Patent Description:
Ground surface access assemblies, such as manhole covers, comprise a frame defining an opening and a cover which is mountable in the frame in the opening. In some instances, a hinge assembly may connect the cover to the frame to permit movement of the cover relative to the frame. The hinge assembly may comprise means to fix the position of the cover relative to the frame in an open condition of the ground surface access assembly to permit safe access to underground services via the opening.

Over time materials such as silt, dirt and debris from the roadway may enter the hinge assembly. Such ingress of materials may prevent the hinge assembly and the means to fix the position of the cover relative to the frame from properly functioning. Ground surface access assemblies typically comprise loose fitting hinge assemblies due to casting tolerances and tapered faces required for moulding purposes. Such loose-fitting hinge assemblies exacerbate the above problem as materials may readily enter such loose-fitting hinge assemblies.

Accordingly, there is a requirement to provide improved hinge assemblies for ground surface access assemblies.

<CIT> discloses a hinge structure of a lid for underground structures.

<CIT> discloses a hinge assembly for a ground surface access assembly according to the preamble of claim <NUM>.

According to various, but not necessarily all, examples of the disclosure there is provided a hinge assembly for a ground surface access assembly, the ground surface access assembly comprising a frame and a cover, the hinge assembly comprising a housing configured to receive a tab of the cover, the hinge assembly being configured such that the tab is moveable within the housing to permit the position of the cover relative to the frame to be adjusted, wherein the hinge assembly comprises a structure moveable in the housing by the tab of the cover, the structure comprises a barrel configured to receive the tab, said hinge assembly being characterized in that the barrel being rotatable within the housing by the tab to permit the position of the cover relative to the frame to be adjusted, and the barrel comprising a channel therethrough to receive the tab.

Possibly, in at least a closed condition of the ground surface access assembly, wherein the cover closes an opening in the frame, the structure substantially fills at least a volume defined by a lower part of the housing.

The hinge assembly may comprise a pocket extending from the housing, wherein the pocket is configured to receive the tab to fix the position of the cover relative to the frame. The pocket may comprise a pocket preserving device.

The pocket may communicate with the housing. The pocket may open into the housing. The pocket may comprise a pocket opening. The pocket preserving device may comprise a surface which is moveable between a condition in which the surface is relatively close to the pocket opening and a condition in which the surface is relatively further away from the pocket opening.

In the relatively close condition the surface may substantially abut the pocket opening. In the relatively close condition, the surface may substantially provide a seal between the opening and the pocket.

The surface may be moveable from the relatively close condition to the relatively further away condition by insertion of the tab of the cover through the pocket opening into the pocket, the tab acting on the surface to move the surface during insertion.

The pocket preserving device may be resiliently deformable. The pocket preserving device may comprise a resiliently deformable material. The resiliently deformable material may be a plastics material.

In the relatively close condition the pocket preserving device may be in a fully expanded condition and substantially fills the pocket. Possibly, in the fully expanded condition the pocket preserving device does not protrude from the pocket into the housing. In the relatively further away condition the pocket preserving device may be relatively compressed by the tab acting on the surface to move the surface during insertion into the pocket.

The hinge assembly may be configured such that the tab is extendable through the channel into the pocket when the channel and the pocket are aligned to fix the position of the cover relative to the frame.

In an example which is not claimed, the structure may comprise a resiliently deformable means configured to be compressed by the tab as the tab moves within the housing as the cover is opened and configured to expand as the tab moves within the housing as the cover is closed, wherein in a closed condition of the ground surface access assembly wherein the cover closes an opening in the frame, the resiliently deformable means is in an expanded condition. In an expanded condition the resiliently deformable means may substantially fill the volume defined by the lower part of the housing.

The housing may comprise an opening for receiving the tab of the cover. Possibly, the opening in the housing is off-set from the pocket opening.

According to various, but not necessarily all, examples of the disclosure there is provided a ground surface access assembly, the assembly comprising:.

The frame opening may be substantially circular in plan view.

