GB2273518A - Attachment members for substantially rigid mesh elements - Google Patents

Abstract

An attachment member for an element of substantially rigid mesh such as a scaffolding guard comprises a stem (5) and an attachment portion such as a hook (6), an eye or a spike, the stem being substantially more rigid than strands of the mesh and of length sufficient to extend perpendicularly across at least three successive strands of the mesh. The stem has on one side and spaced from its end remote from the attachment portion a distance at least greater than the pitch of the mesh a notch (7) capable of snug lateral engagement with a strand of the mesh and positioned so that when so engaged with a strand it holds the attachment portion in an operative position relative to the element. The end (9) of the stem is designed to engage a strand of the mesh so as to urge the notch towards a strand. For example it may be formed into a securing hook. <IMAGE>

Description

ATTACHMENT MEMBERS FOR SUBSTANTIALLY RIGID MESH ELEMENTS Elements such as guards, screens, fencing panels and parts of cages are commonly constructed from substantially rigid mesh material, for example that comprising a lattice of strands such as metal wires or strands of plastics material welded together at their crossing points. For securing such elements in position, for example securing them to other objects or to each other it is usually necessary to provide them with attachment members. An example is a scaffolding guard, used to restrain or prevent tools, pieces of masonry, building materials or workers falling from scaffolding platforms. A scaffolding guard comprises a screen of substantially rigid welded wire mesh which is hung from a substantially horizontal scaffolding tube.Attachment members are required to enable it to be hung and commonly comprise hooked metal rods which are welded to wires of the mesh. The hooked parts of the rods, of course, lie in planes substantially perpendicular to the plane of the guard. Therefore they obstruct close stacking of guards which are not in use and they are likely to be bent or damaged when guards are stacked or being handled during the erection or dismantling of scaffolding.

British Patent Specification No. 2 137 275 B describes a scaffolding guard of longitudinal and transverse strands welded together in a generally rectangular configuration having a plurality of hooked attachment members mounted for movement between operative positions in which the hook portions extend generally transversely of the screen, enabling the guard to be hooked onto scaffolding, and inoperative positions in which the hook potions lie generally co-planar within the screen.In the embodiment described and illustrated in the said Specification the hook members have elongated stems which are enmeshed in the screen bv being interwoven with transverse strands, successive strands in one longitudinal column of the screen being shaped into bows directed to opposite sides of the screen so as to define passages through which the stems extend. Each member has means at the end of its stem opposite to its hook portion for limiting longitudinal movement of the member relative to the screen, such as a flattened or bent part of the stem. With this arrangement, the hook portions of the attachment members on guards which are not in use can be moved into their inoperative positions so that they do not obstruct close stacking of the guards.

However, when the means for limiting longitudinal movement of an attachment member relative to the screen is a bent part of the stem it can prevent removal of the stem from the screen. Thus if the hook portion is bent or broken it is not easy to replace the attachment member Furthermore, the shaping of successive strands of the mesh to define passages through which the stems extend requires an additional manufacturing step which increases the cost of a guard.

According to this invention an attachment member for an element of substantially rigid mesh comprises a stem and an attachment portion, the stem being substantially stiffer than strands of the mesh with which it is intended to be used, of length sufficient to extend substantially perpendicularly across at least three successive parallel strands of the mesh and having on one side, adjacent to the attachment portion, a part for lateral engagement with a first strand of the mesh and on the other side, spaced from the end of the stem remote from the attachment portion a distance greater than a pitch of the mesh a notch capable of snug lateral engagement with the next parallel strand of the mesh and designed so that when so engaged it will hold the attachment portion in an operative position relative to the element, the said end of the stem remote from the attachment portion being designed to engage a subsequent parallel strand of the mesh and thereby to urge the notch towards the said next strand.

By a pitch of the mesh we mean the distance between adjacent parallel strands. Usually the pitch is equal for all parallel strands of a mesh, but that is not essential. If the pitch is variable then the said distances along the stem will be related to the pitch or pitches between the strands which are to be engaged by the said part, the notch and the end of the stem.

