Switching Assembly and Use Thereof in a Handheld Wireless Device For Remotely Activating A Remote Controlled System

Abstract

A handheld wireless device for remotely activating a remote controlled system, the handheld wireless device comprising: a casing holding an electrical energy store and circuitry including a transponder arranged to transmit a wireless signal in response to a request received from the remote controlled system; the handheld wireless device further comprising a switching assembly comprising: an electrical switch connected between the electrical energy store and the circuitry, the electrical switch operable by an applied magnetic field to switch the circuitry including transponder on and off; and a mechanical actuator mounted to the casing, the mechanical actuator operable to move a magnet relative to the electrical switch to operate the electrical switch; the mechanical actuator and magnet being located outside the casing and the electrical switch being located inside the casing.

Claims

1. A handheld wireless device for remotely activating a remote controlled system, the handheld wireless device comprising: a casing holding an electrical energy store and circuitry including a transponder arranged to transmit a wireless signal in response to a request received from the remote controlled system; the handheld wireless device further comprising a switching assembly comprising: an electrical switch connected between the electrical energy store and the circuitry, the electrical switch operable by an applied magnetic field to switch the circuitry including transponder on and off and a mechanical actuator mounted to the casing, the mechanical actuator operable to move a magnet relative to the electrical switch to operate the electrical switch; the mechanical actuator and magnet being located outside the casing and the electrical switch being located inside the casing.

2. A handheld wireless transmitter device according to claim 1 wherein the electrical switch comprises a reed switch.

3. A handheld wireless transmitter device according to claim 1 or 2 wherein the mechanical actuator is bonded to the outside of the case.

4. A handheld wireless device according to any previous claim wherein the mechanical actuator comprises a holder, and an actuator element to which the magnet is mounted; the actuator element being movable relative to the holder to move the magnet relative to the electrical switch.

5. A handheld wireless transmitter device according to any previous claim wherein the switching assembly comprises: a film of electrical insulator arranged between the electrical energy store and a terminal of the circuitry; a first electrical conductor that provides an electrical connection between the electrical energy store and the electrical switch; and a second electrical conductor that provides electrical connection between the terminal of the circuitry and the electrical switch.

6. A handheld wireless device according to claim 5 wherein the first and second electrical conductors are electrically conductive layers supported on and electrically isolated from one another by the film of electrical insulator.

7. A handheld wireless device according to claim 5 or 6 wherein the electrical switch is mounted on the film.

8. A handheld wireless device according to any previous claim wherein the switching assembly comprises: a further electrical switch; a motion sensor adapted to sense motion of the handheld device and to output a signal indicative thereof; and a controller arranged to receive the signal from the motion sensor; and to operate the further electrical switch to switch off the transponder in response to a determination that the wireless handheld device has been motionless for a predetermined period of time.

9. A handheld wireless device according to claims 5 and 8 wherein the motion sensor and controller are mounted on the film.

10. A handheld wireless device according to claim 8 or 9 wherein the controller is powered by the electrical energy store.

11. A handheld wireless device according to any previous claim wherein the remote controlled system is a remote controlled lock and/or remote controlled switch of a motor vehicle.

12. A switch assembly comprising: a film of electrical insulator, which when in use is, positioned between an electrical energy store and a terminal of circuitry to be powered by the battery; a first electrical conductor connected to a mechanical switch assembly to provide electrical connection between the electrical energy store and the mechanical switch assembly; and a second electrical conductor connected to the mechanical switch assembly to provide electrical connection between the circuitry terminal and the mechanical switch assembly; the mechanical switch assembly being operable, when the switch assembly is in use, to switch between a first state in which the electrical energy store and terminal are in electrical connection via the first electrical conductor and second electrical conductor, and a second state in which the electrical energy store and electrical terminal are electrically isolated from one another.

13. A switch assembly according to claim 12 wherein the mechanical switch assembly comprises: an electrical switch operable by an applied magnetic field; to switch between the first state and second state.

14. A switch assembly according to claim 13 wherein the switch assembly further comprises a mechanical actuator operable to move a magnet relative to the electrical switch to operate the electrical switch.

15. A switch assembly according to any claim 12-14 wherein the first and second electrical conductors are supported on and electrically isolated by the film of electrical insulator.

