GB2307266A

GB2307266A - Fall arrest system

Info

Publication number: GB2307266A
Application number: GB9523512A
Authority: GB
Inventors: Michael John Luke
Original assignee: COUNTY SAFETY SERV Ltd
Current assignee: COUNTY SAFETY SERV Ltd
Priority date: 1995-11-17
Filing date: 1995-11-17
Publication date: 1997-05-21
Also published as: GB9523512D0

Abstract

A fall arrest system that reduces the risk of a fallen worker injuring himself by swinging into an object comprises an arcuate beam (9) and an elongate beam (13). The arcuate beam (9) and elongate beam (13) are movable relative to beams (7) so that they may be positioned above the object under maintenance. The free end of a pivotable beam (15) is movably supported by the arcuate beam (9) and can be locked in a position relative to the arcuate beam (9). Fall arrest devices (not shown) are movable in the longitudinal direction of the pivotable beams (15) and along the length of the elongate beam (13).

Description

FALL ARREST SYSTEM The present invention is concerned with a fall arrest system, for example for use by aircraft maintenance personnel when working on aircraft in hangars or the like.

It is well known to provide fall arrest systems for use by aircraft maintenance personnel working on many types of civil and military aircraft. Such fall arrest systems are intended to prevent injury to maintenance personnel should they fall from the aircraft being maintained. A disadvantage of known fall arrest systems is the difficulty of positioning the system in a manner which, although it may prevent a worker from injuring himself by falling to the ground, also prevents a fallen worker injuring himself by swinging into an aircraft or damaging an aircraft by swinging into it.

It is therefore an object of the present invention to provide a fall arrest system which can be positioned in a manner which eliminates, or at least reduces, the risk of a fallen worker injuring himself by swinging into an aircraft or other structure.

According to the present invention there is provided a fall arrest system comprising an arcuate beam adapted to be positioned above an object, a pivotable beam mounted such that the free end thereof is supported relative to the arcuate beam, and a fall arrest device movable in the longitudinal direction of the pivotable beam.

The arcuate beam may be mounted in a framework. The pivotable beam may be mounted in a pivotable manner in the framework.

The pivotable beam may be secured in position relative to the arcuate beam.

The arcuate beam may be movable relative to the object. In this case, it should be possible to lock the arcuate beam in position relative to the object. The arcuate beam may be movable in two directions arranged substantially at right angles.

The fall arrest system may include a rectilinear beam provided with a further fall arrest device movable in the longitudinal direction thereof. Two rectilinear beams may be provided arranged parallel to and spaced apart from each other. A pivotable beam may be mounted to each side of the rectilinear beam, or to each side of the parallel arrangement of two rectilinear beams. Thus the axis of pivoting of the pivotable beams will correspond substantially with the longitudinal axis of the rectilinear beam(s).

The arcuate beam may extend over substantially 180 degrees.

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 drawings in which: Figure 1 is a diagrammatic plan view of an aircraft hangar provided with one embodiment of a fall arrest system according to the present invention; Figure 2 is a diagrammatic plan view, on a larger scale to Figure 1, of part of the fall arrest system illustrated in Figure 1; Figure 3 is a diagrammatic illustration of one end of a pivotal beam for use in the fall arrest system shown in Figures 1 and 2; Figure 4 is a diagrammatic illustration of locking means for securing the pivotal beam of the fall arrest system shown in Figures 1 to 3; Figure 5 is a diagrammatic plan view illustrating another embodiment of a fall arrest system according to the present invention;; Figure 6 is a diagrammatic plan view, to a larger scale than Figure 5, of part of the fall arrest system shown in Figure 5; and Figure 7 is a diagrammatic cross-sectional view of an alternative form of beam for use with the fall arrest system according to the present invention.

Figure 1 shows an aircraft hangar 1 in which there are positioned two aircraft 3, 5. Although the aircraft illustrated are military aircraft, the fall arrest system according to the present invention is applicable to civil aircraft and to other applications where there is a risk of a worker falling from a structure and injuring himself.

