GB2391560A

GB2391560A - Fence panel clamp

Info

Publication number: GB2391560A
Application number: GB0218378A
Authority: GB
Inventors: Stuart Scholley
Original assignee: ZND UK Ltd
Current assignee: ZND UK Ltd
Priority date: 2002-08-07
Filing date: 2002-08-07
Publication date: 2004-02-11
Anticipated expiration: 2022-08-07
Also published as: GB0218378D0; GB2391560B

Abstract

A fence panel clamping device, used to hold adjacent panels together, comprises a pair of connecting pieces 701, 702 which are connected together using a removable fastening means, such as a coach bolt 703 and nut 605. The connecting pieces have a channel shaped cross section along their length which may be U-shaped, and pole-receiving curved portions at each end. The device is designed so that the distance between the points of contact between the fastening means and the connecting pieces is larger than the diameter of the poles (602, 603, Fig 6), which makes the device stronger and less likely to deform. The connecting pieces may be strengthened using a central reinforcing web 710. The side portions 706, 702 may be perpendicular to the surface of the main portion 07, or alternatively at an obtuse angle for ease of manufacture.

Description

Temporary Fencing Coupler Field of the Invention

The present invention relates to linking fencing panels together in a temporary fencing system.

Introduction

Temporary fencing systems are used In many situations, for example at concerts, particularly large festivals, at fairgrounds, near roadworks and on to construction sites. In most of these situations a certain standard of fencing is required, and this is particularly tnue in the construction industry, where Health and Safety Executive recommendations and guidance notes exist regarding the level of protection that must be provided to a site in order to prevent people, especially children, from trespassing.

Because of this, traditional temporary fencing such as timber hoarding and chain-link fencing is no longer used and standard fencing systems now use panels of framed weld mesh or of solid metal which are extremely durable and difficult to breach. However, the couplers holding these panels together often deform when over-tightened, thus lessening the overall zo strength of the fencing system. There is therefore a need for a more rigid design of coupler which will keep its shape and therefore its strength during use. Brief Summary of the Invention

5 According to a first aspect of the invention, there is provided a fence panel clamping device comprising two connecting pieces and a removeable

fastening means to fasten the connecting pieces together wherein at least one of said connecting pieces has a channel-shaped cross-section along its length, such that in use each end of each connecting piece locates around a pole and the distance between the points of contact between the 5 fastening means and the connecting pieces is larger than the diameter of the poles.

Brief Description of the Several Views of the Drawings

Figure 1 illustrates a construction site on which a temporary fencing to system is being used.

Figure 1A illustrates an alternative form of fencing system.

Figure 2 shows a prior art coupler.:

Figure 3 shows a side view of the coupler shown in Figure 2.

Figure 4 shows a cross-section of the coupler along the line A-A 15 shown in Figure 3.

Figure 5 shows a cross-section of the coupler shown in Figure 3 being I deformed. Figure 6 illustrates a coupler according to the present invention in use.

Figure 7 shows an exploded view of the coupler shown in Figure 6.

20 Figure 8 shows a side view of the coupler shown in Figure 6.

Figure 9 shows a cross-section of the coupler along a line shown in; Figure 8.

Figure 10 illustrates a coupler in accordance with an alternative embodiment of the present invention.

25 Figure 11 shows an exploded view of the coupler shown in Figure 10.

Figure 12 illustrates the angle between the main and side portions of the coupler shown in Figure 10.

Written Description of the Best Mode for Carrying Out the Invention

Figure 1 Figure 1 illustrates a typical construction site where workmen are engaged in building works. The site is protected by temporary fencing system 101 which consists of three temporary fence panels 102, 103 and to 104, concrete feet 105 and 106, and couplers 107, 108, 109 and 110.

Panels 102, 103 and 104 each comprise a rectangular frame with tubular uprights, with sturdy wire mesh contained within. Couplers 107 to 110 are designed to fit around these tubular uprights and must be fastened tightly in order to maintain the overall strength of fencing system 101.

Figure 1A shows the view from the back of a temporary hoarding system 111, which is a more robust and secure type of fencing system. It I comprises hoarding panels 112, 113 and 114, concrete feet 115 and 116 and couplers 117, 118, 119 and 120. Each hoarding panel is made of steel, corrugated to add strength, and has a tubular shape at each end to no accommodate the couplers. While this type of fencing is much stronger and gives more privacy than that illustrated in Figure 1, the solid panels are; more susceptible to the wind than wire mesh panels. Supports 121, 122, 123 and 124, located in concrete feet 125 and 126, brace the panels and help prevent them from being blown down. However, the movement of the as panels caused by wind means that it is even more necessary that couplers 117 to 120 are fastened as tightly as possible.

Other designs of temporary fencing differ according to manufacturer and specific use, but most are a variation on this design and in particular the panels usually include a frame with tubular uprights. For this reason the same design of coupler can be used for nearly all types of fencing system.

Figure 2 The standard coupler now in use is shown in Figure 2. Coupler 201 consists of two connecting pieces 202 and 203, each of which forms a rounded shape at each end configured to locate around poles 204 and 205.

to Bolt 206 is passed through holes in each of the connecting pieces and is secured using washer 207 and nut 208. When bolt 208 is tightened coupler 201 securely holds poles 204 and 205 at a set distance from each other.

