GB2398680A

GB2398680A - Spring contact ring

Info

Publication number: GB2398680A
Application number: GB0401220A
Authority: GB
Inventors: Anton Lammle
Original assignee: Multi Holding AG
Current assignee: Multi Holding AG
Priority date: 2003-02-21
Filing date: 2004-01-20
Publication date: 2004-08-25
Anticipated expiration: 2024-01-20
Also published as: GB2398680B; GB0401220D0; DE102004002921A1

Abstract

A spring contact element is made from a strip 10 (figures 1, 2) having two or more contacts 13 arranged one behind another and closing means 14, 15, 18, 19, for example latching elements: the strip is bent to form a closed ring or band with the closing means engaged together. The latches may be formed of complementary hooks 14, 15 and keepers 18, 19. The band may be engaged in a recess in a contact pin (figure 8) or in a socket contact (not shown). The band may alternatively be formed from a backing strip 31 (figure 6) on which contacts 34 are mounted on behind another: the backing strip is formed with a complementary latch 38 and keeper 36. The material of the backing strip is selected particularly for resilience and that of the contacts for electrical conductivity.

Description

DESCRIPTION

CONTACT ELEMENT IN THE FORM OF A STRIP, METHOD FOR ITS

PRODUCTION AND APPLICATION OF SUCH A CONTACT ELEMENT

TECHNICAL BACKGROUND

The present invention relates to the field of

electrical contact-. It relates to a contact element in the form of a strip according to the preamble of Claim 1.

Such a contact element is disclosed, for example, in EP-A1-1 119 077 by the applicant.

PRIOR ART

In order to provide contact in the case of releasable electrical connections for high currents, such as, for example, in the case of screwconnected busbars or high-current plug connectors, contact elements which are in the form of strips are often used and lie between the adjacent, parallel contact faces of the connection and provide the electrical contact between the spaced-apart contact faces by means of a large number of sprung individual contacts with high load capacities.

A particularly simple, integral form of such contact elements is disclosed, for example, in US-A-3,453,587 or US-A-4,083,622. With these known integral contact elements, a large number of contact lamellae, which run transversely between two parallel peripheral webs and which are arranged spaced evenly apart, one behind the other in the longitudinal direction of the strip, are produced from spring sheet metal in the form of a strip by means of a combined stamping and bending process.

The contact lamellae, which are cut such that they are bulbous, are twisted out of the strip plane by torsion - 2 - of the joints between the lamellae and the peripheral webs and can bridge a specific spacing or a tolerance between the contact faces in a sprung manner. Here, the convex edges of the lamellae are in contact with the faces. The spring-loading is provided in the manner of a torsion spring.

With the integral contact elements mentioned above, by selecting the basic strip material, both the spring properties and the electrical and contact-making properties of the finished contact element are determined at the same time, so that a compromise often has to be made here. It has therefore already been proposed to use, instead of integral contact elements, two-part contact elements, in which separate contact bodies in the form of plates and having optimized electrical properties are fixed, as contact lamellae, to a mounting strip having optimized spring properties.

Examples of such two-part contact elements are described in CH-A5-650 108 or US-A-4,725,251. The contact bodies in the form of plates are arranged on the mounting strip spaced apart from one another, which ensures that the contact bodies do not obstruct one another when rotated back into the strip plane. The maximum spacing between the contact faces which can be bridged by the contact element in this case depends on the dimensions of the contact bodies in the longitudinal direction of the strip: the greater the dimensions of the contact bodies in the longitudinal direction, the greater the maximum bridgeable spacing also is. On the other hand, the spacing of the contact bodies from one another also increases as they increase in size, so that the number of contact bodies and thus the contact with the contact faces per unit length of the contact element is reduced in size.

In order to eliminate this dependence of the contact density and the maximum bridgeable spacing, EP-Al-1 119 077, mentioned initially, proposes a two part contact element in which sloping, V-shaped contact bridges are fixed, as contact bodies, to a mounting -strip in a sprung manner and such that they are interleaved. The interleaving makes it possible, with a constant contact density, to increase the maximum bridgeable spacing by the limbs of the bridges being extended.

