AU2013330203B2 - Remotely operable push button - Google Patents

Abstract

A button for an electrical device is disclosed. The button has a button portion which can be physically pressed, a moveable portion which moves from a first position to a second position when the button portion is pressed, biasing means which is operable to bias at least the movable portion to the first position and actuating means operable from a remote location which functions to move the movable portion from the first position to the second position without the button portion being physically pressed. The actuating means may include a solenoid, and electromagnetic interactions caused by operation of the solenoid may move the movable portion from the first position to the second position. The biasing means may be magnetically operated, or operated by a flexible/resilient component, or operated in some other way.

Description

PCT/AU2013/001135 WO 2014/056021

REMOTELY OPERABLE PUSH BUTTON

TECHNICAL FIELD

[0001] The present invention relates generally to electrical switches, and particularly (although not necessarily exclusively) button or pushbutton type electrical switches.

BACKGROUND

[0002] It is to be clearly understood that mere reference herein to previous or existing apparatus, products, systems, methods, practices, publications or any other information, or to any associated problems or issues, does hot constitute an acknowledgement or admission that any of those things (individually or in any combination) formed part of the common general knowledge of those skilled in the field or are admissible prior art.

[0003] Reference will initially be made, by way of introductory background, to pushbutton type switches like those conventionally used on prison cell intercoms. In many areas, it is a requirement that each cell in a prison must have an intercom. This is so that inmates in each cell can communicate with prison guards or other prison personnel. For example, if there are multiple inmates in a given cell and one of the inmates in the cell experiences a medical emergency, another inmate in the cell can use the cell’s intercom to alert the prison staff. Or, even if there is only one inmate per cell, if an inmate in one cell sees or recognises that another inmate in a nearby cell may be experiencing a medical emergency, the first said inmate can use the intercom in his/her cell to alert prison staff to assist the other inmate. Of course, the intercoms may also be used by inmates to alert and/or communicate with prison personnel in a range of other situations such as, for example, in the event of a fire or other emergency, or threatening or dangerous behaviour by one person towards another, etc. These are just a few examples of the myriad possible uses for the prison intercom.

[0004] Generally, the intercom provided in each prison cell is an audio intercom which has internal operating electronics, a speaker, a microphone and a pushbutton type switch. In order to operate an intercom, a person (e.g. inmate) need simply press the intercom's pushbutton and thereupon a communication link is established between that intercom and the prison guard/personnel station, or between the intercom and a communications centre or some other point in the intercom system. The intercom’s WO 2014/056021 PCT/AU2013/001135 2 microphone will then transmit all spoken messages (and other sounds) it receives, and any replies etc (e.g. from the prison guards/personnel) will be emitted from the intercom’s speaker.

[0005] In prison intercom systems such as the ones described above, it is not sufficient for each cell to simply have an intercom. It is also necessary for the intercom in each cell to be operational (i.e. in functional working order). Consequently, regular inspections or checks of each intercom (i.e. the intercom in each cell as well as intercoms in any other locations in the prison) are required to ensure that each one is in working order. Systems have previously been proposed for enabling certain aspects of the operation of intercoms to be tested remotely. So, for example, systems have been proposed which allow the internal operating electronics, speaker and microphone of each intercom to be tested from a remote location and without the need for a person to physically inspect and test each one. Systems have also been proposed which allow components (and indeed the full communications link) between the intercom and, for example, the central/master intercom/centre to be tested to ensure that communication is possible therebetween. However, to date, systems have not allowed remote testing of aspects of the intercom operation which depend on physical operation/manipulation by a person. In particular, it has not been possible to test whether the pushbutton on each intercom is working (i.e. works when pressed) without physically inspecting and testing (i.e. pressing) each one. As a result, it has generally been necessary for a person (e.g. a prison guard or maintenance staff member) to physically inspect and manually test the pushbutton of each intercom in a prison on a regular basis. Given that prisons often have hundreds of prison cells (and consequently hundreds of intercoms), the regular testing of each intercom can be time consuming, labour intensive, and consequently expensive (e.g. due to labour costs etc). It may therefore be desirable if the need to physically inspect and manually test the pushbutton of each intercom could be alleviated or reduced.

SUMMARY OF THE INVENTION

[0006] The current inability to remotely test and confirm the operational status of a pushbutton (and the associated components/electronics) has been described above in the context of prison intercom systems. However, it is to be clearly understood that the invention is by no means limited to that particular application and indeed may find use in a range of other areas. Other applications where the invention might be used WO 2014/056021 PCT/AU2013/001135 3 include, for example, intercom' systems in multi-dwelling residential complexes (e.g. building security door/entry intercoms), intercom-like devices used as electronic security "help points” or information points such as those commonly found in public areas like train stations, bus stops and the like, buttons used to call elevators in large office blocks, etc. These are just a few examples, and the invention may find use or application in myriad other possible areas as well. Also, for the avoidance of doubt, the invention is not necessarily limited to use in intercom or intercom-like applications, and may also find use in a range of other applications in which it would be desirable to be able to remotely test and confirm the operational status of a pushbutton (and possibly also the associated components/electronics).

[0007] The invention, at least in certain embodiments, relates broadly to a button for an electrical device, the button having a button portion which can be physically pressed, a moveable portion which moves from a first position to a second position when the button portion is pressed, biasing means operable to bias at least the movable portion to the first position, and remotely operable actuating means operable to move the movable portion from the first position to the second position without the button portion

I being physically pressed, wherein the button causes or allows the electrical device to perform a particular (predetermined) function, or to operate in a particular (predetermined) manner, when the movable portion moves into the second position.

[0008] Buttons in accordance with the present invention will generally be used on, or used to operate, electrical devices. There is no limitation whatsoever on what the electrical devices could be. Indeed, as explained above, buttons in accordance with the present invention could be used to operate prison cell intercoms, or they could alternatively be used to operate myriad other kinds of electrical/electronic devices. Ultimately, buttons in accordance with the present invention could potentially be used on, or used to operate, almost any kind of electrical/electronic device which includes a button which is operated by being physically pressed.

[0009] Buttons in accordance with the present invention will generally include a button portion which can be physically pressed. Generally, this will be the part or portion of the button which a user can physically press on or push (e.g. using a finger or thumb etc) to operate the button. There will also generally be a movable portion of the button which moves from a first position to a second position when the button portion is pressed or pushed. The movable portion and the button portion may be on or part of PCT/AU2013/001135 WO 2014/056021 4 one and the same component, or they could be separate components. If separate components, the button portion and the movable portion may be directly connected together, or indirectly connected (e.g. by one or more intermediate components) or they may be linked in a manner such that the movable portion is caused to move from the first position to the second position when the button portion is pressed. This will be discussed further below.

