GB2557562A

GB2557562A - Ground surface access assembly

Info

Publication number: GB2557562A
Application number: GB1604263.2A
Authority: GB
Inventors: John Gibson Simon; Turner Barry
Original assignee: Wrekin Holdings Ltd
Current assignee: Wrekin Holdings Ltd
Priority date: 2016-03-11
Filing date: 2016-03-11
Publication date: 2018-06-27
Also published as: GB201604263D0

Abstract

A ground surface access assembly including a cover member 12. The cover member includes a reinforcement arrangement 16 and one or more seating surfaces 18 which contact a support frame. The reinforcing arrangement may be provided as ribs and may be forked to form two fingers. The fingers may be curved 106 and may have seating surfaces 46 located at the end. Ribs may be provided along two separate axis and may include multiple forked sections. The ribs may vary in depth and width along their length so as to form thicker and thinner portions. The arrangements of the reinforcing ribs may serve to increase the strength of the cover.

Description

(71) Applicant(s):

Wrekin Holdings Limited (Incorporated in the United Kingdom)

Unit 1a, Europa Way, Britannia Enterprise Park, LICHFIELD, Staffordshire, WS14 9TZ, United Kingdom (72) Inventor(s):

Simon John Gibson Barry Turner (74) Agent and/or Address for Service:

IP-Active.com Ltd The TechnoCentre,

Coventry University Technology Park, Puma Way, Coventry, CV1 2TT, United Kingdom (51) INT CL:

E02D 29/14 (2006.01) (56) Documents Cited:

GB 2299603 A EP 0541350 A2

WO 2008/025029 A2 WO 2005/111318 A1 CN 204570744 U US 7160051 B1 (58) Field of Search:

INT CL E02D

Other: EPODOC; WPI; Patent Fulltext; Internet (54) Title ofthe Invention: Ground surface access assembly Abstract Title: Manhole cover with forked reinforcing ribs (57) Aground surface access assembly including a cover member 12. The cover member includes a reinforcement arrangement 16 and one or more seating surfaces 18 which contact a support frame. The reinforcing arrangement may be provided as ribs and may be forked to form two fingers. The fingers may be curved 106 and may have seating surfaces 46 located at the end. Ribs may be provided along two separate axis and may include multiple forked sections. The ribs may vary in depth and width along their length so as to form thicker and thinner portions. The arrangements ofthe reinforcing ribs may serve to increase the strength ofthe cover.

The claims were filed later than the filing date but within the period prescribed by Rule 22(1) of the Patents Rules 2007. At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

1/7

110

2/7

110

3/7

4/7

210

34,36

5/7

Fig. 11

6/7

Fig. 12

7/7

16,24,80 40i 38i

40o 38o i 90

108,82

Fig. 13

Ground Surface Access Assembly

The present invention relates to ground surface access assemblies.

Ground surface access assemblies such as gullies and manhole covers and frames are used in areas such as roadway surfaces to provide access to underground services such as, for instance, drainage services and cable ducting. Such assemblies are commonly formed of cast iron and include a frame defining an access opening and a removable or openable cover or grating which is mounted to the frame in the opening. Typically, a cover has a solid plate-like upper surface, while a grating has a surface defining a plurality of holes to permit water drainage therethrough. For convenience, in this specification, both gratings and covers will be referred to as cover members.

The assemblies have to be constructed to withstand a specified test regime which includes withstanding a test load, the amount of which is dependent on the particular location and trafficking for which the assembly is designed.

The testing regime applicable to ground surface access assemblies for use in locations such as roadways is currently set out in European Standard EN124. In testing, an assembly must withstand a specified design load applied through a pad or plate to the cover or covers over the central part of the opening without an undue amount of permanent deformation resulting. Further constraints on the designers of such assemblies include ensuring that the product can be relatively easily manufactured; that product weight is minimised for cost and handling reasons; ensuring ease and safety of stacking of products for efficient transportation and storage; and ensuring ease of use for installers.

In this specification, the terms inner, outer, inwardly and outwardly, when used in relation to the frame, are used with respect to the opening, which is inward of the frame, and the terms upward and downward are used in relation to the in use orientation of a ground surface access assembly, in which downward means down into the ground.

