EP2800205B1 - Partially solid hollow pin - Google Patents

Description

Background of the invention

The invention relates to a plug pin for producing an electrical contact between a power cord of a plug cable and a socket contact, wherein the plug pin has a connection end for electrical connection to the Netzanschlusslitze and leading from the connection end to a plug-side contact end electrically conductive central region, wherein the connecting end as a hollow crimp end is formed, and wherein the connection end and at least a part of the socket-side contact end are formed hollow by deep drawing or in extrusion molding.

Such at least partially hollow connector pins are described for example in WO 2009/021491 A2 . DE 20 2007 018 665 U1 . DE 10 2007 039 324 A1 . DE 10 2007 038 219 B3 . DE 20 2008 014 774 U1 . DE 10 2007 062 500 A1 , as in DE 196 27 335 C1 , in EP 0 128 990 A1 , in GB 2 083 716 A or in DE 101 51 990 A1 ,

But the basic idea of such a hollow pencil is already over DE 89 12 290 U1 , out EP 1 182 739 A2 , out EP 1 071 176 A1 or off EP 0 677 901 A1 known.

An extruded hollow pin is already in DE 11 18 303 B , a extruded push pin made of solid material is in DE 102 03 171 A1 , a extruded hollow connector in DE 31 23 850 C2 or for example in US 2006/0102375 A1 , a connector bridge with extruded hollow plug pin in DE 20 2007 017 752 U1 and a pin with connection hole at the connection end in DE 86 33 492 U1 disclosed.

Connector bridges, such as those in DE 10 2009 049 369 B4 are used in particular in the UK and in English-speaking countries. The special feature of this plug is that the Erdleiterstift serves as a mechanical unlocking when plugging the device plug into the socket of the power or power supply network. This Erdleiterstift is longer than the phase and Nulleiterstifte, and only with the insertion of this Erdleiterstiftes, it is possible that the other two pins can be inserted functionally.

These and similar jumper bridges are installed in large quantities in the production of device connectors. Since relatively small price differences already have a significant impact on competitiveness in the fiercely contested market, developments to reduce costs or material in this technical field are particularly important.

Starting from standardized constructions, as in DE 198 01 896 C1 and DE 100 51 348 C2 have been tried, among other things, by the trimming and plastic fill the otherwise massive pins, Save material, such as in DE 10 2007 009 422 A1 shown. However, this method of material saving has a disadvantageous effect on the production speed and thus ultimately on the production costs because of the complex processing. While production figures of about 80 to 100 pieces per minute are achieved for the massive connector pins, only 60 to 80 pieces per minute are needed for the milled connector pins.

In DE 43 14 195 A1 a pin is described, which is formed from a rolled sheet metal strip. The interior of the connector pin can also be filled with plastic. In this way, only round pin shapes can be made.

In the DE 10 2009 049 369 B4 is described a connector bridge with folding pins, which receive their final outer shape during encapsulation. In particular, much material is saved here. However, due to the folding process, the insertion bevels of the plug pins on the narrow sides of the pins have gaps which are then filled with plastic during the encapsulation. Such plastic deposits may prove to be disadvantageous in extreme situations at high currents and high temperatures. In addition, no contacting is possible at these locations. Therefore, such pins are no longer approved in the UK. These issues are resolved by the in DE 10 2009 052 950 B4 or in DE 10 2011 103 104 B4 described connector bridges.

• So muss etwa beim Vercrimpen der Netzanschlusslitze des Steckerkabels im Verbindungsende akribisch darauf geachtet werden, dass die Vercrimpung auf jeden Fall kunststofffluiddicht ausgeführt wird, so dass ein flüssigkeitsdichter Pfropfen den Hohlkanal des Steckerstifts abschließt. Sonst ist nämlich beim Vergießen des Steckerstifts in die aus thermoplastischem Material aufgebaute Grundplatte der Steckerbrücke ein Eindringen des -zu diesem Zeitpunkt flüssigen- Kunststoffs in das Innere des Hohlstifts zu befürchten, was unbedingt vermieden werden muss. Leider ist dies bei einem niederpreisigen Massenartikel wie dem in Frage stehenden Steckerstift in einem industriellen Maßstab, zumindest ohne erhebliche zusätzliche und damit selbstverständlich kostentreibende Qualitätssicherungsmaßnahmen, nicht zu garantieren.