According to various, but not necessarily all, examples of the disclosure there is provided a method of fixing the position of a cover relative to a frame of a ground surface access assembly, the method comprises:
adjusting the position of the cover relative to the frame to move a tab of the cover within a housing of a hinge assembly of the ground surface access assembly, wherein the hinge assembly comprises a structure moveable in the housing by the tab of the cover, the structure comprises a barrel configured to receive the tab, said method being characterized in that the barrel being rotatable within the housing by the tab to permit the position of the cover relative to the frame to be adjusted, and the barrel comprising a channel therethrough to receive the tab.

The method may comprise locating the tab in a pocket of the housing to fix the position of the cover relative to the frame, wherein the pocket comprises a pocket preserving device.

Locating the tab in the pocket may move a surface of the pocket preserving device between a condition in which the surface is relatively close to the pocket opening to a condition in which the surface is relatively further away from the pocket opening.

The hinge assembly, ground surface access assembly, and method may comprise any of the features described in any of the preceding statements or following description.

According to various, but not necessarily all, examples of the disclosure there may be provided examples as claimed in the appended claims.

The figures illustrate a hinge assembly <NUM> for a ground surface access assembly <NUM>, and a ground surface access assembly <NUM> comprising a hinge assembly <NUM>.

The ground surface access assembly <NUM> comprises a frame <NUM> defining a frame opening <NUM>, and a cover <NUM> mountable to the frame <NUM> in the frame opening <NUM>. The ground surface access assembly <NUM> is openable by adjusting the position of the cover <NUM> relative to the frame <NUM> to permit access to underground services via the opening <NUM>.

The hinge assembly <NUM> connects the cover <NUM> to the frame <NUM> to permit movement of the cover <NUM> relative to the frame <NUM>.

The frame <NUM> comprises a side wall <NUM> which defines the frame opening <NUM>. A flange <NUM> extends outwardly from a lowermost part of the side wall <NUM>. In the illustrated example, the frame opening <NUM> is substantially circular in plan view. Accordingly, the cover <NUM> is substantially circular in plan view. In other examples, the frame opening <NUM> may have a different shape, for example, the frame opening <NUM> may be substantially square or rectangular. Accordingly, in such other examples the cover <NUM> may be shaped to correspond to the frame opening <NUM>, for instance, the cover <NUM> may be substantially square or rectangular in plan view.

The hinge assembly <NUM> comprises a housing <NUM> configured to receive a tab <NUM> of the cover <NUM>. The tab <NUM> is the end portion of the cover <NUM>. The tab <NUM> is the part of the cover <NUM> which is engageable with the hinge assembly <NUM>. Accordingly, in use the tab <NUM> may be pivoted about the housing <NUM>.

The hinge assembly <NUM> is configured such that the tab <NUM> is moveable within the housing <NUM> to permit the position of the cover <NUM> relative to the frame <NUM> to be adjusted.

In the illustrated examples, the hinge assembly <NUM> comprises a structure <NUM> moveable in the housing <NUM> by the tab <NUM> of the cover <NUM>. In some examples, in at least a closed condition of the ground surface access assembly <NUM>, wherein the cover <NUM> closes the frame opening <NUM>, the structure <NUM> substantially fills a volume defined by a lower part <NUM> of the housing <NUM>. In the illustrated examples, a volume defined by the lower part <NUM> of the housing <NUM> is the volume within the housing underlying the tab <NUM> in a closed condition of the assembly <NUM>.

In some examples, in at least a closed condition of the ground surface access assembly <NUM>, the structure <NUM> substantially fills a volume defined by the lower part <NUM> of the housing <NUM>, and a volume defined by an upper part <NUM> of the housing <NUM>. In the illustrated examples, a volume defined by an upper part <NUM> of the housing <NUM> is the volume within the housing overlying the tab <NUM> in a closed condition of the assembly <NUM>.

In some examples, in at least a closed condition of the ground surface access assembly <NUM>, the structure <NUM> at least extends along an in use lower arc of the path along which the tab <NUM> will travel in use. In other examples, in a closed condition of the ground surface access assembly <NUM>, the structure <NUM> extends both along respective in use lower and upper arcs of the path along which the tab <NUM> will travel in use. In the illustrated examples, the lower arc of the path is the path taken by the tab <NUM> as it moves through the lower part <NUM> of the housing <NUM> as the cover <NUM> is opened. In the illustrated examples, the upper arc of the path is the path taken by the tab <NUM> as it moves through the upper part <NUM> of the housing <NUM> as the cover <NUM> is opened.

