Fall arrest or height safety systems commonly comprise a safety line comprising a wire rope or cable extending adjacent to a region in which personnel to be protected will work or travel. In use the personnel wear safety harnesses connected through a lanyard to a traveller able to move along the safety line so that as a user moves about the region the traveller is automatically dragged along the safety line to follow them by the safety lanyard.

Where the fall arrest system is arranged so that the safety line is substantially horizontal, movement of the traveller along the safety line is substantially completely due to the traveller being dragged along by the safety lanyard. In systems where the safety line is vertical or at an angle significantly inclined to the horizontal, the movement of the traveller will be controlled by a combination of being dragged by the safety lanyard and forces acting on the traveller due to gravity. However, the movement of the traveller along the safety line will still be ultimately controlled by forces transmitted along the safety lanyard so that the traveller moves. along the safety line and follows the user.

Generally, a complete height safety system will comprise one or more safety lines each extending between two end anchors.

Between these end anchors the safety line may be supported, guided and located by a number of intermediate supports in order to avoid excessively long unsupported lengths of safety line and to allow the safety line to include ends or curves so that personnel throughout a region having any desired shape or extent can be protected.

The intermediate supports used to support the safety line generally comprise a substantially cylindrical sleeve through which the safety line passes connected by a bracket to a fixed supporting structure. The support and traveller are designed and arranged to cooperate so that the traveller can automatically traverse the intermediate supports as it moves along the safety line as urged by the safety lanyard to follow the user.

The safety line intermediate support must be able to withstand relatively high loads when a fall rest event takes place and must be able to remain in place for long periods with little or no maintenance. In order to provide the required strength and avoid excessive maintenance demands the part of the support bracket surrounding the safety line will have a significant thickness of material in order to provide the necessary physical strength and resistance to accidental or environmental damage. However, the thickness of the material of the intermediate support bracket surrounding the safety line can cause the traveller to become caught on the bracket by the traveller failing to ride over the discontinuity in thickness where the traveller moving along the safety line encounters the intermediate support bracket part surrounding the safety line.

A similar problem can also arise with the mechanism allowing the traveller to pass over the intermediate support bracket.

There are a number of known arrangement of cooperating travellers and support brackets which allow a traveller moving along a safety line to traverse a safety line support automatically with engagement of the traveller on the safety line being maintained continuously throughout, as is necessary in a fall safety system.

All of these arrangements require that the traveller and support be properly aligned in order to allow smooth uninterrupted traversing of the bracket by the traveller.

Failure to have the traveller and support bracket properly aligned can result in a traveller"locking up"by becoming jammed against the support.

It will be understood that anything causing the traveller to fail to smoothly traverse the intermediate support and requiring user action in order to free the traveller or restart its movement across the support bracket is highly undesirable in a fall safety system because reliable use of such systems is highly dependent upon their functioning automatically and without causing inconvenience to users. In practice, if a fall safety system is inconvenient in use many intended users will simply not use the fall safety system, resulting in unnecessary injuries and deaths.

In order to avoid these problems of the traveller failing to smoothly traverse the intermediate support because of the discontinuity between the support and safety line or misalignment of the traveller and support it is usual for intermediate support to have elongate sections extending along the safety line beyond the main structure of the support itself. These elongate portions, commonly referred to as bullets or noses, allow the alignment of the traveller relative to the support to be controlled and stabilised before the traveller contacts the support itself. Further, the noses or bullets are provided with tapered end sections in order to minimise the discontinuity between the safety line and the support. Both of these measures reduce the chance of the traveller becoming locked to the support or otherwise failing to smoothly traverse the intermediate support.

However, in practice considerable problems have been encountered with such extensions on support brackets. The extensions tend to fail and snap off the support brackets, and it is then necessary to replace the extensions in order to ensure the reliable operation of the height safety system.

The tendency of support bracket extensions to fail is a considerable problem in height safety systems.

This invention has made an attempt to overcome this problem, at least in part.

This invention provides a support suitable for use in a fall arrest system to support a safety line and comprising a body portion having a first opening arranged to receive and retain a safety line, attachment means suitable to attach the support to a fixed structure and an extension element extending from the body portion and having a second opening arranged to receive a safety line, the body portion and the extension element being arranged so that the first and second opening can receive the same safety line and being linked together by a resilient member.

The use of a resilient member connecting the main body portion of the support with the extension element greatly reduces the likelihood the extension element failing and snapping off from or otherwise becoming detached from the support. This reduction in the chance of failure of the extension is highly advantageous.

