GB2520168A - Structural anchor - Google Patents

Abstract

An anchor arrangement 1for mounting to a membrane skin of a structure has an anchor mounting bracket 2 includes a mounting flange 3 provided with one or more fixing apertures 4 and a raised section 5 projecting from the flange. The raised section 5 includes a mounting seat (6, Figure 4) for a bearing element 8. The bearing element 8 is seated on the mounting seat of the mounting bracket. The bearing element includes a bearing surface provided on an opposed side to the mounting seat of the mounting bracket. A load member 10 for attachment to a line is provided. The load member bears against the bearing surface of the bearing element and is rotatably mounted.

Description

Structural Anchor This invention relates generally to an anchor arrangement for anchoring to a structure such as a building roof.

More particularly, but not exclusively, the invention relates to an anchor for anchoring to a membrane skin of a structure such as a membrane roof structure. More specifically still the anchor arrangement is for use in working at height systems such as fall arrest systems, abseil systems or window washer cradle or other descender systems.

The invention relates to an anchor that is particularly suited to load bearing applications on such structures, where loads are only present intermittently or occasionally. For example abseil craWes for inspections or window cleaning on buildings are relatively infrequently used, but require secure anchor mountings for use. Typically secure anchors need to be mounted directly to the steel framework structure to which the membrane skin roof or wall panels are secured. Mounting of anchors directly to the membrane skin cladding is not generally advised as this would typically result in damage/deformation of the membrane skin panel in the event of an applied load.

An improved arrangement has now been devised.

According to the present invention, there is provided an anchor arrangement for mounting to a membrane skin of a structure, the anchor arrangement comprising: an anchor niounting bracket including a mounting flange provided with one or more fixing apertures and a raised section projecting from the flange. the raised section including a mounting seat for a hearing element; a bearing element seated on the mounting seat of the mounting bracket, the bearing element including a bearing surface provided on an opposed side to the mounting seat of the mounting bracket; a load member for attachment to a line; the toad member hearing against the bearing surface of the bearing element and being rotatably mounted.

The mounting seat preferably includes a securing formation and the hearing element includes a securing formation aligned with the mounting seat securing formation. The securing formations comprise apertures arranged to receive a securing bolt or shaft to extend through.

In certain embodinients. it may he preferred that the arrangement includes a bush element around which thc load member is arranged to rotate. In such an embodiment thc bush element is arranged to clamp against the bearing element.

In certain emhodiments it is preferred that the hearing arrangement is held against rotation.

It is generally preferred that the bearing element is of greater material thickness than the material thickness of the mounting seat of the mounting bracket. Beneficially the bearing element is of approximately twice the material thickness of the material thickness of the mounting seat of the mounting bracket.

It is preferred that the hearing element is of stainless steel and 5mm or greater in thickness.

It is preferred that the material of the mounting bracket is of pressed stainless steel plate of approximately 2mm to 5mm.

It is preferred that the mounting seat is substantially planar, preferably being substantially circular.

It is preferred that the bearing element is a disc.

It may be preferred that a reaction element is element is provided to abut against a reverse surface of the mounting seat of the bracket..

In such an embodiment, it may he prelerred that the reaction element is connected to a tie rod or bolt extending through the bracket and the bearing element and connected to the load member, such that tensile load force on the load member is transmitted to the bracket via the reaction element These and other aspects of the present invention will be apparent from and elucidated with reference to, the embodiment described herein.

An embodiment of the present invention will now he described, by way of examp'e only, and with reference to the accompany drawings, in which: Figure 1 is a Plan view of a first embodiment of a structural anchor arrangement in accordance with the invention; Figure 2 is a side view of the structural anchor arrangement of figure 1; Figure 3 is a perspective view from above of the structural anchor arrangement of figures 1 and 2; Figure 4 is a perspective view of the bracket of the embodiment of the prccecding figures; Figure 5 is a side view, similar to figure 3 but with the D ring, nut and bush removed from the view; Figure 6 is a plan view of the arrangement of figure 5; Figures 7A and 7B are plan and side views respectivdy ol the bush component of the structural anchor arrangement shown in the preceding figures.

Figures 8A and 8B are side and plan vies respectively of the D ring load member component of the structural anchor arrangement shown in the preceding figures.

Figure 9 is a plan view of an alternative embodiment ol structural anchor arrangement iii accordance with the invention; Figure 10 is a side view ol the structural anchor arrangement of figure 9.

Referring to the drawings, there is shown a structural anchor arrangement 1, particularly suitable for use in anchoring a suspended system such as an abseil cradle or the like anchored to the roof of a building. The structural anchor arrangement I is particularly suited also to anchoring to a membrane skin roof Problems exist in providing secure anchors on membrane skin roofs as a result of the inherent fragile nature of such roofs.

The present invention utilises an ingenious design of anchor including elongate bolts (toggk bolts 13 -see figure 10) that are able to secure into the sted sub frame structure below (lie membrane skin Too!.

The mounting bracket 2 is press formed from 3mm stainless steel plate so as to form a peripheral flange 3 surrounding a central raised section 5 of the bracket. The raised section of the bracket has inclined sloping surfaces rising up from the peripheral flange 3 to a substantially flat circular plateau forming a mounting seat 6 of the bracket. The mounting seat 6 of the bracket is provided with a central securing aperture 7 the purpose of which will he described ater. The peripheral flange 3 of the mounting bracket is providcd with an array of countersunk bolt holes 4 for receiving the toggle bolts 13. The embodiment of figures 1 to 8 is provided with four countersunk bolt holes 4. The embodiments of figures 9 and 10 is provided with eight countersunk bolt holes 4 in the peripheral flange 3 of the mounting bracket 2.