[0010] For the avoidance of doubt, the distance the movable portion moves may vary depending on the nature/type of the button. For example, in many embodiments, the distance the movable portion moves between the first and second position may be in the order of millimetres (say, for example, 0.5-7mm). However, the distance moved could also be much smaller. For example, in the case of so-called "piezo-buttons" or buttons which operate using the piezoelectric effect, the distance could be in the order of a few micrometres (pm a.k.a microns).

[0011] As explained above, when the movable portion of the button moves into the second position, this will generally cause or allow the electrical device to perform a particular function, or to operate in a particular manner. In other words, when the button is pressed thereby causing the movable portion to move into the second position, this will generally cause the electrical device to operate in whatever way, or to do whatever it is designed/configured to do, when the button is pushed. Referring to the prison cell intercom example, pressing the button on one intercom may cause a communication link to be established between that intercom and one or more other intercoms. However, this is merely an example and it will be clearly understood that there is absolutely no limitation on the kind or nature of the function performed by the electrical/electronic device (whatever it may be), or on the way or manner in which it operates, when the button is pushed. Indeed, those skilled in this area will appreciate that the kind of function performed, or the way in which an electrical/electronic device can operate, when a button is pushed is potentially limitless.

[0012] In buttons according to the present invention, biasing means may also be provided to bias at least the movable portion to the first position. Thus, for instance, when the movable portion is moved from the first position to the second position, the biasing means may function to push or urge at least the movable portion back to (or towards) the first position. For the avoidance of doubt, the biasing means need not \ necessarily connect to or act directly on the movable portion. It could, instead, connect PCT/AU2013/001135 WO 2014/056021 5 to or act on another part, portion or component of the button, and this may in turn cause the movable portion to be urged towards (or back towards) the first position. Also, there is no limitation whatsoever on the form which the biasing means may take. In other words, any means or mechanisms capable of causing at least the movable portion to be biased (i.e. urged) toward the first position may be used. By way of example, a mechanism involving some form of resilient component (e.g. a spring, elastomeric component, membrane, etc) or multiple or a combination thereof may be used. Alternatively, for example, pressure could be used whereby the button might include, say, a sealed chamber or other volume containing pressure above ambient pressure, and this relatively higher pressure could be what urges the movable portion back towards the first position. As another possibility, magnetic (or magnetically operated) biasing means may be used.

[0013] Buttons in accordance with embodiments of the present invention will generally also include actuating means. The actuating means should be operable to move the movable portion from the first position to the second position without the button portion being pressed. In other words, the actuating means may cause the movable portion to move in the same way as if the button were physically pressed by a user, but without requiring the user to do so. Importantly, the actuating means should be remotely operable. That is, it should be possible to cause the actuating means to operate from a location remote from the button itself. This is so that, if it is required or desired to test the button to confirm its operational status (i.e. to confirm that it works when pressed), the actuating means can be triggered from a remote location and thereby cause the movable portion to move from the first position to the second position (i.e. just as if the button portion had been pressed), but without the need for the button portion to actually be physically pressed. Put another way, the actuating means may enable the button to be "remotely pressed"; that is, to be triggered from a remote location and to behave just as if the button portion had been pressed, but without the need for a person to be physically present at, and to physically push the button portion. Those skilled in the art will appreciate that this may assist in enabling remote testing/checking of buttons.

[0014] As mentioned above, in some embodiments, the biasing means which is operable to bias at least the movable portion of the button to the first position may be magnetic (or magnetically operated). In certain specific embodiments, there may be a movable portion magnet which is connected directly or indirectly to the movable portion WO 2014/056021 PCT/AU2013/001135 6 and which moves with the movable portion. The button may further include, or have associated therewith, a second magnet. The movable portion magnet and the second magnet may create a repulsive force therebetween and said repulsive force may operate to bias the movable portion to the first position. The movable portion, or a part thereof, may be magnetic such that the movable portion itself, or the said part thereof, is (or forms) the movable portion magnet. However, other configurations are also possible where the movable portion magnet is separate from but connected (directly or indirectly) to the movable portion. The second magnet may be fixed in position relative to the button. In other words, whereas certain parts or portions of the button (e.g. the button portion and the movable portion) may move when the button is pressed etc, ofher parts and portions of the button may remain fixed at all times. The second magnet may be a component (or part of a component) which falls into the latter category. Suitably, one of the movable portion magnet and the second magnet may be a permanent magnet, or both may be permanent magnets. In embodiments where at least the movable portion magnet is a permanent magnet, the movable portion magnet / may be a rare earth magnet.

[00151 Embodiments of the invention may also be provided in which the biasing means is non-magnetic (i.e. not magnetically operated). A number of possible examples of non-magnetic biasing means are given above. For the avoidance of doubt though, the forms of non-magnetic biasing means that may be used are not limited to the examples given above. In fact, there is no limitation whatsoever on the kind of nonmagnetic biasing means could be used. Nevertheless, it is envisaged that in some embodiments non-magnetic biasing means in the form of a flexible or resilient component could be used. The flexible or resilient component could be, for example, a flexible or resilient membrane. In some embodiments, one or both of the button portion and the movable portion of the button may be at least partly housed within a first (front) housing of the button, and the resilient membrane may extend between the button portion and an inside portion of the first housing, or between the movable portion and the inside portion of the first housing. More often, the resilient membrane may extend between the button portion and the inside portion of the first housing, and the membrane may then provide a seal between the button portion and the inside portion of the housing.

[0016J The button portion may be connected either directly or indirectly to the movable portion and it may move with the movable portion. The movable portion may WO 2014/056021 PCT/AU2013/001135 7 also, at least in certain embodiments, move linearly between the first position and the second position. In these embodiments, the movable portion may comprise an elongate component having a principal axis corresponding to its longest dimension, and the direction of the movable portion's movement may be parallel to, or collinear with, said principal axis. In certain particular forms of these embodiments, the movable portion may comprise a plunger rod. The plunger rod may be cylindrical or some other elongate shape. The button portion may be formed as a separate component from the plunger rod, and the button portion and the plunger rod may be connected to form at least part of a movable plunger or plunger assembly (being a sub-assembly of the overall button assembly).

[0017] As explained above, buttons in accordance with embodiments of the present invention should include actuating means. Any suitable components, mechanisms, systems, arrangements or other means (or any combination thereof) able to function as described above may be used. Therefore, there is no limitation whatsoever on the nature or kind of actuating means that may be used, or on the form or configuration which it may take. It is envisaged that in some embodiments, the actuating means may include a solenoid and the magnetic field created when an electric current flows through the solenoid may interact with the magnetic field of the above-mentioned movable portion (or movable portion magnet) causing the movable portion to move from the first position to the second position. It is also envisaged that, often, the above-mentioned plunger rod may be magnetic and it may be positioned at least partly inside the solenoid.

