Connection device for fastening an electrical contact element to an electrical conductor

Abstract

The invention relates to a connection device (1) for fastening an electrical contact element (9) having a central opening (67) to an electrical conductor (11). In order to facilitate compensation of position tolerances between the electrical contact element (9) and the electrical conductor (11), a connection device (1) is provided which comprises an expansion collar (3) and an expansion element (5) which can be inserted into the expansion collar (3), wherein the expansion collar (3) is designed to be able to be inserted in a slidable manner into the central opening (67) of the electrical contact element (9), and wherein the expansion collar (3) expands to clamp the electrical contact element (9) when the expansion element (5) is fully inserted into the expansion collar (3).

Description

Technical Field

[0001] The present invention relates to a connection device for fastening an electrical contact element to, in particular, an electrical contact conductor, especially a conductor rail. Background Technology

[0002] In some cases, securing and making electrical contacts on conductors, particularly on conductor rails, can be technically complex. For example, due to limited available installation space or fixed specifications of the conductor's position relative to the electrical contact element, it may be difficult to secure the electrical contact element to the conductor.

[0003] Fastening can be more complex because the position of the electrical conductor relative to the electrical contact element may deviate from the intended position during assembly. Therefore, it is necessary to compensate for positional tolerances. This problem is typically solved using connection devices that at least partially utilize flexible electrical conductors or contact elements. However, this solution involves technical work and is therefore expensive. Summary of the Invention

[0004] Therefore, the object of the present invention is to provide a connection device of the above type, which provides both a simple structure and the possibility of compensating for positional tolerances between electrical contact elements and electrical conductors.

[0005] According to the invention, this object is achieved by a connecting device designed for securing an electrical contact element having a central opening to an electrical conductor. The connecting device includes an expansion collar connectable to the electrical conductor and an expansion element insertable into the expansion collar. The expansion collar is designed to be slidably inserted into the central opening of the electrical contact element, particularly in an axially slidable manner, and the expansion collar expands to clamp the electrical contact element when the expansion element is fully inserted into the expansion collar.

[0006] The above-mentioned objectives are achieved in a simple manner by providing a connecting device according to the invention. The expansion collar can be connected to an electrical conductor, particularly to a conductor rail. It can be conductive and / or mechanically connected to the electrical conductor. An electrical contact element can be arranged relative to the expansion collar such that the expansion collar is slidably inserted into the contact element, particularly axially.

[0007] The sliding arrangement allows for compensation of positional tolerances between the electrical conductor and the electrical contact element. Once the electrical contact element and the expansion ring are positioned relative to each other in the desired manner, the expansion element can be inserted into the expansion ring. The expansion ring then expands and applies pressure to the electrical contact element. This allows the electrical contact element to be mechanically secured to the expansion ring. Simultaneously, a conductive connection is established between the two parts through the contact between the expansion ring and the electrical contact element.

[0008] Furthermore, the present invention can be improved through the following embodiments, each of which is advantageous in itself and can be combined with each other in any desired manner. The above embodiments and their associated advantages will be described below.

[0009] Connection devices may include electrical contact elements. However, typically, connection devices and electrical contact elements are distributed as separate items. An electrical contact element may, for example, be part of a plug, which is separately assigned but configured for connection to the connection device.

[0010] To facilitate the expansion of the expansion ring, the expansion ring is preferably provided with at least one longitudinal slot. The longitudinal slot extends along the longitudinal direction of the expansion ring and opens toward the axial end of the expansion ring.

[0011] Preferably, the connecting device includes a clamping contact ring configured to receive an extension ring and an electrical contact element, wherein the extension ring extends toward the inner wall of the clamping contact ring when the extension element is fully inserted into the extension ring. The clamping contact ring is preferably configured for attachment to an electrical conductor, particularly to a conductor rail. When the extension element is fully inserted into the extension ring, the electrical contact element can be clamped between the extension ring and the clamping contact ring. In this case, the extension ring can press the contact element against the inner wall of the clamping contact ring.

