The invention relates to plug contact modules and a plug contact arrangement as used in particular in industrial input/output modules.

Industrial input/output modules are described, for example, in DE4402002 Al, EPl 173902 Bl and US 2001/034165 Al. The industrial input/output modules are generally mounted on a carrier rail. A plurality of modules can be combined by means of their lateral faces. The insertion movement in this instance is carried out owing to guiding and retention devices at the lateral faces in a direction parallel with the lateral face towards the carrier rail. Contacts are arranged in the lateral faces so as to be accessible from the outer side and serve to supply electrical power and to transmit data and, when pushed together, become automatically connected to the contacts of the adjacent module. Owing to the often rough handling of these modules, the plug connections must be robust and also allow reliable contacting under adverse environmental conditions.

There is shown in Figure 7 in EPl 173902 Bl a plug contact module which has two contact members which together delimit a contact blade receiving member. The contact blade receiving member is arranged in a lateral wall of the input/output module so as to be accessible from the outer side. At the other opposing lateral wall, additional plug contact modules with contact blades are arranged so as to be accessible from the outer side. When connecting two input/output modules along their lateral faces, in the direction towards the carrier rail, the contact blades automatically move into the contact blade receiving member and produce an electrical connection to the contact members of the other plug contact module. In this manner, a data flow can take place between adjacent input/output modules and via a plurality of input/output modules which are connected to each other.

Practice has shown that the plug contact modules described in EPl 173902 Bl in the form of socket and blade contacts do not meet the requirements for a loss-free transmission with the currently required high data rates in the range of several gigabits per second - this corresponds to a loss-free transmission of signal frequencies in the gigahertz range. An object of the invention is consequently to improve the plug modules and plug contact arrangements known from the prior art, in particular EP1173902 Bl, using simple and cost-effective structural measures in such a manner that frequencies in the gigahertz range can be transmitted without any losses in terms of robustness. The plug modules and plug contact arrangements which have been improved in this regard should further be able to be used without modifications in place of the old plug modules and plug contact modules.

This object is achieved according to the invention by a plug contact module for transmitting frequencies in the gigahertz range along a signal path, having a contact portion which is constructed as a socket contact and which has at least two contact members which are connected to each other on a member base and which delimit a contact blade receiving member which is open at least in an insertion direction at two opposing sides and which are provided in the region of the contact module receiving member with contact faces for contacting a complementary plug contact module, the contact members extending in a linear manner and parallel with each other from the member base in the direction towards the contact module receiving member when the contact faces have a spacing from each other which corresponds to the sum of the material thicknesses of the contact members. Relatively small deviations from the parallel nature in the range of ±2° and such deviations in the linearity may still be tolerable in particular at frequencies in the lower gigahertz range.

The above object is further achieved by a plug contact module for transmitting frequencies in the gigahertz range along a signal path having a contact portion which is constructed as a contact blade which is constructed so as to be able to be introduced into a contact blade receiving member of a socket contact and which is produced from at least two layers of a metal sheet.

Finally, the object according to the invention is solved by a plug contact arrangement for transmitting frequencies in the gigahertz range between a first plug contact module, which has a contact blade receiving member which is open at least in an insertion direction and which is delimited at opposing sides by contact members, and a second plug contact module which has a contact blade which is constructed so as to be able to be introduced into the contact blade receiving member and to be able to be brought into electrical contact with the contact member, and whose material thickness corresponds to the sum of the material thicknesses of the contact members.

Owing to this configuration of the plug contact modules and the plug contact arrangement, the transmission of signals having frequencies in the gigahertz range between the plug contact modules is improved. The transmission losses are reduced. In the case of the plug contact module having the contact portion which is constructed as a socket contact, transmission of high frequencies in the gigahertz range with a lower level of losses is achieved in that, when a contact blade is used whose material thickness corresponds to the sum of the material thicknesses of the contact members, the contact members extend parallel with each other. Two advantageous effects are thereby achieved: on the one hand, with a contact blade whose material thickness corresponds to the material thickness of the contact members, owing to the homogeneous path of the material thickness, a

homogeneous impedance path is achieved in the direction of the signal path via the contact portions. On the other hand, the contact members in such a contact blade extend parallel with each other so that the signal path is guided by the contact blade and the contact members in a linear and parallel manner. The configuration of the contact springs is thus based heavily on the shape of a waveguide which is ideal for the further direction of high frequencies. In the plug contact module with the contact portion which is constructed as a contact blade, the production from two layers of a metal sheet leads to the material thickness of the contact blade being adapted in a simple manner to the overall material thickness of two contact members of a socket contact, for example, by the same sheet metal material being used for the socket contact having the two contact members and the contact blade.