In this specification, the terms “height”, “depth”, “width” and “length” are used relative to the plane ofthe ground surface, in which height and depth are dimensions transverse (normal) to the ground plane, and width and length are dimensions in or parallel to the ground plane. In an installed condition, the upper surface of a ground surface access assembly is substantially planar, and substantially coplanar with or substantially parallel to the ground plane. The term “plan” is used of a viewpoint looking downwards or upwards towards the upper surface and the ground plane. The term “side” or “side profile” is used of a viewpoint looking along or parallel to the upper surface and the ground plane.

In this specification, “load efficiency” means the load capability/product weight. Improved load efficiency means that for a given product weight the product has an improved load capability, ie it can withstand a higher load for a given product weight.

According to a first aspect of the present invention, there is provided a ground surface access assembly, the assembly including a cover member, the cover member including a reinforcement arrangement and one or more seating surfaces which, in an assembled condition, contact a support frame and transmit load therethrough, the reinforcement arrangement being arranged, in a test condition, to transmit load applied to a load test area on an in use upper surface of the cover member through the seating surface(s).

Possibly, the reinforcement arrangement includes one or more reinforcement members, the or each of which may extend downwardly in use relative to the upper surface.

Possibly, the or each reinforcement member is generally aligned along a reinforcement axis. Possibly, the reinforcement axis extends through the load test area when viewed in plan looking on the in use upper surface.

Possibly, the or one reinforcement member comprises a forked reinforcement member which extends along a forked reinforcement member axis. Possibly, the forked reinforcement member includes an arm portion, in which the forked reinforcement member comprises a single arm. Possibly, the forked reinforcement member comprises a plural finger portion, in which the forked reinforcement member comprises a plurality of fingers. Possibly, the forked reinforcement member includes a fork junction at which the forked reinforcement member changes from the arm portion to the plural finger portion.

Possibly, the plural finger portion comprises two fingers, each of which may extend transversely outwardly from the forked reinforcement member axis. Possibly, the fingers extend outwardly on opposite sides of the forked reinforcement member axis. Possibly, each finger extends outwardly at an angle to the forked reinforcement member axis. Possibly, each finger extends outwardly at substantially the same angle as the other to the forked reinforcement member axis. Possibly, the angle is no more than 60°, and may be no less than 5°.

Possibly, the fingers are similar in size and shape and may be substantially symmetrical about the forked reinforcement member axis.

Possibly, the fingers diverge away from each other, moving away from the fork junction. Possibly the fingers are curved when viewed in plan looking on the in use upper surface.

Possibly, the finger portion does not include a finger which extends along the forked reinforcement member axis.

Possibly, the finger portion is located at or towards an edge of the cover member.

Possibly, each finger comprises one of the seating surfaces.

Possibly, in the test condition, the test load area is located over the arm portion when viewed in plan looking on the in use upper surface.

Possibly, the forked reinforcement member includes two fork junctions. The arm portion may be located between the fork junctions, with one plural finger portion at or towards each end of the forked reinforcement member.

Possibly, in the test condition, the test load area is located between the fork junctions when viewed in plan looking on the in use upper surface. The forked reinforcement member may be substantially symmetrical lengthwise about a central point of the forked reinforcement member.

Possibly, the cover member includes one or more auxiliary seating surfaces which, in a deformed condition, contact the support frame and transmit load therethrough, but in an undeformed condition do not contact the support frame. Possibly, in the undeformed condition, a gap is defined between each of the auxiliary seating surfaces and the support frame.

Possibly, each finger seating surface is one of the auxiliary seating surfaces. Possibly, each finger seating surface is located at or below an end of the respective finger.

Possibly, one reinforcement member includes a depth minimum, where the depth of the respective reinforcement member is at a minimum, which minimum may not be located at an end of the reinforcement member.

Possibly, the depth minimum is located at a distance of no less than 10%, and desirably no less than 20% as a proportion of the unsupported span half-length of the respective reinforcement member, as measured from the seating surface towards an in use central vertical axis of an opening in which the cover member is located.

Possibly, the depth minimum is located at a distance of no more than 40%, and desirably no more than 30% as a proportion of the unsupported span half-length of the respective reinforcement member, as measured from the seating surface towards an in use central vertical axis of an opening in which the cover member is located..

