WO2005122338A1

WO2005122338A1 - Contact arrangement for printed circuit boards

Info

Publication number: WO2005122338A1
Application number: PCT/EP2005/005190
Authority: WO
Inventors: Daniel Bischoff; Jürgen Hass
Original assignee: Tyco Electronics Amp Gmbh
Priority date: 2004-06-07
Filing date: 2005-05-12
Publication date: 2005-12-22
Also published as: DE102004027712B4; DE102004027712A1

Abstract

The invention relates to a contact arrangement (1) for a printed circuit board (40), which is provided with a housing (2, 4) and with a contact element (3). The housing surrounds an internal space (13) and is designed for attachment to the printed circuit board. At a distance from the printed circuit board, the housing comprises an access opening (30). The contact element comprises a printed circuit board contact portion accessible from outside the housing and designed to be electrically connectable with a conductor (43) of the printed circuit board. In the internal space of the housing there is arranged a plug-in contact portion of the contact element, which comprises at least one contact point (16) electrically connectable with a pin contact (41) extending through the access opening.

Description

CONTACT ARRANGEMENT FOR PRINTED CIRCUIT BOARDS

The invention relates to a contact arrangement having a housing enclosing an internal space, which housing is designed for attachment to a printed circuit board and comprises an access opening at a distance from the printed circuit board, and having a contact element, which comprises a printed circuit board contact portion accessible from outside the housing and designed to be electrically connectable with a conductor of the printed circuit board, and a plug-in contact portion arranged in the internal space of the housing, which plug-in contact portion comprises at least one contact point electrically connectable with a pin contact extending through the access opening. Such contact arrangements are known from the prior art. They are conventionally mounted on printed circuit boards, in order to form a plug-in connection to' the printed circuit board. For instance, US-A-5,616,044 describes and illustrates a contact arrangement which comprises a contact element in a housing. A contact arrangement which comprises a contact element in a housing is also illustrated and described in EP-A 1 418 647. The disadvantage of these known contact arrangements is that they cannot be used in printed circuit boards which are subject to severe vibration when in operation. Thus, for example, printed circuit boards subject to vibrational load are embedded in a thick layer of silicone, which covers the electronic components mounted on the printed circuit board and reduces the stress to which the attachment and electrical connection points are exposed in operation. The contact arrangements as described in the above-described prior art cannot be encapsulated in silicone by injection moulding or potted therein since the silicone penetrates into the interior of the housing and fixes or coats the contact point, such that an electrical connection to the pin contact can no longer be made. This is particularly disadvantageous because the electrical connection cannot be tested as early as on assembly of the printed circuit board, but rather only after completion and encapsulation by injection moulding or potting of the printed circuit board. The object of the invention is therefore to provide a contact arrangement for mounting for example on a printed circuit board which retains its functionality even on encapsulation by injection moulding or potting of the printed circuit board with a vibration-damping material such as silicone. This object is achieved for a contact arrangement of the above-mentioned type in that the housing takes the form of a receptacle which is impervious up to the access opening and a transitional portion of the contact element arranged between the plug-in contact portion and the printed circuit board contact portion extends around the edge of the access opening. This structurally surprisingly simple solution makes it possible to pot the printed circuit board in silicone or encapsulate it thereby by injection moulding up to the level of the access opening without the functionality of the contact element being impaired: since the housing takes the form of an impervious receptacle, no silicone can penetrate into the internal space of the contact arrangement. Since, in addition, the contact element extends with its transitional portion around the edge of the access opening or is bent around the edge, the receptacle does not comprise any holes or openings through which silicone can penetrate into the internal space. The receptacles found in the prior art comprise openings and holes through which the silicone is drawn by capillary action into the internal space of the housing, where it impairs the functioning of the contact element. The mutually independent configurations described in general below each constitute further developments of the solution according to the invention. The individual configurations may in particular be combined together in any desired combination. For instance, in one advantageous configuration, the receptacle may be shaped in one piece. Then, no connecting seams or weld points are present which have a tendency to result in leaks or, in particular in the event of a heavy vibrational load, breakage. To keep mould making for production of the receptacle as simple as possible, the receptacle may substantially comprise a base extending parallel to