The invention relates to an electric contact for an electrical plug connection which is to be plugged together in a plugging direction, with a receptacle for a complementary contact pin, the receptacle opening against the plugging direction and comprising a contact surface for contacting the complementary contact pin. The invention also relates to an electrical plug connection with a first sleeve-shaped contact and a second pin-shaped contact that is complementary to the first contact, both of which contacts can be plugged together in a plugging direction and comprise contact surfaces.

Such contacts are known, for example in the form of contact sleeves into which a pin- or tab-shaped contact pin is inserted. In the case of such contacts, one aim is to achieve a stable contact resistance. This requires a high pressing pressure between the contact surfaces, in order to break through possible layers of corrosion or foreign matter and establish a direct contact between the electrically conductive materials of the contacts. Such a pressing pressure however entails high plugging forces, so that such contacts can only be plugged together with a high expenditure of force. If high currents are to be transferred by way of the contact surfaces, they should lie on one another over as large a surface area as possible, in order to lower the contact resistance. However, with the contact surfaces lying on one another over a large surface area, the frictional resistance during the plugging together increases, so that once again higher contact forces are necessary.

In view of these conflicting requirements, the invention is based on the object of creating an electric contact that makes a stable and low contact resistance possible, with at the same time low plugging forces and great longevity. This object is achieved according to the invention for the electric contact mentioned at the beginning by at least one roller contact body made of an electrically conductive material that projects into the receptacle and forms part of the contact surface respectively being rotatably held on at least two opposing sides of the receptacle. In the case of the electric plug connection mentioned at the beginning, according to the invention one of the contact surfaces of the rotatable roller contact bodies is formed from an electrically conductive material. The roller contact bodies on the one hand provide a small bearing surface, so that even with low contact forces the pressing pressure is great enough to break through layers of corrosion and foreign matter. On the other hand, the roller contact bodies can roll, so that lower plugging forces are necessary. At the same time, as a result of the rolling movement, the removal of material from the contact surface of the complementary contact pin is small, so that even after a very high number of plugging cycles the electric contact itself has only a very low amount of wear.

The invention can be further improved by the following designs, which are each advantageous in themselves and can be combined with one another in any way desired.

Thus, the roller contact bodies are preferably produced from a conductive material with a conductivity of at least 30 S/m, in order to pass on with as little loss as possible the current conducted away from the contact surface of the complementary contact pin. The conductive material may for example comprise at least one of the metals gold, silver, aluminium and copper.

The complementary contact pin may be a tab- or pin-shaped contact. In the case of a tabor blade-shaped contact, the sides on which the roller contact bodies are located are preferably the flat sides of the receptacle.

The roller contact bodies may be spheres, cones, truncated cones, barrels, needles and/or cylinders. The contact surface is preferably formed exclusively by the roller contact bodies, in order to keep the plugging forces and the amount of wear as low as possible.

The roller contact bodies may be rotatable about at least one axis of rotation oriented transversely in relation to the plugging direction. Their rolling surface may in such a case be movable at least along the plugging direction in the region of the contact surface as a result of the rotating movement, in order to be able to roll along the plugging direction during insertion. Further directions of movement of the rolling surface with a

correspondingly differently oriented axis of rotation in the region of the contact surface may make compensating movements between the two contacts possible, for example in an environment that is subjected to vibrational loading. Thus, for example, the axes of rotation may be aligned along the plugging direction, in order to allow relative movements between the contacts transversely in relation to the plugging direction. This is of advantage for example in environments that are subjected to vibrational loading. The roller contact bodies may be mounted rotatably about a number of axes of rotation simultaneously. Thus, spherical roller contact bodies may be held rotatably in each direction.

According to a further advantageous design, the roller bodies may be attached to at least one slide that is movable along the plugging direction. The slide may form a roller bearing cage, which holds the roller contact bodies. Such a slide makes the assembly of the contact easier, because the roller contact bodies can be preassembled on the slide.

The slide may be displaceable between two end positions along the plugging direction, in particular together with the inserted contact pin. In this case, the speed of the slide may differ from the plugging speed of the contact pin.

The slide may form the receptacle of the contact and have for this purpose a sleeve- or box-shaped portion. The receptacle may be open right through in the plugging direction.

The form of the inner cross section of the receptacle transversely in relation to the plugging direction depends on the form of the plugging contact to be used. The inner cross section may be round, in particular circular, or polygonal, in particular rectangular. In the plugged-together state, the contact pin may be at least partially supported on the slide, in particular on the roller contact bodies. In addition, the slide may also form a bearing support.

