GB2468847A - Construction site safety device - Google Patents

Abstract

A safety device 10 comprises a base portion 12 which includes a first ground engaging face 14 and a projection 22 extends from the first ground engaging face of the base portion. The safety device is used to cover a floor level hole in a construction site, e.g. a manhole prior to the frame and cover being installed, or pipe or duct aperture. In a first configuration use, the base portion overlies the hole to be covered, and the projection 22 is positioned within the hole. The base portion is further characterised by a second ground engaging face 16 and wherein the projection 22 includes means 22a for receiving and retaining a pole. The safety device may serve a second purpose when in a second configuration, i.e. when used the other way up, where the second face of the base engages the ground and the projection extending from the base can receive and retain a pole for warning purposes, such as overhead cabling indicating "goal posts".

Description

Safety Device This invention relates to a safety device for use on a construction site.

Safety is an extremely important consideration in the construction industry. The present inventor has identified a number of areas of common construction practice in which either safety could be improved or current practices have other drawbacks.

Manholes are well known constructional elements which have an upper aperture permitting access to the interior of underground systems such as sewer systems. In use, the manhole aperture is covered by a cover and frame arrangement. However, during installation of a manhole cover it is not always possible to fix the cover and frame in position straightaway. In these circumstances, the aperture of the manhole is a hazard, since people might fall into the aperture, potentially causing serious injury. If an injury occurs to a member of the public, then the site manager may be prosecuted for not securing the site properly, even if the member of the public illegally broke into the site.

Children are quite regularly injured playing on building sites.

Typically, a piece of plywood or light material has been simply placed over the hole without fixing the covering material in place. Therefore, the covering material can be moved very easily and, furthermore, there is a risk that heavy machinery may run over the material thereby breaking it. Furthermore, since this procedure is done in an ad hoc manner, there is a risk that the material might be taken away and used for another purpose. Whilst it is possible to fix the covering material in place by way of suitable fixing elements such as plugs and screws, in practice the necessary items may not be available, and in any event the manpower or even willingness to perform this procedure may be lacking. Pallets or Heras fence panels have also been used for the same purpose, but these items do not offer any more protection. Another possible option is to temporarily position the frame and cover over the hole. However, this is not a very satisfactory option, even assuming that the frame and cover is available on site. The frame and covers are too heavy to be lifted by one person, and suitable equipment, such as a dumper is required. In any event, at least two persons are required to position the frame and cover over the hole, and the weight of the item carries a risk of injury, especially to fingers. The covers are difficult to lift without removing the covers from the frame, and if they are accidentally moved after placement on the manhole, it is difficult to correctly reposition. Furthermore, it has been known for covers to be dropped into the manhole, thereby causing extensive damage. It is noted that in the UK it is not recommended by the Health & Safety Executive for a person to lift more than 25kg at one time, and clearly this has a bearing on the practicality of the solution to the problem of open manhole apertures.

Similar hazards are associated with other exposed openings such as ducts for air conditioning, cables and the like, and pipes such as heating and ventilation pipes.

Another safety consideration concerns the placement of warning signage in the vicinity of potential hazards. It is well known to provide so called "goal posts", which are posts commonly used on construction sites to denote the presence of overhead cables or other structures. Typically, the poles are painted red and white, and are, for example, positioned on each side of a road or track which approaches the hazard. The goal posts serve as a warning to ensure that, for example, lorry tipper bodies are fully in the down position and that the buckets of excavators are lowered. Accidents have occurred on sites where tippers or machines have come in contact with overhead cables, and drivers have been badly burnt or even killed as a result of these accidents.

The goal posts are disposed in a base, which is commonly a concrete filled oil drum. Such bases weigh nearly 500kg, and cannot be moved without a forklift or other suitable heavy mechanical device. These bases are inherently unstable owing to the shape of the drum, and in fact it is not difficult to tip a base over. This is very hazardous, particularly since the oil drum can then very easily roll in an uncontrolled manner. There are further disadvantages associated with goal post bases. For example, it is not always possible to obtain an empty oil drum in the first place, and the removal of the drum top can be time consuming and difficult. It has been known for the use of a disk cutter to remove the top of an oil drum to cause an explosion. In any event, when this method is used, a very sharp edge is left around the top of the drum which creates another hazard.

Since the concrete must be prepared, poured and then set, it is not possible to use the base until the day after the day of manufacture. A further problem is that any accident involving a collision of a vehicle with the goal post base can result in a great deal of damage and, possibly, other serious consequences. A further problem still is the cost of these goal post bases, which is typically around �150 per unit. Further costs are associated with moving a goal post to its required position. Furtherstill, it is not convenient to reuse a goal post base, since transportation is time consuming and expensive, and therefore bases are typically only used once and then disposed of.