[0018] It is explained above that when the movable portion of the button moves into the second position, this will generally cause or allow the electrical device to perform a particular function, or to operate in a particular manner. Therefore, some means or mechanisms should be provided so that electronics associated with the button are caused to signal that the button has been pressed when the movable portion moves into the second position. Any suitable means or mechanisms may be used for this purpose. For example, known forms of electrical contacts may be used such that when the movable portion moves into the second position it engages with an electrical contact, or an electrical connection is otherwise made, which in turn causes electronics associated with the button to signal that the button has been pressed. A range of known piezoelectric mechanisms may also be used. WO 2014/056021 PCT/AU2013/001135 8 [0019] Other arrangements may also be used. For instance, in some embodiments, thé button may further include one or more components operable to emit electromagnetic radiation, and also one or more components operable to receive at least part of said emitted electromagnetic radiation, and when the moveable portion moves into the second position said flow of electromagnetic radiation may be blocked, or at least partially interrupted, or the way it is received may be altered, and this may cause electronics associated with the button signal that the button has been pressed. {0020] In some slightly more specific embodiments, a sender and a receiver may be provided, and there may be a space between the sender and the receiver. A part of the movable portion may become positioned at least partially in the space between the sender and the receiver when the movable portion is in the second position. The sender may be operable to send electromagnetic radiation across the space between the sender and receiver, and the receiver may be operable to receive the electromagnetic radiation. When the movable portion is in the second position, the above-mentioned part of the movable portion may break or interrupt the flow of electromagnetic radiation from the sender to the receiver, whereupon electronics associated with the button may signal that the button has been pressed. The movable portion may be a plunger rod as described above, and therefore the above-mentioned part of the movable portion (i.e. the part which breaks or interrupts the flow of electromagnetic radiation) may be an end of the plunger rod. The electromagnetic radiation may take the form of an infrared beam sent by the sender across the space between the sender and the receiver, and the receiver may be operable to receive the beam. Electronics associated with the button may be operable signal that the button has been pressed when beam is broken or interrupted.

BRIEF DESCRIPTION OF THE DRAWINGS f .

[0021] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows: [0022] Figure 1 illustrates a pushbutton assembly in accordance with an embodiment of the invention. In Figure 1 the button assembly is shown in isolation. WO 2014/056021 PCT/AU2013/001135 9 [0023] Figure 2 is an exploded illustration of the button assembly in Figure 1. \ [0024] Figure 3 illustrates the way the button assembly in Figure 1 can be mounted. Figure 3 is, in fact, a view from the inside of a shell/casing of an intercom or other device to which the button assembly is mounted.

[0025] Figure 4 a cross-sectional view of the button assembly in Figure 1.

[0026] Figure 5 illustrates the plunger assembly which forms part of the button assembly in Figure 1.

[0027] Figure 6 is an exploded view of the plunger assembly in Figure 5.

[0028] Figure 7 also relates to the button assembly according to the embodiment shown in Figure 1, and specifically Figure 7 illustrates the back of the button assembly's rear housing and also a pair of infrared receivers which form part of the assembly’s photo interrupter.

[0029] Figures 8a and 8b help to illustrate the operation of the photo interrupter shown in Figure 7.

[0030] Figure 9 helps to illustrate the operation of the button assembly in Figure 1 when the button is pressed.

[0031] Figure 10 is a schematic representation of circuitry used to interface between the button assembly and the relevant host system controls.

[0032] Figure 11 helps to illustrate the logical states of the circuitry input and outputs in different modes of operation.

[0033] Figure 12 illustrates a pushbutton assembly in accordance with another embodiment of the invention.

[0034] Figure 13 is an exploded illustration of the button assembly in Figure 12. DETAILED DESCRIPTION

[0035] Figure 1 illustrates the assembly of a button in accordance with an embodiment of the invention. For the purposes of this Detailed Description section, the assembled button assembly shown in Figure 1 may be referred to as an STB unit 1. ) PCT/AU2013/001135 WO 2014/056021 10 STB stands for "self-testing button". The terms "button", "button assembly", "STB unit" and "STB" therefore generally refer to the same thing and are interchangeable, unless the context implies otherwise.

[0036] From Figure 2, which is an exploded illustration of the STB unit 1 in Figure 1, it can be seen that the STB unit 1 includes a front housing 10, a rubber O-ring 20, a button member 3Ö, a magnetic plunger rod 40, a grub screw 37, a solenoid coil 50, a solenoid housing 60, a rear housing 70, a PCB (printed circuit board) 80 and four holding screws 90.

I

[0037] The front housing 10 is a mostly cylindrical component. It will generally be m'ade from stainless steel, although it could also be made from a range of other similar materials. The main cylindrical body 11 of the front housing 10 has an external thread as shown in Figures 1 and 2. In this particular embodiment, the threaded body 11 has a 16mm outer diameter and an M16 thread. Of course, other sizes and thread types may also be used. The front housing 10 also has a circular front face (or faceplate portion) 12. The outer diameter of the front face 12 (19mm in this embodiment) is slightly larger than the diameter of the threaded body 11, and the front face 12 forms a flat front end of the front housing 10. There is also a cylindrical through-bore 13 extending axially through the front housing 10. It can be seen from Figure 4 that the through-bore 13 in the front housing 10 has a stepped configuration in that it has a larger diameter 13b towards the rear of the front housing which steps down to a smaller diameter 13a near the front. More specifically, the front/forward portion 13a of the through-bore 13 which forms a circular opening in the front face 12 and which extends approximately a quarter of the way back through the front housing 10 has a smaller diameter than the rest of the through bore 13b. When the STB unit is assembled, the through-bore 13 receives the plunger assembly which is described below.

[0038] As illustrated in Figure 6, the plunger assembly is made up of the rubber O-ring 20, the button member 30, the plunger rod 40 and the grub screw 37. Figure 6 is an exploded view of the plunger assembly, whereas Figure 5 shows the plunger assembly in an assembled state. Referring first to the button member 30, this is the component which forms the actual "button". In other words, the button member 30 is the component which a user will physically press to operate the STB unit. The button member 30 will generally be made from stainless steel, although a range of other similar materials could also be used. The front end 31 of the button member 30 is PCT/AU2013/001135 WO 2014/056021 11 rounded (approximately hemispherical in shape in this embodiment). When the STB unit is fully assembled, the rounded front end 31 of the button member protrudes through and proud of the front face 12 of the front housing 10 (i.e. it protrudes through the circular hole in the front face 12) as shown in Figures 1 and 4. The rounded front end 31 is therefore the portion which a user can physically press. The rear end 33 of the button member 30 (i.e. the end opposite the rounded front end 31) is cylindrical and slightly larger in diameter than the rest of the button member. In fact, as shown in Figure 4, the rear end 33 of the button member has a larger diameter than the smaller-diameter front portion 13a of the through-bore 13 in the front housing 10. This prevents the button member (and hence the plunger assembly) from sliding out through the front of the front housing 10 when the STB unit is assembled with the plunger assembly inserted in the through-bore 13.