Consequently, the configuration of the contact blade according to the invention ensures in a simple manner that the material thicknesses of the contact blades and the socket contact used to transmit the signal frequencies are the same, which leads to a more homogeneous signal path. The construction of the contact blade from at least, preferably precisely, two layers which are preferably joined together over the full surface and/or at their flat sides reflects the structure of the socket contact comprising at least, preferably precisely, two contact members. This symmetry in terms of structure reduces transmission losses in spite of simple production. In comparison with the construction according to the invention, the known contact members of the plug contact modules of EP1173902 Bl on the member base are too far away from each other, as can be seen in particular from Figure 6 of EP1173902 Bl. The contact blades are further not produced from two layers of a metal sheet. Consequently, in the transition between a contact blade and contact member, there is an increase in the material thickness which leads to signal reflections in the gigahertz range. Furthermore, the contact members, owing to the relatively large spacing on the member base, extend towards each other in the direction towards the contact blade when the contact blade is inserted, which also reduces the transmission quality in the gigahertz range.

The solution according to the invention can be further improved by the features which are described below, are advantageous per se and can be combined with each other as desired.

According to a first advantageous embodiment, the contact members each continue, when viewed from the contact blade receiving member, in a linear manner along the member base as far as a conductor path contact portion. This construction leads to low impedance and good transmission of signal frequencies in the gigahertz range along the contact members and also on the other side of the contact members. Signal reflections owing to directional changes of the signal path cannot occur with this configuration. The

construction of the plug contact module, which is based on that of a waveguide, is also continued in this region. On the printed circuit board contact portion, the plug contact module can be connected to a printed circuit board or, in particular if it is desirable to directly loop the signal path through the plug contact modules, to another plug contact module.

The contact members may further extend, when viewed from the contact blade receiving member, at the other side of the member base in a linear manner as far as a stop for a printed circuit board contact spring at an end of the plug contact module opposite the contact blade receiving member. In place of a stop, a contact face may also be arranged at this location. It is further advantageous for preventing signal reflections when, according to a further improvement, the contact members continue along the signal path with constant material thickness at the other side of the member base. This can be achieved in a simple manner, for example, by the plug contact module being produced from a preferably single-piece metal sheet with constant material thickness, in particular folded and/or tacked.

The contact members may be constructed so as to be resilient transversely relative to the insertion direction so that they are redirected when a contact blade is inserted into the contact receiving member and press against the contact blade. In the non-redirected rest state, the contact members may taper towards each other from the member base towards the contact blade receiving member so that, when a contact blade is inserted, the contact members extend in a parallel manner and apply a contact force to the contact blade.

The contact faces may be constructed in a curved manner in order to enable at least one line contact which is preferably parallel with the insertion direction. Owing to the curvature, the surface pressure increases and consequently the contact reliability.

In the region of the member base, the contact members can be connected to each other by means of a curved reinforcement member. The member base is thus reinforced with respect to the contact members. A redirection of the contact members consequently does not lead to an expansion of the member base. The curved reinforcement member, when viewed from the contact receiving member, may continue at the other side of the member base, in particular as far as the printed circuit board contact portion.

The contact members, when viewed from the contact blade receiving member, may further continue preferably in a linear manner at the other side of the member base in an extension portion which is more rigid compared with the contact springs and in which they are connected to each other by means of a curved reinforcement member. The curved reinforcement member may extend continuously over the extension portion so that it has a high level of mechanical stability, even with a great length. The cross-section surface-area perpendicular relative to the signal path may be U-shaped in the extension portion. Owing to the linear and parallel path of the contact members when the contact blade is inserted and its continuation in the extension portion as, for example, the linear and parallel lateral walls thereof, the shape of the plug contact module approaches the ideal shape of a waveguide which transmits signals in the gigahertz range with a low level of loss. The contact faces may each be arranged on or close to the free end of the contact members opposite the member base.

The contact members may each be provided, preferably at the free ends thereof, with a contact plate which protrudes in the insertion direction at least at one side with respect to the respective contact member and is provided in the insertion direction with an inclined introduction portion. Such a contact plate facilitates the insertion of the contact blade into the contact blade receiving member. The contact plates preferably have the same material thickness as the contact members and are in alignment with the outer faces or flat sides thereof in order to avoid impedance increases.

