GB2453178A

GB2453178A - Separation alarm for monitoring children with separate monitor unit and guardian alarm

Info

Publication number: GB2453178A
Application number: GB0719087A
Authority: GB
Inventors: Charles Alvin Scott; Angela Rose Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-09-29
Filing date: 2007-09-29
Publication date: 2009-04-01
Anticipated expiration: 2027-09-29
Also published as: GB2453178B; GB0719087D0

Abstract

An alarm system for monitoring the location of one or more children comprises an adult unit (11, A) , one or more child units (12, C) and a master unit (10, M). The master unit and child units use the received strength of transmitted radio signals to determine the separation distance, with either the child or master units transmitting a carrier signal. Preferably the master unit transmits a query signal and receives a reply from the child units. Preferably both the child and adult units are carried on wrist straps by the monitored child and their guardian respectively; the master unit can either be placed at a static location (fig 2) on a base unit (13 fig 4) or is mountable on the adult unit (fig 5). The master unit can communicate an alarm signal to both the adult and child units. The child unit 12 has a locking mechanism which can only be released on entry of a code or PIN or a signal from the adult unit. A first warning may be triggered at a first separation, with an alarm warning triggered at a greater separation.

Description

Child Safety Device This invention relates to improvements in child safety devices.

Due to persistent public anxiety arising from frequent reports of the abduction of young children, as well as parental concern over much more frequent, but less reported, instances of children losing contact with parents or other carers, a large number of proposals have been made for alarm devices to alert carers when children disappear' that is stray beyond a safe distance where they can be monitored by direct visual and audible contact.

Such devices usually comprise a unit to be carried or worn by the or each child, and a monitor unit to be carried by the guardian. The units are in touch by means for radio frequency signals, and the child unit is usually programmed to respond to interrogating signals from the monitor unit, andlor to emit an alarm signal when removal is attempted, or operated by the child. The adult unit is usually arranged to go into alarm mode when an interrogating signal is not replied to, or if an alarm signal is received from the child unit. The interrogating signals may be sent automatically by the monitor unit at frequent intervals, or on activation by the guardian. With many such systems it is possible to set a variable distance beyond which the alarm will be triggered, the distance usually being changed depending on circumstances, for example the distance at which the child can still be kept in sight.

This may be relatively long in open park areas, but need to be reduced to a tighter perimeter in crowded or restricted locations such as streets or shopping malls.

Some locations such as a house, house-and-garden, or playground may however have a fixed safe area, but both the adult and child desire to move around in that area, for play or housework. In this situation, where the adult unit is carried by say a mother working in a rear kitchen, and the child moves to a front room, or the mother goes into the garden to hang or take in washing, the distance may be exceeded and the adult unit will loose' the child unit, so that an alarm is triggered needlessly.

On the other hand, if the adult unit is left at a more central location, the mother could well not be within audible range of an alarm if the child were to go out of range, by for example wandering out of a front door or garden gate.

It is an object of the invention to provide a child safety device whereby both the child may be free to move about within a predesignated safe area whilst at the same time allowing the guardian to monitor the safe area from within or without the area, but which is also adaptable for use inside buildings, or in open spaces outside, where there is no predefined safe area.

According to the invention, a child safety device comprises at least one child unit, adapted to be carried by for example a child, and at least one adult unit, and further including a master unit, the master unit being adapted to monitor the range of the or each child unit, and communicate with the adult unit, to transmit data including any alarm state thereto.

The master unit is preferably adapted to be physically connectable to and separable from the adult unit to be portable with the adult unit, or left in a stationary location while the guardian carries the adult unit with himlher self.

Both the adult and child units may be mounted on wrist straps to be worn on the lower arm of the guardian and the or each child. The adult unit strap may be a conventional watch strap buckle, whereas the child unit may have a special locking device which may be arranged only to be released on entry of a code or pin number, or a signal from the master unit.

The master unit is preferably a coded radio transmitter/receiver warning and alarm device which is adapted to communicate by radio frequency to the child unit and the adult unit. Recognition may be by the transmission and reception of coded digital "words" of a length suitable to make random generation of such a signal statistically extremely unlikely. The master unit may be adapted to sense the strength of a carrier signal from the child unit, to determine the distance of the child unit, and if the determined distance approaches a specified safe distance send a first level warning signal to the child and adult units. If the determined distance exceeds the specified safe distance, then the master unit may be adapted to transmit a higher level alarm signal to the child and adult units.

