GB2435994A

GB2435994A - A sight for a security door

Info

Publication number: GB2435994A
Application number: GB0604729A
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: GB0604729D0

Abstract

A sight arrangement for a door comprises an annular body 2 with a screw thread engaged by a locking ring 3 to secure a sight transparency 6 such that when assembled there is substantially no gap between the sight transparency and the annular body and/or the ring. The ring may include opposed key indents (17, Figure 2) to tighten it into the body. Substantially incompressible, 1 mm thick rubber gaskets 11, 12 may be provided between the transparency and the body and/or ring. The body or the ring may have a flange 14 for engaging about an aperture in the door. The body and ring are preferably aluminium. The ring may be locked against rotation by a screw, peg or a spot weld. The sight transparency may be made of glass and may have a chamfer or shoulder 21 on each end for engagement by the body and the ring to locate the transparency.

Description

* 2435994 A Sight Arrangement The present invention relates to sight

arrangements and more particularly to sight arrangements utilised with regard to security doors such as those used in prisons, police cells and secure hospitals.

In such institutions as prisons, police stations and secure hospitals it is important to provide appropriate secure accommodation for prisoners and restrained individuals. Clearly, such security doors must be robust and able to withstand potential percussive attack and hard usage. Nevertheless, it will also be understood that it is important to monitor individuals in the secure accommodation in order to ensure their own safety as well as prevent self harm. It is known to provide sight arrangements which comprise a port-hole type assembly incorporating a transparency typically formed from thick toughened glass. This assembly is typically permanently mounted in the door through an aperture with rubber gaskets. Generally, upon initial installation the transparency is a snug fit but nevertheless in order to accommodation variations in the door as well as the mounting assembly, the gaskets provide a degree of flexibility. Unfortunately, such flexibility and perishing of the gasket leads to a gap between the transparency and the sight arrangement mountings. This gap will enable a ligature to be secured upon which a restrained individual may do themselves damage.

In accordance with aspects of the present invention, there is provided a sight arrangement for a security door, the arrangement comprising an annular body and a lock ring to secure a sight transparency between them, the annular body having a screw thread engaged by the locking ring and the locking ring tightenable to substantially eliminate any gap between the sight transparency and the annular body and/or the locking ring.

Generally, the sight transparency is formed from a glass material.

Normally, the locking ring has key indents to facilitate tightening by rotation upon the screw thread of the annular body. Typically, the key indents are opposed.

Possibly, gaskets are provided between the transparency and the circular body and/or locking ring. Normally, the gaskets are formed from a hard non-compressive rubber material. Advantageously, the gaskets are less than 1 mm in thickness.

Typically, the annular body has mountings to enable the arrangement to be secured to a door.

Potentially, the locking ring and/or annular body have laterally extending flange members. Typically, the laterally extending flange members are arranged to capture a door through the flange members engaging about an aperture in the door.

Typically, the annular body and locking ring are formed from a metal.

Generally, the metal is aluminium.

Potentially, a rotation lock is provided. Possibly, the rotation lock comprises a screw extending through the lock ring into the annular body.

An embodiment of the present invention will now be described by way of example only with reference to the accompany drawings in which: Fig. 1 is a cross-section of a sight arrangement in accordance with aspects of the present invention; Fig. 2 is a front view of the arrangement depicted in Fig. 1; Fig. 3 is a front view of a locking ring in accordance with aspects of the present invention; and Fig. 4 is a cross-section of the locking ring depicted in Fig. 3.

As indicated above, provision of sight arrangements in security doors used in prisons and other secure accommodation is important for monitoring individuals restrained within that accommodation. Unfortunately, any gap can be utilised in order to provide an anchor for a ligature upon which the individual may attempt to commit suicide or harm themselves. Nevertheless, such security door installations have a long installation life and generally such elements as gaskets utilised for originally locating a transparency such as a thickness of toughened glass will tend to perish over the years and gaps develop. Furthermore, as the installations are robust, it is typical for the installations not to be particularly suitable for maintenance, again leading to difficulties with respect to accommodating gap development between the transparency and the sight arrangement mountings.

In accordance with aspects of the present invention, an annular body or housing is utilised with a locking ring secured upon a screw thread to allow adjustment for variations both at installation and during the lifespan of the sight arrangement. It will be understood that the locking ring can move along the screw thread of the annular housing to an extent necessary to ensure that there is substantial elimination of any gap with a retained transparency such as a toughened glass insert. Thus, gaps will not be provided for anchoring ligatures.

Figs. 1 and 2 respectively illustrate in Fig. 1 a cross-section, along the line A-A depicted in Fig. 2 and a front view depicted in Fig. 2 of a sight arrangement 1 in accordance with aspects of the present invention. Thus, the arrangement comprises an annular housing or body 2 and a locking ring 3 with a transparency 6 secured between the housing 2 and the ring 3. It will be appreciated that the body 2 will have a circular section 4 to accept the locking ring 3 but other parts 5 as well as the transparency 6 may be differently shaped such as square provided the transparency 6 can enter through an aperture provided by the sections 4 to engage flange parts 7 of the housing 2.

