AU651459B2 - Movement detector - Google Patents

Description

A P/00/011 Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 5 1 4 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

TO BE COMPLETED BY APPLICANT Name of Applicant: HARRY GREY AND HELEN GREY o *o S" Actual Inventor: HARRY GREY Address for Service: CALLINAN LAWRIE, 278 High Street, Kew, 3101, Victoria, Australia Invention Title: "MOVEMENT DETECTOR" The following statement is a full description of this invention, including the best method of performing it known to us:- 1 1 i -2- This invention relates to movement detectors for alarm systems which may be incorporated in new fences or added to pre-existing fences. More particularly it relates to movement detectors which may detect movement of part of a fence resulting from attempts to scale said fence.

Safety fences around swimming pools have been found to be surmountable by small children who may pile boxes one upon the other to attempt to climb such fences. Such activity may often go undetected and the small child may successfully clamber over the fence. Alarm systems such as those used in microwave or infrared detection systems require detectors and sources to be :10 mounted in appropriate positions. Such detection systems may not be able to r e S provide sufficient coverage to cover the whole of the relevant fence or may require a multiplicity of detectors and/or sources so that the cost is thereby significantly increased. Alarms such as reed switches on gates generally only operate when the gate is opened. Clearly such alarms can be bypassed when the fence is scaleu.

According to the present invention there is provided a movement detection system including at least one hollow member mounted on or in at least one movable or displaceable portion of a barrier, said at least one moveable or displaceable portion of a barrier being pivotally mounted on at least one fixed portion of said barrier, the said at least one hollow member enclosing a filament, said filament at one end being fixed to or otherwise held at corresponding end of one of said at least one hollow member, the other end of said filament being i attached to switch means capable of activating means for emitting a signal, said 7 4 1,

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2a filament being under tension and said switch means being operable by change in tension in said filament when one or more of said at least one movable or displaceable portions is displaced or moved from a preselected orientation or position. The term "barrier" includes fences, gates and walls.

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f 'It, o 5 ft ft f t a ii i -3- Preferably saidr movreahe nrdisplrcpahlp prtfinns are pivntally mrninted nn fiypd portions of said harrier.

Preferably said switching means is operable by increase in tension in said filament, which may be a cable of steel wire.

Preferably the signal emitted when the system is activated is an audible signal. However, the signal could be visual or an electric, electromagnetic or other form of signal transmittable to a receiver in a remote location.

In order that the invention may be more cearly understood, reference is made to preferred embodiments as disclosed in the accompanying non-limiting drawings in which Figure 1 depicts a perspective view of part of a fence incorporating an embodiment of the invention; Figure 2 depicts a sectional view along line 2-2 of Fig 1; Figure 3 a perspective view of the embodiment of Fig 1 showing the movable portion of the fence displaced from its mean position; SFigure 4 depicts a sectional view along line 4-4 of Fig 3; and Figure 5 depicts a perspective view of another embodiment of the €t t Sinvention.

In Figure 1, 10 generally denotes a portion of a fence incorporating the .20 invention, 12 denotes a tiltable or moveable panel of said fence, and 14 denotes a gate in said fence, 16 denotes a length of hollow member fixed to upright bars 18 of moveable panel 12, and 20 denotes a further length of hollow member fixed to upright bars 22 of gate 14. Within hollow members 16 and 20 is disposed a filament 24, preferably a cable of steel wire, which may either be fixed to one end of a hollow member or bear upon said end, or, as depicted, may pass through a i: -4hole 28 in upright post 26 of the fence and thence through hollow members on other movable portions (not shown). The other end of said filament is secured to a switch (not shown here) capablk of activating an alarm signal emitting device.

The filament is under a pre-selected amount of tension. Moveable panel 12 is pivotably mounted on steel or nylon pins 30 set in upright posts 26. When panel 12 is tilted (as in Figure 3) from a pre-selected position or orientation or gate 14 is opened either inwardly or outwardly increased tenaion on the filamenrt caused by said displacement of panel or gate operates said switch which in turn activates a device which emits an audible alarm signal. The hollow members 16 and 20 not only support the filament but also act to prevent the filament being subjected to increased tension by the weight of leaves or birds and thereby accidentally operating said switch and activating the alarm signal emitting device.

