Patent Description:
Drainage and sewer systems generally include underground pipes which, through use, are prone to becoming blocked or damaged. As pipes may run for a considerable distance underground, it is desirable to provide access to the pipes at various positions, and particularly where the pipe is joined to one or more other pipes. Such access is provided by an inspection chamber. In this application, the term "inspection chamber" is used to include manholes, access junctions and similar products which provide access to sewer or drainage systems.

To transport inspection chambers to building sites, inspection chambers are conventionally packed in cardboard boxes or wrapped in a transparent plastic film and are then placed on palettes ready for transportation. The use of cardboard boxes allows easy stacking of the inspection chambers on a palette but requires a great deal of cardboard and therefore increases the price of the inspection chamber. Packing the inspection chambers individually in cardboard boxes is also time-consuming. Transparent film is sometimes used to package the inspection chambers as this affords some protection to the inspection chamber whilst facilitating stacking of the product. However, this type of packaging is not ideal in locations where the inspection chambers are stored in their packaging in direct sunlight, as this can cause the inspection chambers to overheat and to eventually deform.

European patent application publication number <CIT> discloses an inspection/repair shaft which comprises legs of different length that extend from the bottom of a housing of the shaft. This prior art documents discloses that the legs ensure on the one hand that the shaft is arranged at an angle of <NUM> degrees in order to advance the outflow of sewage, and on the other hand that they ensure a proper nesting of stacked together housings during transport.

The present invention addresses the problems associated with transportation and storage of inspection chambers as mentioned above by providing a stacking aid for inspection chambers as well as an improved inspection chamber which permits stable stacking for transportation and storage.

According to the present invention in one aspect thereof there is provided an inspection chamber stacking aid, according to claim <NUM>.

The stacking aid may be inserted between the chambers during stacking. The stacking aid may be configured to be detachably attached to an inspection chamber. Alternatively, the stacking aid may be configured to be permanently affixed to an inspection chamber.

According to the present invention in another aspect thereof there is provided an assembly of an inspection chamber stacking aid and an inspection chamber, according to claim <NUM>.

The at least one support structure preferably comprises at least one of the group consisting of: an arcuate portion; a circular portion; an elliptical portion; a rectangular portion; a square portion; a triangular portion; a straight line portion; a discrete portion.

The at least one support structure may be formed integrally with the wall defining the interior of the chamber. Alternatively, the at least one support structure may be formed separately from and may be permanently affixed to or detachably attached to the wall defining the interior of the chamber.

Preferably the at least one support structure is for locating on, or is located on, the exterior surface of a portion of the wall defining the base of the chamber.

Where a plurality of support structures is provided, the support structures preferably comprise at least one arcuate portion. Advantageously, two arcuate portions are provided. One or more further support structures, preferably being discrete or straight line portions, may also be provided. The support structures may be connected or arranged together, or may be located separate from each other.

Alternatively, where a plurality of support structures is provided, the support structures may comprise at least three discrete or straight line portions, the support structures being arranged around the exterior surface of a portion of a wall defining the base of the chamber. The support structures may be located adjacent the openings in the wall. Such support structures may be, for example, a rod or a flange which extends from the exterior surface of the wall defining the chamber.

Advantageously, the at least one support structure is sized to fit snugly against the interior surface of the wall of the chamber around at least part of its periphery. Alternatively or additionally, the at least one support structure may be sized to fit against the exterior surface of the wall of the chamber around at least part of its periphery.

The periphery of the wall of the chamber defines the entrance to the chamber and is located at the top of the chamber opposite to the portion of the wall defining the base of the chamber. Advantageously, the periphery of the wall defining the entrance to the chamber lies in a plane, and the at least one support structure protrudes from the exterior surface of a portion of the wall defining the base of the chamber, in a direction substantially perpendicular to this plane.

In addition to the at least one support structure described above, an eyelet may also be provided. Advantageously the inspection chamber further comprises at least one eyelet located on an exterior surface of the wall of the chamber. The at least one eyelet is preferably located at a position remote from the position of the at least one support structure.

The eyelet may be formed integrally with the wall defining the chamber. Alternatively, the eyelet may be formed separately from the wall defining the chamber, and may be permanently affixed to or detachably attached to the wall defining the chamber. The eyelet may be formed in a flange extending from the exterior surface of the wall defining the chamber.

Advantageously, at least one pair of eyelets is provided, each eyelet of the pair being positioned at opposite sides of the chamber from each other. Several pairs of eyelets may be provided, allowing the eyelets to be positioned around the chamber. Preferably two pairs of eyelets are provided, one pair being positioned together at one side of the chamber, and the other pair being positioned together at an opposite side of the chamber from the first pair.

The present invention also provides a plurality of inspection chambers, according to claim <NUM>.

Accordingly, the present invention allows a plurality of inspection chambers to be stacked in a stable manner during transportation and storage. This provides the advantages that the inspection chambers require less storage space and fewer packaging materials. This in turn decreases the cost associated with transporting and storing the inspection chambers.