Two independent fall arrest systems are illustrated in Figure 1, but clearly a greater or a lesser number of systems can be employed depending on the number and size of the structures to be worked upon and the space available.

As shown in Figures 1 and 2, each fall arrest system is supported on a pair of spaced parallel horizontal beams 7 to permit the system to be moved laterally across the hangar to any desired position.

The fall arrest system includes an arcuate beam, for example a semi-circular beam 9, mounted so as to be movable relative to the beams 7 and supported by a pair of beams 11 arranged transverse to the beams 7 and movable with the beam 9. Clearly, the beam 9 need not be semi-circular and could take any desired arcuate form extending over an arc greater or lesser than 180 degrees. The beam 9 is generally C-shaped in cross section for reasons that will be explained in more detail hereinafter. Beam 9 is movable relative to the beams 7 in such a manner that it can be locked in a desired position relative to the beams 7.

Also extending transverse to the beams 7 and movable with the semi-circular beam 9 is an elongate beam 13 which, in the illustrated embodiment extends beyond each of the beams 7 to permit maintenance work to be safely carried out on the fuselage and tailplane of an aeroplane. As illustrated, the beam 13 passes through the centre of curvature of the semi-circular beam 9 and bisects the beam 9 into two equi-angular portions. Beam 13 is generally Ishaped in cross-section to support at least one fall arrest device (not shown) of conventional design in a manner such that the fall arrest device can be moved along the length of the beam. A fall arrest device as described herein is intended to include what are known as descent control units in addition to conventional fall arrest devices.

Pivotally mounted on the beam 13 adjacent to one of the beams 7 are two beams 15. The pivotably mounted end of the beam 15 is shown in more detail in Figure 3, the beam 15 being pivotably mounted on the beam 13 by way of a high tensile bolt (not shown) or the like passing through apertures provided in the beam 13 and through a tube mounted at the end of the beam 15. The free ends of the beams 15 are received and supported in the C-shaped section of the semi-circular beam 9 and are each movable, for example by way of rollers (not shown), such as nylon rollers, mounted between the free end of the beam 15 and the semi-circular beam 9, over an arc of substantially 90 degrees as shown by the dashed lines in Figures 1 and 2.

The beams 15 are movable in a manner which permits the beams 15 to be locked in position relative to the beam 9.

The locking mechanism is illustrated in more detail in Figure 4 and comprises a pin 17 provided with an eye 19 at a free (lower) end thereof and spring biasing means 21 urging the pin to a position in which it locks the beam 15 relative to the semi-circular beam 9. As with the beam 13, the beams 15 are generally I-shaped in cross section to each support at least one fall arrest device (not shown) of conventional design in a manner such that the fall arrest device can be moved along the length of the beam 15.

In use of the fall arrest system illustrated in Figure 1, an aeroplane or the like is positioned beneath the horizontal beams 7 and the semi-circular beam 9 and elongate beam 13 are moved horizontally to position the elongate beam 13 above the fuselage of the aircraft and the semi-circular beam 9 above the wings of the aircraft. The beams 9 and 13 are then locked in position relative to the beams 7. A person working on the fuselage of the aircraft can then secure himself to a fall arrest device mounted for longitudinal movement along the beam 13 and can perform maintenance work on the fuselage or tailplane of the aircraft, positioning the fall arrest device appropriately along the longitudinal length of the beam 13, in the knowledge that any fall will not result in a swing that could give rise to injury.Similarly, a person working on one of the wings of the aircraft can position and lock in place the appropriate beam 15 at a suitable angle relative to the beam 13 for him to work at a desired location on the wing. The beam 15 is released from its locked position by pulling downwardly on the eye 19 and the beam is moved to the desired position and the eye is released allowing the pin 17 to be urged by the spring 21 into one of a number of apertures (not shown) provided in the semi-circular beam 9.

In the case of the military aircraft illustrated in Figure 1, the angle of the beam 15 can be adjusted in dependence upon whether the wing is swept back or not, while in the case of a civil aircraft, the angle of the beam 15 can be adapted to the angle of the wing of the aircraft, or at least that part of the wing on which it is desired to work.