Alternatively, the child unit(s) may receive a carrier ranging signal from the master unit, and emit a warning or an alarm signal depending on whether the attenuation of the ranging signal indicates that the child unit is approaching or has exceeded the specified safe distance respectively. The master unit would then relay the warning or alarm signal to the adult unit.

The child unit, and adult unit may emit suitable warning and alarm signals, such as an audible or visual or vibratory signal, or a combination of all three.

A separate base unit may be provided for the master unit when used detached from the adult unit. This may include a power source such as a battery or mains connections.

The range is preferably set by control of the master unit, and may be entered by using a numerical key pad, or selected from a menu of possible ranges.

The transmitter in the master unit may be adjustable to vary the strength of the carrier signal so that the child unit will respond when the received strength of the signal has reduced to a first (higher) threshold level, to cause a warning signal to be triggered, and then to a second (lower) threshold level to cause an alarm signal to be triggered.

The child unit may be set up to emit these signals when the thresholds are reached.

Alternatively, the signal strength of response signals from the child unit to a regularly emitted query signal from the master unit may be measured and determine whether the master unit should send a warning or alarm signal to the child unit and adult unit.

The locking device for the child unit strap may comprise a pair of fixed pins within a housing forming an end part of the child unit shell, these provide a single position connection for a pair of holes in the free end of the wrist strap. The housing may have a lid which is only unlockable by a signal from the master unit to lift the lid up and disengage the strap from the pins.

The master unit may have locating pins or other detents which enable it to nest with the base unit, and on the adult unit.

The master unit is preferably provided with a key or button pad for input of instructions and the master unit, adult unit, and child units may each be provided with appropriate audible or visual signal devices, andlor a vibrator, to signal a warning or alarm state.

An embodiment of child safety device according to the invention will now be described by way of example, with reference to the accompanying drawings, wherein: Figure 1 diagrammatically illustrates the functional relationship of the components of the device; 0 -5-Figure 2 shows a hypothetical use situation in an area with a known safe boundary; Figure 3 is a perspective sketch of a child unit of the device, showing the wrist strap disengaged; Figure 4 shows a monitor unit and a base unit and how the master unit seats into the base unit; and Figure 5 shows an adult unit with wrist strap and showing how the master unit seats onto the adult unit.

A child safety device according to the invention consists of three parts -a master unit 10, an adult unit 11, and one or more child units 12.

The master unit 10 provides a portable device which can be used in conjunction with the adult unit 11 or separated from it and joined instead to a base unit 13 holder.

The master unit 10 acts to monitor the distance of the or each child unit 12 from the master unit. This is done by emitting query signals at regular frequent intervals which are answered by the child unit, and the master unit may measure the signal strength to determine the degree of attenuation of the return signal to determine the distance of the child unit.

If the strength falls below a first higher threshold, then the unit will determine that a preset safe distance is being approached, and send a warning signal to the child unit 12 and to the adult unit 11. The warning signal will trigger a warning device in both the adult and child units which may take the form of vibration of a vibrator and flashing red diode or other visual indicator in each unit. This warning signal may be cancelled by the child returning over the threshold distance, or by the child pressing a cancelling switch.

If the return signal strength falls below a second lower threshold, then the master unit 10 will determine that the preset safe distance has been too closely approached, e.g. within 1-1.5 metres, and will trigger audible alarm devices in each of the child unit 1 2 and the adult unit 11 and cause more intense vibration of the vibrator in each unit. This will warn both the child and an adult guardian that the child has strayed. The child alarm may be chosen to be such as to warn off an attempted abductor. At the same time a responsible adult is alerted arid may proceed to take action to recover the child. It will be noted that other factors such as intervening walls may cause attenuation, but as these may indicate straying beyond a safe area, the alarm should still be raised. The alarm mode may only be cancelled by return of the child unit to the immediate site of the adult unit and only then by use of a pin code in the adult unit or by a physical link.