The two metal sheet layers of the contact blade can be joined together by means of folding or tacking, as can the entire plug contact module, so that no additional operating steps are necessary in order to produce the contact blade. At least in the insertion direction, the edges of the contact blade may be chamfered in order to facilitate insertion into the contact blade receiving member. The chamfering is preferably embossed and preferably extends over at least half of the material thickness of a metal sheet layer.

In order to enable a signal flow which is not disrupted to the greatest possible extent, the layers of the contact blade preferably extend along the signal path continuously as far as a printed circuit board contact portion at an end of the contact module opposite the contact blade. In order to improve the homogeneity of the signal path, the material thickness of the metal sheet layers should be constant along the signal path.

According to another advantageous embodiment, the layers of the contact blade which abut each other preferably in a planar manner, particularly over the entire surface, may continue along the signal path in particular as mutually spaced-apart lateral walls of an extension portion in which the lateral walls are connected to each other by means of at least one curved reinforcement member. The curved reinforcement member in the extension portion increases the mechanical stability of the contact blade.

The contact blade may preferably form planar contact faces at the flat sides thereof. The layers of the contact blade preferably extend parallel with the contact faces.

In particular, the layers may be spaced further apart from each other in the extension portion than in the contact blade. This leads to a relatively high torsional rigidity of the plug contact module. According to another advantageous embodiment, the layers of the contact blade, in particular at the end thereof located in the direction of the signal path, may be expanded so as to form shoulders which protrude substantially transversely relative to the contact faces. Such shoulders may improve the transmission quality at high frequencies since, with contact members which are located on the contact faces of the contact blades, a more uniform path of the outer faces of the connected plug contact modules becomes possible. The shoulders may additionally be closed with respect to the free end of the contact members and thus reduce reflections at these ends.

Regardless of whether the plug contact module is provided with a contact blade or with a socket contact, it is advantageous for a printed circuit board contact portion to be provided for contacting a printed circuit board or another electrical and/or electronic component at the end of the signal path opposite the contact portion. This arrangement of the printed circuit board contact portion leads to a linear signal path between a contact portion and printed circuit board contact portion and not to a signal path which is bent through 90°, as is the case, for example, in the plug contact module of EP1173902 Bl with the soldering lugs which protrude perpendicularly from the contact members and the contact blade.

The printed circuit board contact spring may be articulated to the curved reinforcement member of the extension portion in a development. The extension portion according to another advantageous embodiment is at least as long in the direction of the signal path as the contact portion or the contact blade and/or the contact members.

The lateral walls of the extension portion may form a stop for a resiliently redirectable printed circuit board contact spring so that, when the printed circuit board contact spring is completely redirected, the stop is provided as an additional conductor cross-section. Owing to the arrangement of the extension portion at the end of the plug contact module, the signal path extends in a linear manner along the lateral walls of the extension portion via the stop to the printed circuit board contact spring.

In order to allow an overtravel of the conductor contact spring and consequently tolerance compensation, it is advantageous for the stop to co-operate with a region of a first half of the printed circuit board conductor spring which begins at the articulation location.

Consequently, the free end of the printed circuit board contact spring is then still able to be redirected even when the first half is already in abutment with the stop. To this end, the printed circuit board contact spring, at the half facing the free end thereof, may be provided with a curvature which is directed away from the contact portion and which allows a redirection, even when the first half is already in abutment against the stop. The printed circuit board contact spring may further be bent back at the free end thereof in the direction of the contact portion. The extension portion may have a recess for receiving the free end of the printed circuit board contact spring.

According to an advantageous embodiment of the plug contact arrangement, when a contact blade is received in the contact blade receiving member, the outer faces of the contact members may be in alignment with the outer faces of an extension portion of the second plug contact module that is widened with respect to the contact blade.

Consequently, the outer faces of the plug contact arrangement continue over the connection location between the socket contact and contact blade substantially

continuously. Such a homogeneous lateral and substantially continuous outer skin leads to lower losses at high frequencies. A gap in the aligned outer skin of the plug contact arrangement between the free end of the contact member and the shoulders or the expanded extension portion should preferably be no more than one-tenth, preferably no more than one-twentieth, of the wavelength of the highest frequency which is present in the signal and is intended to be transmitted. For frequencies in the gigahertz range, the gap should, for example, be no more than 1 mm.

