GB2128655A

GB2128655A - Improvements in and relating to security bars

Info

Publication number: GB2128655A
Application number: GB08327318A
Authority: GB
Inventors: John Bootland
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-10-15
Filing date: 1983-10-12
Publication date: 1984-05-02
Also published as: GB8327318D0; GB2128655B

Abstract

A Security Bar comprises an outer tubular casing 1 and a wear-resistant sleeve 3 mounted for free rotation within the other casing and about the circumference of an inner rod 2. An indicator medium 5 is present within the annulus between the casing and the sleeve. <IMAGE>

Description

SPECIFICATION Improvements in and relating to security bars This invention relates to security bars.

Hitherto, security bars to windows, doors etc have been manufactured from a metal such as steel. New developments in tooling, eg tunsten carbide tipped saws, have significantly reduced the time taken to cut through such bars thereby minimising their effect. Additionally, with conventional bars, partial cuts can readily be disguised by the insertion of a suitably colored material eg. dirt, soap etc.

Security bars have been proposed previously which include a freely rotatable metal rod housed within a tubular outer casing. Whereas the presence of an internal rotatable rod hinders attempts to saw through the bar, breaching of the bar can be achieved in time either by restricting the free movement of the rod or by using a cutting tool, eg a thermic lance, which does not require the object to be cut to be restrained against movement.

Security bars have also been proposed which embody electrical wiring connected into external alarm security, an alarm being sounded upon the wiring being cut. In practice, electrical systems have been found to be unreliable and can be circumvented reasonably simply. In addition, because they form part of a larger system, such security bars are relatively expensive to instal and to maintain.

The present invention sets out to provide an integral security bar which is not reliant upon external alarm systems and which meets the dual requirements of inhibiting breach by conventional cutting means and alerting an observer upon casual inspection to an attempted breach so enabling remedial action to be taken.

According to the present invention in one aspect, there is provided a security bar comprising an outer tubular casing, a wear resistant sleeve mounted for free rotation within the outer casing and about the circumference of an inner rod, and an indicator medium present in the annulus between the casing and the sleeve.

A second freely rotatable sleeve may be positioned about the circumference of the first sleeve or the inner rod.

An indicator meduim may also be present in the annulus between the sleeve(s) and the rod and may comprise a dye or other visible indicator, or odiferous fluid or a radioactive tracer.

The or each sleeve may be formed in several tubular sections, each sleeve section end being so shaped that no joint between two assembled sleeve sections lies in a single plane.

The casing and the rod may both be manufactured from a toughened steel or a similar alloy eg. a chrome molybdenum alloy steel. One or each end of the casing or the rod may be ribbed or provided with a screw threadfor anchoring purposes.

The sleeve may be manufactured from a hard wearing abrasion resistant material such as a carbide, manganese steel, ceramic or glass material. The rod may also be manufactured from such an abrasion resistant material.

The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings, in which:~ Figure 1 is a longitudinal section taken through a security bar in accordance with the invention; Figure 2 is a cross section taken along line 11- II of Figure 1; Figure 3 is a longitudinal section taken through an alternative security bar in accordance with the invention; and Figure 4 is a longitudinal section taken through a sleeve member of a security bar in accordance with the invention.

The security bar illustrated in Figures 1 and 2 of the drawings comprises an outer toughened steel casing 1 containing a toughened steel rod 2 mounted for free rotation within a wear resistant sleeve 3. The casing has toughened steel caps welded to its upper and lower end through which the rod 2 protrudes. In one construction, the casing 1 is manufactured from steel of specification BS 3059-622 heat treated to approximately 350 Brinell, the central rod 2 from steel to specification ASTM 87 or Durehete 900 and the sleeve 3 from isostatically pressed powdered tungsten carbide.

The annuli between the sleeve 3 and the casing 1 and the sleeve 3 and the rod 2 is filled with a liquid indicator, suitably a brilliant coloured permanent staining liquid to dye 5 which an oderferous compound has been added.

The ends of the rod 2 protruding from the casing are ribbed or screw threaded to provide additional grip in grouting or other material employed to anchor the bars in place.

To manufacture the security bar, the lower cap 4 is welded to the lower open end of the casing 1 and the rod 2 inserted through the cap aperture and the corresponding aperture formed in the base of the casing. The sleeve 3 is then inserted about the rod and the annuli between the sleeve and the casing, and the sleeve and rod are then filled with the indicator liquid 5. Finally, the upper cap is welded to the upper open end of the casing to provide a sealed unit.

Turning now to Figure 3, the security bar illustrated again comprises an outer tubular toughened and/or hardened steel casing 1, an inner rod 2 of toughened steel and a freely rotatable wear resistant sleeve 3 of a relatively hard material e.g. carbide. In this embodiment however, a second freely rotatable sleeve 6 is positioned within the casing 1 and about the circumference of the wear resistant sleeve 3. The sleeve 6 may be manufactured from a carbide material or from a material not having the relative hardness of a carbide. Indicator fluid is present in the annulus between the casing and the sleeve 6 in addition to the annuli between the two sleeves 3.6 the casing 1 and the rod 2.

The or each sleeve 3, 6, may comprise an assembly of abutting sleeve sections. Such a sleeve section is illustrated in Figure 4 and is formed at one end with a recess 7 dimensioned to receive a complementary abutment 8 forced on the adjoining end of the adjacent sleeve section.

The presence of the recess and abutment ensures that the joins between adjacent sleeve sections do not lie in a single plane.

Security bars as described enjoy several advantages; thus, any break in the integrity of the casing 1 will result in an immediate release of indicator fluid 4 which will be detectable from several feet distance on simple inspection; the outer casing 1 is of a material which is sufficiently hard to deter a casual theft; the wear resistant material of the or each sleeve 3 will resist conventional tooling due to its hardness; the fact that the sleeve(s) can revolve makes it extremely difficult to obtain sufficient purchase for cutting; and the central toughened steel rod 2 is resistant to the bar being broken by bending or pulling rather than cutting.

It is to be understood that other materials and alternative indicators such as a radioactive tracer may be employed.

Claims

1. A security bar comprising an outer tubular casing, a wear resistant sleeve mounted for free rotation within the outer casing and about the circumference of an inner rod, and an indicator medium present in the annulus between the casing and the sleeve.

2. A security bar as claimed in Claim 1 including a second freely rotatable sleeve positioned about the circumference of the first sleeve or the inner rod.

3. A security bar as claimed in Claim 1 or Claim 2 wherein an indicator medium is present in the annulus between the sleeve(s) and the rod.

4. A security bar as claimed in any one of the preceeding claims wherein the indicator medium comprises a dye or other visible indicator, an odiferous fluid or a radioactive tracer.

5. A security bar as claimed in any one of the preceeding claims wherein the or each sleeve is formed in several tubular sections, each sleeve section end being so shaped that no joint between two assembled sleeve sections lies in a single plane.

6. A security bar as claimed in any one of the preceeding claims wherein the casing and the rod are manufactured from a toughened steel.

7. A security bar as claimed in Claim 6 wherein the steel is a chrome molybdenum alloy.

8. A security bar as claimed in any one of the preceding claims wherein one or each end of the casing or the rod is ribbed or provided with a screw thread for anchoring purposes.

9. A security bar as claimed in any one of the preceeding claims wherein the or each sleeve is manufactured from a hard wearing abrasion resistant material such as a carbide, manganese steel, ceramic or glass material.

10. A security bar substantially as herein described with reference to Figures 1 and 2, or Figures 3, or Figure 4 of the accompanying drawings.