Combined connector contact

Abstract: A combined connector for providing charging current to a battery of a radio telephone comprises an electrically conductive charging pad contact, and a connector for receiving signals from a corresponding mating cable. The electrically conductive charging pad contact including means for releasably locking a mating cable against withdrawal from the combined connector.

Description: The invention relates to electrical connectors and in particular to combined connectors suitable for use in providing charging current for batteries in radio telephones. A combined connector provides means by which a charging current can be supplied to a radio telephone battery through a charging pad or through a charging contact designed for mating attachment with a cable. A separate single pin dc connector is typically also provided alongside the combined connector. Each of the connectors can be used independently to charge the battery. A mechanical arrangement is provided to prevent the different charging routes from being utilised simultaneously. Figure 1 illustrates a typical prior art multi-pin connector. Four sockets 1-4 are provided on the combined connector for attachment to a cable connector providing charging current along with two pins 5, 6 for providing radio frequency signals. A dc jack is provided alongside the combined connector contact for receiving direct current from the mains or from a car battery through cigarette lighter jack. In a typical cable connector four pins are provided for mating engagement with the four sockets of the combined connector contact A metal shield surrounds the pins and includes a pair of retaining arms, one on each side of the connector shield that mate with complementary recesses in metal plates held in place in the connector socket. Push buttons on the sides of the cable connector are provided to retract the retaining arms from engagement with the respective recesses in the metal plates to make withdrawal possible. Two charging pads 7, 8 are provided, one to each side of the multiple pin connector. In assembly these charging pads are threaded through the connector housing 9 and connected to the printed circuit board (pcb) of the radio telephone at the rear of the housing for coupling to the battery via contacts 10. The current flowing to the battery is controlled by an MCU to provide the desired regime for charging. The connector housing 11 is attached to the pcb by an adhesive. In accordance with the present invention there is provided a combined connector for providing charging current to a battery of a radio telephone comprising an electrically conductive charging pad contact and a signal connector for receiving signals from a complementary cable connector, the electrically conductive charging pad contact providing means for releasably retaining the cable connector against withdrawal from the combined connector The invention gives several advantages. By combining the function of the prior art retaining plate and charging pad contact in a single element, a significant saving can be made in the total area of the combined connector along with a reduction in the component count reducing the cost of the combined connector. The combined retaining plate/charging pad contact can additionally be utilised to firmly attach the connector to a printed circuit board. A leg can be provided that protrudes through the connector housing and extends to the pcb where it can then be soldered to the pcb to hold the combined connector contact firmly in position. With two such solder connections being possible, one from each of the charging pads, additional strength is provided. No adhesive is necessary for attachment to the pcb and this has the added advantage that a step in the manufacturing process is removed providing further cost advantages. By positioning the combined retaining plate and charging pad contact in a position to mate with retaining arms on the shield of a mating cable, the charging pad contacts with conductive shield of the mating cable. This means that the connector pins of the connector cable themselves will no longer need to supply charging current. This has two potential benefits, the number of pins on the connector can be reduced with attendant cost and space savings or alternatively, pins no longer necessary for charging can be used to provide additional signals without increasing the size of the connector. In accordance with a second aspect of the invention there is provided a connector arrangement for providing a charging current to a battery of a radio telephone comprising a combined connector including an electrically conductive charging pad contact and a signal connector, and a cable connector having a conductive shield and being arranged for mating engagement with the signal connector, the connector arrangement being such that signals from the cable connector are provided to the signal connector and current from the conductive shield is provided to the charging pad contact. In accordance with a third aspect of the invention there is