[0039] There is also a circumferential groove 32 formed in the button member 30. The groove 32 is just behind the rounded front end 31 (i.e. in between the rounded front end 31 and the cylindrical rear end 33) and forms a cylindrical region of smaller diameter than the rest of the button member. When the plunger assembly is assembled, the O-ring 20 is located in the groove 32 as shown in Figure 5, and when the STB unit is fully assembled the O-ring 20 contacts and forms a seal against the internal wall of the smaller-diameter front portion 13a of the through-bore 13 in the front housing 10. This seal prevents ingress of water, dust, etc, into the assembled STB unit. There is also a blind bore 34 formed in the back of the button member 30, and a small transverse threaded hole 35 through the side of the button member (specifically through the cylindrical portion 33) which opens into the blind bore 34. Neither the blind bore 34 nor the transverse hole 35 are visible in Figures 5 and 6. However they are represented in the cross-sectional view in Figure 4. From Figure 4, it can therefore be appreciated that when the plungef assembly is assembled, the magnetic plunger rod 40 inserts into the blind bore 34 in the rear of the button member 30, and the grub screw 37 then screws into the transverse threaded hole 35 and engages firmly against the side of the plunger rod 40, thereby securing the plunger rod 40 to the back of the button member 30.

[0040] When the STB unit is assembled, the plunger assembly is assembled as described above, and is then inserted into the front housing 10. Specifically, the plunger assembly is inserted, from the rear, into the through-bore 13 in the front housing 10 such that the round end 31 of the button member projects out through the WO 2014/056021 PCT/AU2013/001135 12 hole in the front face 12 of the front housing. The front housing 10 together with the plunger assembly may be considered to form a front assembly 100.

[0041] Also, when the STB unit is assembled, components including the solenoid coil 50 and the solenoid housing 60 are housed inside the rear housing 70. The PCB 80 is also attached to the back of the rear housing 70. These components, together with the rear housing 70 and screws 90, may be considered to form a rear assembly 110.

[0042] The components of the front assembly 100, and the components of the rear assembly 110, are differentiated in Figure 2.

[0043] Before the STB unit is installed (i.e. before it is mounted on or to the shell/casing of the intercom or other device which the button is to operate), the components of the front assembly 100 will be assembled together, and likewise the components of the rear assembly 110 will be assembled together. However, the front assembly 100 and rear assembly 110 will remain separated from each other for the initial stages of the STB unit's installation. This will be discussed further below.

[0044] From Figure 2, it can be seen that the rear housing 70 is a generally hollow cylindrical component with an internal thread 71. The gauge of thread 71 matches the gauge of the thread on the body portion 11 of the front housing 10 (meaning that in the particular embodiment illustrated in Figure 2 the thread 71 is a 16mm diameter M16 thread). It will therefore be appreciated that the rear housing 70 (and hence the assembled rear assembly 110) can screw onto the back of the front housing 10 (thus connecting the rear assembly 110 to the front assembly 100) as illustrated in Figures 1 and 4. However, as mentioned above, the rear assembly 110 will not initially be screwed onto the front assembly 100.

[0045] Rather, in order to install the STB unit on or to the casing of the intercom or other device, a hole will be formed or provided in the intercom/device casing. Note that this hole is not illustrated in any of the Figures, although the inside of the intercom/device casing wall is illustrated (designated by reference numeral 4) in Figure 3. The said hole in the device casing will have a diameter which is slightly larger than the diameter of the threaded body portion 11 of the front housing 10 but smaller than the diameter of the front housing's front face 12. When the STB unit is to be installed, the front assembly 100 will be inserted from the outside through the hole in the device WO 2014/056021 PCT/AU2013/001135 13 casing 4 such that the threaded body 11 inserts through the hole into the inside of the casing. However, the faceplate 12 of the front housing 10 is larger than the hole in the device casing and therefore the faceplate 12 prevents the front assembly 100 from sliding all the way through the hole into the inside of the casing.

[0046] Once the front assembly 100 has been inserted through the hole in the device casing 4 as described above, a locknut 15 (illustrated in Figure 3) is screwed all the way onto the threaded portion 11 and engages with the inside surface of the casing 4, thereby firmly securing the front assembly 100 to the casing 4. After that, the rear assembly 110 can be Screwed onto the back of the front assembly 100 inside the device casing, and finally the necessary wiring (as illustrated in Figure 3) can be connected to the rear of the PCB 80 to complete the electrical aspects of the installation.

[0047] The rear assembly 110 and its components will now be discussed further with reference to Figures 2 and 4.

[0048] From Figure 2, it can be seen that the solenoid 50 comprises a length of conducting material (copper wire or the like) wound to form a tight helical coil. The two straight ends of the conductor (51 and 52) both extend parallel to the axis of the coil and point towards the rear of the assembly.

[0049] It can also be seen from Figure 2 that the solenoid housing 60 comprises a generally cylindrical component which has a cylindrical hollow 61 therein. However, from Figure 4, it can be seen that the large diameter section of the hollow 61 (as visible in Figure 2) does not extend all the way through the solenoid housing 60. Rather, the hollow 61 effectively terminates at a flat back face 62 of the solenoid housing 60. There is, however, a hole 65 extending through the back face 62 of the solenoid housing. The diameter of the hole 65 is slightly larger than the diameter of the magnetic plunger rod 40. This is so that the plunger rod 40 can extend through the hole 65 when the STB unit is fully assembled. Also, on the flat back face 62 of the solenoid housing 60, there are a series of small blind threaded holes 63. The threaded holes 63 are arranged around the hole 65. There are, in fact, four holes 63 but not all of them are visible in Figure 4.

[0050] Referring next to the rear housing 70, as explained above, the rear housing 70 is a generally hollow cylindrical component with an internal threaded portion 71. WO 2014/056021 PCT/AU2013/001135 14

However, from Figure 4, it can be seen that the internally-threaded portion 71 does not extend all the way through the rear housing 70. Rather, the threaded portion 71 effectively terminates at a flat back face 72 of the rear housing 70. There is, however, a hole 75 extending through the back face 72 of the rear housing. The diameter of the hole 75 is slightly larger than the diameter of the magnetic plunger rod 40. This is so that the plunger rod 40 can extend through the hole 75 when the STB unit is fully assembled. Also, on the flat back face 72 of the rear housing 70, there are a series of small through holes 73. The through holes 73 are arranged around the hole 75. Again, there are four holes 73 but not all are illustrated (except in Figure 7). There is also a disc-shaped recess 76 formed in the back face 72 on the rear of the rear housing 70. The recess 76 provides space between the back of the rear housing 70 and the PCB 80 to accommodate components of the STB unit's photo interrupter, as discussed below.

