TECHNICAL FIELD

THIS INVENTION relates to a distress alarm system. It relates in particular to a distress alarm system having activation means responsive to properties of sound.

BACKGROUND ART

Alarm systems for household and business use are known in the art. Various mechanisms exist for activating such systems to signal the presence of intruders or to alert others to the existence of an emergency situation of any type. One such mechanism, is the so-called "panic button" or "distress alarm," A panic button is installed at a strategic and conveniently accessible location on a premises. Si Is intended to be depressed manually in the event that an undesirable intruder enters the premises, or in the event of an emergency arising,, whether it be a medical emergency, fire, etc. The conventional panic button is, therefore, a manually operable alarm device as opposed to an alarm device actuated automatically fay the presence of a given trigger condition.

Although panic buttons are usually placed in strategic positions, they may not be easy to reach in hostile or emergency situations, or there may be a delay between the time that an emergency situation arises and the first opportunity to press the button. Also, when an aggressor or intruder is present, any attempts to press a panic button may be seen as aggravating or provocative by the intruder, and a victim may be accordingly be discouraged from trying to press a panic button for fear of a reprisal. There is a need for a system which can address, at least in part, these shortcomings.

DEFINITIONS

For purposes of this specification the term "alarm" is intended to be interpreted widely, it shall not be limited only to audible alarms such as sirens but shall include inaudible signals transmitted to remote locations, for example distress signals transmitted to alarm companies, security companies or rapid response units, requesting assistance or support.

For purposes of this specification, the term "sound" is intended to be interpreted widely. Without limitation, the term shall include reference to all types of sounds, noises, shouts, shots, vocal expressions, percussions, explosions, shocks and blasts, and to all waves, patterns, and signatures and the like associated with these. Related terms, for example, "property of sound", shall have corresponding meanings.

The acronym "PCB" means Printed Circuit Board, and refers to an etched wiring board with a clear image of electronic components.

The acronym "PCBA" means Printed Circuit Board Assembly, and refers to a PCB having components mounted on it.

DISCLOSURE OF THE INVENTION

According to a first aspect of the invention there is provided a distress alarm system which includes connection means for connecting the system to at least one alarm; and sound-triggerable activation means for activating the at least one alarm in response to a predetermined property of sound.

The system typically further includes manually operable activation means for activating the at least one alarm in response to a manual action.

The system typically includes alarm switch means for switching the alarm between a resting condition in which the at least one alarm is inactive, and a working condition in which the at least one alarm is activated. The sound-triggerable activation means may be configured to switch said alarm switch means between said resting condition and said working condition.

The sound-triggerable activation means may include measuring means for measuring a property of the sound, comparing said property against a predetermined threshold condition for said property, and switching the switch means from the resting condition to the working condition based on the outcome of said comparison of the measured property against the predetermined threshold condition.

Without limitation, the predetermined property of sound measured by the sound- triggerable activation means may be selected from the group consisting of sound volume or amplitude, frequency, signature, pattern, and shock wave. Typically, the property of sound which is measured is volume.

The system may include selector means for selecting between a plurality of settings, the system having been preconfigured to take account of different sound environments in which the system may be used, and to adjust the sound-triggerable activation means so that it switches the alarm switch means from the resting to the working condition at different threshold conditions of the predetermined property of sound depending upon the selectable settings of the selector means.

The sound-triggerable activation means may include components selected from the group consisting of a microphone, a receiver, an attenuator (preferably a switchable attenuator), a microfilter, a sound circuit, a printed circuit board assembly, and memory.

The system typically includes a housing within which at least a portion of the manually operable activation means and the sound-triggerable activation means are housed.

Instead, the system may be housed in two or more discrete housings. In such embodiments the manually operable activation means and the sound-triggerable activation means may be mutually spaced from each other and may be housed separately in the discrete housings.

The system may include an onboard power supply. The onboard power supply may be housed within the housing (or within at least one of the housings if there are a plurality thereof), and power supply check means may be provided for checking the state of the power supply.