The above-described types of contact elements in the form of strips may all be used when flat between two planar contact faces (see, for example, Fig. 5 in US-A-4, 083,622 and Fig. 5 in EP-Al-1 119 077). Bent to form a circular ring, they may also be used, however, in a concentric plug connection in the form of a circular cylinder, as is shown in Figs 6 and 7 in EP-Al-1 119 077 or in Figs 1 and 2 in US-A-4, 083,622.

The contact element, which is bent to form an open ring, may in this case be arranged either in an annular groove on the outer circumference of the plug (Fig. 6 in EP-Al-1 119 077) or else in an annular groove on the inner circumference of the associated socket (Fig. 7 in EP-Al-1 119 077).

The annular groove, in which the contact element in the form of a strip which is bent to form an open ring is arranged, serves, on the one hand, to entirely accommodate the contact element when the contact faces lie directly on top of one another. This reliably avoids damage to the contact element. The annular groove serves, on the other hand, to prevent the contact element from being axially displaced when the plug is inserted into the socket. Finally, the annular groove in many cases serves to secure the annular contact element against falling off or out. In order to ensure that the contact element is secured in this manner, the side walls of the annular groove are provided with undercuts, which either have a rectangular (T-groove) or a V-shaped cross-sectional profile. In the case of V-shaped undercuts, a dovetail - 4 - profile results for the annular groove, as can be seen in Fig. 7 in EP-Al- 1 119 077 or in Fig. 19 in CH-A5-650 108. The edges of the contact element are at the same time provided with lugs, tabs or projections which are arranged distributed along the length, protrude laterally, engage in the undercuts and thus prevent the contact element from falling or sliding out of the annular groove. In order that the contact element can be inserted into such a T-groove or dovetail groove at all, lateral cutouts, through which the undercut can be accessed from above, must be provided at specific points on the annular groove. One end of the contact element must then be pushed through the cutouts into the groove during assembly, and when in the groove, the contact element, guided in the undercuts by its lugs, tabs or projections, then follows the circumference and forms an open ring.

This way of securing the contact element has various disadvantages: - It is complicated and time-consuming and thus expensive to work a recess into the plug or the socket for the purpose of providing the T- groove or dovetail groove.

- An additional working step is required to provide the cutouts for threading in the contact element.

- The complicated profile of the undercuts with the additional corners leads to increased depositions in the galvanic treatment following the mechanical processing (so-called bone-forming). These depositions may make assembly of the contact element more difficult.

- The assembly of the contact element by threading it through the cutout into the annular groove - in particular on the inner circumference of the socket - is difficult and time-consuming.

- One end of the contact element may, under unfavourable circumstances, protrude outwards through the cutout again and be damaged in a subsequent insertion step.

However, ways of securing the contact element in the annular groove which just use a straight recess have been disclosed. Such a way of securing the contact element consists in incorporating additional holding strips on the two edges of the annular groove. The holding strips, which are offered by the applicant under the designation "LAMFIX", are fixed in a clamping manner in the annular groove such that they are bent in the form of a ring. They bear against the side walls of the groove and project with a holding strip, which is bent back inwards at a right angle, into the annular groove. The holding strips which are bent back inwards act as an undercut into which the contact element can then be threaded.

Another way of securing the contact element consists in pushing snap rings, which fix the contact element in the annular groove, on both sides over the edge regions of the contact element which is bent in the annular groove to form a ring.

A further way of securing contact elements arranged on the inner circumference of the socket comprises an additional connecting piece into which the two ends of the contact element are pushed and are held from opposing sides once the ring has formed. Such a connecting piece is offered by the applicant under the designation "H-FIXN.

These ways of securing the contact element likewise have various disadvantages: - Additional parts (holding strips, snap rings, connecting pieces etc.) are required for securing purposes and have to be produced and kept in store.