The use of a resilient member to link the extension element to the main body of the support also provides the further advantage of allowing the length and profile of the extension element to be optimised for the smooth traversing of the support by the traveller without having to compromise to avoid extension element lengths or shapes which were previously unacceptable because of the high probability of failure.

A preferred embodiment of the invention will now be described by way of example only with reference to the accompanying diagrammatic figures, in which; Figure 1 shows a side elevational view of a bracket according to the invention, Figure 2 shows a perspective view of the bracket of Figure 1, Figure 3A shows a partial cross sectional view of the bracket of Figure 1 when the safety line is straight, and Figure 3B shows the view of Figure 3A when the safety line is bent.

An intermediate support suitable for use in a system and employing the invention is shown in the Figures.

A continuous safety line 1 forming a part of a fall arrest system passes through and is supported by an intermediate support 2.

The support 2 comprises a substantially cylindrical body portion 3 having a central bore 13 through which the safety line 1 passes. The support 2 can be connected to a fixed structure through an arm 4 having a location element 5 so that the safety line 1 can be fixedly located relative to the fixed structure.

The illustrated support 2 has the body section 3 supported by an arm 4 which is substantially planar and is thinner than the diameter of the body 3 and the diameter of the safety line 1 for at least part of its length. This support 2 is able to cooperate with a traveller having an element substantially surrounding the safety line 1 and broken by a slot sufficiently wide to pass over the arm 4 so that the traveller can traverse the safety line, but narrower than the diameter of the safety line 1 so the traveller cannot become disengaged from the safety line 1. This allows the traveller to automatically traverse the support 2 as it moves along the safety line 1.

Other forms of mechanism allowing the traveller to traverse an intermediate support are known. Some of these alternative arrangements would require a different shape or form of arm 4 connecting the central body section 3 of the support 2 to the fixed structure. Further, some of these alternative arrangements might require special cross sectional shapes of the central body portion 3 or additional mechanical elements beyond those shown to guide, align and cooperate with the traveller.

In view of the very large number of such arrangements which have been developed or proposed it will not be attempted to describe them all or the application of the present invention to them in detail here.

However, the present invention can be used with any such arrangements if desired.

From each end of the body 3 of the support 2 an extension or nose section 6 extends along the safety line 1 away from the body 3. Each extension 6 comprises a substantially cylindrical body section 7 having the same external diameter as the body 3, a first tapered end section 8 tapering to a narrower diameter towards and along the safety line 1 away from the body 3 and a second substantially cylindrical end section 17 having a reduced diameter extending along the safety line 1 towards the body 3. Each of the extensions 6 is connected to the body 3 through a resilient section formed by a coil spring 9 coiled around the safety line 1. That is, the safety line 1 extends through the cylindrical aperture defined by each of the coil springs 9.

Thus, the extensions 6 are not connected directly to the body 3 of the support 2 but are each connected to the body 3 through a respective coil spring 9.

Each coil spring 9 is connected to a respective sleeve or tubular element 10 which has a first substantially cylindrical tubular section 14 shown in Figures 3A and 3B, which extends inside the body section 3 between the internal surface of the bore 13 through the body 3 and the surface of the safety line 1, a flange section 15 located between the end of the body 3 and the coil spring 9 and a second substantially cylindrical tubular section 16 which projects beyond the flange section 15 and extends inside the coil spring 9 between the internal surface of the coil spring 9 and the surface of the safety line 1. Each tubular element 10 is secured within the body 3 by a resiliently biased tooth 11 which projects into an aperture 12 through the body 3.

The aperture 12 is perpendicular to the bore through the body 3. Each tooth 11 is resiliently connected to the rest of the element 10 by a resilience which tends to urge the tooth 11 outwardly away from the centre of the bore in the figures so that the tooth 11 is resiliently biased to pass into and remain in the aperture 12. The resilience allows sufficient movement of the tooth 11 relative to the rest of the element 10 that the tooth 11 can be pushed inwards against the resilient biassing sufficiently to disengage the tooth 11 from the aperture 12.

The second cylindrical tubular section 16 of the sleeve 10 and the second end section 17 of the extension 6 both have a substantially cylindrical outer surface with a threaded external profile (not visible in the figures). The extension 6 is connected to the sleeve 10 and thus to the rest of the body 3 by the spring 9 passing over the external surfaces of the second tubular section 16 and second end section 17.

