SECURITY APPARATUS

Abstract: Security apparatus for protecting framed art works such as paintings, etchings, prints and the like (11). A tubular element (13) is extended around the frame (12) behind the art work. The interior of the tubular element is held at non-atmospheric pressure, preferably sub-atmospheric pressure, and an alarm is responsive to a change in that pressure to cause an alarm signal. The tubular element (13) has a perforated surface which is adhered to and sealed against the back of the art work to be protected so that the seal will be broken if the tube is dislodged. The tubular element (13) may have an extension for attachment to a wall when the art work (11) is hung from that wall such that removal of the art work from the wall will also cause a change of pressure within the tubular element (13).

Description: SECURITY APPARATUS TECHNICAL FIELD This invention relates to security apparatus for protecting valuable art works. It has particular application to the protection of valuable paintings, etchings, prints and similar art works on display to the general public. Conventional security equipment is generally directed to providing at the location in which the art works are displayed whether it be a private collection or an art gallery displaying the works for public view. Paintings and like works, when. stolen, are frequently cut from the surrounding frame so allowing it to be rolled up and more readily carried away from the premises. In some cases, however, the complete framed work may be lifted away from the wall on which it is hung and carried away in its entirety. The present invention provides a quite inexpensive and unobtrusive means whereby works of art can be individually secured against theft. DISCLOSURE OF INVENTION According to the invention there is provided security apparatus for the protection of a framed art work, comprising:- a tubular element to extend, in use of the apparatus, around the frame behind the art work; means enabling the interior of the tubular element to be held at non-atmospheric pressure; and alarm means responsive to a change in pressure in the tubular element to cause an alarm signal. Preferably the means enabling the interior of the tubular element to be held at non-atmospheric pressure is such as to enable evacuation of that element to sub-atmospheric pressure. The tubular element may have a perforated surface which in use of the apparatus is adhered to and sealed against the back of the art work to be protected. The tubular element may comprise a length of tubing and it may have at least one extension for attachment to a wall when the framed art work to be protected is hung from that wall such that removal of the framed art work from the wall will cause loss of vacuum pressure in the tubing. Such extension may have an open end and in use of the apparatus the open end may be adhered to and sealed against the wall. The means to enable the interior of the tubular element to be held at non-atmospheric pressure may comprise a chamber for connection with the interior of the tubing and a vacuum connection to the chamber through which to evacuate the chamber and the interior of the tubing to sub-atmospheric pressure. The alarm means may then be responsive to a change of pressure in said chamber. More specifically the chamber may be closed by a diaphragm or other element movable in response to pressure change within the chamber and the alarm means may be activated by movement of the diaphragm or other element. The alarm means may comprise a switch activated sonic alarm or radio transmitter. The chamber and the alarm means may be contained in a housing which in use of the apparatus is mounted on the back of the art work. BRIEF DESCRIPTION OF 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 a rear view of a framed painting fitted with a security apparatus in accordance with the present invention; Figure 2 is a side view of the framed painting when hung from a wall; Figure 3 is a perspective view of a length of tubing incorporated in the security apparatus; Figure 4 is a transverse cross-section through the tubing shown in Figure 3; Figure 5 illustrates a control unit mounted on the back of the painting and forming part of the security apparatus; and Figure 6 illustrates a -modified form of control unit which may be incorporated in place of that shown in Figure 5. BEST MODE OF CARRYING OUT THE INVENTION The drawings show a painting 11 mounted in a rectangular frame 12, a tubular element 13 is applied to the back of the painting so as to extend around the inner periphery of frame -12. Tubular element 13 is formed of flexible tubing. It has a rectangular portion . 14 to match the inner periphery of the frame and a central cross tube portion 15. The tubing of element 13 has a flattened cross-section so as to define a flat face 16 to be applied against the back of the painting. This flat face has longitudinally spaced transverse slots 17 and on installation of the security apparatus it is adhered to and sealed against the back of the painting. The tubing is also formed with longitudinally extending interior ribs 18 to prevent it from collapsing. The security apparatus also comprises a control unit denoted generally as 21 mounted on the back of the painting immediately within one of the bottom corners of the tubular element 13. The control unit comprises a casing 22 the interior of which is divided into two chambers 23, 24 by a flexible diaphragm 25. Chamber 23 is connected to the interior of tubular element 13 via a tubular connector nib 26 which perforates the wall of the tubular element. A suction connector 27 provided with a non-return valve is mounted in the wall of casing 22 to communicate with chamber 24. Suction applied through this connector enables evacuation of chamber 24 to sub-atmospheric pressure. The air in chamber 23 and the interior tubular element 13 can then expand by movement of diaphragm 25 so that chamber 23 and the interior of the • tubular element are also reduced to sub-atmospheric pressure, albeit to a lesser degree than in chamber 24. Chamber 24 within the casing houses an electrically operated alarm 31, batteries 32 to power the alarm and an electric switch 33 actuable by movement of the diaphragm 25. Alarm 31 may be a sonic alarm or a radio transmitter which may, for example, emit an FM alarm signal. Tubular element 13 may be provided with a number of open ended tubular spigots or extensions 41, 42. As indicated in Figure 2, when the painting is hung against a wall 43 the open ends of the spigot extensions 41, 42 may be adhered and sealed against the wall. When the painting is hung against the wall and the tubular extensions adhered to the wall and thus closed, suction is applied via connection 27 to create a partial vacuum with chamber 24. The fixed volume of air within chamber 1 23 and the interior of tubular element 13 then expands, moving the diaphragm 25 to a condition in which it holds switch 33 in an active or "on" condition. Thus there is created two chambers at differing sub-atmospheric pressures separated by the diaphragm 25. Any attempt to cut the art work from the frame will disrupt the seal of the tubular element 13 to the back of the painting, so causing the interior of tubular element 13 and chamber 23 to be exposed to atmospheric pressure. The resultant increase in pressure in chamber 23 will cause movement of diaphragm 25 to actuate switch 33 and so activate the alarm 31. Similarly any attempt to break through the casing to deactivate the alarm will cause an increase in pressure in chamber 24 which will also cause movement of the diaphragm and activation of the alarm. If the complete framed painting is lifted away from the wall, the sealing of the spigot extensions 41, 42 is broken which also causes activation of the alarm. Figure 6 illustrates a modified control unit 21A which is generally similar to control unit 21 of Figure 5 and in which like components have been identified by like reference numerals but with the addition of the suffix "A". In this case, however, the diaphragm chamber 23A is provided by a totally sealed casing 40 disposed within chamber 24A and chamber 24A communicates directly with the interior of the tubular element 13 Via the connector nibs 26A. The suction applied to chamber 24A via the suction fitting 27A is also applied direction to the interior of tubular element 13. This allows a significant sub-atmospheric pressure to be produced in a relatively large volume and the modified control unit is particularly suited to apparatus for protection of large-scale paintings where an extended tubular element is required. Evacuation of chamber 24A will cause diaphragm 25A to move and allow the fixed volume of air within chamber 23A to expand. This sets the switch 33A in an active or "on" condition and the alarm 31 will be activated by movement of diaphragm 25A consequent on a loss of vacuum due to interference with tubular element 13 or the casing of the control unit. The illustrated apparatus has been advanced by way of example only and it could be modified considerably. For example the alarm could be activated by a pressure responsive transducer exposed to the pressure within the tubular element 13 in place of the diaphragm chamber and diaphragm activated switch. The specific form of the tubular element may be varied and various forms of alarm could also be used. INDUSTRIAL APPLICABILITY The invention enables provision of a simple and unobtrusive means whereby framed works of art on display can be individually secured against theft.