Possibly, one reinforcement member includes a constant depth region, in which region the depth of the respective reinforcement member is substantially constant, and may be at a maximum. Possibly, the constant depth region extends over a central region of the respective reinforcement member.

Possibly, the constant depth region extends over a distance of at least 40% and possibly no more than 60%, and desirably at least 45% and possibly no more than 55%, of the unsupported span half-length of the respective reinforcement member, as measured from the central vertical axis towards the seating surface

Possibly, one reinforcement member comprises a first reinforcement member which is aligned along or parallel to a first reinforcement axis.

Possibly, the first reinforcement member includes an inner central part which is relatively deep and may be relatively narrow in width. Possibly, the inner central part is substantially similar in length to the diameter of the load test area.

Possibly, the first reinforcement member includes outer central parts, one of which may be located on either side of the inner central part, and which may be relatively deep and may be relatively wide. Possibly, the first reinforcement member includes an inner junction where each outer central part meets the inner central part.

Possibly, the first reinforcement member includes end parts, one of which may be located at or towards each end of the first reinforcement member, and one of which may be located on the outer side of each outer central part. Possibly, the first reinforcement member includes an outer junction where each outer central part meets the respective end part. Possibly, each end part is relatively shallow in depth and may be relatively wide. Possibly, each end part reduces in depth moving inwardly, and may substantially reduce to a minimum at the outer junction. Possibly, the depth minimum is located at the outer junction.

Possibly, the first reinforcement member includes bracing surfaces, which slope inwardly and upwardly towards the upper surface.

Possibly, the first reinforcement axis extends between two of the seating surfaces.

Possibly, another reinforcement member comprises a second reinforcement member which is aligned along or parallel to a second reinforcement axis, which may be orientated at substantially 90° to the first reinforcement axis, and may extend from one of the seating surfaces, and may extend substantially towards a central point of the test load area.

Possibly, the second reinforcement member comprises a forked reinforcement member. The second reinforcement member may include any of the features of the forked reinforcement member described above. The second reinforcement member may be asymmetrical lengthwise.

Possibly, the second reinforcement member includes an inner plural finger portion. Possibly, each finger of the inner plural finger portion extends to meet the first reinforcement member, and may meet the first reinforcement member at or in the vicinity of the inner junction.

Possibly, the second reinforcement member includes an outer plural finger portion, which is located at or towards an edge, possibly a corner, of the cover member. Possibly, the one of the seating surfaces is located at or towards the ends of the fingers of the outer plural portion.

Possibly, the second reinforcement member includes an arm portion located between the inner plural finger portion and the outer plural finger portion.

Possibly, the inner finger portion of the second reinforcement member is relatively deep and is relatively narrow in width, and may be similar in depth and width to the inner central part of the first reinforcement member.

Possibly, part of the or one or some reinforcement members comprise a test load perimeter reinforcement arrangement, which may extend around at least part of a perimeter of the test load area when viewed in plan looking on the in use upper surface. Possibly, the test load perimeter reinforcement arrangement includes two of the fingers of the inner plural finger portion, which may be orientated substantially at 90° to each other.

Possibly, the first reinforcement member includes a pair of the aforesaid depth minima, spaced apart, which minima may not be located at the ends of the first reinforcement member.

Possibly, the second reinforcement member includes the aforesaid depth minimum, which minimum may not be located at the end of the second reinforcement member.

Possibly, each of the first and second reinforcement members include a constant depth region, in which region the depth of the respective reinforcement member is substantially constant, and may be at a maximum. Possibly, the constant depth region extends over a central region of the first reinforcement member. Possibly, the constant depth region extends over an innermost region of the second reinforcement member.

Possibly, the ground surface access assembly includes a pair of cover members, which may be substantially similar, so that, in an assembled condition, the test load perimeter reinforcement arrangements of the two covers extend substantially wholly or around a greater part of the test load area when viewed in plan looking on the in use upper surface.

Possibly, the ground surface access assembly includes a frame, which may define an opening, in which one or more of the cover members locates in use.

Possibly, the ground surface access assembly is formed by a process including casting and may be formed of a metal and may be formed of a cast iron, and may be formed of a ductile cast iron.

Possibly, the ground surface access assembly is arranged to comply with European Standard EN124.

