GB2460624A

GB2460624A - A safety platform for a manhole

Info

Publication number: GB2460624A
Application number: GB0808054A
Authority: GB
Inventors: Graham Nicholson
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-02
Filing date: 2008-05-02
Publication date: 2009-12-09
Also published as: GB0808054D0

Abstract

The invention relates to a safety device 2 for a manhole assembly 4. The safety device 2 comprises a platform 10 adapted to lay adjacent a part of the manhole assembly 4, and a restraining means 12. The platform 10 is adapted to support a person during the construction of the manhole assembly 4, and the restraining means 12 is adapted to restrain the person to the safety device 2. Angle irons and lugs 14 are preferably provided on the underside of the platform 10 to help guide the platform 10 into a working position on top of the manhole ring 6. A later embodiment relates to a method of constructing a manhole assembly.

Description

A Safety Device The invention relates to a safety device. Particularly, but not exclusively, the invention relates to a safety device for a manhole assembly. The invention further relates to a method of constructing a manhole assembly.

A manhole assembly, or manhole, is a mamrade hole through which a person can gain access to an underground structure, for example, a sewer. The manhole assembly generally comprises a number of manhole rings which are layered on top of each other from the sewer to ground level. A concrete lid or slab closes over the top of the manhole to help prevent a person from accidentally falling into the manhole. An opening is provided in the lid, plugged by a plug comprising a cast iron manhole and frame, to allow for inspection of the manhole. The plug is generally the only part of the manhole assembly which is visible at ground level.

The construction of a manhole assembly is particularly hazardous. This is due to the depth of the assembly, which can be many metres, and the risk that a worker can easily fall down into the manhole. In particular, during construction, it is common practice for the lid to be placed on top of a manhole ring, and a construction worker to balance on the lid whilst working. At present, there is no known mechanism in place to prevent the construction worker from accidentally falling from the lid.

It is an object of the invention to provide a safety device for a manhole assembly which aims to overcome the aforementioned problems.

According to an aspect of the present invention, there is provided a safety device for a manhole assembly, the safety device comprising a platform adapted to lay adjacent a part of the manhole assembly, and a restraining means, wherein the platform is adapted to support a person during the construction of the manhole assembly, and the restraining means is adapted to restrain the person to the safety device, The term restrain could mean preventing a person from passing or moving over or falling past the manhole assembly, or a manhole ring.

Preferably, the platform has substantially the same shape in plan as a manhole ring. Preferably, the platform is circular in plan. Preferably, the platform has a diameter which is greater than or equal to the diameter of a manhole ring, preferably being adapted to lay adjacent the manhole ring. Preferably, the platform has a diameter less than the diameter of a manhole shutter of the manhole assembly.

Preferably, the platform is a manhole lid. Preferably, at least one angle iron and/or lug is provided on the safety device. Preferably, the or each angle iron and lug is provided on the platform, preferably an underside of the platform. The or each angle iron and/or lug prevents the safety device, preferably the platform, from moving out of a desired position on the manhole assembly. Provision of the angle irons and lugs, preferably set at 25mm less than the internal diameter of the manhole ring, ensure correct positioning of the platform.

Preferably, the restraining means is a barrier.

Preferably, the barrier comprises attaching means for attaching a lifting device or safety harness to the platform. Preferably, the attaching means comprise lifting eyes, preferably precast into the platform.

Preferably, three lifting eyes are provided, preferably located around the periphery of the platform, preferably in an equidistantly spaced arrangement. Preferably, the attaching means are removably fixed to the manhole assembly.

Advantageously, a chain can be threaded through the lifting eyes to attach to a safety harness of a worker to prevent him from falling off the platform. Further, when three eyes are provided, chains can be linked through the lifting eyes to meet at a central point, to enable the safety device to be lifted off the manhole assembly in a balanced manner.

Preferably, the barrier comprises at least one post and preferably at least one rail. Preferably, at least one rail is provided between two posts. Preferably, the or each post is removably fixed to the platform. Preferably, a plurality of posts is provided, preferably, eight posts are provided on the platform. Preferably, the posts are arranged around the periphery of the platform, preferably equidistantly spaced apart, preferably in an octagonal configuration. Preferably, two rails are provided between pairs of posts. Preferably, the or each rail comprises a substantially rigid joint. The or each rail may comprise a chain. The rail may comprise a plurality of joints or chains.

Preferably, a locking mechanism is provided on the safety device. Preferably, the locking mechanism is adapted to lock and preferably, release the or each rail. The arrangement enables a person to open or close the barrier.

Provision of a platform comprising a barrier helps to ensure a safe working environment for a worker during the construction of a manhole assembly. The barrier helps to prevent the worker from accidentally falling off the platform.

The invention further relates to a method of constructing a manhole assembly comprising the steps of: 1) positioning a manhole ring in a desired location in the ground, 2) locating a safety device as hereinbefore described adjacent the manhole ring, 3) carrying out construction of said assembly, a construction worker working from the platform of the safety device.

