GB2357542A

GB2357542A - Scaffold safety device comprising a chain to which can be attached a harness

Info

Publication number: GB2357542A
Application number: GB9930622A
Authority: GB
Inventors: David Jack Isbell
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-12-24
Filing date: 1999-12-24
Publication date: 2001-06-27
Anticipated expiration: 2019-12-24
Also published as: GB9930622D0; GB2357542B

Abstract

A method of protecting a scaffolder by clamping a safety chain (22) to diagonally opposed vertical poles (12b, 12d) of a scaffold tower (10). A lanyard of a safety harness worn by the scaffolder is attached to the chain (22) by a ring slidable along the chain (22). The couplers (30) that clamp the chain (22) to the vertical poles (12a-d) may be loosened whilst still surrounding the poles (12a-d), so that the chain (22) can be repositioned without disengagement from the poles (12a-d). The chain (22) can be adjustable for length (fig 2, not shown) and positioned above head height of the scaffolder.

Description

2357542 Scaffolding Equipment

Field of the invention

The present invention relates to scaffolding equipment and in particular to the safety of scaffolders erecting and dismantling scaffolding towers.

Background of the invention

Scaffolding towers, once erected, enable workmen to work safely on the outside of buildings but their erection and dismantling itself presents a danger to the scaffolders performing the task as they are not themselves offered adequate protection by the partly erected or dismantled tower.

Scaffolding towers are commonly of rectangular or square section in plan view and are made up of several levels that are vertically spaced approximately two metres apart. Each tower has upright poles at the corners of the rectangle and these are interconnected at each level by four horizontal scaffold tubes extending along the outer sides of the tower. Two tubes or ledgers are first clamped along the longer sides of the tower then shorter tubes or transoms are clamped along the shorter sides of the tower. Additional transoms may also be fixed at regular intervals to the ledgers if the tower is wide. Further tubes or braces are clamped diagonally to the upright tubes of the tower for structural rigidity.

Scaffold boards are lashed to the transoms to form a floor at each level. For safety, vertical toe boards are lashed to the upright to form a skirting around the floor at each level and further horizontal tubes are secured to the vertical tubes to act as a handrail for workmen using the scaffolding tower.

It is already known for scaffolders erecting and dismantling the tower to wear a harness having a lanyard that is attached to a handrail by a ring. Such an attachment severely restricts the range of movement and it is therefore frequently necessary for the scaffolder to unclip the lanyard from one handrail and attach it to another.

A disadvantage of the prior art is that while moving the harness from one tube to another, the scaffolder is unprotected. Even more serious is the fact that the safety harness is so restricting and inconvenient to use that it is often not worn at all.

Object of the invention The present invention seeks to make the wearing of a safety harness less restricting on movement and to allow the attachment point of the harness to be moved simply and with less danger to the scaffolder.

Summary of the invention

According to a first aspect of the present invention, there is provided a method of protecting a scaffolder erecting or dismantling a scaffolding tower that comprises clamping a safety chain to diagonally opposed vertical poles of the partly erected or dismantled scaffolding tower and attaching the lanyard of a safety harness worn by the scaffolder to the safety chain by means of a ring slidable along the length of the chain. Such a safety chain is easy to fit to the scaffolding tower and in use it does not restrict the movement of the scaffolder wearing the harness.

Preferably, the safety chain is positioned above the head height of the scaffolder wearing the harness. If the lanyard of the harness is adjusted in length so as to be taught when the operator is standing at the opposite corners of the scaffolding tower from those to which the safety chain is clamped, then the safety harness will not restrict movement in any way while still minimising the extent to which the operator can fall in the event of an accident.

Preferably, the chain is clamped to the vertical poles of the tower by means of couplers that can be loosened while surrounding the vertical pole so that the safety chain may slide along the vertical tube to reposition it without at any time disengaging the safety chain from the vertical is poles nor lanyard of the safety harness from the safety chain.

In accordance with a second aspect of the present invention, there is provided scaffolding equipment including scaffold tubes, couplers and boards, for the erection of a scaffolding tower, in combination with a safety chain having a coupler at each end for attachment to diagonally opposed vertical scaffold poles of the towe r and a safety harness to be worn by scaffolders during the erecting and dismantling of the tower, the harness having a lanyard fitted with a ring that is attachable to and slidable along the safety chain.

Preferably, the chain is adjustable in length so that the same chain may be used in the erection and dismantling of scaffolding towers of different floor area. To this end, the coupler at one of the chain may be provided with a hook or choke over which a link of the chain may be fitted to remove slack from the chain, while leaving a span of the chain hanging loose from the choke.

Brief description of the drawings

The invention will now be described further, by way of example, with reference to the accompanying drawings, in 5 which:

Figure 1 is a schematic representation of a section of a partly erected scaffolding tower, and Figure 2 shows a safety chain in greater detail.