The structure <NUM> substantially prevents the ingress of materials such as silt, dirt and debris from the roadway into the hinge assembly <NUM> which may otherwise jam the hinge assembly <NUM> and prevent opening of the ground surface access assembly <NUM>.

In the illustrated examples, the hinge assembly <NUM> comprises a pocket <NUM> extending from the housing <NUM>. The pocket <NUM> is configured to receive the tab <NUM> of the cover <NUM> to fix the position of the cover <NUM> relative to the frame <NUM>. The pocket <NUM> comprises a pocket preserving device <NUM>. The pocket <NUM> opens into the housing <NUM> and therefore communicates with the housing <NUM>.

<FIG> illustrate a first example of the disclosure in different conditions of use.

The hinge assembly <NUM> of the first example comprises a structure <NUM> in the form of barrel <NUM> configured to receive the tab <NUM>. <FIG> provides an illustration of the barrel <NUM> separate from the hinge assembly <NUM>. The barrel <NUM> may be formed from a plastics material, for example, polypropylene or polyethylene. The barrel <NUM> may be self-lubricating or of low surface-friction.

The barrel <NUM> is rotatable within the housing <NUM> by the tab <NUM> to permit the position of the cover <NUM> relative to the frame <NUM> to be adjusted. The barrel <NUM> comprises a channel <NUM> therethrough to receive the tab <NUM>. The tab <NUM> of the cover <NUM> extends the length of the channel <NUM>.

The barrel <NUM> therefore controls the movement of the tab <NUM> within the housing <NUM>. The barrel <NUM> permits a smooth controlled movement of the tab <NUM> within the housing <NUM>.

The barrel <NUM> substantially fills a volume defined by the housing <NUM>, subject to a clearance fit to permit a smooth controlled movement of the barrel <NUM> within the housing <NUM>.

A closed condition of the ground surface access assembly <NUM> is illustrated in <FIG>. In the closed condition of the ground surface access assembly <NUM> the cover <NUM> closes the opening <NUM>. In the closed condition the cover <NUM> bears against a seal <NUM>. Accordingly, in use the seal <NUM> is under compression. The seal <NUM> is a mechanical seal which in use fills the space between a mating surface <NUM> on the cover <NUM> and a mating surface <NUM> on a cover receiving portion <NUM> of the frame <NUM>. The seal <NUM> substantially prevents leakage from or into the ground surface access assembly <NUM> while under compression. In use, the seal <NUM> may substantially prevent leakage of fluids such as liquids and gases. The seal <NUM> may be a gasket.

<FIG> and <FIG> illustrate a condition of the ground surface access assembly <NUM> in which the cover <NUM> has been displaced from the opening <NUM> of the frame <NUM> to a small extent. The barrel <NUM> has rotated within the housing <NUM> such that the position of the cover <NUM> relative to the frame <NUM> has been adjusted from the position illustrated in <FIG>. The barrel <NUM> is in use rotated within the housing by moving the cover <NUM> relative to the frame <NUM>.

<FIG> illustrate a condition of the ground surface access assembly <NUM> in which the cover <NUM> has been displaced from the opening <NUM> of the frame <NUM> to the maximum extent permitted by the arrangement. The barrel <NUM> has further rotated within the housing <NUM> such that the position of the cover <NUM> relative to the frame <NUM> has been further adjusted from the position illustrated in <FIG>. In the illustrated example, the cover <NUM> is inclined relative to the frame <NUM> at an angle of about <NUM> degrees.

In <FIG> the barrel <NUM> has been rotated within the housing such that the channel <NUM> of the barrel <NUM> and the pocket <NUM> are aligned.