Preferably, the method comprises a step (i) of placing a manhole shutter around the manhole ring. Preferably, step (i) takes place after step (1) Preferably, concrete is poured between the manhole ring and the manhole shutter.

Preferably, the safety device is removably fixed to the manhole assembly.

Preferably, the method comprises a step (4) in which the safety device is removed from the manhole assembly when construction is completed.

In a further aspect, the invention provides a manhole assembly comprising a removably fixed safety device as hereinbefore described. Preferably, the safety device is removably fixed to a manhole ring, preferably a manhole lid or slab. Preferably, attaching means are provided on the manhole assembly, preferably the manhole ring, preferably the manhole lid or slab. Preferably, the attaching means comprise bolts which are preferably precast into the manhole ring, or preferably the manhole lid or slab. Preferably, sockets are provided in the manhole assembly, preferably the manhole ring, or preferably the manhole ring or slab, the sockets being adapted to receive the or each post. Preferably, the posts fit into the sockets in a push fit manner.

Advantageously, in this arrangement, the safety device which can be removably fixed to the manhole assembly. In so doing, the safety device can be fixed and readily removed from the manhole assembly at any desired point in the construction of said assembly.

Advantageously, the provision of a manhole lid incorporating a removable safety device allows the lid to be used as both a safety platform and a manhole lid or slab when the manhole assembly has been constructed.

In so doing, when the manhole assembly has been completed, the safety device can be simply removed from the lid to be re-used in the construction of further manholes.

Preferably, the manhole ring is a precast concrete manhole ring.

Preferably, the manhole lid or slab is precast concrete.

All of the features described herein may be combined with any of the above aspects, in any combination, An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings: Figure 1 shows a schematic perspective view of a safety device according to the invention; Figure 2 shows a schematic top view of a safety device according to the invention; Figure 3 shows a schematic front view of a safety device according to the invention; Figure 4 shows a schematic front view of a safety device according to the invention; Figure 5 shows a schematic top view of a safety device according to the invention; Figure 6 shows a schematic top view of the invention of figure 5; Figure 7 shows a schematic front view of a safety device according to the invention; Figure 8 shows a schematic top view of a safety device of Figure 7; Figure 9 shows a schematic top view of a safety device according to the invention; Figure 10 shows a schematic top view of a safety device according to the invention; and Figure 11 shows a schematic perspective view of a safety device according to the invention.

Figure 1 shows a safety device 2 according to the invention. The safety device 2 is mounted on a manhole assembly 4. The manhole assembly 4 comprises a number of manhole rings 6 which are assembled in a layered configuration. The manhole rings 6 are surrounded by a manhole shutter 8.

The safety device 2 comprises a platform 10 and restraining means 12. The platform 10 is circular in top view and is dimensioned to cover the top of the manhole ring 6. Angle irons and lugs 14 are provided on the underside of the platform 10, located approximately 25mm in from the internal diameter of the manhole ring 6, to help guide the platform 10 into a working position on the manhole ring 6. The angle irons and lugs 14 further help to prevent the platform 10 from sliding out of the working position.

The restraining means 12 comprises a plurality of posts 16. The posts 16 are spaced around the circumference of the platform 10. The posts 16 may be removably fixed to the platform 10 by attaching means, for example, bolting means. The posts 16 may be fixed to the platform 10 by push fitting into sockets located on the platform 10. As shown in the figures, eight posts 16 are provided being equidistantly spaced apart in an octagonal configuration.

However, it will be understood by the reader that any number of posts 16, in any suitable configuration, may be provided on the platform 10.

The posts 16 are linked to each other by rails 18. Two rails 18 are provided between each pair of posts 16, as shown in Figure 1. However, it will be understood that any suitable number of rails may be provided. Further, the posts 16 may be interconnected by solid fences.

The rails 18 may comprise rigid joints 20 or chains 24.

The rails 18 shown in Figures 1 to 3 comprise rigid joints 20. A locking mechanism 22 is provided on at least one post 16 to allow the user to open and close the rail 18 to allow access to the platform 10.

Figures 4 to 9 show alternative configurations of the safety device 2.

The safety device 102 in Figure 4 comprises a platform 110 and a restraining means 112. Posts 116 are provided around the platform 110 in the same configuration to that shown in Figures 1 to 3. In the arrangement of Figure 4, the rails 118 located at the front of the restraining means 116, comprise chains 124. Two chains 124 are shown.

The chains 124 lock into a locking mechanism 122 to allow access in and out of the platform 110.

In the alternative configuration of Figures 5 and 6, the safety device 202 has rails 218 comprising rigid joints 220 and a chain 224. The chain 224 is provided to the rear of the safety device 202. In this configuration, the construction worker can enter or exit the platform 210 by unlatching the chain 224.

Figures 7 and 8 show a further alternative configuration of a safety device 302. In this configuration, a chain 324 is provided at the front part of said device 302, and can be opened or closed by a latching mechanism 322.

