GB2309848A

GB2309848A - Contact members for mobile telephones and/or chargers

Info

Publication number: GB2309848A
Application number: GB9601939A
Authority: GB
Inventors: David Clelland
Original assignee: Nokia Mobile Phones Ltd
Current assignee: Nokia Oyj
Priority date: 1996-01-31
Filing date: 1996-01-31
Publication date: 1997-08-06
Anticipated expiration: 2016-01-31
Also published as: GB2309848B; GB9601939D0

Abstract

A portable handset (Figures 1 to 9) has a plastics casing 10,12 enclosing a circuit board 14. The rear part 12 has two recesses 20 shaped to receive, with a push-fit, respective metal contact members 16. Each contact member has a spring arm 22 terminating in a first contact region 24 which resiliently engages the circuit board 14. Each contact member 16 also has a second contact region which presents an externally accessible contact face 28, the battery pack of the handset being charged through the pair of contact faces 28. Another embodiment (Figures 10 to 16) of the invention is a charger for charging the battery pack of the portable handset. The charger has a pair of metal contact members 56 each of which has a spring arm 58 engaging a circuit board 54 in the charger and a contact face 62 through which the battery pack of a portable handset 76 is charged. In each case the spring arm engagement of the contact member with the printed circuit board avoids the need for a soldered connection and simplifies assembly.

Description

RADIO TELEPHONES AND ACCESSORIES THEREFOR This invention relates to parts for assembly into radio telephones in the form of portable handsets for use in cordless or cellular radio telephone systems. The invention is also concerned with parts for assembly into chargers for charging the batteries of such handsets.

A known portable handset has a printed circuit board carrying most of the electrical circuitry and electronic components of the handset. The printed circuit board is enclosed within a casing which carries, adjacent its lower edge, spaced contact members presenting accessible charging faces for charging the battery of the portable telephone. Inside the casing, the contact members make electrical connection with the printed circuit board and this connection has conventionally been achieved by soidering.

Similarly, a known charger has a printed circuit board carrying most of the electrical circuitry and electronic components of the charger. The printed circuit board is enclosed within a casing which carries spaced contact members presenting accessible charging faces for engagement with the charging faces on a portable handset, for the purpose of charging the battery of the handset.

Inside the casing, the contact members make electrical connection with the printed circuit board and this connection has conventionally been achieved by soldering.

The invention aims to provide an interconnection (between the contact members and the printed circuit board of a portable handset or a charger) which is simpler and cheaper than the known soldered connections.

According to one aspect of the invention there is provided a set of parts for assembly into either a radio telephone in the form of a portable handset, or an accessory therefor, the set comprising a plastics casing part, a metal contact member and a printed circuit board having an electrical contact pad, the contact member having a mounting region, a first contact region and a second contact region, the mounting region being shaped with respect to a receiving location on the casing part so that the contact member is prevented from separating from the casing part when the contact member has been placed in position with respect to the casing part, the first contact region being connected to the mounting region by means of a spring arm, on assembly of the casing part, the metal contact member and the printed circuit board the first contact region resiliently engaging the contact pad as a consequence of the resilience of the spring arm and the second contact region presenting an electrical contact face accessible from an external side of the casing part.

According to another aspect of the invention a radio telephone in the form of a portable handset comprises a plastics casing, a printed circuit board enclosed in the casing and two spaced electrical contact members, each contact member having a mounting region by which the contact member is located in and supported by the casing, a first contact region connected to the mounting region by means of a spring arm and a second contact region, each first contact region resiliently engaging a corresponding contact pad on the printed circuit board by virtue of the resilience of the associated spring arm and each second contact region presenting an externally accessible contact face for charging a battery of the radio telephone.

According to a yet further aspect of the invention there is provided a charger for charging a battery pack of a radio telephone in the form of a portable handset, the charger comprising a plastics casing, a printed circuit board enclosed within the casing and two spaced electrical contact members, each contact member having a mounting region by which the contact member is located in and supported by the casing, a first contact region connected to the mounting region by means of a spring arm and a second contact region, each first contact region resiliently engaging a corresponding contact pad on the printed circuit board by virtue of the resilience of the associated spring arm and each second contact region presenting an externally accessible contact face for engagement with a corresponding contact member on the handset for charging the battery pack of the latter.

A portable handset according to the invention and a charger according to the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an isometric exploded view of the parts of the portable handset, Figure 2 is an isometric view, to an enlarged scale, showing a printed circuit board, two contact members and one casing part of the handset, Figure 3 illustrates the assembly of the two contact members in the casing part, Figure 4 is a fragmentary sectional view through one end of the handset on a plane through one of the two contact members, Figure 5 is an isometric view of a representative one of the two contact members, Figure 6 is a side view of the contact member of Figure 5, Figures 7 to 9 are views of the contact member looking in the directions of the arrows VII, VIII and IX respectively in Figure 6, Figure 10 is an isometric exploded view of the parts of the charger, Figure 11 is a sectional view of the charger, through a plane including one of the two contact members and also illustrating a portable handset being slid into position on the charger for the purpose of charging a battery in the handset, Figure 1 2 is an isometric view of one of two contact members of the charger, Figure 1 3 is a side view of the contact member of Figure 12, and Figures 14 to 16 are views of the contact member looking in the direction of the arrows XIV, XV and XVI respectively in Figure 13.

