GB2388155A

GB2388155A - Safety line connecting hook

Info

Publication number: GB2388155A
Application number: GB0309436A
Authority: GB
Inventors: Michael James Smith; Graham Burnett
Original assignee: TOTAL ACCESS Ltd
Current assignee: TOTAL ACCESS Ltd
Priority date: 2002-05-02
Filing date: 2003-04-25
Publication date: 2003-11-05
Anticipated expiration: 2023-04-25
Also published as: GB0210096D0; GB2388155B; GB2388155A8

Abstract

A device 10 for attaching a safety line 20 to a bolt. The device 10 comprising a hook 16 engageable on the bolt and automatically closable by a spring loaded keeper 30 which can only be moved when a pivoted lock lever 34 has first been moved. The safety line 20 extends into a slot and has a loop 24 which engages around a load bar 22 extending across the slot. A pair of shear pins 28 are provided on either side of the slot 18 to substantially prevent pivoting of the line 20 about the bar 22 except where a sufficient lateral force is applied thereto for instance if a user may fall, which would cause a respective one of the pins 28 to shear.

Description

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Title: Connector DESCRIPTION

This invention concerns connectors for safety lines and in particular connectors for connecting safety lines to bolts extending from electricity pylons.

Electricity pylons as well as other structures have bolts or the like extending from them to which safety lines for workers can be attached. The safety line is usually attached to a connector that can lock onto the bolt or the like. A problem with known correctors is that the distance between the bolt and the safety line attachment point is too great, so that lateral forces on the connector due to a fall can compromise the cormector and even cause * to fail.

An object of this invention is to provide an improved safety line connector. According to this invention there is provided a device for attaching a safety line to a projecting structure comprising a body having a hook at one end and a pivotal attachment point for a safety line, wherein the safety line is constrained against pivoting about said pivotal attathrnent point by shearable means remote from the hook and spaced from the pivoting point, whereby shearing of the shearable means will permit said pivoting.

The body preferably has a slot in its end opposite to the hook and Me safety line attachment point is a bar or the like across the slot. Preferably, the bar or the like is in the same plane or a parallel plane to the hook.

The shearable means is spaced from the attachment point of the safety line and remote from the hook and is preferably such that under normal usage will remain intact or in place. lo a preferred embodiment the shearable means comprises a shear pin on eath side of the safety line and between opposite sides of the slot in the body of the device. In an alternative preferred embodiment, the shearable means may comprise a ring or the like surrounding the safety line and held in a groove of the.body of the device. When We device is subjected to a substantial sideways force due, for example, to the fall of a user of the device, _ _ whereby the safety line is pulled laterally of the device, the shearable means will shear to allow the safety line to pivot about its attachment point, which is closer to the hook. That reduces the moment exerted on the device and reduces the risk of it being compromised.

Entry to and exit from the hook is preferably guarded. A spring-biased keeper or gate may be provided to close the hook The keeper is preferably pivotally mounted to the body of the device. The keeper is preferably arranged to be pushed inwards to open access to the hook and is preferably urged against the end of the hook to dose the hook. Furthermore, it is preferable to have a

locking means to prevent inadvertent movement of the keeper to open access to the hook The locking means is preferably a spring-biased lever that normally abuts against the keeper to prevent inwards movement thereof but can be moved about a pivot to release the keeper for movement thereof This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: figure 1 shows a safety line connector according to the invention; Figure 2 is a side view of the connector of Figure 1; Figure 3 shows the safety line attachment of the device of Figure 1; Figure 4 shows detail of Me device of Figure 1; Figures and 6 show operation of We lock lever of the device of Figure 1; Figures 7, 8 and 9 shows stages in the attachment of the device to a pylon bolt head; Figures 10 and 11 show the effect of a fall on the device of Figure 1.

Referring to the accompanying drawings, a device 10 for attaching a safety line to a bolt head 11 or the like extending from a structure, such as an electricity pylon 12 comprises a body 14, which at one end is in the form of a hook 16 and at the other end (18) is slotted transversely to the hook to provide a location for attachment of a safety line 20. The hook 16 is used to attach the device 10 to the bolt head 11 (see Figures 7 to 9). The safety line 20 is looped over

a collar 21 on a load bar 22 across the slot 18 and its free end stitched (24) to the line to form a loop 24.

At the free ends 26 of the slot 18 on opposite sides of the safety line 20 are shear pins 28.