Generally the distress alarm system described herein is intended to be operated in conjunction with an existing home alarm system, and can either be retrofitted to such a system or can be included as part of the first installation. Existing alarm systems fitted in homes and other buildings typically already integrate a power supply network. In such applications there is less need for an onboard power supply and this may accordingly be omitted from the distress alarm system.

Therefore, instead of (or in addition to) the onboard power supply the distress alarm system provided by the invention may include electrical terminals (e.g. a terminal block)) configured for electrical connection to an external power supply, for example the 12V power supply of an existing home alarm system. In operation, this type of system can draw power directly from the external power supply.

The system may include illumination means for illuminating it in conditions of low visibility so that it may be found more easily by users, for example by users looking for it in the dark or during an emergency situation. The illumination means may include at least one photoluminescent component. The photoluminescent component may form at least a portion of the, or each, housing.

In a further embodiment of the invention, the distress alarm system may include wireless transmission means, for example a WiFi unit, for communicating with a corresponding unit linked to the full alarm system on a property. This frees the distress alarm system up to be placed at a wider selection of locations, i.e. the system does not have to be physically connected to the property's alarm wiring in order to function.

BRIEF DESCRIPTION OF THE DRAWINGS

Selected embodiments of the invention will now be described by way of non-limiting example with reference to the accompanying diagrammatic drawings, in which like reference numerals are used correspondingly throughout to indicate like or similar features.

In the drawings:

Figure 1 shows, schematically, a top perspective view of a distress alarm system according to the invention; Figure 2 shows, schematically, a cross-sectional side view of the distress alarm system shown in Figure 1 ;

Figure 3 shows, schematically, a plan of the distress alarm system shown in Figure 1 ;

Figure 4 shows, schematically, an exploded perspective view of a further embodiment of a distress alarm system according to the invention, this embodiment drawing its power directly from the 12V power supply of a pre-installed alarm system;

Figure 5 shows, schematically, a circuit diagram for the distress alarm system shown in Figure 4;

Figure 6 shows, schematically, a silkscreen for the top side of a PCB to be used in the distress alarm system shown in Figure 4;

Figure 7 shows, schematically, a plan of the assembly of the PCB referred to in Figure 6;

Figure 8 shows, schematically, a silkscreen for the underside of the PCB referred to in Figure 6; and

Figure 9 shows, schematically, a bottom view of the assembly of the PCB referred to in Figure 6.

MODES FOR CARRYING OUT THE INVENTION

Referring to the drawings, reference numeral 10 indicates, generally, a distress alarm system according to the invention. The system 10 has the appearance of a "panic button" unit often found in residential, banking and business settings. However, the system 10 has additional functionality not found in conventional panic button units, as will be seen from the description below. In conventional fashion, the system 10 includes manually operable activation means which consist of a panic button 12 and a button switch 14. In use, the panic button 12 is depressed by a person in distress. The button 12 is mounted such that, in use, it bears upon and acts on the button switch 14, thereby activating an alarm (not shown) to which the system 10 is connected.

Additionally, however, the system 10 has sound-triggerable activation means. In the embodiment of the system 10 shown in the drawings, the sound-triggerable activation means include a microphone 16 connected to a printed circuit board assembly ("PCBA") 18. The PCBA can extend substantially the entire internal length of the system 10.

Alarm switch means are typically provided for turning the alarm on or off in response to signals received from the sound-triggerable activation means. These alarm switch means may be provided by the button switch 14, which may be mounted on the PCBA 18, or the sound-triggerable activation means may have its own separate alarm switch means (not shown) connected to the PCBA 18.

The PCBA 18 typically includes a sound circuit (not shown). This circuit is configured to process incoming signals from the microphone 16 (and other components) and to pass an appropriate signal to the alarm switch means.

The sound-triggerable activation means serve to activate the alarm in response to a predetermined property of sound, e.g. its frequency or volume.

Typically, the property of sound measured is sound volume, i.e. amplitude. Frequency is determined by the selection of the microphone itself.