- Assembly is made more complex by the use of the additional parts. - 6 -

- Special auxiliary tools are required for assembly.

- Additional space is required in the annular groove when using holding strips.

- Snap rings can only be used for securing purposes when the edge regions of the contact elements lie on the base of the annular groove.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a contact element in the form of a strip for use in the form of a ring, which contact element can be produced easily, can be secured at the point of attachment in the ring shape without additionally [sic] parts, requires a small amount of space and can be assembled quickly and easily, as well as to specify a method for its production and an application.

The object is achieved by all of the features of Claims 1, 15 and 19. The essence of the invention consists in closing means, which can be used to connect the ends of the contact element, which is bent in the form of a ring, to one another so as to form a closed ring, being provided on the contact element. Connecting the ends forms a closed ring which is fixed and secured at the point of attachment by virtue of its closed form. Since the closing means are arranged on the contact element itself, additional parts are not required for securing purposes. At the same time, the contact element can be assembled more easily and more quickly.

A first preferred refinement of the invention is characterized in that the closing means are arranged at both ends of the contact element, and in that the closing means can be connected to one another in a latching manner. The arrangement of the closing means at the ends of the contact element means that the design of the contact element remains largely unchanged. The latching connection considerably simplifies assembly.

In accordance with a preferred development of the refinement, the closing means have, arranged at one end of the contact element, connection elements which can be inserted in a latching manner into accommodating devices, arranged at the other end of the contact element, in the circumferential direction of the ring, and the connection elements are in the form of latching hooks extending in the longitudinal direction of the contact element. In particular, the contact element comprises a mounting strip, which extends in the longitudinal direction and to which the contact bodies are fixed, and the connection elements and accommodating devices are integrally formed at the ends of the mounting strip. This has the particular advantage that the closing means can be formed at the ends of the contact element without the need for additional material to be used. Since the contact elements are usually produced in the form of strips in one continuous process, a section of suitable length can be cut off from the strip, and the closing means are then formed at the ends of this section.

The mounting strip preferably comprises two parallel peripheral webs, between which the contact bodies are arranged. The connection elements and accommodating devices are then integrally formed at the ends of the peripheral webs.

The contact bodies are then either in the form of lamellae running between the peripheral webs, and the peripheral webs and lamellae are produced by a stamping process from a common sheet metal strip.

Or the contact bodies are in the form of separate contact platelets which are fixed to transverse webs running between the peripheral webs. - 8 -

Alternatively, however, the mounting strip may also comprise a central web, from which spring arms, to which the contact bodies are fixed, branch off laterally. The connection elements and accommodating devices are then integrally formed at the ends of the central web and the contact bodies are in the form of separate contact bridges which are fixed to the ends of the spring arms.

A preferred development is characterized in that the accommodating devices comprise two latching lugs which are bent out in the transverse direction from the plane of the mounting strip in the opposite direction, and in that each latching lug has an associated connection element which latches in behind the latching lug in the opposite direction.

Another preferred development is characterized in that the mounting strip is made of spring sheet metal, in particular of a Cu or Ni alloy or spring steel.

In accordance with a second preferred refinement, the closing means are designed such that the spacing between the ends of the contact element in the closed ring has a prescribed amount of play, preferably in the region of two or more millimetres. This makes it possible to compensate for the change in diameter of the contact element, which is bent to form a ring, which results when the contact element is compressed in a resilient manner between the adjacent contact faces perpendicular to the strip plane.

The method according to the invention for the production of a contact element according to the invention, which comprises a mounting strip having at least one first web running in the longitudinal direction and two or more second webs running transversely to the first web, is characterized in that - 9 - the closing means are formed from sections of the at least one first web and the second webs of the mounting strip. This advantageously ensures that the closing means can be formed directly from the mounting strip without additional use of material, as is required for the construction of the contact element and is produced in a continuous stamping process.

