GB2435992A

GB2435992A - Security door with reinforced optically switchable panel

Info

Publication number: GB2435992A
Application number: GB0604726A
Authority: GB
Inventors: Andrew Peter Morris
Original assignee: CELL SECURITY Ltd
Current assignee: CELL SECURITY Ltd
Priority date: 2006-03-08
Filing date: 2006-03-08
Publication date: 2007-09-12
Also published as: GB0604726D0

Abstract

A security door comprises a panel formed as a ply of an optically switchable sheet 6, 7 and a reinforcing transparency. The sheet is switchable from substantially opaque to being, at least one way, substantially transparent. Preferably the switchable sheet is sandwiched between two layers of reinforcing transparency by lamination or by adhesive. The reinforcing transparency may be polycarbonate or toughened glass and the switchable sheet or the transparency may include a mesh comprising metal, fibre or plastics strands. A lock 3 may be provided in an intermediate section of the door between two panels 6, 7 and the panels may be secured to the door by frames 16, 17 bolted or riveted to the door. The portion of the panel which is switched between opaque and transparent may be controlled as may the extent of transparency. This may allow a camera to be concealed by the panel while part of the panel is transparent. The panel may be such that when transparent it allows viewing in both directions. The panel may be rendered a particular colour when opaque.

Description

Security Doors The present invention relates to security doors and more

particularly to security doors used in prisons, police stations and secure accommodation.

It will be understood that security doors in prisons, police stations and secure hospitals must be robust and able to withstand harsh treatment.

Nevertheless, the capability of viewing a restrained individual at least periodically to ensure their own safety as well as continued presence in the secured accommodation is generally a necessity. Systems are known which include use of sight viewers and similar arrangements but generally only provide limited viewing area and may be unacceptable in certain environments.

In accordance with aspects of the present invention there is provided a security door comprising a panel formed as a ply combination of an optically switchable sheet and a reinforcing transparency, the optically switchable sheet being switchable from a substantially opaque mode to a substantially, at least one way, transparent mode to enable viewing through the panel.

Generally, the optically switchable sheet is sandwiched between sheets of reinforcing transparency.

Possibly, the optically switchable sheet is secured to the reinforcing transparency by lamination. Alternatively, the optically switchable sheet is secured to the reinforcing transparency by an adhesive.

Generally, the optically switchable sheet when in the transparent mode allows viewing through the panel in both directions.

Typically, the reinforcing transparency is toughened glass.

Alternatively, the reinforcing transparency is a plastics material such as polycarbonate. Possibly, the optically switchable sheet and/or the reinforcing transparency incorporate a mesh. Possibly, the mesh is formed from a metal wire or fibre or plastic strands.

Possibly, the door has a frame bolted about an aperture in the door to retain the ply combination.

Advantageously, the door has two panels divided by an intermediate door section. Typically, the intermediate door section incorporates a locking mechanism.

Advantageously, the door is associated with a control to enable selective operation of the optically switchable sheet between the opaque mode and the transparent mode. Possibly, the control can selectively operate parts of the optically switchable sheet to vary the size of the optically switchable sheet rendered transparent in the transparent mode. Potentially, the control may be able to provide an intermediate state with regard to the level of transparency in the optically switchable sheet.

An embodiment of the present invention will now be described by way of example and with reference to the accompanying drawing in which:-Fig, 1 is a front view of a security door in accordance with aspects of the present invention; Fig. 2 is a side view of a security door as depicted in Fig. 1 located within a wall aperture; and, Fig. 3 is a plan view of the door and wall cross sections depicted in Fig. 2.

As indicated above, provision of security doors is important in secured accommodation as provided in prisons, police stations and secure hospitals.

These doors by their nature are typically made from metal or stout wooden frames. In situations where it is desirable to provide close and regular monitoring of a restrained individual it is important that individual can be seen, but the potential disturbance of opening the door for such viewing should be avoided. By aspects of the present invention an optically reactive or switchable panel is provided in a door.

Fig. 1 illustrates a security door 1 in accordance with aspects of the present invention. Thus, the door generally comprises a frame with a central section 2 to accommodate a lock 3. The door itself is located within a door frame 4 which will generally be reinforced about a latch recess 5.

In the embodiment of the present invention as depicted in Fig. 1 has two panels 6, 7. These panels are formed from a ply comprising an optically switchable sheet of material between at least an opaque and a transparent mode of operation reinforced with a transparency in order to render the door 1 and in particular the panel 6, 7 resistant to percussive attack. It will be understood that reinforcement is required to render the optically switchable sheet suitable for high security usage.

The panels 6, 7 will typically be reinforced with two layers of transparency sandwiching the optically switchable sheet between them. The thickness of the transparencies which will tend to be a toughened glass or plastic material will be determined by the door once sufficiently robust for operational use.

It will be understood by switching the optically switchable sheet material from a substantially opaque mode when it is not possible to look through the door 1 and in particular the panels 6, 7 to a state where there is substantial transparency will enable viewing of an individual as required. In such circumstances, monitoring of that individual or the cell can be achieved.

