EP4230571A1

EP4230571A1 - Safety apparatus and method for working platform

Info

Publication number: EP4230571A1
Application number: EP22174410.5A
Authority: EP
Inventors: James Alan SAMUEL; Christopher Mark HOULTON; Leslie Geoffrey DARBY; Eric Michael MORAN; Homer Dale KYLE Jr
Original assignee: Nationwide Platforms Ltd
Current assignee: Nationwide Platforms Ltd
Priority date: 2022-02-17
Filing date: 2022-05-19
Publication date: 2023-08-23

Abstract

Apparatus (1, 11, 21, 31) is provided for monitoring whether an operator working at height on a platform (121, 131) of a Mobile Elevated Work Platform (MEWP) has properly anchored his safety harness (41) and lanyard (43, 52, 61, 71) to the platform (121, 131). The apparatus (1, 11, 21, 31) is mounted to an anchor point (126, 127, 135) on the platform (121, 131). and has an aperture (6, 26, 33A, 33B) through which a connector such as a carabiner, snap-hook or the like (23, 45, 51, 68, 81, 91, 101) may be passed to connect the lanyard (43, 52, 61, 71) with the apparatus (1, 11, 21, 31). Electrical detectors (7) or switch arrangements (14, 27, 32) register the presence of the connector (23, 45, 51, 68, 81, 91, 101) within the aperture (6, 26, 33A, 33B), and send a signal to a lamp (28) or audible alerting means to indicate whether the operator is safely anchored. The signal can also be used to operate a control switch within a control panel (128, 138) on the platform (121, 131) to prevent operation of the control panel (128, 138) to move the platform (121, 131). The apparatus comprises cover means (3) enclosing the aperture means when closed and openable to provide access to the aperture means , the cover means (3) being connected to the control switch means which acts to prevent operation of the control means (128, 138) when the cover means (3) is closed.

Description

The present invention relates to apparatus to monitor the attachment of safety harness to an anchor point and the like. More particularly but not exclusively, the invention relates to such apparatus for use on mobile elevated work platforms to monitor anchoring of safety harness and to take action if the safety harness is not suitably anchored.
It is clearly highly desirable for those working at height on Mobile Elevated Work Platforms (MEWPs) to be protected from falls. The IPAF Global MEWP Safety Report has shown that during the operation of boom type MEWPs (also known as "cherry-pickers") and other equipment involving working at height, falling from heights leads to the biggest number of fatalities.
All boom operators are now required to wear a fall restraint harness during the full range of operation. This is because the falling risks are present not only while working at height, but also during travelling conditions as the boom is elevated or lowered, given the cantilever/catapult effect resulting from the operator's location relative to the chassis of the MEWP apparatus.
The compulsory wearing of fall restraint harness is not at present mandated for scissor lift MEWPs in the UK, although a rise in compulsory harness policies is being seen across UK construction sites. The number of falls from scissor lifts is significantly lower than for boom type MEWPs, but wearing harnesses would still be beneficial in many situations, even where the risk might be more of injury than death.
Another issue has been observed, which lessens the effectiveness of fall restraint harnesses. This is the tendency of a number of operators to use inappropriate or non-designated anchor points for their harnesses, such as looping connectors around a hand rail or other fixture on the platform. These fastenings may not be sufficient to resist possible imposed stresses, for example if the harness is retaining an operator who has fallen from the platform.
Worse, there are still a few overconfident operators who do not believe that they need full safety equipment and that it interferes with their freedom of action. They may be tempted to operate the MEWP platform without wearing or anchoring their safety harnesses, or to disconnect their harnesses from the anchor point on the platform for greater convenience, once out of sight of the ground. Despite the potential consequences, this does still occur.
It is also possible that the harness might accidentally not be attached correctly or might not be attached at all due to the operator forgetting. It is also possible that an anchored harness might become disconnected from the anchor point accidentally,
It is both legally and morally the responsibility of those managing work at heights to take all actions necessary to ensure that the necessary safety equipment is worn and used correctly, for the sake of the safety of the operators. It is clear that it is not sufficient to rely solely on the operators' own actions to ensure safety.