A preferred refinement of the method according to the invention is characterized in that the closing means have, arranged at one end of the contact element, connection elements, which can be inserted in a latching manner into accommodating devices, arranged at the other end of the contact element, in the circumferential direction of the ring, in that the connection elements are in the form of latching hooks extending in the longitudinal direction of the contact element, in that the accommodating devices comprise two latching lugs bent out in the transverse direction from the plane of the mounting strip in the opposite direction, in that each latching lug has an associated latching hook which latches in behind the latching lug in the opposite direction, in that the latching hooks are each formed from a section of the first web and sections of a second web which branch off from said first web, and in that the latching lugs are formed from web sections of a second web. In particular, the latching lugs are formed from web sections of a second web by the web sections being bent through approximately 180 .

Furthermore, in order to achieve a prescribed amount of play for the spacing between the ends of the contact element in the closed ring, at least one of the second webs is preferably removed from the mounting strip.

The application according to the invention of the [lacuna] in a plug connection, which comprises a hollow-cylindrical socket and a cylindrical plug which - 10 can be inserted into the socket, is characterized in that the contact element is arranged as a closed ring in an annular groove on the inner circumference of the socket and/or on the outer circumference of the plug.

The annular groove is in this case preferably designed as a straight recess.

BRIEF EXPLANATION OF THE FIGURES

The invention is explained in more detail below with reference to exemplary embodiments in connection with the drawing, in which: Fig. 1 shows two suLfigures, in cross section (Fig. la) and in plan view (Fig. lb), of a first preferred exemplary embodiment of a(n) (integral) contact element according to the invention, only the end regions of the contact element, which is bent to form a ring and is not yet closed, being shown; Fig. 2 shows the plan view of the contact element from Fig. 1 when it is closed in the form of a ring; Fig. 3 shows the plan view of a second preferred exemplary embodiment of a (two-part) contact element according to the invention when it is not bent; Fig. 4 shows two suLfigures of the side view (Fig. 4a) and the plan view (Fig. 4b) of the two-part contact element from Fig. 3, only the end regions of the contact element, which is bent to form a ring and is not yet closed, being shown; Fig. 5 shows the plan view of the contact element from Fig. 4 when it is closed in the form of a ring; - 11 - Fig. 6 shows and [sic] the plan view of a third preferred exemplary embodiment of a (two-part) contact element according to the invention, only the end regions of the contact element, which is bent to form a ring and is not yet closed, being shown; Fig. 7 shows the plan view of the contact element from Fig. 6 when it is closed in the form of a ring; Fig. 8 shows a perspective, partially sectioned illustration of the attachment of a contact element according to Fig. 6 on the plug of a high-current plug connection; Fig. 9 shows a plurality of subfigures (9a-d) of the plan view of various steps in the production of the accommodating devices and/or latching lugs at one end of a contact element according to Fig. 3; Fig. 10 shows a plurality of subfigures (lea, b) of the plan view of various steps in the production of the latching hooks at the other end of the contact element according to Fig. 3; Fig. 11 shows the plan view of the ready-produced contact element from Figs 9, 10, only the end regions of the contact element, which is bent to form a ring and is not yet closed, being shown; and Fig. 12 shows the contact element from Fig. 11 when it is closed in the form of a ring.

WAYS OF IMPLEMENTING THE INVENTION

Fig. 1 shows two subfigures in cross section (Fig. la) and in plan view (Fig. lb) of a first preferred - 12 exemplary embodiment of a(n) (integral) contact element according to the invention, only the end regions of the contact element, which is bent to form a ring and is not yet closed, being shown. The integral contact element 10 in the form of a strip is produced by a combined stamping and bending process from a spring sheet metal strip which is made of, for example, a suitable Cu or Ni alloy. It comprises two parallel peripheral webs 11 and 12, between which a large number of evenly spaced lamellae 13 extend transversely. The lamellae 13 have a bulbous peripheral contour and, as can be seen in Fig. la, are twisted out of the strip plane. The connecting sections twisted here between the lamellae 13 and the peripheral webs 11, 12 form torsion springs which provide the contact element 10 with spring properties in the direction perpendicular to the strip plane. Such contact elements based on the known principle of contact lamellae having ends cut off straight have long been offered by the applicant under the trade name Multilam LAI.

