GB2461364A

GB2461364A - Safety cable bracket and slidable clip for lifeline which can bypass bracket without lifeline disconnection

Info

Publication number: GB2461364A
Application number: GB0907059A
Authority: GB
Inventors: James Attwood
Original assignee: HY SAFE IND PRODUCTS Ltd
Current assignee: HY SAFE IND PRODUCTS Ltd
Priority date: 2008-07-05
Filing date: 2009-04-24
Publication date: 2010-01-06
Anticipated expiration: 2029-04-24
Also published as: GB2461364B; GB0907059D0; GB0812369D0

Abstract

Safety apparatus comprising a cable 12, a plurality of brackets 14 formed from a single web of folded materiel, preferably steel, which has a tubular tunnel 18 for the cable, and secures the cable to structural parts 15, a clip 13 slidable along and securable to the cable and a tether 10 for attachment of the clip to the harness 11. Preferably the tunnel has chamfered ends and the bracket has a base 19 comprising a main part and a flange with both parts having at least one aperture for securement to a support. Preferably there is a bent limb connected to the bracket base on the opposite side to the flange. In one embodiment 16 the bracket pivots on a box like support, so it can be accessed from both sides of a support 17. Preferably the clip has a fixed jaw and a movable jaw for engagement and disengagement from the cable.

Description

SAFETY APPARATUS

This invention relates to improvements in safety apparatus for providing security against falling for workers operating on elevated sites such as tall buildings, building scaffolds and the like.

Prior Art

W091/17795 (BARROW HEPBURN SALA LTD) describes a safety apparatus wherein an overhead cable is suspended by brackets from a higher level structure, and a safety line or tether attached to a harness worn by a worker, is allowed to slide along the cable by means of a clip comprising a cylindrical body having a slot which enables the clip to pass over the brackets. The brackets each include a tubular part, through which the cable passes, with a neck connecting the tubular part to the main body of the bracket.

The slot in the cylindrical body of the clip can pass the neck whilst being too narrow to allow the cable to be pulled out through the slot, thus keeping the clip secure on the cable.

GB-A-2,370,3 12 (TJNILINE SAFETY SYSTEMS LTD.) discloses a clip, which would be suitable for use in the safety apparatus of the above specification. The clip similarly comprises a cylindrical body, with a slot defined between two jaws. The jaws are however articulated by means of a pivot pin opposite the slot. Opening of the jaws enables the clip to be engaged on, or removed from the cable, and the jaw is locked to prevent accidental disengagement, by sideways (axially of the clip) sliding of a member of one jaw in a slot in the other jaw.

GB-A-2,388,148 (SAFELNE UK LTD), discloses a modified clip featuring an outer slotted tubular part, with a slot wide enough to allow disengagement from the cable, and an inner slotted tubular part, also with a slot sufficiently wide to allow removal ofthe cable. The two parts are relatively rotatable to bring the slots alternatively into full alignment for engagement/disengagement, or into partial alignment to provide a reduced width slot which is sufficient to pass a support bracket web, but not the cable. The inner and outer parts are securable against accidental opening by being relatively slidable into and out of a latched position which may be secured by a clip or karabiner passed through alignable apertures.

Summary of the Invention

It is an object of the invention to provide a safety apparatus for use in providing security against falling which is improved with respect to such prior systems, and in particular with respect to economy and simplicity in manufacture and use, and is suitable for use with both horizontally and vertically deployed safety cables.

According to the invention, safety apparatus comprises a cable, a plurality of brackets for securing the cable to structural parts, a clip slidable along and securable to the cable, and a tether for attachment of the clip to a safety harness for wear by the user, characterised in that each bracket is formed from a single web of material, folded to the required configuration, and that the bracket provides a tubular tunnel for the cable.

The tunnel may be a tubular member having chamfered ends to aid sliding of the clip.

The bracket is preferably formed by folding from a sheet of a suitable grade of steel, and may provide a base providing one or more apertures for securing to a support, preferably on orthogonal axes, and a limb for carrying the tunnel and hence the cable with a clearance from the base.

