GB2307493A

GB2307493A - Fencing

Info

Publication number: GB2307493A
Application number: GB9623903A
Authority: GB
Inventors: Peter Attwood
Original assignee: FAIRMILE FENCING Ltd
Current assignee: FAIRMILE FENCING Ltd
Priority date: 1995-11-22
Filing date: 1996-11-18
Publication date: 1997-05-28
Anticipated expiration: 2016-11-18
Also published as: GB2307493B; ZA969735B; GB9523875D0; GB9623903D0

Abstract

Each pale (10) of palisade fencing has a concave cross-section to face the rails (11) and clamp-plates (13) each have hooked ends (14) to engage slots (12) in the sides of a pale from within, the ends (14) hooking over towards the intersected rail, which has a hole (16) for a security fastener (17, 18) which is capable of pulling the respective clamp-plate (13) towards the rail and causing the hooked ends (14) acting on the slots (12) to pull the edges (19) of the pale tight against the rail. Thus sideways removal of the pales (10) from the clamp-plates (13) is prevented, and the cross-sectional shape of the pales affords them great strength against levering attack as well as concealing the security fasteners (17, 18).

Description

FENCING This invention relates to steel fencing, more particularly palisade fencing in which vertical pales are attached to longitudinal rails.

Previously pale sections have been expected to meet both the criterion for bending strength at the centre and security of 'attachment' at the rails. This leads to inefficient design of the pale section and weak/vulnerable attachment to the rails.

The object of the present invention is, therefore, to provide pales designed to maximise bending strength with the most efficient use of material, and to provide means for connection of the pales to the rails designed to maximise strength with security against attack.

According to the present invention, palisade fencing comprises pales, rails, clamp-plates and security fasteners having the following features: the pales have a concave cross-section to face the rails, and each pale is provided at each rail-intersecting location with a pair of longitudinally extending slots one in each side of the pale; each clamp-plate fits within the concavity of a pale and has ends passing through the slots and hooked over towards the intersected rail, a hole (which may be screwthreaded) or a screw threaded stem being provided at the middle of the clamp-plate for location of the security fastener; the slots in the pales are wide enough to enable the clamp-plate ends to be passed through from within; the rails are provided at each pale-intersecting location with a hole for a security fastener;; and each security fastener is capable of pulling the respective clamp-plate towards the rail and causing the hooked ends of the clamp-plate acting on the slots in the pale to pull the edges of the pale tight against the rail.

The hooked ends of the clamp-plate engaged with the slots prevent sideways removal of the pale from the clamp plate, and the cross-sectional shape of each pale affords it great strength to withstand attack by attempting to pull or lever the pale off the clamp-plate or the clamp-plate off the security fastener. Each pale may have an arcuate cross-section, which may be nearly semi-circular, (but it may altematively be trapezoidal) and preferably has outward flanges along its edges to abut the rails. The use of the clamp plates through the slots in the sides of the pales enables a greater economical use of material in the design and forming of the pales.

The security fasteners are concealed within the pales and so protected against attack from outside the fence.

The clamp-plates are preferably made from high tensile steel and also preferably have a concave cross-section, which may be arcuate and may approach a quarter of a circle (but may alternatively be trapezoidal or rectangular), to face the rails within the pale cross-section, to afford the clamp-plates great rigidity that enables security fasteners of high strength to be used and for this high strength to be transmitted to the pales without deforming the pales.

The clamp-plates may be provided with square or round holes (which latter may be screwthreaded), or with screw threaded stems according to the type of security fastener employed.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front elevation of intersecting portions of a vertical pale and a horizontal rail of palisade fencing with a clamp-plate and security fastener securing them together; Figure 2 is a fragmentary horizontal section taken from the line II-II of Figure 1; Figure 3 is a perspective view of the clamp-plate shown in Figures 1 and 2; Figures 4 and 5 correspond to Figures 1 and 2 but show modifications to the pale and clamp-plate and also a different form of security fastener; Figure 6 corresponds to Figure 5 but shows further modified forms of pale and clamp-plate and also another form of security fastener; and Figure 7 is a vertical section through the clamp plate of Figure 6.

Figures 1 and 2 show a vertical pale 10 of substantially semicircular cross-section provided where it intersects a horizontal rail 11 with a pair of longitudinally extending slots 12 one in each side of the pale, a clamp-plate 13 (see also Figure 3) fitting within the concavity of the pale and having ends 14 passing through the slots and hooked over towards the intersected rail, a hole 15 being provided at the middle of the clamp-plate for location of a security fastener, the slots 12 being wide enough to enable the clamp-plate ends 14 to be passed through from within, and the rail also being provided with a hole 16 for the security fastener, which consists of a bolt 17 and a threaded cone 18 (initially attached at a shearing neck to a hexagon head 18A shown in chaindotted line) capable of pulling the clamp-plate 13 towards the rail and causing the hooked ends of the clamp-plate acting on the slots 12 to pull the edges 19 of the pale tight against the rail.