In <FIG> and <FIG>, the tab <NUM> of the cover <NUM> extends through the channel <NUM> and is received in the pocket <NUM> to fix the position of the cover <NUM> relative to the frame <NUM>. In use, the tab <NUM> drops into the pocket when the channel <NUM> of the barrel <NUM> and the pocket <NUM> are aligned. In this condition the cover <NUM> is seated in a seating portion <NUM> of the hinge assembly <NUM>. The seating portion <NUM> is configured to receive an abutment portion <NUM> of the cover <NUM>. When the abutment portion <NUM> is seated in the seated portion <NUM> the tab <NUM> of the cover <NUM> extends to the maximum extent permitted by the arrangement into the pocket <NUM>. Fixing the position of the cover <NUM> relative to the frame <NUM> allows access to the opening <NUM> without the risk that the cover <NUM> could fall back and cause injury.

The pocket <NUM> is therefore a means to fix the position of the cover <NUM> relative to the frame <NUM> in an open condition of the ground surface access assembly <NUM> to permit safe access to underground services via the opening.

As the cover <NUM> moves from the position illustrated in <FIG> to the seating position illustrated in <FIG> and <FIG> the tab <NUM> acts on the pocket preserving device <NUM>.

The pocket comprises a pocket opening <NUM>. The pocket preserving device <NUM> comprise a surface <NUM> which is moveable between a condition in which the surface <NUM> is relatively close to the pocket opening <NUM> (<FIG>) and a condition in which the surface <NUM> is relatively further away from the pocket opening <NUM> (<FIG>). The surface <NUM> of the pocket preserving device <NUM> is moveable by the tab <NUM> acting on the surface <NUM> as the tab <NUM> moves into the pocket <NUM> in use. As illustrated, the tab <NUM> is inserted through the pocket opening <NUM> into the pocket <NUM>.

In the illustrated example, in the relatively close condition the surface <NUM> substantially abuts the pocket opening <NUM>. The surface <NUM> substantially provides a seal between the opening <NUM> and the pocket <NUM>. Accordingly, ingress of materials such as silt, dirt and debris from the roadway into the pocket <NUM> is prevented by the pocket preserving device <NUM>. Such ingress of material may otherwise accumulate in the pocket <NUM> and prevent entry of the tab <NUM> of the cover into the pocket <NUM>. It would not therefore be possible to reliably fix the position of the cover <NUM> relative to the frame <NUM> to allow access to the opening <NUM> without the risk that the cover <NUM> may fall back and cause injury.

In the illustrated example, the pocket preserving device <NUM> is a resiliently deformable material. The deformable material is resiliently compressible. In the relatively close condition the pocket preserving device <NUM> is in a fully expanded condition and substantially fills the pocket <NUM>. In the fully expanded condition the pocket preserving device <NUM> does not protrude from the pocket <NUM> into the housing <NUM>. The surface <NUM> is flush with the inner surface <NUM> of the housing <NUM>. In the relatively further away condition the pocket preserving device <NUM> is relatively compressed by the tab <NUM> acting on the surface <NUM> to move the surface <NUM> during insertion into the pocket <NUM>.

The tab <NUM> can in use be lifted from the pocket <NUM> by a user to provide the condition of the ground surface access assembly <NUM> illustrated in <FIG>, wherein the pocket preserving device <NUM> is in a fully expanded condition and substantially fills the pocket <NUM>. In this condition the barrel <NUM> can again be rotated in the housing <NUM>. The pocket preserving device <NUM> automatically returns to its fully expanded condition when no longer under compression, that is, when the tab <NUM> is lifted from the pocket <NUM>.

The resiliently deformable material may comprise plastics material. The resiliently deformable material may comprise foam materials, expanding foam materials, closed cell foam materials, cellular elastomers, cellular plastics (for example, low and high-density polyurethane), cellular plastics with elastomeric properties, other cellular or solid materials having elastomeric properties, cellular nitrile, cellular neoprene, cellular ethylene propylene diene terpolymer.

The deformable material is elastic in its recovery after compression, that is, it does not take on a permanent set during its temporary compression.

Suitable materials could be injected or sprayed as curable foam materials into the pocket <NUM> to form the pocket preserving device <NUM>. Materials will be selected in accordance with expected contaminants and elastic properties. In other examples, the pocket preserving device <NUM> could be pre-formed before it is located in the pocket <NUM>.

The pocket preserving device <NUM> material may be substantially weather resistant and rot resistant.