It is hence an object of the present invention to provide equipment to detect correct attachment of safety harnesses to dedicated anchor points on MEWP platforms and the like, and to notify operators and others if the safety harness is not correctly anchored. It is a further object of the present application to provide such equipment that also interrupts functions of the MEWP if the safety harness is not correctly anchored.
According to a first aspect of the present invention, there is provided apparatus for monitoring the correct use of a safety harness connectable to a platform of a Mobile Elevated Work Platform (MEWP) or the like, comprising aperture means adapted to receive connector means of the safety harness engagingly, detector means adapted to detect absence or presence of the connector means engagingly received within the aperture means, and audible and/or visible alerting means operatively connected to the detector means and to control means on the platform of the MEWP, wherein said alerting means is activated when the control means is operated to move the platform without said connector means being engaged with said aperture means.
Preferably, the apparatus for monitoring the correct use of a safety harness comprises control switch means, operatively connected to the detector means and to the control means for the platform, wherein said control switch means acts to prevent operation of the control means to move the platform without said connector means being engaged with said aperture means.
Advantageously, the alerting means is located on the platform, optionally mounted to the control means of the platform.
The apparatus may comprise alerting means connected to a non-elevating control means for the platform of the MEWP, activated when the control means on the platform is operated without said connector means being engaged with said aperture means.
Optionally, the apparatus comprises remotely-located mobile alerting means, activated when the control means on the platform is operated without said connector means being engaged with said aperture means.
Alternatively or additionally, the alerting means comprises wireless communication means adapted to transmit visual and/or audible alert means to a mobile telephone, portable radio receiver or transceiver, computing means or the like.
In a preferred embodiment, the apparatus comprises means to mount it to an existing harness anchor point of the platform, optionally being detachably mountable thereto.
In an alternative embodiment, the apparatus is an integral part of a harness anchor point of the platform.
Preferably, the detector means comprises electromagnetic detection means.
The detection means may then comprise induction loop means mounted to the aperture means such that an inductance of the induction loop means is altered by the absence or presence of the connector means of the harness within the aperture means.
Alternatively, the detector means comprises mechanical detection means.
The detection means may then comprise one or more displaceable contact elements each operatively connected to switch means, wherein the or each said contact element is displaceable by the presence of the connector means of the harness within the aperture means, thus operating a respective switch means.
Said switch means may comprise electrical switch means.
Alternatively, said switch means may comprise pneumatic or hydraulic switch means.
The platform could then be employable in a zone potentially having a flammable or explosible atmosphere.
Preferably, the apparatus comprises cover means enclosing the aperture means when closed, said cover means being openable to provide access to the aperture means for the connector means of the harness.
Advantageously, said cover means is operatively connected to the control means and the control switch means, and the control switch means acts to prevent operation of the control means to move the platform when the cover means is closed.
The apparatus may comprise a plurality of aperture means and corresponding detector means, each detector means being operatively connected to the control means, the alerting means and the control switch means.
The apparatus may thus act to activate the alerting means if any of the plurality of aperture means does not have a respective safety harness connected thereto.
The apparatus may act to activate the control switch means to prevent operation of the control means to move the platform, if any of the plurality of aperture means does not have a respective safety harness connected thereto.
The apparatus may comprise load gauge means, operatively connected to the control means, the alerting means and the control switch means, adapted to operate when a load on the apparatus has exceeded a pre-set load limit, so as to activate the alerting means and/or the control switch means.
The load gauge means is thus adapted to provide an alert and/or to cause the control switch means to act to prevent operation of the control means to move the platform.
The apparatus may comprise a removable core module having integral power supply means and optionally comprising means to communicate with the alerting means and/or control switch means.
In a second aspect of the present invention, there is provided control panel means for a platform of a MEWP comprising apparatus for monitoring the correct use of a safety harness as described in the first aspect above.
In a third aspect of the present invention, there is provided a Mobile Elevated Work Platform comprising control means for a platform thereof as described in the second aspect above.