the printed circuit board and side walls extending preferably and substantially perpendicularly to the base and away from the printed circuit board. The access opening may face the base and be defined by the side walls. In the case of a receptacle with a round base, naturally only one side wall is present. In the case of contact arrangements subject to vibrational load or in the event of a change in temperature, relative motion may arise between the contact point of the contact arrangement and the conductor inserted into the contact arrangement and the pin contact attached thereto. The relative motion between pin contact and contact element results in fretting corrosion or abrasion, i.e. a high-resistance layer forms between the contact element and the pin contact. The high-resistance layer impairs electrical conductivity and signal transmission through the contact arrangement to the point of inoperability. Such abrasion between the pin contact and the contact element may be simply prevented, according to a further advantageous development, in that the at least one contact point is held in the housing so as to be resiliently displaceable about a neutral position. Owing to its resilient displaceability, the contact point may follow the movements of the pin contact, such that no relative motion and thus also no abrasion occurs any longer at the contact point between pin contact and contact element. The resiliently displaceable suspension of the contact point in the housing may be achieved in particular in that the contact element itself comprises a resiliently displaceable spring portion, which holds the contact point. In an advantageous configuration, this spring portion may be provided in the transitional area, since at this point forces introduced into the contact point of the pin contact may quickly lead to deformation of the transitional area due to the deflection of the contact element at the edge of the access opening. To increase the service life of the spring element under heavy vibrational loading, the transitional area may be curved in the form of an arc such that no peak stresses may form in the contact element. Of course, the transitional area may also comprise kinks, but these are disadvantageous in relation to fatigue strength insofar as the deformation stresses are. concentrated in the kinks and lead to breakage at these points. It is precisely in vibrationally loaded contact arrangements with a plurality of load changes, therefore, that as low-stress a configuration as possible of the contact element is advantageous, said configuration avoiding kinks, folds and unfavourably shaped or disposed holes with corners or small radii. To prevent the resilient suspension of the contact point from being overstretched and damaged during assembly and/or on removal of the pin contact from the contact arrangement, if the contact element initially follows the movement of the pin contact, limit stops may be provided on the housing, which cooperate with the contact element and limit the movement of the contact point. Thus, for example an insertion stop designed to cooperate with the contact element may be provided on the housing to restrict displacement of the contact point in a direction of insertion of the pin contact. In addition, a withdrawal stop designed to cooperate with the contact element may be arranged on the housing to restrict displacement of the contact point contrary to the insertion direction of the pin contact. The contact element may comprise a corresponding mating stop, which takes the form of a projection or a notch, for example, and cooperates with the withdrawal stop and/or insertion stop. Furthermore, mutually cooperating mounting stops may be provided on the contact element and on the receptacle to fix the position of the contact element in the assembly direction on insertion of the contact element into the housing. In this way, it is ensured that, on the one hand, the pin contact comes into contact with the plug-in contact portion and, on the other hand, in the case of resilient suspension of the contact point, the spring excursion provided for use is also present. To ensure the mobility of the contact point, in accordance with a further advantageous configuration, the contact element may be accommodated in the internal space or in the housing at a distance from the housing. To accommodate the pin contact, the plug-in contact portion may form an insertion slot opening towards the access opening and designed to be resiliently widenable by the pin contact. This measure makes it possible for the pin contact introduced into the insertion slot to be held in electrical contact with the plug-in contact portion and simply inserted and removed by the resilient restoring forces of the widened , insertion slot. In a further development, the insertion slot may take the form of two contact legs extending in the insertion direction and connected by a bend portion. In this configuration, the contact legs are forced apart, for example, if the pin contact is introduced between the contact legs. The bend portion ensures resilient suspension of the at least one contact point. The bend portion additionally allows relative motion of the two contact legs relative to one another, which again increases the resilience and reliability of the electrical contact. The bend portion is preferably curved substantially into an arc shape, to prevent the occurrence of peak stresses in the contact element and thus breakage of the contact element under an elevated load change frequency. By using two