GB2119144A - Security alarms in association with concrete structures - Google Patents

Abstract

A concrete structure, in particular a precast concrete wall (2), has a security alarm assembly (1,7) associated therewith for providing an alarm condition if an access aperture is formed through the structure or wall. The alarm assembly includes tangible conductors (1) on the structure or wall such that a conductor will be broken when an access aperture is formed. Various forms of attaching the conductors to the concrete structure and wall are envisaged, such as by adhesively securing them (at 3) to the outer concrete surface; embedding them during casting of the concrete; and thereby then through tubes cast into the concrete. <IMAGE>

Description

SPECIFICATION The provision of security alarms in association with concrete structures This invention relates to the provision of security alarms in association with concrete structures of a type which are capable of being broken by unauthorised persons wishing to gain access through a concrete structure such as a wall. Of particular interest are concrete walls composed of prefabricated panels located in vertically stacked relationship relative to each other and located at their ends by means of posts fixed relative to the ground.

From both a protection and a lack of visibility point of view, a concrete wall or the like is most attractive in security applications. However, from a security point of view it has, as far as applicants are aware, not been possible to provide such a concrete wall with an effective security alarm and such a security alarm is a prerequisite in many cases.

In many instances, where walls would otherwise have been employed, as a result of the deficiency of security alarms as applied to concrete walls, security alarm fences have been employed.

It is the object of this invention to provide a method and means of alarming concrete walls and, in particular, but not exclusively, concrete walls of the prefabricated type and composed of vertically stacked panels located by means of posts.

In accordance with one aspect of this invention there is provided, in combination, a concrete wall and a security alarm assembly in association therewith, the concrete wall having electrical conductors extending between predetermined positions thereon at which positions the conductors are permanently secured to the wall such that forces tending to stretch the conductor above a predetermined minimum cause breakage of the conductor and means for sensing breakage and/or tampering with said conductors.

Further features of the invention provide for the conductors to be located in their own electrically insulating sheaths; for the conductors to be adhesively secured to the outer surface of a concrete wall at spaced positions as may be required and, in particular, over regions susceptible to breakage; for the conductors alternatively to extend through the concrete itself and either in tubular formations provided within the concrete or alternatively for the insulated conductors to be directly embedded in the concrete; and for the concrete structure to be a prefabricated concrete wall composed of a series of vertically stacked prefabricated concrete panels located by means of posts at the ends of the panels.

The invention also provides precast concrete panel adapted for forming walls by vertical location thereof relative to other panels said panel including one or more conductors embodied therein or alternatively one or more tubular formations adapted to receive one or more conductors passing therethrough.

Futherfeatures of this aspect of the invention provide for the conductors or tubes to extend longitudinally throught the panel along the length thereof; for the conductors to extend, in the case of a panel having no apertures therethrough, substantially straight along the length thereof, and in the case of a panel having a grille or other aperture formation for the conductor to follow the concrete portions defining the apertures; and for the conductors or tubes for receiving conductors to communicate with the surface of the panels short of the ends thereof which are adapted to be received in locating grooves in co-operating posts in use.

It is preferred that the conductors be in the form of a plurality of individually insulated stranded wires twisted together and whereof selected wires are employed as "live" alarm wires. This adds to the security of the system.

It will be understood that the invention can be applied to many different forms of concrete structures which are susceptibie to breakage by unauthorised persons wishing to gain entry through such structures but, in general, byfarthe largest application will be to prefabricated concrete walls of the type comprising a plurality of elongate vertically stacked panels located between posts at the ends of such panels. Accordingly, the embodiments of the invention described below will be directed towards prefabricated concrete walls of the aforementioned type but this fact is not to be interpreted as being limitative to the scope of the invention.

In the following description reference will be made to the accompanying drawings in which: Figure 1 is an isometric view of a section of prefabricated concrete walling having alarm conductors attached thereto as provided by the invention; Figure 2 is a similar view of a single panel illustrating a form of the ivention in which conductors are embodied within the panel; Figure 3 is a similar view illustrating a panel embodying tubular formations for receiving conductors therein subsequent to moulding of the panel; and Figure 4 illustrates in elevation the path which conductor wires may follow in the case of apertured or grille type of concrete panel.

it will be understood that the structural details of the panel are irrelevant to the present invention and, accordingly, in each of the following embodiments of the invention, the panels could be simple, unreinforced concrete panels: reinforced concrete panels: or post-stressed or prestressed concrete panels, in each case of any suitable or required thickness.

In any event, referring to Figure 1, one embodiment of the invention envisages the application of a security alarm assembly to a wall of conventional panels. Thus, as illustrated, fairly lightweight insulated conductor wires 1 are adhesively secured to a prefabricated concrete wall 2 by means of small zones of adhesive 3 located at spaced positions on both the individual panels 4 and the vertical posts 5 constituting the wall. The locations of the adhesive securing of the conductor to the wall are chosen such that, in the event that a panel is broken out from between two posts, the braking action itself may cause the conductor to fracture but, in any event, in order to remove the panel so as to provide an opening, the conductor would fracture at some position along its length and between two adjacent posts.

Clearly the conductor wire is connected to suitable alarm circuitry simply indicated diagrammatically by numeral 7 such that, when the conductor is fractured, an alarm condition is given.

It will be understood that the pattern of the conductors on the concrete wall could be any required pattern and is chosen such that fracturing of the conductor wire will, without doubt, occur when an access aperture is formed through the concrete wall. However, in general, it is envisaged that the conductors will extend longitudinally along the length of the individual panels as illustrated in Figure 1.

Turning now to Figure 2, there is illustrated a panel in which one or more insulated conductors 8 have been embedded during the manufacture thereof.

