PROTECTIVE TOUCH PIN

Description

[0001] The invention relates to a touch protection pin for a contact sleeve, comprising a shaft and an end tip. The invention further relates to a contact carrier with a touch protection pin and an electrically conductive, detachable connector with at least one such contact carrier.

[0002] Connectors in a wide variety of designs and variants are used to establish or create detachable electrically conductive connections. Connector solutions are available in a multitude of different constructions, for example, with regard to the number of poles, electrical power ratings, and the ability to withstand various external influences such as humidity, temperature, corrosive media, or mechanical stresses.

[0003] Depending on the installation or environmental conditions, application, wiring situation, etc., different requirements may apply to the connector or detachable contact devices. Connectors, especially those used in high-power applications, must meet the highest standards of safety, reliability, and personal protection. This applies not only to the intended use of the connectors but also, and perhaps more importantly, to situations during assembly, before connecting the plugs, and, last but not least, to accidental disconnection or improper handling in general.

[0004] To eliminate the risk to people or operating and assembly personnel and to meet the highest safety requirements, plug connections are known whose current-carrying elements and contact elements are insulated and / or provided with touch protection, so that contact with the current-carrying components is prevented both when plugged in and unplugged, as well as in assembly situations.

[0005] DE 10 2018 127 720 B3 presents a high-current connector comprising an insulating body. The insulating body has a polarization element to determine the orientation of the mating connector on the insulating body, as well as a coding element to prevent incorrect mating. In particular, the coding element can effect a specific coding through its relative position to the polarization element. For electrical safety reasons, the plug contact, especially the pin contact at the free end of its mating area, can have touch protection made of an electrically insulating material, such as plastic. A potential problem with this touch protection solution is the reduced contact area of ​​the contact elements.

[0006] A touch-protected electrical connector is also mentioned in DE 10 2018 205 951 A1. Starting with a housing containing battery cells, a connector is proposed that corresponds to the battery housing and can be inserted into plug openings, allowing voltage to be tapped. In one variant, each plug opening is equipped with touch protection. This further increases safety when handling the housing during maintenance work and the like. The touch protection is provided by the clear opening of the plug opening and / or by a locking mechanism, whereby the clear opening of each plug opening is selected such that a service technician's fingers cannot pass through the plug opening and touch a plug contact located below it.A locking mechanism can be designed as a spring-loaded cover that automatically closes the plug opening, similar to a child safety lock. The disadvantages of this solution include not only the limited accessibility due to the reduced opening width of the plug connection, but also the general vulnerability and reduced reliability of the locking mechanism with its moving parts. The cost-effectiveness is also a disadvantage due to the expense of the moving parts.

[0007] DE 20 2017 101 673 U1 discloses a protective sleeve for live contact elements. The sleeve, in its extended position, surrounds the live plug contact section, preventing accidental contact. It is mounted in an insulating housing so that it is longitudinally displaceable, i.e., movable in the plugging direction. The sleeve incorporates linear guide elements mounted in a linear guide arrangement on the insulating housing side, allowing longitudinal movement within the guide elements. A compression spring located within the insulating housing exerts force on the sleeve. This spring is supported by a part of the insulating housing, a busbar, or a connecting section. The compression spring thus pre-tensions the sleeve in the plugging direction.This touch protection solution is expensive due to the large number of moving parts and is not reliable with regard to the movement mechanism that is essential for the protective function.

[0008] WO 2013 / 091990 A1 describes touch protection for current-carrying connecting elements in an arrangement with a plug pin and a shield. The plug pin is provided with touch protection in the form of a non-conductive protective cap. Furthermore, the non-conductive shield and the plug pin area are separated by a slot opening.

[0009] The technical teaching presented in publication DE 10 2018 109 557 A1 relates to a touch guard for a plug-side electrical connector with at least two flat electrical contact elements arranged parallel to each other, which extend in a housing of the connector in the plug-in direction of the connector for connection with a corresponding socket-side connector towards an opening of the housing. A plastic tip is formed at one end of a contact area of ​​the contact elements, and at least one dome-shaped touch guard is also provided in the housing, which extends adjacent to the contact elements in the plug-in direction and has a predetermined height that corresponds at least approximately to the height of the contact area of ​​the contact elements.The protective body can have a height such that it extends beyond the contact area of ​​the contact elements by a predetermined amount.

[0010] DE 20 2014 011 405 U1 shows a touch protection solution on the male side of a plug connection with an electrically conductive pin contact element, the touch protection solution of which is formed by a touch protection device that partially covers the pin contact element.