According to the invention, the ends of such a contact element are in this case modified such that closing means 14, ..., 19, which can be used to close the contact element 10 which is bent to form a ring, are produced on the contact element 10. The modification takes place in this case - as is explained in more detail at a later point in connection with Figures 9 to 12 - such that the closing means 14, ..., 19 are formed from elements of the unmodified contact element which are provided anyway. This has the advantage that the production of the contact elements, in which the strips are continuously produced and then cut to length to match the respective application, does not need to be changed.

The closing means 14, ..., 19 of the contact element 10 comprise two parallel latching hooks 14, 15, extending in the longitudinal direction, at one end of the - 13 contact element 10, and two accommodating devices 16, 17, each having a latching lug 18, 19 and matching the latching hooks 14, 15, at the other end of the contact element 10. The latching hooks 14, 15 and accommodating devices 16, 17 form an extension Of the respective peripheral webs 11, 12. The latching lugs 18, 19 are short, remaining sections of an otherwise cut-away lamella. The latching lugs 18, 19 are bent directly at the attachment to the peripheral web 11, 12 from the inside out through 180 and have a spacing from the peripheral web 11, 12 lying therebeneath which is slightly greater than the thickness of the strip material used for the contact element 10. Peripheral webs 11, 12 and latching lugs 18, 19 together form - as can be seen in Fig. la as well in each case a guide for accommodating the latching hook 14, 15 lying opposite. If the latching hooks 14, 15 of one end of the contact element 10 are pushed into the accommodating devices 16, 17 in the direction of the arrow shown in Fig. lb, the latching hooks 14, 15 are bent slightly outwards in a resilient, sprung manner in order then to latch in, with their latching step, behind the latching lugs 18, 19 such that they can spring back (Fig. 2).

In order to form the latching hooks 14, 15, at least two of the lamellae 13 have largely (except for the latching steps) been removed at this end of the contact element 10. This results in a play x of, for example, two or more millimetres remaining for the spacing of the two ends from one another once the latching hooks have latched in (Fig. 2). Associated with the play x in the spacing between the ends is a variation range in the diameter of the closed contact element ring. This variation range is necessary in order to be able to match the ring to its fit when the lamellae 13 are pressed increasingly flat, when they are subjected to a load. If the contact element ring sits on the plug of a plug connection (see Fig. 8), when the lamellae 13 are - 14 pressed flat the pitch circle is reduced in size, i.e. the ends of the contact element 10 move towards one another. If the contact element ring sits in the socket of a plug connection (comparable to Fig. 7 in EP-A1-1 119 077), when the lamellae 13 are pressed flat the pitch circle is increased in size, i.e. the ends of the contact element 10 move away from one another. This behaviour must be taken into account when determining the length of the contact element 10 for the respective application.

Figs 3 to 5 show a second preferred exemplary embodiment of a contact element according to the invention. The contact element 20 is in two parts, i.e. it has a (highly sprung) mounting strip (for example made of spring steel) to which individual contact bodies are fixed, arranged in a row, in the form of contact platelets 23. The mounting strip comprises two parallel peripheral webs 21, 22, between which a large number of evenly spaced transverse webs (48, 49 in Fig. lea) run transversely. The highly electrically conductive contact platelets 23 are each fixed to the transverse webs. Such contact elements having straight- cut ends have long been offered by the applicant under the trade name Multilam LA-CU.