In a fourth aspect of the present invention, there is provided a method of improving safety of operators working at height on MEWPs and the like, comprising the steps of providing one or more monitoring apparatus as described in the first aspect above, mounting said apparatus to anchor points on an elevating platform of a MEWP, and operatively connecting the apparatus to alerting means, such that engagement of connector means of safety harness with aperture means of said apparatus activates said alerting means.
Preferably, said method further comprises the step of operatively connecting the apparatus to control switch means of a control panel on the platform, such that engagement of connector means of safety harness with aperture means of said apparatus operates said control switch means to permit operation of the control panel to move the platform.
Embodiments of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which:

Figure 1 is a schematic elevation of a first monitoring apparatus embodying the present invention, in a closed configuration;
Figure 2 is a schematic elevation of the monitoring apparatus of Figure 1, in an open configuration;
Figures 3a and 3b are schematic elevations of a mechanism of a second monitoring apparatus embodying the present invention, in a non-operating configuration and an operating configuration respectively;
Figure 4 is a schematic perspective view of a third monitoring apparats embodying the present invention, with a carabiner for connection thereto;
Figure 5 is a schematic elevation of a mechanism of a fourth monitoring apparatus embodying the present invention;
Figure 6a and 6b are frontal and rear elevations respectively of a safety harness and lanyard for use in the present invention;
Figure 7 is a scrap perspective view of a snap-hook connectable to any of the monitoring apparatus of the present invention, mounted to a lanyard;
Figure 8 is a perspective view of a lanyard for use with the safety harness of
Figures 6a and 6b, fitted with a proprietary connector;
Figure 9 is a perspective view of an adjustable lanyard for use in the present invention, fitted with two carabiners;
Figures 10 to 13 are elevations of four existing carabiners and snap-hooks usable with the monitoring apparatus of the present invention;
Figure 14 is a scrap perspective view of a first platform of a MEWP, fitted with two different forms of anchor point for receiving a monitoring apparatus of the present invention;
Figure 15a is a scrap perspective view of a second platform of a MEWP, fitted with a third form of anchor point for receiving a monitoring apparatus of the present invention; and
Figure 15b is a scrap perspective view of one of the anchor points of Figure 15a.

Referring now to the Figures of the accompanying drawings, and to Figures 1 and 2 in particular, a first monitoring apparatus 1 comprises a fastening loop 2 by which it may be mounted to a secure anchor point provided on a platform of a Mobile Elevated Work Platform (MEWP) - details of which are shown in Figures 14 to 15a and described below. The monitoring apparatus may be attached to the anchor point by means of any conventional shackle, snap-hook, link or the like, having a suitable strength rating (the entire system should be capable of handling an imposed force of 75kN, so each link between the MEWP and a safety harness worn by an operator should be able to take at least a force of 75kN).
The monitoring apparatus 1 has two covers 3 that together enclose its operative components in a closed configuration, as shown in Figure 1. Each cover 3 is pivotable about a pivot pin 4 mounted to a main body 5 of the monitoring apparatus 1 into an open configuration, as shown in Figure 2. Preferably, these covers 3 are manually pivotable between configurations. Alternative embodiments can use sliding covers in place of the pivotable covers 3 shown herein. In each case, the covers may be biased closed with a spring arrangement if preferred.
In the open configuration of Figure 2, the opened covers 3 reveal a circular aperture 6 extending through the main body 5 of the monitoring apparatus 1, through which a carabiner, snap-hook or the like may be passed and fastened, thus connecting a lanyard of a safety harness (see below) securely to the monitoring apparatus 1 and thence to the anchor point and the MEWP platform.
In this monitoring apparatus 1, the monitoring function is provided by a conductive ring 7 extending around a circumference of the aperture 6. This ring 7 has a significant inductance when connected to an electrical circuit. However, when a metal object such as a carabiner or hook is located within the aperture 6 and the ring 7, it significantly alters the inductance of the ring 7 and so disrupts the electrical circuit, thus generating an electrical signal to indicate the presence of the carabiner/hook safely engaged with the monitoring apparatus 1.
