GB2377966A

GB2377966A - safety apparatus for use with a fall arrest system

Info

Publication number: GB2377966A
Application number: GB0213037A
Authority: GB
Inventors: Stephen Murten
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-06-08
Filing date: 2002-06-07
Publication date: 2003-01-29
Anticipated expiration: 2022-06-07
Also published as: GB2377965B; GB0213037D0; GB0213030D0; GB2377966B; GB2377965A; GB2377964B; GB0113933D0; GB2377964A; GB0213032D0

Abstract

A safety apparatus comprises a lower support section (121, Figure 4) having a vertical slot, an upper support section (122, Figure 4) with a carriage at a lower end, the upper and lower sections being arranged telescopically such that the carriage is slidable in the slot and a pulley system which includes first and second pulley sets (601, 602, Figure 6) with first and second securing loops (622, 623, Figure 6) and a pulley rope (402), said pulley system providing an operative connection between the upper and lower sections such that the upper section moves relative to the lower section when a rope is pulled in the direction of the movement (402). Preferably the apparatus includes a cable connection plate (Figures 2 and 3) arranged to rotate about the upper support section.

Description

2004-P112-GB 2377966

Safety Apparatus Safety apparatus for the erection of structures is disclosed in international patent publication number WO 01/27411 in the name of the 5 present applicant. The safety apparatus has a first substantially vertical support, a second substantially vertical support and a supporting cable extending between the first and second supports. The vertical supports are configured to adjustable in length and each include a first fixing means and a second fixing means such that the length of the support may be adjusted to by releasing the first fixing means and then refixing the first fixing means after the adjustment has been made. In this way, it is possible to adjust the height of the safety apparatus while erection is taking place such that work may be carried out in safety at substantially all times.

According to a fist aspect of the present invention, there is provided safety apparatus comprising a substantially vertical support having an upper section telescopically receivable within a lower section, wherein telescoping is effected by transfer of rope from a first pulley system to a second pulley system.

The invention will now be described by way of example, with so reference to the accompanying drawings of which: Figure 1 shows operatives connected to safety apparatus whilst erecting a scaffold structure; Figure 2 shows a cable connection plate; Figure 3 shows a cable connection plate in motion; z Figure 4 illustrates adjustment of the support system; Figure 5 shows the operation of a pulley system; Figure 6 shows a schematic representation of the pulley system

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identified in Figure 5.

A scaffold 101 is shown in Figure 1, having vertical poles 102, horizontal poles 103, transversal poles 104 and flat sections 105, in addition the scaffold may also include diagonal strengthening poles.

5 A typical erection procedure firstly requires the erections of the vertical poles 102 followed by the fitting of horizontal poles 103. Transversal poles 104 are then implemented to confer additional stability and integrity to the scaffold before the flat sections 105 are put into place.

As described in the present applicant's published international patent o specification, erection of the scaffold is being performed using safety

apparatus consisting of a first substantially vertical support 111, a second substantially vertical support 112 and one or more supporting cables 113, 114 extending between the first support 111 and the second support 112.

The supports 111,112 are configured to be adjustable in length and each includes a first fixing means 115 and a second fixing means 116 such that the length of the support may be adjusted by releasing the first fixing means 115 and then refixing the first fixing means 115 after the adjustment has been made. While this adjustment takes place, the second fixing means 116 remains in place thereby ensuring that operatives are supported 20 at all times in case of a fall.

The first substantially vertical support 111 consists of a lower support section 121 and an upper support section 122. The lower support section 121 has a larger diameter then the upper support section 122, such that the upper support section may slide vertically within the lower support section 2s 121. The lower support section 121 is attached to transversal poles 104 and 123 by way of lower fixing members 124,125. The upper support section 1 2 is attached in a similar way as further sections to the scaffold

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are added, as described in the earlier referenced international patent application. In this way, as additional platform levels are added, the upper support section 122 may be held in place while the lower fixing members 124, 125 are released allowing the lower support section 121 to be raised 5 and reconnected at a higher height. Thus, in this way, the safety apparatus ascends the rising scaffold by extending its upper section and then contracting its lower section.

In the preferred embodiment, as shown in Figure 1, the vertical supports 111, 112 are circular in cross-section to facilitate their operation in to a telescopic manner so as to facilitate adjustment. In addition, cables and pulleys are provided to facilitate the movement of the telescoping devices vertically as the system ascends up the scaffold.

A problem with the system disclosed in the aforesaid international publication is that a fall in a direction away from the plane defined by the 15 supports and the cable may tend to apply a torsional force about the vertical axes of the supports. Torsional forces of this type will tend to apply a twisting effect upon the upper support, such as upper support section 122, with respect to the lower support, such as lower support section 121.