But also the initially discussed extruded hollow connector pins, such as in WO 2009/021491 A2 , in DE 20 2007 018 665 U1 , in DE 10 2007 039 324 A1 , in DE 10 2007 038 219 B3 , in DE 20 2008 014 774 U1 or in DE 10 2007 062 500 A1 Despite the achievable undoubtedly cost-saving material reduction compared to solid pencils, these still have some considerable disadvantages:

• For example, when crimping the power cord of the plug cable in the connecting end, care must be taken to ensure that the crimping is carried out in any case in a plastic fluid-tight manner so that a liquid-tight plug closes off the hollow channel of the plug pin. Otherwise, namely when pouring the pin into the built-up of thermoplastic material base plate of the connector bridge penetration of -zu-this time liquid plastic to be feared in the interior of the hollow pin, which must be avoided at all costs. Unfortunately, this is in a low-priced mass-produced items such as the relevant pin in an industrial scale, at least without significant additional and thus of course cost-driving quality assurance measures can not be guaranteed.

Another significant disadvantage of the connector pin according to this prior art is that it does not meet the required strength requirements, especially in the mechanically particularly heavily loaded central region due to the proposed hollow design of the central region and therefore relatively thin wall thickness.

Although in the above-discussed prior art, the - additional - training a torsion and / or Ausziehschutzes by providing a thickening on the outer circumference of the central region, where the pin is to sit in the plug-bridge body, excited. This thickening should then also be profiled by knurling, recessing and / or embossing and, of course, locally reinforces the hollow central area, since this thickening gives it a greater wall thickness. However, this is obviously again only by increased use of materials in the pin "bought", which is diametrically contrary to the declared goal of this state of the art. In addition, the additional manufacturing steps that become necessary as a result undoubtedly have an unfavorable effect on the production costs of the connector pin.

Task of invention

Object of the present invention is in contrast to improve a generic pin with the technical features described above by simple technical means inexpensive and inexpensive and without the use of additional parts to the extent that continue in the production of considerable material and thus in particular weight and cost can be saved, the plug pin but in its central region, where it is installed in the plastic base plate of a jumper is compared to the known, especially extruded hollow pins considerably mechanically reinforced and beyond the pouring of the connector pin in the base plate of the connector bridge the Danger of penetrating into the cavities of the connector pin liquid plastic or moisture due to the prevailing ambient atmosphere with absolute certainty is avoided.

Short description of invention

This - technically quite sophisticated - task is inventively solved in equally amazingly simple and surprisingly effective manner that the connecting end and at least a portion of the socket-side contact end hollow by forming, in particular by deep drawing or extrusion molding, the central area, however, by concentric pressing, rolling or Rejuvenating wall parts of the central region radially to the axis plastic fluid-tight and at least partially solid without continuous cavity between the connecting end and steckdosenseitigem contact end are formed.

• Anstelle eines hohl gestalteten Mittelbereichs verlangt die erfindungsgemäße Lehre einen durch konzentrisches Verpressen, Rollieren oder Verjüngen von Wandteilen des Mittelbereichs radial zur Achse zumindest teilweise massiven, kunststofffluiddicht gestalteten Mittelbereich des Steckerstifts, bei welchem im Gegensatz zu dem etwa in WO 2009/021491 A2 beschriebenen Steckerstift eben gerade kein durchgängiger Hohlraum zwischen Verbindungsende und steckdosenseitigem Kontaktende ausgebildet ist, sondern der Mittelbereich des erfindungsgemäßen Steckerstifts ist massiv ausgebildet, was gerade in diesem mechanisch besonders stark beanspruchten Bereich zu einer wesentlichen Erhöhung der Festigkeit führt. Lediglich das Verbindungsende und zumindest ein Teil des steckdosenseitigen Kontaktendes sind erfindungsgemäß durch Umformung - aus einem ursprünglich massiven metallenen Rohling - hohl gestaltet, wie weiter unten im Detail erläütert wird. Ob diese Umformung nun insbesondere durch Tiefziehen, durch Fließpressumformung oder durch eine sonstige geeignete Umformtechnik erfolgt, spielt dabei technisch übrigens keine entscheidende Rolle.