The coil spring 9, the second tubular section 16 and second end section 17 are arranged and sized to cooperate so that the spring 9 is expanded and deformed by the sections 16 and 17 to provide a secure link between the extension 6 and the sleeve 10. The use of threads formed on the external surfaces of the sections 16 and 17 prevent the sections 16 and 17 being pulled out of the coil spring 9 and allow the coil spring 9 to be detached from the sections 16 and 17 only by unwinding the coil spring 9 from the threaded surfaces.

As is well known, coil springs tend to tighten when unwound and this helps to ensure that the coil spring 9 remains in place.

The second tubular section 16 has an internal chamfered surface flared outwardly in a direction away from the body 3.

The angle of the chamfer is preferably 10°, although other angles can be used if desired.

Preferably, the chamfer of the element 10 begins at a position along the element 10 corresponding to the end of the body 3 or slightly inside the body 3 so that the chamfer section 16 extends within the second tubular section 16, flange section 15 and a part of the first tubular section 14.

In the illustrated embodiment the thickness and material of the first tubular section 14 is such that the tubular section 14 can resiliently deform to provide the necessary resilience to allow the tooth 11 to disengage from the aperture 12.

However, a separate resilient member could be provided if preferred.

This allows each tubular element 10 and attached coil spring 9 and extension 6 to be easily connected to and disconnected from the body 3 and the rest of the support 2. In order to attach an element 10 and the associated coil spring 9 and extension 6 to the body 3, the element 10 is inserted into the bore through the body 3 and then pushed inwards along the bore and twisted until the tooth 11 is aligned with the recess 12. The resilient bias will then urge the tooth 11 into the recess 12 so that the element 10 is attached to the body 3.

In order to release the element 10 and attached parts from the body 3 the tooth 11 is pushed inwardly towards the centre of the bore of the body 3 until the tooth 11 is disengaged from the aperture 12. The element 10 can then be pulled out of the body 3.

When the safety line 1 is in place passing through the bore in the body 3, the amount of inward movement available to a tooth 11 will be limited by the tooth 11 contacting the safety line 1.

Preferably, as a safety precaution to prevent inadvertent release of the elements 10, each tooth 11 should be sized so that this limit on inward movement makes it impossible for the tooth 11 to move inwardly sufficiently far to become disengaged from the aperture 12 when the safety line 1 is inside the bore through the body 3.

In the illustrated embodiment of the invention there are a paid of diametrically opposed apertures 12 and each element 10 has a pair of teeth 11 arranged to engage both apertures 12 simultaneously.

This arrangement prevents the elements 10 and attached coil springs 9 and extensions 6 from being inadvertently released from the body 3 and moving along the safety line 1 away from the rest of the intermediate support 2.

It is believed that this arrangement for retaining extensions using resiliently supported teeth is advantageous and inventive in its. own right.

This arrangement for retaining the extensions 6 on the body 3 is preferred, but other known methods for attaching extensions to safety line support brackets could also be employed.

The use of the elements 10 has the advantage that elements 10 formed of an insulating plastics material can be used to prevent electrical contact between the body 3, safety line 1 and coil springs 9. This allows dissimilar metals to be used for these parts without causing the corrosion problems which would normally arise where dissimilar metals are in contact.

Preferably, the safety line 1 and coil springs 9 are made of stainless steel while the body 3, arm 4 and location element 5 are formed of an aluminium alloy. The body 3, arm 4 and location element 5 are preferably formed as an integral unit in a single extension operation. Preferably, the extensions 6 are formed of a plastics material having a high level of wear resistance and a low coefficient of friction.

When a traveller moving along the safety line 1 approaches the intermediate support 2, the traveller first contacts a -7 tapered section 7 of an extension 6. The discontinuity in diameter between the end of the tapered section 8 and the safety line 1 is relatively small so that there is little chance of the traveller becoming stuck. As the traveller continues to move along the safety line 1 the traveller will pass over the tapered section 8 onto a substantially cylindrical section 7. As the traveller moves along the cylindrical section 7 the location and orientation of the traveller relative to the support 2 is controlled and adjusted so that when the traveller attempts to pass over the body 3 and to have the support arm 4 pass through the cooperating slot on the traveller the traveller is able to traverse the support 2 automatically, smoothly and without interruption.