A screw thread relationship between the housing 2 and the locking ring 3 is provided to allow displacement in the direction of arrowheads 8. In such circumstances, any gaps 9, 10 between the ring 3 and the flanges 7 can be substantially eliminated. However, to avoid surface grinding of the transparency 6, particularly when formed from a glass material, thin gaskets 11, 12 can be provided. These gaskets 11, 12 will be of a skim form and will typically be less than 1 mm in thickness. The gaskets 11, 12 will also be made from solid rubber to eliminate any further possibility of gaps being created between the transparency 6 and other parts of the arrangement 1 within which a ligature can be secured.

It will also be understood that as the locking ring 3 is displaced upon the screw thread the transparency can be removed and periodically new gaskets 11, 12 located in place. Thus, in life perishing of these gaskets will not be sufficient to cause creation of gaps.

As can be seen from a front view as depicted in Fig. 2, the transparency 6 is essentially surrounded by a relatively smooth surface 13. A laterally extending flange 14 in use will engage peripheral parts of an aperture in a security door in order to retain the arrangement 1 in place. In such circumstances, typically a mounting plate (not shown) may be provided on the other side of the door such that through mountings 16 the housing secures location of the arrangement in the door. Alternatively, a locking ring may be arranged to extend itself with laterally extending flanges to engage peripheral edges of the door aperture on the other side of the door to those engaged by the flanges 14 in order to capture the door between those flanges 14 and those of the locking ring.

In the above circumstances, it will be understood that a transparency is secured by rotation of the locking ring. Such rotation is facilitated by providing key indents 17 which will be generally engaged by a tool to allow rotation of the ring until a particular torque value is achieved to ensure that there is limited if any gap 11, 12 between the transparency 6 and the ring and flange 7. Normally, the indents 17 will be opposed and arranged to receive an assembly tool to allow rotation for entry of the locking ring into the body 2.

Figs. 3 and 4 illustrate the locking ring 3 in accordance with aspects of the present invention. Fig. 3 is a front view of the locking ring 3 whilst Fig. 4 is a cross-section in the plane B-B of the ring depicted in Fig. 3. Thus, as can be seen, the ring incorporates key indents 17 with screw threads 18 about the edge of the ring 3. The screw threads 18 allow assembly by entry of the ring upon a screw thread 18 in the body 2 (Fig. 1).

The ring 3 has an aperture 19 to allow sight through the transparency 6. It will be understood that an abutment part 20 of the ring 3 will engage the transparency 6 in order to secure it. Thus, this abutment part 20 should be sufficiently broad to engage an appropriate proportion of the transparency 6 to secure it in association with other parts of the arrangement. Furthermore, parts of the transparency 6 may be chamfered or have a shoulder rebate illustrated by broken line 21 in Fig. 1 into which the locking ring 3 enters to further ensure appropriate location of the transparency in the arrangement.

Similar shouldered or chamfered rebates to the transparency may also be provided with regard to the front side of the transparency where engaged by the housing.

As indicated, rotation of the locking member allows accurate assembly of the arrangement to avoid gaps. However, by reverse rotation it will be understood that the transparency can be removed to allow replacement of that transparency or gasket or any other part of the arrangement. In such circumstances, in order to maintain security typically an anti-rotation locking mechanism may be provided either in the form of a screw which passes through the locking ring into a part of the body 2 or through a spot weld or locking peg.

As indicated above, positional and structural integrity is important with regard to arrangements 1 in accordance with aspects of the present invention.

Thus, materials which will not readily deform under percussive loads or during installation life will be used. Thus, typically metals will be used to form the housing 2 and the locking ring 3. Typically this metal will be aluminium.

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 sight arrangement for a security door, the arrangement comprising an annular body and a lock ring to secure a sight transparency between them, the annular body having a screw thread engaged by the locking ring and the locking ring tightenable to substantially eliminate any gap between the sight transparency and the annular body and/or the locking ring 2 An arrangement as claimed in claim 1 wherein the sight transparency 1 0 is formed from a glass material.

3 An arrangement as claimed in claim I or claim 2 wherein the locking ring has key indents to facilitate tightening by rotation upon the screw thread of the annular body * I I.e.

4 An arrangement as claimed in claim 3 wherein the key indents are :.:. opposed I....

S

An arrangement as claimed in any preceding claim wherein gaskets n... 20 are provided between the transparency and the circular body and/or locking I... * . I...

6 An arrangement as claimed in claim 5 wherein the gaskets are formed from a hard non-compressive rubber material.

7 An arrangement as claimed in claim 5 or claim 6 wherein the gaskets are less than 1mm in thickness.

8 An arrangement as claimed in any preceding claim wherein the annular body has mountings to enable the arrangement to be secured to the door.

9 An arrangement as claimed in any preceding claim wherein the locking ring and/or annular body have laterally extending flange members.

An arrangement as claimed in claim 9 wherein the laterally extending flange members are arranged to capture a door through the flange members engaging about an aperture in the door.

11 An arrangement as claimed in any preceding claim wherein the annular body and the locking ring are formed from a metal 12 An arrangement as claimed in claim 11 wherein the metal is aluminium.

13 An arrangement as claimed in any preceding clairi wherein the rotation lock comprises a screw extending through the lock ring into the annular body * S S...

14 An arrangement as claimed in claim 13 wherein the rotation lock comprises a screw extending through the lock ring into the annular body. * S....

15. A sight arrangement for a security door substantially as hereinbefore ... 20 described with reference to the accompanying drawings. S... * S *..S

16 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.