Microphones of the type used for this application generally have very similar frequency responses. A suitable microphone is available from Panasonic under the brand name Omnidirectional Back Electret Condenser Microphone Cartridge. This type of microphone has a frequency range from 20 to 16,000 Hz.

The predetermined property of sound may be chosen so that a given emergency-related type of sound may thereby be identified by the system 10. The emergency related sound may, for example, be a loud bang, gunshot, scream or other unusual sound typically occurring in association with an emergency. Information relating to the predetermined property of sound may be programmed or hard-wired into the system 10 and/or the sound-triggerable activation means.

The sound-triggerable activation means further includes a microfilter (not shown) which is also mounted on the PCBA 18 and connected to it so that it can process signals passed to it by the microphone 16, and subsequently transmit a processed signal or signals to the sound circuit. The microfilter serves to limit unnecessary alarm triggers, for example triggers caused by a truck driving by or a dog barking in the vicinity of the system 10.

The sound-triggerable activation means further includes selector means in the form of a three-way, slideable selector switch 20, which may be operated by a user. In the embodiment shown, the selector switch 20 has three separate settings which are preconfigured to adjust the sensitivity of the sound-triggerable activation means for three different ambient sound environments.

For example, a low setting (less filtering or attenuation) may be provided for selection and use in generally quiet environments such as libraries, banks and homes for senior citizens. A medium setting is provided for use in locations such as private homes, schools, busy shops and workshops. The highest setting (most filtering) is reserved for environments such as nightclubs, parties and other loud gatherings but is preconfigured to be sensitive enough so that it can still be set off by gunshots or similar sounds, and thereby trigger the alarm.

The selector switch 20 is, in effect, a switchable volume control.

The system 10 further includes an onboard power supply 22. Typically the power supply 22 includes two watch batteries or button cells such as are known in the art. Power is only needed to send pulse to trigger the alarm, and accordingly it is expected that the batteries or cells will provide extended service before needing to be replaced.

For purposes of checking the charge status of the power supply 22, a power check switch 24 is provided. This works hand-in-hand with a power supply status indicator 26 (typically a light emitting diode or "LED" indicator). The LED indicator 26 lights up when the power check switch 24 is depressed, if the power supply 22 is charged.

In preferred embodiments, all the components of the distress alarm system 10 are mounted inside a single housing 28, forming a single integrated unit which can easily be installed (i.e. retrofitted) as a replacement for an existing panic button unit of conventional construction. In certain circumstances the conventional unit (not shown) can be swopped out by disconnecting two wires (not shown) which are then reconnected to the replacement system 10.

It will be appreciated that other embodiments of the system (not shown) are feasible. For example, the manually operable activation means may be mounted in a first housing and the sound-triggerable activation means may be mounted in a second housing spaced from said first housing. Typically, though not necessarily, such separate first and second housings would, in use, be placed in proximity to one another (for example in the same room).

The housing 28 typically has a microphone grille 30 defined through it. Mounting holes 32 are also defined through the housing 28, into which fasteners (not shown) such as screws or the like may be inserted, for use when mounting the system 10 onto a substrate such as a wall, panel or other supporting structure. Instead, the system 10 can be mounted by means of double-sided ("two-way") tape.

By comparison with conventional distress alarm units (panic button units), the size and shape of the system 10 will typically be increased by two to three millimeters in at least one dimension, to accommodate the additional components and circuitry described above. Apart from these differences the main visible difference compared with conventional units is the presence of the microphone grille 30.