16. A switch assembly according to any claim 12-15 wherein the film comprises a first side that faces a first direction and a second side that faces a second, opposite direction; and, the switch assembly comprises a sandwich structure comprising the film interposed between a first electrical conductive layer that provides the first electrical conductor and a second electrical conductive layer that provides the first electrical conductor, the first electrical conductive layer supported on the first side of the film and a second electrical conductive layer supported on the second side of the film.

17. A switch assembly according to claim 16 wherein the thickness of the sandwich structure is not more than 0.2 mm.

18. A switch assembly according to claim 16 or 17 wherein the film is wider than the first connective layer and the second connective layer such that the film provides boarder portions adjacent the longitudinal edges of the first and second conductive layers.

19. A switch assembly according to any claim 12-18 wherein the film is longer that the connector to provide a tab at a longitudinal end of the first and second connectors.

20. A method of modifying an electronic device comprising a printed circuit board having a terminal that contacts a battery that powers the printed circuit board; the method comprising retrofitting to the electronic device a switch assembly comprising an mechanical switch assembly operable to electrically isolate the battery from the printed circuit board wherein the switching assembly further comprises a composite connector comprising a film of electrical insulator carrying a first electrical conductor on a first side and the second electrical conductor on a second side, and the method comprises positioning the composite connector between the battery and a terminal of the printed circuit board terminal such that the first conductor faces and is in electrical connection with the battery and the second electrical conductor faces and is in electrical contact with the printed circuit board terminal, the composite connector acting to electrically isolate the battery from terminal.

21. A method of modifying a handheld wireless device for remotely activating a remote controlled system, the handheld wireless device comprising: a transponder arranged to transmit a wireless signal in response to a request received from the remote controlled system; and the method comprising fitting an mechanical switch assembly operable to switch off the transponder so that it will not respond to a received request; wherein the mechanical switch assembly is fitted such that the mechanical switch assembly acts to electrically isolate a battery of the handheld wireless device from a printed circuit board carrying the transponder.

22. A method according to claim 21 comprising: positioning a film of electrical insulator between the battery and a electrical terminal of the printed circuit board; a first electrical conductor that provides an electrical connection between the battery and the switch; and a second electrical conductor that provides electrical connection between the printed circuit board terminal and the switch.

23. A method according to claim 22 wherein the film of electrical insulator carrying the first electrical conductor on a first side and the second electrical conductor on a second side, and the method comprises positioning the film between the battery and the terminal such that the first conductor faces and is in electrical connection with the battery and the second electrical conductor faces and is in electrical contact with the PCB terminal.

Description

[0057] FIGS. 1A-1C illustrate a hand held device 1 for activating a remote controlled system such as a remote controlled lock (and/or remote controlled switch). In an example embodiment the hand held device 1 is a key fob for a motor vehicle forming part of the motor vehicle's keyless entry system.

[0058] The device 1 comprises a case 2. The case 2 houses a printed circuit board (PCB) 3 that carries circuitry that includes a transponder 3A′ (shown notionally) adapted to receive a wireless signal from the remote controlled system and in response transmits a signal which when received by the remote controlled system causes said system to activate (e.g. unlock remote controlled lock, and/or open or close remote controlled switch).

[0059] The circuitry is powered by a battery 4 (or other electrical energy store), typically a button cell, via two electrical contacts 5A 5B of the PCB 3.

[0060] The device 1 optionally also includes a number of push button switches 6 operable by a user to cause the circuitry on the PCB 3 to carry out a number of pre-defined functions.

[0061] The hand held device includes a flexible switching assembly comprising a mechanical slide switch assembly 30 mounted on the outside of the case 2, and a reed switch 40 which is mounted on a composite film connector 50 housed within the case 2.

[0062] With reference to FIGS. 3A, 3B and 3C, the composite film connector 50 comprises a film 51 e.g. of polyester such as Myla(™) that carries on both sides, and thus interposed between, electrically conductive layers (e.g. of metal) patterned to define first and second electrically conductive traces 52, 53. The two conductive traces 52, 53 contact respective terminals 41 42 of the reed switch 40 which is mounted on the first side of the film 51.

[0063] The first electrically conductive trace 52 lies on a first side (that facing towards the reader in FIG. 3A) of the film 51. The second electrically conductive trace 53 lies on a second side of the film 51, its outline indicated by the dashed line on FIG. 3A and FIG. 3C. A via 54 through the film 51 provides electrical connection between the second electrical trace 52 and the reed switch 40 terminal. The first trace 52 and second portion 53B of the second trace are separated by a portion 51A of the film 51.