According to a second aspect of the present invention, there is provided a method of providing access to an underground service, the method including providing a ground surface access assembly, the assembly including a cover member, the cover member including a reinforcement arrangement and one or more seating surfaces which, in an assembled condition, contact a support frame and transmit load therethrough, the reinforcement arrangement being arranged, in a test condition, to transmit load applied to a load test area on an in use upper surface of the cover member through the seating surface(s).

Possibly, the assembly includes any of the features described in any of the preceding statements or following description. Possibly, the method includes any of the steps described in any of the preceding statements or following description.

Embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:Fig. 1 is a plan view from above of a ground surface access assembly in an assembled condition, and in a test condition with a test member in position;

Fig. 2 is a plan view from above of a frame of the ground surface access assembly;

Fig. 3 is a plan view from above of a cover member of the assembly;

Fig. 4 is a perspective view from below and one side of the cover member;

Fig. 5 is a side view of the cover member with the test member in position, looking along a reinforcement axis;

Fig. 6 is a side cross sectional view through the reinforcement axis of the cover member, with the test member in position;

Fig. 7 is a view of a relatively enlarged detail of Fig. 6 as indicated by the box labelled VII in Fig. 6;

Fig. 8 is a plan view from above of another ground surface access assembly in an assembled condition, with a test load area indicated;

Fig. 9 is a plan view from below of the ground surface access assembly of Fig. 8, with the test load area indicated in dashed lines;

Fig. 10 is a perspective view from below and one side of a cover member of the assembly of Figs. 8 and 9;

Fig. 11 is a side view looking on a relatively longer side of the cover member of Fig. 10 with a test member in position;

Fig. 12 is a composite of views for comparison purposes of part of a first reinforcement member of the cover member of Figs. 10 and 11, comprising an upper figure which is a plan view from below (ie part of Fig. 9) and a lower figure which is a side view looking on a relatively longer side of the cover member (ie part of Fig. 11); and

Fig. 13 is a composite of views for comparison purposes of a second reinforcement member of the cover member, of Figs. 10 to 12, comprising an upper figure which is a plan view from below (ie part of Fig. 9), and a lower figure which is a side view looking on a relatively shorter side of the cover member along the length ofthe first reinforcement member.

Figs. 1 to 7 show a first ground surface access assembly 10, the assembly 10 including a cover member 12. The cover member 12 includes a reinforcement arrangement 16 and one or more seating surfaces 18 which, in an assembled condition, contact a support frame 14 and transmit load therethrough. The reinforcement arrangement 16 is arranged, in a test condition, to transmit load applied to a load test area 20 on an in use upper surface 26 of the cover member through the seating surface(s) 18.

In the example shown in Figs. 1 to 7, the assembly 10 is in the form of a ground surface access assembly for a gully and includes a single cover member 12, which is in the form of a gully cover or grating. The assembly 10 is rectangular, having a pair of relatively longer sides 110 and a pair of relatively shorter sides 112. The assembly 10 includes the frame 14 which defines an opening 74, which is similarly rectangular and has a central vertical axis 72. In the assembled condition, the cover member 12 locates in or above the opening 74 and is removable or openable to permit access through the opening 74 to underground services therebelow.

In the example shown, the reinforcement arrangement 16 includes a reinforcement member 24, which extends downwardly in use relative to the upper surface 26.

The reinforcement member 24 is generally aligned along a reinforcement axis 28. The reinforcement axis 28 extends through the centre of the load test area 22 when viewed in plan looking on the in use upper surface 26.

The reinforcement member 24 comprises a forked reinforcement member 30 which extends along a forked reinforcement member axis 32. The forked reinforcement member 30 includes an arm portion 34, in which the forked reinforcement member 30 comprises a single arm 36. In this example, the forked reinforcement member 30 comprises a pair of plural finger portions 38.

In the example shown, in each plural finger portion 38, the forked reinforcement member 30 comprises two fingers 40. The forked reinforcement member 30 includes two spaced fork junctions 42, at each of which the forked reinforcement member 30 changes from the arm portion 34 to the plural finger portion 38. It may be more convenient to describe the fork junctions as having “fork junction regions 42R”, with the location of the junction being at a notional point location 42N. The arm portion 34 is located between the fork junctions 42, with one plural finger portion 38 at or towards each end of the forked reinforcement member 30, at or towards an edge of the cover member 12.