In order to produce a homogeneous signal path, the height of the contact members, measured transversely relative to the material thickness, may correspond to the height of the contact blade. The contact surface on which the contact blade and contact member are in mutual abutment extends in this configuration preferably over the entire height of the contact members. A homogeneous signal path is thereby also produced with respect to the height.

A homogeneous signal path is further achieved by the content of the cross-section surface- area of the contact blade corresponding to the sum of the contents of the cross-section surface-areas of the contact members, measured in each case transversely relative to the signal path. Deviations from this sizing rule should preferably be below 10% of the cross- section surface-area since otherwise signal reflections may occur owing to a surface crack.

If the plug contact modules of the plug contact arrangement have extension portions in one of the above-described configurations, the extension portions should preferably have, with respect to shape and/or surface content, the same cross-sections transversely relative to the signal path.

The extension portions of the plug contact modules of a plug contact arrangement may have different lengths so that plug contact arrangements can be adapted to different plug geometries.

A construction kit for the production of a plug connection for transmitting frequencies in the gigahertz contact comprises at least two plug contact modules in one of the above - described configurations, the plug contact modules having extension portions of different lengths for adaptation to various plug sizes. The plug contact modules are preferably constructed so as to be able to be introduced laterally, that is to say, transversely relative to the signal path.

The invention is explained in greater detail below by way of example with reference to the appended drawings. The combination of features described and illustrated below can be changed in accordance with the above configurations; the advantage connected with the respective feature should also not be the decisive aspect in individual applications.

In the drawings:

Figure 1 is a schematic, perspective view of an embodiment of industrial input/output modules, in which the invention can be used;

Figure 2 is a schematic, perspective view of two connected plug type connectors as used in the industrial input/output modules of Figure 1 ;

Figure 3 is a schematic, perspective view of components of one of the plug type connectors of Figure 2 having additional shielding plates;

Figure 4 is a schematic sectioned illustration through the plug type connector of Figure 1 with a printed circuit board inserted;

Figure 5 is a view of the plug contact arrangements, as contained in the connected plug type connectors of Figure 2;

Figure 6 is a first schematic perspective view of a plug contact module having a blade contact;

Figure 7 is another schematic perspective view of the plug contact module of Figure 6; Figure 8 is a schematic perspective view of a plug contact module having a socket contact; Figure 9 is another schematic perspective view of the plug contact module of Figure 8; Figure 10 is a schematic plan view of a plug contact arrangement having the plug contact modules of Figures 6 to 9;

Figure 11 is another embodiment of plug contact modules.

Figure 1 is a schematic perspective view of industrial input/output modules 1. The input/output modules may be fitted beside each other to a carrier rail 2. Depending on the function, they are provided, at their front sides 4 which face away from the carrier rail 2 and which are generally accessible for operating staff, with line connections and/or operating elements. The input/output modules 1 can be arranged directly beside each other on the carrier rail 2 so that their flat sides 6 are directly in abutment. So that they can be mutually replaced, the depths 7 thereof are generally standardised with modular dimensions in the longitudinal direction of the carrier rail 2. For securing the input/output modules, there may be provided positive-locking elements 8, such as, for example, undercut grooves which extend from the front side 4 to a rear side 10 which faces towards the carrier rail 2. Positive-locking elements 12 which are constructed accordingly in a complementary manner in the form of, for example, undercut ribs of the other flat side 6 in each case, move into the positive- locking elements 8 and guide the input/output modules 1 in a displacement direction 14, in this instance perpendicularly relative to the front side 4.

In the flat sides 6 there are integrated plug type connectors 16 which, when the

input/output modules 1 are pushed together in the displacement direction 14, automatically produce a contact with respect to a correspondingly complementary plug type connector 16 on the opposite flat side of the adjacent input/output module 1. Generally, each

input/output module 1 is provided at each of the two flat sides 6 thereof with a

complementary plug type connector 16 so that, in the case of adjacent input/output modules, mutually fitting plug type connectors always automatically face each other. Via the plug type connectors 16, there is also a data exchange between the input/output modules 1 via a plurality of interposed input/output modules 1.