In the plugged-together state, the contact pin may protrude out of the slide on both sides along the plugging direction.

The plugging operation can be made easier if the roller contact bodies are arranged exclusively in one half that is against the plugging direction, in particular at the insertion opening of the receptacle of the slide that is against the plugging direction. They may in particular be arranged at the end of the slide that lies at the insertion opening of the receptacle.

In order to keep the production costs low and provide a defined current path by way of the roller contact bodies, the slide is preferably produced from a non-conductive material, such as plastic, in particular by injection moulding.

The housing may form at least one pressing spring for the roller contact bodies, and/or there is a pressing spring between the housing and the roller contact bodies. The pressing spring lies against the roller contact bodies and is designed as resilient transversely in relation to the plugging direction, in a direction away from and towards the receptacle. With the contact pin fully inserted, the at least one pressing spring is elastically deflected to produce the contact force.

The roller contact bodies may be accommodated in clearances, in which they are for example held in a form-fitting manner. For this purpose, the roller contact bodies may simply be pressed into the clearance respectively assigned to them. The clearances may be provided in a housing or in a slide, if such a slide is present.

At least a portion of the slide may be accommodated in a housing. The housing serves as protection and in particular as a guide for the slide. The housing may comprise groove- shaped raceways for the roller contact bodies, which extend in particular along the plugging direction. The raceways may be designed as resilient transversely in relation to the plugging direction, in a direction towards and away from the receptacle, in order to form the pressing spring for the roller contact body running in the raceway. According to a further design, the housing serves as in the case of the known contact sleeves without roller contact bodies for conducting the current away. For this purpose, it is preferably produced from a conductive material, in particular from a conductive material as described above.

The slide may comprise at least one driver for the contact pin, the driver projecting into the receptacle. Such a driver may be used for the purpose of moving the slide in the course of the inserting movement by the contact pin inserted into the receptacle. This is meaningful in particular whenever the roller contact bodies only lie against the pin contact and do not bear against a surface on the opposite side, that is to say roll exclusively on the pin contact. The drivers may be located on the sides of the receptacle against which the roller contact bodies lie. These are for example the flat sides of the contact. Of course, drivers may also be arranged or only be arranged on the narrow sides.

In a further advantageous design, in at least one release position of the slide the driver may have been moved out of the receptacle. If the driver has been moved out of the receptacle, the receptacle is free. This makes it possible for the contact pin to be inserted through the slide.

The driver may in particular have been moved out of the receptacle over a portion of the movement of the slide that extends up to an end position of the movement of the slide situated in the plugging direction or up to an end position remote from an insertion opening of the contact. In order to be moved out of the receptacle, in the at least one release position the driver can enter a recess of the housing. This may be achieved for example by the driver being arranged on a resilient tongue, which is pretensioned outside the at least one release position and springs into the recess in the at least one release position. Outside the at least one release position, in at least one driving position, the driver or the tongue carrying it may lie against the housing under spring pretension. According to a further advantageous design, in the at least one release position the roller contact bodies may lie both against the contact pin and against the housing of the contact. Outside the at least one release position of the slide, in the driving positions of the slide, on the other hand, the roller contact bodies may lie either only against the contact pin or only against the housing. In the case of the last design, it is ensured that the roller contact bodies do not undergo any rolling movement when the slide is moved by the contact pin by way of the driver in the driving positions. On the other hand, in the case of the first design, outside the at least one driving position the roller contact bodies roll both on the contact pin and on the housing, so that the slide moves like a roller bearing cage. Since the slide in this case moves more slowly than the contact pin, the driver is preferably moved out of the receptacle, in order not to disturb the movement of the slide dictated by the rolling movement of the roller contact bodies.

In a further design, the driver may be a latching element and for example comprise a latching projection or a latching recess. The latching element of the contact acts together with a complementary latching element of the contact pin. The latching operation preferably takes place automatically in this case, as a result of the different speeds of movement of the slide and the contact pin when the roller contact bodies roll both on the housing and on the contact pin. As a result of the higher speed of the contact pin, its complementary latching element overtakes the latching element on the slide and latches automatically.