[0012] An externally accessible contact socket may extend between the inner walls of an expansion sleeve and a clamping contact sleeve for slidably receiving at least a portion of an electrical contact element.

[0013] Viewed along the axial direction of the extending collar, the contact socket can have an annular cross-section. This allows the entire hollow cylindrical contact socket to extend from the outside into the clamping contact collar.

[0014] The extension ferrule may have an extension element socket configured to receive an extension element. Particularly preferred is that the extension element socket tapers gradually along the insertion direction of the extension element. This allows the extension ferrule to easily expand when the extension element is inserted.

[0015] Alternatively, or in addition to the tapered extension member socket, the extension element may be conical or wedge-shaped.

[0016] The extension ring can consist of two parts, including a clamping element and a receiving element disposed within the clamping element and having a socket for the extension element. While this increases the number of parts, it simplifies the manufacturing process.

[0017] In particular, the receiving element can be held in the clamping element in a rotation-resistant manner.

[0018] Particularly preferably, the expanding ring has an internal thread, and the expanding element has a complementary external thread. Particularly preferably, the inner diameter of the internal thread can gradually taper along the insertion direction of the expanding element. Alternatively, the outer diameter of the external thread on the expanding element can increase in the opposite direction to the insertion direction. The internal thread can also be tapered, and the external thread can be enlarged.

[0019] In the two-part design of the extended collar, it is preferable that the receiving element is provided with an internal thread.

[0020] As an alternative to the embodiment including threads, the extension element and the extension element socket may each have an elliptical or other cross-section, wherein rotation of the extension element within the extension element socket causes the extension ring to expand.

[0021] The connecting device may include an electrical contact element having a contact portion configured to connect to an extension ring, the contact portion abutting the extension ring when the connecting device is assembled together. In particular, the contact portion may have a central opening of the electrical contact element.

[0022] The contact portion of the electrical contact element is preferably configured to slidably receive an extension collar. In particular, if applicable, the contact portion is preferably configured for insertion and slidably disposed between the inner walls of the extension collar and the clamping contact collar.

[0023] In the assembled state, the electrical contact element with the contact portion can protrude into the clamping contact ring and press against the inner wall by the expanding ring.

[0024] Particularly preferably, the contact portion is substantially formed as a hollow cylinder. The central opening of the electrical contact element is located within the hollow cylinder. When the connecting devices are assembled, the contact portion preferably covers more than half of the hollow cylindrical socket in the circumferential direction. This allows for the maximum possible contact area between the contact portion and the rest of the connecting device. A large contact area is advantageous for achieving mechanical stability of the connection and good electrical conductivity between the electrical contact element and the rest of the connecting device.

[0025] To improve the mechanical stability and electrical conductivity between the components of the connecting device, at least one friction structure may be provided on the outer surface of the expansion ring, the inner wall of the clamping contact ring (if applicable), and / or the surface of the electrical contact element (if applicable), at least in their contact portions. The friction structure can be obtained by structuring away from smooth surfaces. In particular, the friction structure may have contact protrusions, ribs, dots, knurling, or rough surfaces.

[0026] The electrical contact element may have at least one longitudinal slot, similar to the expansion collar, at its contact portion, to facilitate expansion. The longitudinal slot may open toward one end of the electrical contact element or the expansion collar, thereby facilitating the expansion of the electrical contact element.

[0027] The connection device according to the invention may further include a conductor rail or another electrical conductor having a through hole, wherein an extension collar is connected to the conductor rail protruding through the through hole and inserted into the central opening of the electrical contact element.

[0028] The connection device with the conductor rail may further include a clamping contact ring that is at least partially inserted into a through hole from a first side of the conductor rail, wherein an extension ring protrudes through the through hole from a second side of the conductor rail opposite to the first side into the clamping contact ring.

[0029] In order to fix the position of the extension ring relative to the conductor rail, the extension ring may be provided with a stop for abutting against the conductor rail, especially on its second side.

