BACKGROUND ART In the use of mobile or cell telephones in vehicles, the range may often be insufficient because of the screening effect of the vehicle body.

Vehicle-mounted cassettes are previously known in the art in which the mobile telephone proper may be snapped into position. Such a cassette has a contactor device for cooperation with a corresponding contactor device on the mobile telephone, there being connected to the contactor device of the cassette an external antenna which is placed exteriorly on the vehicle.

The cassette may also include connection capabilities for power supply or charging the mobile telephone, as well connection to a hands-free set.

In the connection of the external antenna, it is advantageous if the mobile telephone's own antenna can be disconnected from the mobile telephone's own circuits so that only the external antenna is connected to the mobile telephone when this is housed in the cassette.

In the switch device which realises the switching between the mobile telephone's own antenna and the external antenna, use has generally been made of various types

of spring elements where, for example, a helical spring has been usable in certain situations. However, in this context a helical spring is extremely unsuitable for at least two different reasons, viz., first a helical spring constitutes a coil which may disturb the function of the mobile telephone, and secondly helical springs have, because of their configuration, a marked tendency to tangle in one another if they are handled in bulk. This makes it as good as impossible, during an assembly process, to handle them in an automatically operating assembly line. This situation is not helped in this context by the fact that the helical springs under consideration here have a diameter of the order of magnitude of 1.5 mm and an unloaded length of 2-3 mm.

PROBLEM STRUCTURE The present invention has for its object to design the device intimated by way of introduction such that problems inherent in prior art technology are obviated. In particular, the present invention has for its object to remedy the serious problems that have defied ready solution in connection with assembly. The present invention also has for its object to design the device so that it will be totally unobjectionable in terms of electricity.

SOLUTION The objects forming the basis of the present invention will be attained if the device intimated by way of introduction is characterised in that the inner contactor member on the first contactor device is movable and impressible against the action of a spring element under the action of the inner contactor member on the second contactor device, the spring element comprising a non-metallic, elastically deformable material.

In one preferred embodiment, the device is further characterised in that the spring element consists of a hose or a tube of plastic or rubber material, such as a silicon rubber material.

Further advantages will be attained if the device according to the present invention is also given one or more of the characterising features as set forth in appended subclaims 3 to 9.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention will now be described in greater detail hereinbelow, with reference to the accompanying Drawings. In the accompanying Drawings: Fig. 1 is a vertical, approximately diametric, cross section through an antenna device intended to be mounted on a mobile telephone; Fig. 2 is a perspective view of a body portion included in the antenna device; Fig. 3 is a partial magnification of a lower region of Fig. 1; Fig. 4 is a side elevation, partly cut away to cross section, of an inner contactor member included in the antenna device of Fig. 1 ; and Fig. 5 shows the contactor member of Fig. 4 in perspective.

DESCRIPTION OF PREFERRED EMBODIMENT Fig. 1 shows a complete antenna which is intended to be mounted on a mobile telephone. The antenna has a body portion 1 which is shown in its entirety in Fig. 2.

The body portion consists of an electrically insulating and non-magnetic material, preferably a suitable plastic, and is composed of a first half 2 and a second half 3.

The two halves 2 and 3 are united by the intermediary of a snap connection and have a parting line 4 which approximately coincides with a diametric plane through the longitudinal axis of the body portion 1.

The body portion 1 serves for positionally fixing an antenna element 5 which, in the illustrated embodiment, consists of a helix element 5 with two different pitch

regions, hence an antenna element which may operate in two different frequency ranges.

The body portion 1 has a snap element 6 which is somewhat resilient in order to permit fixed snapping of the antenna in a corresponding snap coupling in the mobile telephone.

In its lower end, the antenna disposed on the mobile telephone has a contactor device 7 which, when the antenna is mounted on the mobile telephone, is accessible via an aperture in the casing of the mobile telephone. The contactor device 7 placed on the antenna device is designed for cooperation with a corresponding contactor device (a second contactor device) which is electrically connected to an external antenna which, as a rule, is placed externally on a vehicle. The second contactor device is placed in a cassette in which the mobile telephone may be secured and is placed and designed so as to realise contact with the first contactor device when the mobile telephone is inserted in and snapped in place in the cassette.

While it is an advantage if there is included in the invention a switch device which disconnects the antenna placed on the mobile telephone when the mobile telephone is fixed in the cassette and thus electrically connected to the external antenna, this is not an absolutely essential condition. In the embodiment which is to be described below, the switch function under consideration here is, however, included.

The first contactor device 7 disposed on the antenna of the mobile telephone has an inner and an outer contactor member 8 and 9, respectively. The inner contactor member 8 is movable and may be connected to the electric circuits of the mobile telephone, while the outer contactor member 9 is connected to earth.

Correspondingly, the contactor device electrically connected to the external antenna, the second contactor device, has an outer contactor member which is contactible with the outer contactor member 9 of the first contactor device 7 and is connected to the shield in the coaxial cable which interconnects the contactor device disposed on the cassette with the external antenna.