It may be provided that the roller contact bodies are kept at a further distance from one another on the opposing sides transversely in relation to the plugging direction in an initial position of the slide, in which it is located in an end position of its movement that is situated in the direction of the insertion opening of the receptacle, than in a position of the slide in which it has moved out of the initial position in the direction of the receptacle. In the case of this design, it is ensured that at the beginning of the plugging operation no rolling movement has yet taken place. In particular, the roller contact bodies may in this case be kept at a distance from the contact pin in the initial position of the slide, when the contact pin has not yet been fully inserted into the contact. Such a distancing can be achieved if for example the slide comprises arm- or tongue- shaped regions which are elastically deflectable transversely in relation to the plugging direction and in which the roller contact bodies are located. The regions may in particular be designed such that they spring away from one another or have been sprung away from one another in the insertion opening.

In a further advantageous design, the receptacle may widen against the plugging direction towards the insertion opening, to form at least one flared run-in. In particular, the housing may widen against the plugging direction. The roller contact bodies may be moved, in particular pressed, against the flared run-in by the slide, for example as a result of the shaping of the arm- or tongue-shaped regions holding them. Consequently, the roller contact bodies have been moved away from the contact pin in the region of the flared run-in. At the beginning of the movement of the slide, when it moves out of its end position situated at the insertion opening of the receptacle, the roller contact bodies may roll exclusively on the flared run-in. Groove-shaped raceways for the roller contact bodies may be provided in the region of the flared run-in. The region in which the roller contact bodies roll exclusively on the flared run-in may coincide with the region of the driving positions of the slide in which the driver extends into the receptacle.

The movement of the slide may be divided into two portions, the first portion extending away from the initial position of the slide situated towards the insertion opening of the receptacle and the second portion extending up to the end position remote from the insertion opening. In the first portion, the slide moves at the same speed as the contact pin and is preferably moved exclusively by the contact pin. This first portion is made up in particular of the driving positions. In the second portion, the slide moves more slowly than the contact pin and is preferably moved exclusively by the roller contact bodies. As described above, this is achieved for example by the roller contact bodies only rolling on either the housing or the contact pin in the first portion, rolling both on the contact pin and on the housing in the second region. This measure allows the travel of the slide during the insertion of the contact pin to be reduced, so that a compact form of construction is achieved, which can in particular also maintain standard dimensions of existing contacts and contact pins. The second portion is preferably made up of the release positions.

According to a further advantageous design, the roller contact bodies are arranged rotatably, but translationally immovably along the insertion direction, in a housing surrounding the receptacle. In the case of such a design, a roller bearing cage that is preferably immovable in the plugging direction is present. In particular, the roller contact bodies are kept at a distance from the housing on the side that is facing away from the receptacle or the contact surface. Here, too, the housing may be produced from a conductive material.

In order to produce the contact force and press the roller contact bodies against the contact pin, at least one pressing spring may be provided, which acts on at least one roller contact body and is located between the at least one roller body on one side and the housing.

The housing may be connected in a material-bonding manner to a fastening portion for the attachment of a conductor. If the pressing springs and/or roller bearing cage are held stationarily in the housing, they may be connected in a material-bonding manner to a fastening portion instead of the housing or in addition to the housing. The fastening portion may be designed as a crimping portion for securely crimping a conductor, or for securely soldering a conductor and also for the attachment of the contact in a housing of a larger plug. In order to press the roller contact bodies against the contact pin when the contact pin and the contact are plugged together, the roller contact bodies may be held deflectably between a clearance of the housing and a clearance of the pressing spring transversely in relation to the plugging direction against the action of the pressing spring. In a further design, the housing itself may form the roller bearing cage or part of the roller bearing cage. For this purpose, the housing may comprise an inner-lying inner part, accommodating at least a portion of the roller contact bodies, and an outer-lying outer part. The inner part and the outer part may be connected to one another in a material- bonding manner, in particular monolithically, by at least one bent and/or folded connecting portion. The at least one pressing spring may be located between the inner part and the outer part, and thus be well protected. The connecting portion may lie at the opening of the receptacle and at the same time form a widening run-in for the receptacle, which makes the insertion of the contact pin easier.

For the assembly of the roller contact bodies, insertion openings through which the roller bodies fit may be present on the outer part and/or on the pressing spring. In order to be able to insert the roller contact bodies through the pressing spring, and at the same time hold them by the pressing spring, the insertion openings of the pressing spring and of the outer part can be brought into line with one another, and preferably also into line with a holding opening in the inner part, by displacing the pressing spring with respect to the outer part. In a number of displacing positions between the pressing spring and the housing that are kept at a distance from one another along the plugging direction, different insertion openings of the outer part can be brought into line with the insertion openings of the pressing spring, so that in particular the pressing spring has to have fewer insertion openings than the outer part. The outer part may have an insertion opening for each holding opening of the roller bearing cage or inner part.