This signal can be used to activate an indicator lamp to confirm safe engagement, located on the monitoring apparatus 1 itself, on a control panel on the MEWP platform, on a control panel located on a base element of the MEWP at ground level, or on another ground station. To pass the signal to the control panel, an electrical cable (not shown) extends from the monitoring apparatus 1 to the control panel, and there will be existing data transfer connections between the control panel on the platform and the control panel at ground level. Further transmission beyond this point is most easily by wireless telecommunication methods, in formats including Bluetooth, GSM, MMS, SMS and email. It would thus be possible to transmit data regarding connection or disconnection to a remote device in the control of a responsible person for recording and possible subsequent investigation. Telematics and Internet of Things systems could be employed in this respect.
In preferred versions of the invention, the monitoring apparatus 1 does more than just indicate whether or not there is a secure physical connection to the monitoring apparatus 1 and the anchor point. In these versions, the monitoring apparatus 1 is connected to a switch element within the control panel on the platform, and this switch element acts to prevent operation of this control panel to move the platform, by an operator on the platform, unless the monitoring apparatus 1 is indicating that the carabiner or other hook is currently engaged. (Note: the control panel at ground level remains operable, so that the platform can be returned to ground level whether or not an operator on the platform is safely connected to the monitoring apparatus 1).
As an additional level of safety, the manually openable covers 3 can also be fitted with position sensors, which send out a signal when the covers 3 are open. In this case, the indicator lamp is lit, the control panel on the platform is allowed to operate to move the platform, and so forth, only when the covers 3 are open and there is a metal connector engaged with the aperture 6.
Other detection technologies that could be used in a monitoring apparatus of similar geometry include magnetic or optical detectors. The presence of a ferrous metal hook, etc, within the aperture 6 will affect the (electro-)magnetic fields within the ring 7. Changes in the magnetic field can be processed in much the same way as the change in inductance described above.
An optical sensor can be aimed across the aperture 6, such that its field of view is blocked by a hook, etc, extending through the ring 7. It may be necessary to provide a laser beam projected across the aperture 6 to ensure that there is sufficient contrast between what the optical sensor detects when there is nothing within the ring 7 and when there is a hook extending through the ring 7.
Turning now to Figures 3a and 3b, a mechanism of a second monitoring apparatus 11 is shown. There is a generally U-shaped frame 12, with a cylindrical roller 13 extending across the open end of the frame 12. A T-shaped slider 14 is located within the frame 12, and in the non-operating configuration shown in Figure 3a, a cross-bar of the T shape 14 contacts the roller 13, while a shaft of the T shape 14 extends down a midline of the frame 12 away from the roller 13. A mechanical switch element 16 extends from each side of the frame 12 to contact a tip 15 of the shaft of the slider 14. Each switch element 16 is connected to an associated detection unit 17 mounted to an outer face of the frame 12.
As shown in Figure 3b, a hook 18 or the like can be pushed between the roller 13 and the slider 14, thus opening up an aperture between them. The hook 18 can then be locked around the roller 13. The insertion of the hook 18 and opening of the aperture displaces the slider 14 away from the roller 13. This causes the tip 15 of the slider 14 to push the switch elements 16 aside, which is registered by the respective detection units 17, which in turn send a signal to the indicator lamp, the switch element within the control panel on the platform, and so forth, as for the first monitoring apparatus as described above.
Although they are omitted for clarity, covers 3 similar to those described for the first monitoring apparatus 1 may be incorporated into the second monitoring apparatus 11. Such covers 3 may be fitted with position sensors, so that the second monitoring apparatus 11 also only indicates safe connection to the monitoring apparatus 11 when the covers 3 are open and there is a hook 18 engaged around the roller 13, displacing the slider 14.
Although direct electrical connections to transmit signals are described above, other communications connections can be used. As well as using wireless telecommunications arrangements in place of some or all of the hard-wired electrical connections set out above, pneumatic or hydraulic connections can be used. These would be of particular use if the MEWP is intended for use in a flammable atmosphere where electrical arrangements might cause a spark. Mechanical connections to transmit signals are also possible - for example Bowden cables.