The base may preferable comprise a main part, and a flange at right angles thereto, each provided with one or more apertures for securement by bolts or the like to a support. The limb may connect to the base at the side thereof opposite to the flange, and incorporate a band to import a degree of resilience to the bracket.

In an advantageous embodiment, a bracket may comprise a tunnel on a free edge of an angled member, the opposite end ofwhich is formed with a similar tunnel inserted in a shaft which extends between end members of a box like member so as to be rotatable thereon. The box like member may have a stop member at each open side, parallel to the shaft, to limit the arc through which the angled member may be rotated on the shaft. The stop members may each be constituted by a similar shaft extending between the end members, or by an upper edge of a side wall which may be lower than the end walls.

The pivotal mounting ofthe angled member enables the cable to be engaged from each side of the support.

The clip, in place of the pivotal opening and closing movement of its jaws, may include means for moving ajaw portion laterally to affect opening and closing ofthejaw, for engagement with, and disengagement from, the cable.

Onejaw ofthe clip may be fixed, together with an inner part of the otherjaw, and an upper plate of a lug providing an aperture for connection of a Karabiner or other hook for a tether. A lower end of the said other jaw may be adapted to be displaceable, radially of the clip, that is towards and away from the opposite jaw, together with a lower plate of the lug. One of the upper or lower plates may be provided with pins, which are adapted to engage in respective dog-legged slots in the other of the upper end lower plates, to enable the lower plate and jaw lower end to be displaced first to one side, and then away from the other jaw; for disengagement from the cable; or to carry out the reverse sequence of movements to close the jaws to prevent disengagement from the cable, but still leave a sufficient gap to pass over the brackets.

The clip jaws may define an elliptical passage, to match the preferred profile of the tunnel parts of the brackets.

The lower plate of the lug may be provided, at its edge which contacts the fixed upper part of the said otherjaw, above the moveable part, with a rib or nose which enters a locating groove on the jaw member.

The cable may be located in such a way as to provide either horizontal or vertical security lines, or for stairways and ladders, an inclined line. The cable may be provided above head height, at shoulder height or waist height, etc as required at the particular site.

The clip will of course in use be connected by a Karabiner or other appropriate connector to a tether or line which is in turn connected to a harness or security belt worn by a user.

Description of Drawings

A preferred embodiment of security apparatus according to the invention will now be described by way of example with reference to the accompanying drawings, wherein:-Figure 1 is a diagrammatic view, illustrating the use ofa security apparatus according to the invention; Figure 2 is a perspective view of an embodiment of bracket used in the apparatus for supporting a security cable; Figure 3 is an end view of part of the bracket shown in Figure 2; Figure 4 is an end view of a second embodiment of bracket used in the apparatus, which enables use from either side; Figure 5 is a diagrammatic view of the bracket shown in Figure 5, illustrating the range of movement, and scope for positioning of the cable; Figure 6 is a perspective view of a second embodiment of cable supporting bracket; Figure 7 is a detailed end view of part of the bracket; Figure 8 is a plan view from above of the second bracket; Figure 9 is a partly sectional end view of a clip for attaching a tether line to the cable; Figure 10 is a view from below of an upper part of the clip; and Figure 11 is a view of the lower part of the clip.

A fall preventing security apparatus installation, in an elevated location such as the galleries of a scaffold installation on a construction site or other sites such as oil and gas platforms, comprises a tether 10 or safety line to be worn by each worker, connected by a clip to a safety belt 11, or other type of safety harness, including shoulder straps and full body harness if required. The end ofthe tether 10 remote fromthe connectionto the worker's belt is connected to a safety cable 12 by a clip 13. The cable 12 is carried at a desired height -say above head height, or at waist or shoulder height, along a gallery ledge or passageway by a plurality ofbrackets 14, which are secured to suitable supports such as scaffold poles 15.

The brackets 14 and clips 13 are configured so that the clips can pass over the connections of the cable to the brackets. The brackets may take the form of a series of simple fixed brackets 14, or in appropriate places, a pivotal or swinging bracket 16, which can be used on either side of a support, such as a fence 17.