The attachment portion may be of any desired shape, such as a hook, an eye or a spike suitable for attaching or securing the element as required Indeed, it may be similar or identical to the stem, either aligned with or inclined to the stem, for joining together two elements of substantially rigid mesh. Using such attachmewnt members it is possible to construct a cage or enclosure comprising several elements of substantially rigid mesh. For example show cages for animals or birds can readily be constructed and with attachment members of which the attachment portion is a spike a cage or enclosure could be fastened to the ground.

An attachment member as described above having only one notch in its stem is mounted on an element of substantially rigid mesh by inserting the end of its stem to one side of a first strand of the mesh element, to the other side of the next parallel strand and then the end of its stem is engaged with the said subsequent parallel strand so that its notch is urged towards and engages the said next strand. If the end of the stem is substantially straight it will be engaged with the subsequent parallel strand simply by being passed to the said one side of that strand, thereby urging the notch towards the said next strand.However, such engagement may not be very secure and for improved engagement the end of the stem may be formed into a securing hook of internal width sufficient to receive the next parallel strand Preferably an attachment member as described has two or more notches on the said other side of its stem to provide more secure mounting on the mesh element. Conveniently, three notches are provided, positioned to engage three adjacent parallel strands of the mesh element.

The said first strand will usually be one forming the edge of the mesh element, but it is possible to mount an appropriately designed attachment member with certain kinds of attachment portion in positions away from the edges of the element.

An attachment member as described may be mounted quickly and easily on an element of substantially rigid mesh at any desired position around its edge, or under certain circumstances in other positions, and may just as easily be removed. No special shaping of strands of the mesh is required and a damaged or bent attachment member can readily be replaced When the attachment members are removed, elements may be stacked closely together without interference.

Embodiments of the invention are illustrated by the accompanying drawings, in which: Figure 1 is an elevation of a comer part of a scaffolding guard of welded wire mesh, with a first attachment member partially mounted on the guard and a second, similar, attachment member fully mounted in position on the guard, Figure 2 is a side elevation of a different attachment member, Figures 3 to 5 are sections through a part of a similar scaffolding guard, showing three stages in the mounting of the attachment member shown in Figure 2 on the guard.

In Figure 1 an attachment member 1 at the left hand side of the drawing is partially mounted on the guard and an identical attachment member 2 at the right hand side is filly mounted in position on the guard.

The scaffolding guard shown in part in Figure 1 is a rectangular piece of substantially rigid welded wire mesh comprising a series of parallel uniformly spaced wires 3 which are vertical in the drawing crossed by and welded to a similar series of spaced wires 4a to 4h, perpendicular to the wires 3 and horizontal in the drawing. Each attachment member 1, 2 is formed from wire about twice the thickness of and substantially stiffer than the wires 3 and 4 and comprises a stem 5 and an attachment portion 6 in the form of a hook shaped to fit over a scaffolding tube.The surface of the first part of the stem S on the same side as the attachment portion 6 is intended to engage the first wire 4a of the mesh guard and the remainder of the stem 5 is formed by bending with three notches 7 all opening on one side of the stem, of a size such as to receive laterally a wire 4 and spaced apart equally to the pitch (spacing) of the wires 4. The end of the stem opposite to the attachment portion 6 is bent back on itself at a distance equal to the pitch from the adjacent notch 7 to form a securing hook 8 of internal width suitable to fit over a wire 4.

The first attachment member 1, as mentioned, is partially mounted on the guard. As shown, it is disposed with its notches 7 facing towards the left in the drawing and its stem 5 has been inserted from the top to the front side of the first or edge horizontal wire 4a, then to the rear side of the subsequem three horizontal wires 4b, 4c, 4d and to the front side of the next horizontal wire 4e. The attachment member 1 has been tumed so that its hooks 6 and 8 lie in a plane more or less parallel to the plane of the mesh so that this insertion can be performed easily, with slight elastic distortion of the respective horizontal wires rearwardly and forwardly of their normal dispositions in the plane of the mesh. As shown, insertion is almost completed, with the end 9 of the securing hook 8 above the horizontal wire 4e.