The present invention, in at least some of its embodiments, addresses some or all of the above described problems. In particular, a single device is provided which addresses at least some of the problems associated with manhole apertures and other large floor level apertures.

According to a first aspect of the invention there is provided a safety device for concealing a large floor level aperture in a construction site including: a base portion sized so as to be able to completely overlay the aperture and having a first ground engaging face; and a projection extending from the first ground engaging face of the base portion which is sized and disposed so that, in use, the projection is positionable in the aperture whilst the base portion completely overlays the aperture.

The device is convenient to use, and to reuse, and is easily transportable.

A "large floor level aperture" is understood to refer to apertures of a size greater than 100mm, preferably greater than 150 mm, which includes, but is not limited to, a manhole cover, a duct or a pipe opening. The term "floor level" is understood to include within its scope ground level and the level of any floor in a building.

The projection may be of dimensions greater than 150 mm, preferably greater than 300 mm, most preferably greater than 500 mm. Typically the projection is of dimensions less than 900 mm. In a particularly preferred embodiment, the projection is of dimensions about 650 mm. The base portion may be of dimensions greater than 300 mm, preferably greater than 500 mm, most preferably greater than 750 mm. Typically, the base portion is of dimensions less than 1200 mm. In a particularly preferred embodiment, the base portion is of dimensions about 900 mm.

It is understood that the term "dimensions" here refers to the major axis or axes relating to the feature in question. Thus, the dimension may be a diameter of a circle, or a width or length of a rectangle or square.

Preferably, the projection is in the form of a cylinder, more preferably a disc. A disc shape is particularly suitable for extending into many types of manhole. However, other shapes which are suitable for projecting into a desired floor aperture might be contemplated, such as a cuboid shape which is either substantially square or rectangular in plan view.

Preferably, the base portion is substantially square or rectangular in plan view. It is in principle possible to provide base portions having different shapes, and indeed this may be desirable depending on the shape of the large floor level aperture which it is intended to cover. For example, a base portion which is substantially circular in plan view might be utilised.

Typically, the depth of the projection and/or base portion are each less than 100 mm, more typically in the range 30 to 80 mm.

Preferably, the projection is positioned generally central of the first ground engaging face.

The second device may be hollow, e.g., the base portion projection may define an enclosed internal cavity.

In one embodiment, the base portion has a second ground engaging face and the projection extending from the first face of the base portion includes means for receiving and retaining a pole; in which the projection is positioned so that the device can adopt a first configuration in which the base portion engages the ground using the first face and completely overlays the aperture with the projection extending into said aperture, and a second configuration in which the base portion engages the ground using the second face with the projection upstanding from the base so as to be able to receive and retain a pole for warning purposes.

In this way, a single device is provided which, when used one way up, serves as a convenient cover for an exposed aperture and which, when used the other way up, serves as a convenient base for a "goal post".

Preferably, the first face has a peripheral rim upstanding therefrom. It will be appreciated by the skilled reader that, in such embodiments, the adoption of the first configuration by the device involves the ground being engaged by the peripheral rim rather than the first face per se. The terms "engages the ground using the first face" and "engages the ground using the second face" are intended to encompass both direct engagement of the ground by a face and also "indirect" engagement of the ground through an intermediate structure such as a rim.

The second face may be provided with a rim upstanding therefrom, although it is preferred that the second face does not posses a rim, but rather engages the ground directly.

Preferably, the means for receiving and retaining the pole includes a tubular member.

Advantageously, the device further includes one or more ribs disposed on the first face for strengthening purposes. Advantageously, the one or more ribs extend from the periphery of the first face to the projection.

The base portion may have one or more bores formed therein for receiving and retaining the shaft of a warning pole and/or the legs of a signage carrying frame. The one or more bore may have an opening formed in or disposed above the second face so that, when the device has adopted the first configuration, the shaft of a warning pole and/or the legs of a signage carrying frame can be received and retained in the base portion. In this way, the location of the manhole can be signalled for warning purposes.

Advantageously, the one or more bores have an opening formed in the first face or disposed above the first face.

Preferably, the one or more bores extend between the first face and the second face. Advantageously, each bore also extends in a tubular member which is upstanding from the first face.

The device may be formed from any suitable material, although it is preferred that a plastics material is utilised. In this way, a tough device can be produced which can withstand being run over by a item of heavy machinery.