contact elements, at least two contact points are formed, which increases the reliability of the electrical connection. In order to simplify introduction of the pin contact into the insertion slot, the insertion slot may taper at least in part in the direction of insertion. The insertion slot may also be incorporated into the contact element, for example by providing the slot in the contact element itself. If, in addition, two contact legs are used in this configuration, which are each slotted, the plug-in contact portion is accordingly connected to the pin contact via four contact points since it is inserted into each of the two insertion slots. In order to fix the contact element to the housing, the contact element may comprise a retaining portion. In a further configuration, resilient suspension of the contact portion may be ensured in that the retaining portion is arranged in the area of the printed circuit board contact, such that the transitional area and the plug-in contact portion are not fixed and remain freely movable. This is the case, for example, when the retaining portion, viewed from the plug-in contact portion, is arranged on the other side of the transitional portion. The contact element may take the form of a one-piece, bent material strip, which is preferably punched from a metal sheet. In a side view, the contact element may be substantially M-shaped, wherein the two outer legs of the "M" form the printed circuit board contact portions and the contact legs form the middle area of the "M". An asymmetrical N-shaped configuration, in which two legs of the "N" form a contact slot, or a V-shaped configuration with only one contact leg are also feasible. For electrical connection to the printed circuit board, the printed circuit board contact portion may comprise at least one contact tongue projecting out of the housing, which contact tongue is preferably of bendable construction, so as to be able to use the same components to construct the contact arrangement both as a PIN and as an SMD version. In the case of the PIN arrangement, the contact tongue projects into an opening in the printed circuit board perpendicularly beneath the bearing surface when the contact arrangement is mounted on the printed circuit board, while in the SMD configuration the contact tongue is bent round parallel to the surface of the printed circuit board, to allow fitting of the connections on the printed circuit board. The printed circuit board contact portion may also comprise one or more contact tongues, for example two contact tongues, by giving it a forked construction. This measure may maintain the reliability of the electrical connection even when the number of load changes is high and reduce the forces on the solder points. To make the suspension of the contact point suspension as resilient as possible, it is advantageous for the point of attachment of the contact element to be arranged as close as possible to the ends, for example between the two contact tongues. In this way, as long as possible a portion of the contact element extends between the at least one contact point and the spring portion, so making the suspension more flexible. The flexibility of the suspension may additionally be determined by the shape of the contact element, for example by making the distance between the contact point and the spring portion as large as possible. In this way, when a force acts on the contact point, a greater moment is introduced into the spring portion, which leads to greater displacement. When producing a printed circuit board, the contact arrangements according to the invention are conventionally automatically attached to the printed circuit board by automatic component insertion machines and only connected electrically in a subsequent step. In order to fix the position of the contact arrangement on the printed circuit board prior to production of the electrical connections, the housing may comprise a bearing surface which in the assembled state lies on the printed circuit board and thus determines the position of the contact arrangement perpendicularly relative to the printed circuit board. In addition, the contact arrangement may comprise a retaining peg, which extends away from the bearing surface in the direction facing away from the access opening. The retaining peg serves to keep the contact arrangement secure during transportation after mounting on the printed circuit board but before final attachment. To this end, the retaining peg is inserted into a corresponding receiving opening in the printed circuit board. The retaining peg may be provided with knobs and/or ribs, to form an interference fit with the opening in the printed circuit board. The retaining peg may be internally hollow and connected with the internal space in the housing and accommodate at least one portion of the contact element, so reducing the structural height of the contact arrangement above the printed circuit board. To make it easier for an automatic component insertion machine to place the contact arrangement onto the printed circuit board, a "pick and place" method may be used, from a pallet, or the contact element may be delivered as strip material with mountable housing. For instance, the contact arrangement may be placed at any point on the PCB by means of X/Y heads. In order to protect the internal space of the housing from contamination, the housing may comprise a lid element placed onto the access opening, in which element there is provided an insertion opening which opens onto the internal space of the housing.