Clearly, in order to reach Health and Safety standards nut 208 must be as tight as possible in order to avoid coupler 201 becoming loose or being removeable by hand. Additionally, in the system shown in Figure 1A any looseness in the couplers will decrease the system's resistance to high winds. However, if nut 208 is over-tightened one or both of connecting pieces 202 and 203 may deform.

20 Figure 3 Figure 3 shows a side view of coupler 201. Previous improvements to prevent connecting piece 203 deforming when nut 208 is over-tightened are the inclusion of ribs 301 and 302 and the folding inwards of portions 303 and 304. Connecting piece 202 is identical in design to piece 203 and 2s thus includes similar ribs and folded portions.

Figure 4 Figure 4 shows a cross section of coupler 201 along the line A-A.

The curved ends of connecting pieces 202 and 203 are located around poles 204 and 205, and bolt 206, washer 207 and nut 208 hold the two connecting pieces together. Ribs 301 and 302 on connecting piece 203 and 401 and 402 on connecting piece 202 give strength to the end portions, while folded portions 304 on connecting piece 203 and 403 on connecting piece 202 give strength to the central parts.

lo Figure 5 Figure 5 illustrates how although these features provide added rigidity they still do not stop the connecting pieces deforming if nut 208 is over-tightened. As the nut is tightened connecting pieces 202 and 203 are pulled together and thus each exerts an active force on the poles in the s directions shown by arrows 501 and 502 respectively. Pole 204 exerts a reactive force on the connecting pieces in the directions shown by arrows 503. Similarly, pole 205 exerts a reactive force on the connecting pieces in the directions shown by arrows 504. If nut 208 is tightened by the right amount these opposing forces result in the poles being held securely by the zo coupler. However, if nut 208 is over- tightened either the poles or the coupler must give and the poles are, of necessity, more rigid than the connecting pieces. Hence connecting pieces 203 and 204 bend inwards around the bolt and at the points indicated by arrows 505, 506, 507 and 508. This has 2s the effect of actually moving the ends of the connecting pieces away from the poles, thus loosening the grip of the coupler. Since a workman often

does not know i! he is over-tightening the nut until deformation starts to occur it is inevitable that couplers are frequently left slightly loose through under-tightening and also that they must often be discarded through over tightening. Figure 6 Figure 6 illustrates a coupler in accordance with the present invention. Fencing panels 102 and 103 include adjacent poles 602 and 603 respectively, and workman 601 is connecting these poles using coupler to 107. This coupler is far stronger than the traditional design, which allows workman 601 to use spanner 604 to tighten nut 605 to the limit of his strength without damaging any part of the fencing system.

Figure 7 Figure 7 shows an exploded view of coupler 107. It comprises connecting pieces 701 and 702, which are identical in design save that piece 701 includes a square hole while piece 702 includes a round hole.

The fastening means for this coupler comprises coach bolt 703, which passes through connecting pieces 701 and 702 and washer 704, and nut so 605 which secures it. Coach bolt 703 locates within the square hole in piece 701, thus preventing it from turning when nut 605 is tightened. In an alternative embodiment (not shown) both pieces can contain a square hole.

Connecting piece 701 comprises a main portion 705 and two side portions 706 and 707 which are substantially perpendicular to the surface 25 of main portion 705, thus forming a square-bottomed U-shape.

At one end of side portion 707 there is defined an arc of a circle 708 into which pole 602 locates. At the other end is arc 709 into which pole 603 locates. Side portion 706 has similar arcs. In this way each end of each connecting piece forms the complementary shape of the respective pole. If 5 differently shaped or sized poles are used then the ends of the connecting pieces form the respective complementary shapes.

At the centre of side portion 707 is a central reinforcing web 710 extending from dotted line 711 away from the main portion. Dotted line 711 is defined as extending from the point of arc 708 which is closest to the to main portion to the corresponding point of arc 709, and would be defined similarly if a different complementary shape were used. Side portion 706 has a similar web. These webs have the effect of forming a deeper channel shape in the central part of each connecting piece.

Connecting piece 702 is shaped in a similar way. Hence both pieces 5 have a channel-shaped cross section along their length, where the channel shape is a square-bottomed U-shape, with shapes at each end complementary to the poles and reinforcing webs on their side portions.

Each connecting piece is clip pressed and formed from 2.5 mm thick mild steel, although other manufacturing methods or materials may be used.

Figure 8 & 9 Figure 8 illustrates a side view of coupler 107, and Figure 9 shows the cross section view along line B-B. This shows how when nut 605 is tightened onto bolt 703 connecting pieces 701 and 702 exert, along their 25 respective side portions, an active force on poles 602 and 603, as shown by sets of arrows 901 and 902 respectively. Poles 602 and 603 exert

reactive forces on the connecting pieces as shown by sets of arrows 903 and 904 respectively.