Thus, the vertical support provides more than adequate resilience to 20 compressive forces and bending forces but its integrity may be undermined if an excessive torsional force is applied.

The present preferred embodiment overcomes this problem by the provision of a rotating cable connection plate 131, as detailed in Figure 2.

25 Figure 2 The cable connection plate 131 is detailed in Figure 2. The connection plate 131 includes a cylindrical section 201, having a first

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I'. 2004-P112-GB... c extension portion 202 and a second extension portion 203. In this embodiment cables, such as cable 204 and cable 205 are secured to respective extension portions 202, 203 by means of extension portion orifices 206 and 207, although it should be appreciated that other forms of cable connection may be employed for this purpose, such as a loop.

During manufacture, the external profile of the upper support section 122 is raised by the application of a weld 208. The cylindrical portion 201 of the connection plate 131 slides freely over the upper support section 122 until it is forced into a rest position by means of weld 208. A similar weld to 209 is then applied to the upper support section 122 at a position above the cylindrical portion 201 of the connection plate 131.

After welds 208 and 209 have been applied, vertical movement of the cable connection plate 131 is restrained and the cable connection plate 131 is then held in place upon the upper support section 122. However, the 15 cable connection plate 131 is allowed to rotate around the upper support section 122, about the axis of the upper support section 122. In this way, if a fall occurs that applies force away from the previously described plane, the cable connection plate 131 will rotate with respect to the upper support section 122, such that when force is applied to the upper support section So 122 it takes the form of a bending force in preference to a torsional force.

Figure 3 In the example shown in Figure 3, a fall has occurred such that force is now applied to cable 205. A fall has occurred in such a way that a component of this force is being applied away from the previously described plane. Consequently, the cable connection plate 131 has rotated as illustrated by arrow gut. After the rotation has taken place, a bending

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force, illustrated by arrow 302 is applied to the upper support section 122.

The bending force is easily restrained by the vertical support 111 with torsional forces due to the fall being reduced significantly.

Figure 3 also illustrates how the extension portions 202 and 203 are butt welded to the cylindrical portion 201 at 303.

Figure 4 As scaffold is added in order to increase the height of the overall structure, the safety apparatus is firstly extended by extending upper support to section 122 with reference to lower support section 121. Upper support section 122 is then secured to ensure that force may safely be supplied to the support cables 113, 114 etc. As additional height is required, the lower fixing members 124, 125 are temporarily released while the upper support section 122 remains firmly secured to the scaffold. The telescopic system 5 then contracts resulting in the lower support section 121 rising up the structure to a new locating position.

The extension and contraction of the substantially vertical supports 111, 112 Is effected by manual operation of a pulley rope 401 as illustrated in Figure 4. With the lower support section 121 firmly held in place, an operative no pulls pulley rope 401 in an upwards direction resulting in the upper support section 122 ascending upwards with respect to the restrained lower support section 121. Thereafter, once extended to a required position, the upper support section 122 may be secured to the scaffold. Thereafter, further extension may be effected by releasing lower fixing members 124 and 125 s and then pulling pulley rope 401 in the direction opposite to arrow 402 in order to cause the telescoping assembly to contract. Thereafter, lower fixing members 1 4 and 125 may be secured at new positions and further

2004-P112-GB. r i extensions may be effected by further operation of the pulley rope 401 in the direction of arrow 402.

Figure 5 As shown in Figure 5, pulley rope 401 has been pulled in the direction of arrow 402 resulting in the upper support section 122 being extended by a greater degree than that shown in Figure 1. Thus, it can be seen that telescoping support in combination with a pulley system allows expansion and contraction of the telescoping assembly by manual operation of a single 10 rope without rope being pulled away from the assembly itself. Another way of looking at this is to consider that the pulley rope system used for effecting movement of the assembly does not present a rope end. Both ends are constrained within the system itself where movement occurs by reducing the distance between a first set of pulleys while increasing the distance between a second set of pulleys.

Figure 6 The pulley system identified in Figure 4 is shown diagrammatically in Figure 6. The totality of the pulley system includes a first pulley set 601 and a 20 second pulley set 602. The first pulley set 601 includes a first pulley subassembly 603 and a second pulley subassembly 604. The second pulley system 602 includes a third pulley subassembly 605 and a fourth pulley subassembly 606. The first pulley subassembly 603 includes a first pulley 611, and a second pulley 612. The second pulley subassembly 604 includes z a third pulley 613 and a fourth pulley 614. The third pulley subassembly includes a fifth pulley 615 and a sixth pulley 616. The fourth pulley subassembly Sue includes a seventh pulley 617 and an eighth pulley 6 g.