Furthermore, it is possible to produce a device for practical utility which weighs under 50kg, and therefore can be safely transported by two persons. The device may be manufactured conveniently using rotational moulding.

Since the base portion is generally low height, the device has a low centre of gravity and is relatively stable, even when it is used to house a "goal post".

Typically, in use the device is simply positioned over an aperture, and it is not necessary to fix the device in place. In these embodiments, the width of the projection is less than the width of the aperture. For example, the width of a manhole aperture is typically 675mm, and the width of the projection may be appropriately sized to fit there within. Typically, the width of the projection is greater than 500mm, preferably greater than 600mm. In other embodiments it may be possible to provide devices having a structure depending from the first face which is sized to extend into the aperture and form a friction fit therewith.

The projection may be suitably sized to form a friction fit with the aperture.

According to a second aspect of the invention there is provided a method of concealing a large floor level aperture in a construction site including the steps of: providing a safety device according to the first aspect of the invention; and overlaying the aperture with the safety device so that the projection is positioned in the aperture and the base portion completely overlays the aperture.

The large floor level aperture may be a manhole, a duct or a pipe opening. The floor level aperture may be formed in the ground on a construction site, or in any floor of a building or structure, such as a multi-storey building.

Whilst the invention has been described above, it extends to any inventive combination or sub-combination of the features set out above or in the

following description or drawings or claims.

Embodiments of devices in accordance with the invention will now be described with reference to the accompanying drawings, in which:-Figure 1 is a plan view of a device of the invention; Figure 2 is side view of a device of the invention; Figure 3 is a cross-sectional side view of the device of the invention; Figure 4 is a perspective view of a second device of the invention in a second configuration; Figure 5 is a side view of the second device of the invention in a second configuration; Figure 6 is a plan view of the second device of the invention in a first configuration; and Figure 7 is a plan view of the second device of the invention in a second configuration.

Figures 1 to 3 show a first embodiment of a safety device, depicted generally at 40, of the invention. The device 40 comprises a base portion 42 in the general form of a thin cuboid having first 44 and second 46 planar main faces. Upstanding from the first face 44 is a projection 48 disposed centrally thereon. The projection 48 is in the form of a thin cylinder or disc. The device can be conveniently formed from a plastics material by rotational moulding.

As shown in Figure 3, the device may be hollow, having an interior cavity 50. If desired, internal ribs 52 can be provided for strengthening purposes.

The device 40 acts as a cover for an aperture in a construction site such as a manhole. In use, the device 40 is positioned over the aperture (not shown) so that the projection 48 extends into the aperture, with the first face 44 engaging the floor. In a representative example which is suitable for use with commonly employed manholes, the base portion 42 is, in plan view, a square of side length 900 mm, the disc projection 48 is of 650 mm diameter, and the depths of both the base portion 42 and projection 48 are 50 mm.

Figures 4 to 7 show various views of a dual purpose safety device, depicted generally at 10, of the invention. The device 10 comprises a base portion 12 in the general form of a tray having first 14 and second 16 planar main faces. A peripheral rim 18 is upstanding from the first face 14. The peripheral rim 18 has a plurality of apertures 20 disposed therein which allow the device 10 to be conveniently picked up.

Upstanding from the first face 14 is a projection structure 22 disposed centrally thereon. The projection structure 22 comprises a cylindrical tubular member 22a having a cylindrical bore, a plurality of buttresses 22b each of which is disposed longitudinally along the tubular member 22a, and an outer ring 22c which is in contact with the end of each buttress 22b distal to the tubular member 22a. The tubular member 22a is sized so as to be able to receive and retain a "goal post" pole of the type commonly used in the construction industry to warn of hazards such as overhead cabling. The structure of the projection 22 provides structural strength enabling the goal post to be conveniently retained.

However, other suitable structures would rarely suggest themselves to the skilled person.

The base portion 12 is substantially square in plan view (see Figures 6 and 7). Each corner of the base portion 12 is provided with a tubular member 24 which is upstanding from the first face 14 and is disposed slightly inwardly of the rim 18. Each tubular member 24a has a central bore which continues through the base portion to provide an aperture in the second face portion 16 (Figure 7).

Ribs 28 extend from corner of the base portion 12 to the nearest tubular member 22a and then run from the tubular member 22a to the outer ring 22c of the projection structure 22. The ribs 28 provide enhanced structural strength.