An insertion direction 18, in which the plug type connectors 16 are connected to each other, corresponds to the displacement direction 14, in which the input/output modules are connected. The insertion direction 18 extends perpendicularly relative to a signal path (not illustrated in Figure 1) which extends from contact portions 20 of the plug type connectors 16 that are accessible from the outer side in a substantially perpendicular manner relative to the flat side 6 into the inner side of the input/output module 1 and from there to the plug type connector 16 at the other flat side 6. So that the contact portions 20 of opposing flat sides can be brought into contact with each other, at least one flat side is provided with groove-like recesses 22 which extend in a displacement or insertion direction 14, 18 to a contact portion 20 continuously over the entire flat side 6. When two input/output modules are connected, the contact portions (not shown in Figure 1) of one plug type connector are inserted into the groove-like recesses 22 and move therein in a displacement or insertion direction 14, 18 until they come into contact with the contact portions of the complementary plug type connector 16. In Figure 1, two input/output modules 1 which have already been connected in the displacement direction 14 on the carrier rail 2 are shown at the left-hand side. The input/output module 1 on the right-hand side in Figure 1 is illustrated in a state removed from the central input/output module in the displacement direction 14. Figure 2 schematically illustrates two plug type connectors 16 in the connected state, as produced, for example, with the connected input/output modules 1 shown on the left-hand side in Figure 1. The input/output modules 1 with their components are omitted in order to open up the view of the plug type connectors. The depth 24 of the plug type connectors 16 may correspond to the depth 7 of the input/output modules 1 so that the mutually complementary plug faces 26, 28 of the plug type connectors 16 come to rest in each case on a flat side 6 of an input/output module at the outer side. The plug type connectors 16 are provided with a plurality of adjacent shaft-like module receiving members 30 which each extend transversely relative to the plug faces 26, 28 in the depth direction 32 and open towards the plug faces 26, 28 so that the contact portions 20 are accessible from the outer side.

In Figure 2 it can be seen that, on one plug face 28, the contact portions 20 are constructed in the form of contact blades 34, which protrude with respect to a lateral face 36 of the plug face. When a plurality of input/output modules 1 are connected, the contact blades 34 are introduced into the recesses 22 (cf. Figure 1). Transversely over a plurality of module receiving members 30, the plug type connector 16 as shown in Figure 2 may also provide a similarly shaft- like receiving member 38 for a printed circuit board.

The plug type connectors 16 are, as described below, particularly constructed to transmit data with high data rates in the range of several gigabits per second corresponding to signal frequencies in the gigahertz range. Figure 3 is an exploded, schematic illustration of a plug type connector 16.

The plug type connector 16 has a, for example, parallelepipedal base member 40 of an electrically insulating material, such as a plastics material which is capable of being injection-moulded. The module receiving members 30 and the printed circuit board receiving member 38 may be formed in the base member 40.

In the module receiving members 30, there are received plug contact modules 42, 44 which form the mutually complementary contact portions 20 on the opposite plug faces 26, 28, respectively. The contact portion 20 of one plug contact module 42 is constructed as a socket contact 46. The contact portion 20 of the other complementary plug contact module 44 has, as a contact portion, a contact blade 34 which is constructed to be introduced in the insertion direction 18 into the socket contact 46.

The plug contact modules 42, 44 are preferably produced from a curved metal sheet which is punched into an appropriate shape, preferably by means of folding or tacking.

A signal path 48 extends substantially from the contact portion 20 of one plug contact module 42 to the contact portion 20 of the other complementary plug contact module 44 of the same plug connector 16. If a printed circuit board is arranged in the printed circuit board receiving member 38, the signals may be guided in the region between the plug contact modules 42, 44 via the printed circuit board. The insertion direction 18, in which the plug contact modules 42, 44 of input/output modules 1 which are to be joined together are intended to be connected extends perpendicularly relative to the signal path 48. A printed circuit board 38 may be arranged in the signal path 48.

In order to contact a printed circuit board (not illustrated in Figure 3) which is inserted into the printed circuit board receiving member 38, the plug contact modules 42, 44 are provided, at the end opposite the contact portion 20 of each plug contact module 42, 44 with respect to the signal path 48 with a printed circuit board contact portion 50, respectively. For securing in the module receiving members 30, the plug contact modules 42, 44 may be provided with securing elements 54 in the form of preferably punched or otherwise shaped positive-locking or fractionally engaging elements, such as, for example, catch projections or clamping springs.

