GB2377964A

GB2377964A - Safety apparatus with rotating cable connection plate

Info

Publication number: GB2377964A
Application number: GB0213030A
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; GB2377966A; GB0213037D0; GB0113933D0; GB2377964B; GB2377965A; GB0213032D0; GB0213030D0; GB2377966B

Abstract

A safety apparatus comprises a lower support section (121, Figure 1) having a passage therein and an upper support section (122) with a carriage at a first end thereof, the upper and lower sections configured such that the upper section is telescopically located within the lower with the carriage slidable in the passage, and a cable connection plate (131) including a cylindrical portion (201) with at least one extension portion (202, 203), having a connection point, preferably in the form of a loop or aperture (206, 207), extending therefrom, where the cable connection plate is configured to rotate around the upper support section. Preferably the cable connection plate is positioned between two welds (208, 209) on the upper support section. In the event of a fall the cable connection plate rotates to reduce the torsional force applied to the support setions.

Description

Safety Apparatus Safety apparatus for the erection of structures is disclosed in international patent publication number WO 01/27411 in the name of the 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 by releasing the first fixing means and then re-fixing 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 member, a cable extending from said support member and a cable connection means configured to attach said cable to said support and to rotate with respect to said support.

The invention will now be described by way of example, with 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; 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.

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 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 re-fixing 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 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 than the upper support section 122, such that the upper support section may slide vertically within the lower support section 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 122 is attached in a similar way as further sections to the scaffold 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

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 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 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 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.

Figure 2 The cable connection plate 131 is detailed in Figure 2. The connection plate 131 includes a cylindrical section 201, having a first 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 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 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 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 301. After the rotation has taken place, a bending 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.

Claims

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 passage 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 passage such that said first support section is in telescopic relation with said second support section; wherein said safety device further comprises a cable connection plate configured to rotate around said first support section and said cable connection plate comprises a cylindrical portion having at least one extension portion extending therefrom, said extension portion comprising a connection point.
2. Safety apparatus according to claim 1 wherein said connection point is an aperture
3. Safety apparatus according to claim 1 wherein said connection point is a loop
4. Safety apparatus according to claim 1 wherein said first support section is configured such that said cable connection plate rotates around a non-adjustable region of said first support section
5. Safety apparatus according to claim 2 wherein said cable connection plate is positioned between two weld portions on said first

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support section
6. Safety apparatus comprising a cable connection plate substantially as herein described with reference to and as shown in Figures 1 to 3
7. Safety apparatus comprising a substantially vertical support member, a cable extending from said support member and a cable connection means configured to attach said cable to said support and to rotate with respect to said support.