After the assembly of the roller contact bodies, the pressing spring may be latched on the housing. In the latching position, the insertion openings of the pressing spring are not in line with the insertion openings of the outer part or with the holding openings of the inner part.

The pressing spring is preferably produced from a plastic, in order to create as little friction as possible with the roller contact bodies.

The invention is explained by way of example below on the basis of exemplary embodiments with reference to the accompanying drawings. For elements that correspond to one another with regard to function and/or construction, the same reference signs are always used in the accompanying drawings. For the sake of brevity, only the differences between the exemplary embodiments are discussed, unless mentioned otherwise.

Subject to the statements made above, the various features in the various exemplary embodiments can be combined with one another in any way desired. In particular, a feature of one exemplary embodiment may be omitted if the technical effect of this feature is not important in the case of a specific application. Conversely, a further feature, for example of another exemplary embodiment, may be added to an exemplary embodiment if the technical effect associated with this feature is important in the case of a specific application. In the drawings:

Figure 1 shows a schematic perspective representation of an electric contact

according to the invention;

Figure 2 shows a schematic perspective representation of the contact from Figure 1 with a complementary contact pin;

Figure 3 shows a detail of the electric contact from Figure 1 corresponding to viewing direction III of Figure 1 ;

Figure 4 shows a schematic representation of a section through the electric contact of

Figure 1 with an inserted contact pin corresponding to viewing direction IV of Figure 1 ;

Figure 5 shows a schematic representation of a first position during the insertion of a contact pin into an electric contact according to the invention;

Figure 6 shows a schematic representation of a second position during the insertion of a contact pin into an electric contact according to the invention;

Figure 7 shows a schematic representation of a third position during the insertion of a contact pin into an electric contact according to the invention; Figure 8 shows a schematic representation of a fourth position during the insertion of a contact pin into an electric contact according to the invention;

Figure 9 shows a schematic representation of view IX of Figure 8; Figure 10 shows a schematic sectional representation of a further exemplary

embodiment of a contact according to the invention with a contact pin in a first position;

Figure 1 1 shows a schematic representation of view XI of Figure 10;

Figure 12 shows a schematic representation of the exemplary embodiment of Figure 10 in a further position; Figure 13 shows a schematic representation of view XIII of Figure 12;

Figure 14 shows a schematic sectional representation of the exemplary embodiment of

Figure 10 in a further position;

Figure 15 shows a schematic representation of view XV of Figure 14;

Figure 16 shows a schematic perspective representation of a slide of a contact

according to the invention;

Figure 17 shows a schematic perspective representation of a further exemplary

embodiment of a contact according to the invention;

Figure 18 shows a schematic sectional representation along line XVIII-XVIII of Figure

17;

Figure 19 shows a schematic sectional representation along line XIX-XIX of Figure 17;

Figure 20 to Figure 27 show schematic representations of successive assembly steps during the assembly of the exemplary embodiment of Figure 17.

First, the construction and function of an exemplary embodiment of an electric contact 1 according to the invention are explained. The electric contact 1 comprises a housing 2, which encloses a receptacle 4. The receptacle 4 opens at least against a plugging direction 6. In the plugging direction 6, a complementary contact 8, for example in the form of a contact pin, is inserted into the receptacle 4. The complementary contact 8 may be designed as a pin contact, in particular, as shown in Figure 2, as a tab, but also as a pin (not shown). The electric contact 1 and the complementary contact 8 together form an electrical plug connection 10.

In Figure 2, the upper half of the housing 2 has been omitted, in order to allow a clear view into the housing 2. As can be seen, in the plugging direction 6 the housing 2 may be open at its front end 12a in the plugging direction and its rear end 12b in the plugging direction. In the receptacle 4 there is a slide 14. The slide 14 is designed in a sleeve- or box-shaped manner and lies coaxially in relation to the housing 2. It likewise surrounds the receptacle 4. The slide 14 is accommodated in the housing 2 displaceably forward and back along the plugging direction 6 and is open at least at its rear end 15b in the plugging direction 6, for inserting the pin contact through, preferably also at the front end 15a.