[0051] When the rear assembly 110 is assembled, the through-holes 73 in the back of the rear housing 70 align with the blind threaded holes 63 in the back of the solenoid housing 60 and also with screw holes 83 in the PCB 80 (see Figure 2). Therefore, when the rear assembly 110 is assembled, the screws 90 are inserted through the screw holes 83 in the PCB 80, through the holes 73 in the back of the rear housing 70 and they thread into the threaded holes 63 in the back of the solenoid housing 60. This secures the solenoid housing 60, the rear housing 70 and the PCB 80 together. At the same time, the solenoid coil 50 is housed within the hollow 61 in the solenoid housing 60, and the straight ends 51 and 52 of the solenoid windings insert through small holes 64 in the solenoid housing 60 (see Figure 9) and also through small holes 74 in the rear housing 70 (see Figure 7) to ultimately insert into the holes 84 (see Figure 2) which form the electrical contact points in the PCB 80.

[0052] As mentioned above, the STB unit includes a photo interrupter. The operation of the photo interrupter can be understood from Figures 7, 8a and 8b. The photo interrupter includes an infrared sender 120 and an infrared receiver 130. Both are electrically connected to, and powered by, the PCB 80. The sender 120 and receiver 130 are mounted in the recess 76 which is on the back of the rear housing 70. The sender 120 and receiver 130 may be physically mounted to either the PCB 80 or to the rear housing 70, but in any case they are mounted in the space 76 between the rear housing 70 and the PCB 80. The sender 120 and receiver 130 are also positioned diametrically opposite each other on either side of the hole 75 (recall that the plunger rod 40 inserts through the hole 75). The sender 120 is operable to send an infrared PCT/AU2013/001135 WO 2014/056021 15 beam which is received by the receiver 130. Therefore, as illustrated in Figure 8a, when the plunger assembly (and in particular the plunger rod 40) is in an "un-pushed" or "un-actuated" position inside the STB unit, the end of the plunger rod 40 does not insert between the sender 120 and receiver 130 and therefore the infrared beam between the sender and receiver is uninterrupted. However, when the plunger assembly is pushed or moved inwards (either by a user pushing on the button member 30 or by operation of the self-testing functionality discussed below) the plunger rod 40 moves inward such that the end of the plunger rod 40 inserts between the sender 120 and the receiver 130 breaking/interrupting the infrared beam as illustrated in Figure 8b. When the beam is broken/interrupted, the STB unit's electronics operate to signal that the button has been pushed.

[0Q53] It should be noted that, in this embodiment (and any other embodiments that use a similar photo interrupter), there is no need for a physical electrical connection (or even physical contact) between the plunger assembly and other parts of the unit in order for the unit to signal that the button has been pushed. Therefore, there are no physical or electrical contacts or the like which can wear out, fail, etc.

[0054] The way that the STB unit’s plunger assembly (i.e. the button member 30, plunger rod 40, etc) can move will now be described. The "un-pushed" or "un-actuated" position of the plunger assembly is illustrated in Figures 1,4 and 9. In this position, the front-end 31 of the button member 30 projects out through the front of the front housing 10, although the rear end 33 of the button member engages with the ridge formed by the stepped diameter change in the through-bore 13 inside the front housing (recall that this prevents the plunger assembly from sliding out through the front of the front housing). From Figures 4 and 9, it can be seen that when the plunger is in this "un-pushed" or "un-actuated" position, there is a space 16 between the back of the button member 30 and the front of the solenoid housing 60. When a user presses the button by pressing on the rounded front-end 31 of the button member (or when the plunger assembly is moved by the STB unit's self-testing functionality) the plunger assembly moves rearwardly until the back of the button member 30 contacts with the front of the solenoid housing 60. In the particular embodiment shown, the width of the space 16,, and hence the distance travelled by the plunger assembly, is 1.5mm. As explained above, when the plunger assembly moves in this way, the end of the plunger rod 40 inserts between the sender 120 and the receiver 130 of the photo interrupter breaking/interrupting the infrared beam and causing the unit's electronics to signal that WO 2014/056021 PCT/AU2013/001135 16 the button has been pushed.

[0055] The plunger assembly is naturally biased to return to the "un-pushed" or "unactuated" position. Therefore, after the plunger assembly has been pushed (or moved) as described above, the plunger assembly will then naturally return to the "un-pushed" or "un-actuated" position. In order to understand how this natural bias comes about in this embodiment, it should first be recalled that the plunger rod 40 is magnetic. That is, the plunger rod 40 will comprise a permanent magnet, and preferably a permanent magnet of the rare earth type (i.e. made from an alloy of one or more rear earth elements). Rare earth magnets are generally known for having strong, concentrated magnetic fields. (Using a stronger magnet for the plunger rod 40 may also reduce the necessary size of the solenoid 50 required to perform the self-testing functionality discussed below.) The PCB 80 also incorporates a permanent magnet (not illustrated). The magnet which forms the plunger rod 40, and likewise the magnet in the PCB 80, should be oriented so as to repel each other. Specifically, the two magnets should be oriented with their respective north poles towards each other, or alternatively with their respective south poles towards each other, so as to create a repulsive force between the two. In any case, this repulsive force is what causes the plunger assembly to naturally move away from the PCB 80 and hence return to the "un-pushed" or "unactuated" position.

[0056] The STB unit's self-testing functionality will now be described. As mentioned above, the two ends 51 and 52 of the solenoid conductor insert into the holes 84 in the PCB 80. As has also been mentioned, the holes 84 form electrical contacts/connections between the PCB 80 and the solenoid 50. Accordingly, when the STB unit's self-testing functionality is activated, the electronics associated with the STB unit cause an electrical current to flow through the PCB 80 and the solenoid 50. In Figure 9, the end 51 of the solenoid is shown connected to the positive terminal and the end 52 shown connected to the negative terminal. When the current flows through the solenoid 50, this creates a magnetic field within and around the solenoid. Recall also that the plunger rod 40 is magnetic and is inserted through/inside the windings of solenoid 50 in the assembled STB unit. Consequently, the magnetic field created by the flow of current through the solenoid 50 interacts with the magnetic field of the plunger rod 40.

[0057] Importantly, the direction in which the conductor is wound to form the coil of WO 2014/056021 PCT/AU2013/001135 17 the solenoid 50 will depend on the orientation of the plunger rod magnet. For instance, if the plunger rod magnet has its north pole facing towards the rear of the assembly, the solenoid 50 should have coils wound in one direction, whereas if the plunger rod magnet has its south pole facing towards the rear of the assembly the solenoid 50 should have coils wound in the opposite direction. (This is to ensure that the solenoid magnetic field and plunger magnetic field interact to move the plunger in the correct direction.) Recall also that the orientation of the plunger rod magnet should be such that a repulsive force is created between the plunger rod and the permanent magnet in the PCB 80. In any case, the solenoid 50 should be configured (i.e. with coils wound in the appropriate direction given the plunger rod's orientation) such that when an electrical current flows through the solenoid 50 the magnetic field induced around the solenoid 50 interacts with the magnetic field of the plunger rod 40 to force the plunger rod 40 to move towards the rear of the STB unit (i.e. in the same direction as if a user had pressed the button by pressing on the front end 31 of the button member). The force of this current-induced magnetic interaction is sufficiently large to overcome the repulsive magnetic force between the plunger rod 40 and the permanent magnet in the PCB. Consequently, when the STB unit's self-testing functionality is activated, current flows through the solenoid 50 and the resulting magnetic interaction causes the plunger assembly to move towards the rear of the unit, and when the plunger assembly moves in this way, the end of the plunger rod 40 inserts between the sender 120 and the receiver 130 of the photo interrupter breaking/interrupting the infrared beam and causing the unit's electronics to signal that the button has been pushed.