To complete the mounting of the first attachment member 1, it would be pushed further downwardly until the end 9 of the securing hook cleared the horizontal wire 4e and the stem 5 could be rotated to cause the end 9 to enter the mesh aperture 10 below the wire 4e and the notches 7 to face the plane of the mesh. The attachment member would then be drawn upwardly, engaging its securing hook 8 with the horizontal wire 4e until the notches 7 were aligned with and entered by the horizontal wires 4b to 4d, which would thereby recover elastically substantially their original disposition in the plane of the mesh. It would then be in a similar position in relation to the guard to that of the second attachment member 2.The snug engagement of the horizontal wires 4b to 4d with the notches 7 and the engagement of the securing hook with the horizontal wire 4e hold the stem 5 firmly in position with its attachment portion 6 appropriately disposed for use, the latter engagement also securing the attachment member against upward movement relative to the guard, or preventing the guard from falling off the attachment member when its attachment portion 6 is hooked over a scaffolding tube or the like.

The mounting of an attachment member as described can be achieved by hand in a matter of seconds and the attachment member can be removed just as easily. It is simply pushed downwardly until the end 9 of its securing hook 8 clears the horizontal wire 4e, rotated through approximately 90 and pulled upwardly out of the guard. Thus if guards are to be stacked when not in use the attachment members can be removed. A bent or damaged attachment member, or one that is inappropriately shaped for a particular application, can readily be replaced with another.

For a smaller and/or lighter element than the scaffolding guard shown in the drawing the stem of an attachment member may have only one or two notches like the notches 7 and then on insertion it would be passed to the rear side of only one or two horizontal wires. Likewise for a heavier or larger mesh element a stem with more notches might be required and would be passed to the rear side of more horizontal wires.

For a lightweight element of substantially rigid mesh or one which is to be used in a situation in which unintentional withdrawal of the stem of an attachment member is unlikely or impossible, the securing hook 8 may be omitted, the stem just being of sufficient length beyond the notch most remote from its attachment portion to engage the side of the parallel wire next to the one engaged by the said notch The attachment member 11 shown in Figure 2 is generally similar to the attachment members 1 and 2 shown in Figure 1, comprising an attachment portion 12 in the form of a hook and a stem 13 of wire that is substantially stiffer than the wires of the mesh with which it is to be used, formed by bending with three notches 14 similar to the notches 7 and having the end of the stem 13 formed into a securing hook 15 for receiving a wire of the mesh.It differs from the attachment members 1 and 2 only in that the securing hook 15 opens on the same side of the stem as the notches 14. This avoids the need to interweave the stem with the strands of the mesh so it is no longer necessary to rotate the securing hook into the plane of the guard in order to insert it. Also in this embodiment the parts 16, 17 of the stem forming the sides of the securing hook 15 (in particular the part 17 forming the outer side) are inclined to the remainder of the stem 13 so that the closed end of the hook is on the side of the central axis 18 of the stem opposite to the mouths of the notches 14. As will be seen, this helps to urge the notches towards the wires of the mesh so that less distortion of the mesh occurs during mounting of the attachment member and less force is needed for mounting.

Figures 3 to S show the mounting of the attachment member 11 on a scaffolding guard, part of which is shown in cross section, comprising parallel wires 19a to 19i welded to perpendicular wires 20. The attachment member is shown being mounted in a middle position away from the edge of the guard rather than at its edge, though of course it could equally easily be mounted at an edge.