[0030] When the electrical contact element is connected to the rest of the connecting device, it can initially be positioned without force relative to the expansion collar. If the clamping contact collar is part of the connecting device, the electrical contact element can be moved without force, at least in the axial direction, until it reaches the desired position. Only in this way can a radial force be generated on the electrical contact element by expanding the expansion collar, which clamps the expansion collar to the electrical contact element and / or the electrical contact element between the expansion collar and the clamping contact collar.

[0031] The invention will now be explained in more detail with reference to the accompanying drawings, by way of exemplary advantageous embodiments. Depending on the characteristics of the connection device according to the invention necessary for a particular application, the combinations of features exemplarily shown in the embodiments may be supplemented by other features as explained above. Furthermore, also as explained above, if the effect of a single feature is not important in a particular application, that feature may be omitted from the described embodiments. In the drawings, the same reference numerals are always used for elements having the same function and / or the same structure. Attached Figure Description

[0032] The following is shown:

[0033] Figure 1 A first advantageous embodiment of the connecting device according to the invention is shown in exploded view;

[0034] Figure 2 Shown in perspective Figure 1 The connecting device;

[0035] Figure 3 shows a longitudinal cross-section. Figure 1 The connecting device;

[0036] Figure 4 shows a cross-sectional view. Figure 1 The connecting device;

[0037] Figure 5 shows a second advantageous embodiment of the connecting device according to the invention in an exploded view;

[0038] Figure 6 shows the connection device of Figure 5 in a longitudinal section;

[0039] Figure 7 The connecting device in Figure 5 is shown in cross-section;

[0040] Figure 8 A third advantageous embodiment of the connecting device according to the invention is shown in perspective view;

[0041] Figure 9 Shown in longitudinal section Figure 8 The connecting device;

[0042] Figure 10 Shown in perspective Figure 8 The receiving element of the connection device;

[0043] Figure 11 Shown in longitudinal section Figure 8 The clamping element of the connecting device; and

[0044] Figure 12 A cross-sectional view is shown. Figure 8 The connecting device. Detailed Implementation

[0045] The following reference Figure 1 Sections 4 to 4 describe a first advantageous embodiment of the connecting device 1 according to the invention. The connecting device 1 of the first embodiment has an expansion collar 3 and an expansion element 5 that can be inserted into the expansion collar.

[0046] Preferably, but not necessarily, the clamping contact ring 7 is also part of the connecting device 1. Furthermore, the electrical contact element 9 and / or the electrical conductor 11 may also be part of the connecting device 1. By way of example only, the electrical conductor 11 is shown in the figure as conductor rail 13.

[0047] The connecting device 1 is used for mechanical fastening, and preferably, it is also used to establish a conductive connection between the electrical contact element 9 and the electrical conductor 11.

[0048] The extension ring 3 has an overall elongated hollow cylindrical shape and extends along the longitudinal axis 15. Along the longitudinal axis 15, the extension ring 3 has a conductor-side end 17 and a contact-side end 19.

[0049] At its contact end 19, the expansion collar 3 has two longitudinal slots 21. The two longitudinal slots 21 extend from the contact end 19 parallel to the longitudinal axis 15 into the expansion collar 3, such that the expansion collar 3 is open in the radial direction toward the contact end 19 through the longitudinal slots 21. Two contact pressure elements 23 are formed by the two longitudinal slots 21, which may be offset from each other in the radial direction.

[0050] Inside the expansion collar is an expansion element socket 25 for receiving the expansion element 5. Within the expansion element socket 25, an expansion collar 3 with internal threads 27 is provided. The expansion element 5 is correspondingly provided with complementary external threads 29.

[0051] The extension element 5 can be inserted into the extension collar 3 or its extension element socket 25 along the insertion direction 31. The insertion direction 31 extends parallel to the longitudinal axis 15 from the conductor-side end 17 toward the contact-side end 19.