Turning now to Figure 4, a third monitoring apparatus 21 is shown, also employing a mechanical detection arrangement. This monitoring apparatus 21 has a main body 25, to which is mounted a fastening loop 22, by which it may be mounted to an anchor point on the platform. There is an electrical cable 24 leading from the monitoring apparatus 21 to the control panel on the platform.
This third monitoring apparatus 21 has an aperture 26 extending through its main body 25 somewhat similar to the first monitoring apparatus 1, but it detects the presence of a hook or carabiner 23 using mechanical switches 27 mounted around the circumference of the aperture 26. Each of these switches 27 is displaceable radially outwardly by a hook or carabiner 23 disposed through the aperture 26, thus operating a switch mechanism that produces a signal to indicate that the hook/carabiner 23 is securely present. In the particular embodiment shown in Figure 4, the switches 27 have a generally triangular form, expect that each has its corner directed towards an interior of the aperture 26 truncated, so that the switches 27 between them define a smaller circular gap to simplify insertion of the hook/carabiner 23.
This particular embodiment of the third monitoring apparatus 21 is provided with two warning lights 28 to indicate alternatively when the hook/carabiner 32 is safely engaged through the aperture 26 and when it is not.
The third monitoring apparatus 21 is shown without covers 3 to enclose the aperture 26 when not in use, but these can be provided if desired. As above, where there are covers 3 present, they can be fitted with position sensors and then the switch element in the control panel on the platform will only permit operation when both the covers 3 are open and the hook or carabiner 23 is engaged with the switches 27.
Figure 4 also shows a typical carabiner 23 suitable for engagement with the aperture 26 of the monitoring apparatus 21, and other monitoring apparatus 1, 11, comprising a frame 29 with an inwardly deflectable spring-loaded gate 30.
Figure 5 shows a mechanism of a fourth monitoring apparatus 31. This comprises two flat plates 32 extending in contact or adjacent each other. A forward plate 32 has an aperture 33A extending through it, and a rear plate 32 has a similar aperture 33B, but the two apertures 33A, 33B are not aligned in the default configuration of the plates 32. There is a small overlap between the apertures 33A and 33B, allowing part of a hook, carabiner or other fastening device to be inserted through both. This will displace the frontal plate 32 relative to the rear plate 32, as shown by the arrow. Preferably, the frontal plate 32 is spring loaded to return to its original position once there is no hook, carabiner 23 or the like holding the apertures 33A, 33B in alignment.
As well as a portion surrounding the aperture 33A, the frontal plate 32 comprises two lateral projections 34 and an elongate portion 35 extending away from the portion of the plate 32 with the aperture 33A. The lateral projections 34 interact with a frame (not shown) similar to the frame 12 of the second monitoring apparatus 11 described above, to guide the motion of the plate 32. The elongate portion 35 has a pair of triangular notches 38 located along its opposite lateral edges, and a respective switch element 36 extends into each notch 38 when the frontal plate 32 is not displaced.
However, when the frontal plate 32 is displaced by aligning the two apertures 33A and 33B, the notches 38 are moved out of alignment with the respective switch elements 36, which are as a result deflected outwardly as they leave the respective notch 38. This deflection of the switch elements 36 is picked up by a respective detection unit 37 connected to each switch element 36, generating a signal which is usable to activate indicator lamps and to activate a switch element in the control panel on the platform to allow the control panel to operate, as set out above for the other monitoring apparatus 1, 11, 21.
Figures 6a and 6b show a typical safety harness 41 to be worn by an operator working on the platform of a MEWP. The harness 41 comprises a set of woven straps 42 and adjustable buckles to be worn fitting snugly around the torso and abdomen of the operator. A lanyard 43 (in this case comprising a rope or cable) extends from the harness 41 and has a snap-hook or carabiner 45 at its end remote from the harness 41. In conventional harnesses 41, this carabiner 45 would be attached directly to an anchoring point on the platform, but in the present invention, it is attachable to a monitoring apparatus 1, 11, 21, 31 which is in turn attached to an anchor point. In this embodiment, the lanyard 43 is attached to the harness 41 with a loop, snap-hook or carabiner 46 located in the middle of the operator's back, so as to minimise the chance of the lanyard 43 getting in the operator's way when working. Also, the lanyard 43 is provided with a doubled portion 44, looped around the carabiner 45 and back on itself, by which the lanyard 43 as a whole can be adjusted in length. Normally, the lanyard 43 is kept as short as possible, consistent with freedom of movement, to ensure that the operator physically cannot fall off the platform (it is always more desirable to prevent a fall than to arrest a fall in progress, as would be a possibility with a longer lanyard. It also helps to keep the lanyard out of the operator's way. Some lanyards incorporate inertia reel systems to keep the lanyard as short and taut as possible, but it is found that such systems do not always operate satisfactorily when an operator is carrying out all the movements involved in working from a MEWP platform.