The present invention will now be described by way of example only, and with reference to the following drawings, of which:.

<FIG> shows an inspection chamber <NUM> having two openings <NUM>, each opening being for receiving an inlet pipe (or a connection portion for an inlet pipe) and an outlet pipe (or a connection portion for an outlet pipe), respectively. A wall <NUM> surrounds and defines an interior of the chamber (reference numeral <NUM> in <FIG>). The wall <NUM> defines a base <NUM> of the chamber and a side wall <NUM>, the side wall extending around the chamber. The openings <NUM> are formed in the side wall <NUM> close to the base <NUM>. Opposite to the base <NUM> of the chamber is the top of the chamber which has an entrance defined by the rim or periphery <NUM> of the wall defining the chamber. The entrance provides access to the chamber. In this example, the exterior surface of the wall <NUM> is provided with reinforcing ribs <NUM>. The ribs <NUM> are optional and are provided where further strengthening of the inspection chamber is required. Two support structures in the form of arcuate portions 15A and 15B are provided on the exterior surface <NUM> of the wall <NUM> at the base portion <NUM>. The arcuate portions 15A and 15B are curved inwardly towards the center of the base of the inspection chamber, and have a radius of curvature slightly greater than the radius of curvature of the periphery <NUM> of the chamber wall <NUM>. The arcuate portions 15A and 15B are each also provided with side flanges <NUM>, and a notch <NUM> extending between the side flanges and the arcuate portions 15A and 15B. This permits several inspection chambers to be stacked one on top of the other in a stable manner, because, when the inspection chambers are stacked, the periphery <NUM> of the wall <NUM> of one inspection chamber is located in the notches <NUM> of another inspection chamber, and the arcuate portions 15A and 15B extend around part of the exterior surface <NUM> of the periphery of the wall <NUM>. Ideally, the arcuate portions fit snugly around the chamber wall of the adjacent chamber, thereby preventing lateral movement of the inspection chamber when it is stacked on another inspection chamber, and ensuring that the stacked inspection chambers remain in their stacked configuration during transportation. The arcuate portions may be formed as an integral part of the wall <NUM>, or may alternatively be permanently affixed to or removably attached to the exterior surface <NUM> of the wall as desired. The arcuate portions may take the form of a solid curved strip as shown in <FIG>, or may take the form of a rail mounted on a plurality of supports as shown in <FIG>.

Turning now to <FIG> shows an inspection chamber similar to that shown in <FIG>, except that the arcuate portions of the inspection chamber <NUM> of <FIG> are in the form of L-shaped flanges or rails <NUM> mounted on supports <NUM>. The arrangement shown in <FIG> has the advantage of requiring less material to form the arcuate portions. The L-shaped flange may be detachable from the supports <NUM>. The L-shaped flange <NUM> of <FIG> comprises a wall <NUM> and a base <NUM>. In this example, the radius of curvature of the arcuate portions 15A and 15B is greater than that of the periphery <NUM> of the wall of the chamber such that, when the inspection chambers are stacked, the wall <NUM> of the L-shaped flange <NUM> surrounds the exterior surface <NUM> of the periphery <NUM> of the chamber wall <NUM> whilst the base <NUM> of the L-shaped flange supports the periphery <NUM> of the chamber wall <NUM>. Thus it can be seen that the L-shaped flange provides a stable support for a neighbouring inspection chamber, permitting the inspection chambers to be easily and stably stacked together.

The arcuate portions also help to maintain the shape of the periphery <NUM> of the wall <NUM> defining the chamber by preventing deformation of the periphery <NUM> during transportation of the stacked inspection chambers.

It will be appreciated that, although the arcuate portions 15A and 15B of <FIG> and <FIG> are shown as having a radius of curvature slightly greater than that of the periphery <NUM> of the wall of the chamber, the radius of curvature of the arcuate portions could instead be slightly less than the radius of curvature of the periphery of the chamber wall. In this case, when the inspection chambers are stacked, the arcuate portions of one chamber will extend within the adjacent chamber abutting part of the interior surface of the periphery of the chamber wall.

Although <FIG> shows support structures having the form of an L-shaped flange, it will also be appreciated that support structures having a U-shaped cross-section could be provided instead. In this case, the periphery of the chamber wall of the inspection chambers fits within the central groove of the U-shape and the side portions of the U-shape extend around part of both the interior and exterior surfaces of the chamber wall, thereby providing stable stacking.

<FIG> shows an inspection chamber <NUM> having four openings <NUM>, for receiving four pipes. Arcuate portions 15A and 15B similar to those shown in <FIG> are provided on the exterior surface <NUM> of the wall <NUM> in the base region <NUM>. The inspection chamber further includes two more support structures <NUM>, each of the support structures <NUM> being located adjacent an opening and extending away from the exterior surface <NUM> of the wall <NUM> in a manner similar to that of the arcuate portions 15A and 15B. The support structures <NUM> are shown in <FIG> as being discrete portions having a rectangular cross section, however other cross-sectional shapes are possible. The support structures <NUM> are provided adjacent the openings which are not provided with an arcuate portion. The support structures <NUM> provide the stacked inspection chambers with even greater stability.