The present invention thus proposes the exact opposite of what the cited prior art according to the documents WO 2009/021491 A2 . DE 20 2007 018 665 U1 . DE 10 2007 039 324 A1 . DE 10 2007 038 219 B3 . DE 20 2008 014 774 U1 and DE 10 2007 062 500 A1 teaches:

• Instead of a hollow-shaped central region, the teaching of the invention requires by concentric pressing, rolling or tapering of wall portions of the central region radially to the axis at least partially solid, plastic fluid-tight designed center region of the connector pin, wherein in contrast to the approximately in WO 2009/021491 A2 described connector pin just just no continuous cavity between the connecting end and steckdosenseitigem contact end is formed, but the central region of the connector pin according to the invention is solid, which leads to a substantial increase in strength especially in this mechanically stressed region. Only the connection end and at least part of the plug-side contact end according to the invention by forming - made of an originally solid metal blank - hollow, as will be explained in detail below. Whether this transformation takes place in particular by deep drawing, by extrusion molding or by any other suitable forming technique, technically does not play a decisive role.

Nevertheless, it is possible due to the teachings of the invention, the substantial advantages of the local hollow pin listed in the above-mentioned prior art, namely a considerable saving in weight and material without major loss of strength to completely maintain the material strength at a particularly important and sensitive point the inventively prescribed massive version of the connector pin is even significantly increased in its central region.

In addition, the fact that no continuous cavity between the connection end and plug-side contact end is formed, ensures that when pouring the connector pin according to the invention in the plastic base plate of a connector bridge under no circumstances liquid plastic or Moisture over the connection end with the - of course hollow - crimping and the central area in the - again hollow - plug socket side contact end passes. In this context, it should be noted that under a "massive central area without continuous cavity" in the context of the invention, inter alia, a - about after a radial compression of a hollow blank - closed-fitting radially innermost material area can be understood. In this case, even tiny micro-gaps in a size range below 0.1 mm are permissible, without thereby forming a continuous hollow space between the connection end and the socket-side contact end, which in any case can be excluded.

Another practical advantage of the inventively designed connector pin is that by the - at least partially massive - training of the central region a defined stop when inserting the power cord is created in the hollow crimp end of the plug. Thus, a passage of the wire to the socket-side plug base - as is virtually unavoidable in the hollow pin according to the generic art discussed above - safely avoided. This, in turn, significantly increases process safety in manufacturing without any additional measures, which in turn dramatically increases the economic value of this mass-produced mass-produced article.

Finally, in the connector pin according to the invention also the not to be underestimated advantage that the "interior" of the socket-side hollow contact end of the teaching of the invention partially hollow post, which in practice will take the "lion's share" of the axial length of the pin, already before the manufacturing step of crimping is safely protected against oxidation as well as against corrosion by penetrating moisture.

When applying the teaching of the present invention in the central area solid pin therefore not only all the benefits of the extruded Hollow pin according to the above-mentioned prior art, as shown in the WO 2009/021491 A2 described, but its disadvantages discussed above can be avoided and beyond further significant benefits can be achieved.

Compared to the well-known "simple hollow pin" thus represents the invention "partial-solid hollow pin" something like a "quadrature of the circle" is.

Preferred embodiments of the invention

In embodiments of the connector pin according to the invention in commercially available sizes with particular market significance, the central region may have an axial length of 3mm to 8mm, preferably an axial length of about 5mm and solid on an axial length of 1mm to 3mm, preferably an axial length of about 2mm be formed without continuous cavity between the connecting end and steckdosenseitigem contact end.

Particularly preferred embodiments of the connector pin according to the invention are characterized in that the central region has an axial length of 10% to 20%, preferably an axial length of about 15% of the total axial length of the connector pin and an axial length of 5% to 10%, preferably formed on an axial length of about 7% of the total axial length of the connector pin solid without continuous cavity between the connecting end and steckdosenseitigem contact end. With these geometrical conditions, the above-mentioned main advantages of the plug pin according to the invention over the prior art, namely a significant weight and material savings at the same time significantly increased mechanical strength in the central region are most evident.