Figures 7, 8 and 9 show features and examples of existing lanyards for safety harnesses 41. Figure 7 shows a typical snap-hook 51 with a hooked frame 49 and a pivotable gate 50 extending across remote ends of the frame 49, deflectable inwardly of the frame 49 to allow passage into its interior, but spring-loaded to close the frame 49 afterwards. The lanyard 52, here a rope or cable, is looped though a separate aperture on the frame 49.
Figure 8 shows a proprietary lanyard 61 comprising a woven strap 62 instead of a rope or cable. The lanyard 61 is adjustable in length by means of a doubled section 64, looped round a terminal carabiner 46 and held at a desired length with a constricting sleeve 63. The terminal carabiner 46 is suitable for connection to a safety harness 41 as shown in Figure 6b. At a remote end of this particular lanyard 61, there is a proprietary connector 65 comprising a flat profiled tongue 66, which is releasably inserted into a co-operating proprietary socket, locking the connector 65 in place. (For this connector 65, apparatus as shown above could be incorporated into the proprietary socket or mounted around a slot of the socket where the tongue 66 is to be inserted, probably with a change of aperture geometry to conform to that of the socket, rather than the aperture forms shown).
Figure 9 shows a versatile lanyard 71 which has a simple oval carabiner 68 at each end, comprising a frame 69 and a spring-loaded gate 70. This lanyard 71 comprises a rope, cable or cord 72, with a doubled section 74 at one end for length adjustment. The doubled section is formed by passing the cord 72 through a slide buckle 73, looping it through the adjacent carabiner 68, and securing the end of the cord 72 to the slide buckle 73.
Figures 10 to 13 show various forms of carabiner or snap-hook that can be used as connectors for safety harnesses and associated lanyards. Figure 10 shows what is known as a "termination connector" or Class T connector 81, which comprises a frame 79 forming most of a loop, and a spring-loaded gate 80 deflectable inwards of the frame 79 to allow the connector 81 to be engaged with something, but sprung to close the loop again once engagement is complete. There is a separate aperture 84 to receive a lanyard or the like. This form of connector 81 is useful to ensure that loading is in a particular direction.
Figure 11 shows a "basic" or Class B connector 91. This is a fairly standard carabiner-type connector, with a hooked frame 89 forming most of a loop and a spring-loaded gate 90 completing the loop when closed. This particular version has a sleeve on the gate that can be moved to enclose a junction between the frame 89 and the gate 90, thus preventing accidental deflection of the gate 90. Such connectors can also be made with a screw fitting to fasten a moveable end of the gate 100 to a respective end of the frame 99, in place of a simple co-operating hooks arrangement.
Class B connectors can be used almost anywhere in these systems as long as they have the right load rating.
Figure 12 shows a "multi-use" or Class M connector 101, which also comprises a hooked frame 99 and a deflectable gate 100 to complete the loop of the connector 101, the gate 100 here being fitted with a fastening arrangement as described above. However, in this Class of connector 101, an interior of the frame 99 is subdivided by a divider element 103 to produce a secondary aperture 104, for example to receive a lanyard. This allows a load to be directed on to major and minor axes of the connector 101
Figure 13 shows an "anchor connector", also known as a Class A connector or a Selbstschlieconnector 111. This also comprises a hooked frame 109 with a spring-loaded gate 110 to complete an enclosed loop, with a separate aperture 114 that can receive a lanyard. This form of connector 111 has its frame 109 shaped to engage more readily and securely with certain shapes of anchor point.