[0058] Those skilled in the art will recognise that the STB unit described above forms the button of a single electronic device (e.g. a single intercom). The said device (intercom) will, of course, normally be part of a larger system or network in which multiple such devices (intercoms) are linked. In the case of intercoms, this allows communication between respective intercoms etc. The system/network will also have operating controls ("host controls") separate from and in addition to the respective buttons associated with individual STB units. In applications where the present invention is used, these host operating controls (or "host controller") should enable/allow the self-testing function of individual STB units (as described above) to be initiated/performed remotely. For instance, the system should allow a signal to be sent to the PCB 80 of individual STB units to initiate the above-describe self-testing function. This could be done by a user to manually operating the host controls to initiate self- WO 2014/056021 PCT/AU2013/001135 18 testing (typically of a number of, or all, STB units at once or in rapid succession) from a remote location, or the system may be configured so that the host controls automatically initiate the self-testing. In either case, self-testing should preferably be performed at regular intervals.

[0059] Of course, the system should also be configured such that, when self-testing is initiated, if a particular STB unit does not return a signal indicating that its button has been pushed, an alert or notice is issued for a qualified person to inspect that STB unit, check it and perform repairs etc if necessary. Preferably, the system should also produce and retain a testing record. For example, a record of the (or each) date and time when self-testing of STB units was performed (or if the self-testing is only performed for certain STB units the record should also indicate which ones). The record should also indicate, for each STB unit and for each self-testing instance, whether the self-testing revealed that the STB unit was operational, and if not it should further record whether (and what) action was taken. This record may therefore provide an inspectable and auditable resource. In the case of intercom systems used in prisons and the like, this may allow the prison facility to comply with (and if necessary demonstrate that it has complied with) requirement for maintaining and checking the operational status of all intercom buttons (STB units).

[0060] Figures 10 and 11 will be used to provide a brief general overview of the operation of circuitry which may be used to interface between an individual STB unit 1 (or the alternative STB unit 300 described below) and the above-referenced host operating controls. As illustrated in Figure 10, each individual STB unit 1/300 may have an associated control circuit 2 which interfaces between the STB unit and the host controls and is responsible for charging, control and measurement.

[0061] The control circuit 2 operates using transistor-transistor logic (TTL). The control circuit 2 is powered by the host power supply and is triggered by the host operating controls (e.g. a host microcontroller). The supply voltage which powers the control circuit 2 is labelled Vcc in Figure 10. This is also the power which, in turn, is used to power the STB unit 1/300.

[0062] The control circuit 2 has three means of communication, namely one input and two outputs. The input may be referred to as the 'Trigger input" or "Trigger" and it provides instructions for charging and STB unit operation. When “Trigger” is high, the WO 2014/056021 PCT/AU2013/001135 19 control circuit 2 is charged and ready for operation. On the other hand, bringing “Trigger” low triggers the solenoid activating the STB unit's self-testing function. “Trigger” must be held low for a minimum duration of one second to allow for a complete discharge.

[0063] The first output of the control circuit 2 may be referred to as the "Ready output" or "Ready" and it provides feedback to the host microcontroller regarding the status of the device. After “Trigger” is initiated and held high, the circuit will begin charging. When fully charged the “Ready” output will read low indicating that device is ready to be activated.

[0064] The second output of the control circuit 2, namely the “Pushed output" or "Pushed”, returns a low signal when the button has been activated through either a physical depression of the button, or via the solenoid-operated self-testing function.

Signal Input / Output Description Logic Trigger Input Multifunction control pin 1 Charge and hold 0 Trigger and disable Ready Output Device ready signal 1 Not yet ready to trigger 0 Ready to Trigger Pushed Output Button press return signal 1 Button Open Circuit 0 Button Closed Circuit [0065] Referring to Figure 11, it will be seen that the control circuit 2 together with its associated STB unit 1/300 has two modes of operation, namely "Ready" and "Standby". In “Ready” mode, the control circuit 2 is available to be triggered for operation without delay. “Ready” mode is established by holding the trigger pin high keeping the circuit charged. Through keeping the circuit charged a small amount of power may be dissipated. In the particular embodiment described, the amount of power discharged is approximately 50 mW. In “standby" mode, the devices’ control circuit 2 is disabled until required. “Standby" mode is established by holding the trigger pin low until operation is required.

[0066] Figures 12 and 13 illustrate the assembly of an STB unit 300 in accordance with an alternative embodiment of the invention. The main difference between the STB unit 300 in Figures 12 and 13 and the embodiment of the STB unit 1 described with WO 2014/056021 PCT/AU2013/001135 20 reference to Figures 1-9 above is that, whereas the biasing means in the STB unit 1 in Figures 1-9 was magnetically operated, the biasing means used in the STB unit 300 is non-magnetic. Otherwise, many of the components of the STB unit 300 are similar to, and much of its functionality is the same as in the STB unit 1. Therefore, the STB unit 300 in Figures 12 and 13 need not be described in as much detail as the STB unit 1 above.

[0067J From Figure 13, which is an exploded illustration of the STB unit 300 shown in Figure 12, it can be seen that the STB unit 300 includes a button member 330, a resilient silicon rubber membrane 320, a front housing 310, a retaining clip 349, a plunger coupling 347, a magnetic plunger rod 340, a rear housing 370 (a.k.a. actuator housing 370), an O-ring 361, a solenoid coil (not illustrated) housed inside a solenoid housing 360, a spacer 303, a photo interrupter assembly 302, a PCB (printed circuit board) 380 and five holding screws 390.

[0068] Similar to the STB unit 1 described above, the STB unit 300 may be said to be made up of a front assembly 400 and a rear assembly 410. The components of the front assembly 400, and the components of the rear assembly,410, are differentiated in Figure 13. The front assembly 400 includes the button member 330, the resilient rubber membrane 320, the front housing 310, the retaining clip 349, the plunger coupling 347 and the magnetic plunger rod 340. The rear assembly 410 includes the rear housing 370, the O-ring 361, the solenoid housing 360 containing the solenoid, the spacer 303, the photo interrupter assembly 302, the PCB 380 and the holding screws 390.