Typically, the frame 4 will be mounted against a wall with bolts 8 to ensure that the door 1 with frame 4 are robustly secured. Figs. 2 and 3 illustrate the door when located in a wall 9 with the door appropriately secured through a hinge 10 within the frame 4. As can be seen, the door 1 with its frame 4 is generally presented to an aperture 11 in the wall 9 from an external frame away from the cell 12. Thus, the door with the frame can be presented and the bolts 8 located as appropriate to secure the external frame in the form of a flange extending around the aperture 11. Typically, a surface screed of plaster 13 or similar material will be provided about the wall 9 and a floor chase 14 also provided in order to ensure that the door is robustly located within the wall 9.

Generally, the panel 6 is formed from a ply combination as indicated with an optically switchable sheet associated with a reinforcing transparency.

This association is typically through lamination but may be achieved alternatively by an appropriate adhesive processes. Typically, as can be clearly seen in Fig. 3, the panel will have a relatively thin section and typically in the order of 22mm. Nevertheless, particularly where reinforced glass is used to reinforce the optically switchable sheet, the door 1 will have a substantial weight in the order of 250Kg.

The optically switchable glass is available from Sam Gobain Glass and a number of patent applications have been filed which describe the process for providing switching between a darkened (opaque) mode and clearer transparency. Essentially, the glass incorporates electrodes to allow through creation of electrical potential across the electrodes variation on the transparency of the optically switchable sheet. Normally, the optically switchable sheet will be opaque but when electrical charge is presented across electrodes the transparency of the sheet will improve, It may be possible to create situations where there is a hazy or translucent status with regard to transparency, but typically, as illustrated, full transparency, or as near to that transparency as possible, will be required in order to view the interior of the cell.

As can be seen, the panels 6, 7 are generally secured through frames 16, 17 which themselves are secured to the door 1 through rivets etc. In operation it may be possible to specifically control the respective panels 6, 7 such that one is rendered opaque whilst the other is translucent or vice versa dependent upon operational requirements. Furthermore, individual segments of the respective panels 6, 7 in terms of the optically switchable sheet may be rendered transparent such that in certain circumstances only a sight strip may be rendered transparent to allow internal viewing of the cell 12.

In order to further reinforce the panel 6, 7 a mesh will be incorporated into the reinforcing transparency or, where possible, the optically switchable sheet itself. This mesh may be formed from a wire or plastic thread or fibres as required in order to further improve the robustness and strength of the panels for security purposes at least.

In addition to simple switching between opaque and transparent it will be understood that the opaque colour of the panel 6, 7 can be adjusted or provided as required. Thus, the panel 6, 7 may be rendered a particular colour when opaque consistent with a classification of a cell or as required.

Furthermore, when transparent a tint may be provided to the panel 6, 7.

Where possible, the optically switchable sheet may be arranged within the panel 6, 7 to allow one way viewing, that is to say into the cell 12 such that the applicant may not be aware that they are being observed.

Although illustrated as rectangular panels 6, 7 it will be appreciated that these panels may be formed in different shapes including circular, triangular and slit.

The security door in accordance with aspects of the present invention may be a panel in front of a camera to protect or hide that camera, but to allow periodically the panel to be rendered transparent for viewing. Thus, selective areas may be obscured from view when required.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

CLAIMS

1 A security door comprising a panel formed as a ply combination of an optically switchable sheet and a reinforcing transparency, the optically switchabie sheet being switchable from a substantially opaque mode to a substantially, at least one way, transparent mode to enable viewing through the panel 2 A door as claimed in claim I wherein the optical switchable sheet is sandwiched between sheets of reinforcing transparency.

:. 3 A door as claimed in claim 1 or claim 2 wherein the optical switchable * sheet is secured to the reinforcing transparency by lamination. S... * S S...

4 A door as claimed in claim I wherein the optical switchable sheet is : *. secured to the reinforcing transparency by an adhesive. *..S.

:. 5 A door as claimed in any preceding claim wherein the optically :*I::: 20 switchable sheet when in the transparency mode allows viewing through the panel in both directions 6 A door as claimed in any preceding claim wherein the reinforcing transparency is toughened glass 7 A door as claimed in claims 1 to 5 wherein the reinforcing transparency is a plastics material such as polycarbonate.

8. A door as claimed in any preceding claim wherein the optically switchable sheet and/or the reinforcing transparency incorporate a mesh 9 A door as claimed in claim 8 wherein the mesh is formed from a metal wire or fibre or plastic strands A door as claimed in any preceding claim wherein the door has a frame bolted about an aperture in the door to retain the ply combination 11 A door as claimed in any preceding claim wherein the door has two panels divided by an intermediate door section.

12 A door as claimed in claim 11 wherein the intermediate door section incorporates a locking mechanism.

13 A door as claimed in any preceding claim wherein the door is associated with a control to enable selective operation of the optically 1 5 switchable sheet between the opaque mode and the transparent mode. S. *S

* .. * * . 14 A door as claimed in claim 13 wherein the control can selectively *.* operate parts of the optically switchable sheet to vary the size of the optically switchable sheet rendered transparer. in the transparent . 20 mode *.SS A door as claimed in claim 13 or in claim 14 wherein the control may be able to provide an intermediate state with regard to the level of transparency in the optically switchable sheet.

16 A security door substantially as hereinbefore described with reference to the accompanying drawing.

17 Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.