Turning now to Figure 14, this shows part of a MEWP platform 121 and examples of suitable anchor points 126, 127. The platform 121 is surrounded with a safety railing or cage 122, made up in conventional fashion from vertical 124 and horizontal 123 railing members. There is a control panel 128 for the platform 121 built into the cage 122, which is here shown with its cover closed for simplicity.
A first form of anchor point 126 comprises a diagonal strut, welded across a corner where vertical 124 and horizontal 123 railing members meet. This defines a triangular aperture with which a carabiner, snap-hook or other connector on an end of a lanyard can engage. As shown, these first anchor points 126 are best placed midway up the sides of the cage 122, maybe 50cm to 60cm above a floor of the platform. This keeps the lanyard from under the operator's feet, doesn't require the operator to bend far to fasten his lanyard to the anchor point 126, and provides a convenient geometry for the lanyard and harness to keep the operator safe within the cage 122.
A second form of anchor point 127 is also shown. This is a simple continuous metal loop or shackle 127 encircling a vertical railing member 124 and resting on top of a horizontal railing member 123. The carabiner, snap-hook or the like on the end of a lanyard can engage simply and securely with this loop/shackle 127. As with the first anchor points 126 described above, these second anchor points 127 are best located midway up a side of the cage 122.
Figures 15a and 15b show a second MEWP platform 131 fitted with a third form of anchor point 135. This MEWP platform 131 is also provided with a safety railing or cage 132 made up of vertical 134 and horizontal 133 railing members, with a control panel 138 for the platform 131 built into the cage 132. A foot-operated "dead man's switch" 139 of conventional form is mounted to a floor 137 of the platform 131 adjacent the control panel 138.
The third anchor points 135 comprise sheet steel welded to extend in a vertical plane between a vertical railing member 134 and a horizontal railing member 133, in a corner where they meet, preferably extending downwardly from the horizontal member 133. This anchor point 135 defines a rounded aperture 136, into which the carabiner, snap-hook or other connector from a lanyard can be inserted to engage with the anchor point 135. Again, the third anchor point 135 is best located midway up a side of the cage 132.
Thus, one of the monitoring apparatus 1, 11, 21, 31 described above can be attached securely to a respective anchoring point 126, 127, 135 on the cage 122, 132 of the respective MEWP platform 121, 131 and operatively connected to the control panel 128, 138 of the platform 121, 131. An operator wearing a safety harness and lanyard can then connect the lanyard to the monitoring apparatus, which will detect the carabiner, snap-hook, etc., of the lanyard and light up the indicator lamp to show that the operator's harness is securely anchored, and in most variants also allow the operator to operate the control panel to move the platform as desired.

Claims

Apparatus (1, 11, 21, 31) for monitoring correct use of a safety harness (41) connectable to a platform (121, 131) of a Mobile Elevated Work Platform (MEWP) or the like, characterised in that
the apparatus (1, 11, 21, 31) comprises aperture means (6, 26, 33A, 33B) adapted to receive connector means (23, 45, 51, 68, 81, 91, 101) of the safety harness (41) engagingly, detector means (7, 14, 27, 32) adapted to detect absence or presence of the connector means (23, 45, 51, 68, 81, 91, 101) engagingly received within the aperture means (6, 26, 33A, 33B), and audible and/or visible alerting means () operatively connected to the detector means (7, 14, 27, 32) and to control means (128, 138) on the platform (121, 131) of the MEWP, wherein said alerting means (28) is activated when the control means (128, 138) is operated to move the platform (121, 131) without said connector means (23, 45, 51, 68, 81, 91, 101) being engaged with said aperture means (6, 26, 33A, 33B).
Apparatus for monitoring correct use of a safety harness as claimed in Claim 1, characterised in that
the apparatus (1, 11, 21, 31) comprises control switch means, operatively connected to the detector means (7, 14, 27, 32) and to the control means (128, 138) on the platform (121, 131), wherein said control switch means acts to prevent operation of the control means (128, 138) to move the platform (121, 131) without said connector means (23, 45, 51, 68, 81, 91, 101) being engaged with said aperture means (6, 26, 33A, 33B).