Also particularly advantageous is a class of embodiments in which the central region over the axial length of that section or those sections which are designed solid without a continuous cavity, at least one at its outer periphery Has cross-sectional constriction to 25% to 75%, preferably about 2/3 of the cross section of the remaining portions of the central region. A significant additional advantage of this embodiment of the connector pin according to the invention lies in the fact that its central region due to the "constriction around the waist" has a retention that acts in the sense of torsion and / or Ausziehschutzes and about a withdrawal of the pin after pouring into the Plastic base plate of a connector bridge from the still soft plastic opposes significant resistance, so that significantly increases the manufacturing security and the resulting rejects can be reduced to a minimum. Precisely because of the very high mechanical stress of the plug pin at this point, the particularly stable central area, which is massive in accordance with the invention, has an extremely positive effect here.

A group of embodiments of the connector pin according to the invention are characterized in that the central region is pressed in the radial direction transversely to the longitudinal axis of the connector pin. This has the advantage that the plug pin fixes even better in the axial direction in the plastic support body, which is very important for further processing in PVC overmolding and for process safety. Furthermore, the pin hole is closed to the cavity already at the connector bridge before crimping. Thus, no penetrating moisture is possible, which could be trapped by the crimping process, as is often the case in the prior art.

Another advantage due to the pin closure is a defined hole relationship or cavity depth and a defined cavity end on the lying for further processing during crimping of the individual strands of the core cross-section side.

Another group of embodiments is characterized in that the central region is helically wound around the longitudinal axis of the connector pin, whereby the natural material flow during extrusion is even better Account is taken. The mechanical strength is better pronounced. The pin hole to the cavity is closed.

Also advantageous is a group of embodiments in which the central region is conically pressed into the plug pin, wherein preferably the conically shaped central region tapers from the connecting end to the socket-side contact end. This ensures that the pin receives a further improved torsional and expressive power protection.

Because the hollow cone produced has its largest opening cross-section in the direction of the power cord of the plug cable to be inserted into the crimp end 2a, the insertion of the strand is facilitated by a guiding action.

Finally, in an alternative group of embodiments, the middle region is pressed into the plug pin in a crowned manner. This also allows the area to be closed to the pen.

Further embodiments of the connector pin according to the invention can provide that the central region has a plurality of radial cross-sectional constrictions in axial sequence along the longitudinal axis of the connector pin. In this way it is possible that in a good relation between force and result of the pin is closed at the bottom of the hole. This reduces tool wear during production.

Also preferred are embodiments of the connector pin according to the invention, in which the socket-side contact end has an axial length of 10mm to 50mm, preferably of about 20mm and a continuous cavity on an axial length of 5mm to 48mm, preferably on an axial length of about 18mm. With these geometric relations, most important applications of the connector pin according to the invention can be covered.

Likewise embodiments are advantageous, which are characterized in that the socket-side contact end has an axial length of 50% to 80%, preferably has an axial length of about 2/3 of the total axial length of the connector pin and a continuous cavity on an axial length of 35% to 75%, preferably on an axial length of about 60% of the axial total length of the connector pin.

In the context of the present invention, a plug bridge with at least one plug pin of the type described above according to the invention, which is characterized in that it comprises a base plate made of thermoplastic material, preferably flame retardant plastic material, in which at least one plug pin is cast, wherein the thickness the base plate substantially corresponds to the axial length of the central region of the at least one connector pin. In this way, the statutory standard specifications for plug bridges with regard to fire prevention can be met in the vast majority of countries worldwide.

Furthermore, embodiments of this connector bridge are preferred, which are characterized in that an electrical fuse is provided against excessive current flow, which is required by law in many countries.

Also advantageous is a method for producing a connector pin of the type described above with a connection end for electrical connection to a power cord and leading from the connection end to a plug-side contact end electrically conductive central region, which is characterized in that in a first manufacturing step (a) from a hollow blank is produced by forming, in particular by deep drawing or extrusion molding, that in a second production step (b) the initially hollow cross section in the central region of the hollow blank by concentric pressing, rolling or tapering radially to the axis of the hollow blank in such a way is compressed, that the central region of the compressed blank plastic fluid-tight and at least partially solid without continuous cavity between the connecting end and steckdosenseitigem Contact end is formed, and that then in a third manufacturing step (c), the hollow connection end of the compressed blank is formed by rolling, embossing or cutting as a crimp end, so that a plug pin for establishing an electrical contact between a power cord of a plug cable and a socket contact is formed.

