank (14) when connected to the screw body (11).

5. The screw (1) according to claim 1 or 2, wherein the screw tip (13) has a cavity (57) for receiving the coupling side (26) of the touch protection element (22).

6. The screw (1) according to claim 1 or 2, wherein the connecting element (24) comprises a screw thread (40) or a latching device (58).

7. The screw (1) according to claim 5, wherein said cavity (57) has an internal thread (40).

8. The screw (1) according to claim 1 or 2, wherein the touch protection element (22) is made from an electrically insulating material.

9. The screw (1) according to claim 1, wherein the touch-protective body (31) is covered on all sides by the electrically insulating material.

10. The screw (1) of claim 1, wherein the touch protection body (31) is made from metal.

11. A screw (1) for a touch-proof plug connector (3) comprising a screw body (11) and a touch protection element (22), The screw body (11) includes a screw head (12) and a screw shank (14) extending from the screw head (12) to a screw tip (13) along a screw-in direction (E), A connecting element (24) is formed on the screw tip (13), the touch protection element (22) is provided with at least one connection device (27) on a coupling side (26) configured as a connection counterpart to the connection element (24) for connecting the touch protection element (22) to the screw body (11); The touch protection element (22) has, at least at its front side (32), an electrically insulating surface facing the screw-in direction (E) in the connected state of the screw body (11) and the touch protection element (22); The touch protection element (22) comprises a touch protection body (31) and an insulating element (33) attachable to the front side (32) of the touch protection body (31); Screw (1).

12. The screw (1) according to claim 11, wherein the insulating element (33) is provided with a mounting device (39) configured to connect the insulating element (33) to the touch protection body (31).

13. The screw (1) according to claim 12, wherein the insulating element (33) is connected to the touch-protection body (31) by form-fitting and / or force-fitting.

14. The screw (1) according to claim 11, wherein said insulating element (33) is an insulating cap (34).

15. The screw (1) according to claim 11, wherein the touch-protective body (31) is made of metal.

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