Each of the fingers 40 extends transversely outwardly from the forked reinforcement member axis 32. In each plural finger portion 38, the fingers 40 extend outwardly on opposite sides of the forked reinforcement member axis

32. Each finger 40 extends outwardly at substantially the same angle 44 as the other to the forked reinforcement member axis 32. The fingers 40 are similar in size and shape and are substantially symmetrical about the forked reinforcement member axis 32.

The fingers 40 of each plural finger portion 38 diverge away from each other, moving away from the fork junction 42. The fingers 40 are curved when viewed in plan looking on the in use upper surface 26.

The plural finger portions 38 do not include a finger which extends along the forked reinforcement member axis 32.

In one example, the angle 44 could be no more than 60°, and could be no less than 15°. The angle 44 could change as the finger 40 curves and diverges away from forked member reinforcement axis 32, from a first angle 44A close to the forked member reinforcement axis 32 of between 15° and 30° and a second angle 44B close to the edge of the cover member 12 of between 40° and 60°.

In the example shown, the first angle 44A could be approximately 20° and the second angle 44B could be approximately 45°.

In the test condition, a test member 20 through which a test load is applied is located over the test load area 22, substantially centred on the central vertical axis 72. The test member 20 could comprise a plate and/or a pad.

The test load area 22 is located over the arm portion 34 and between the fork junctions 42 when viewed in plan looking on the in use upper surface

26.

The forked reinforcement member 32 is substantially symmetrical lengthwise about a central transverse axis 94 of the forked reinforcement member 32.

The cover member 12 is rectangular in shape and the seating surfaces 18 are located at each corner. The frame 14 includes cover mounting surfaces 48 at each corner, on which, in the assembled condition, the seating surfaces 18 of the cover member 12 locate and contact.

The cover member 12 includes auxiliary seating surfaces 46 and the frame 14 includes auxiliary cover mounting surfaces 50, located at the mid regions of the longer sides 110.

Each finger 40 comprises one of the auxiliary seating surfaces 46, located at or towards the edge of the cover member 12, one surface 46 being located at each end of each of the fingers 40.

In a relatively undeformed condition, (eg, when a load is not being applied to the upper surface 26), the auxiliary seating surfaces 46 do not contact the auxiliary cover mounting surfaces 50 of the support frame 14, and as shown in Fig. 7, a gap 68 is defined between each of the auxiliary seating surfaces 46 and the respective auxiliary cover mounting surface 50.

In a relatively deformed condition, (eg, when a load is being applied to the upper surface 26), the auxiliary seating surfaces 46 contact the auxiliary cover mounting surfaces 50 of the support frame 14 and transmit load therethrough.

The cover member 12 could include a plurality of bar members 66 which, together with the forked reinforcement member 30, form a grating, defining a plurality of grating openings 70. The bar members 66 could comprise part of the reinforcement arrangement 16.

In one example, the ground surface access assembly 10 is formed by a process including casting and is formed of a metal. Desirably, the ground surface access assembly 10 is formed of a ductile cast iron.

In use, the cover members 12 are located to the assembled condition on the frame 14, wherein the seating surfaces 18 of the cover member 12 are located on the cover mounting surfaces 48. With no load applied to the upper surface 26, the cover member 12 is in an undeformed condition and the auxiliary seating surfaces 46 are not in contact with the auxiliary cover mounting surfaces 50.

In performance testing in accordance with EN124, a test load is applied through the test member 20 which is in the form of a 250 mm diameter circular block, which is located on the test load area 22 on the upper surface 26. As the test load is applied, the cover member 12 deforms and the auxiliary seating surfaces 46 come into contact with the auxiliary cover mounting surfaces 50 to transmit load therethrough.

The performance testing shows that the forked reinforcement member 30 provides an improved load efficiency of the cover member 12 over conventional cover members.

The performance testing also shows that the provision of the auxiliary seating and cover mounting surfaces 46, 50 further improves the load efficiency of the cover member 12 over conventional cover members. In the example shown, advantageously, the forked reinforcement member 30 extends across a span between the auxiliary cover mounting surfaces 50 that is the shortest possible span through the central in use vertical axis 72 of the opening 74 for this assembly 10, so that in the loaded and deformed condition the forked reinforcement member 30 is operating at maximum efficiency, being as short as possible and being supported at each end, with a minimised length of span. The combination of the forked reinforcement member 30 and the auxiliary seating and cover mounting surfaces 46, 50 has surprisingly been found by the applicant to provide an improved load efficiency beyond that which would have been envisaged for the separate features.