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The pulley rope extending between pulley 614 and 615, shown as 621 is that which is manually adjusted by an operative, as illustrated in Figure 4.

Movement of the pulley rope 621 in the direction of arrow 402, that is in an upwards direction, results in rope being transferred from pulley set 601 to pulley set 602 resulting in pulley subassembly 603 being brought closer to towards pulley subassembly 604. Similarly, as rope is supplied to pulley 615 more rope is introduced to pulley set 602 resulting in pulley subassembly 605 extending away from pulley subassembly 606. The overall result of this is that the mechanism extends with the upper support section 122 moving upwards.

10 Similarly, when the pulley rope is pulled opposite direction, rope is taken from pulley set 602 and returned to pulley set 601 such that the distance between pulley subassembly 605 and pulley subassembly 606 decreases resulting in the lower support section 121 rising to a new position by the telescoping and contacting of the support system. Thus, this is achieved without displacing rope from the overall system itself, which could result in rope damage or entanglement, while at the same time providing the mechanical advantage to the operative.

In a preferred embodiment, the pulley rope has a substantially nylon construction and a typical diameter of six millimetres. A hand rope grab may 20 be provided to assist an operative in adjusting the pulley rope. Pulley rope 621 is secured to pulley subassembly 604 by securing loop 622. The other end of pulley rope 621 is secured to pulley subassembly 605 by a second securing loop 623. From the first securing loop 622, the pulley rope 621 extends anticlockwise around pulley 612, anticlockwise around pulley 613, anticlockwise around pulley 611 and anticlockwise around pulley 614. Pulley rope 621 then extends to the third pulley subassembly 605 where it is wound clockwise around pulley 615, clockwise around pulicy 6'id, clockwise around

t,,. t 2004-P112-GB t pulley 616 and clockwise around pulley 617 for its other end to be secured at the second securing loop 623.

Claims

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Claims:

1.Safety apparatus for use within a fall arrest system comprising a first support section disposed within a second support section said second support section defining a slot extending along a portion of the length thereof said first support section having a carriage at a first end configured to be movable along said slot such that said first support section is in telescopic relation with said second support section; wherein to said safety device further comprises a pulley system configured to provide an operative connection between said first support section and said second support section said pulley system comprising a first pulley set having a first securing loop, a second pulley set having a second securing loop and a pulley rope said pulley rope being wound around said pulley system, having a first end secured to said first securing loop and a second end secured to said second securing loop, such that the length of rope received by said first pulley set and said second pulley set is adjustable according to an inverse relationship 2. Safety apparatus according to claim 1, wherein said first pulley set comprises a first pulley subassembly and a second pulley subassembly and said second pulley set comprises a third pulley subassembly and a fourth pulley subassembly, z said second pulley subassembly comprising said first securing loop and said third pulley subassembly comprising said second securing loop, said first and said fourth pulley subassemblies being located upon

2004-P 11 2-GB

said second support section and said second and said third pulley assemblies being located upon said first support section, such that the relative distance between said first and second pulley subassemblies and the relative distance between said third and fourth pulley subassemblies is 5 adjustable according to an inverse relationship, by means of adjusting said pulley rope 3. Safety apparatus according to claim 2, wherein said first pulley subassembly comprises a first pulley and a second pulley, said to second pulley subassembly comprises a third pulley and a fourth pulley, said third pulley subassembly comprises a fifth pulley and a sixth pulley and said fourth pulley assembly comprises, said first, fourth, fifth and eighth pulleys having a greater diameter than said second, third, sixth and seventh pulleys. 4. Safety apparatus according to claim 3, wherein said pulley rope extends from said first securing loop anticlockwise around said second pulley, anticlockwise around said third pulley, anticlockwise around said first pulley, anticlockwise around said fourth pulley, clockwise around said fifth So pulley, clockwise around said eighth pulley, clockwise around said sixth pulley and clockwise around said seventh pulley to said second securing loop. 5. Safety apparatus according to any preceding claim wherein as said pulley rope is a nylon rope o. Safety apparatus according to any preceding claim wherein

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said pulley rope has a diameter of six millimetres 7. Safety apparatus according to any preceding claim further comprising a hand operated rope grab configured to be used with said 5 pulley rope 8. Safety apparatus according to any preceding claim wherein said apparatus further comprises a cable connection plate configured to rotate around said first support section, said cable connection plate 10 comprising a cylindrical portion having at least one extension portion extending therefrom, said extension portion having a connection point 9. Safety apparatus comprising a pulley system as herein described with reference to and as shown in Figures 1 to 6.

10. Safety apparatus comprising a substantially vertical support having an upper section telescopically receivable within a lower section, wherein telescoping is effected by the transfer of rope from a fist pulley system to a second pulley system.