[0052] If the expansion element 5, which can be configured as screw 33, is inserted into the expansion collar 3 and actuated in a manner that the two threads 27 and 29 interact, the two contact pressure elements 23 can move away from each other. In other words, screwing in the screw 33 can cause the expansion collar 3 to expand.

[0053] To increase the expansion of the extension ring 3, the extension element socket 25 may taper gradually along the insertion direction 31. Alternatively or additionally, the extension element 5 may expand against the insertion direction 31, at least in the region of the external thread 29.

[0054] At its conductor-side end 17, the extended collar 3 is provided with a flange 35. The flange 35 may abut the electrical conductor 11 to define the position of the extended collar 3 relative to the electrical conductor 11.

[0055] Furthermore, the extension ring 3 may have knurling 37 in the area adjacent to the flange 35, and the extension ring 3 may be pressed against the clamping contact ring 7 by the knurling 37. In addition to being mechanically fastened to the clamping contact ring 7, the knurling 37 may also be used to prevent the extension ring 3 from rotating when the extension element 5 rotates.

[0056] In an alternative embodiment without clamping contact ring 7, knurling 37 may also interact with the inner wall of through hole 39 in electrical conductor 11.

[0057] The clamping contact ring 7 has an integral hollow cylindrical shape. The clamping contact ring 7 is configured such that when the extension ring 3 is inserted into the clamping contact ring 7, it is arranged coaxially with the extension ring 3.

[0058] The clamping contact ring 7 has a conductor portion 41 and a contact portion 43, which are adjacent to each other along the longitudinal axis 15. In the assembled state, the longitudinal axis of the clamping contact ring 7 corresponds to the longitudinal axis 15 of the extension ring 3.

[0059] The conductor portion 41 is used to connect to the electrical conductor 11, particularly to the conductor rail 13. The outer diameter 45 of the clamping contact ring 7 in the conductor portion 41 is designed such that the conductor portion 41 can be inserted into the through hole 39 of the conductor 11, preferably forming a press fit.

[0060] The inner diameter 47 of the clamping contact ring 7 in the conductor portion 41 is preferably determined such that the expansion ring 3 can be accommodated in the portion. In particular, the expansion ring 3 can be inserted into the conductor portion 41 to form a press fit in the clamping contact ring 7.

[0061] If the extended collar 3 is provided with knurling 37, the extended collar 3 forms a positive connection and / or frictional connection with the clamping contact collar 7 at least in the area of ​​knurling 37.

[0062] In the contact portion 43, the outer diameter 49 of the clamping contact ring 7 can be larger than the outer diameter 45 in the conductor portion 41.

[0063] Due to the different outer diameters 45 and 49, a step 51 can be formed between the two portions 41 and 43. The step 51 can be used to define the position of the clamping contact ring 7 relative to the conductor 11. In other words, the clamping contact ring 7 can be inserted from the first side 53 of the conductor 11 into the through hole 39 until it abuts the conductor 11 through the step 51 or through the contact portion 43 on the first side 53.

[0064] Therefore, the extension collar 3 can be inserted into the through hole 39 or clamped into the contact collar 7 from the second side 55 opposite to the first side 53 until the flange 35 rests against the second side 55 of the conductor. The flange 35 represents the stop 56 of the extension collar 3.

[0065] In the contact portion 43, the clamping contact ring 7 preferably has an inner diameter 57 that is larger than the inner diameter 47 in the conductor portion 41. In other words, at least in the state where the expansion ring 3 has not yet expanded, the inner diameter 57 is larger than the outer diameter 59 of the expansion ring 3.

[0066] Since the inner diameter 57 of the clamping contact ring 7 in the contact portion 43 is larger than the outer diameter 59 of the expansion ring 3, at least in the contact portion 43, a contact socket 63 for the electrical contact element 9 is formed between the inner wall 61 of the expansion ring 3 and the clamping contact ring 7, which can be accessed from the outside.

[0067] The contact socket 63 preferably has an annular cross-section or a hollow cylindrical shape.