A circular bearing disk 8 is seated on the mounting seat 6 of the bracket and provided with a securing aperture 9 that is coaxial with the securing aperture 7 in the mounting seat 6 of the bracket. The hearing disk 8 is formed of 6mm stainless steel. On the underside of the mounting seat 6 of the bracket in the recess provided by the raised section 5 of the bracket, there is provided a reaction element in the form of a load spreader disc 12, which is substantially coextensive with the circular mounting seat 6 of the bracket and bearing disk 8.

The load spreader disc 12 is mounted at the end of a tie bolt 11 which extends through the securing aperture 7 and securing aperture 9 and terminates in a threaded bolt end 16 to which is mounted a securing nut 14. Mso mounted on the tie bolt 11 are a hush 15 and the load member D' ring 10. The bush 15 has a top 17 against which the securing nut 14 abuts and a projecting lip 18 which prevents the load member D' ring 10 from being removed from the tie bolt 11. The bush 15 has an outer cylindrical surface outer surface 20 of bush 15 about which central circular aperture 22 in the load member D' ring 10 is fitted such that the load member D' ring 10 is rotatably mounted so as to rotate about the bush 15. Thc bush 15 is providcd with a central bore 19 through which the tic bolt 11 extends.

By tightening the securing nut 14 down on the bush 15, the distal end 21 of the bush 15 is clamped against the upper surface of the stainless steel bearing disk 8. This secures the bearing disc S to the mounting seat 6 of the bracket, preventing the hearing disc S from rotating with the load member D' ring 10.

Also, in tightening the securing nut 14 down on the bush 15, the tie bolt 11 is pulled upwardly in so doing pulling the load spreader disk 12 firmly against the underside of the mounting seat 6 of the bracket. The mounting seat 6 of the bracket effectively becomes sandwiched between the bearing disk 8 and the 12. This ensures that the load applied to the load member ft ring 10 is spread over the entire area of the mounting seat 6 of the bracket and then abound the entire peripheral flange 3 of the mounting bracket 2 before being transmitted via the toggle bolts 13 to thc sub frame structure. Spreading the load in this way minimises any damage to the roof structure when heavy loads are applied via the load member ft ring 10 for example when suspending an ahseil cradle.

The use of the structural anchor a described (particularly with the bearing disc 8, rotatable mounting and the spreader disc 12 provided on the underside of the bracket in the cavity) in combination with the toggle tie bolts securing directly into the frame below a membrane roof structure provides a convenient and ingenious solution to the problems encountered in

prior art systems.

It should he noted that the above-mentioned embodiments illustrate rather than hmit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended daims. In the claims, any reference signs placed in parentheses shall not he construed as limiting the claims. The word "comprising" and "comprises', and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. In the present. specification, "comprises" means "includes or consists of' and "comprising" means "including or consisting of'. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. The mere fact that ccrtain measures arc recited in mutually diffcrcnt dcpcndcnt claims docs not indicate that a combination of these measures cannot be used to advantage.

Claims (14)

1. CLAIMS: 1. An anchor arrangement for mounting to a membrane skin of a structure, the anchor arrangement comprising: an anchor mounting bracket including a mounting flange provided with one or more fixing apertures and a raised section projecting from the flange. the raised section including a mounting seat for a hearing element; a bearing element seated on the mounting seat of the mounting bracket, the bearing element including a hearing surface provided on an opposed side to the mounting seat of the mounting bracket; a load member for attachment to a line; the load member hearing against the bearing surface of the bearing element and being rotatably mounted.
2. 2. An anchor arrangement according to claim 1, wherein the mounting seat includes a securing formation and the hearing element includes a securing formation aligned with the mounting seat securing formation.
3. 3. An anchor arrangement according to claim 2, wherein the securing formations comprise apertures arranged to receive a securing bolt or shaft to extend through.
4. 4. An anchor arrangement. according to any preceding claim, wherein the arrangement includes a bush element around which the load member is arranged to rotate.
5. 5. An anchor arrangement according to claim, wherein the bush element is arranged to clamp against the bearing element.
6. 6. An anchor arrangement according to any preceding claim, wherein ihe hearing arrangement is held against rotation.
7. 7. An anchor arrangement according to any preceding claim, wherein ihe hearing element is of greater material thickness than the material thickness of the mounting seat of the mounting bracket.
8. 8. An anchor arrangement according to any preceding claim, wherein the mounting seat is suhstantiaily planar.
9. 9. An anchor according to any preceding claim, wherein the bearing element is a disc.
10. 10. An anchor arrangement according to any preceding claim, wherein a reaction element is element is provided to abut against a reverse surface of the mounting seat of the bracket.
11. II. An anchor element according to claim 10, wherein the reaction element is connected to a tie rod or bolt extending through the bracket and the bearing element and connected to the load member, such that tensile load force on the load member is transmitted to the bracket via the reaction element.
12. 12. An anchor arrangemcnt according to any preceding claim wherein the load member comprises an eye or ring for attachment to a line.
13. 13. An anchor arrangcmcnt according to any prcccding claim uscd as a suspension anchor for an abseil cradle.
14. 14. An abseil system including an anchor arrangement according to any preceding claim.