provided a radio telephone having a combined connector for providing charging current to a battery, the combined connector comprising an electrically conductive charging pad contact and a signal connector for receiving signals from a complementary cable connector, the electrically conductive charging pad contact providing means for releasably retaining a complementary cable connector against withdrawal from the combined connector. The invention will now be described in greater detail with reference to Figures 2 to 10 of the drawings of which: Figure 2 a radio telephone having a combined connector of the invention; Figure 3 is a enlarged view of the connector of Figure 2; Figure 4 is a schematic representation of the circuit layout of the connector of Figure 3; Figure 5 is a schematic representation showing the connector of Figure 3 in relation to the printed circuit board of the radio telephone; Figures 6A and 6B is a perspective view of charging pad contacts; Figure 7 is an end view of a combined connector of another embodiment of the invention; Figure 8 is a top view of the combined connector contact of the Figure 7; Figure 9 is a schematic representation of a cable connector for providing charging current and signals to the combined connector of Figure 2; and Figure 10 is a schematic representation of a dc jack conversion module for use with connectors of embodiments of the invention In order to enable a radio telephone to receive both current for charging a battery and other signals, a connector is provided. It is important that this connector can receive charging current from all suitable forms of connector and also that it is kept as compact and simple as possible. Charging current is typically supplied in one of three ways, through a dc jack, through a cable connector or from a desk top charger through a charging contact. In the third case electrical contact is achieved by placing the charging contacts onto current carrying sprung contacts. In order that existing chargers employing any one or more of these types of contacts are not made obsolete it is important that radio telephones remain compatible with existing charging hardware. A connector on a telephone should, therefore continue to be compatible with a dc jack, a stand-in desk charger and a cable connector. In accordance with a first embodiment of the present invention, a radio telephone 19 having a combined connector 20 and a dc jack 18 is illustrated in Figure 2. The combined connector 20 can be seen in greater detail in Figure 3. The combined connector comprises charging pad connectors 21, 22 and a signal connector 23. The connector additionally has two radio frequency signal pins 24, 25. The signal connector 23 is designed to receive a mating cable connector 26 illustrated in Figure 9. Four signal pins 23, two charge pad contacts 21,22 and dc jack 18 can each be used independently to provide charging current to the battery. The radio telephone controls the supply of current from the connectors to the battery. Current flowing in each of the routes passes through a diode and is controlled by a cpu 17 (Figure 4). To accommodate the mating cable connector 26 (Figure 9), the combined connector 20 on the base of the phone 19 must provide a recess 27 to receive a conductive shield 28 of the cable connector 26 which typically has retaining arms 29 for securing the connection as well as signal sockets for mating with signal pins of the cable connector 26. In this embodiment of the present invention, the charging pads 21,22 of the combined connector 20 are disposed on a connector housing 30 along the wall of the recess 27 for receiving the conductive shield 28 of the cable connector 26. Electrically conductive contacts 31 (Figure 6) leading from the charging pads 21, 22 are disposed against the outer walls of this recess 27 and the conductive contacts 31 of the charging pad themselves provide respective holes 32 for receiving the retaining arms 29 of the conductive shield 28 to releasably retain the cable connector 26 in position. By combining the functions of charging pad contact 21,22 and releasable retaining means in one element the combined connector arrangement is much simplified. Each charging pad contact includes a leg 33 that protrudes through the housing 30 of the connector and is soldered to a printed circuit board (pcb) 34 (see Figure 5). In this way the connector housing 30 is pinned to the pcb 34 at two distinct points and solder provides for a firm attachment. In addition, as other component parts are soldered to the pcb during the manufacture of a radio telephone, the connector housing 30 can be attached to the pcb 34 at the same time as these other components dispensing with an assembly stage. To provide the required conduction characteristics the charging pad contact is preferably gold plated whereas the remainder of the contact is plated with tin or lead. The connector is assembled by inserting the charging pad contacts 21,22 into the recess in the direction of insertion of the mating cable connector 26. The charging pad contact