<FIG> illustrate a condition of the ground surface access assembly <NUM> in which the cover <NUM> has been displaced from the opening <NUM> of the frame <NUM> to an intermediate extent in which the cover <NUM> extends substantially perpendicular to the frame <NUM>. In use, the cover <NUM> extends substantially vertically from the frame <NUM>.

In the illustrated example, the housing <NUM> comprises an opening <NUM> for receiving the tab <NUM> of the cover <NUM>. Accordingly, when the channel <NUM> of the barrel <NUM> is aligned with the opening <NUM> of the housing <NUM> as illustrated in <FIG>, the tab <NUM> can be lifted from the barrel <NUM> and out through the opening <NUM>. This allows the cover <NUM> to be completely removed from the frame <NUM> if required.

The opening <NUM> in the housing <NUM> is misaligned with the opening <NUM> to the pocket <NUM>. The opening <NUM> in the housing <NUM> and the opening <NUM> to the pocket <NUM> are therefore off-set. This arrangement prevents a user inadvertently removing the cover <NUM> when lifting the tab <NUM> from the pocket <NUM> as described in relation to <FIG>.

To remove the cover <NUM> from the frame <NUM> starting from the position illustrated in <FIG> and <FIG>, the tab <NUM> must first be removed from the pocket <NUM> by lifting the cover <NUM> to the position illustrated in <FIG>. The barrel <NUM> must then be rotated within the housing by moving the cover <NUM> relative to the frame <NUM> to the position illustrated in <FIG> to align the channel <NUM> of the barrel <NUM> with the opening <NUM> of the housing <NUM>. As illustrated in <FIG>, the tab <NUM> can then be lifted from the barrel <NUM> and out through the opening <NUM> to remove the cover <NUM> from the frame <NUM>.

<FIG> illustrate a second example of the disclosure in different conditions of use. The second example does not fall within the scope of the appended claims.

Many features of the second example are similar to those previously described, and where features are the same or similar the same reference numerals have been used and these features will not be described again for the sake of brevity. In fact, the only differences relative to the first example are as follows.

In the second example, the hinge assembly <NUM> comprises a structure <NUM> in the form of a resiliently deformable means <NUM> rather than a barrel <NUM> into which the tab <NUM> is received.

<FIG> and <FIG> illustrate the second example in a closed condition of the ground surface access assembly <NUM> wherein the cover <NUM> closes the opening <NUM>. In this condition the resiliently deformable means <NUM> is in an expanded condition and substantially fills at least a volume defined by a lower part <NUM> of the housing <NUM>. The resiliently deformable means <NUM> is substantially elongate in cross section. The resiliently deformable means <NUM> in an expanded condition is shaped to correspond to at least the volume defined by the lower part <NUM> of the housing <NUM> in the closed condition of the ground surface access assembly <NUM>. In the closed condition, the tab <NUM> substantially closes the housing <NUM>. The tab <NUM> comprises an arcuate end portion <NUM> shaped to correspond to an arcuate portion of the inner surface <NUM> of the housing <NUM>. The corresponding arcuate surfaces permit a smooth movement of the tab <NUM> within the housing <NUM>.

<FIG> illustrates a condition of the ground surface access assembly <NUM> in which the cover <NUM> has been displaced from the opening <NUM> of the frame <NUM> to a small extent. The tab <NUM> has moved within the housing <NUM> and compressed the resiliently deformable means <NUM> to a small extent against the inner surface <NUM> of the housing <NUM>.

<FIG> and <FIG> illustrate a condition of the ground surface access assembly <NUM> in which the cover <NUM> has been displaced from the opening <NUM> of the frame <NUM> to the maximum extent permitted. The tab <NUM> has further moved within the housing <NUM> and compressed the resiliently deformable means <NUM> against the inner surface <NUM> of the housing <NUM> to the maximum extent permitted. In <FIG>, the tab <NUM> is aligned with the pocket <NUM> but has not yet been lowered (or allowed to drop) into the pocket <NUM>. In <FIG>, the tab <NUM> has been lowered into the pocket <NUM>. Accordingly, the pocket <NUM> has received the tab <NUM>.

