WO2010049668A1

WO2010049668A1 - Safety anchor

Info

Publication number: WO2010049668A1
Application number: PCT/GB2009/002487
Authority: WO
Inventors: Karl Jones; Daniel Padfield
Original assignee: Latchways Plc
Priority date: 2008-10-28
Filing date: 2009-10-20
Publication date: 2010-05-06
Also published as: GB0819776D0; GB2464928A

Abstract

A safety device for use in a height safety or fall arrest system, has a mounting for mounting the device to a structure, and a securing body for securing a flexible line. The securing body includes a loop pass aperture through which a loop of the flexible line is arranged to pass and a loop securing projection about which the looped line is arranged to be hooked. The device may be mounted on top of one or more anchor structures such as anchor posts.

Description

SAFETY ANCHOR

This invention relates to a safety device, particularly for use with height safety or fall arrest systems.

Height safety equipment is used to prevent personnel working at height from falling to the ground below. A typical arrangement is where personnel wear harnesses attached to one end of a lanyard and the other end of the lanyard is attached to a cable such that it is free to move along the length of the cable. The cable is fixed between anchors that are attached to a structure and personnel can then move freely along the length of the cable in order to access work areas that need attention such as maintenance. More sophisticated cable systems are intended for long lengths of cable where access is required over a large area often requiring deviations in the line of the cable. These systems tend to use intermediate anchor points through which the cable passes in order to limit cable spans between anchors and to allow deviations such as corners and angle changes, often to follow deviations in a structure surface. Sophisticated traveler devices have been developed to travel along the cable and pass over intermediate anchors, without any need to be detached from the cable. A person can then attach their lanyard to such a traveler device and move along the length of the cable across intermediate anchors.

Some cable systems are positioned to stop personnel from gaining access to the edge of a building and therefore avoid the possibility of falling. The problem with such cable systems is that many maintenance tasks such as gutter clearing require access at the edge of buildings and so they are too restrictive. The more usual cable systems allow personnel access to the edge of building but arrest a fall safely in the unfortunate event that someone should accidentally fall. These systems are known as fall arrest systems. The loading on end and corner anchors on such systems can be high depending on the distance through which someone falls and whether there are falls by multiple personnel.

Cable system anchors, particularly those fitted to roofs, typically perform two basic functions. The first is to hold the cable clear of the roof surface in normal access use by personnel so that the cable, particularly in mid span where it tends to sag, cannot scratch the roof protective coating. Also, the travelers that are attached to the cable and to personnel and which are free to move along the cable length to allow access along the cable system must be prevented from hitting the roof surface. The second basic function is to withstand loading transmitted through the cable in a fall without over loading the anchor fixings to the roof surface, particularly with respect to tensile loading on the fixings and also damaging the roof to which the system is attached. Such over loading of the fixings, and/or damage to the roof would compromise the safety of the cable to which a faller or a number of fallers is attached before and after a fall event.

Particularly when accessing the corners of building roofs there are often situations in which the safety line is payed out to a large extent and, should a fall occur, the pendulum swing and length of drop of a person over the edge of a building would be unacceptably large. A solution to this problem is to temporarily attach the line to an anchor post or the like, but this has risks especially if the operative is required to detach the safety line in order to pass it through the securing eye of such a temporary securing post.

One known anchor that can be attached directly and safely to the surface of a roof is disclosed in WO2005/079922. In the arrangement described an anchor post is provided with an integral energy absorbing arrangement that is deployed in the event of a fall. It is intended that the present invention is of particular utility when used in combination with such an energy absorbing anchor.

According to a first aspect, the present invention provides a safety device for use in a height safety or fall arrest system, the device comprising:

mounting means for mounting the device to a structure;

a securing body for securing a flexible line , the securing body including;

a loop pass aperture through which a loop of the flexible line is arranged to pass; and, a loop securing projection about which the looped line is arranged to be hooked.

It is preferred that the mounting means is arranged to enable the device to be mounted so as to be rotatable about a rotational axis. This provides a greater degree of maneuverability and flexibility in use for an operative.

In one embodiment the mounting means may comprise a mounting aperture in the body for an anchor bolt.

Beneficially, the loop pass aperture is provided on an opposed side of the body from the loop securing projection. Preferably, the mounting means is provided intermediate between the loop pass aperture and the loop securing formation.

In a preferred embodiment, the loop securing formation comprises a projecting element extending in a first direction away from the mounting means.

Beneficially, the projecting element includes a relatively narrow waist portion part way along its length. The waist portion aids in positive and secure location of the line loop when it is hooked about the loop securing projection.

Desirably, the loop pass aperture is provided in a body portion extending away from the mounting means in an opposed direction to the projecting loop securing element.