The dimensions of the insertion openings are conformed to the dimensions of the pin contact, such that only a small gap arises between the insertion opening and the pin contact through which only little or no dirt can enter the internal space. The insertion opening may taper in the insertion direction, such that the pin contact is guided into the plug connector and to the at least one contact point. The lid element may preferably be connected to the receptacle by catch means. When using a lid element, the transitional portion may pass out of the internal space of the housing between the lid element and the housing. To this end, an opening is formed between the receptacle and the lid element, when these are in the assembled state, through which the contact element projects. To this end, the lid element may be recessed in the area of the transitional area of the contact element. So that the contact point remains mobile, the transitional area is arranged at a distance from the lid element and/or housing., The lid element may in particular be saddle-shaped, wherein the two legs comprise the catch elements and the transitional area is arranged between the two legs. In addition, the withdrawal stop may be constructed on the lid element, which is particularly advantageous when the lid element is placed on the receptacle in the pin contact insertion direction. In order to distribute the forces evenly onto the contact tongues, the contact element and the pin contact, the contact arrangement is preferably constructed symmetrically relative to two planes of symmetry positioned perpendicularly to one another, wherein one of the planes of symmetry preferably extends through the centre line of the contact element. A further effect of this measure is that the resilient suspension of the contact point is not loaded in one-sided manner. If the contact arrangement is configured symmetrically, two printed circuit board contact portions may be provided on two opposing sides. In this case, the plug-in contact portion is likewise of symmetrical construction and defined by two transitional portions. The invention is explained below, by way of example, with reference to one embodiment and to the drawings. The embodiment described below may be modified in accordance with the above statements, by omitting individual features and adding other features if the advantages associated with these features are respectively unimportant or necessary for the particular application. In the Figures: Fig. 1 is a schematic perspective representation of a contact arrangement according to the invention; Fig. 2 is an exploded view of components of the embodiment of Fig. 1, in a schematic perspective representation; Fig. 3 is a schematic perspective representation of a contact element of the embodiment of Fig. 1; Fig. 4 is a schematic perspective representation of a housing part of the embodiment of Fig. 1; Fig. 5 is a schematic perspective representation of a lid element of the embodiment of Fig. 1 ; Fig. 6 is a schematic sectional view of the embodiment of Fig. 1, in a mounted state. Fig. 1 is perspective view of a contact arrangement 1. The contact arrangement 1 comprises a receptacle-shaped housing part 2, a contact element 3 and a lid element 4. The contact arrangement 1 and its constituent parts 2, 3, 4, as illustrated in Fig. 1, are symmetrical both relative to a plane of symmetry S_t and a plane of symmetry S₂, wherein the two planes of symmetry Si and S₂ are perpendicular to one another and extend parallel to the side walls of the housing part 2, which is cuboid in this case. In the description which follows, only one side, relative to the plane of symmetry Si, of the contact arrangement 1, facing the viewer in Fig. 1, will be examined due to the at least one-fold symmetry of the contact arrangement 1. The structure of the other side is clear from its symmetrical nature. The contact arrangement 1 shown in Fig. 1 is conventionally mounted on a printed circuit board (not shown). The housing part 2 comprises to this end a bearing surface 5, which may be brought to rest on a surface of the contact board. A retaining peg 6 extends from the bearing surface 5, on the side thereof remote from the contact element 3, and is provided with a clamping means 7, such as ribs or knobs. The housing part 2 is in one piece and preferably made of seamless plastics material, for example in a casting process. It does not comprise any openings in the base and side areas. At least one contact tongue 8 projects from the housing part 2, there being a total of four contact tongues 8 in the embodiment illustrated in Fig. 1. The contact tongues 8 extend parallel to the bearing surface 5 at roughly the level thereof relative to a longitudinal axis L of the contact arrangement 1. To this end, the contact tongue 8 is bent away from the housing part 2. The contact tongues comprise a passage opening in the middle. A variant V of the contact arrangement 1 indicated in an area surrounded by dash- dotted lines may comprise contact tongues 8', which extend parallel to the longitudinal direction L and perpendicular to the bearing surface 5. The contact element 3 extends outside the housing part 2 roughly parallel to the longitudinal axis L in each case along a side wall 9 of the housing part 2 from the upper area of the contact arrangement 1 remote from the printed circuit board to the printed circuit board. At the upper edge of the housing part 2, the contact element 3 continues into an internal space of the housing part 2. The lid element 4 is placed onto the upper end, opposite from the bearing surface 5, of the housing part 2 and is substantially saddle-shaped. A catch means 10 on the housing part 2 and on the lid element 4 holds the lid element 4 and the housing part 2 together. The lid element 4 is recessed on the side of the contact element 3. On the end face 11 lying in the longitudinal direction L of the contact arrangement, the lid element 4 is provided with an insertion opening 12 running parallel to the longitudinal direction L. As is clear from Fig. 2, the contact element 3 is fitted together with the housing part 2 in a first assembly direction Mi, wherein portions of the contact element 3 are accommodated in an internal space 13 in the housing part 2. The lid element 4 is positioned on the housing part 2 in an assembly direction M₂, wherein the assembly directions Mi and M₂ are identical in the embodiment described here.. The contact element 3 may be fitted together first of all with the lid element 4, but preferably with the housing part 2. The structure of the contact element 3 will now be explained in more detail with reference to Fig. 3. The contact element 3, as preferably are also the other components of the contact arrangement, is preferably symmetrical both relative to the plane of symmetry Si and to the plane of symmetry S₂ extending symmetrically thereto and comprises a substantially M-shaped structure in side view. The contact element 3 comprises a printed circuit board contact portion 14, which, as is clear from Fig. 1, is arranged outside the housing part 2 and extends in the longitudinal direction L of the contact arrangement. In the housing part 2 there is arranged a plug-in contact portion 15 of the contact element 2, which is designed to be electrically connectable with a pin contact. For electrical connection with the pin contact, at least one contact point 16 is provided on the plug-in contact portion 15, by means of which contact point 16 the pin contact is contacted when inserted. Between the printed circuit board contact portion 14 and the plug-in contact portion 15 there extends a transitional area 17 which, as Fig. 3 shows, is curved in the shape of an arc. The printed circuit board contact portion 14 and the plug-in contact portion 15 extend parallel to one another, such that the transitional area is curved through an angle of around 180°. Next to the contact tongues 8, the printed circuit board contact portion 14 forms a retaining portion 18, by which the contact element 3 may be attached to the housing 2. In the embodiment described, the retaining portion 18 comprises friction elements 19 in the form of saw teeth at its edges, wherein the flat side of the saw teeth points in the assembly direction Mi. The printed circuit board contact portions 14 each forming one end of the contact element 3 are substantially fork-shaped, wherein the contact tongues are located on two legs 20 of the fork extending parallel to one another. The retaining portion 18 extends between the legs 20 and parallel thereto. Between the retaining portions 18 and the legs 20 there is formed a mounting stop 18a, which points in the assembly direction