The contactor device placed on the cassette further has an inner contactor member which is contactible with the inner contactor member 8 of the contactor device placed on the antenna and which is connected to the central conductor in the coaxial cable which is connected to the external antenna.

The outer contactor member of the second contactor device (placed on the cassette) is of conical configuration so as to correspond to the conical configuration of the outer contactor member 9. Correspondingly, the inner contactor member of the second contactor device has a contact surface against which the end 10 of the contactor member 8 is urgable.

The inner contactor member 8 is elongate and has a contact end 10 which, on closing the two contactor devices, is subjected to an axial pressure in a direction to the left along the double-headed arrow 11. As a result, the contactor member 8 will, against the action of a spring element 12, be pressed in a direction to the left in Figs. 2 and 3 when the two contactor devices are compressed into contact position. The spring element 12 is produced from a non-metallic material and consists of an elastic or substantially elastic plastic or rubber material, such as a silicon rubber material. Such a material possesses superior elastic properties which do not appreciably vary within a large temperature range, for which reason this material is eminently well suited to function in an automobile where large temperature differences may occur.

The inner contactor member 8 is accommodated in a bore 13 in the second half 3 of the body portion 1. The bore 13 is cylindrical and has an end wall 14 in its end facing away from the contact end 10 of the contactor member 8. The end wall 14 has a through-going aperture through which the contactor device 7 is reciprocal in its longitudinal direction along the double-headed arrow. Further, as is most clearly apparent from Fig. 4, the contactor member has an annular projection 15 with a conical entry edge which, after mounting of the contactor member 8, prevents withdrawal therefrom through the aperture of the end wall 14.

For guiding the contactor member 8 in the bore 13, the contactor member has, in the region of its contact end 10, a radially projecting flange 16 which is of such diameter

that it can move substantially without play in the longitudinal direction of the bore 13 and guide against the peripheral wall of the bore.

On placing of the mobile telephone in the cassette, the two contactor devices will come into contact with each other, the inner contactor member 8 being displaced in its longitudinal direction in a direction to the left so that the left-hand end of the contactor member 8 in Figs. 3 and 4, an operating end 17, will arrive at a position which may approximately be marked by the broken line 18. As a result, the inner contactor member 8 will be connected to the circuits in the mobile telephone and thereby couple the external antenna to the mobile telephone.

The spring element 12, which counteracts the left-hand directed movement of the contactor member 8 consists, as was mentioned above, of a silicon rubber material, which is made with hose-or tubular configuration and which accommodates in itself a part of the contactor member 8. One end of the spring element 12 abuts against the projecting flange 16 of the contactor member, while the opposite end abuts against the end wall 14 of the bore 13. In the position illustrated in Fig. 3, which is a non- contact position but also, in spring terms, a rest position, the circumferential projection 15 on the operating end 17 of the contactor member 8 prevents the contactor member from being displace too far in a direction to the right so that it thereby is free of the bore 13.

On the manufacture of the spring element 12, this is taken from a running length of silicon rubber hose whose inner diameter is approximately as large as, or slightly larger than the diameter of the contact portion of the contactor member 8. The outer diameter of this hose is less than the diameter of the bore 13 and at least so much that the finished spring element 12 may be axially compressed a requisite distance, i. e. at least the relevant hose length (according to the double-headed arrow 11) for the contactor member 8 without being impeded by the circumferential surface of the bore 13.

The silicon rubber hose is moved in its longitudinal direction through a bore in a bracket which, in the longitudinal direction of the hose, is of a thickness which corresponds to the axial, unloaded length of the finished spring element.

On that side of the bracket facing towards the incoming hose, there is provided a reciprocating knife for cutting the hose.

Mounting of the contactor member 8 and the spring element 12 takes place with the spring element positionally fixed in the bracket, whereby both its position and its orientation are known, which greatly facilitates insertion of the contactor member 8.

The outer contactor member 9 is, as was mentioned above, electrically connected to earth in the mobile telephone and is in galvanic communication with a contact heel 19 which abuts against a corresponding, earthed contactor member in the mobile telephone.

It will be apparent from Fig. 1 that the antenna element 5 is galvanically connected to a contact plate 20 which, with a lower portion which serves the function of a fourth contactor member, connects to the side of the end wall 14 facing away from the bore 13. The contact plate 20 has a through-going aperture 21 which is dimensioned such that the operating end 17 of the contactor member 8 can move therethrough without electric contact. The above-mentioned third contactor member which is in communication with the circuits of the mobile telephone and which, under the action of a left-handed movement of the inner contactor member 8, may be moved to a position which is approximately indicated by the broken line 18, abuts under spring tension against the contact plate 20 when the inner contactor member 8 is located in rest position, i. e. in the position in Figs. 1 and 3 displaced a maximum distance to the right. The impression of the contactor member 8 thus realises that the above- mentioned third contactor member connected to the circuits of the mobile telephone is lifted away from the galvanic contact with the contact plate 20 and instead is in contact with the operating end 17 of the contactor member 8. The above-described construction thus offers a switch function which realises a disconnection of the antenna element 5 when the mobile telephone is placed in the cassette so that, instead, the external antenna alone is connected to the electric circuits of the mobile telephone.