In Figures 1 and 2, the slide 14 is located in an initial position 16 at an insertion opening 18 at the rear end 12b of the housing 2. The rear end 15b of the slide lies against the insertion opening 18. Held rotatably on the slide 14 are roller contact bodies 20, on opposing sides 19a, 19b of the receptacle 4. For this purpose, the roller contact bodies 20 have been inserted in a form-fitting manner into clearances or recesses 22 of the slide 14. The slide 14 consequently forms a roller bearing cage 21 . The roller contact bodies 20 project into the receptacle 4.

Merely by way of example, the sides 19a, 19b are the flat sides of the receptacle 4. The roller contact bodies may also be arranged on the narrow sides of the receptacle 4.

The roller contact bodies 20 are produced from a conductive material, in particular a material with a conductivity of at least 30 S/m. The material of the roller contact bodies 20 preferably contains at least one metal from the series gold, silver, aluminium and copper.

The slide 14 is preferably produced from a non-conductive material, for example plastic, in particular is injection-moulded.

At the insertion opening 18 of the receptacle 4, the electric contact 1 comprises a running-in region 24, which widens against the plugging direction 6. The running-in region 24 may for example be formed by two vanes 26, which project from the sleeve- or box- shaped region 28 of the housing 2 against the plugging direction and are inclined with respect to the plugging direction 6.

The slide 14 may comprise spring tongues or arms 30, which project from a sleeve- or box-shaped portion 32 of the slide 14 against and/or in the plugging direction 6. At least one roller contact body 20 may be provided on each of the spring tongues or arms 30, at or in the vicinity of the end 34 that is facing the opening 18.

The spring tongues or arms 30 are preformed such that in the force-free state they tend to move away from one another. Consequently, the form of the spring tongues or arms 30 follows the widening running-in region 24 when the slide is displaced against the plugging direction 6 towards the rear end 12b of the housing 2. As Figure 2 shows, the contact pin 8 may be provided with at least one latching element 36, for example a latching projection or a latching recess, which is located on a narrow side 38.

If the slide 14 is displaced from the initial position 16 shown in Figure 2 at the opening 18 in the plugging direction 6 towards the front end 12a of the housing, the roller contact bodies 20 move towards one another along the running-in region 24. As soon as the roller contact bodies 20 have arrived in the sleeve- or box-shaped region 28 of the housing 2, the distance between them remains substantially constant during the further movement of the slide in the plugging direction 6. In the region 28, the roller contact bodies 20 have been pressed against the housing 2 as a result of the elastic deformation of the spring tongues or arms 30 that has then occurred, so that they roll on an inner side or surface of the housing 2. The pressing force with which the roller contact bodies 20 are pressed against the housing 2 thereby increases as the distance between the opposing roller contact bodies 20 is increasingly reduced.

The slide 14 is preferably displaceable along the plugging direction between two end positions 42, 44, which are determined by two stops 46, 48. The stops 46, 48 may be arranged on the housing and act together with a guiding element 50 on the slide. The guiding element 50 may for example be a rib 50 protruding into a groove or a slit 52 of the housing 2. The groove 52 extends in a straight line in the plugging direction 6, the stops 46 and 48 are the ends of the groove. It goes without saying that this arrangement can also be reversed, so that the groove or the slit 52 is located on the slide and the guiding element is located on the housing. The housing 2 may also comprise groove-shaped raceways 54, which extend along the plugging direction 6 and on which the roller contact bodies 20 roll. The running grooves 54 can be seen in particular in Figure 3, in which part of the housing 2 has been removed. The running grooves 54 may be formed on housing tongues 56, which slightly yield transversely in relation to the plugging direction 6. The housing tongues 56 may be connected to the housing 2 only at their two ends situated in the plugging direction or only at one end. As a result of their yielding compliance, the housing tongues 56 act as pressing springs 58, which press the roller contact bodies 20 into the receptacle 4 as soon as the housing tongues 56 are deflected. Once the contact pin 8 has been inserted into the receptacle 4 and the slide 14 has moved in the plugging direction 6 out of the rear end position 46 in the plugging direction 6, situated in the direction of the rear end 12b, the roller contact bodies 20 come to lie against the contact pin 8. In order to produce sufficiently high contact forces 60, the roller contact bodies 20 are pressed against the running grooves 54, which thereupon yield elastically. This is shown in Figure 4.

The outer surfaces of the roller contact bodies 20 that protrude into the receptacle 4 form a contact surface 61 of the contact 1 , which contacts the contact surface 62 of the complementary contact 8 in the plugged-together state (also see Figure 2). As a result of the curved surface of the roller contact bodies 20, the contact forces 60 act on a small surface area and consequently exert a great surface pressure.