In use, the system 10 is mounted in a location where it may be strategically accessible in the event of an emergency. Advantageously, the system 10 is substituted for an existing panic button unit and connected to an existing alarm system. The selector switch 20 is set to whichever one of its three settings is appropriate for the sound environment in which the system 10 is located (low setting for quietest environments). The power check switch 24 is then depressed to check whether the onboard power supply 22 is in a charged (i.e. good) state. If it is, the LED indicator 26 lights up to confirm this status. The system 10 is then left in place. In the event of an emergency arising, the system 10 can activate the alarm by either of two separate mechanisms. Firstly, in conventional fashion a person can activate the alarm by pressing the panic button 12, which then acts upon the button switch 14 and triggers the alarm. Instead, or in addition, the alarm will be triggered by a loud noise unusual for such environments. For example, the alarm could be triggered by an unusual sound event such as a loud bang, explosion, gunshot or scream. The sound of the unusual event penetrates the housing 28 via the microphone grille 30 and is received by the microphone 16. Signals from the microphone 16 are filtered by the microfilter (not shown) and processed by the sound circuit (not shown), which may be integrated into, or connected to, the PCBA 18. The system 10 has been preconfigured during manufacture with a number of preset threshold conditions for a given property of sound, at which triggering of the alarm will occur, depending on the setting of the selector switch 20. The sound circuit, acting with reference to the setting of the selector switch 20, makes a decision on whether to send pulse to the alarm switch means and thereby trigger the alarm. If a predetermined threshold condition is met, the alarm is automatically triggered by the system 10 without the need for pressing of the panic button 12.

Referring now to Figures 4 to 9, a further embodiment 110 of a distress alarm system is shown. In this case the system is not battery-powered but instead draws its power from an external power supply (not shown).

The system 110 shown in Figure 4 has components which are similar to those of the system 10 shown Figures 1 to 3, but differs primarily in that no onboard power supply is present. Rather, the system 110 is designed to be connected to the 12V power supply of an alarm system already installed in a building.

A terminal block 34 is provided, inter alia, for purposes of drawing power from the alarm system and for connecting the system 110 to the alarm so that the latter may be activated when required. In Figure 5, reference numeral 112 indicates, generally, a circuit diagram for the distress alarm system 110.

In Figure 6, reference numeral 114 indicates, generally, a silkscreen for the top side of the PCB used in the system 110.

In Figure 7, reference numeral 116 indicates, generally, a plan of the PCBA 18 of the system 110, showing the location of components in the assembly.

In Figure 8, reference numeral 118 indicates, generally, a silkscreen for the underside of the PCB used in the system 110.

In Figure 9, reference numeral 120 indicates, generally, a bottom view of the PCBA 18 of the system 110, showing the location of components in the assembly.

The components referred to in the circuit diagram 112 are described further in Table 1 hereunder. This table also sets out the footprints of the components on the PCBA 18, as shown in Figures 6 to 9.

During operation of the system 110, sound is picked up by microphone MK1 and fed via a switchable attenuator to the base of transistor Q1. The output of the transistor is rectified and fed to a switching transistor Q2. When the sound level reaches a certain threshold, determined by setting of the switch, Q2 will switch on and activate a relay, K1 which in turn operates an external device, alarm or siren. The external device may be configured to transmit a signal to an alarm company, rapid response unit or the like. The signal which is activated may be inaudible. Instead or in addition, an audible alarm may also be activated.

The push switch (the component SW1 corresponding to the button switch 14) serves to test the device or siren, and/or to operate it manually.

In a further embodiment of the invention (not shown in the drawings) the distress alarm system includes wireless transmission means, for example a WiFi unit or a radio transponder, so that the housing of the system (containing the panic button) can be placed at a location spaced away from the existing wiring of the full alarm system on a property. This, in turn, frees up the decision on placement of the panic button so that it can be installed wherever is most convenient for access in emergency situations.

The distress alarm system described herein may have advantages over conventional distress alarms and panic buttons. The original functionality of the panic button is retained. However, with the system herein described there is additional functionality because the alarm may be triggered from a reasonable distance without the need to push a button. A loud scream or bang may trigger the alarm, provided the sound- triggerable activation means are preconfigured and an appropriate setting of the The system described herein can be installed in combination with an existing alarm system as it is a stand-alone unit and does not need to be integrated into alarm circuitry in any complex way. Installation is therefore reasonably easy, and in some cases installation is as simple as disconnecting wires from an existing panic button unit, reconnecting the same wires to the system described herein, and mounting said system on a wall with fasteners or double-sided tape.