[0069] The front housing 310 is a mostly cylindrical component. It may be made from stainless steel or a range of other materials. The main cylindrical body 311 of the front housing 310 has an external thread as shown in Figures 12 and 13. The threaded portion 311 is configured to screw into the corresponding internally threaded portion in the front of the rear housing 370 (see Figure 13). The front housing 310 also has a circular front face 312. The outer diameter of the front face 312 is slightly larger than the diameter of the threaded body 311, and the front face 312 is slightly tapered so that it forms a slightly tapering front end of the front housing 310. There is also a cylindrical through-bore 313 extending axially through the front housing 310. As can be made out in Figure 13, the through-bore 313 has a stepped configuration. Specifically, the front/forward portion of the through-bore 313 which forms a circular opening in the front face 312 has a larger diameter than portions further into the through-bore 313. (Note: WO 2014/056021 PCT/AU2013/001135 21 this is different to the stepped configuration of the through-bore 13 in the other embodiment described above where the through-bore 13 was narrower at the front.) The ridge 314 formed by the step change in diameter in the through-bore 313 is just visible in Figure 13.

[0070] When the front assembly 400 is assembled, the silicon rubber membrane 320 is first inserted (mounted) onto the cylindrical rear end of the button member 330. The retaining clip 349 is then inserted (mounted) onto the cylindrical rear end of the button member 330 following (i.e. after) the membrane 320. The retaining clip 349 locks into the notch on the back of the button member 330 securing the membrane 320 to the button member and preventing the membrane 320 from sliding off the back of the button member. The button member 330, membrane 320 and retaining clip 349 (which are then held together) are then inserted into the front of the through-bore 313 in the front housing 310 so that the flat front of the button member 330 is approximately flush with the front of the front housing 310 (as illustrated in Figure 12). Also, when the button member 330 and membrane 32Ö are inserted into the front housing 310, the larger-diameter portion on the rear of the membrane 320 comes into contact with the ridge 314 inside the front housing 310. This prevents the membrane 320 from moving any further back in the front housing 310 than the ridge 314. In fact, the membrane 320 becomes compressed between the button member 330 and the ridge 314. However, it should be recalled that the membrane 320 is made from silicon rubber and is therefore resilient/flexible. Consequently, even though the membrane 320 is compressed between the button member 330 and the ridge 314, nevertheless the button member 330 can be pressed in (e.g. by a user's finger or thumb) and this causes the membrane 320 to become further compressed between the button member 330 and the ridge 314. When the user removes the pressure on the button member 330, the resilience of the membrane 320 causes the button member 330 to be pushed back out into the position shown in Figure 12. This is therefore how the (non-magnetic) biasing means functions in this embodiment.

[0071] The membrane 320 also performs other functions, in addition to returning (biasing) the button member 330 back to the un-pressed position. For example, the membrane 320 also forms a seal which prevents water, dirt, etc, from penetrating between the button member 330 and the inside of the front housing 310 into the STB unit 300. WO 2014/056021 PCT/AU2013/001135 22 [0072] The plunger coupling 347 is used to couple the plunger rod 340 to the button member 330. Specifically, one end of the plunger coupling 347 (the end which points towards the button member 330) will be glued (or securely connected in some other way) to the rear of the button member 330. The other end of the plunger coupling 347 will be glued (or securely connected in some other way) to the front end of the plunger rod 340. This is how the plunger rod 340 becomes connected to the button member 330. Also, when the plunger rod 340 is thus connected to the button member 330, and when the button member and plunger rod are in the "un-pressed" or un-actuated" position, the round flange portion 341 of the plunger rod (see Figure 13) engages with a portion on or in the back of the front housing 310. This prevents the button member 330 and membrane 320, etc, from falling out of the front of the front housing 310.

[0073] Those skilled in the art will therefore appreciate how the front assembly 400 is assembled.

[0074] Before the STB unit 300 is installed (i.e. before it is mounted on or to the shell/casing of the intercom or other device which the button is to operate), the components of the front assembly 400 will be assembled together, and likewise the components of the rear assembly 410 will be assembled together. However, the front assembly 400 and rear assembly 410 will remain separated from each other for the initial stages of installation of the STB unit 300. In this, the STB unit 300 is similar to the STB unit 1 described above, and in fact the way in which the STB unit 300 is installed is generally the same as described above with reference to Figure 3. This therefore need not be repeated.

[0075] The rear assembly 410 of the STB unit 300 will now be discussed further with reference to Figure 13. Whilst the number and appearance of the components of the rear assembly 410 differs somewhat from the components of the rear assembly 110 of the STB unit 1 in the embodiment described above, the overall function of the components is generally the same.

[0076] For instance, the solenoid housed inside the solenoid housing 360 in Figure 13 performs the same function as the solenoid in the other embodiment described above. The solenoid housing 360 is inserted into the rear of the rear housing 370 (the O-ring 361 is actually inserted ahead of the solenoid housing 360). When the STB unit 300 is fully assembled (i.e. with the front assembly 400 connected to the rear assembly WO 2014/056021 PCT/AU2013/001135 23 410) the magnetic plunger rod 340 inserts through the hole in the centre of the solenoid housing 360 (and hence through the centre of the solenoid) and out the other side to interact with the photo interrupter 302. The function of the solenoid in enabling remote testing of the button is therefore the same as in the other embodiment described above.

[0077] Similarly, the operation of the photo interrupter assembly 302 is generally the same that of the photo interrupter described in the other embodiment above. The photo interrupter assembly 302 includes an infrared sender 322 and an infrared receiver 323. Both are electrically connected to, and powered by, the PCB 380 (although the actual electrical connections are not illustrated). The sender 322 and receiver 323 are physically mounted to the round flat board portion of the photo interrupter assembly 302 which in turn connects to the PCB 380. The sender 322 and receiver 323 are also positioned diametrically opposite each other on either side of the hole 325 (it will be appreciated that the plunger rod 340 inserts through/into the hole 325 when the button is pressed). The sender 322 is operable to send an infrared beam which is received by the receiver 323. Therefore, when the button member 330 and the plunger rod 340 are in an "un-pushed" or "un-actuated" position, the end of the plunger rod 340 does not insert into or through the hole 325 between the sender 322 and receiver 323 and therefore the infrared beam between the sender and receiver is uninterrupted. However, when the button is pushed or moved inwards (either by a user pushing on the button member or by operation of the solenoid-driven self-testing functionality) the plunger rod 340 moves inward such that the end of the plunger rod 340 inserts between the sender 322 and the receiver 323 breaking/interrupting the infrared beam. When the beam is broken/interrupted, the electronics of the STB unit 300 operate to signal that the button has been pushed.