In optimising the improvement in load efficiency over conventional arrangements, the applicant has found that the geometry of the reinforcement arrangement relative to the geometry of the mountings and the overall cover member is important.

In considering these geometries, it is convenient to separately consider the side profile geometry, as viewed from the side or in side cross section, and the plan geometry, as viewed in plan from above or below, although it should be realised that these geometries are, in practice, not separate and interact in three dimensions.

Considering the side profile geometry as shown in Figs. 5 to 7, the reinforcement member 24 has a central region 76 which is of substantially constant depth 100, which depth 100 is the maximum depth of the reinforcement member 24, measured from the upper surface 26. The central region 76 has a length 78 which might not be the same as, but could be substantially similar to, the length of the arm portion 34. On either side of the central region 76, a lower surface 106 curves convexly and upwardly to the respective auxiliary seating surface 46, at which the depth of the reinforcement member 24 is at a minimum.

In the assembled condition, the forked reinforcement member 30 extends over an unsupported length of span 98 between the auxiliary seats 46 along the reinforcement axis 16.

In one example, as shown in Figs. 1 to 7, the assembly 10 is of nominal opening size 430mm x 370mm. The central region length 78 could be at least 40% of the span length 98, and desirably could be at least 45% of the span length 98.

In the same example, the central region length 78 is approximately 220 mm and the span length 98 is approximately 340 mm. Thus, in this example, the central region length 78 is approximately 65% of the span length 98.

Considering the plan geometry and referring to Fig. 3, the arm portion 34 has a length 114, measured between the two fork junction notional point locations 42N. Each plural finger portion 38 has a length 116, measured from the respective fork junction notional point location 42N to the respective auxiliary seating surface 46.

In the example, the arm portion length 114 could be between 40% and 60% of the span length 98. In one example, each of the finger portion lengths 116 could be between 20% and 30% of the span length 98.

In the example, the arm portion length 114 could be approximately 186 mm and each finger portion length 116 could be approximately 75 mm. Thus, in this example, each of the finger portion lengths 116 is approximately 22% of the span length 98 and the arm portion length 114 is approximately 56% of the span length 98.

Figs 8 to 13 show another embodiment of the invention, many features of which are similar to those already described in relation to the embodiment of Figs 1 to 7. Therefore, for the sake of brevity, the following embodiment will only be described in so far as it differs from the embodiment already described. Where features are the same or similar, the same reference numerals have been used and the features will not be described again.

Figs. 8 to 13 show a second ground surface access assembly 210 comprising a pair of substantially triangular cover members 212 located, in an assembled condition, in a frame 214 defining a substantially square opening

74. Each cover member 212 has a longer side 120 and two shorter sides 122 and three seating surfaces 18, one at each corner, which in the assembled condition locate on cover mounting surfaces (not shown in Figs. 8 to 13) on the frame 214. The angle between the two shorter sides 122 is substantially 90°.

In the assembled condition, the cover members 212 are substantially centred around a central vertical axis 72 of the opening 74.

In this example, the cover members 212 are substantially identical.

Each cover member 212 includes one reinforcement member 24 in the form of a first reinforcement member 52 which is aligned along or parallel to a first reinforcement axis 54, which extends generally between two seating surfaces 18 and along or parallel to the longer side 120, and, in the assembled condition, substantially through the central vertical axis 72 of the opening 74 and between cover mounting surfaces on the frame 214.

In this example, the first reinforcement member 52 is symmetrical about an axis 108 which substantially bisects the angle between the two shorter sides 122.

The first reinforcement member 52 includes an inner central part 56. The inner central part 56 is substantially similar in length to the diameter of the load test area 22.

The first reinforcement member 52 includes a pair of outer central parts 58, one of which is located on either side of the inner central part 56, and which are relatively deep and relatively wide. The first reinforcement member 52 includes an inner junction 60 (having a region 60R and a notional point location 60N) where each outer central part 58 meets the respective inner central part 56.