The loop pass aperture is preferably provided in a portion of the body which is inclined to extend upwardly and outwardly in a direction away from the mounting means. The loop pass aperture beneficially has a continuous perimeter extending about the aperture.

It is preferred that the device includes a capture arrangement arranged to capture the line when looped around the loop securing projection. The capture arrangement preferably includes a capture recess into which the line is pulled. -A-

The capture arrangement is beneficially resiliency deflectable/flexible from a normal position to an access position in which the line can pass into and out of the capture arrangement. In a preferred embodiment, the capture arrangement comprises resiliently deflectable clip that is mounted adjacent the loop securing projection. The clip may be secured with respect to the body of the device by means of a mounting anchor such as a mounting bolt which also secures the device to a supporting structure.

According to a further aspect, the invention provides a height safety or fall arrest system comprising one or more anchor structures provided with a safely device as defined herein.

According to a further aspect, the invention provides an anchor structure for use in a height safety or fall arrest system, the anchor structure having mounted at its upper end a safety device as defined herein.

Beneficially, the anchor structure comprises an upstanding post. The anchor structure preferably includes an energy absorber arrangement arranged to be deployed when the post is deformed under the force applied during a fall event.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a side view of a safety device in accordance with the invention;

Figures 2 4 6 8 and 10 are perspective views in sequence of a loop of flexible line being secured with respect to the device;

Figures 3 7 9 and 11 are plan views in sequence of the device (corresponding to the views of figures 2 4 6 8 and lO).

Referring to the drawings, there is shown a safety line capture device 1 which is fixed to the domed top 2a of an anchor post 2 which is mounted on top of a structure such as a building roof. The safety line capture device 1 comprises a body 3 through which extends a mounting bolt 4 which secured to the top of the mounting post 2 enabling rotation of the safety anchor device 1 about the axis of bolt 4 when mounted to the top of the post 2.

The body 3 of the anchor device 1 is provided with a perimeter 5 defining a rope passage aperture 6 to one side of the mounting bolt 4. To the other side of mounting bolt 4 is provided a securing projection 7 extending away from the mounting connection at bolt 4 to the post 2. The securing projection? includes a waist portion 8 part way along the length of the projection, and which is narrower then the distal end of the projection 7. Connected to the body 3, on its underside is a resiliently flexible plastics clip 9. The plastic clip 9 is secured to the body 3 of the safety anchor device 1 by means of a nut (not shown) secured on the threaded shaft of the mounting bolt 4. The clip 9 is provided with a triangular boss 10 which is received in a complimentary triangular aperture 11 provided in the body 3 of the safety line capture device 1. The boss 10 and aperture 11 provide positive location for engagement for securing of the clip 9 with the body 3 of the safety line capture device 1.

The resilient clip 9 cooperates with the underside of the securing projection 7 such that, in a normal at rest position, an abutment portion 12 of the clip 9either engages with the underside of the thumb extension 7 or lies closely adjacent thereto.

An angled lead-in ramp 13 of the clip 9 extends downwardly away from the abutment portion 12 and also away from the securing projection 7. Intermediately between the triangular boss 10 and the abutment portion 12, the clip 9 is provided with a shaped recess 14. The purpose of the lead in 13 as will be described in detail later is to permit a length of securing rope to be pulled from externally of the device into the recess 14 of the clip 9 so as to be captured between the clip and the securing projection 7 of the device 1.

The part of the body 3 including the perimeter 5 defining the aperture 6 is inclined angularly upwardly as it extends in a direction away from the bolt 4. this encourades the loop of the line to be passed through the aperture 6 from the underside of the device as is required for correct operation. In use and as sequentially shown in both in perspective view and in plan view in figures 2 to 11 there is shown the method by which the safety line capture device is used to capture a length of safety line 15. It is important to note that the device enables the rope to be secured to the post 2 without the need for an operative to un-secure an already attached safety line (thereby to expose a free end of the safety line). The system can be used with a safety line already secured to an operative.

A length of safety line 15 has a portion which is initially formed in to a loop 15a by an operative and inserted sideways through aperture 6 from the underside of the perimeter 5. The upwardly extending length of the perimeter 5 in a direction away from the mounting bolt 4 aids in inserting the length of safety Iinel5 from the underside of the aperture 6.