The components of the portable handset are shown in exploded view in Figure 1. They comprise a plastics front casing part 10 and a plastics rear casing part 1 2 which are attached together to enclose internal components, notably a printed circuit board 14 carrying the electronic components and circuitry of the handset. Referring to Figure 2, the rear casing part 12 and two identical metal contact members 16 are first assembled together to form a sub-assembly. This operation is illustrated in Figure 3 which shows the two contact members 1 6 being pushed, in the direction of arrows 18, into spaced recesses 20 moulded in the rear casing part 12. Subsequently, the sub-assembly of the rear casing part 12 and the two contact members 16 is brought down onto the printed circuit board 14. The two casing parts 10 and 12 are then permanently secured together to enclose the printed circuit board 14 and other internal components.

Each recess 20 is shaped in relation to the shape of the corresponding contact member 16, so that when the contact members 1 6 are pushed into their respective recesses 20, the contact members 1 6 are retained in position and do not drop out in subsequent handling and transport of the sub-assembly, or in final assembly of the remaining parts of the portable handset.

Each of the two contact members 1 6 is as shown in Figures 5 to 9. The contact member 1 6 is fabricated from a single piece of gold-plated phosphor bronze about 0.2mm thick, having a central stem one end of which narrows and forms a spring arm 22, bent as shown in Figures 5 and 6 and terminating in an upturned first contact region 24. The wider end of the stem is bent through slightly more than a right-angle to form a knee 26. From the bent length 28 of the stem, two side flanges 30 are folded back so that lower edges 32 of the flanges abut the stem to increase rigidity. The edge 38 of each flange 30 remote from the stem is locally deformed to provide an outwardly projecting barb 34 of generally triangular shape. Also, the upper edge of each flange 30 is stepped at 36.

Each recess 30 in the casing part 12 has side walls spaced so that when the contact member 16 is pushed into the recess the barbs 34 engage the recess walls to give an interference fit which prevents the contact members, once inserted, falling out of the recesses. In the inserted positions of each contact member 16, the outer face of the bent back length 28 of the stem forms an externally accessible contact face. The recess has a ledge or step, behind which the steps 36 engage, to prevent the contact member being prised out of the casing part eg by a sharp instrument. Also, the vertical edges 38 of the flanges are in close relationship to an inner wall of the recess, so resisting excessive inward pressure on the contact member. The neat folding of the edges 32 against the stem avoids any gaps which might otherwise cause the contact members (when in a bundle prior to assembly) becoming entwined with one another.

The spring arms 22 project downwardly from the main body of the casing part.

To protect the spring arms 22 and the contact regions 24 the casing part has integrally moulded triangularly shaped projections 40 (Figure 2) which extend beside the respective spring arms.

When the sub-assembly of casing part and contact members is finally assembled with the remaining components, the contact regions 24 engage spaced contact pads 42 (Figure 4) on the printed circuit board 14, this causing the spring arms 22 to be resiliently deflected to cause the contact regions 24 to engage the pads 42 with a resilient spring action which maintains electrical interconnection between the contact members 1 6 and the pads 42. The contact faces 28 are externally accessible at the lower edge of the handset and serve as means for charging the battery pack of the handset.

Figure 10 shows the components of the charger stand in exploded view, to illustrate the orientation of the parts during assembly. The charger comprises two plastics casing parts, namely a base 50 and a cover 52 which are assembled together, with an intervening printed circuit board 54, and with the parts inverted. Two metal contact members 56 are first located in respective recesses in the cover 52, the printed circuit board 54 and the base 50 then being brought into position, the final engagement of the base 50 and the cover 52 ensuring correct orientation and retention of the contact members 56 in the assembled charger.

A representative one of the contact members 56 is shown in Figures 1 2 to 1 6.

The contact member 56 is in one piece and is of beryllium copper coated all over with gold. The member 56 has a central stem one end of which extends downwardly in a spring arm 58 terminating in a first contact region 60 for engagement with the printed circuit board. The other end is doubled back to form a second contact region 62 forming an accessible charging contact face.

Intermediate the two ends the contact member has a mounting region of cruciform shape, opposing flanges 64 being bent downwardly but diverging slightly. The centre of the cruciform shape has a circular hole 66.

Each recess in the cover 52 has side walls spaced so that when the corresponding contact member 56 is pushed into the recess the diverging flanges 64 engage the side walls with a resilient spring action to provide an interference fit to prevent the inserted contact member falling out of the recess.