The device 10 is primarily intended to perform two functions. Firstly, the device 10 can act as a cover for a manhole aperture when used in a first configuration as shown in Figure 6. Secondly, the device 10 can act as the base for a "goal post" when used in a second configuration shown in Figures 4, 5 and 7. In the first configuration shown in Figure 6, the device 10 is positioned over the manhole aperture (not shown) of a manhole 30 which has been positioned in a suitable excavation. The device 10 is positioned with the second face 16 upward. The device 10 contacts the upper surface of the manhole (and depending on the dimensions the upper surface of the manhole, the device 10 possibly contacts the ground as well) by way of the rim 18, tubular members 24 and ribs 18, with the projection structure 22 extending downwardly into the manhole aperture. The projection structure 22 is sized so as to be smaller than the aperture of the manhole 30, i.e., the projection structure 22 does not provide a tight fit against the aperture of the manhole. However, the projection 22 does perform some degree of a locking function, since it will prevent horizontal movement of the device 10 by more than a relatively small amount.

In the second configuration shown in Figures 4, 5 and 7, the device 10 is positioned "upside down" with respect to the first configuration, with the base portion 12 resting on the second face 16. In the second configuration, the projection structure 22 projects upwardly, and is used to receive a pole, e.g. a "goal post", which is used to signal the presence of a hazard such as overhead cables. The device 10 provides a stable platform for a pole with a low centre of gravity. The device 10, if desired, can be weighed down with ballast such as sandbags, concrete blocks etc. The rim 18 in conjunction with the ribs 18 provides a number of recesses in which such ballast can be conveniently positioned. Further warning signs can be positioned in the apertures 24a of the tubular members 24 if desired. These further warnings might be further poles, but preferably are the legs of frames which are used to carry appropriate warning signage. The separation between adjacent bores 24a can be of a dimension so that industry standard frames can be positioned therein. For example, a separation of 1.1 metres can be provided enabling standard UK sign holder frames to be disposed in the device of the invention.

The dimensions of the device 10 are selected so that when used in the first configuration, the base portion 12 totally covers the desired manhole aperture. Typically, the embodiment shown in Figures 3 to 7 is of greater than 1 metre width, typically around 1.2 metre width. The device is conveniently positioned over and removed from a manhole aperture. The low profile of the device and the action of the projection as a "plug" have the result that the device is not easily moved unintentionally once in position.

The device can be manufactured from any suitable material, although a tough plastics material is preferred. In this way, strong devices can be conveniently produced which will not rot or easily break and, which can withstand being run over by an item of heavy machinery. A further advantage is that the devices can be produced which weigh under 50kg, and therefore are easily and legally transportable by two persons.

Claims (14)

1. Claims 1. A safety device for concealing a large floor level aperture in a construction site including: a base portion sized so as to be able to completely overlay the aperture and having a first ground engaging face; and a projection extending from the first ground engaging face of the base portion which is sized and disposed so that, in use, the projection is positionable in the aperture whilst the base portion completely overlays the aperture.
2. 2. A safety device according to claim 1 in which the projection is of dimensions greater than 150 mm, preferably greater than 300 mm, most preferably greater than 500 mm.
3. 3. A safety device according to claim 1 or claim 2 in which the base portion is of dimension greater than 300 mm, preferably greater than 500 mm, most preferably greater than 750 mm.
4. 4. A safety device according to any previous claim in which the projection is in the form of a cylinder, preferably a disc.
5. 5. A safety device according to any previous claim in which the base portion substantially square or rectangular in plan view.
6. 6. A safety device according to any previous claim in which the projection is positioned generally central of the first ground engaging face.
7. 7. A safety device according to any previous claim which is hollow.
8. 8. A safety device according to any previous claim formed from a plastics material.
9. 9. A safety device according to any previous claim in which: the base portion has a second ground engaging face; and the projection includes means for receiving and retaining a pole; in which the projection is positioned so that the device can adopt a first configuration which the base portion engages the ground using the first face and completely overlays the aperture with the projection extending into said aperture, and a second configuration in which the base portion engages the ground using the second face with the projection upstanding from the base so as to be able to receive and retain a pole for warning purposes.
10. 10. A dual purpose safety device according to claim 9 in which the means for receiving and retaining the pole includes a tubular member.
11. 11. A method of concealing a large floor level aperture in a construction site including the steps of: providing a safety device according to any one of claims ito 10; and overlaying the aperture with the safety device so that the projection is positioned in the aperture and the base portion completely overlays the aperture.
12. 12. A method according to claim Ii in which the large floor level aperture is a manhole.
13. 13. A method according to claim Ii in which the large floor level aperture is a duct or a pipe opening.
14. 14. A safety device or method substantially as described herein with reference to the accompanying drawings.