In this case too, latching hooks 24, 25 are formed at one end of the contact element 20, as an extension to the lateral webs 21, 22, and accommodating devices 26, 27 having corresponding latching lugs 28, 29 are formed at the other end. For this purpose, using the unmodified contact element as a basis, the two latter contact platelets 23 are omitted and the associated transverse webs are cut away until only the sections required as latching lugs and latching steps remain. If the contact element 20 is bent to form a ring (Fig. 4) and if the ends are then connected to one another in the direction of the arrow by inserting the latching - 15 hooks 24, 25 (fig. 5), in this case too the required play x for the spacing between the ends is ensured.

A third preferred exemplary embodiment of a contact element according to the invention is shown in Figs 6 and 7. The contact element 30 is a twopart contact element and comprises a (highly sprung) mounting strip 39 on which individual, sloping, V-shaped (highly electrically conductive) contact bridges 34 are arranged one behind the other. The electrical load which can be applied to each contact bridge is, for example, 50 A. The mounting strip 39 comprises a central web 31 which runs in the longitudinal direction and from which individual pairs of spring arms 32, 33 branch off transversely and symmetrically to both sides. Each pair of spring arms 32, 33 has an associated contact bridge 34. The free ends of the contact bridge 34 are each fixed to the free ends of the spring arms 32, 33. The contact bridges 34 are interleaved. This makes it possible for the contact element 30 to bridge greater spacings between the adjacent contact faces whilst maintaining a constant contact density. Such contact elements having straight- cut ends have long been offered by the applicant under the trade name Multilam LA-CUT and are typically used on plugs or in sockets having a diameter greater than mm.

In this case, the closing means for closing the contact element ring are formed from parts of the central web 31 and the spring arms 32, 33. As an extension of the central web 31, a twin latching hook 37, which has a separating slot 38, is formed at one end of the contact element 30. Opposite this, an accommodating device 35 having two latching lugs 36 is arranged at the other end of.the contact element 30 as an extension of the central web 31. The latching lugs 36 are formed from remaining web sections of a cut-away pair of spring arms which are bent inwards through 180 . In order to - 16 form the twin latching hook 37, two pairs of spring arms are entirely cut away. Of a third pair, only the sections required for the latching steps of the latching hook 37 remain. In order to close the still open contact element ring (Fig. 6), the twin latching hook 37 is inserted into the accommodating device 35 in the direction of the arrow until the latching hook 37 latches in behind the latching lug 36. The spring- loading of the latching hook 37 is ensured by the slot 38.

The production of the contact element 20 from Figs 3-5 is shown by way of example in Figs 9 and 10. The unmodified conventional contact element 20 of the strip is firstly cut off straight, along a cutting line 44 (Fig. 9a). Then, the last contact platelet 23, located at the end, is removed (Fig. 9b). A centre piece is then cut out from the transverse web 45, which has become free by removing the contact platelet, so that two web sections 46, 47 lying opposite one another remain (Fig. 9c). The web sections 46, 47 are finally bent outwards through 180 and then form the latching lugs 28, 29 of an accommodating device 26, 27.

Taking into account the required length of the contact element 20, a further straight cut along a section line 44' forms a second end of the contact element (Fig. lea). The two last contact platelets 23 are removed at the second end, so that two transverse webs 48, 49 become free. The inner transverse web 48 of the two transverse webs 48, 49 is removed completely (cut or stamped away). All that remains of the outer transverse web 49 is that which forms the latching edges of two latching hooks 24, 25 (Fig. lob). In addition, a slope is provided on the latching hooks 24, 25 which makes it easier to insert the latching hooks 24, 25 into the accommodating devices 26, 27. The contact element 20 modified in this way can then be bent to form an open ring (Fig. 11) and connected to form a closed ring by - 17 latching the latching hooks 24, 25 behind the latching lugs 28, 29.

The closed ring, whose ends are connected to one another with play, is secured against falling out by the closed ring shape in a simple annular groove 43 having a straight recess (Fig. 8). The play makes it possible tomatch the diameter of the ring to the respective mechanical load. The closing means are provided by modifying the elements which are provided anyway for the contact element. Overall, the invention has the following advantages: - The recess working (annular groove) is simple and inexpensive. No dovetail groove, T-groove or cutout is required for inserting (threading in) the contact element.