The plugging operation is explained in more detail below with reference to Figures 5 to 9. Shown there is a variant in which the running grooves 54 are slit-shaped, as Figure 9 in particular shows. In the case of this design, the elastic yielding compliance is used for producing the pressing force 60 by the yielding compliance of the edges of the running groove 54. Also shown in Figures 5 to 8 is an outer housing 63, in which the housing 2 is

accommodated.

In Figure 5, the slide 14 is in the initial position 16, as it is shown in Figures 1 and 2, that is to say the rear end position 42. The roller contact bodies 20 lie in the running-in region 24 and are at a distance from one another that is greater than the thickness of the material of the contact pin in the direction of this distance. In the initial position, the roller contact bodies 20 do not touch the contact pin 8.

In Figure 5, the contact pin 8 has just been fully inserted into the slide 14, so that at its end 64 situated in the plugging direction 6 it bears against at least one driver 66 of the cage 14. Merely by way of example, Figure 5 shows two drivers 66 on the opposing sides 19a, 19b. The driver 66 protrudes into the receptacle 4 and is preferably located at the front end 15a of the slide 14. The slide 14 may be provided with bearing supports 68, which receive and centre the contact pin 8 in an exactly fitting manner on at least two opposing sides transversely in relation to the plugging direction.

If the contact pin 8 is then pushed further in the plugging direction 6, it moves the slide 14 from the initial position 16 likewise in the plugging direction 6 by way of the drivers 66. The roller contact bodies 20 can thereby roll on the housing 2, in particular the running grooves 54. The roller contact bodies 20 on the spring tongues or arms 30 thereby run towards one another along the running-in region 24 without touching the contact pin 8. Such a position 69 of the slide, referred to hereinafter as the driving position, is shown in Figure 6. In the driving position 69, the slide 14 has been moved out of the initial position in the plugging direction 6 and the roller contact bodies 20 are located at the end of the running-in region 24 that is situated in the direction of insertion 6, at the transition to the region 28 of the housing 2. The slide 14 and the contact pin 8 move at the same speed.

Shown in Figure 7 is a position 70 of the slide 14, referred to hereinafter as the release position, that lies between the end positions 42, 44 of the slide 14 and in particular before the driving position 69 in the plugging direction 6, that is to say closer to the front end 12a of the housing. The roller contact bodies 20 lie on the contact surface 62 of the contact pin 8 under the effect of the contact force 60. At the same time, the roller contact bodies 20 have been pressed into the running grooves 54, which have been elastically deflected transversely in relation to the plugging direction 6 and produce the pressing force 60. The roller contact bodies 20 then roll on the housing 2 and on the contact pin 8. The slide 14 is then no longer moved in the plugging direction 6 directly by the contact pin 8, but by the movement of the rolling roller contact bodies 20. This speed of movement of the slide 14 is lower than the speed at which the contact pin 8 is inserted into the receptacle 4. The contact pin 8 consequently overtakes the slide 14. The driver 66 has been moved out of the receptacle 4, so that the contact pin 8 can move past the driver 66. The movement of the driver 66 out of the receptacle 4 is made possible for example by a groove- or slit- shaped recess 71 , which is entered by the driver 66 from when the release position 70 of the slide 14 is reached. For this purpose, the driver 66 may be arranged on a spring tongue 72.

The position in which the drivers 66 have been moved out of the receptacle 4

corresponds in this case to the position from which the roller contact bodies 20 roll both on the contact pin 8 and on the housing 2. In this way it is ensured that the slide 14 moves continuously into the release position 70 and further into the end position 44.

Starting from the position shown in Figure 7, the contact pin 8 can then be moved further in the plugging direction 6. It is thereby centred and held by the roller contact bodies 20 and the bearing supports 68. In Figures 10 to 15, various phases of the plugging together of the electric contact 1 and the contact pin 8 are shown in a design that has been modified slightly as compared with Figures 5 to 9. For the sake of brevity, only the differences from the previous embodiment are discussed.

In the case of the embodiment of Figures 10 to 15, the driver 66 is part of a latching arrangement 74, which also comprises in particular the latching element 36 on the contact pin (also see Figure 2). It is merely by way of example that the driver 66 is arranged opposite the narrow side 38 of the contact pin 8. It may equally be arranged opposite the flat side 76 of the contact pin 8, that is to say on one of the sides 19a and 19b. The latching arrangement 74 may in particular be used in addition to the design that is shown in Figures 5 to 9.