The plug-in contact portion 15 comprises two contact legs 21, which extend parallel to one another and are connected together by a preferably arc-shaped bend portion 22. The contact legs 21 are accommodated in the receptacle 2. The contact element 3 forms an insertion slot 23, in which a pin or tab contact (not shown) may be accommodated and connected to the contact element 3. In a first variant, the insertion slot may be formed between the two contact legs 21, such that the bend portion 22 forms the bottom of the insertion slot. However, in order to increase the retaining force of the contact arrangement and thus contact reliability, the variant illustrated in Fig. 3 is preferred. The contact element 3 is therefore of slotted construction and may be provided with one or two slots 23 a, 23b which extend in the longitudinal direction of the contact element 3 and together form the insertion slot 23. When using two slots, as in the embodiment of Fig. 3, the slots preferably end before the bend portion 22, in order not to impair the stability of the contact element 3. The ends of the slots 23 are rounded. The end of the insertion slot 23 in the region of the opening is located in the transitional area 17, such that the slot opens in a direction E of insertion of a plug-in contact. In the insertion direction E, the insertion slot 23 is provided with a lead-in bevel

24, by means of which the width of the slot tapers towards the contact point 16. Downstream of the contact point 16 in the insertion direction E, the insertion slot 23 may widen out again. The contact point 16 is arranged relatively near to the opening of the slot