In this way, according to the invention, modified plug pins can be inexpensively produced in the required, very high number of pieces and in economic cycle times.

Due to the subsequent mechanical deformation of the central region by the compression prescribed according to the invention, an additional strengthening of this region of the connector pin which is subjected to particularly high stress is surprisingly achieved, which was not to be foreseen from the outset. In particular, this also improves the metallic microstructure orientation of the material in its crystalline structure. Voids and deformation errors, as they are practically unavoidable in industrial production in large numbers, play no more relevant role in the connector pins produced according to the teaching of the invention.

Particularly preferred is a variant of this method, wherein at least at the beginning of the second manufacturing step (b) the forming tool used in the first production step (a) for producing the hollow blank from the solid metallic blank with a punch end portion still at the axial height of the connection end is seated in the cavity of the hollow blank, while the hollow blank is subjected to concentric pressing, rolling or tapering at the axial height of the later central region of the resulting compressed blank radially to the axis. The punch end of the forming tool used thus acts as a counter-bearing during compression of the central region, resulting in an additional - highly desirable - material hardening and a particularly well-defined geometric shape of the massive bottleneck (s) contributes.

Further advantages of the invention will become apparent from the description and the drawings. Likewise, the features mentioned above and those listed further can be used individually or in any combination. The embodiments shown and described are not to be understood as exhaustive enumeration, but rather have exemplary character for the description of the invention.

Drawing and detailed description of the invention

Fig. 1a

einen schematischen Längsschnitt durch eine erste Ausführungsform des erfindungsgemäßen Steckerstifts mit in radialer Richtung verpresstem Mittelbereich in einem in die Grundplatte einer Schutzbereich eingebauten Zustand;

Fig. 1b

eine Seitenansicht der Ausführungsform nach Fig. 1 a;

Fig. 2a

einen schematischen Längsschnitt durch eine zweite Ausführungsform mit um die Längsachse des Stifts verwundenem Mittelbereich;

Fig. 2b

eine Seitenansicht der Ausführungsform nach Fig. 2a;

Fig. 2c

einen schematischen Querschnitt in der horizontalen Schnittebene A-A gemäß Fig. 2b;

Fig. 3a

einen schematischen Längsschnitt durch eine dritte Ausführungsform mit konisch eingepresstem Mittelbereich;

Fig. 3b

eine Seitenansicht der Ausführungsform nach Fig. 3a;

Fig. 3c

einen schematischen Querschnitt in der horizontalen Schnittebene A-A gemäß Fig. 3b;

Fig. 4a

einen schematischen Längsschnitt durch eine zweite Ausführungsform mit ballig eingepresstem Mittelbereich;

Fig. 4b

eine Seitenansicht der Ausführungsform nach Fig. 4a;

Fig. 4c

einen schematischen Querschnitt in der horizontalen Schnittebene A-A gemäß Fig. 4b;

Fig. 5

eine Veranschaulichung der Verfahrensschritte (a) bis (c) anhand von schematischen Längsschnitten der Rohlinge beziehungsweise des Steckerstifts mit dem jeweiligen Verarbeitungswerkzeug in den einzelnen Herstellungsstadien.

Show it:

Fig. 1a

a schematic longitudinal section through a first embodiment of the connector pin according to the invention with compressed in the radial direction central region in a built-in the base plate of a protection area state;

Fig. 1b

a side view of the embodiment according to Fig. 1 a;

Fig. 2a

a schematic longitudinal section through a second embodiment with wound around the longitudinal axis of the pin central region;

Fig. 2b

a side view of the embodiment according to Fig. 2a ;

Fig. 2c

a schematic cross section in the horizontal sectional plane AA according to Fig. 2b ;

Fig. 3a

a schematic longitudinal section through a third embodiment with a conically pressed central region;

Fig. 3b

a side view of the embodiment according to Fig. 3a ;

Fig. 3c

a schematic cross section in the horizontal sectional plane AA according to Fig. 3b ;

Fig. 4a

a schematic longitudinal section through a second embodiment with crowned pressed central region;

Fig. 4b

a side view of the embodiment according to Fig. 4a ;

Fig. 4c

a schematic cross section in the horizontal sectional plane AA according to Fig. 4b ;

Fig. 5

an illustration of the method steps (a) to (c) based on schematic longitudinal sections of the blanks or the connector pin with the respective processing tool in the individual stages of manufacture.