The latching arrangement 74 engages in the initial position 16 of the slide, so that the slide 14 is moved in the plugging direction 6 by the contact pin 8 as a result of the form fit in the plugging direction 6 that is established by the latching arrangement 74. The initial position 16 is shown in Figures 10 and 1 1.

The driver 66 and the latching element 36, designed here as a projection, lie against one another, so that the movement of the contact pin 8 is transferred to the slide 14. The roller contact bodies 20 are kept at a distance from the contact pin 8. Instead of the two projections lying against one another, as they are shown in Figure 1 1 , it goes without saying that on the slide or contact pin there may also be just one projection, which engages in a corresponding recess on the other element, respectively.

In the course of the movement in the plugging direction 6, the roller bodies 20 come to lie both against the contact pin 8 and against the housing 2. This is the case whenever the roller contact bodies 20 have reached the end of the running-in region 24 situated in the plugging direction 6. At this position, the contact pin 8 begins to overtake the slide 14, since the speed of the slide 14 is then determined by the translational speed of the roller contact bodies 20 in the plugging direction 6. This translational speed is lower than the speed of the slide 14 in the plugging direction.

As shown in Figures 14 and 15, as a result of the higher speed of the contact pin 8 the latching arrangement 74 latches of its own accord, preferably before or in the end position 44 of the slide 14. The latching arrangement 74 secures the contact pin 8 in the receptacle 4. A play between the pin contact and the slide in the plugging direction 6 that is made possible by the latching arrangement 74 may be used for the purpose of compensating for relative movements between the plug 1 and the contact pin 8, in particular in environments that are subjected to vibrational loading.

In Figure 1 , the slide 14 is provided with an individual row of roller contact bodies 20 extending transversely in relation to the plugging direction 6. It goes without saying that more than one row of roller contact bodies 20 and/or roller contact bodies arranged offset in relation to one another can also be used. Figure 16 shows a modified slide, which for example can be used instead of the slide 14 of Figure 1. In the case of this design, the spring tongues or arms 30 at the end of which the roller contact bodies 20 are held are of different lengths. The roller contact bodies 20 consequently lie on the contact pin 8 at a distance from one another in the plugging direction 6, which leads to better supporting of tilting moments that act on the contact pin 8.

The electric contact 1 does not have to be provided with a movable slide 14, as explained on the basis of the following exemplary embodiments, in particular initially on the basis of Figures 17 to 19.

The electric contact 1 of Figures 17 to 19 likewise has rotationally mounted roller contact bodies 20, which lie opposite one another with respect to the receptacle 4 on the sides 19a, 19b. The housing 2 surrounds a roller bearing cage 21 , which may be formed as one part or, as shown, as two parts. An inner part 78 of the roller bearing cage 21 is facing the receptacle 4. An outer part 80 of the roller bearing cage 21 is arranged between the housing 2 and the inner part 78. The roller contact bodies 20 are arranged between the inner part 78 and the outer part 80. The outer part 80 serves as a pressing spring 58. In the same way as the running grooves 54 of the previous exemplary embodiments, the pressing spring 58 is elastically deflectable transversely in relation to the plugging direction 6, so that the contact force 60 is produced when the roller contact bodies 20 are pressed by the inserted contact pin 8 out of the receptacle 4 against the action of the pressing spring 58.

The inner part 78 may be connected to the housing 2 in a material-bonding manner, in particular monolithically, by way of a bent and/or folded connecting portion 82. The connecting portion 82 may form a sloping running-in region 24 that widens against the plugging direction 6.

A fastening portion 84 of the electric contact 1 may serve for the fastening of a conductor 85 or for the fastening of the electric contact in a plugging contact. In particular, the electric contact 1 may be designed as a crimping contact 86, in which the fastening portion 84 forms a crimping portion for crimping a conductor. The fastening portion may be formed with the housing 2 in a material-bonding manner, in particular monolithically, and/or, as shown, with the outer part 80.

The roller contact bodies 20 are held in a form-fitting and rotatable manner between the inner part 78 and the outer part 80. The greatest cross section 88 lies in this case between the inner part 78 and the outer part 80. The roller contact bodies 20 rest in recesses 90 in the inner part 78 and outer part 80, which are in line with one another transversely in relation to the plugging direction 6.

