SECURITY APPARATUS

Abstract: Security apparatus for protecting valuable objects on display, for example vases (2), statues, sculptures and the like. A support structure (1) on which to place the object for display is provided with a duct (3) having an open end (4) positioned so as to be covered by the object (2) when it is placed on the support stucture (1) for display. The other end of the duct communicates with a closed space (6) forming part of a chamber (10) closed by the object (2) on display. The chamber (10) is held at non-atmospheric pressure, preferably sub-atmospheric pressure, and an alarm (14) is responsive to a change of that pressure in the chamber.

Description: SECURITY APPARATUS TECHNICAL FIELD This invention relates to security apparatus for protecting valuable objects on display, for example works of art displayed in museums, galleries and the like. Art objects such as vases, statues, sculptures, bowls and the like are often on " open display in museums and galleries and are only protected against theft by general security of the whole display area. The present invention enables such objects to be secured in an inexpensive but most effective manner. DISCLOSURE OF INVENTION According to the invention there is provided security apparatus for securing an object for display, comprising:- a support structure on which to place the object for display and provided with a duct having an open end positioned so as to be covered by the object when it is placed on the support structure for display; means to close the other end of the duct to create a closed chamber; means enabling the chamber to be held at non-atmospheric pressure; and alarm means responsive to a change of pressure in the chamber to produce an alarm signal. Preferably the means to enable the chamber to be held at non-atmospheric pressure is such as to enable it to be held at sub-atmospheric pressure. The chamber may comprise the interior of the duct and any space enclosed between said object and the support structure in the closure of the first said end of the duct. The means to close the other end of the duct may comprise a structure having a hollow interior space connected with the interior of the duct at the closure of the other end of the duct and forming part of the air chamber. That structure may incorporate a flexible diaphragm movable on change of pressure within the chamber and the alarm means may be responsive to such movement of the diaphragm. The alarm means may emit an audible alarm signal or a radio signal. BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully explained one particular embodiment will be described in some detail with reference to the accompanying drawings, in which: Figure 1 is diagra matically illustrates a vase displayed on a stand incorporating a security apparatus in accordance with the invention; and Figure 2.shows the security apparatus in an alarm condition arising from removal of the vase from the stand. BEST MODE OF CARRYING OUT THE INVENTION The illustrated stand comprises a support structure in the form of a platform 1 and the vase 2 is placed upon that platform. A tubular duct 3 extends transversely through the platform 1. Duct 3 has an open end 4 which is covered by the base of the vase 2. The underside of the vase base is concave so that a space 5 is formed between the vase and platform 1 in the closure of the end 4 of duct 3. The other end of duct 3 communicates with an air space 6 defined by the interior of a hollow cylindrical structure 7 forming part of an alarm control unit 8 fastened to the underside of platform 1. Tubular structure 7 is closed at its bottom end by a flexible diaphragm 9. The interior space 6 of the tubular structure 7, the interior of duct 3 and the space 5 between the vase and platform 1 together form a continuous chamber 10. Alarm control unit 8 has an outer casing 11 provided with a suction fitting 20 incorporating a non-return valve. This enables the interior of the casing to be evacuated to sub-atmospheric pressure. The air in chamber 10 can then expand by movement of diaphragm 9 so th3t chamber 10 is also reduced to sub-atmospheric pressure, albeit to a lesser degree than the interior of the casing. The casing of control unit 8 houses an electrical switch 12 having an actuator 13 engaged wi h diaphragm 9 so that the switch is actuated by movement of the diaphragm. The switch is wired to an alarm 14 powered by a rechargeable electric battery 15. The alarm may comprise a radio transmitter to emit a radio signal to a central security station. Alternatively or in addition it may comprise a simple sound alarm which on activation emits an audible alarm signal. 5 The rim 16 of the vase base may be adhered to platform 1 with a suitable adhesive to ensure adequate sealing of chamber 10. Air is then pumped from the interior of the control unit casing to create a partial vacuum within the control unit casing. The fixed volume of air within chamber 10 10 then expands moving the diaphragm to the condition shown in Figure 1 in which it holds switch 12 in an active or "on" condition. Thus there is created two chambers at differing sub-atmospheric pressures separated by the diaphragm 9. Removal of the vase will break the seal of chamber 15 10 exposing it to atmospheric pressure. This will cause movement of the diaphragm to the condition illustrated in Figure 2, so causing switch 12 to activate the alarm. Admission of air into the control unit casing will cause movement of the diaphragm in the reverse direction. The 20 switch may be arranged so th.at this reverse movement will also activate the alarm. The interior of the casing may be brought to atmospheric pressure by manipulation of an air inlet tap 17 to enable resetting of the diaphragm when the vase is removed and replaced. The air inlet tap may be associated with a 25 locking mechanism effective to de-activate the alarm before operation of the air inlet tap and to ensure the alarm cannot be bypassed by operation of the tap. The illustrated apparatus has been advanced by way of example only and it could be modified considerably. For 30 example it is not necessary that a protected object should define an air cavity at the position where it closes the duct. For the protection of objects with a flat bottom face, the duct may be enlarged to provide more volume, either throughout its length or at its upper end. The chamber to be evacuated 35 could in fact be formed entirely within the support structure for the vase. Moreover this chamber could be evacuated by direct application of suction through a suction fitting rather than indirectly by applying a suction pressure to the outside of the diaphragm. INDUSTRIAL APPLICABILITY The invention enables provision of a simple and concealed means for individually securing many kinds of art object when displayed on a stand or other support.

Claims: THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. Security apparatus for securing an object for display, comprising a support structure on which to place the object for display and provided with a duct having an open end positioned so as to be covered by the object when it is placed on the support structure for display; means to close the other end of the duct to create a closed chamber; means enabling the chamber to be held at non-atmospheric pressure; and alarm means responsive to a change of pressure in the chamber to produce an alarm signal. 2. . Security apparatus as claimed in Claim 1, wherein the means to enable the chamber to be held at non-atmospheric • pressure is such as to enable it to be held at sub-atmospheric pressure. ' 3. ' Security apparatus as claimed in Claim 1 or Claim 2, wherein the chamber is comprised of the interior of the duct and any space enclosed between said object and the support structure in the closure of the first said end of the duct. 4. Security apparatus as claimed in any one of the preceding claims, wherein the means to close the other end of the duct comprises a structure having a hollow interior space connected with the interior of the duct at the closure of the other end of the duct and forming part of the air chamber. 5. Security apparatus as claimed in Claim 4, wherein the structure having the hollow interior space incorporates a flexible diaphragm movable on change of pressure within the chamber and the alarm means is responsive to such movement of the diaphragm. 6. Security apparatus as claimed in Claim 5, wherein the means enabling the chamber to be held at non-atmospheric pressure comprises means defining a second chamber to which the diaphragm is exposed at its side opposite the first said chamber and means to ev3CU3te the second chamber to sub-atmospheric pressure so as to cause expansion of the first said chamber by movement of the diaphragm. 7. Security, apparatus as claimed in Claim 6, wherein the means defining the second chamber is comprised of a casing surrounding the structure having the hollow interior space and the means to evacuate the second chamber comprises a suction fitting in said casing. 8. Security apparatus as claimed in Claim 7, wherein the casing is also provided with an air inlet tap to allow the second chamber to be brought to atmospheric pressure for initial setting of the diaphragm. 9. Security apparatus substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: MILLAR FREDERICK WILLIAM, MILLAR, FREDERICK, WILLIAM
Applicants: MILLAR FREDERICK W, MILLAR, FREDERICK, WILLIAM
Application year: 1986
Main classification: G08B13
IPC codes: G08B13