In the various figures of the drawing, the same features are designated by the same reference numerals for clarity.

The FIGS. 1a to 4c show embodiments of a connector pin 1 according to the invention ; 1.1; 1.2; 1.3; 1.4 for making electrical contact between a power cord of a patch cord and a socket contact, wherein the pin 1; 1.1; 1.2; 1.3; 1.4 a longitudinal axis a, a connection end 2 for electrical connection to the power cord and a leading from the connection end 2 to a socket-side contact end 3 electrically conductive central region 4; 4.1; 4.2; 4.3; 4.4 , and wherein the connection end 2 is formed as a crimp end 2a . The plug pin 1 according to the invention; 1.1; 1.2; 1.3; 1.4 is characterized in that the connecting end 2 and at least a part of the socket-side contact end 3 hollow by deep drawing or in extrusion molding, the central region 4; 4.1; 4.2; 4.3; 4.4, however, plastic fluid-tight and at least partially massive are formed without continuous cavity between the connecting end 2 and plug-side contact end 3.

Fig. 1a FIG. 3 illustrates an embodiment of the plug pin 1.1 according to the invention in a schematic longitudinal section containing the longitudinal axis. The middle section 4.1 is compressed in all directions in a direction radial to the longitudinal axis a from all sides to a solid, plastic fluid-tight barrier between the connection end 2 and the socket side Training contact 3. Fig. 1 b shows the pin 1.1 Fig. 1 a in a side view. Indicated in both figures, respectively, the installation situation of the connector pin 1.1 in the base plate 5 a - for clarity in the drawing otherwise not shown - connector bridge.

In Fig. 2a is again shown in longitudinal section the structure of a further embodiment of the connector pin 1.2 according to the invention, which has a wound around the longitudinal axis of the connector pin around 1.2 center area 4.2, as in the side view of Fig. 2b is clearly visible. Fig. 2c shows in horizontal section through the plane AA of Fig. 2b the cross-section of the central area 4.2 at its narrowest point.

Fig. 3a also shows a schematic longitudinal section of an embodiment of the plug pin 1.3 according to the invention with a central region 4.3, which is conically pressed into the plug pin 1.3. In the illustrated embodiment, the conically shaped central region 4.3 tapers from the connection end 2 to the socket-side contact end 3 in order to facilitate the insertion of the power cord of a plug cable - both of which are not shown in the drawing. The side view of the pin 1.3 in Fig. 3b as well as in Fig. 3c shown cross section of the central region 4.3 Fig. 3b illustrate the fluid-tight barrier produced by the conical shape of the central region 4.3 between the connection end 2 and the socket-side contact end 3 of the connector pin 1.3.

Fig. 4a shows a longitudinal section of an embodiment of the connector pin 1.4 according to the invention, in which the central region 4.4 is pressed into the connector pin 1.4 spherically. Fig. 4b provides the to the embodiment of Fig. 4a associated side view and Fig. 4c again the cross-section of the central area 4.4 Fig. 4b ,

Technically feasible and quite advantageous for specific applications are further embodiments of the inventive plug pin (not shown in the drawing) in which the central region has a plurality of radial cross-sectional constrictions in axial sequence along the longitudinal axis of the plug pin.

• In einem ersten Herstellungsschritt (a) wird aus einem massiven metallischen Rohling 1' durch Umformung, insbesondere durch Tiefziehen oder durch Fließpressumformung ein hohler Rohling 1" erzeugt.

Fig. 5 finally illustrates - in the time sequence from left to right - the various stages of the manufacturing process of a connector pin according to the invention 1:

• In a first production step (a) , a hollow blank 1 "is produced from a solid metallic blank 1 ' by deformation, in particular by deep-drawing or by extrusion molding.