Also, each recess has, projecting from its base, an upstanding and integrally moulded cylindrical pin 68 which locates in the hole 66 of the inserted contact member 56. With the contact members 56 thus retained (although not necessarily finally positioned) with respect to the cover 52, the printed circuit board 54 and the base 50 are placed into their assembled positions. When this is done, the printed circuit board 54 deflects the spring arms 58 of the contact members 56 so that the contact regions 60 resiliently engage spaced contact pads 70 (Figure 11) on the printed circuit board 54. Also, the base 50 has spaced projecting lugs 72 with semi-circular section grooves 74 (Figure 11) moulded therein at a position such that when the base 50 is assembled onto the cover 52, with the intervening printed circuit board 54, the ends of the lugs 72 push the cruciform areas of the contact members into the bases of the recesses, the semi-circular grooves receiving the respective pins 68. This finally locates and retains the contact members 56 in their required positions.

In the assembled position, the contact regions 62 provide externally accessible contact faces for engagement with the electrical contact faces (comparable with contact faces 28 of Figure 4) on the lower end of a portable handset 76 (Figure 11). When the portable handset 76 is slid into position in the cradle 78 of the cover 52, as shown in Figure 11, the two contact faces on the handset 76 resiliently engage the contact regions 62 on the charger. To prevent excessive inward movement of the contact members 62 into the charger, the base 50 has surfaces 80. The charger cover 52 also has a recess 82 to receive a battery pack, for charging of the latter.

In both the portable handset and the charger, the use of contact members having spring arms which resiliently engage the printed circuit board avoids the need for a solenoid connection between the contact members and the printed circuit board. This, together with the push fit of the contact members in the casing part, simplifies assembly.

The present invention includes any novel feature or combination of features disclosed herein either explicitly or any generalisation thereof irrespective of whether or not it relates to the claimed invention or mitigates any or all of the problems addressed.

In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

Claims

1. A set of parts for assembly into either a radio telephone in the form of a portable handset, or an accessory therefor, the set comprising a plastics casing part, a metal contact member and a printed circuit board having an electrical contact pad, the contact member having a mounting region, a first contact region and a second contact region, the mounting region being shaped with respect to a receiving location on the casing part so that the contact member is prevented from separating from the casing part when the contact member has been placed in position with respect to the casing part, the first contact region being connected to the mounting region by means of a spring arm, on assembly of the casing part, the metal contact member and the printed circuit board the first contact region resiliently engaging the contact pad as a consequence of the resilience of the spring arm and the second contact region presenting an electrical contact face accessible from an external side of the casing part.

2. A set of parts according to claim 1, wherein the metal contact member is one of two such members and the casing part has two spaced receiving locations, the printed circuit board having spaced contact pads for respective engagement with the first contact regions of the contact members.

3. A set of parts according to claim 2, wherein each contact member is a push-fit in the corresponding location.

4. A set of parts according to claim 3, wherein each receiving location is a recess in the casing part and each contact member has side flanges which are an interference fit in the corresponding recess.

5. A set of parts according to any of claims 2 to 4, wherein each contact member is fabricated in a single piece, the mounting region being intermediate the first and second regions.

6. A set of parts according to any of claims 2 to 5, wherein the casing part is part of a portable handset, the second contact regions being used to charge a battery pack of the mobile handset.

7. A set of parts according to claim 6, wherein the casing part and the contact members form a sub-assembly and the casing part has projections shaped and positioned to protect the spring arms and first contact regions of the contact members.

8. A portable handset made from a set of parts according to any of claims 1 to 7.

9. A set of parts according to any of claims 2 to 5, wherein the casing part is part of a charger for charging a battery pack in a mobile telephone handset, the second contact regions being accessible to make electrical contact members with the electrical contact members on the mobile telephone handset.

10. A set of parts according to claim 9, wherein the set comprises a second casing part which is engageable with the first mentioned casing part, the two casing parts enclosing the printed circuit board and the interengagement of the second part with the first part providing additional support and location for the contact members.

11. A set of parts according to claim 10, wherein receiving locations of the first casing part have integrally moulded pins and the mounting region of each contact member has a hole, the pin projecting through the hole when the contact member is mounted in the first casing part.

12. A charger made from a set of parts according to any of claims 1 to 5, 9, 10 or 11.

13. A radio telephone in the form of a portable handset comprising a plastics casing, a printed circuit board enclosed in the casing and two spaced electrical contact members, each contact member having a mounting region by which the contact member is located in and supported by the casing, a first contact region connected to the mounting region by means of a spring arm and a second contact region, each first contact region resiliently engaging a corresponding contact pad on the printed circuit board by virtue of the resilience of the associated spring arm and each second contact region presenting an externally accessible contact face for charging a battery of the radio telephone.

14. A charger for charging a battery pack of a radio telephone in the form of a portable handset, the charger comprising a plastics casing, a printed circuit board enclosed within the casing and two spaced electrical contact members, each contact member having a mounting region by which the contact member is located in and supported by the casing, a first contact region connected to the mounting region by means of a spring arm and a second contact region, each first contact region resiliently engaging a corresponding contact pad on the printed circuit board by virtue of the resilience of the associated spring arm and each second contact region presenting an externally accessible contact face for engagement with a corresponding contact member on the handset for charging the battery pack of the latter.

15. A portable handset constructed and arranged substantially as herein particularly described with reference to the accompanying drawings.

1 6. A charger for a portable handset, the charger being constructed and arranged substantially as herein particularly described with reference to the accompanying drawings.