The housing 2 may be accommodated in an outer housing 63 (not shown).

During the insertion of the contact pin 8 in the plugging direction 6, the roller contact bodies 20 roll on its contact surface 62 and thus reduce the plugging forces necessary for the plugging. The roller contact bodies 20 thereby remain stationary, held by the roller bearing cage 21 , and only rotate in the clearances 90.

The assembly of the contact 1 of Figures 17 to 19 is explained below with reference to Figures 20 to 27.

In a first step, according to Figure 20, the housing 2 is pushed over the inner part 78 in the plugging direction 6. The housing 2 has insertion openings 90, the number and position of which corresponds to the number and position of the receptacles 90 of the inner part 78. On the inner part 78 there are a number of insertion openings 90 that is less than the number of receptacles 90 or the number of roller contact bodies 20. In order that all of the roller contact bodies 20 can nevertheless be arranged between the pressing spring 58 and the inner part 78, for assembly purposes the pressing spring 58 is displaceable in the housing 2 along the plugging direction 6 like a slide 14. In various displacing positions, different insertion openings 90 in the housing 2 are in line with the insertion openings 90 in the pressing spring 58, so that the roller contact bodies 20 can be inserted through the housing 2 and the pressing spring 58 into the recesses 22 of the inner part 78. Subsequently, the pressing spring 58 is once again displaced along the plugging direction 6, in order to insert roller contact bodies 20 into other receptacles 22, which are then in line with the insertion openings 88 in the housing 2 and the pressing spring 58. The already assembled roller contact bodies 20 thereby roll in the longitudinal grooves 54, which adjoin the insertion opening 90 of the pressing spring 58. This is explained in more detail below.

In Figure 21 , the housing 2 has been pushed in the plugging direction 6 over the pressing spring 58, so that the two insertion openings 90 are in line with one another. As shown in Figure 22, the roller contact bodies 20 are then inserted through the two in-line insertion openings 90, until they are accommodated in the recesses 22 in line with the insertion openings 88, as Figure 23 shows.

In order to load the still free receptacles 22 with roller contact bodies 20, the pressing spring 58 and the housing 2 are once again moved in relation to one another along the plugging direction 6, until still free recesses 22 of the inner part 78 are in line with the insertion openings 88 in the pressing spring 58 and in the housing 2. As a result of the displacement of the pressing spring 58 in the housing 2, the already inserted roller contact bodies 20 are then held between the pressing spring 58 and the inner part 78 since they are supported on the running groove 54. The running groove 54 has for this purpose a clear width that is smaller than the diameter of the roller contact bodies 20.

When the insertion openings 88 are in line with the still free recesses 22 at the new displacing position, roller contact bodies 20 are once again inserted through the insertion openings 90, as has already taken place in the previous step for the previous displacing position. Thus, all of the recesses 22 can be loaded with roller contact bodies 20 one after the other. Subsequently, the pressing spring 58 can be arrested in the housing 2 by a latching arrangement 74 in a displacing position in which the insertion openings 88 of the housing 2 are no longer in line with the insertion openings 90 of the pressing spring 58 and all of the roller contact bodies 20 lie in the running grooves 54 of the pressing spring 58. List of designations

1 electric contact

2 housing

4 receptacle

6 plugging direction

8 contact pin

10 electrical plugging connection

12a front end of the housing

12b rear end of the housing

14 slide

15a front end of the slide

15b rear end of the slide

16 initial position

18 insertion opening

19a, 19b opposing sides of the receptacle

20 roller contact body

21 roller bearing cage

22 recess for roller contact body

24 running-in region

26 vane

28 sleeve- or box-shaped region of the housing

30 spring tongues or arms

32 sleeve- or box-shaped portion of the slide

34 end of the spring tongues or arms facing against the plugging direction

36 latching element

38 narrow side

40 inner side/surface of the housing

42 rear end position of the slide

44 front end position of the slide

46 rear stop

48 front stop

50 guiding element

52 groove or slit

54 running groove

56 housing tongue

58 pressing spring 60 contact force

61 contact surface of the contact

62 contact surface of the complementary contact

63 outer housing

64 front end of the slide

66 driver

68 bearing support

69 driving position

70 release position

71 recess

72 spring tongue

74 latching arrangement

76 flat side

78 inner part

80 outer part

82 connecting portion

84 fastening portion

85 conductor

86 crimping contact

88 greatest diameter of the roller contact bodies

90 insertion opening