In a second production step (b) , the initially hollow cross-section in the central region 4 of the hollow blank 1 "is compressed by concentric pressing, rolling or tapering radially to the longitudinal axis of the hollow blank 1" such that the central region 4 of the compressed blank 1 "'plastic fluid-tight and is at least partially solid without continuous cavity between the connection end 2 and steckdosenseitigem contact end 3 is formed.

Subsequently, in a third production step (c), the hollow connecting end 2 of the compressed blank 1 "is formed by crimping, embossing, cutting or similar known processing methods as a crimp end 2a, so that finally a plug pin 1 according to the invention for establishing an electrical contact between a power cord of a Plug cable and a socket contact arises.

At least at the beginning of the second production step (b), the forming tool used in the first production step (a) for producing the hollow blank 1 "from the solid metallic blank 1 'still has a punch end section at the axial height of the connecting end 2 in the cavity the hollow blank 1 ", while the hollow blank 1" is subjected to a concentric pressing, rolling or tapering at the axial height of the later central region 4 of the resulting compressed blank 1 '"radially to the axis. As a result, the stamp end of the tool can then act as an abutment in the radial deformation and solidification of the central region 4 taking place in the third production step (c).

LIST OF REFERENCE NUMBERS

1

pin

1.1

Connector pin with radially compressed central area

1.2

Pin with twisted middle section

1.3

Connector pin with conically pressed middle section

1.4

Connector pin with convex pressed central area

1'

massive metallic blank

1"

hollow blank

1'"

in the middle area compressed blank

2

connecting end

2a

crimping

3

Contact end

4

the central region

4.1

in the radial direction compressed central region

4.2

around the longitudinal axis of the pin twisted middle area

4.3

conically pressed center area

4.4

crowned central area

5

Plug bridge base plate

a

Longitudinal axis of the connector pin

Claims (15)