It will be understood that the cylindrical element 7 can only orient and locate the linear position of the traveller relative to the axis of the safety line 1 and the extension 6 and that further means for controlling the angular orientation of the traveller about the axis of the safety line 1 and extension 6 will also be required so that the arm 4 and traveller slot are properly aligned. Many mechanisms for carrying out such angular alignment of a traveller around a safety line 1 are known or have been proposed and the described extension elements 6 with coil springs 9 or other resilient means can be used together with any of these mechanisms if desired.

A similar requirement to align the traveller relative to an about the safety line axis also applies to other known cooperating arrangements allowing a traveller to traverse a support and not just in the described arm and slot arrangement.

In general, the longer the extension 6 extends from the body 3 the more effectively the alignment of the traveller relative to the intermediate support 2 can be controlled and the lower the chance of the traveller failing to smoothly traverse the intermediate support 2. Similarly, the longer the tapered section 8 extends along the safety line 1 and the thinner the narrow end of the tapered section 8 the more smoothly the traveller will pass over the support 2.

However, in practice the shallowless of taper of the tapered section 8 and the thinness of its end cannot be increased indefinitely and must be limited to avoid the tapered section X becoming too fragile.

In previously known intermediate support designs problems with failure or breakage of the extensions have been encountered. The failed or broken extensions tend to move away from the rest of the intermediate support along the safety line resulting in the exposure of relatively large jagged discontinuities at the break. Travellers contacting the breaks naturally tend to jam. As a result, such broken extensions must be removed and replaced. This is generally a complex and demanding task requiring that the safety line be released from one of its end anchor points and removed from the broken intermediate support, and any intermediate supports between the end anchor point and broken support, so that the broken extension can be replaced. The safety line must then be rethreaded through the system and usually retensioned back to a desired pretension value.

Not only is the breakage of extensions a problem but it has been found that longer extensions are more prone to breakage.

Thus there is problem that the length of the extensions cannot be freely selected based on the requirements for the desired smooth reliable traversing of the support by the traveller, but, must often be limited in order to avoid excessive breakage rates.

It is believed that the tendency of extensions to break is caused by loads applied by the safety line 1 through the extensions to the intermediate support perpendicular to the safety line. These loads perpendicular or transverse to the safety line arise due to oscillation of the length of the line between supports, which can occur due to interaction between the traveller and safety line in use or can be driven by the wind. Further, such transverse loads will also be applied by the safety line when a fall arrest event occurs.

It has been found that these transverse or perpendicular loadings tend to cause breakage in extensions close to the point at which they are attached to the rest of the intermediate support structure. When using the present invention these transverse loads are reduced by bending of the coil spring 9 as shown in Figure 3B so that loading on the remainder of the extension 6 is insufficient to cause breakage either due to the large perpendicular loads encountered when a fall arrest event occurs or due to the smaller but longer duration load which occurs due to movement or oscillation of the safety line such as encountered in use or due to wind.

The transverse loads which would otherwise be applied by movement of the safety line 1 are further reduced by the internal chamfer of the end of the element 10. As can be seen best from Figure 3B the chamfer or flare at the end of the element 10 allows sideways movement of the safety line 1 to take place without any transverse load being applied to the element 10 by the safety line 1 beyond the end of the body 3 until the bending of the safety line 1 is equal to the chamfer angle.

In most fall arrest systems the safety line 1 will be under a significant pretension so that bending or displacement of the safety line 1 to an angle of 10° or more so that the safety line 1 contacts the chamfered surface of the element 10 will be unusual. Further, even where the bending of the safety line 1 is so great that it contacts the chamfered surface the amount of the transverse loading applied through the element 10 will still be less than would be the case if the chamfer was not present.

Accordingly, use of an element 10 having a chamfered end in combination with the use of a spring to connect the extension 6 to the element 10 as shown in the illustrated embodiment is preferred. However, use of a chamfer is not essential.

In Figures 3A and 3B only a part of the body 3 and one element 10 is shown. It will be understood by comparison with Figures 1 and 2 that a part of a corresponding second element 10 should also be visible in Figures 3A and 3B, but this has been omitted for clarity.

In the described embodiment a stainless steel coil spring is used. Use of such a coil spring, particularly a stainless steel coil spring, is preferred. However, other forms of resilient element could be used such as an elastomeric sleeve or other arrangement of elastomeric or other resilient members.

The invention has been described herein with reference to the specific embodiment shown in the figures. However, it will be understood by the skilled reader that this is merely an illustrative example and that variations are possible within the scope of the claims which follow.