For shielding, the plug type connector 16 may be provided with a shield 56, for example, in the form of two shielding plates 58 which together form a frame and which can be positioned around the lateral faces 57 of the plug type connector 16 that adjoin the plug faces 26, 28. At least one shielding plate may be provided with a slot-like recess 60 at the location corresponding to the printed circuit board receiving member 38 of the base member 40 so that printed circuit boards can be inserted through the shield 56 into the plug type connector 16. The shield may further be provided with recesses 61 which are open towards the edge at least at the side of the socket contacts 46 so that, when a plurality of plug type connectors 16 are connected in the insertion direction 18, the contact blades 34 can pass the shield 56. When the plug type connectors 16 are assembled, the recesses 61 are in alignment with the recesses 22 of the input/output modules 1 (cf. Figure 1). At the narrow sides 62 of the plug type connector 16, there may be provided in addition to the plug faces 26, 28 retention webs 64 which extend parallel with the plug faces 26, 28 and between which narrow-sided portions 66 of the screening plates 58 can be inserted. The narrow-sided portions 66 are hooked one inside the other at the narrow sides 62 by means of complementary positive-locking elements 68 so that the shielding 56 can be secured to the base member 40 by means of positive-locking alone.

Figure 4 is a section through a plug type connector 16 having a printed circuit board 70 which is inserted into the printed circuit board receiving member 38. It can be seen that the otherwise identically constructed printed circuit board contact portions 52 of the complementary plug contact modules 42, 44 are provided with a printed circuit board contact spring 72. By the printed circuit board 70 being inserted, the printed circuit board contact springs 72 are redirected in the direction of the contact portions 20 until their halves facing an articulation location 74 abut a stop 76 of the respective plug contact module 42, 44. Since the half of the printed circuit board contact spring 72 remote from the respective articulation location 74 remains free, the abutment thereof against the stop 76 increases only the resilient rigidity, but not the movability thereof. Consequently, an electrically conductive contact is achieved with the printed circuit board contact spring 72 not only by means of the articulation location 74, but also by means of the stop 76.

In order to optimise the signal transmission between the plug contact modules 42, 44 and the printed circuit board 70, structural measures are carried out in particular at the side of the printed circuit board, for example, by means of a stripline design.

In the embodiment of Figure 4, the signal path 48 extends in the region between the plug contact modules 42, 44 over the printed circuit boards 70, which is indicated by the short dashes of the signal path in this portion in Figure 4.

In Figure 4, it can further be seen that the socket contacts 46 are arranged so as to be recessed in the plug face 28. In order to contact the socket contacts, it is consequently necessary for the contact blades 34 to be inserted into the recesses 22 which are in alignment with the socket contacts 46 in the insertion direction 18.

If, as shown in Figure 2, a plurality of plug type connectors 16 are laterally connected, the arrangement of plug contact modules 44, 42 illustrated in Figure 5 is produced along the signal path 18. In Figure 5, the printed circuit board 70 and the shield 56 with the base member 40 are omitted in order to open up the view of the plug contact modules 42, 44. As can be seen, the contact blades 34 extend into the contact sockets 46. In the region of the printed circuit board contact portions 52, the signal path 48 is again illustrated with broken lines in Figure 5 since the signals can extend via a printed circuit board (not shown).

Two plug contact modules 42, 44 which are constructed so as to be able to be laterally connected form a plug contact arrangement 78.

In addition to the structural measures for transmitting frequencies in the gigahertz range via a plug contact arrangement 78 along the signal path 38, an improvement of the signal quality can also be achieved by means of an advantageous occupation of plug contact arrangements 78 which are located beside each other. It is thus possible to separate a plurality of independent pairs of differential channels +TX/RX and -TX/RX in each case by means of earth pins GND in order to increase the crosstalk attenuation and to be able to better control the impedance. This is advantageous, particularly in connection with a shield 56. With reference to Figures 6 and 7, a plug contact module 44 is now described whose contact portion 20 is provided with a substantially plate-like or disc-like contact blade 34. The plug contact module 44 is produced from a preferably punched and folded or tacked metal sheet 80 of constant material thickness 82. In the region of the contact blade 34, two layers 84 are preferably connected over the whole surface and at the flat sides thereof, each layer 84 forming at its outer side a preferably flat contact face 86. The material thickness 87 of the contact blade 34 is consequently twice as great as the material thickness 82 of the metal sheet 80.

At least in the insertion direction 18, preferably continuously, the contact blade 34 is provided at the edges at both sides with a chamfer 88, which extends away from the contact faces 86 over at least half of the material thickness 82 of a layer 84. The height of the contact blade 34, measured between two free edges and transversely relative to the signal path 48, in Figure 6 parallel with the insertion direction, is given the reference numeral 89.