1. Plug pin (1; 1.1; 1.2; 1.3; 1.4) for producing an electrical contact between a mains connection strand of a plug cable and a socket contact, the plug pin (1; 1.1; 1.2; 1.3; 1.4) comprising a longitudinal axis (a), a connecting end (2) for electrical connection to the mains connection strand and an electrically conducting central area (4; 4.1; 4.2; 4.3; 4.4) that extends from the connecting end (2) to a contact end (3) on the side of the socket, wherein the connecting end (2) is formed as a hollow crimp end (2a) and wherein the connecting end (2) and at least part of the contact end (3) on the side of the socket are formed to be hollow through deep drawing or extrusion shaping,
   characterized in that
   the central area (4; 4.1; 4.2; 4.3; 4.4) is formed by concentric compression, rolling or tapering of wall parts of the central area (4; 4.1; 4.2; 4.3; 4.4) in a radial direction with respect to the axis to be plastic fluid-tight, and is formed at least in sections to be solid without continuous cavity between the connecting end (2) and the contact end (3) on the socket side.
2. Plug pin according to claim 1, characterized in that the central area (4; 4.1; 4.2; 4.3; 4.4) has an axial length of 3mm to 8mm, preferably an axial length of approximately 5mm and is formed to be solid without continuous cavity between the connecting end (2) and the contact end (3) on the socket side along an axial length of 1mm to 3mm, preferably along an axial length of approximately 2mm.
3. Plug pin according to claim 1 or 2, characterized in that the central area (4; 4.1; 4.2; 4.3; 4.4) has an axial length of 10% to 20%, preferably an axial length of approximately 15%, of the overall axial length of the plug pin (1; 1.1; 1.2; 1.3; 1.4) and is formed to be solid without continuous cavity between the connecting end (2) and the contact end (3) on the socket side along an axial length of 5% to 10%, preferably along an axial length of approximately 7% of the overall axial length of the plug pin (1; 1.1; 1.2; 1.3; 1.4).
4. Plug pin according to any one of the preceding claims, characterized in that along the axial length of that section or those sections which are formed to be solid without continuous cavity, the outer circumference of the central area (4; 4.1; 4.2; 4.3; 4.4) has at least one cross-sectional narrowing to at least 25% to 75%, preferably to approximately 2/3, of the cross-section of the other sections of the central area (4; 4.1; 4.2; 4.3; 4.4).
5. Plug pin according to any one of the claims 1 through 4,
   characterized in that the central area (4.1) is compressed in a radial direction transversely to the longitudinal axis (a) of the plug pin (1.1).
6. Plug pin according to any one of the claims 1 through 4,
   characterized in that the central area (4.2) is helically wound around the longitudinal axis (a) of the plug pin (1.2).
7. Plug pin according to any one of the claims 1 through 4,
   characterized in that the central area (4.3) is conically pressed into the plug pin (1.3), wherein the conically shaped central area (4.3) preferably tapers from the connecting end (2) towards the contact end (3) on the socket side.
8. Plug pin according to any one of the claims 1 through 4,
   characterized in that the central area (4.4) is spherically pressed into the plug pin (1.4).
9. Plug pin according to any one of the preceding claims, characterized in that the central area has a plurality of radial cross-sectional narrowings in axial sequence along the longitudinal axis of the plug pin.
10. Plug pin according to any one of the preceding claims,
    characterized in that the contact end (3) on the socket side has an axial length of 10mm to 50mm, preferably of approximately 20mm and a continuous cavity along an axial length of 5mm to 48mm, preferably along an axial length of approximately 18mm.
11. Plug pin according to any one of the preceding claims,
    characterized in that the contact end (3) on the socket side has an axial length of 50% to 80%, preferably an axial length of approximately 2/3, of the overall axial length of the plug pin (1; 1.1; 1.2; 1.3; 1.4) and a continuous cavity along an axial length of 35% to 75%, preferably along an axial length of approximately 60%, of the overall axial length of the plug pin (1; 1.1; 1.2; 1.3; 1.4).
12. Plug bridge comprising at least one plug pin (1; 1.1; 1.2; 1.3; 1.4) according to any one of the preceding claims, characterized in that the plug bridge comprises a base plate (5) of thermoplastic material, preferably hardly inflammable plastic material, into which at least one plug pin (1; 1.1; 1.2; 1.3; 1.4) is cast, wherein the thickness of the base plate (5) substantially corresponds to the axial length of the central area (4; 4.1; 4.2; 4.3; 4.4) of the at least one plug pin (1; 1.1; 1.2; 1.3; 1.4).
13. Plug bridge according to claim 12, characterized in that an electrical fuse is provided as protection against an excessive current flow.
14. Method for producing a plug pin (1; 1.1; 1.2; 1.3; 1.4) according to any one of the claims 1 through 11 comprising a connecting end (2) for electrical connection to a mains connection strand and an electrically conducing central area (4; 4.1; 4.2; 4.3; 4.4) which extends from the connecting end (2) to a contact end (3) on the socket side, characterized in that in a first production step (a) a hollow blank (1") is produced from a solid metallic blank (1') through shaping, such as deep drawing or extrusion shaping,
    that in a second production step (b) the initially hollow cross-section in the central area (4; 4.1; 4.2; 4.3; 4.4) of the hollow blank (1") is compressed by concentric compression, rolling or tapering radially with respect to the axis of the hollow blank (1") in such a manner that the central area (4; 4.1; 4.2; 4.3; 4.4) of the compressed blank (1"') is formed to be plastic fluid-tight and at least in sections solid without continuous cavity between connecting end (2) and contact end (3) on the socket side,
    and that subsequently in a third production step (c) the hollow connecting end (2) of the compressed blank (1"') is formed as a crimp end (2a) by rolling, embossing or cutting such that a plug pin (1) is produced for producing an electrical contact between a mains connection strand of a plug cable and a plug contact.
15. Method according to claim 14, characterized in that at least at the beginning of the second production step (b), a punch end section of the forming tool used in the first production step (a) for producing the hollow blank (1") from the solid metallic blank (1') is still seated at the axial height of the connecting end (2) in the cavity of the hollow blank (1"), whereas the hollow blank (1") is subjected to concentric compression, rolling or tapering in a radial direction with respect to the axis at the axial height of the future central area (4; 4.1; 4.2; 4.3; 4.4) of the compressed blank (1"') to be produced.

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