Security device and system

Abstract

A strainer for straining a length of material, the strainer including a tensioning device configured to tension a length of material between the strainer and an object, characterized in that the strainer includes a conductive component configured to contact the length of the material when held by the tensioning device, and wherein the conductive component includes an attachment portion for an external conductive link to the strainer. This invention also relates to a security system and its method of preparation using the strainer as described herein.

Claims

1. A strainer for straining a length of conductive material, the strainer including: a non-conductive housing; and a tensioning device mounted in the housing configured to be actuated to tension the length of material between the strainer and an object, the tensioning device including: an axle configured to rotate about its longitudinal axis relative to the housing, the axle including: a hollow portion extending from at least one end of the axle along at least a portion of the longitudinal axis; and an aperture in a side of the axle into which the length of material may be inserted, wherein the aperture extends across the hollow portion; an elongate insert configured to be received by the hollow portion of the axle, and move relative to the aperture along the longitudinal axis of the axle to contact and apply a force to the length of the material when inserted through the aperture, and wherein the elongate insert includes an attachment portion configured to extend through a portion of the housing and engage with a conductive link external to the housing.

2. A strainer as claimed in claim 1 wherein the elongate insert is configured to slidably fit within the hollowed portion of the axle.

3. A strainer as claimed in claim 1 wherein the elongate insert has at least one protrusion extending from a first end.

4. A strainer as claimed in claim 3 wherein the hollow portion of the axle includes a recess complementary to the protrusion of the elongate insert.

5. A strainer as claimed in claim 1 wherein the elongate insert includes a recess along a portion of its length.

6. A strainer as claimed in claim 5 wherein the hollow portion of the axle includes a protrusion complementary to the recess of the elongate insert.

7. A strainer as claimed in claim 1 wherein the attachment portion of the elongate insert has a fastener engagement portion configured to engage with a fastener.

8. A strainer as claimed in claim 7 wherein the fastener engagement portion of the attachment portion of the elongate insert has a threaded portion configured to engage with a corresponding nut.

9. A strainer as claimed in claim 1 including a locking mechanism configured to allow locking of the tensioning device in either a first or second direction.

10. A security system including at least one strainer as claimed in claim 1, wherein a length of conductive material is attached to the tensioning device of at least one strainer and in contact with the elongate insert in the strainer, wherein the strainer is also connected to an electric fence energizer via a length of material which is secured by the attachment portion of the elongate insert of the strainer.

11. A security system including: at least two strainers, each having a non-conductive housing; and a tensioning device mounted in the housing and including an axle configured to rotate about its longitudinal axis relative to the housing, the axle including an engagement portion configured to engage a length of material and a hollow portion extending from at least one end of the axle along at least a portion of the longitudinal axis, wherein the tensioning device is configured to tension the length of material between the strainer and an object an elongate insert configured to be received by the hollow portion of the axle and contact the length of material at the engagement portion, wherein the elongate insert includes an attachment portion configured to extend through a portion of the housing, wherein at least one of the strainers is also connected to at least one other strainer of the security system via attachment of an external conductive link to the respective attachment portions of the elongate inserts of the respective strainers.

12. A security system as claimed in claim 11 wherein the conductive link is configured as an elongate arm with a linking point at both ends.

13. A security system as claimed in claim 12 wherein the linking points of the conductive link are configured to fit on the attachment point of the respective elongate inserts.

14. A method of constructing a security system as claimed in claim 11, the method including the steps of: a) attaching a portion of a length of conductive material to the tensioning device of a first strainer wherein the length of material contacts a portion of the elongate insert on the first strainer; b) attaching a different portion of the length of material to the tensioning device of a second strainer wherein the length of material is positioned to be able to contact a portion of the elongate insert on the second strainer; c) attaching a conductive link from the first and/or second strainer to at least one additional strainer, wherein the conductive link is secured using the attachment portion of the elongate insert of the respective strainers; d) applying an electrical current to the security system to allow electric current to travel between the strainers through the conductive links.

15. A method as claimed in claim 14 wherein the length of material is tensioned by an appropriate movement by the tensioning device.

16. A method as claimed in claim 14 wherein step c) includes applying a fastener to a threadable portion of the attachment portion of the elongate insert, ensuring the conductive link is positioned between the fastener and the housing.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

(2) FIG. 1 shows the strainer according to one embodiment of the present invention;

(3) FIG. 2 shows an exploded view of the components of the strainer according to one embodiment of the present invention;

(4) FIG. 3 shows a view of the strainer and the washer according to one embodiment of the present invention;

(5) FIG. 4 shows different views of the tensioning device according to a second embodiment of the present invention;

(6) FIG. 5 shows a view of the conductive component according to one embodiment of the present invention;

(7) FIG. 6 shows a view of the conductive component according to a second embodiment of the present invention;

(8) FIG. 7 shows a cross-sectional view of the strainer according to one embodiment of the present invention; and

(9) FIG. 8 shows a use of the strainer in an electric fence according to one embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

(10) As shown generally in FIG. 1, the strainer (1) is in the form according to a particularly preferred embodiment of the present invention. The components of the strainer (1) are provided in FIG. 2 (exploded view). FIG. 8 shows a view of a multitude of strainers (1) mounted to posts (20) to form a security system.

(11) As shown in FIGS. 1 and 2, the strainer (1) is made substantially of plastic material except for the conductive component (11), the fastener (16), the conductive link (17) and the washer (25). The strainer (1) includes a housing with a head portion with rounded sides (21), rounded tips (22) and a box shaped backing portion (23).