The contact faces 86 each terminate at a shoulder 90, at which the plug contact module 44 is expanded with respect to the contact blade 34. The layers 84 continue beyond the shoulders 90 in an extension portion 92, in which the layers 84 are spaced further apart than in the contact blade 34. In the extension portion 92, the layers 84 extend as in the contact blade 34 in a linear manner and parallel with each other. A modification of the path of the layers 84 in the direction of the signal path 38 takes place only in the region of the shoulders 90.

In the extension portion 92, the layers 84 of the metal sheet 80 form two mutually parallel lateral walls 94. For reinforcement, the two lateral walls 94 are connected to each other at a narrow side 96 of the plug contact module 44 by means of a curved reinforcement member 98, which preferably extends over the entire length of the extension portion. As shown in Figure 6, the articulation location 74 for the printed circuit board contact spring 72 may be arranged at the end of the curved reinforcement member 98 opposite the contact portion. The curved reinforcement member 98 consequently continues as a printed circuit board contact spring 72. In the printed circuit board contact portion 52 at the end of the plug contact module 44 remote from the contact portion 20, the lateral walls 94 are extended towards the printed circuit board contact spring 72 and form the stop 76 which is constructed in the direction of the printed circuit board contact spring in such a manner that the spring fits tightly in a planar manner in the deflected state. The stop 76 is arranged in the region of the first half of the printed circuit board contact spring 72 so that the second half with the free end 100 remains movable in the direction towards the contact portion 20. In the region of the free end 100, the printed circuit board contact spring 72 is provided with a curvature 102 which is directed away from the contact portion 20. Opposite the free end 100, with the curvature 102, the stop 76 does not continue so that a recess 104 is formed by the lateral walls 94 of the extension portion. The free end 100 with the curvature 102 can still be deflected in the direction towards the contact portion 20 when the region located closer to the articulation location 74 is already in abutment against the stop 76.

In Figures 8 and 9, a plug contact module 42 having a contact portion 20 which is constructed as a socket contact 46 is illustrated from two different perspectives. The plug contact module 42 is, in the same manner as the plug contact module 44, produced from a metal sheet 80 with a material thickness 105. The material thickness 105 of the metal sheet of the plug contact module 42 preferably corresponds to the material thickness 82 of the plug contact module 44.

At the end of the plug contact module 42 opposite the contact portion 20 is the printed circuit board contact portion 52 which is constructed in a substantially identical manner to the printed circuit board contact portion 52. With regard to the function and configuration of the stop 76 and the printed circuit board contact spring 72 and the recess 104, reference is consequently made for the sake of brevity to the explanations relating to Figures 6 and 7. The contact portion 20 of the plug contact module 42 has two contact members 106 which each extend from a member base 108 to a free end 110 preferably in a linear manner. The contact members 106 delimit a contact blade receiving member 112 at both sides in the direction transverse relative to the insertion direction 18. The contact members 106 have a material thickness 111 which is preferably equal to the material thickness 105 in the entire plug contact module 42.

At the free ends 110, the plug contacts 106 may be extended at least at one side, but preferably at both sides, in the insertion direction 18 and have contact plates whose portions which are extended in the insertion direction 18 and which protrude beyond the contact springs 106 are inclined relative to the contact springs 106 and extend towards each other in the direction of the contact springs 106. Inclined introduction members 116 which facilitate the insertion of a contact blade 34 in the insertion direction into the contact blade receiving member 112 are thereby produced. The contact plates may be provided with a contact face 118 which is curved forwards in the direction of the blade contact receiving member 112 and which extends over at least the entire height 120 of the contact springs 106 and extends parallel with the insertion direction 18. The curved contact face 118 is preferably curved at least over the entire height 120 in a preferably barrel-like manner so that, with a flat contact face 86 of a contact blade 34, at least linear contact is produced over the height 120 of a contact member.

In the direction towards the printed circuit board contact portion 52, the contact members 106 continue in an extension portion 92, in which they are connected to each other by means of the curved reinforcement member 98. The curved reinforcement member 98 leads to the extension portion having greater rigidity than the contact members 106 which can be redirected transversely relative to the insertion direction 18. When viewed from the contact blade receiving member 112, the contact springs 106 extend at the other side of the member base 108 in a linear manner.