[0078] The spacer 303 performs two main functions. Firstly, it operates as a spacer (i.e. to maintain a gap/space) between the rear of the solenoid housing 360 and the photo interrupter assembly 302. In this regard, the spacer 303 incorporates openings to accommodate, for example, the row of five electrical contacts visible on the PCB 380 in Figure 13, and it also has openings to accommodate the sender 322 and receiver 323 of the photo interrupter, etc. Note that no part of the spacer 303 interrupts the infrared beam sent from the sender 322 to the receiver 323. The other important function of the spacer 303 is to prevent reflections from interfering with the proper operation of the photo interrupter. Specifically, when the plunger rod 340 inserts into the hole 325 between the sender 322 and receiver 323 interrupting the infrared beam WO 2014/056021 PCT/AU2013/001135 24 therebetween, even if the rod causes the infrared beam to be reflected in some way, the spacer 303 is configured such that any reflection is blocked and cannot reach the receiver 323. This ensures that the infrared beam is broken/intenrupted (and no part or reflection of it can reach the receiver) when the plunger rod 340 inserts between the sender and receiver.

[0079] Other aspects of the STB unit 300 illustrated in Figures 12 and 13, and its operation, are generally similar to that of the STB unit 1 described above.

[0080] In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0081] Reference throughout this specification to “one embodiment” or “an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an r embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0082] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims (13)

1. Evc^eiveu .1 üuuih CLAIMS

   1. A button for an electrical device, the button having a button portion which can be physically pressed; a moveable portion which moves from a first position to a second position when the button portion is pressed, and the button portion is connected either directly or indirectly to one end of the movable portion and moves with the movable portion; biasing means operable to bias at least the movable portion to the first position; and remotely operable actuating means operable to move the movable portion from the first position to the second position without the button portion being physically pressed; wherein the button is electrically connected by wiring to the electrical device and causes or allows the electrical device to perform a particular function, or to operate in a particular manner, when the movable portion moves into the second position; the button further including one or more components, including a sender, operable to emit electromagnetic radiation, one or more components, including a receiver, operable to receive at least part of said emitted electromagnetic radiation, and a space between at least the sender and the receiver wherein the sender is operable to send electromagnetic radiation across the space between the sender and the receiver, and the receiver is operable to receive the electromagnetic radiation; and a second end of the movable portion, which is opposite to the end to which the button portion is connected, becomes positioned at least partially in the space between the sender and the receiver when the movable portion is in the second position, whereby, when the moveable portion is in the second position, the second end of the movable portion brakes or interrupts the flow of electromagnetic radiation from the sender to the receiver, whereupon electronics associated with the button signal that the button has been pressed.
2. 2. The button as claimed in claim 1, wherein the biasing means includes a resilient component; one or both of the button portion and the movable portion are at least partly housed within a first housing, and the resilient component extends between the button portion and an inside portion of the first housing, or between the movable portion and the inside portion of the first housing. 3 The button as claimed in claim 2 wherein the resilient component extends between the button portion and the inside portion of the first housing and provides a seal between the button portion and the inside portion of the first housing.
3. 4. The button as claimed in any one of the preceding claims, wherein the movable portion, or part thereof, is magnetic, or there is a movable portion magnet which is connected directly or Indirectly to the movable portion and which moves with the movable portion.
4. 5. The button as claimed in claim 4, wherein the actuating means includes a solenoid and the magnetic field created when an electric current flows through the solenoid interacts with the magnetic field of the movable portion or the movable portion magnet causing the movable portion to move from the first position to the second position.
5. 6. The button as claimed in any one of the preceding claims, wherein the movable portion comprises a unitary elongate component having a principal axis corresponding to its longest dimension, and the direction of the movable portion's movement is parallel to, or collinear with, said principal axis.
6. 7. The button as claimed in any one of the preceding claims, wherein the sender is operable to send an infrared beam across the space between the sender and the receiver, and the receiver is operable to receive the beam, and electronics associated with the button signal that the button has been pressed when the beam is broken or interrupted.
7. 8. The button as claimed in any one of the preceding claims further comprising a reflection blocking component which substantially surrounds the sender and the receiver, but which has an opening or space therein, wherein the opening or space is shaped to receive the sender and the receiver therein but such that no part of the reflection blocking component blocks a direct (unreflected) path of electromagnetic radiation from the sender to the receiver; the opening or space is also shaped to allow the second end of the movable portion to become positioned at least partially in the space between the sender and the receiver when the movable portion is in the second position; such that when the movable portion is in the second position, the second end of the movable portion brakes or interrupts the flow of electromagnetic radiation from the sender to the receiver, but the surrounding reflection blocking component blocks reflected electromagnetic radiation from reaching the receiver while the movable portion is in the second position.
8. 9. The button as claimed in any one of the preceding claims, wherein the button comprises a button assembly, the button assembly includes a front assembly and a rear assembly, and the rear assembly is connected to the front assembly when the button assembly is assembled,
9. 10. The button as claimed in claim 9, wherein the front assembly includes a first housing which has an externally threaded rearward portion, the rear assembly includes a second housing which has an internally threaded forward portion, and the rear assembly and the front assembly are screwed together when the button assembly is assembled.
10. 11. The button as claimed in claim 10, when read as dependent on claims 3,4, 5 and 6, wherein the front assembly includes the first housing, the button portion, the resilient component and the movable component, the first housing has a first through-bore extending from its front end to its rear end, and the inside portion of the first housing with which the resilient component engages is located in, or is part of, the first through-bore, the button portion is received in the front end of the first through-bore, and the resilient component extends between the button portion and the said inside portion of the first housing and provides a seal between the button portion and the first housing, and the movable component is received through the rear end of the first through-bore and a portion of the movable component, including the second end, extends out of the rear end of the first through-bore,
11. 12. The button as claimed in claim 11, wherein the rear assembly includes the second housing, the solenoid and the one or more components which are operable to emit and receive electromagnetic radiation including the sender and receiver, the second housing has a second through-bore extending from its front end to its rear end, the internally threaded forward portion of the second housing is formed in the forward end of the second through-bore, and when the button assembly is assembled: the solenoid is located in the second through-bore, and the one or more components which are operable to emit and receive electromagnetic radiation, including the sender and receiver, are located in the second through-bore.
12. 13. The button as claimed in claim 12, wherein when the rear assembly and the front assembly are screwed together, at least a portion of the first housing’s rear end becomes located inside the second housing’s second through-bore, the portion of the movable component which extends out of the rear end of the first through-bore extends at least partly through the solenoid such that the second end of the movable component is positioned near the sender and receiver, whereby when the movable portion is in the first position, the second end of the movable portion is nearby the sender and receiver but it does not impede the flow of electromagnetic radiation therebetween, and when the movable portion is moved into the second position, the second end of the movable portion brakes or interrupts the flow of electromagnetic radiation.
13. 14. The button as claimed in claim 13, wherein, when the rear assembly and the front assembly are screwed together, at least a portion of the solenoid is received through the first housing’s rear end such that the solenoid is at least partly located within the first housing’s first through-bore, which portion of the first housing is, in turn, located within the second housing’s second through-bore.