Pivotally mounted on the body 14 is a spring-loaded keeper 30. The keeper is arranged to abut the free end of Me hook 16 and is normally urged to do so by spring 32. On the opposite side of the body 14 a spring-loaded lock lever 34 is pivotally mounted. The lock lever 34 has a pair of pawls 36 arranged an onpocile sides Of me body At no1 Ally abut pans or fine keeper 30, whereby the keeper is maintained in a closed position, i.e. preventing anything entering or leaving the hook area. The lock lever 34 is urged into its locking position by spring 38 and has a handle 40 that can be depressed onto the body to move the pawls 36 to a position where they no longer abut the keeper 30. Ibe keeper has its edges 42 wider at 44 for the pawls 36 to abut when locking the keeper and narrower at 46 to provide space for the keeper to pass over the pawls as they are pivoted upwards when the lock lever handle 40 is depressed. The lock lever 34 is normally urged into a locking position, so that the keeper cannot be depressed to allow the device to be attached to or removed from a bolt head unless the lock lever is first depressed (see Figures and 6)

The attachment of the device 10 to a bolt head 11 of an electricity pylon 12 is shown in Figures 7, 8 and 9. Firstly, the lock lever 34 is depressed which allows the keeper 30 also to be depressed either by hand OI by bung pushed against the bolt head 11. Depression of the keeper 30 opens access to the hook 16, which then fits over the bolt head. Once the hook is fully on the bolt head, the keeper and the lock lever are released to return to their normal positions, so that the hook is closed by the keeper and the keeper is held in place by the lock lever. The hook is sized so that the device cannot be pulled off the bolt along its length, being prevented form doing so by the head of the bolt.

In normal circumstances the device 10 will be locked onto a bolt head above the user until the user has climbed past the device when it will be moved to a higher point. If the user falls so that pressure is exerted on the device, as shown in Figures 10 ard 11, due to forces on the safety line in the general direction of the arrows in those drawings, the safety line will break one or other of the shear pins 28, so that * can pivot about its attachment bar 22 to reduce the moment applied to the device against the bolt head. It is less likely in these circumstances for the integrity of the device to be compromised. In other words, Me device is less likely to be damaged to the extent that it can come away from its attachment point. Under normal conditions the safety line will not pivot

l . about its attachment bar, whim renders Me dence easier to handle and manoeuvre

Claims

1. A device for attaching a safety line to a projecting structure, the device comprising a body having a hook at one end and a pivotal attachment point 5 for a safety line, wherein the safety line is constrained against pivoting about said pivotal attachment point by shearable means remote from the hook and spaced from the attachment point, whereby shearing of the shearable means will permit said pivoting.

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2. A device according to claim 1, in which the body has a slot in its end opposite to the hook and the safety line attachment point is a bar or the like extending across the slot.

3. A device according to claim 2, in which the bar or the like is in the 15 same plane, or a parallel plane, to the hook.

4. A device according to any of the preceding claims, in which the shearable means is arranged such that under normal usage it will remain intact or in place.

5. A device according to claim 4, in which the shearable means comprises a shear pin on each side of the safety line and between opposite sides of the slot in the body of the device.

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6. A device according to claim 4, in which the shearable means comprises a ring or the like surrounding the safety line and held in a groove of the body of the device.

7. A device according to any of claims 4 to 6, in which the device is 30 arranged such that when subjected to a substantial sideways force, due, for example, to the fall of a user of the device, whereby the safety line is pulled laterally of the device, the shearable means will shear to allow the safety line to pivot about its attachment point, which is closer to the hook.

8. A device according to any of the preceding claims, in which entry to and exit from the hook is guarded.

9. A device according to claim 8, in which a spring biased keeper or gate 5 is provided to close the hook.

10. A device according to claim 9, in which the keeper is pivotally mounted to the body of the device.

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11. A device according to claims 9 or 10, in which the keeper is arranged to be pushed inwards to open access to the hook.

12. A device according to any of claims 9 to 11, in which the keeper is arranged to be urged against the end of the hook to close the hook.

13. A device according to any of claims 9 to 12, in which a locking means is provided to prevent inadvertent movement of the keeper to open access to the hook.

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14. A device according to claim 13, in which the locking means is in the form of a spring-biased lever that nomnally abuts against the keeper to prevent inwards movement thereof but can be moved about a pivot to release the keeper for movement thereof.

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15. A device for attaching a safety line to a projecting structure, the device being substantially as hereinbefore described and with reference to the accompanying drawings.

16. Any novel subject matter or combination including novel subject matter 30 disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.