Lengths of hollow member can be placed on any number of movable ,I 6°Q panels of a fence and the filament can extend from one section of fence to another 115 so that a single filament may encompass all of the fence including one or more t Sc gates.

The switch means can be any suitable switching means whilst the alarm tt,, system may either be battery-powered or mains-powered with a battery back-up.

One use envisaged for the embodiment shown in Figures 1 to 4 is for fences around in-ground swimming pools. Such an embodiment may be ttt incorporated in a fence during initial fabrication or added later, where circumstances permit.

In Figure 5, the numeral 32 denotes supports for a construction, in this case an above-ground swimming pool, and the numeral 34 denotes outriggers bolted on to said supports. A cage 36 is pivotally mounted (preferably at balance l" i points) on nylon bushes provided on bolts 40 passing through holes 42 in arms 44 of outriggers 34 (shown on one outrigger only) and holes 46 in outer lateral portions 48 of cage 36. A cable 50 passes through nylon bushes in holes 52 in the upper parts of the arms 44 of the outriggers and through a hollow member 54 forming part of the structure of cage 36. The hollow member 54 is also provided with nylon bushes through which the cable also passes. The provision of nylon bushes minimises friction and wear. The cable 50 may pass through a plurality of such arrangements forming a barrier. In a manner similar to that described above in relation to the preceding embodiment the cable is under tension and connected to a switch capable of activating an alarm signal emitting device. Tilting of cage 36 from its normal "at rest", or balance point, position increases tension on the cable leading to operation of the switch and activation of the alarm. Attempts to scale a barrier fitted with such an embodiment by trying to clamber over the cage ~normally will lead to activation of the alarm as the cage generally will be tilted by ~the application of forces to it during the course of such attempts. Such tilting of S the cage will also tend to render the scaling of the barrier more difficult.

It is believed that the invention and many of its attendant advantages 4) a.

will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the embodiments described without departing from the ambit of the invention or sacrificing all its material advantages, the embodiments hereinbefore described being merely preferred embodiments thereof.

Claims (6)

1. A movement detection system including at least one hollow member mounted on or in at least one movable or displaceable portion of a barrier, said at least one moveable or displaceable portion of a barrier being pivotally mounted on at least one fixed portion of said barrier, the said at least one hollow member enclosing a filament, said filament at one end being fixed to or otherwise held at corresponding end of one of said at least one hollow member, the other end of said filament being attached to switch means capable of activating means ttt, S for emitting a signal, said filament being under tension and said switch means tIr !0 being operable by change in tension in said filament when one or more of said at least one movable or displaceable portions is displaced or moved from a *t ttt preselected orientation or position.

2. A movement detection system as claimed in Claim 1 wherein said switching means is operable by increase in tension in said filament.

3. A movement detection system as claimed in either of Claim 1 or Claim 2 wherein the filament is a cable of steel wire.

4. A movement detection system as claimed in any one of Claims 1 to 3 wherein said signal is an audible signal.

A movement detection system as claimed in any one of Claims 1 to 3 substantially as hereinbefore described with reference to either Figure 1 or Figure 2. 'I W -7-

6. A movement detection system as claimed in any one of Claims 1 to 3 substantially as hereinbefore disclosed with reference to Figure DATED this 26th day of May,

1994. HARRY GREY AND HELEN GREY By their Patent Attorneys CALLINAN LAWRIE t St 'Lt t it it S S '555 S iS ii S. II I S S S SIt S ISiS S S Ii IS S I ''55 US I Ii S iS ft ABSTRACT A movement detection system including at least one hollow member (16) mounted on or in at least one movable or displaceable portion (12) of a barrier (10) the least one hollow member (16) enclosing a filament the filament (24) at one end being fixed to or bearing upon corresponding end of one of the at least one hollow member the other end of the filament (24) being attached to switch means capable of activating means for emitting a signal, the filament (24) being under tension and the switch means being operable by change in tension in the filament (24) when one or more of the at least one movable or displaceable portions (12) is displaced or moved from a preselected orientation or position. 0f V. a *40 4* tt t ta t i V t tt