As shown in Figure 3, the stem 13 is first inserted through an appropriately-positioned aperture of the mesh, in this case the aperture between wires 19d and 19e, until its notch 14 nearest to the attachment portion 12 is well past the wire 19e. Then, as shown in Figure 4, the end of the stem is swung back towards the guard, as indicated by the arrow A, until its parts adjacent to the notches 14 contact respectively the wires 19e, 19f, 19g and 19h. This causes some elastic bending of the guard in the region of the said aperture, in particular of the wires 19b, 1 9c and 19d. It will be noted that at this stage the mouth of the searing hook 15 is close to and directed towards the wire 19h.The member is then pulled upwardly as indicated by the arrow B whilst holding its stem 13 against the wire 19h as indicated by arrrrw C so that the securing hook 15 receives the wire 19h. The engagement of the wire 19h with the inclined part 17 of the securing hook urges the notches 14 towards the wires 19e, 19f and 19g until the wire 19h occupies the closed end of the securing hook, when each notch receives a respective wire 19e, l9f and 19g as shown in Figure 5, holding the attachment portion 12 securely at right angles to the plane of the guard for hooking over a scaffold pole as required The elastic bending of the wires of the guard is partly relaxed during this final movement, but is still sufficient to hold the attachment securely in the operative position shown in Figure 5..

To remove the attachment member 11 from the guard it is simply pushed downwardly (in the position shown in Figure 5) until the securing hook 15 clears the wire 19h, whereupon the stem 13 can be withdrawn from the aperture.

The limiting factors determining whether an attachment member can be mounted away from the edge of a mesh element or only at its edge are the shape of the stem and of the attachment portion. For example if the attachment portion 12 was oppositely directed, as shown in chain dotted lines at 12a in Figure 3, it would foul the guard if the stem was inserted through an aperture more than two pitches from an edge.

For joining two substantially rigid mesh elements together an attachment member may have an attachment portion which is similar to its stem, with similar notch or notches, and aligned with the stem or inclined thereto.

Instead of an attachment member being formed from wire with a notch or notches formed by bending, it may be of metal sheet or rod and the notch or notches could be formed by machining or any other convenient method. Alternatively an attachment member could be moulded in plastics material with the notch or notches already formed in its stem.

Claims (13)

1. An attachment member for an element of substantially rigid mesh comprising a stem and an attachment portion, the stem being substantially stiffer than strands of the mesh with which it is intended to be used, of length sufficient to extend substantially perpendicularly across at least three successive parallel strands of the mesh and having on one side, adjacent to the attachment portion, a part for lateral engagement with a first strand of the mesh and on the other side, spaced from the end of the stem remote from the attachment portion a distance greater than a pitch of the mesh a notch capable of snug lateral engagement with the next parallel strand of the mesh and designed so that when so engaged it will hold the attachment portion in an operative position relative to the element, the said end of the stem remote from the attachment portion being designed to engage a subsequent parallel strand of the mesh and thereby to urge the notch towards the said next strand.

2. An attachment member as claimed in Claim 1 whereof an end part of the stem is bent back on itself at a point spaced from the ndch a distance substantially equal to the spacing between adjacent strands of the mesh to form a securing hook for receiving a strand.

3. An attachment member as claimed in Claim 2 wherein the securing hook opens towards the side of the stem opposite to the notch.

4. An attachment member as claimed in Claim 2 wherein the securing hook opens towards the same side of the stem as the notch.

5. An attachment member as claimed in Claim 4 wherein the part of the stem forming the outer side of the securing hook is inclined to the stem so that it will be engaged by a strand received in the securing hook and produce a reaction urging the notch towards the said next strand.

6. An attachment member as claimed in any of Claims 1 to 5 whereof the stem has two or more notches on the said one side, spaced substantially equally to pitches of the mesh.

7. An attachment member as claimed in any preceding claim whereof the attachment portion is a hook, an eye, a spike or a portion similar to the stem.

8. An attachment member for an element of substantially rigid mesh, substantially as hereinbefore described with reference to and as fflustrated by Figure 1 or Figures 2 to 5 of the accompanying drawings.

9. The combination of an attachment member as claimed in any preceding claim and an element of substantially rigid mesh.

10. A scaffolding guard comprising an element of substantially rigid mesh having mounted on it an attachment member as claimed in any preceding claim.

11. A scaffolding guard substantially as hereinbefore described with reference to and as illustrated by Figure 1 or Figures 2 to 5 of the accompanying drawings.

12. An attachment member as claimed in any of Claims 1 to 6 wherein the attachment portion is similar to the stem, for engaging a second element of substantially rigid mesh.

13. An assembly of elements of substantially frigid mesh joined by attachment members as claimed in Claim 12.