[0068] As the expansion collar 3 expands, it expands toward the inner wall 61. In other words, the two contact pressure elements 23 move away from each other. The cross-section of the contact socket 63 thus decreases. As the contact element 9 is inserted into the contact socket 63, the contact element 9 is thus clamped between the expansion collar 3 and the inner wall 61 of the clamping contact collar 7.

[0069] The electrical contact element 9 has a contact portion 65 through which it can be inserted into the clamping contact ring 7, and in particular into the contact socket 63.

[0070] At least in the contact portion 65, the contact element 9 is preferably hollow cylindrical, such that it is formed to complement the contact socket 63.

[0071] A hollow cylinder surrounds the central opening 67 of the contact element 9. An extension collar 3 can be inserted into the central opening 67 of the electrical contact element 9. In principle, this is also possible without clamping the contact collar 7.

[0072] When the electrical contact element 9 is inserted into the contact socket 63 with its contact portion 65, the electrical contact element 9 is disposed between the inner wall 61 of the expansion sleeve 3 and the clamping contact sleeve 7 when viewed in the radial direction.

[0073] As long as the extending element 5 is not fully inserted into the extending collar 3, the contact element 9 can move along the longitudinal axis 15. The contact element 9 is not clamped until the extending collar 3 extends.

[0074] In particular, in embodiments with clamping contact ring 7, contact element 9 is also provided with longitudinal slot 69, so that contact element 9 can also open to follow the movement of expansion ring 3 and be pressed against inner wall 61.

[0075] Particularly preferably, the contact element 9 is provided with two longitudinal slots 69. The two longitudinal slots 69 pass through the central opening 67 and are radially opposite each other.

[0076] The electrical contact element 9 may have a connection portion 71, as it may have any shape suitable for being accommodated and / or electrically contacting the contact element 9 in, for example, a plug or another component.

[0077] Between the connecting portion 71 and the contact portion 65, there may be a transition portion 73, wherein the shape of the contact element 9 in the connecting portion 71 is incorporated into the shape of the contact element 9 in the contact portion 65.

[0078] The electrical contact element 9 has a friction structure 77 in its contact portion 65, at least on its outer surface 75. The friction structure 77 is formed by a plurality of outwardly facing protrusions 79. The protrusions 79 can form defined contact points for contacting the inner wall 61 of the clamping contact ring 7 when the expansion ring 3 is opened and the contact element 9 is pressed against the inner wall 61.

[0079] Alternatively or additionally, the surface 81 of the inner wall 61 may be provided with a friction structure 77.

[0080] A second advantageous embodiment of the connecting device 1 according to the invention will now be described with reference to Figures 5 to 7. For the sake of brevity, only the connection device 1 described above will be discussed. Figure 1 The differences are as described in the embodiment of Figure 4.

[0081] In the second embodiment, the extended collar 3 has a friction structure 77 on its outer surface 83, at least in its expandable region, i.e., at the level of the internal thread 27.

[0082] The friction structure 77 extends from the contact-side end 19 to the conductor-side end 17, but does not extend to the end of the longitudinal slot 21. The friction structure 77 is only required in the area where the extended collar 3 presses against the contact element 9.

[0083] By way of example only, the friction structure 77 is shown as knurled 85. As an alternative to knurled 85, the friction structure 77 may be formed as a plurality of contact protrusions 79, as in the contact element 9 of the first embodiment or in any other structure.

[0084] In the second embodiment, the contact element 9 is formed without the friction structure 77. Alternatively, the contact element 9 itself may be provided with the friction structure 77. In particular, the contact element 9 may have the friction structure 77 on its outer surface 75. According to another alternative, the surface 81 of the inner wall 61 of the clamping contact ring 7 may be provided with a friction structure.

[0085] The following reference Figures 8 to 12 A third advantageous embodiment of the connecting device 1 according to the invention will be described. Again, for the sake of brevity, only the differences from the foregoing embodiments will be discussed.