(12) As depicted generally in FIGS. 1 and 2, the strainer includes a tensioning device in the form of a ratchet (2).

(13) As shown in FIG. 4, the ratchet has two wheels joined by a central portion (4). The ratchet (2) has an engagement portion configured as an aperture (5) which passes through the central portion (4) of the ratchet (2). As illustrated in FIG. 1, a length of material is provided as a wire (6), and is able to be positioned through the aperture (5). The central portion (4) is hollow with 6 sided walls. The hollow portion is accessible from both side of the ratchet (2).

(14) The ratchet wheels (3) each have a set of symmetrically shaped triangular teeth (7) that project outwards from the circumference of the ratchet wheels (3).

(15) The strainer (1) includes a locking mechanism configured as a pawl (8). This allows rotation of the ratchet (2) in one direction, but is able to prevent rotation of the ratchet (2) in the opposition direction. The locking ability of the pawl (8) is reversible such that locking in both directional movements is possible. This is achieved by rotating the pawl on its axle until the leading edge of the pawl (8) engages on the opposite side of the ratchet wheels (3). This may allow tensioning and locking of the wire (6) in either direction. The pawl (8) is positioned near the rounded tip (22) of the housing and is attached to the strainer (1) on a rotational axis point (10).

(16) As shown in FIG. 4 the hollow portion (4) has two elongate protrusions (27) opposing each other which run approximately half the length of the hollow central portion peripheral to the aperture (5)

(17) As shown in FIG. 3, the strainer preferably includes an optional washer (25) which is placed on the metal insert (11) adjacent to the housing. The washer (25) includes a protrusion (29) which is configured to engage with an aperture in the housing. The conductive link (17) if required, any wire link it retains and fastener (16) are then secured over the washer on the metal insert (11).

(18) As depicted in FIG. 5, the strainer (1) includes a conductive component in the form of a removable metal insert (11) that fits into the hollow central portion of the ratchet (2). The metal insert (11) is also displayed in FIGS. 1 and 2. The metal insert (11) has a first end configured as a six sided nut shaped head (12) with an aperture (13) passing through it.

(19) As shown in FIG. 5, the six sided nut shaped head has two elongate recesses (24) which are configured to engage with the elongate protrusions (27) in the hollow central portion of the ratchet (2).

(20) The aperture (13) is positioned such that when the metal insert (11) is positioned in the hollow central portion (4), it can align with the aperture (5) in the hollow central portion (4). The metal insert (11) has a thread (15) that is configured to interact with a fastener configured as a nut (16). The thread (15) is positioned on the metal insert (11) such that the thread (15) protrudes from the strainer (1).

(21) FIG. 6 shows an alternate configuration of the metal insert (11) without the elongate recesses (24).

(22) As shown in FIGS. 1 and 2 the strainer includes a metal conductive link (17) in the form of an elongate central arm (18) with an offset attachment point (19) at either end. The linking points (19) are both out of the vertical and horizontal planes of the central arm (18). The linking points (19) are in the shape of washers with a raised annular protrusion on one side (not shown). An attachment point (19) of a conductive link (17) is configured to fit over a thread (15) of the metal insert (11) which protrudes from the strainer (1). Fastening a nut (16) on the thread (15) of the metal insert (11) can then also fasten the conductive link (17) to the strainer to link two strainers together.

(23) The material used in all conductive elements in the present system is chosen to have the lowest galvanic corrosion potential when connected together. The wire (6) is made of alloy or high-tensile galvanised steel), the nut (16) and metal insert (11) are made of steel, (the nut is hot-dip or spun galvanised), and the conductive link (17) is made of either high-tensile galvanised wire, or punched and formed pre-galvanised metal).

(24) The wires may normally be one of the following types: 2.0 mm to 2.5 mm solid alloy wire, 2.0 mm to 2.5 mm galvanised high-tensile steel wire, 1.6 mm solid alloy wire, 1.6 mm galvanised high-tensile steel wire, 2.7 mm composite wire (i.e. 2.5 mm high-tensile steel wire with a heavy alloy coating).

(25) Alternatively all metal parts may be made from compatible stainless steel.

(26) FIG. 8 shows one example of how the current invention can be used to configure an electric fence as a security system. The metal conductive link links two strainers positioned downstream or upstream and which are separated by a middle strainer. In the configuration shown in FIG. 8, the live wire is connected at the ends so that it zigzags in as a continuous conductive path. This is so an electric pulse may be sent into the wire at one end and monitored for a cut wire at the other end.

(27) The conductive component is also used as a point of electrical contact for a lead out wire and anti-climb wires (not shown). The connections will be made preferably with a lug crimped on to the feed wire or with the feed wire attached directly to the conductive component via a fastener.

(28) The earth wires are all connected together so that there are redundant connections. This helps to ensure there will be a shock between any adjacent wire and an earth wire. Other configurations are available, for example two continuous live wires.

(29) Substantially any configuration may be achieved. Typically no more than two metal conductive links are connected to any strainer; however this is not essential.

(30) Preferred configurations are: Connecting every alternate wire for series circuits e.g. connecting first and third, second and fourth, fifth and seventh, sixth and eighth, etc. Connecting every alternate wire for parallel circuits e.g. first, third, fifth, seventh, and so on, all connected together. Connecting two adjacent wires e.g. connecting second and third wires. Connecting two wires that are three wires apart e.g. connecting first and fourth wires. Connecting wires that are more than three wires apart.

(31) Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the appended claims.