The first reinforcement member 52 includes end parts 62, one of which is located at or towards each end of the first reinforcement member 52, on the outer side of each outer central part 58. The first reinforcement member 52 includes an outer junction 84 where each outer central part 58 meets the respective end part 62. Each end part 62 is relatively shallow in depth and relatively wide.

Each end part 62 reduces in depth moving inwardly, to a depth minimum 92 at the respective outer junction 84.

The first reinforcement member 52 includes bracing members 88 which extend inwardly from the inner central part 56 towards each other and the central vertical axis 72 of the opening 74 in the assembled condition. The bracing members 88 include bracing surfaces 86, which slope inwardly towards each other and upwardly towards the upper surface 26. Each bracing member 88 includes a substantially planar abutment surface 126. The abutment surfaces 88 are substantially coplanar, are substantially in an in use vertical plane, and are continuous with and coplanar with an edge surface 128 of the cover member 212 which extends along the longer side 120 of the cover member 212.

In broad terms, considering the side profile geometry of the first reinforcement member 52 in Figs. 11 and 12, and moving outwardly from the central vertical axis 72, the first reinforcement member 52 includes a central deepest region 76 of constant depth 100, at which the depth of the first reinforcement member 52 is at a maximum, a reducing region 124 having a convexly curved surface which reduces in depth to the minimum 92 at the outer junction 84 (whereat the surface is concave), and the end part 62 which has a convexly curved surface which increases in depth to a local maximum substantially at the respective seating surface 18, which local maximum is less than the depth of the deepest central region 76.

The deepest region 76 has a half-length 77 measured outwardly from the central vertical axis 72 along the first reinforcement member 52. Each convex reducing region 124 has a length 125 measured along the first reinforcement member 52. Each end part 62 has a length 63 measured along the first reinforcement member 52. The minimum depth 92 is at a horizontal distance 96 from the central vertical axis 72, and has a depth dimension 102 measured from the upper surface 26. Each respective seating 18 at each end of the longer side 120 is an unsupported span half-length 99 from the central vertical axis 72. The dimensions in this paragraph are all as measured along the first reinforcement axis 54.

In this specification, the term “half-length” is used to denote a dimension which is measured to the central vertical axis 72 of the opening, as this is half of the full span length. The first reinforcement axis 54 passes through the central vertical axis 72.

In one example, the deepest region half-length 77 is at least 40% of the unsupported span half-length 99, and may be no more than 60% of the unsupported span half-length 99. Optimally the deepest region half-length 77 is between 45% and 55% of the unsupported span half-length 99.

In one example, each convex reducing region length 125 is at least 20% ofthe unsupported span half-length 99, and may be less than 30% of the unsupported span half-length 99.

In one example, each end part length 63 is at least 20% of the unsupported span half-length 99, and may be less than 30% of the unsupported span half-length 99.

Each convex reducing region length 125 could be similar to each of the end part lengths 63.

In one example, the minimum depth horizontal distance 96 from the central vertical axis 72 is at least 60% and desirably at least 70% of the unsupported span half-length 99, and may be less than 90%, and desirably less than 80%, ofthe unsupported span half-length 99.

In one example, the depth 102 at the minimum 92 could be no more than 50% ofthe maximum depth 100.

In one example, as shown in Figs. 8 to 13, the cover member 212 could have shorter sides 122 of length approximately 596mm and the first reinforcement member 52 could have the dimensions given in Table 1. In this example, the overall depth of the frame 214 could be 100mm and the maximum depth 100 of the cover member 212 at the deepest region 76 measured from the upper surface 26 could be 90mm. In another example, the overall depth of the frame 214 could be 150mm and the maximum depth 100 of the cover member 212 at the deepest region 76 measured from the upper surface 26 could be 140mm.

Part	Measurement mm	Proportion of Unsupported Span Half-Length 99 %
Deepest region half-length 77	237.5	50.2
Convex reducing region length 125	110	23.3
End part length 63	127.5	27.0
Minimum depth horizontal distance 96	347.5	73.5
Unsupported span half-length 99	472.5	100

Table 1: Example of Side Profile Part Dimensions for

First Reinforcement Member 52

In one example, the depth 102 at the minimum 92 could be 30mm, 35% of the maximum depth 100.