As can be seen from Figures 6 to 9, the plug modules 42, 44 are preferably constructed symmetrically relative to a centre plane 122 (cf. Figure 10) which extends in the direction of the signal path 48. The contact portions 20 are produced as contact blades 34 in both plug contact modules from two layers of sheet metal. In the contact blade 34, the layers are joined together and rest one on the other. In the socket contact 46, the layers are constructed with spacing from each other as contact members. At the other side of the contact portion, the layers extend continuously as far as the printed circuit board contact portion at the other end of the plug contact modules. In the extension portion 92, the layers form lateral walls 94 which are connected to each other by means of a curved

reinforcement member 98. The extension portion 92 has a U-shaped cross-section perpendicular to the signal path 38. If a plug contact module 42 and a plug contact module 44 are joined together with a plug arrangement 78 being formed, as illustrated in Figure 5, the illustration shown in Figure 10 is produced, when viewed in the insertion direction.

If the contact blade 34 is located in the contact blade receiving member 112, the two contact members 106 extend parallel with each other. The contact members 106 are then located in a plane with the lateral walls 94 of the adjacent extension portion 92 and preferably also the extension portion 92 of the other plug contact module. The mutual spacing of the lateral walls 94 of the connection portion 92 of one plug contact module 44 preferably further corresponds to the spacing of the lateral walls 94 of the other plug contact module 42. In this manner, the lateral outer faces 124 of one plug contact module 42 are in alignment with the lateral outer faces 126 of the other plug contact module 44. There is thus produced on the flat sides of the plug contact arrangement that preferably extend parallel with the insertion direction an aligned outer skin 128 which extends almost continuously between the two printed circuit board contact portions 52 at the two opposing ends of the plug contact modules 42, 44. In the insertion direction, the outer skin 128 formed by the lateral walls 94 and the contact members 106 has a preferably constant height 89, 120 which extends continuously as far as the two printed circuit board contact portions 52 via the connection location between the contact blade 34 and the contact members 106. The material thickness of the lateral walls 94 and the contact members 106 is constant in the direction between the two printed circuit board contact portions since a metal sheet 8 of the same material thickness 82 is preferably used for both plug contact modules 42, 44. At each location of the signal path 48 between the ends 50 of the plug contact modules 42, 44, an identical material thickness is thus provided in the line cross- section.

The lateral outer skin 128 of the plug contact arrangement 78 is interrupted only by a gap 130 between the free end 110 of the contact members 106 and the shoulders 90 opposite these free ends 110. This interruption is tolerable with regard to the transmitting signal quality for frequencies in the gigahertz range as long as the spacing between the shoulder 90 and the free end 110 is not greater than 1/10, but preferably not greater than 1/20 of the wavelength of the greatest frequency which is still intended to be transmitted in a reliable manner. Generally, this requirement is complied with when the spacing 132 between the free ends 110 of the contact members 106 and the shoulders 90 and the beginning of the extension portion 92 which is adjacent to the shoulders 90 is less than 1 mm.

In this configuration, the plug contact arrangement 78 forms for frequencies in the gigahertz range an almost continuous and linear waveguide between the two ends 50. At the same time, the plug contact arrangement 78 is sufficiently robust owing to the production of the plug contact modules 42, 44 exclusively from a metal material, preferably a punched metal sheet.

So that the contact members 106 extend parallel with each other when the contact blade is inserted into the contact blade receiving member 112 and there is provided on the contact faces 118 sufficient contact force which also enables reliable contacting of a contaminated contact blade 34, the contact members 106 may extend slightly towards each other in the direction of the contact receiving member 112 in the non-deflected rest state. If the contact blade 34 is pushed into the contact blade receiving member 112, the contact members 106 are pressed in a direction away from each other. Owing to the curved configuration of the contact faces 118 of the contact members 106 there is produced at least a linear contact with high surface pressure, which produces a reliable electrically conductive connection which also functions when the contact blades 34 are contaminated. Another aspect of the invention is illustrated in Figure 11, in which the extension portion 92 of one of the two plug contact modules (the plug contact module 44 is selected purely by way of example in this instance) is extended in the direction of the signal path 38. Of course, the extension portion 92 of the other plug contact module 42 or the extension portions 92 of both plug contact modules 42, 44 can also be extended. Owing to the homogeneous construction of the extension portion 92 which resembles that of a waveguide, it can be extended without losses of signal transmission quality. Owing to the extension of the extension portion 92, the plug contact modules 42, 44 can be adapted to different depths 7 of input/output modules 1 (cf. Figure 1). For example, the plug contact module 44 illustrated in Figure 11 can be used in an input/output module 1 which has triple the width and in which the plug type connector 16 has a corresponding depth 24.