23 in the insertion direction E. In the plug-in contact portion 15 there is additionally provided a projecting limit stop 25, which comprises an extraction stop 26 directed contrary to the insertion direction E and an insertion stop 27 pointing in the insertion direction E. The contact element 3 is formed in one piece as a material strip from a sheet metal strip which has been punched and then bent into shape. Fig. 4 is a perspective representation of the housing part 2. As is clear therefrom, the housing part 2 takes the form of an impervious receptacle, which is surrounded all around by side walls 9. At the bottom, the housing part 2 is closed by a bottom (not visible in Fig. 4). The upper ends of the side walls 9 remote from the bearing surface 5 define an access opening 30 to the internal space 13 of the housing part 2, which is likewise arranged at a distance from the printed circuit board. The access opening 30 is preferably the only opening of the receptacle 2, or at least no other opening should be situated between the access opening 30 and the bearing surface. A recess 31 is provided at two opposing areas of the side walls 9, in which recess the height of the side walls, measured from the bearing surface 5 in the direction of the access opening 30, is somewhat reduced. The transitional area 17 of the contact element 3 extends as shown in Fig. 1. The housing part 2 is provided with a retaining device 32 on the side of the printed circuit board contact portion 14. The retaining device 32 comprises an insertion opening 33 extending in assembly direction Mi, in which opening 33 the retaining portion 18 of the contact element 3 may be frictionally engaged. To this end, the internal width of the insertion opening 33 is somewhat smaller, in the direction parallel to the side wall associated with the insertion opening 33, than the width of the retaining portion 18 in the plane of the contact element 3, such that the clamping means 19 in the form of saw teeth comes into engagement with the walls of the insertion opening 33 and fixes the contact element 3 in the area of the printed circuit board contact portion 14 by frictional engagement. Instead of a frictional engagement, it is of course also possible to use a catch or locking means. The side walls defining the insertion opening 33 in the direction parallel with the associated side wall 9 form with their face directed contrary to the assembly direction Mi a mating stop for the insertion stops 18a of the contact element 3. When mounting the contact element 3 in the housing part 2, the depth to which the retaining portion 18 may be inserted into the insertion opening 33 is defined by the insertion stop 18a meeting the mating stop 34. On both sides of the insertion opening 33 there are provided groove- or bore- shaped receptacles 35, likewise extending in the assembly direction Mi, for the legs 20 of the printed circuit board contact portion 14. Parallel to the associated side wall and at a distance therefrom there extends a shield 36, which supports the leg 20 in the direction perpendicular to the associated side wall 9 and defines the receptacles 35 in said direction. If the variant V illustrated in Fig. 1 with reference numeral 8 is used, the shield 36 , is used as a counter-support, for bending the contact tongue 8 at right angles to the leg 20 and parallel to the bearing surface 5. Therefore, in the direction perpendicular to the bearing surface 5, the lower end of the shield 36 is spaced from the bearing surface 5 roughly by the thickness of the contact element, such that the lower side of the bent contact tongue 8 is flush with the bearing surface 5. During the assembly process illustrated schematically in Fig. 2, the contact element illustrated in Fig. 3 is inserted into the housing part 2 in such a way in the assembly direction Mi that the plug-in contact portion 15 with the two legs 21 and the bend portion 22 therebetween is inserted through the access opening 30 into the internal space of the housing part 2. After a given insertion depth, the contact tongues 8 engage in the receptacles 35 associated therewith. The retaining portion 18 is then inserted into the insertion opening 33. Once the insertion stop 18a strikes against the limit stop 34 on the housing, the assembly process is complete. In the internal space 13 of the housing part 2 there is provided an insertion stop directed contrary to the insertion direction E of the pin contact (c.f. Fig. 4). When the contact element 3 has been mounted in the housing part 2, the insertion stop 37 faces the limit stop 27 on the contact element 3 at a distance therefrom. Fig. 5 is a perspective representation of the lid element 4, looking down on the end face 11 facing contrary to the assembly direction M₂. As is clear from this representation, the insertion opening 12 tapers in the insertion direction E. The contour of the insertion opening 12 corresponds to the shape of the pin contact to be used with the contact arrangement according to the invention. A tab connector is used as pin contact, for example, such that the contour of the insertion opening 12 forms a rectangle. In the insertion direction E, the insertion opening 12 is aligned with the slot 23. On the side facing the internal space 13, the lid element 12 forms a withdrawal stop^" 38 pointing in the insertion direction E. In the assembled state, the withdrawal stop

38 comes to face the limit stop 26 formed by the contact element 3, at a distance therefrom. Fig. 6 is a schematic section representation along the plane of symmetry Si of Fig.