[0064] The composite film connector 50 comprises an enlarged portion 50A and a relatively narrow elongate portion or tail 50B. On the enlarged portion 50A, which is intended to be interposed directly between the battery 41 and PCB terminal 5B, the first and second traces are enlarged providing contact pads 52* 53* to allow for good electrical contact to be made between respectively the first trace 52 with the terminal of the battery 4, and the second trace 53 with the terminal 5A of PCB 3.

[0065] The composite film connector 50 comprises an outer electrical insulation layer 55, e.g. of epoxy resin, that covers both sides of the film 51 including and electrically conductive layers other than in the regions of the contact pads 52* 53* and reed switch terminals 41 42. The insulating layer 55 functions to protect the conductive layers and prevent short circuiting.

[0066] The thickness of the film with traces is favourably sufficiently small to allow it to be interposed between the circuitry terminal and battery without difficulty. A thickness of around 0.2 mm or less is preferred though up to 0.4 mm will still be effective.

[0067] The film 51 is broader than the traces 52, 53 to provide boarder portions 50C adjacent the traces 52 53 about their length.

[0068] The reed switch 40 is mounted on the elongate portion 50B, in this example about the terminus of the elongate portion 50B. This arrangement allows the reed switch 40 to be located remote from the battery 4 adjacent and/or against an inner wall of casing 2 in relatively close proximity to the mechanical slide switch assembly 30.

[0069] With the composite film connector 50 interposed between the battery 4 and connector 5A, direct electrical connection between the two is interrupted. Instead electrical connection between the two is made through a bypass circuit provided by the first conductive trace 52, second conductive trace 53 and reed switch 40 that connects between the first and second traces 52, 53; the reed switch 40 providing means to switchably open or close the bypass circuit to control whether the circuitry on the PCB 3 including transponder 3 is powered by the battery 4.

[0070] The mechanical slide switch assembly 30 comprises a holder 31 and an actuator member 32 arranged to slide a magnet 33, between two positions within the holder 31.

[0071] The holder 31 is arranged on an outside face of the case 2. The holder 31 includes a slot 31A and guide member(s) (not shown). The holder 31 may be bonded to the outer face of the case 2 using, for example, an adhesive, a hook and loop fastener or other means such as plastic welding.

[0072] These methods of mounting are favoured over those using a fastener that passes through the case 2, e.g. a screw or rivet as the latter require one or more holes to be formed within the case 2 which may compromise the degree of ingress protection to water and/or dirt provided by the case 2.

[0073] The actuator member 32 comprises a button 34 that extends through the slot 31A of the holder 30 allowing a user to slide the actuator member 32 and the magnet 33, which lies within the holder 31, about the guide member(s), between the two positions within the holder 31.

[0074] The reed switch 40 and mechanical slide switch assembly 37 are positioned so that when the magnetic actuator member 33 is in a first position, illustrated in FIG. 1A, the magnet 33 is relatively remote from the reed switch 40 such that the reed switch 40 is off, and that the action of moving the actuator member 32 to the second position (FIG. 1B) brings the magnet 33 into close enough proximity to the reed switch 40 as to turn it on.

[0075] FIGS. 2A and 2B illustrate the hand held device 1 with a variant switching assembly that includes a mechanical flip switch assembly 70 in place of the slide switch 30 of FIGS. 1A-1C.

[0076] The mechanical flip switch assembly 70 comprises a holder 71, and an actuator 72 that includes an arm 73 and pin 74 about which the actuator 72 is rotatably mounted to the holder 71. The arm 73 carries a permanent magnet 75 and is arranged to pivot about pin 74 against a fulcrum provided by the holder 71 so that the magnet 75 is moveable between a first position shown in FIG. 2A and second position shown in FIG. 2B to switch the reed switch 40 off or on.

[0077] The holder 71 may be mounted on an outside face of the case 2 in the same way as the holder 31 of the embodiment of FIG. 1.

[0078] In the embodiments of FIGS. 1 and 2 the reed switch is off when the magnet is remote from it and on when the magnet 75 is close to it. It will be appreciated that this arrangement could be reversed.