Because the forces are exerted along the side portions rather than, as in the prior art, directly from the main portion onto the pole, the overall

5 structure is stronger. Hence the channel shape of the connecting pieces gives far more rigidity than that given by the flat structure of the prior art

coupler. The reinforcing webs on each side portion also add rigidity because the side portions virtually enclose the poles. In this way the opposing forces to are distributed almost uniformly around the circumference of the poles, and thus there is much less pressure on the danger points indicated by arrows 91 1, 912, 913 and 914. Also, in order for the connecting pieces to buckle at danger points 911 to 914 it would be necessary for deformation to occur on the reinforcing webs. For example, for the main portion of piece 701 to bend around point 911 it would first be necessary for buckling to occur in the section indicated by circle 915. This again has the effect of distributing the pressure more evenly.

Additionally, the distance between the head of bolt 703 and nut 605 is larger than the diameter of each of poles 602 and 603. Therefore the 20 distance between the points of contact between the fastening means and the connecting pieces is greater than the diameter of the poles, meaning that the force exerted by the fastening means on the connecting means pushes the connecting means onto the poles. In other prior art couplers

(not shown) the connecting pieces curve towards each other between the 25 poles, and so the distance between the points of contact between the fastening means and the connecting means is smaller than the diameter of

the poles, meaning that the force exerted by the fastening means pulls the connecting means onto the poles. This puts even more pressure on the danger points where the connecting pieces meet the poles.

5 Figure 10 Figure 10 illustrates an alternative embodiment of the invention. In some manufacturing methods, it is difficult to make an item in which the sides are perpendicular to the main portion. For this reason, coupler 1001 comprises two connecting pieces 1002 and 1003 in which the side portions to are at an angle greater than ninety degrees to the main portions. There is a slight reduction in robustness in this design since when nut 1106 is tightened the forces exerted are not parallel with the side portions, but it is still far stronger than the prior art coupler 201.

Figure 1 1 Figure 11 shows an exploded view of coupler 1001. Connecting piece 1002 comprises main portion 1101 and side portions 1102 and 1103, which are at a constant angle to main portion 1101 as will be described in Figure 12. Connecting piece 1003 is of an identical design except that, as 20 before, piece 1002 contains a square hole while piece 1003 contains a round hole, although as before in an alternative embodiment (not shown) both pieces may contain a square hole. The two connecting pieces are joined together by bolt 1104, washer 1105 and nut 1106 in the same way as for coupler 107.

25 Each end of connecting piece 1002 is designed in a complementary shape to pole 602 or 603, ie so that it locates around a tubular pole of the

correct size. Connecting piece 1003 is similarly shaped. When couplers are required for differently sized or shaped poles the ends form a complementary shape. Each side portion also includes a reinforcing web.

5 Figure 12 Figure 12 shows connecting piece 1003. At point 1201 on the fold line between main portion 1001 and side portion 1105, a tangent to the fold line at that point 1202 is defined. A normal 1203 to tangent 1202 can be defined parallel to main portion 1101, and similarly a normal 1204 to to tangent 1202 can be defined parallel to side portion 1102. In a similar fashion, at point 1211 a tangent 1212 and two normals to that tangent 1213 and 1214 can be defined. The angle between both sets of normals is identical and this is true for any point along the fold line between main portion 1001 and side portion 1102. The same is true for the fold line between end portion 1001 and side portion 1103. In this way, side portions 1102 and 1103 are at a constant angle to end portion 1101. In this embodiment that angle is approximately fifty degrees but angles up to fifty five degrees may be used without substantial loss of rigidity.

Hence in this embodiment each connecting piece has a channel 20 shaped cross-section along its length, where the channel shape is a U shape with sloping sides. In other embodiments (not shown) the channel shape may be other shapes and may vary along the length of the connecting pieces.

Claims

1. A fence panel clamping device comprising two connecting pieces and a removeable fastening means to fasten the connecting pieces together wherein at least one of said connecting pieces has a channel-

shaped cross-section along its length, such that in use each end of each connecting piece locates around a pole and the distance between the points of contact between the fastening means and the connecting pieces is larger than the diameter of the poles.

2. A fence panel clamping device as claimed in claim 1, wherein each side portion of said channel-shaped connecting piece comprises a central reinforcing web.

s

3. A fence panel clamping device as claimed in either of claims 1 or 2, wherein the channel-shaped cross-section is U-shaped.

4. A fence panel clamping device as claimed in claim 3, wherein said Ushape is square-bottomed.

5. A fence panel clamping device as claimed in claim 3, wherein said Ushape has sloping sides.

6. A fence panel clamping device as claimed in any of claims 1 z5 to 5, wherein said removeable fastening means comprises a nut and bolt.

7. A fence panel clamping device comprising two connecting pieces and a removeable fastening means to fasten the connecting pieces together wherein at least one of said connecting pieces has a square-

bottomed U-shaped cross-section along its length and each side portion of said connecting piece comprises a reinforcing web, such that in use each end of each connecting piece locates around a pole and the distance between the points of contact between the fastening means and the connecting pieces is larger than the diameter of the poles.

8. A fence panel clamping device substantially as herein described with reference to either Figures 6 to 10 or Figures 11 and 12.