CONTACT SPRING ARRANGEMENT FOR SELF-LOCKING CONTACT OF AN ELECTRICAL CONDUCTOR

Description

[0001] The invention relates to a contact spring arrangement for self-locking contact of a conductor of an electrical conductor, comprising a support wall formed of a conductive material, a contact spring which has a base leg held stationary with respect to the support wall and a clamping leg which together with the support wall forms a plug receptacle for the conductor that tapers in the insertion direction.

[0002] An example of such a contact spring arrangement is described in DE 20 2006 009 460 U1. The support wall can be part of a conductive structure, such as a busbar or a connector contact. To bring the conductor's core into contact with this structure, a stripped end of the core (e.g., a copper wire) is inserted into the receptacle. The end of the core slides onto the flank of the clamping arm and deflects this arm. Due to the elastic restoring force of the spring, a gripping edge formed at the free end of the clamping arm engages the circumferential surface of the copper core. If an attempt is now made to withdraw the conductor, the force exerted by the core on the gripping edge tends to pivot the clamping arm further towards the support wall and press it even more firmly against the core, thus holding the core in position in a self-locking manner.

[0003] To release the contact, a release mechanism is moved in the insertion direction, causing an actuating arm to run onto the flank of the clamping leg and bend it back. This releases the conductor's core, allowing the conductor to be withdrawn from the socket.

[0004] In the known arrangement, the base leg of the contact spring is riveted to a part of the busbar, so that the contact spring is held securely in position even under the influence of high tensile forces.

[0005] A contact spring arrangement according to the preamble of claim 1 is known from DE 20 2009 013 335 U1.

[0006] The object of the invention is to create a contact spring arrangement that is easier to assemble.

[0007] This problem is solved according to the invention with the features specified in claim 1.

[0008] Inserting and securing the contact spring in the support wall structure can be accomplished with a simple linear movement. The retaining leg is inserted into the receiving slot until the locking lugs automatically engage with the mating contours. This assembly process can therefore be performed with a simple assembly machine that does not require a complex motion scheme and can thus operate at a high cycle rate. The locking lugs and mating contours can be designed to withstand the pull-out forces expected during normal operation, which tend to pull the retaining leg back out of the receiving slot. Despite the simple assembly process, a secure fixation of the contact spring can therefore be achieved.

[0009] Advantageous embodiments and further developments of the invention are specified in the dependent claims.

[0010] In one embodiment, the support wall is part of an electrically conductive structure that also forms the receiving shaft for the retaining leg of the contact spring. Thus, the locking mechanism simultaneously improves the electrical contact between the contact spring and the conductive structure.

[0011] According to the invention, the receiving shaft is formed by two parallel grooves into which two locking arms of the fork-shaped retaining leg engage. The grooves can be easily produced by machining. The counter contours can be formed, for example, by an end face in which the grooves terminate. In other embodiments, the receiving shaft and the counter contours can also be formed by forming the metal body, for example, by producing at least part of the conductive structure from a profile strand with a corresponding groove profile.

[0012] The contact spring can be manufactured simply and efficiently as a stamped and bent part. The locking lugs can then be produced in any desired shape in a single stamping operation. For example, the locking lugs can be designed as barbs, thus enabling a positive-locking or self-locking connection of the retaining leg in the receiving shaft.

[0013] In one embodiment, the insertion direction in which the retaining leg is inserted into the receiving shaft is parallel to the insertion direction of the plug receptacle for the conductor's core. Frequently, the contact spring assembly also includes an actuator movable in this insertion direction, which serves to bend the clamping leg of the contact spring away from the conductor's core, thus releasing the clamp when the core is to be disconnected. In this case, further rationalization of automated production is achieved because the movements during the assembly of the actuator and the assembly of the contact springs occur in the same direction.

[0014] In another embodiment, the insertion direction of the retaining arm is perpendicular to the insertion direction of the plug receptacle. In this case, the tensile forces acting on the contact spring when attempting to pull the conductor wire out of the plug receptacle against the clamping force are positively absorbed by the engagement of the retaining arm in the receptacle shaft, so that only a relatively weak locking action is sufficient to secure the retaining arm.