Figure 2 illustrates a situation where the master unit 12 might be located away from an adult. The figure shows the plan of a house and garden area. The adult A, with the adult unit 12 on her wrist is reading or watching television in the front room 20, whilst the child C is playing in the rear garden 21. The master unit M is placed on a work surface or the like in the dining room 22. The safe distance is set at the range of the rear fence of the garden. The child will be in range so long as he is within the garden, but might escape by wandering out of the rear gate 23, or down the side passage 24, to the front garden 25 and wander out of the front gate 25. If he does so however, the master unit M will detect that the child unit is no longer within range, and signal an alarm.

When walking abroad with children in attendance, the adult guardian will place the master unit 10 on the adult unit 11 as in Figure 3. The distance may be set by using the key pad 14 of the master unit to select from a menu or by inputting appropriate numbers and will accord with the distance felt to be appropriate for the conditions -sight lines and crowdedness for example.

Additional functions may be provided, e.g. a call button on the master unit may be activated to send a query signal if the adult loses sight of the child, so that the child can try to make its way back. A directional facility may be provided so that the master imit can direct the adult towards the child.

Figure 3 shows that the child unit 12 is mounted on a strap 16, which has a pair of holes 17 defined by eyelets in its free end which engage on two studs 18 in a housing 19 in the unit casing which can only be opened to release the strap on a code signal transmitted from the master unit. This serves to hinder an attempt to remove the child unit by an abductor. The strap may contain reinforcement wires of stainless steel attached to the eyelets, or be of cut resistant material.

Adjustment for fit may be by means of a plurality of pairs of eyelets in the other end of the strap, cooperating with a pair of pins on a slidable tray in the unit housing. A plurality of straps of different sizes may be offered for use with wrists of different girths.

When used as in Figure 2, the master unit 10 is mounted on a base unit 13, which has apertures 30 to receive detents 31 on the underside of the unit 10. Base unit 13 may include a power source such as a battery andlor be connectable for mains operation.

The base unit 13 may be adaptable to function as a recharging unit for the batteries of the other units of the device.

Figure 5 shows the master unit 10 in association with the adult unit 11 which is carried on a wrist strap 32 with an ordinary buckle fastening. An expanding strap could of course be used instead. As with the base unit, the detents 31 of the master unit 10 are received in apertures 33 in the upper face of the adult unit II.

The adult and child units 11, 12 are provided with visual and audible signalling devices, and also vibrating devices, for giving the warning and alarm signals. Both the adult and child units may be equipped with emergency signal buttons to contact the master unit. Only the master unit 10 has a key pad 14 for inputting data such as selected distances.

A passive monitoring device may be built in to operate in a fixed perimeter such as a play school or school. Each child would wear a child unit of the type described, and some or all staff an adult unit. The operation would be similar to as 1 5 described with reference to Figure 2 above.

Claims

Claims.

1. A child safety device comprising at least one child unit, adapted to be carried by a child, and at least one adult unit, and further a master unit being adapted to monitor the range of the or each child unit, and communicate with the adult unit, to transmit data including any alarm state thereto.

2. A device according to claim 1 wherein the master unit is adapted to be physically connectable to and seperable from the adult unit to be portable with adult unit, or left in a stationary location.

3. A device according to claim 1 or 2 wherein both the adult unit and child unit(s) are mounted on wrist straps to be worn on the lower arm of the guardian, and the or each child.

* *

4. A device acccording to claim]. and 3 wherein the adult unit is provided with a key, button or touch pad to facilitate entering a code or PIN to control the locking, unlocking, and adjustment mechanism of the child unit strap and the reset' of the alarm activation. * S S

S *.S

5. A device according to claim 1 3 and 4 wherein the adult unit is mounted on a conventional buckle type wrist strap and allows the adult to monitor the child unit from within the set safe area or from some distance outside the .: set safe area, either in static or mobile use.

6. A device according to claim 1 and 3 wherein the child unit strap has a locking mechanism which is arranged only to be operated on entry of a code or PIN into the adult unit and only when both units are in close proximity, the preferred embodiment having a short cable and jack plug connection.

