WO2013124288A2

WO2013124288A2 - Safety anchor

Info

Publication number: WO2013124288A2
Application number: PCT/EP2013/053322
Authority: WO
Inventors: Robert Hirst
Original assignee: Capital Safety Group (Northern Europe) Limited
Priority date: 2012-02-24
Filing date: 2013-02-20
Publication date: 2013-08-29
Also published as: WO2013124288A3; GB201203193D0

Abstract

A safety anchor includes first and second spaced support components (3, 5) and an energy absorbing wire (17). The first and second spaced support components (3, 5) are each secured to a support plate (1 ) extending between the support components in such a way that the support plate and at least one of the support components are separable in the event of a load in excess of a predetermined threshold being applied to the safety anchor. The energy absorbing wire (17) extends between the first and second support components, the extent of the wire being greater than the spacing between the support components. The wire (17) is adapted to deform and absorb the energy of a fall when the support plate and at least one of the support components have been separated.

Description

SAFETY ANCHOR

This invention relates to a safety anchor which may be deployed on a rooftop or elsewhere, such as an accessible structure of considerable height, so as to provide protection for a user against a fall from height.

Single safety anchors are well known for protecting users from falls from height. Once connected to the safety anchor, the user is safe to work around a rooftop or like structure to a distance as far as an attachment lanyard allows. In the event of a fall, the roof anchor deploys to absorb the fall energy of the user. As an alternative to a single safety anchor, the safety anchor may be incorporated in a system of safety anchors interconnected by a guide cable or guide wire, for example as an intermediate safety anchor.

There are problems with existing safety anchors; for example the integrity of the safety anchor generally requires to be tested each year. Existing safety anchors are not always resistant to the forces applied during inspection and testing and can become damaged and require replacement.

It is therefore an object of the present invention to provide a safety anchor which overcomes, or at least ameliorates, the above-described problems.

According to the present invention there is provided a safety anchor comprising: first and second spaced support components, each secured to a support plate extending between the support components in such a way that the support plate and at least one of the support components are separable in the event of a load in excess of a predetermined threshold being applied to the safety anchor; and an energy absorbing wire extending between the first and second support components, the extent of the wire being greater than the spacing between the support components, the wire being adapted to deform and absorb the energy of a fall when the support plate and at least one of the support components have been separated.

The support plate may partially envelope the first and second support components. For example, the support plate may be part cylindrical and the first and second support components may be positioned within the part cylindrical support plate. The support plate may have a cross-section in the form of part, for example four sides, of a hexagon.

The first and second support components may be keyed to the support plate. For example, the first and second support components may be hexagonal in cross-section. In this way, the first and second support components may be received within the part hexagonal support plate. The first and second support components may each be secured to the support plate by fastening means extending between each of the support components and the support plate. For example, a threaded fastener may pass through the support plate and engage with the respective support component. More especially, diametrically opposed fasteners may be provided for each of the support components. The fasteners may secure the first and second support components against axial movement relative to the support plate.

One of the support components may be provided with means for securing the safety anchor to an anchoring plate. That one support component may be provided with a radially extending portion abutting an end of the support plate.

A part of the energy absorbing wire may protrude through an axially extending slot provided in the support plate.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawing which is a perspective view of one embodiment of a safety anchor according to the present invention.

The safety anchor comprises a part-cylindrical support plate 1 within one end of which is secured a first support component 3 and within the other end of which is secured a second support component 5. In use, the first support component 3 forms a lower support component and the second support component 5 forms an upper support component.

The support plate 1 has an axially extending slot 7 extending the entire length of the support plate, the purpose of which will be explained in more detail hereinafter.

The support plate 1 is keyed to the first and

second support components

3 and 5 to inhibit relative rotation between the support components and the support plate 1. In the illustrated embodiment, the support plate extends six sides of a hexagon, with the slot extending the other side sides, while the first and

second support components

3 and 5 are hexagonal in cross-section to key with the internal surface of the support plate 1.