[0086] The third embodiment of the connecting device 1 differs from the previous embodiments in that it has a two-piece extension collar 3. The extension collar 3 can be used in the same manner as the extension collar 3 in the previous embodiments. However, the manufacture of the two-piece extension collar 3 can be simplified due to its two-piece nature.

[0087] The two-piece extension collar 3 consists of a clamping element 87 and a receiving element 89. The receiving element 89 can be received in the clamping element 87. Once the receiving element 89 is inserted into the clamping element 87, the two-piece extension collar 3 is assembled.

[0088] The clamping element 87 has an external shape that is substantially the same as the shape of the extended collar 3 in the aforementioned embodiment.

[0089] The clamping element 87 is not provided with an internal thread. Instead, an internal thread 27, designed to complement the external thread 29 of the expansion element 5, exists inside the receiving element 89. The receiving element 89 therefore has an expansion element socket 25.

[0090] The receiving element 89 itself is ring-shaped and has a generally hollow cylindrical shape. The receiving element 89 can be received within a clamping element 87, which has a shoulder 91 extending along the circumferential direction of the clamping element 87 to define the position of the receiving element 89 relative to the longitudinal axis 15. In other words, the shoulder 91 provides a seat for the receiving element 89.

[0091] To prevent the receiving element 89 from rotating when the extension element 5 is actuated, the receiving element 89 can be received in the clamping element 87 in an anti-rotation manner. For this purpose, the clamping element 87 has a protrusion 95 on its outer side 93, which can be accommodated in a complementary-shaped socket 97 in the clamping element 87.

[0092] With the two-piece extension ring 3 assembled together, the protrusion 95 extends radially into the receiving socket 97. Because the protrusion 95 abuts against the edge 99 that defines the receiving element 97 when the receiving element 89 rotates, the receiving element 89 cannot rotate within the clamping element 87.

[0093] The protrusion 95 is shown as an example only, as a rib extending along the longitudinal axis 15. The protrusion 95 may also have any other shape suitable for interacting with the receiving socket 97 to prevent the receiving element 89 from rotating in the clamping element 87.

[0094] To facilitate the expansion of the two-piece extension ring 3, the receiving element 89 is preferably at least partially tapered.

[0095] For example, the receiving element 89 may have an external cross-section that gradually increases from the bottom side 101 to the top side 103. When assembled, the receiving element 89 can abut against the shoulder 91 through the bottom side 101, and the top side 103 is opposite to the bottom side along the longitudinal axis 15.

[0096] Alternatively or additionally, the clamping element 87 may have an internal cross-section that tapers gradually from the contact-side end 19 toward the shoulder 91. Actuation of the extension element 5 pulls the receiving element 89 into the clamping element 87, causing the clamping element 87 to open. As a result, as in the foregoing embodiment, the electrical contact element 9 presses against the inner wall 61 of the clamping contact collar 7.