[0015] The following are examples of implementation explained in more detail with reference to the drawing.

[0016] They show: Fig. 1 a perspective view of a contact spring arrangement according to the invention; Fig. 2 a perspective view of an electrically conductive support structure of the contact spring arrangement; Fig. 3 a section through the support structure in section plane III in Fig. 2 Fig. 4 shows an axial section through a contact spring; Fig. 5 shows the contact spring in a left-hand view. Fig. 4 Figs. 6 to 8 show different stages in the insertion of the contact spring into the support structure; Fig. 9 shows an axial section through a contact spring according to another embodiment; Fig. 10 shows a side view of part of a support structure for the contact spring. Fig. 9 ; Fig. 11 an exploded view of the contact spring and the support structure according to Fig. 10 , wherein the supporting structure in a section in plane XI-XI in Fig. 10 is shown; and Fig. 12 the contact spring in its position locked to the support structure.

[0017] The in Fig. 1 The contact spring assembly shown comprises a metal contact spring 10 and an electrically conductive support structure 12, which in the example shown forms a socket contact 14 and an axially adjoining cage 16, also referred to as a busbar. The contact spring 10 has a clamping leg 18 and a base leg 20, which is connected to the clamping leg 18 via a U-shaped bend and transitions at the opposite end into a flat retaining leg 22.

[0018] The contact spring 10 is held to the cage 16 by its retaining leg 22 such that the clamping leg 18 projects obliquely into the interior of the cage and forms a plug-in receptacle 26 for a conductor 28 of an electrical conductor with a support wall 24 of the cage opposite the contact spring. The conductor 28 is thus mechanically fixed in the cage and electrically connected to the support structure 12. The conductor 28 is held clamped between the clamping leg 18 and the support wall 24, and because the clamping leg engages the conductor obliquely, the conductor is self-locking in the cage when a tensile force acts on the conductor 28 in the extension direction.

[0019] The cage 16 forms a receiving shaft 30 on the side opposite the support wall 24, which extends in the insertion direction of the plug receptacle 24 and into which the fork-shaped retaining leg 22 of the contact spring 10 is inserted from above. Fig. 1 The receiving shaft 30 is formed by two parallel grooves in the outer surfaces of the cage 16, which are bounded on the side facing away from the insertion point by a bracket 32. This bracket is connected to the main part of the cage 16 only via a web 34, which extends through a slot 36 between the fork arms of the retaining leg 22. The fork arms of the retaining leg 22 each form two opposing locking lugs 38 at their free ends, which engage under the web 34 and thus lock the retaining leg 22 into the receiving shaft 30.

[0020] In Fig. 2 The supporting structure 12 is shown without the contact spring 10, so that the receiving shaft 30 is more clearly visible.

[0021] Fig. 3 shows a cross-section of cage 16 in the Fig. 2 The section plane III, indicated by a dashed line, reveals the exact cross-sectional shape of the bracket 32, the web 34, and the grooves forming the receiving shaft 30. Optionally, the cage or the entire supporting structure can be manufactured from a single profile strand, which is described in Fig. 3 The profile shown is...

[0022] In Fig. 4 The contact spring 10 is shown in an axial section, while Fig. 5 Figure 1 shows a front view of the base leg 20 and the retaining leg 22 of the contact spring. The outline of the slot 36 and the locking lugs 38, which are designed as barbs, is shown in Figure 2. Fig. 5 to recognize.

[0023] Fig. 6 Figure 1 shows an enlarged view of the contact spring 10 and the support structure 12 in a state before the retaining leg is inserted into the receiving shaft. The support structure 12 is shown here in a section in a section plane that passes through the web 34.