The support plate 1 and the first and

second support components

3, 5 are secured against relative axial movement by means of threaded fastenings 9, such as grub screws, which in the illustrated embodiment engage in threaded openings formed in diametrically opposed regions of the support plate and are tightened to engage with the respective support component. In this way, the safety anchor can withstand an axial tensile load of 5kN without deformation or damage.

The first support component 3 is provided with a radially extending portion 11, such as a washer or a flange, which abuts against the (lower) end of the support plate 1 and with an internally threaded axial protrusion 13 which extends axially away from the support plate 1. The protrusion 13, in use, engages with an anchoring plate (not shown), which anchoring plate is secured for example to a roof or the like of a structure, such as a building. The protrusion 13 may be externally threaded so as to be able to be mounted in place on the anchoring plate without requiring access to the other (under) side of the anchoring plate.

The second support component 5 is provided with an axially extending protrusion 15 which extends axially away from the support plate 1. In use, the protrusion 15 is threaded, for example internally, to receive other components of a safety anchor system, for example to allow a user to attach to the safety anchor by way of a lanyard or to allow the safety anchor to be attached to other components of a safety anchor system.

An energy absorbing wire 17 extends between the first and

second support components

3, 5. As can be seen from the figure, the wire 17 is longer than the axial distance between the support components and is therefore deformed. In the illustrated embodiment, the wire 17 is formed with a curved portion 19, the curved portion extending through the axially extending slot 7 of the support plate 1.

In the event of a fall causing a load in excess of a predetermined threshold, for example in excess of 3kN, to be applied to the safety anchor, causes the support plate 1 to break away from at least one, and preferably both, of the support components and allows the energy absorbing wire 17 to take the force. The wire 17 orientates in the direction of pull and deforms (straightens) to absorb the energy of the fall.

Claims

A safety anchor comprising: first and second spaced support components (3, 5), each secured to a support plate (1) extending between the support components in such a way that the support plate and at least one of the support components are separable in the event of a load in excess of a predetermined threshold being applied to the safety anchor; and an energy absorbing wire (17) extending between the first and second support components, the extent of the wire being greater than the spacing between the support components, the wire being adapted to deform and absorb the energy of a fall when the support plate and at least one of the support components have been separated.
A safety anchor as claimed in claim 1, wherein the support plate (1) partially envelopes the first and second support components (3, 5).
A safety anchor as claimed in claim 2, wherein the support plate (1) is part cylindrical and the first and second support components (3, 5) are positioned within the part cylindrical support plate.
A safety anchor as claimed in claim 3, wherein the support plate (1) has a cross-section in the form of part of a hexagon.
A safety anchor as claimed in claim 4, wherein the support plate (1) has a cross-section in the form of four sides of a hexagon.
A safety anchor as claimed in any preceding claim, wherein the first and second support components (3, 5) are keyed to the support plate (1).
A safety anchor as claimed in claim 6, wherein the first and second support components (3, 5) are hexagonal in cross-section.
A safety anchor as claimed in any preceding claim, wherein the first and second support components (3, 5) are each secured to the support plate (1) by fastening means (9) extending between each of the support components and the support plate.
A safety anchor as claimed in claim 8, wherein a threaded fastener (9) passes through the support plate (1) and engages with the respective support component (3, 5).
A safety anchor as claimed in claim 8 or 9, wherein diametrically opposed fasteners (9) are provided for each of the support components (3, 5).
A safety anchor as claimed in claim 8, 9 or 10, wherein the fasteners (9) secure the first and second support components (3, 5) against axial movement relative to the support plate (1).
A safety anchor as claimed in any preceding claim, wherein one of the support components (3) is provided with means (13) for securing the safety anchor to an anchoring plate.
A safety anchor as claimed in claim 12, wherein the one support component (3) is provided with a radially extending portion (11) abutting an end of the support plate (1).
A safety anchor as claimed in any preceding claim, wherein part of the energy absorbing wire (17) protrudes through an axially extending slot (7) provided in the support plate (1).