[0097] List of reference numerals

[0098] 1. Connecting device

[0099] 3 Extended rings

[0100] 5 expansion components

[0101] 7 Clamping contact ring

[0102] 9 Electrical contact elements

[0103] 11 Electrical conductors

[0104] 13 conductor rails

[0105] 15 Longitudinal axis

[0106] 17 Conductor side end

[0107] 19 Contact side end

[0108] 21 longitudinal slots

[0109] 23 Contact pressure element

[0110] 25 expansion component sockets

[0111] 27 internal thread

[0112] 29 external thread

[0113] 31 Insertion Direction

[0114] 33 screws

[0115] 35 flange

[0116] 37 Knurling

[0117] 39 through holes

[0118] 41 Conductor section

[0119] 43 Contact Part

[0120] 45 outer diameter of conductor section

[0121] 47. Inner diameter of the conductor section

[0122] 49 Outer diameter of the contact part

[0123] 51 steps

[0124] 53 First side

[0125] 55 Second side

[0126] 56 stop parts

[0127] 57 Inner diameter of the contact part

[0128] 59 Outer diameter of the extended ring

[0129] 61 Inner Wall

[0130] 63 contact socket

[0131] 65 contact parts

[0132] 67 Center Opening

[0133] 69 longitudinal slots

[0134] 71 Connection Part

[0135] 73 Transition Section

[0136] 75 surface

[0137] 77 Friction Structure

[0138] 79 protrusions

[0139] 81 Surface of the inner wall

[0140] Surface of 83 extended ring

[0141] 85 Knurl

[0142] 87 clamping elements

[0143] 89 Receiving Components

[0144] 91 Shoulder

[0145] 93 outer side

[0146] 95 protrusion

[0147] 97 socket

[0148] 99 Edge

[0149] 101 bottom side

[0150] 103 Top Side

Claims

1. A connection device (1) for securing an electrical contact element (9) having a central opening (67) to a conductor rail (13), the connection device (1) comprising an expansion collar (3) and an expansion element (5) insertable into the expansion collar (3), wherein the expansion collar (3) is designed to be slidably inserted into the central opening (67) of the electrical contact element (9), and wherein the expansion collar (3) expands to clamp the electrical contact element (9) when the expansion element (5) is fully inserted into the expansion collar (3); A clamping contact ring (7) is configured to receive the extended ring (3) and the electrical contact element (9); Conductor rail (13) having through hole (39), wherein, The extended collar (3) is connected to the conductor rail (13) protruding through the through hole (39) and inserted into the center opening (67) of the electrical contact element (9), the clamping contact collar (7) is inserted into the through hole (39), and the extended collar (3) protrudes through the through hole (39) into the clamping contact collar (7); The clamping contact ring (7) has a conductor portion (41) configured to be inserted into a through hole (39) to connect to the conductor rail (13).

2. The connecting device (1) according to claim 1, wherein, When the extension element (5) is fully inserted into the extension collar (3), the extension collar (3) extends toward the inner wall (61) of the clamping contact collar (7).

3. The connecting device (1) according to claim 1 or 2, wherein, The extension element (5) is conical or wedge-shaped.

4. The connecting device (1) according to claim 1 or 2, wherein, The extension ring (3) has an extension element socket (25) configured to receive the extension element (5).

5. The connecting device (1) according to claim 4, wherein, The expansion element socket (25) gradually tapers along the insertion direction (31) of the expansion element (5).

6. The connecting device (1) according to claim 4, wherein, The extension collar (3) consists of two parts and includes a clamping element (87) and a receiving element (89) disposed in the clamping element (87) and having the extension element socket (25).

7. The connecting device (1) according to claim 6, wherein, The receiving element (89) is held in the clamping element (87) in a rotation-resistant manner.

8. The connecting device (1) according to claim 1 or 2, wherein, The extension ring (3) is provided with an internal thread (27), and the extension element (5) is provided with an external thread (29) that is complementary to it.

9. The connecting device (1) according to claim 1 or 2 further includes an electrical contact element (9) having a contact portion (65) configured to be connected to the extended collar (3), the contact portion (65) being adjacent to the extended collar (3) in the assembled state of the connecting device (1).

10. The connecting device (1) according to claim 9, wherein, The contact portion (65) is basically a hollow cylinder.

11. The connecting device (1) according to claim 1 or 2, wherein, The surface (83) of the extended collar (3), the inner wall (61) of the clamping contact collar (7), if available, and / or the surface (75) of the electrical contact element (9), if available, are provided with at least one friction structure (77) in at least its contact portion (65).

12. The connecting device (1) according to claim 1 or 2, wherein, The extended collar (3) and / or the electrical contact element (9), if available, are provided with at least one longitudinal slot (21, 69).

13. The connecting device (1) according to claim 1, wherein the clamping contact ring (7) is inserted into the through hole (39) at least partially from the first side (53) of the conductor rail (13), and the extension ring (3) protrudes into the clamping contact ring (7) from the second side (55) of the conductor rail (13) opposite to the first side (53) through the through hole (39).

14. The connecting device (1) according to claim 1, wherein, The extended collar (3) is provided with a stop (56) for abutting against the conductor rail (13).

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