Claims: THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. Security apparatus for the protection of a framed art work, comprising a tubular element to extend, in use of the apparatus, around the frame behind the art work; means enabling the interior of the tubular element to be held at non-atmospheric pressure; and alarm means responsive to a change in pressure in the tubular element to cause an alarm signal. 2. Security apparatus as claimed in Claim 1, wherein the means enabling the interior of the tubular element to be held at non-atmospheric pressure is such as to enable evacuation of that element to sub-atmospheric pressure. 3. Security apparatus as claimed in Claim 2, wherein the tubular element is formed with internal ribs to prevent it from collapsing. 4. Security apparatus as claimed in any one of the preceding claims, wherein the tubular element has a perforated surface which in use of the apparatus is adhered to and sealed against the back of the art work to be protected. 5. Security apparatus as claimed in Claim 4, wherein the perforated surface of the tubular element is flat to be flat against the back of the art work. 6. Security apparatus as claimed in any one of the preceding claims, wherein the tubular element comprises a length of tubing having at least one extension for attachment to a wall when the framed art work to be protected is hung from that wall such that removal of the framed art work from the wall will cause loss of vacuum pressure in the tubing. 7. -Security apparatus as claimed in Claim 6, wherein said extension has an open end and in use of the apparatus the open end is adhered to and sealed against the wall. 8. Security apparatus as claimed in any one of the preceding claims, wherein the means to enable the interior of the tubular element to be held at non-atmospheric pressure comprises a chamber for connection to with the interior of the tubular element and closed by a flexible diaphragm movable on change of pressure within the chamber and the alarm means is responsive to such movement of the diaphragm. 9. Security -apparatus as claimed in Claim 8, wherein the means to enable the interior of the tubular element 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 evacuate the ' second chamber to sub-atmospheric pressure so as to cause expansions of the first said chamber by movement of the d aphragm. 10. Security apparatus as claimed in Claim 8, wherein the means to enable the interior of the tubular element to be held at--non-atmospheric pressure comprises a vacuum connection to the chamber through which to evacuate the chamber and the interior of the tubular element to sub-atmospheric pressure.

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