Figure 2 illustrates an embodiment of simple fixed position bracket 14 which guides the cable 12 through a tunnel 18. The bracket is formed from a single sheet by bending and appropriate cutting out, and provides a base 19 with a back flange 20. Each of these parts are provided with a respective aperture 21, 22 for attachment to a horizontal or vertical support respectively. An upright web 23 is provided at the front of the base 19. The bracket is made by folding ofsheet metal to provide a double thickness, as seen in Figure 3. The tunnel is formed of a tubular element, having chamfered ends 25 to aid sliding of the clip 13.

Figures 4 and 5 show the swingable or pivotal bracket 16 in more detail. The bracket 16 comprises respective end walls 30, 31 connected by a base 32, which has appropriate apertures for mounting on a support. Three shafts 33, 34, 35 extend between the end walls across the bracket, and the centre one of these 34, carries a swingable part 36 which is connected rotatably to the shaft 34 by a tunnel arrangement 38 formed in the edge region of the part 36 in a manner identical to that employed in Figures 2 to 4 to pass the cable 12. The part 36 has an end portion 37, at an acute angle to the rest of the part, and this carries on its edge a tunnel arrangement 38 for the cable 12, which is identical in construction to the tunnel 18 described in relation to the bracket 14, above.

The part 36 can be pivoted to be accessible from either side of the bracket 16, through an arc defined by the shafts 33, 35 which serve as stops at earlier extreme of the positions enabling a user to cross from one side to the other. Side walls could of course be used instead to act as limit stops. Position 36a shows the extreme to the right-hand side ofthe pivotable part, from the left hand position shown in full-line. The cable 12 is thus deployable to either side of the support.

Figure 6 illustrates a second embodiment of simple fixed position bracket 114 which guides the cable 112 through a tunnel 118. The bracket is formed from a single sheet by bending and appropriate cutting out, and provides a base 119 with a back flange 120. Each of these parts are provided with a respective aperture 121, 122 for attachment to a horizontal or vertical support respectively. An upright web 123 is provided at the front of the base 119, which includes a sloped part 124 and a vertical part 125, which gives a degree of resilience or springiness to the bracket 114.

The upper edge of the vertical part 125 is adapted to form the tunnel 18 by dividing the edge region into a series of tabs, separated by slits. These tabs are then bent either to the right (tabs 126) or to the left (tabs 127) and then returned to the centre at the edge, in an elliptical arc. These thus bent tabs 126, 127 form a tunnel through which the cable 112 is passed. This construction can be effected from a single piece of sheet metal, in contrast to prior art brackets, where the tunnel was formed by bending sheet metal about a mandrel. Figures 7 and 8 show further views of the bracket.

Figures 9 to 11 illustrate the remaining component of the security safety apparatus, the clip 13 for securing a workman's tether to the cable, which is adopted for passing over the brackets 14 and 16 which support the cable. The clip 13 comprises a cylindrical body of elliptical cross-section, consisting of a fixed jaw 40, opposite to a handle 41, and a two-part jaw 42 which has an upper fixed part 42a connected to an upper plate 43 of the handle 41, and a lower movable part 42b which is connected to a lower plate 44 of the handle 41. The lower plate 44 has a pair of upstanding pins, 45, 46 on its upper surface which are received in a pair of L-shaped slots 47, 48 in the upper plate 43. By means of these, the lowerjaw part 42b can be disengaged and opened, first by moving upwardly (in the drawing), and then to the right, away from the fixed jaw 40 (this translates from the user's view point, to sliding from left to right and pulling down).

This opens and locks the gap between the jaws, allowing the clip 13 to be placed over, or removed from, the cable 12.

The lower jaw part 42a is closed again, by the reverse movement. In the closed position, which is shown in Figure 7, a gap is left which is wide enough to allow a sheet metal web, such as 23 of bracket 14, or 37 of bracket 16 to pass through. The sliding movement of the lowerjaw and handle lower plate 44 is facilitated by a rib or nose 49 on the end ofthe plate 44, which engages on a matching recess on the upper fixed jaw part 42a.