Figure 9 shows a further alternative configuration of a safety device 402 wherein each rail 418 comprises a chain 424.

Figure 10 shows a lifting mechanism 26 for use with any one of the aforementioned safety devices. The lifting mechanism 26 comprises lifting eyes 28 and lifting chains 30. Three lifting eyes 28 are shown in Figure 10, located equidistantly around the circumference of the platform 10.

Each lifting eye 28 is fixedly secured to the platform, for example, the lifting eyes 28 may be concreted into a fixed position. The lifting chains 30 are threaded through each of the lifting eyes 28 and are brought together at a central point 32. the platform 10 is raised from the central point 32 by a lifting device, for example, a crane. Advantageously, lifting from the central point 32 ensures that the platform 10 is in a balanced configuration which allows safe removal from the top of the manhole ring 6.

Figure 11 shows an alternative embodiment of the invention in which the safety device 502 is an integral part of the manhole ring 516. In this configuration, the posts 516 are removably fixed to the platform 510. In so doing, when the manhole ring 516 is at ground level, the construction worker can simply remove the posts 516 and thus the safety device 502. The platform 510 thus becomes a manhole lid. A manhole cover and frame 534 may then be fitted into an opening 536 on the platform 510, in a conventional manner.

Advantageously, the safety device provides a means of helping to prevent a construction worker from falling from the manhole assembly while working.

It is also envisaged that, in a simple form, the safety device may comprise a platform having a number of lifting eyes. A harness may be fitted through said eyes to secure the worker to the platform. The lifting eyes may be removably fixed to the manhole assembly.

The safety device is designed for use whilst constructing precast concrete manholes to form a safe working platform for operatives. The safety device provides a mechanism to prevent operatives from falling from a manhole whilst undertaking construction work. The safety device is therefore provides an aid to ensure a safe working environment.

Advantageously, provision of a locking mechanism allows access and egress to the platform. The locking mechanism may be opened and closed by a clip chain system. The joints may comprise tubular steel hand rails to help protect the operative from falling whilst the concrete surround is being placed in the surrounding manhole shutter.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification

(including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s) . The invention extends to any novel one, or any novel combination, of the features

disclosed in this specification (including any

accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS1. A safety device for a manhole assembly, the safety device comprising a platform adapted to lay adjacent a part of the manhole assembly, and a restraining means, wherein the platform is adapted to support a person during the construction of the manhole assembly, and the restraining means is adapted to restrain the person to the safety device.
2. A safety device as claimed in claim 1, wherein the platform has substantially the same shape in plan as a manhole ring.
3. A safety device as claimed in claim 1 or 2, wherein the platform has a diameter which is greater than or equal to the diameter of a manhole ring, being adapted to lay adjacent the manhole ring. * S. * . *
4. A safety device as claimed in any one of the preceding claims, wherein the platform has a diameter less than the * diameter of a manhole shutter of the manhole assembly. S...S S..S
5. A safety device as claimed in any one of the preceding :.. 25 claims, wherein the platform is a manhole lid.
6. A safety device as claimed in any one of the preceding claims, wherein at least one angle iron and/or lug is provided on the safety device.
7. A safety device as claimed in claim 6, wherein the or each angle iron and lug is provided on the platform.
8. A safety device as claimed in any one of the preceding claims, wherein the restraining means is a barrier.
9. A safety device as claimed in claim 8, wherein the barrier comprises attaching means for attaching a lifting device or safety harness to the platform.
10. A safety device as claimed in claim 9, wherein the attaching means comprise lifting eyes, precast into the platform.
11. A safety device as claimed in claim 10, wherein three lifting eyes are provided, located around the periphery of the platform, in an equidistantly spaced arrangement.
12. A safety device as claimed in any one of claims 8 to 11, wherein the barrier comprises at least one post and at least one rail. * S. * * *
13. A safety device as claimed in claim 12 wherein, the or * 55.each post is removably fixed to the platform. * *5 * S S **
14. A safety device as claimed in claim 12 or 13, wherein a plurality of posts is provided, the posts being arranged around the periphery of the platform, equidistantly spaced * ** apart.
15. A safety device as claimed in claim 14, wherein the posts are arranged in an octagonal configuration.
16. A safety device as claimed in any one of the preceding claims, wherein a locking mechanism is provided on the safety device.
17. A method of constructing a manhole assembly comprising the steps of: 1) positioning a manhole ring in a desired location in the ground, 2) locating a safety device as hereinbef ore described adjacent the manhole ring, 3) carrying out construction of said assembly, a construction worker working from the platform of the safety device.
18. A manhole assembly comprising a removably fixed safety device as claimed in any one of the preceding claims.
19. A safety device as substantially as hereinbefore described with reference to any one of the accompanying drawings. * ** * * * * ** * *** * * *... * ** * * * * ***S * S. * S * S..SS S * S SS SS