1, wherein the contact arrangement 1 is shown mounted on a printed circuit board 40, with an inserted pin contact 41 of a plug connector (not shown). As is clear from Fig. 6, the retaining peg 9 is inserted through a corresponding opening in the printed circuit board 40. The peg 9 is hollow on the inside and accommodates at least a portion of the contact element 3, in the present example the lower area of the plug-in contact portion 15 with the bend portion 22. To protect against vibrations, on one of its two sides the printed circuit board 40 is encapsulated by injection moulding in a silicone layer or potted therein. The silicone layer 42 extends as far as just below the access opening 30 of the receptacle-type housing part 2. The silicone 42 cannot penetrate through the seal of the internal space 13 of the housing part 2. Since the contact element 3 passes over the edge of the access opening 30, the silicone layer 42 may be made sufficiently thick reliably to cover and protect all the structures on the printed circuit board 40. It is additionally clear from Fig. 6 how the pin contact 41 is inserted into the insertion slot 32 and contacted at the contact points 16. The contact points 16 are suspended in oscillating manner, since the contact element 3 is spaced from the housing, as formed by the housing 2 and the lid element 4, in the internal space 13 and is merely held by the retaining means 18. As a result of the oscillating mounting of the contact points 16, relative movements between the pin contact 41 and the contact element 3 are compensated. The transitional area 17 here serves as a spring element, which counteracts displacement of the contact point 16 out of its neutral position and generates a resilient restoring force directed against and counteracting the displacement. Overstretching and/or plastic deformation of the contact element 3 during operation is prevented by the limit stops 26, 27, 37, 38. Such a risk of oversfretching arises in particular during insertion of the plug connector and removal of the plug connector. When inserting the plug connector, the contact point 16 moves in the insertion direction E, such that the limit stop 27 meets the insertion stop 37 on the housing and restricts displacement. When removing the pin contact 41, the contact point 16 moves contrary to the insertion direction E, such that the limit stop 26 on the contact element side meets the limit stop 38 of the housing. Because of the two slots 23 a, 23b in the contact legs 21, which together form the insertion slot 23, the pin contact 41 is contacted at at least four contact points by the contact element 3. Modifications of the above-described embodiment are possible. For instance, it is possible in particular to dispense with symmetry of the contact arrangement and for the contact element to comprise only a single contact leg 21, which is connected via the transitional area 17 to the printed circuit board contact portion located outside the housing 2, 4. For example, the contact element may be V- or X-shaped, with one or two contact legs, i.e. just one printed circuit board contact portion. It is possible to dispense with the peg 9, if it is not essential to retain the contact arrangement securely immediately after insertion of components into the printed circuit board. Finally, a separate lid element 4 and the withdrawal stop 38 may be provided on the housing part 2.

Claims

1. A contact arrangement (1) having a housing (2, 4) enclosing an internal space (13), which housing is designed for attachment to a printed circuit board (40) and comprises an access opening (30) at a distance from the printed circuit board, and having a contact element (3), which comprises a printed circuit board contact portion (14) accessible from outside the housing and designed to be electrically connectable with a conductor (43) of the printed circuit board, and a plug-in contact portion (15) arranged in the internal space of the housing, which plug-in contact portion comprises at least one contact point (16) electrically connectable with a pin contact (41) extending through the access opening, characterised in that the housing (2, 4) takes the form of a receptacle (2) which is impervious up to the access opening and a transitional portion (17) of the contact element (3) arranged between the plug-in contact portion (15) and the printed circuit board contact portion (14) extends around the edge of the access opening (30).

2. A contact arrangement (1) according to claim 1, characterised in that the receptacle (2) is shaped in one piece.

3. A contact arrangement (1) according to claim 1 or claim 2, characterised in that the at least one contact point (16) is held in the housing (2, 4) so as to be resiliently displaceable about a neutral position.

4. A contact arrangement (1) according to claim 3, characterised in that the contact element (3) comprises a resiliently displaceable spring portion (17a) between the contact point (16) and a portion by which the contact element (3) is attached to the housing (4).

5. A contact arrangement (1) according to claim 4, characterised in that the spring portion (17a) is provided in the transitional area (17).

6. A contact arrangement (1) according to any one of claims 3 to 5, characterised in that on the housing (2, 4) there is provided an insertion stop (37) designed to cooperate with the contact element (3) and directed contrary to an insertion direction (E) of the pin contact (41), by means of which insertion stop the displacement of the contact point (17) in the insertion direction (E) is restricted.