The hole 15 in the clamp-plate 13 is square and is engaged by a square portion 20 of the bolt 17 adjacent its head 21, to hold the bolt against rotation when the threaded cone 18 is screwed up tight e.g., by means of a spanner (not shown) until, at the correct torque, the neck shears to leave the cone 18 in place.

The hooked ends 14 of the clamp-plate 13 engaged with the slots 12 prevent sideways removal of the pale 10 from the clamp-plate, and the cross-sectional shape of the pale affords it great strength to withstand attack by attempting to pull or lever the pale off the clamp-plate or the clamp-plate off the security fastener.

In addition to being made of high tensile steel, the cross-section of the clamp-plate 13 approaches a quarter of a circle facing the rail 11 within the pale cross-section, to afford the clamp-plate great rigidity that enables the use of a high strength security fastener 17, 18 to be used and for this high strength to be transmitted to the pale without deforming it.

In Figures 4 and S, the pale 10 is provided, as preferred, with outward flanges 22 along its edges to abut the rail 11, yet still with an economical use of material in the forming of the pale with great strength because of the use of the clamp-plate 13 through the slots 12 in the sides of the pale.

It will also be seen in Figures 4 and 5 that a security bolt 23 passes through the hole 16 in the clamp-plate and then screws into a screw-threaded hole 24 in the clamp-plate, the head 25 of the bolt 23 left in place after shearing off at a neck of a hexagon drive head 25A engaged e.g.

by a spanner (not shown), tightening of the bolt pulling the clamp-plate towards the rail and bringing the hooked ends 14 of the clamp-plate into engagement with the flanges 22 along the edges of the pale. Other types of security fasteners may of course be used, possibly requiring a special wrench.

In Figure 6 the pale 10 has a trapezoidal cross-section with flanges 22 along its edges to abut the rail 11, and the clamp-plate 13 has an open rectangular cross-section (see Figure 7) which is uniform over a middle portion providing straight edges 26 which are pulled into contact with the rail 11 by a security fastener having a head 27 and a stem 28 passing through clearance holes 29, 30, in the clamp-plate and the rail respectively, the stem being provided with a grooved-andribbed portion 31 within a collar 32 that is cold-swaged on to the stem by a tool (not shown) also used to pull on the stem through a portion (not shown) joined to the portion 32 by a neck 33 that is broken when swaging of the collar has been effected.

Claims

1. Palisade fencing comprising pales, rails, clamp-plates and security fasteners having the following features: the pales have a concave cross-section to face the rails, and each pale is provided at each rail-intersecting location with a pair of longitudinally extending slots one in each side of the pale; each clamp-plate fits within the concavity of a pale and has ends passing through the slots and hooked over towards the intersected rail, a hole (which may be screwthreaded) or a screw threaded stem being provided at the middle of the clamp-plate for location of the security fastener; the slots in the pales are wide enough to enable the clamp-plate ends to be passed through from within; the rails are provided at each pale-intersecting location with a hole for a security fastener;; and each security fastener is capable of pulling the respective clamp-plate towards the rail and causing the hooked ends of the clamp-plate acting on the slots in the pale to pull the edges of the pale tight against the rail.

2. Palisade fencing as in Claim 1, wherein each pale has an arcuate cross-section.

3. Palisade fencing as in Claim 2, wherein the pale cross-section is nearly semi-circular.

4. Palisade fencing as in Claim 1, wherein each pale has a trapezoidal cross-section.

5. Palisade fencing as in any one of Claims 2 to 4, wherein each pale has outward flanges along its edges to abut the rails.

6. Palisade fencing as in any one of Claims 1 to 5, wherein the clamp-plates are made from high tensile steel.

7. Palisade fencing as in Claim 6, wherein the clamp-plates have a concave cross-section.

8. Palisade fencing as in Claim 7, wherein the clamp plate cross-section is arcuate.

9. Palisade fencing as in Claim 8, wherein the clamp plate cross-section approaches a quarter of a circle.

10. Palisade fencing as in Claim 7, wherein the clamp plate cross-section is trapezoidal.

11. Palisade fencing as in Claim 7, wherein the clamp plate cross-section is rectangular.

12. Palisade fencing as in any one of Claims 1 to 11, wherein the clamp-plates are provided with square holes.

13. Palisade fencing as in any one of Claims 1 to 11, wherein the clamp-plates are provided with round holes.

14. Palisade fencing as in Claim 13, wherein the holes are screwthreaded.

15. Palisade fencing as in any one of Claims 1 to 11, wherein the clamp-plates are provided with screwthreaded stems.

16. Palisade fencing comprising pales, rails, clamp-plates and security fasteners conjoined, substantially as hereinbefore described with reference to Figures 1 to 3 or Figures 4 and 5 or Figures 6 and 7 of the accompanying drawings.