As shown in figures 4 and 5, following the insertion of the loop portion 15a through the aperture 6, the loop portion 15a is pulled passed the bolt 4 and as shown in figures 6 and 7 the loop 15a is pulled to hook or loop over the top of the securing projection 7. Following this, and as shown most clearly in figures 8 and 9, the loop 5a is pulled back slightly to engage in a pinch formation between the securing projection 7 and the lead-in ramp 13 of the flexible clip 9. From this position and as shown most clearly in figures 8 and 9, the loop 15a is next pulled smartly back in the direction of arrow A causing the lead-in ramp 13 of the clip 9 to initially resiliency deflect away from the securing projection 7 and subsequently flex back to return to its normal position with the abutment portion 12 laying adjacent to, or contiguous with, the securing projection 7 and the loop 15a received snugly in the clip recess 14. This is the configuration shown in figures 10 and 11. The loop portion 15a is wrapped around the waist portion 8 of the projection 7.

In the event of a person falling, tension on the safety Iinel5 will be in the direction of arrows B (tangentially to the post 2). This will cause the loop 15a to tighten about the body 3 of the safety anchor device 1.

Assuming that no fall event occurs and the operative wishes to release the engagement with the safety device 1, the tension on the loop 15a is relaxed and the loop is urged in the opposed direction to arrow A whilst simultaneously flexing the lead in ramp 13 in a downward direction in order to open up the space between the abutment portion 12 and the securing projection 7. This permits the loop 15a to pass out from its captive arrangement secured in the clip recess 14. The safety line loop 15a can then be pulled back through the aperture 6.

In use an operative who requires to secure the safety line 15 to a temporary anchor point (in order to reduce the effective length of the rope i.e. the length of the rope between the operative and a secured anchor point) can simply, without the need to release connection of the safety make a loop and urge it through the aperture 6 in the relevant safety anchor device 1 mount to a securing post 2. With the temporary anchor arrangement safely established the operative can continue their business whilst effectively being temporarily secured to the anchor post 2.

The pivotal connection between the safety line capture device 1 and the support post 2 gives a greater degree of flexibility and mobility for the operative. In certain embodiments it is envisaged that the device could function adequately without the provision of the clip 9 in which case the loop 5a is simply retained by being looped over the securing projection 7 and then extending back through the aperture 6 in the body 3 of the device. It will however be appreciated that greater level of security and safety is provided by provision of the clip 9.

The anchor post is preferably of a type provided with an energy absorbing device to ensure absorption of fall energy during a fall event. Such an arrangement is described in for example WO2005/079922.

Claims

Claims:

1. A safety device for use in a height safety or fall arrest system, the device comprising:

mounting means for mounting the device to a structure;

a securing body for securing a flexible line , the securing body including;

a loop pass aperture through which a loop of the flexible line is arranged to pass; and,

a loop securing projection about which the looped line is arranged to be hooked.

2. A safety device according to claim 1, wherein the mounting means is arranged to enable the device to be mounted so as to be movable (rotatable or pivotable) about an axis.

3. A safety device according to claim 1 or claim 2, wherein the mounting means comprises a mounting aperture in the body for an anchor bolt.

4. A safety device according to any preceding claim, wherein the loop aperture is provided on an opposed side of the body from the loop securing formation.

5. A safety device according to any preceding claim wherein the mounting means is provided intermediate between the loop aperture and the loop securing formation.

6. A safety device according to a preceding claim, wherein the loop securing formation comprises a projecting element extending in a first direction away from the mounting means.

7. A safety device according to claim 6 wherein the projecting element includes a relatively narrow waist portion part way along its length.

8. A safety device according to claim 6 or claim 7, wherein the loop aperture is provided in a body portion extending away from the mounting means in an opposed direction to the projecting loop securing element.

9. A safety device according to any preceding claim, wherein the loop aperture is provided in a portion of the body which is inclined to extend upwardly and outwardly in a direction away from the mounting means.

10. A safety device according to any preceding claim, wherein the device includes a capture arrangement arranged to capture the line when looped around the loop securing projection.

11. A safety device according to claim 10, wherein the capture arrangement includes a capture recess into which the line is pulled.

12. A safety device according to claim 11, wherein the capture arrangement is resiliently flexible from a normal position to an access position in which the line can pass into and out of the capture arrangement.

13. A safety device according to any of claims 10 to 12, wherein the capture arrangement comprises resiliently deflectable clip that is mounted adjacent the loop securing projection.

14. A safety device according to claim 13, wherein the clip is secured withy respect to the body of the device by means of the mounting anchor.

15. A height safety or fall arrest system comprising one or more anchor structures provided with a safety device according to any preceding claim.

16. An anchor structure for use in a height safety or fall arrest system, the anchor structure having mounted at its upper end a safety device according to any preceding claim.

17. A system or structure according to claim 15 or 16, wherein the anchor structure comprises an upstanding post.

18. A system or structure according to claim 17 wherein the post includes an energy absorber arrangement arranged to be deployed when the post is deformed under the force applied during a fall event.