[0011] Further solutions for a touch protection pin are known from the documents DE 10 2015 002 251 A1, WO 96 / 29761 A1 and EP 3 570 382 A1.

[0012] If touch protection solutions are required for circular connectors, such as socket contacts, lamellar sleeves, or contact sleeves (so-called Radsok elements), these are usually achieved through the geometry of the connector housing. If this alone is insufficient, touch protection pins can be used. These are centrally located pins extending within the socket contact and projecting axially beyond it. This prevents a user from reaching and touching the live inner surface of the socket contact. The corresponding contact pin for establishing the electrically conductive connection with the socket must have an axial bore into which the touch protection pin fits when the connector is mated.

[0013] Such a touch protection pin is either made of plastic or metal with a plastic tip. These pins are typically pressed or screwed into the connector housing. Designs are also conceivable where the touch protection pin is integrated as a component of a connector cover or the connector housing itself.

[0014] Common touch protection solutions for circular connectors, in the form of touch protection pins screwed into the connector housing, can be removed because the screw-in connection is detachable. If a touch protection pin is removed, it is possible to touch the live parts of the socket contact, lamellar sleeve, or contact sleeve and receive an electric shock. If the touch protection pin is an integral part of a connector cover or housing manufactured by injection molding, not only is the injection mold very complex, but the touch protection pin can also break off during contact sleeve assembly, as the contact sleeve typically has to be pressed into the connector housing.If the touch protection pin is designed as an integral part of an injection-molded connector cover or connector housing based on a metallic material, the touch protection pin must, for example, be equipped with an insulating element at its tip or at least partially coated with a non-conductive material on its outer surface.

[0015] The object of the invention is to further develop and improve existing touch protection solutions for plug connections and connector systems in the form of touch protection pins in such a way that the touch protection pin can be mounted easily and reliably, high touch protection safety is ensured, and the disadvantages occurring in the prior art are at least partially reduced.

[0016] To solve this problem, the invention proposes a touch protection pin according to claim 1, which has a round flange at one end. The touch protection pin is clamped by its flange between the socket contact, lamellar sleeve, and contact sleeve in the receiving bore of the contact sleeve, and the shaft of the pin projects through the inside of the contact sleeve. The solution according to the invention not only provides a very simple and cost-effective design, but also ensures safe and reliable assembly in a single operation using only one pressing tool, in conjunction with pressing the socket contact, lamellar sleeve, and contact sleeve into the receiving bore. The receiving bore can be located within a contact carrier, a connector housing, or a housing cover of the connector.

[0017] After the socket contact, lamellar sleeve, and contact sleeve are pressed in together with the touch protection pin in a single operation, the latter can only be removed by destructive means, as there is no detachable connection as with screw-in solutions. The touch protection pin with its end flange can be made entirely of an electrically non-conductive plastic and is preferably a single piece.

[0018] The invention is explained in more detail below with reference to an exemplary embodiment in conjunction with the figures. These show: Fig. 1 the perspective view of the touch protection pin; Fig. 2 the three-dimensional representation of the contact carrier with mounted contact sleeve, socket contact, lamellar sleeve and touch protection pin; Fig. 3 the three-dimensional exploded view of the contact carrier; Fig. 4 the front view (left) and sectional side view (right) of the contact carrier with mounted contact sleeve, socket contact, lamellar sleeve and touch protection pin.

[0019] Figure 1 Figure 1 shows a perspective view of the touch protection pin 1 with an end tip 2 and a flange 4 located opposite the end tip 2. The actual pin body between the two end faces is formed by a shaft 3, which has a preferably round cross-sectional area and is cylindrical. The tip 2 can be rounded, as shown here.

[0020] The area between shaft 3 and flange 4 has a recess 5 that reduces notch effects, i.e., geometry-related stress peaks in the sense of internal material stresses due to external force. To optimally center and guide the touch protection pin 1 within the receiving bore of the contact carrier 10, the flange 4 can be supplemented with a shoulder 6.

[0021] Figure 2 The three-dimensional representation of the contact carrier 10 with mounted contact sleeve, socket contact, lamellar sleeve 11 and touch protection pin 1 is shown. The contact carrier 10 has a receiving bore into which the touch protection pin 1 and the contact sleeve 11 are pressed.

[0022] Figure 3 Figure 1 illustrates the three-dimensional exploded view of the contact carrier 10. The touch protection pin 1 and the socket contact 11 are pressed into the receiving bore in the sequence shown.