Apparatus as claimed in either Claim 1 or Claim 2, characterised in that the apparatus (1, 11, 21, 31) comprises means (2, 22) to mount the apparatus to an existing harness anchor point (126, 127, 135) of the platform (121, 131), optionally to mount the apparatus (1, 11, 21, 31) detachably thereto.
Apparatus as claimed in either Claim 1 or Claim 2, characterised in that the apparatus (1, 11, 21, 31) is an integral part of a harness anchor point (126, 127, 135) of the platform (121, 131).
Apparatus as claimed in any one of the preceding claims, characterised in that the detector means (7) comprises electromagnetic detection means (7).
Apparatus as claimed in Claim 5, characterised in that
the electromagnetic detection means (7) comprises induction loop means (7) mounted around the aperture means (6) such that an inductance of the induction loop means is altered by absence or presence of the connector means (23, 45, 51, 68, 81, 91, 101) of the harness (41) within the aperture means (6).
Apparatus as claimed in any one of Claims 1 to 4, characterised in that
the detector means (14, 27, 32) comprises mechanical detection means (14, 27, 32) for the connector means (23, 45, 51, 68, 81, 91, 101).
Apparatus as claimed in Claim 7, characterised in that
the mechanical detection means (14, 27, 32) comprises one or more displaceable contact elements (14, 27, 32) each operatively connected to switch means (), wherein the or each said contact element (14, 27, 32) is displaceable by the presence of the connector means (23, 45, 51, 68, 81, 91, 101) of the harness (41) within the aperture means (26, 33A, 33B), thus operating the respective switch means (16, 36).
Apparatus as clamed in any one of the preceding claims, characterised in that
the apparatus (1, 11, 21, 31) comprises cover means (3) enclosing the aperture means (6, 26, 33A, 33B) when closed, said cover means (3) being openable to provide access to the aperture means (6, 26, 33A, 33B) for the connector means (23, 45, 51, 68, 81, 91, 101) of the harness (41).
Apparatus as claimed in Claim 9, characterised in that
said cover means (3) is operatively connected to the control switch means on the platform (121, 131), and the control switch means acts to prevent operation of the control means (128, 138) to move the platform (121, 131) when the cover means (3) is closed.
Apparatus as claimed in any one of the preceding claims, characterised in that the apparatus (1, 11, 21, 31) comprises a plurality of aperture means (6, 26, 33A, 33B) and corresponding detector means (7, 14, 27, 32), each detector means (7, 14, 27, 32) being operatively connected to the control means (128, 138), the alerting means (28) and the control switch means.
Apparatus as claimed in any one of the preceding claims, characterised in that the apparatus (1, 11, 21, 31) comprises load gauge means, operatively connected to the control means (128, 138), the alerting means (28) and the control switch means, adapted to operate when a load on the apparatus (1, 11, 21, 31) has exceeded a pre-set load limit, so as to activate the alerting means (28) and/or the control switch means.
Apparatus as claimed in any one of the preceding claims, characterised in that the apparatus (1, 11, 21, 31) comprises a removable core module having integral power supply means and optionally comprising means to communicate with the alerting means (28) and/or control switch means.
A control panel unit (128, 138) for a platform (121, 131) of a Mobile Elevated Work Platform, comprising apparatus (1, 11, 21, 31) for monitoring the correct use of a safety harness (41), as claimed in any one of the preceding claims.
A method of improving safety for operators working at height on MEWPs and the like, comprising the steps of providing one or more monitoring apparatus (1, 11, 21, 31) as claimed in any one of Claims 1 to 13, mounting said apparatus (1, 11, 21, 31) to anchor points (126, 127, 135) on an elevating platform (121, 131) of a MEWP, and operatively connecting the apparatus (1, 11, 21, 31) to alerting means (28), such that engagement of connector means (23, 45, 51, 68, 81, 91, 101) of a safety harness (41) with aperture means (6, 26, 33A, 33B) of said apparatus (1, 11, 21, 31) activates said alerting means (28).