[0079] Further variations to FIGS. 1 and 2 are possible that use mechanical switch mechanisms other than slide or flip switches.

[0080] With reference to FIGS. 4A and 4B there is shown an alternative composite film connector 80 that carries switching circuitry 90 to provide additional functionality to the switch assembly.

[0081] The composite film connector 80 comprises a flexible film 81 of Mylar(™) or other suitable synthetic polymer that carries on both sides, and thus interposed between, electrically conductive layers (e.g. of metal) patterned to provide first, second and third electrically conductive traces 82, 83, 84. The patterning of the electrical conductive layer also provides connective traces for the switching circuitry 90.

[0082] The composite film connector 80 comprises a first and second enlarged portions 80A 80B connected by a relatively narrow neck portion 80C. A elongate ‘tail’ portion 80D extends from the second enlarged portion 80B.

[0083] With reference FIG. 4A, the first conductive trace 82 lying on a first side of the film, comprises a contact pad 82A on a first side of the first enlarged portion 80A and extends to a first terminal of the switching circuitry 90.

[0084] A second conductive trace 83 comprises a contact pad 83A on a second side of the second enlarged portion 80A (see FIG. 4B). The trace 83 extends to a second terminal of the switching circuitry 90.

[0085] 20 A third conductive trace 84 comprises a contact pad 84A on a second side of the first enlarged portion 80A (opposite contact pad 82A of the first trace 82) and extends to an input of the reed switch 40 though the switching circuitry 90.

[0086] The second and third conductive traces 83, 84 comprise portions that extend on both sides of the film 81 in order to bypass the other traces and/or the circuitry 90. Connection between said portions is made by connective vias through the film 81.

[0087] When installed, the first enlarged portion 80A is interposed between a first terminal of the battery 4 and the PCB terminal 5A such that the first trace 82 provides an electrical connection between the PCB terminal 5A and the first terminal of the circuitry 90, and the second trace 84 provide an electrical connection between the first terminal of the battery 4 and a terminal of the reed switch 40.

[0088] The second side of the second enlarged portion 80B is in contact with a second terminal (opposite polarity to first terminal) of the battery 4 such that that the third trace 85 provides an electrical connection between the second terminal of the battery 4 and the second terminal of the switching circuitry 90.

[0089] To provide this arrangement the film 51 is bent about the neck portion 80C so that the two enlarged portions lie against opposing faces of the (button cell) battery 4 with the neck portion 80 extending around the side of the battery 4.

[0090] FIG. 5 is a schematic of the circuit formed once the film connector 80 is installed as described above, together with functional components of the circuitry 90.

[0091] The circuitry 90 includes a controller 91, a clock 92, a motion sensor 93 and a electronic switch 94.

[0092] The circuitry 90 is powered by its connection to the two battery terminals provided by the second and third traces 83, 84.

[0093] The electronic switch 94 is arranged in series with the reed switch 40 such that the circuitry of the PCB 3 will only be powered when both the reed switch 40 and electronic switch 94 are closed.

[0094] The controller 91 is arranged to receive signals from the motion sensor 93 indicative of motion of the device 1, and clock signals from the clock 92. The controller 91 is programmed to use the received signal to switch the electronic switch 94 ‘on’ when motion of the device 1 is detected and to switch the electronic switch 94 ‘off’ following a period of time in which the device 1 is determined to be motionless.

[0095] This arrangement provides a means to switch the PCB circuitry off automatically. It can function as a failsafe mechanism in instances that the reed switch 40 is not turned off manually by a user operating the mechanical switch assembly 30, 70.

[0096] The motion sensor 93 may comprise one or more accelerometers. The electronic switch 94 may be comprised of one or more transistors.

[0097] In a variant design, power to the switching circuitry 90 may be arranged through the reed switch 40 such that the switching circuitry is only functioning when the reed switch 40 is on. This arrangement may prolong the life of the battery 4.

[0098] In a variant to any of the designs of FIGS. 1-5 the reed switch 40 may be replaced with a Hall Effect switch or other magnetically actuated switch. Notwithstanding, a reed switch is preferred to a Hall Effect switch as it physically opens the circuits when switching to an off state.

[0099] In a further, though less favourable, variant design the composite film connector could be used to connect to an electrical switch other than a magnetically operable one, e.g. a simple slide or push button switch which extends through the casing in order to be operable by a user.