7. A contact arrangement (1) according to any one of claims 3 to 6, characterised in that on the housing (2, 4) there is provided a withdrawal stop (38) cooperating with the contact element (3) and directed in the insertion direction (E), by means of which withdrawal stop the displacement of the . contact point (16) contrary to the insertion direction (E) is restricted.

8. A contact arrangement (1) according to claim 6 or claim 7, characterised in that the contact element (3) comprises at least one mating stop (25, 26).

9. A contact arrangement (1) according to any one of the preceding claims, characterised in that the contact element (3) is accommodated in the internal space (13) at a distance from the housing (2, 4).

10. A contact arrangement (1) according to any one of the preceding claims, characterised in that the transitional portion (17) is curved to form an arc.

11. A contact arrangement (1) according to any one of the preceding claims, characterised in that the plug-in contact portion (15) forms an insertion slot (23) opening towards the access opening (30) and designed to be resiliently widenable by a pin contact (41).

12. A contact arrangement (1) according to claim 10, characterised in that the insertion slot (23) is formed by two contact legs (21) extending in the insertion direction

(E) and connected by a bend portion (22).

13. A contact arrangement (1) according to claim 11 or claim 12, characterised in that the insertion slot (23) tapers at least in part in the insertion direction (E).

14. A contact arrangement (1) according to any one of claims 11 to 13, characterised in that the insertion slot (23) is incorporated into the contact element.

15. A contact arrangement (1) according to any one of the preceding claims, characterised in that the contact element (3) comprises a retaining portion (18), which is fixed to the housing (2, 4).

16. A contact arrangement (1) according to claim 15, characterised in that the retaining portion (18) is arranged in the area of the printed circuit board contact portion

(14).

17. A contact arrangement (1) according to claim 15 or claim 16, characterised in that the retaining portion (18) is arranged on the other side of the transitional portion (17) when viewed from the plug-in contact portion (15).

18. A contact arrangement (1) according to any of the preceding claims, characterised in that the contact element (3) is designed as a one-piece, bent material strip.

19. A contact arrangement (1) according to any one of the preceding claims, characterised in that the printed circuit board contact portion (14) comprises at least one bendable contact tongue (8) projecting from the housing (2, 4).

20. A contact arrangement (1) according to any one of the preceding claims, characterised in that the contact element (3) is substantially M-shaped in side view.

21. A contact arrangement (1) according to any one of the preceding claims, characterised in that the printed circuit board contact portion (14) is of forked design, with two contact tongues (8).

22. A contact arrangement (1) according to claim 14 and claim 21, characterised in that the retaining portion (18) is arranged between the two contact tongues (8).

23. A contact arrangement (1) according to any one of the preceding claims, characterised in that the housing (2, 4) comprises a bearing surface (5) which in the assembled state may be positioned on the printed circuit board (41) and in that a retaining peg (9) is provided, which extends away from the bearing surface (5) in the direction facing away from the access opening.

24. A contact arrangement (1) according to claim 23, characterised in that the retaining peg (9) is hollow on the inside and accommodates at least one portion of the contact element (3).

25. A contact arrangement (1) according to any one of the preceding claims, characterised in that the housing (2, 4) comprises a lid element (4) placed onto the access opening, in which element there is provided an insertion opening (33) opening onto the internal space (13).

26. A contact arrangement (1) according to claim 24, characterised in that the transitional portion (17) passes out of the internal space (13) between the lid element (4) and the receptacle (2).

27. A contact arrangement (1) according to claim 25, characterised in that the transitional area (17) is arranged at a distance from the lid element (4) and/or receptacle (2).

28. A contact arrangement (1) according to any one of claims 25 to 27, characterised in that the withdrawal stop (38) is provided on the lid element (4).

29. A contact arrangement (1) according to any one of claims 25 to 28, characterised in that the lid element (4) is recessed in the area of the transitional area (17).

30. A contact arrangement (1) according to any one of the preceding claims, characterised in that the contact arrangement (1) is constructed symmetrically relative to two planes of symmetry (Si, S₂) positioned peφendicularly to one another.