- The simple cross-sectional contour of the recess prevents disruptive accumulations of material during galvanization.

- No additional parts such as snap rings or holding strips are required for assembly.

- Attachment to the plug and to the socket is equally simple.

- No auxiliary tools are required for assembly.

- The space requirement is low.

- The closing means are part of the mounting strip, i.e. they are produced (attached) by being formed in the strip (piece goods).

- The changes to the circumference of the ring are absorbed by play.

LIST OF REFERENCE NUMERALS

10, 20, 30 Contact element (in the form of a strip) 11, 12 Peripheral web 13 Lamella 14, 15 Latching hook 16, 17 Accommodating device 18, 19 Latching lug - 18 21, 22 Peripheral web 23 Contact platelet 24, 25 Latching hook 26, 27 Accommodating device 28, 29 Latching lug 31 Central web 32, 33 Spring arm 34 Contact bridge Accommodating device 36 Latching lug 37 Latching hook 38 Slot 39 Mounting strip Plug connection 41 Plug 42 Socket 43 Annular groove (straight recess) 44, 44' Cutting line 45, 48, 49 Transverse web 46, 47 Web section x Play - 19

Claims

PATENT CLAIMS

1. Contact element (10, 20, 30) in the form of a strip which can be bent to form a ring, in particular for high currents, having two or more contact bodies (13, 23, 34), which are arranged one behind the other in the longitudinal direction, protrude from the plane of the contact element (10, 20, 30) and are spring-mounted perpendicular to the plane of the contact element (10, 20, 30), characterized in that closing means (14, ..., 19; 24, ..., 29; 35, ..., 37), which can be used to connect the ends of the contact element (10, 20, 30), which is bent in the form of a ring, to one another so as to form a closed ring, are provided on the contact element (10, 20, 30).

2. Contact element according to Claim 1, characterized in that the closing means (14, ....

19; 24, , 29; 35, , 37) are arranged at both ends of the contact element (10, 20, 30).

3. Contact element according to Claim 1 or 2, characterized in that the closing means (14, ....

19; 24, , 29; 35, , 37) can be connected in a latching manner.

4. Contact element according to Claim 3, characterized in that the closing means (14, ....

19; 24, , 29; 35, , 37) have, arranged at one end of the contact element (10, 20, 30), connection elements (14, 15; 24, 25; 37) which can be inserted in a latching manner into accommodating devices (16, ..., 19; 26, ..., 29, 35, 36), arranged at the other end of the contact element, in the circumferential direction of the ring. -

5. Contact element according to Claim 4, characterized in that the connection elements are in the form of latching hooks (14, 15; 24, 25; 37) extending in the longitudinal direction of the contact element (10, 20, 30).

6. Contact element according to either of Claims 4 or 5, characterized in that the contact element (10, 20, 30) comprises a mounting strip (11, 12; 21, 22; 39), which extends in the longitudinal direction and to which the contact bodies (13, 23, 34) are fixed, and in that the connection elements (14, 15; 24, 25; 37) and accommodating devices (16, ..., 19; 26, ..., 29, 35, 36) are integrally formed at the ends of the mounting strip (11, 12; 21, 22; 39).

7. Contact element according to Claim 6, characterized in that the mounting strip comprises two parallel peripheral webs (11, 12; 21, 22), between which the contact bodies (13, 23) are arranged, and in that the connection elements (14, 15; 24, 25) and accommodating devices (16, ..., 19; 26, ..., 29) are integrally formed at the ends of the peripheral webs (11, 12; 21, 22).