The person working on the aircraft wing can then secure himself to a fall arrest device mounted for longitudinal movement along the beam 15 and can perform maintenance work on the aircraft wing, positioning the fall arrest device appropriately along the longitudinal length of the beam 15, in the knowledge that any fall will not result in a swing that could give rise to injury.

In the fall arrest system illustrated in Figure 5, the semi-circular beam 9 is mounted in a framework 23 which is itself mounted a movable manner between the two spaced, parallel horizontal beams 7 in the manner previously shown and described in relation to Figures 1 and 2. In the embodiment of Figure 5, two elongate beams 13a and 13b are provided to permit maintenance work to be carried out more safely on each side of the fuselage of the aircraft and the pivotable beams 15 are each mounted on one of the elongate beams 13a, 13b as illustrated.

Figure 6 shows the framework 23 of the fall arrest system of Figure 5 independently of the horizontal beams 7.

As can be seen from Figure 6, the framework 23 is provided with rollers 25 in order that the framework 23 is movable laterally of the hangar, as shown by the arrows in Figure 6, to a desired position and can then be secured in that position, with the rollers 25 being received in the horizontal beams 7.

Figure 7 shows the use of beams 27 of hollow box section instead of I-shaped beams as described previously for the beams 13 and 15. An enclosed runway track 29 is secured, for example by welding, to the underside of the hollow box section and carries therein at least one suspension trolley 31, such as a 4-wheel suspension trolley. The or each suspension trolley 31 can run the entire length of the beam so as to move with a worker as he moves along the fuselage or wing of the aircraft. A fall arrest device (not shown) is in use secured to an aperture 33 provided in the or each suspension trolley.

Clearly numerous modifications can be made to the present invention as described. The length of the various beams can be adapted to the size and type of aircraft to be maintained. The extent of the arcuate beam can also be varied to suit the size and type of aircraft to be maintained. For example, the beam could extend over 270 degrees or a full 360 degrees if desired. However, as a further alternative, the fall arrest system could be made in more than one movable component, for example in two parts each of which carries an arcuate beam extending over, say, 90 degrees. In this way, the two parts can be moved independently and can be positioned at any suitable point relative to the aircraft to be maintained. Additionally, by providing suitable beams extending longitudinally of the hangar or the like, or by providing alternative suspension means, it is possible to arrange for the fall arrest system to be movable in the longitudinal direction of the hangar or the like in addition to being able to move in the lateral direction.

Claims

1. A fall arrest system comprising an arcuate beam adapted to be positioned above an object, a pivotable beam mounted such that the free end thereof is supported relative to the arcuate beam, and a fall arrest device movable in the longitudinal direction of the pivotable beam.

2. A fall arrest system as claimed in claim 1, wherein the arcuate beam is mounted in a framework.

3. A fall arrest system as claimed in claim 2, wherein the pivotable beam is mounted in a pivotable manner in the framework.

4. A fall arrest system as claimed in any prceding claim, wherein the pivotable beam is adapted to be secured in position relative to the arcuate beam.

5. A fall arrest system as claimed in any preceding claim, wherein the arcuate beam is movable relative to the object.

6. A fall arrest system as claimed in claim 5 and including means adapted to lock the arcuate beam in position relative to the object.

7. A fall arrest system as claimed in claim 5 or 6, wherein the arcuate beam is movable in two directions arranged substantially at right angles.

8. A fall arrest system as claimed in any preceding claim and including a rectilinear beam provided with a further fall arrest device movable in the longitudinal direction thereof.

9. A fall arrest system as claimed in claim 8, wherein two rectilinear beams are provided arranged parallel to and spaced apart from each other.

10. A fall arrest system as claimed in claim 8 or 9, wherein a pivotable beam is mounted to each side of the rectilinear beam, or to each side of the parallel arrangement of two rectilinear beams.

11. A fall arrest system as claimed in claim 10, wherein the axis of pivoting of the pivotable beams corresponds substantially with the longitudinal axis of the rectilinear beam(s).

12. A fall arrest system as claimed in any preceding claim, wherein the arcuate beam extends over substantially 180 degrees.

13. A fall arrest system substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.