7. A device according to any preceding claim wherein the master unit comprises a coded radio transmitter/receiver warning and alarm device which is adapted to communicate by radio frequency to the child unit(s) and adult unit.

8. A device according to claim 7 wherein the master unit is adapted to transmit and receive coded digital words' of a length suitable to make random generation of an identical signal statistically extremely unlikely.

9. A device according to claim 7 or 8 wherein the master unit is adapted to sense the strength of a carrier signal from the child unit to determine the distance of the child unit, and if the thus determined distances approaches a specified safe distance limit, to send a first level warning signal to both the child and adult units.

10. A device according to claim 7 8 and 9 wherein the master unit is further adapted to transmit a higher level alarm signal to the adult unit and child unit(s) if the determined distance exceeds the specified safe distance.

11. A device according to claim 7 wherein the master unit is further adapted to emit a carrier signal to the child * * unit and the child unit is adapted to emit a warning or an . alarm signal if the attenuation of the carrier wave indicates that the child unit is approaching or has *.. exceeded the specified safe distance. 4I* * . , 4 0

*:.

12. A device according to any preceding claim wherein the child unit, adult unit and master unit are adapted to emit * suitable audible, visual or vibratory warning and alarm signals, or a combination of any two or all thereof. 4S 4 * * . * 04

13. A device according to claim 2 and 7 wherein a seperate base unit is provided for the master unit to be mounted upon, when the master unit is detached from the adult unit for static use.

14. A device according to claim 7 wherein the master unit is provided with a key, button or touch pad for control of specified distance settings, which may be variable or by selection from a menu of possible ranges.

15. A device according to claim 7 and 14 wherein the transmitter of the master unit is adjustable to vary the strength of the carrier signal so that the child unit will respond when the received strength of the signal has reduced to a first (higher) threshold level to cause a warning signal to be triggered and then a second (lower) threshold level to cause an alarm signal to be triggered.

16. A device according to claim 7 14 and 15 wherein the signal strength of response signals from the child unit to a regularly emitted query signal from the master unit, is measured to determine if the master unit should send a warning or alarm signal to the child unit(s) or adult unit.

17. A device according to claim 6 wherein the locking mechanism for the child unit strap comprises a pair of fixed pins set in a slidable metal tray within the base of the child unit case, which will provide a single position connection for a pair of eyelets in the free end of the * ,. wrist strap. IS * * I. *.. * . *S.

18. A device according to claim 6 and 17 wherein the fixed :. end of the child unit strap provides a level of adjustment by a series of pairs of eyelets, to locate on a further fixed pair of pins set in the slidable metal tray, within the base of the child unit case. I... ** * * **

* "

19. A device according to claim 6 17 and 18 wherein the said child unit wrist strap is made from a flexible material reinforced with stainless steel wire mesh, being securely attached to the pairs of metal eyelets at each end of the strap, and may be used to provide anti-tamper circuitry.

20. A device according to claim 6 17 18 and 19 wherein the child unit housing has a lid to facilitate the wrist strap being adjusted, locked and unlocked, and being controlled solely by the adult unit, by entry of a code or PIN and using the preferred embodiment of a short cable and jack plug connection.

21. A device according to claim 1 2 7 and subsequent claims wherein the master unit has locking pins or other detents which enable it to be attached to the adult unit for mobile use or attached to the base unit according to claim 13 for static use.

22. A device according to claim 1 and subsequent claims wherein the master unit, the adult unit and the child unit are each provided with appropriate audible, visual and vibratory devices to indicate to the adult and child wearers that a warning and/or alarm situation has been reached, it is also the intention that the audible and visual devices will raise the awareness of an alarm situation with the public.

23. A device according to claim 1 and subsequent claims wherein the child unit, the adult unit and the master unit are constructed in such a manner and of such materials as to make them water-proof and shock-resistant. * **

24. A device according to claim 1 and subsequent claims *. wherein the child unit, the adult unit and the master unit are each powered by rechargeable batteries and may have a solar panel and an eco-drive to extend battery use time and : each unit will also be provided with a means of recharging via the mains electricity. ****

*..:

25. A device according to claim 1 wherein the child unit *. : may have a passive device' in-built to operate in a fixed * perimeter security system, as in a nursery, play group or primary school application.