<FIG> shows an inspection chamber similar to that shown in <FIG>. As the inspection chamber of <FIG> is required to be more robust than that of <FIG>, the inspection chamber of <FIG> is provided with reinforcing ribs <NUM>. The inspection chamber <NUM> of <FIG> further differs from that of <FIG> in that the openings <NUM> for receiving the pipes are not configured to be <NUM>° apart from each other, but rather two of the pipes are configured to be offset by <NUM>° rather than <NUM>°. The inspection chamber <NUM> of <FIG> is provided, in a similar manner to that of <FIG>, with two further support structures <NUM>, which complement and aid the arcuate portions 15A and 15B in providing enhanced stability during stacking of the product.

<FIG> shows an inspection chamber similar to that shown in <FIG>, having openings <NUM> offset by <NUM>° rather than <NUM>°. In this example, no arcuate portions are provided, but instead three support structures <NUM> are provided, the support structures being in the form of discrete portions. Three support structures, located in the manner shown in <FIG>, allow stable stacking of the inspection chambers. Where four openings are provided, each offset by <NUM>° from each other, four discrete portions can be provided, one above each opening, for improved stacking stability.

<FIG> shows an inspection chamber similar to that depicted in <FIG>. However, the inspection chamber <NUM> of <FIG> does not include two arcuate portions, but instead has a single support structure in the form of a circular portion <NUM>. Circular portion <NUM> may be sized to fit inside the interior of an adjacent inspection chamber, or may be sized to fit around the exterior of the wall of an adjacent inspection chamber. The circular portion <NUM> may comprise an L-shaped flange similar to that of the arcuate portions 15A and 15B shown in <FIG>, to enhance the stability of stacked inspection chambers. Alternatively the circular portion <NUM> may have a U-shaped cross-section for receiving the periphery of the wall of an adjacent inspection chamber during stacking.

<FIG> shows an inspection chamber similar to that shown in <FIG> and <FIG> (in this example, having no reinforcing ribs <NUM>) in plan view, looking down upon the exterior surface <NUM> of the base portion <NUM>. A flange <NUM> is provided on opposite sides of the wall <NUM> defining the chamber, and eyelets <NUM> are provided in the flange. The flange <NUM> may be formed integrally with the wall <NUM>, or may be permanently affixed to or detachably attached to the exterior surface <NUM> of the wall <NUM>. In this example, two eyelets are provided on each side of the inspection chamber, however it would be equally possible to provide one eyelet on each side of the chamber. Alternatively, just one eyelet may be provided. The function of the eyelet will be described later. The inspection chamber <NUM> of <FIG> also includes two arcuate portions 15A and 15B.

The periphery <NUM> of the wall <NUM> of the chamber (which defines the rim of the chamber) is not visible in this plan view. However, the rim of the inspection chamber extends within a plane which is parallel to the plane of the surface of the paper on which <FIG> is drawn. Arcuate portions 15A and 15B protrude from the exterior surface <NUM> of the wall in a direction perpendicular to the plane of the rim (i.e., in the direction out of the plane of the surface of the paper towards the reader).

The eyelets <NUM> are for receiving a strap which is used to bundle together the inspection chambers and helps to keep them stably stacked together and to remain on a palette during transportation. Providing eyelets on both sides of the inspection chamber allows greater flexibility in stacking the products. Furthermore, more than one eyelet may be provided on one side of the product, as is the case in <FIG>. This provides greater flexibility when using straps to tie the inspection chambers together. For example, one of the eyelets might be used to tie the inspection chambers together whilst the other eyelet might be used to strap the inspection chambers to the palette.

Claim 1:
An inspection chamber stacking aid for placing between inspection chambers (<NUM>) to allow stable stacking of the inspection chambers, the stacking aid comprising:
at least one support structure (<NUM>,15A,15B,<NUM>) configured to extend from an exterior surface of a first inspection chamber (<NUM>) into an interior of a second inspection chamber (<NUM>) and/or adjacent to an exterior surface of a wall (<NUM>) defining the interior of the second inspection chamber;
wherein the at least one support structure (<NUM>,15A,15B,<NUM>) is configured to:
protrude from the exterior surface of a portion of the wall defining a base (<NUM>) of the first chamber in a direction substantially perpendicular to a plane in which a periphery (<NUM>) of the wall (<NUM>) of the second chamber lies, the periphery (<NUM>) defining the entrance to the second chamber and being located at the top of the second chamber opposite to the portion of the wall defining the base (<NUM>) of the chamber, characterized in that the at least one support structure (<NUM>,15A,15B,<NUM>) is sized to fit snugly against the interior surface of the wall (<NUM>) of the second chamber around at least part of the periphery (<NUM>) and/or to fit against the exterior surface of the wall of the second chamber around at least part of the periphery and thereby prevent lateral movement of the first and second inspection chamber (<NUM>) relative to each other in a direction perpendicular to the direction of stacking.