The conductors are arranged to emerge from the surface 9 of the panels at distances somewhat inwardly of the free ends 10 thereof such that the end regions can be located in the conventional grooves 11 (see Figure 1) in the locating posts therefore.

Again, the conductors are adhesively secured to the posts to ensure that an alarm condition is given even in the event that the conductor fails to fracture when the panel is broken along its length but is then broken when an attempt is made to remove the panel from the parts. The adhesive securing of the conductors is indicated by numeral 12 in Figure 2.

As an alternative to the embedding of the conductors in the precast concrete panels a tubular member 13 may be cast therein to extend along the lengths of the panels in substantially the same arrangement as in the case of the conductors described with reference to Figure 2. In such a case the conductors themselves can be threaded into the tubes at a time convenient to the manufacturer and the conductors can be adhesively secured to locating posts as above described. This arrangement is illustrated in Figure 3 of the drawings.

Referring now to Figure 4, it will be clearthat the conductors 14 can be embedded in panels having a grille or apertured configuration and the conductors can, in such a case, simply follow the concrete about a tortuous path as it defines the apertures through the panel. Such an arrangement is necessary where drainage apertures are required through panels, for example at the base of a concrete wall.

It will be understood that the conductors may be rendered extremely easily fractured in which case the adhesive securing, in the instance where the conductors are cast into the panels, may be rendered unnecessary. Also, where the conductors are threaded through a tube in the panel and the conductor is adhesively secured to the tube at the ends thereof, the adhesive securing to the posts may again be rendered unnecessary.

In each case the conductors can assume the form of a plurality of individually insulated stranded wires twisted together and whereof only one or more of the wires are used as "live" security alarm wires. In such a case the security alarm circuitry is such that any wire incorrectly bridged or connected to another would trigger the alarm.

It will be understood that the invention provides an extremely simple yet effective method and means for providing a security alarm arrangement in combination with a concrete structure and, in particular, a precast concrete wall.

Claims (9)

1. In combination, a concrete wall and a security alarm assembly in association therewith, the concrete wall having electrical conductors extending between predetermined positions thereon at which positions the conductors are permanently secured to the wall such that forces tending to stretch the conductor above a predetermined minimum cause breakage of the conductor and mans for sensing breakage and/ortampering with said conductors.

2. A combination as claimed in claim 1 in which the conductors are located in their own electrically insulating sheaths.

3. A combination as claimed in either of claims 1 or 2 in which the conductors are adhesively secured to the outer surface of the concrete wall at required spaced positions.

4. A combination as claimed in either of claims li or 2 in which the conductors are embedded in the concrete during casting thereof.

5. A combination as claimed in either of claims 1 or 2 in which the conductors extend through tubular formations which are embedded in the concrete during casting thereof.

6. A combination as claimed in claim 5 in which the conductors are adhesively secured to the concrete or tubular formations at said predetermined positions.

7. A combination as claimed in any one of the preceeding claims in which the conductors are in the form of twisted insulated conductors of which selected conductors are employed as "live" conductors.

8. A combination as claimed in any one of the preceeding claims in which the concrete structure is a prefabricated concrete wall composed of a vertically stacked series of prefabricated concrete panels located by means of posts engaging the ends of the panels.

9. A precast concrete panel as claimed in Claim 5 and substantially as herein described with reference to any of the accompanying drawings.

9. A combination as claimed in claim 8 in which the conductors extend in the general longitudinal direction of the panels.

10. A precast concrete panel adapted for forming walls by vertical location thereof relative to other panels said panel including one or more conductors embedded therein or alternatively one or more tubular formations adapted to receive one or more conductors passing therethrough.

11. A precast concrete panel as claimed in claim 10 in which the conductors extend substantially straight along the length thereof.

12. A precast concrete panel as claimed in claim 10 in which the panel has one or more apertures therethrough and the conductors pass through concrete zones adjacent such apertures.

13. A combination as claimed in claim 1 and substantially as herein described with reference to any of the accompanying drawings.

14. A precast concrete panel as claimed in claim 10 and substantially as herein described with reference to any of the accompanying drawings.

New claims or amendments to claims filed on 17.3.83.

Superseded claims 1-14 New or amended claims:

1. In combination, a concrete wall and a security alarm assembly in association therewith, the concrete wall having electrical conductors extending between predetermined positions thereon at which positions the conductors are permanently secured to the wall such that forces tending to stretch the conductor above a predetermined minimum cause breakage of the conductor and means for sensing breakage and/or tampering with said conductors, the conductors being arranged in one of the following ways: (i) adhesively secured to the outer surface of the concrete wall at required spaced positions, or, (ii) being sheathed in their own electrically insulating sheaths and embedded directly in the concrete during casting thereof.

2. A combination as claimed in Claim 1 in which the conductors are in the form of twisted individually insulated conductors of which selected conductors are employed as "live" conductors.

3. A combination as claimed in either of the preceding claim in which the concrete structure is prefabricated concrete wall composed of a vertically stacked series of prefabricated concrete panels located by means of posts engaging the ends of the panels.

4. A combination as claimed in Claim 3 in which the conductors extend in the general longitudinal direction of the panels.

5. Aprecastconcrete panel adaptedforforming walls by vertical location thereof relative to other panels said panel including one or more conductors having its own electrically insulating sheath embedded therein.

6. A precast concrete panel as claimed in Claim 5 in which the conductors extend substantially straight along the length of the panel.

7. A precast concrete panel as claimed in Claim 5 in which the panel has one or more apertures therethrough and the conductors pass through concrete zones adjacent such apertures.

8. A combination as claimed in Claim 1 and substantially as herein described with reference to any of the accompanying drawings.