8. Contact element according to Claim 7, characterized in that the contact bodies are in the form of lamellae (13) running between the peripheral webs (11, 12), and in that the peripheral webs (11, 12) and lamellae (13) are produced by a stamping process from a common sheet metal strip

9. Contact element according to Claim 7, characterized in that the contact bodies are in the form of separate contact platelets (23) which are fixed to transverse webs (45, 48, 49) running between the peripheral webs (21, 22). - 21

10. Contact element according to Claim 6, characterized in that the mounting strip (39) comprises a central web (31), from which spring arms (32, 33), to which the contact bodies (34) are fixed, branch off laterally and in that the connection elements (37, 38) and accommodating devices (35, 36) are integrally formed at the ends of the central web (31) .

11. Contact element according to Claim 10, characterized in that the contact bodies are in the form of separate contact bridges (34) which are fixed to the ends of the spring arms (32, 33).

12. Contact element according to one of Claims 6 to 11, characterized in that the accommodating devices (16, ..., 19; 26, ..., 29, 35, 36) comprise two latching lugs (18, 19; 28, 29; 36) which are bent out in the transverse direction from the plane of the mounting strip (11, 12; 21, 22; 39) in the opposite direction, and in that each latching lug (18, 19; 28, 29; 36) has an associated connection element (14, 15; 24, 25; 37) which latches in behind the latching lug in the opposite direction.

13. Contact element according to one of Claims 6 to 12, characterized in that the mounting strip (11, 12; 21, 22; 39) is made of spring sheet metal, in particular of a Cu or Ni alloy or spring steel.

14. Contact element according to one of Claims l to 13, characterized in that the closing means (14, 35... , 19; 24, , 29; 35, , 37) are designed such that the spacing between the ends of the contact element (10, 20, 30) in the closed ring has a prescribed amount of play (x), preferably in the region of two or more millimetres. - 22

15. Method for the production of a contact element (20) according to Claim 1, which contact element (20) comprises a mounting strip (21, 22; 45, 48, 49) having at least one first web (21, 22) running in the longitudinal direction and two or more second webs (45, 48, 49) running transversely to the first web (21, 22), characterized in that the closing means (24, .. ., 29) are formed from sections of the at least one first web (21, 22) and the second webs (45, 48, 49) of the mounting strip (21, 22; 45, 48, 49).

16. Method according to Claim 15, characterized in that the closing means (24, , 29) have, arranged at one end of the contact element (20), connection elements (24, 25), which can be inserted in a latching manner into accommodating devices (26, 29), arranged at the other end of the contact element (20), in the circumferential direction of the ring, in that the connection elements are in the form of latching hooks (24, 25) extending in the longitudinal direction of the contact element (20), in that the accommodating devices (26, 29) comprise two latching lugs (28, 29) bent out in the transverse direction from the plane of the mounting strip (21, 22; 45, 48, 49) in the opposite direction, in that each latching lug (28, 29) has an associated latching hook (24, 25) which latches in behind the latching lug (28, 29) in the opposite direction, in that the latching hooks (28, 29) are each formed from a section of the first web (21, 22) and sections of a second web (49) which branch off from said first web, and in that the latching lugs (28, 29) are formed from web sections (46, 47) of a second web (45).

17. Method according to Claim 16, characterized in that the latching lugs (28, 29) are formed from - 23 web sections (46, 47) of a second web (45) by the web sections (46, 47) being bent through approximately 180 .

18. Method according to one of Claims 15 to 17, characterized in that, in order to achieve a prescribed amount of play (x) for the spacing between the ends of the contact element (20) in the closed ring, at least one of the second webs (45, 48, 49) is removed from the mounting strip (21, 22; 45, 48, 49).

19. Application of the contact element (10, 20, 30) according to one of Claims 1 to 14 in a plug connection (40), which comprises a hollow cylindrical socket (42) and a cylindrical plug (41) which can be inserted into the socket (42), characterized in that the contact element (10, 20, 30) is arranged as a closed ring in an annular groove (43) on the inner circumference of the socket (42) and/or on the outer circumference of the plug (41).

20. Application according to Claim 20 [sic], characterized in that the annular groove (43) is designed as a straight recess.