[0023] Figure 4shows the front view (left) and section side view (right) of the contact carrier 10 with mounted contact sleeve, socket contact, lamellar sleeve 11 and touch protection pin 1.

[0024] The touch protection pin 1 projects axially beyond the end of the contact carrier 10 by approximately one to two times its shaft diameter and is arranged in the blind hole direction of the receiving bore in front of the contact sleeve 11. This also applies, to a good approximation, to the lamellar sleeve 11.

[0025] In the axial direction of the blind hole, the touch protection pin 1 is fixed by crimping with its concentric contact shoulder formed by a shoulder 6 and the flange 4 on the side of the touch protection pin 1 and a concentric annular shoulder in the receiving bore formed by a bore diameter change between the contact sleeve 11 and the contact carrier 10. This means that the touch protection pin 1 is clamped in the receiving bore by the contact sleeve 11; the clamping forces result from the crimping of the contact sleeve 11 and the touch protection pin 1 in the blind hole. The clamping forces act in the axial direction between the concentric annular shoulder of the receiving bore and the concentric contact shoulder of the touch protection pin 1 and the axial concentric annular surface of the lamellar sleeve 11.

[0026] The geometric design of the pressed elements touch protection pin 1 and contact sleeve 11 ensures that the shaft 3 of the touch protection pin 1 is positioned both centrally and perpendicularly and thus aligned with the central axis of the contact carrier 10 and the socket contact 11.

[0027] The touch protection pin 1 is centered by the cylindrical outer surface of the shoulder 6 opposite the blind hole. A relief cut 12 in the receiving bore prevents the double centering that would otherwise occur if the flange 4 were to contact the blind hole with its outer cylindrical surface.

[0028] The paragraph 6 can have a recess 7 on the end face of the touch protection pin 1, so that on the one hand material is saved and on the other hand the ability of the paragraph 6 to deform elastically in the radial direction is increased.

[0029] The touch protection pin 1 has no provision for a tool for removal, for example an undercut or a corresponding contact surface, so that the touch protection pin 1 cannot be disassembled without damage, since the lamellar bushing 11 is firmly pressed into the receiving bore of the contact carrier 10.

[0030] The exemplary embodiment shown in Figure 2 , 3 and 4 is formed with a contact carrier 10. It is also possible to arrange touch protection pin 1 and socket contact 11 in a receiving bore of a plug contact housing, a connector housing or a housing cover of the plug connection. Reference symbol list

[0031] 1. Touch protection pin 2. Tip 3. Shank 4. Flange 5. Recess 6. Heel 7. Cutout 10 Contact carrier 11 Socket contact, lamellar sleeve, contact sleeve 12 Relief cut

Claims

1. Touch-protection pin (1) for a contact sleeve (11), comprising a shaft (3) and an end-side tip (2), wherein a flange (4) is arranged at the opposite end of the tip (2) of the touch-protection pin (1), so that the touch-protection pin (1) can be fixed in a receiving hole of a contact carrier (10) with a contact sleeve (11), characterized in that the region between the shaft (3) and the flange (4) has a recess (5) which is designed to reduce geometry-related stress peaks in terms of internal material loads due to an external action of force.

2. Touch-protection pin (1) according to Claim 1, characterized in that the flange (4) has a protrusion (6), so that the flange (4) has a concentric ring shoulder in the protrusion direction.

3. Touch-protection pin (1) according to Claim 2, characterized in that the protrusion (6) is cylindrical, so that centring of the touch-protection pin (1) within a receiving hole of a contact carrier (10) is assisted.

4. Touch-protection pin (1) according to Claim 2, characterized in that the protrusion (6) has a cutout (7) at the front side.

5. Touch-protection pin (1) according to Claim 1, characterized in that the touch-protection pin (1) is formed in one piece and from an electrically non-conductive plastic.

6. Contact carrier (10) for an electrically conductive, releasable plug-in connection, comprising a receiving hole for a socket contact (11), characterized in that a touch-protection pin (1) according to Claim 1 is inserted in the receiving hole centrally and perpendicularly with respect to the centre axis and is fixed by the socket contact (11).

7. Contact carrier (10) according to Claim 6, characterized in that the touch-protection pin (1) is fixed by axial clamping forces.

8. Contact carrier (10) according to Claim 6, characterized in that the receiving hole is a blind hole.

9. Contact carrier (10) according to Claim 6, characterized in that the receiving hole has a clearance (12).

10. Electrically conductive, releasable plug-in connection, comprising at least one contact carrier (10) according to Claim 6.