<FIG> illustrates a condition of the ground surface access assembly <NUM> in which the cover <NUM> has been displaced from the opening <NUM> of the frame <NUM> to an intermediate extent in which the cover <NUM> extends substantially perpendicular to the frame <NUM>. In use, the cover <NUM> extends substantially vertically from the frame <NUM>. In this condition, the tab <NUM> can be lifted from the housing <NUM> and out through the opening <NUM> in the housing <NUM>. The tab <NUM> has moved within the housing <NUM> and the resiliently deformable means <NUM> has expanded relative to the condition illustrated in <FIG> and <FIG>. The resiliently deformable means <NUM> continues to expand as the cover <NUM> is closed and the tab <NUM> is moved in the housing <NUM> back to the closed position of the ground surface access assembly <NUM> illustrated in <FIG> and <FIG>.

Accordingly, the resiliently deformable means <NUM> is configured to be compressed by the tab <NUM> as the tab <NUM> moves within the housing <NUM> as the cover <NUM> is opened. Accordingly, the resiliently deformable means <NUM> is configured to expand as the tab <NUM> moves away from the resiliently deformable means <NUM> within the housing <NUM> as the cover <NUM> is closed.

The resiliently deformable means <NUM> may comprise a resiliently deformable material. The resiliently deformable material of the resiliently deformable means <NUM> may comprise the same material as the material of the pocket preserving device <NUM>. The resiliently deformable means <NUM> is resiliently compressible.

Examples of the disclosure provide a number of advantages as detailed above. Furthermore, the hinge assembly <NUM> substantially prevents leakage of fluids from or into the ground surface access assembly <NUM>. Accordingly, in a closed condition of the ground surface access assembly <NUM> the hinge assembly <NUM> does not undermine the seal <NUM>. Furthermore, the barrel <NUM> in the first example and the resiliently deformable means <NUM> in the second example provide a close fitting hinge assembly <NUM> which substantially prevent the ingress of materials such as silt, dirt and debris from the roadway into the hinge assembly <NUM> which may otherwise jam the hinge assembly <NUM> and prevent opening of the ground surface access assembly <NUM>. Furthermore, the close-fitting hinge assembly <NUM> results in a more closely controlled actuation of the cover <NUM> relative to the frame <NUM> than is the case with conventional loose-fitting hinge assemblies. Furthermore, because the hinge assembly <NUM> is close fitting additional features on the cover and/or frame to maintain alignment of the cover and frame as the cover is actuated are not required as is the case with conventional ground surface access assembly with loose-fitting hinge assemblies.

As described above, the pocket preserving device <NUM> prevents ingress of such materials into the pocket <NUM>, for instance should any fine materials pass the barrel <NUM> in the first example and the resiliently deformable means <NUM> in the second example toward the opening <NUM> of the pocket <NUM>.

Example of the disclosure therefore provide ground surface access assemblies <NUM> which are readily openable throughout the service life of the assembly <NUM>, and in which the cover <NUM> can be fixed relative to the frame <NUM> to allow safe access to the opening <NUM>.

In some examples a ground surface acces assembly <NUM> may comprise a plurality of cooperating hinge assemblies <NUM>.

Claim 1:
A hinge assembly (<NUM>) for a ground surface access assembly (<NUM>), the ground surface access (<NUM>) assembly comprising a frame (<NUM>) and a cover (<NUM>), the hinge assembly (<NUM>) comprising a housing (<NUM>) configured to receive a tab (<NUM>) of the cover (<NUM>), the hinge assembly (<NUM>) being configured such that the tab (<NUM>) is moveable within the housing (<NUM>) to permit the position of the cover (<NUM>) relative to the frame (<NUM>) to be adjusted, wherein the hinge assembly (<NUM>) comprises a structure (<NUM>) moveable in the housing (<NUM>) by the tab (<NUM>) of the cover (<NUM>), the structure (<NUM>) comprises a barrel (<NUM>) configured to receive the tab, said hinge assembly (<NUM>) being characterized in that the barrel (<NUM>) being rotatable within the housing (<NUM>) by the tab (<NUM>) to permit the position of the cover (<NUM>) relative to the frame (<NUM>) to be adjusted, and the barrel (<NUM>) comprising a channel (<NUM>) therethrough to receive the tab (<NUM>).