The elliptical space enclosed by the jaws is dimensioned so as to allow easy passage to a tunnel part such as 18 or 38 when the clip is passed over a bracket 14 or 16 as the user moves about in the protected area. The handle has an aperture 49 provided by alignable holes 50, 51 in the plates 41, 44 for secural of a Karabiner clip which is fully closed or opened by movement of the plates.

The safety apparatus according to the invention is economic in materials and easy to fabricate. The clip 13 is resistant to accidental disconnection, and cannot be partly disconnected by the Karabiner, due to the design of the opening and closing actions of the parts 44, 43 which completely closes the aperture 49, so that a worker's tether cannot be connected and supports such as 16 allow for improved flexibility of operation and deployment. The cable 12 may be deployed and supported in horizontal or vertical runs, and possibly also inclined runs for use in stair and ladder ways.

Claims

CLAIMS1. Safety apparatus comprising a cable 12, a plurality of brackets 14 for securing the cable to structural parts 15, a clip 13 slidable along and securable to the cable 12, and a tether 10 for attachment of the clip 13 to a safety harness 11 for wear by a user, characterised in that each bracket 14 is formed from a single web of material, folded to the required configuration and in that the bracket 14 provides a tubular tunnel 18 for the cable 12.
2. Apparatus according to claim 1, wherein the tunnel 18 comprises a tubular member with chamfered ends.
3. Apparatus according to claim ito claim 2, characterised in that the bracket 14 is formed by folding from a steel sheet and provides a base 19 providing one or more apertures 21 for securing to a support, and a limb 23 for carrying the tunnel with a clearance from the base 19.
4. Apparatus according to claim 3, characterised in that the base 19 comprises a main part and a flange 20 at right angles thereto, each of said parts being provided with one or more apertures for securement by fasteners, such as bolts, to a support 15.
5. Apparatus according to claim 3 or 4, characterised in that the limb 23 connects to the base 19 at the side thereof opposite to the flange 21 and the limb 23 incorporates a bend to import a degree of resilience to the bracket 14.
6. Apparatus according to claim 1, characterised in that a bracket 16 has a tunnel on a free edge of an angled member 36,37, the opposite end of which member is formed with a similar turn, having a shaft 34 therethrough, which extends between end members 30,31 of a box like member, so that the angled member 36,37 is rotatable therein.
7. Apparatus according to claim 6, characterised in that the box like member is provided with a stop member 33,35 at each open side, parallel to the shaft 34 to limit the arc through which the angled member 36,37 may be rotated on the shaft 34.
8. Apparatus according to claim 7, characterised in that the stop members 33,35 are each constituted by a shaft extending between the end member 30,31.
9. Apparatus according to any preceding claim, characterised in that the clip 13 includes means for moving a jaw portion 42b laterally to effect opening and closing of the jaw for engagement with, and disengagement from the cable 12.
10. Apparatus according to claim 9, characterised in that one jaw 40 of the clip 13 is fixed, together with an inner part 42a ofthe other jaw, and an upper plate 43 of a lug providing an aperture 49 for connection of hook means to attach a tether.
11. Apparatus according to claim 9, characterised in that either the upper plate 43 or a lower plate 44 is provided with pins 45,46 which are adapted to engage in dog legged slots 47,48 in the other of said plates, to enable the lower plate 44 and jaw portion 42h to be displaced first to one side, and then away from the other jaw for disengagement from the cable 12 or to carry out the reverse sequence of movement to close the jaws to prevent disengagement from the cable, while leaving a gap to pass over the brackets 14.
12. Apparatus according to claims 9, 10 or 11, characterised in that the jaws 40,42 of the clip 13 define an elliptical passage.
13. Apparatus according to claim 10, elliptical the lower plate 44 of the lug is provided at its contacts the fixed upper part 42a above the moveable part 42b, with a rib or nose 49 which enters a locating groove on the upper jaw part 42a.