[0024] Fig. 7 Figure 1 shows the contact spring 10 and the support structure 12 in the state in which the retaining leg 22 enters the receiving shaft 30 with its free end and the flanks of the locking lugs 38 run onto the upper edges of the web 34. At this stage, the (in Fig. 7 The (not visible) clamping legs of the contact spring are already inserted into the plug receptacle 24, thus guiding the contact spring and centering it with its slot 36 on the bridge 34. When the contact spring 10 is pressed further downwards, a slightly greater resistance must be overcome, as the fork arms of the retaining leg 22 are elastically spread by the bridge 34 until the locking lugs 38 can slide over the bridge.

[0025] Fig. 8 Figure 1 shows the final state in which the fork arms of the retaining leg 22 have elastically springed back to their original position and now engage the underside of the bridge 34. This underside of the bridge thus forms a counter contour for the locking lugs 38. This counter contour, as well as the adjacent upper surfaces of the locking lugs 38, run perpendicular to the insertion direction, so that the retaining leg 22 is positively locked in its receiving slot when an upward pull-out force acts on the contact spring.

[0026] In Fig. 9 bis 12 A modified embodiment of the contact spring arrangement is shown.

[0027] Fig. 9 Figure 1 shows an axial section through a contact spring 10', which differs from the previously described contact spring 10 in that it has an extended base leg 20' which transitions at the free end into a retaining leg 22' angled at a right angle to the side of the clamping leg 18.

[0028] Fig. 10 shows the upper part of an associated support structure 12'. This support structure forms a cage 16' in the area of ​​the lower end. 5 a horizontally extending receiving shaft 30' for the retaining leg 22'.

[0029] How Fig. 11 As shown, the upper part of the cage 16' is connected to the lower part of the cage, which also forms the upper end of the socket contact 14, only by a short cylindrical web 34'. The retaining leg 22' is again fork-shaped and has a slot 36' with two circular segment-shaped protrusions 40 that are complementary to the circumferential surface of the web 34'. The ends of these protrusions 40, located towards the free end of the retaining leg, form locking lugs 38'.

[0030] When the retaining leg 22' is inserted into the receiving shaft 30, as shown in Fig. 12As shown, the locking lugs 38' engage behind the circumferential surface of the web 34, which thus forms a counter contour for the locking lugs.

Claims

1. Contact spring assembly for the self-locking contacting of a wire (28) of an electrical conductor, having a supporting wall (24) formed from a conductive material, a contact spring (10; 10'), which has a base leg (20; 20') held stationary in relation to the supporting wall and a clamping leg (18), which, together with the supporting wall (24), forms a plug-in receptacle (26) for the wire (28) of the conductor, said receptacle tapering in the insertion direction, wherein the base leg (20; 20') of the contact spring merges into a holding leg (22; 22'), which is inserted into a receiving shaft (30; 30') stationary in relation to the supporting wall (24) and has two latching projections (38; 38'), which project in opposite directions transversely to the base leg and are latched with mating contours (34; 34') on the walls of the receiving shaft, wherein the receiving shaft (30; 30') is formed by two parallel grooves, which are open at least at one end, and the holding leg (22; 22') of the contact spring is of fork-shaped design, characterized in that the mating contours for the latching projections (38; 38') are formed on a web (34; 34') which extends through a slot (36; 36') formed between the fork arms of the holding leg (22; 22').

2. Contact spring assembly according to Claim 1, in which the receiving shaft (30; 30') is formed in an electrically conductive supporting structure (12; 12'), which also forms the supporting wall (24).

3. Contact spring assembly according to either of the preceding claims, in which the receiving shaft (30) extends parallel to the insertion direction of the plug-in receptacle (26).

4. Contact spring assembly according to Claim 5, in which the latching projections (38) are designed as barbs.

5. Contact spring assembly according to Claim 1, in which the receiving shaft (30') extends at right angles to the insertion direction of the plug-in receptacle (26).

6. Contact spring assembly according to Claims 1 and 5, in which the slot (36') of the holding leg (22') is locally widened by two mutually opposite indentations (40), and the latching projections (38') are formed at one end of each of these indentations.