Detailed description of the preferred embodiment

The diagrammatic view of Figure 1 shows the top level of a partially erected scaffolding tower.

The illustrated tower 10 is square and has upright poles 12a, 12b, 12c and 12d at its corners. A platform 14 is formed at each level by means of scaffold boards 14a to 14d. The scaffold boards are lashed to transversely extending scaffold tubes 16a to 16c, referred to as transoms. The transoms are in turn clamped to longitudinally extending scaffold tubes 18a and 18b, referred to as ledgers. Various diagonal scaffold tubes, referred to as braces, are also secured to the upright poles to allow the tower to withstand shearing forces, only one such brace 20 being show in the drawing. The various scaffold tubes are clamped to one another by conventional couplers that are not shown in the drawing.

When totally erected, the tower also has vertical toe boards surrounding each platform 14 to act as a skirting for preventing items from falling off the edge of the platforms. Further horizontal scaffold tubes will be clamped to the uprights at waist level to act as hand rails.

As so far described, the tower is entirely conventional and the present invention is concerned with the safety of scaffolders engaged in the erection and dismantling of such towers. It is known for a scaffolder to wear a safety harness that is anchored to a handrail. The harness includes a belt and a lanyard that carries a split ring. The ring is slipped over a handrail to anchor thescaffolder to the existing parts of the tower while erecting or dismantling the next higher platform.

Such a method of operating is clearly safer than using no harness but it is inconvenient. If a short lanyard is used, the range that can be reached while anchored to a hand rail is limited and the scaffolder must keep changing from one handrail to another. During changes, the harness offers no protection. If the lanyard is lengthened to improve the range, then the safety is compromised since the scaffolder may fall a significant distance before his fall is checked.

In the preferred embodiment of the invention shown in the drawing, a safety chain 22 is clamped by means of couplers 30 to two diagonally opposed poles of the tower above head level and the split ring of the lanyard is slipped over this safety chain. This effectively anchors the scaffolder without restricting his movement and allows any part of the platform on which the scaffolder is standing and of the platform above to be reached with ease, without the need to unclip and reconnected the lanyard.

Once a platform has been constructed, the safety chain 22 can be slid up the upright poles by simply loosening the couplers 30 without disconnection of the lanyard from the safety chain. Even if an accident should happen during this procedure, the scaffolder will be prevented from falling off the tower as the partly loosened coupler will jam under the weight of the scaffolder.

Figure 2 shows one end of the safety chain in greater detail. The coupler 30 is formed of two U-shaped halves 30a and 30b that are pivoted to one another by means of a hinge pin 30c. A bolt 30d engaging two flanges projecting from the ends of the two halves 30 can tighten the coupler 30 about one of the upright poles 12a to 12d. To move the coupler along the pole, the bolt 30d is slackened but not removed from the flanges, thereby allowing the coupler 30 to slide to its new position.

The coupler 30 is fitted with a hook or choke 32 to allow slack to be taken out of the safety chain, thereby allowing the same chain to be used in towers of different size. A link 34 of the safety chain is pulled over the choke 32 leaving the extra slack in the chain hanging as a span 36 from the choke.

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Claims

1. A method of protecting a scaffolder erecting or dismantling a scaffolding tower that comprises clamping a safety chain to diagonally opposed vertical poles of the partly erected or dismantled scaffolding tower and attaching the lanyard of a safety harness worn by the scaffolder to the safety chain by means of a ring slidable along the length of the chain.

2. A method as claimed in claim 1, wherein the safety chain is positioned above the head height of the scaffolder wearing the harness.

3. A method as claimed in claim 1 or 2, wherein the chain is clamped to the vertical poles of the tower by means of couplers that can be loosened while surrounding the vertical pole so that the safety chain may slide along the vertical tube to reposition it without at any time disengaging the safety chain from the vertical poles nor lanyard of the safety harness from the safety chain.

4. Scaffolding equipment including scaffold tubes, couplers and boards, for the erection of a scaffolding tower, in combination with a safety chain having a coupler at each end for attachment to diagonally opposed vertical scaffold poles of the tower and a safety harness to be worn by scaffolders during the erecting and dismantling of the tower, the harness having a lanyard fitted with a ring that is attachable to and slidable along the safety chain.

5. Scaffolding equipment as claimed in claim 4, wherein the chain is adjustable in length so that the same chain may be used in the erection and dismantling of scaffolding towers of different floor area.

6. Scaffolding as claimed in claim 5, wherein the coupler at one of the chain is provided with a hook or choke over which a link of the chain may be fitted to remove slack from the chain, while leaving a span of the chain hanging loose from the choke.

7. Scaffolding equipment, constructed arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying 10 drawings.