illustrated in Figure 6A is held in position by arms 35 that engage in corresponding recesses on the base of the phone. The charging pad contacts of Figure 6B are retained in position by tangs 36 that prevent withdrawal through the front of the connector housing. Other means of attaching the charging pad contact to the connector housing could, however, be used instead. In the embodiment illustrated a dc jack 18 is provided adjacent the combined connector 20. However, with the charging contact 31 lining the wall of the recess 27 a module 38 incorporating a dc jack 39, such as that illustrated in Figure 10, can be used to adapt this arrangement to one which accepts current through a single pin dc plug. Contacts 40 on the outside of the module 38 provide for electrical coupling with the charging pad contacts 31. By inserting the dc jack module 38 into the recess 27 normally used to receive a cable connector, a dc pin can be used to supply charging current to a battery along the same route as current supplied via the charging pads. No permanent dc jack 37 is necessary and the mechanical arrangement for disabling the dc single pin charging route when not in use can be avoided. Finally the arrangement of this embodiment of the present invention allows a further advantage to be enjoyed with a minor modification to the connector cable 26 of Figure 9. By arranging for that cable connector 26 to supply charging current through the outer conductive shield 28, the connector pins 23 can either be reduced in number as the four pins typically used for charging are no longer necessary, or those pins could be used to supply signals of a different type without increasing the overall size or complexity of the system. The arrangement described above means that all charging current can be supplied through the charging pad contacts 21,22; 31 regardless of the source of current greatly simplifying control of the charging route. Figures 7 and 8 illustrate a second embodiment of the invention in which there is a single rf signal pin 29 instead of the two pins illustrated in the first embodiment. Otherwise the parts are alike. Like numerals are used to designate like parts. In view of the foregoing description it will be evident that various modifications may be made within the scope of the invention.

Claims: A combined connector (20) for providing charging current to a battery of a radio telephone comprising an electrically conductive charging pad contact (21,22) and a signal connector (23) for receiving signals from a complementary cable connector (26) the electrically conductive charging pad contact (21,22) providing means for releasably retaining the cable connector (26) against withdrawal from the combined connector (20). A combined connector according to claim 1 wherein the electrically conductive charging pad contact (21,22) is electrically coupled to the battery via conductive strips on a printed circuit board (34). A combined connector according to claim 2 wherein the combined connector is disposed in a housing (30) and mounted on the printed circuit board (34) and wherein the electrically conductive charging pad contact (21,22) further comprises a leg (33) arranged for pinning the housing to the printed circuit board (34). A combined connector according to claim 3 wherein the leg (33) is soldered to the printed circuit board (34). A connector arrangement for providing a charging current to a battery of a radio telephone comprising a combined connector (20) including an electrically conductive charging pad contact (21,22) and a signal connector (23), and a cable connector (26) having a conductive shield (28) and being arranged for mating engagement with the signal connector (23), the connector arrangement being such that signals from the cable connector (26) are provided to the signal connector (23) and current from the conductive shield (28) is provided to the charging pad contact (21,22). A connector arrangement according to claim 5 wherein the electrically conductive charging pad (21,22) includes means for releasably locking the cable against withdrawal from the signal connector (23). A connector arrangement according to claim 5 or 6 further comprising a dc jack converter (38) including means for coupling the electrically conductive charging pad connector (21,22) which a dc jack (39). A radio telephone having a combined connector for providing charging current to a battery, the combined connector comprising an electrically conductive charging pad contact (21,22) and a signal connector (23) for receiving signals from a complementary cable connector (26), the electrically conductive charging pad contact (21,22) providing means for releasably retaining the mating cable connector (26) against withdrawal from the combined connector (20).

Inventors: BROADFIELD GARY, SYRJALA MARKKU, BROADFIELD, GARY, SYRJALA, MARKKU
Applicants: HIROSE ELECTRIC CO LTD, NOKIA MOBILE PHONES LTD, HIROSE ELECTRIC CO., LTD., NOKIA MOBILE PHONES LTD.
Application year: 1995
Main classification: H01R13
IPC codes: H04B1, H01R13, H04Q7, H01R27, H02J7