Looking in plan from below, as shown in Figs. 9 and 14, and moving outwardly from the central vertical axis 72 and the second reinforcement axis 82, the first reinforcement member 52 is relatively narrow in width in the inner central part 56, has a first local maximum width at the inner junction region 60R, narrows to a first local minimum width 134 at or just beyond an outer edge 136 of the deepest central region 76, widens to a second local maximum width 132 just before the outer junction 84, narrows to a second local minimum width 138 just beyond the outer junction 84 (which second minimum is greater than the first minimum), widens to a third local maximum width 140 and narrows again towards the respective seating surface 18.

The changes in width are smooth and curved, so that the appearance of the first reinforcement member 52 in plan is somewhat organic in form, reminiscent of a twig or a bough of a tree. The sequential narrowing and broadening could be described as a succession of rounded bulges or swellings.

The applicant has surprisingly found that the sequential narrowing and broadening of the width of the first reinforcement member 52 does not correspond exactly with the changes in depth of the first reinforcement member 52. Again, surprisingly, in general terms, the deepest central region 76 is narrower on average than the convex reducing regions 124 or the end parts 62.

The first reinforcement member 52 therefore at least varies in width along its length, and could have at least one minimum width and one maximum width, and desirably could have a plurality of local minimum widths and a plurality of local maximum widths, which are arranged sequentially.

When viewed in plan from below, the first reinforcement member 52 includes a pair of curved members 142, each of which extends from a different one of the respective seating surfaces 18 in a concave arc relative to the first reinforcement axis, to the edge surface 128 at a different one of the abutment surfaces 126, close to the central vertical axis 72. Each curved member 142 includes one of the end parts 62, the respective adjacent outer central part 58, and the respective bracing member 88.

The reinforcement arrangement 16 includes another reinforcement member 24 which comprises a second reinforcement member 80 which is aligned along or parallel to a second reinforcement axis 82. The second reinforcement axis 82 is orientated at substantially 90° to the first reinforcement axis 54, and extends from one of the seating surfaces 18 substantially towards and through the central vertical axis 72.

The second reinforcement member 80 is in the form of a forked reinforcement member, with similar features to those of the forked reinforcement member 30 described in relation to the previous embodiment. The second reinforcement member 80 is double ended with a central arm portion 34 and a plural finger portion 38 each with two fingers 40 at each end, one plural finger portion 38 being an inner plural finger portion 38i with inner fingers 40i and the other an outer plural finger portion 38o with outer fingers 40o. In this embodiment, the second reinforcement member 80 is asymmetrical lengthwise.

Each inner finger 40i of the inner plural finger portion 38i extends from an inner fork junction 42i (having a region 42iR and a notional point location 42iN) to meet the first reinforcement member 52 at or in the vicinity of the inner junction 60. Each inner finger 40i is curved (in plan view) and increasingly diverges from the other moving away from the inner fork junction 42i.

The angle 44i of each of the inner fingers 40i to the second reinforcement axis 82 could be no more than 60°, and could be no less than 15°. The inner finger angle 44 could change as the inner finger 40A curves and diverges away from the second reinforcement axis 82, from an inner finger first angle 44iA close to the second reinforcement axis 82 of between 15° and 30° and an inner finger second angle 44iB away from second reinforcement axis 82 of between 40° and 60°.

In the example shown, the inner finger first angle 44iA could be approximately 24° and the inner finger second angle 44iB could be approximately 53°.

Each outer finger 40o of the outer plural finger portion 38o extends from an outer fork junction 42o (having a region 42oR and a notional point location 42oN) towards a same one of the seating surfaces 18A at the corner of the cover member 212. Each outer finger 40o initially extends at an angle

44oA to the second reinforcement axis 82 of no more than 60°, and no less than 15°, but here the outer fingers 40o then curve around and extend substantially parallel to each other and spaced apart towards the respective same seating surface 18A.

In the example shown, the outer finger first angle 44oA could be approximately 27°.

The inner fingers 40i, the arm 36 and the outer fingers 40o are each similarly relatively narrow in width, and are similar in width to the inner central part 56 of the first reinforcement member 52.

The inner fingers 40A and an inner part of the arm 36 are relatively deep and are similar in depth to the inner central part 56 of the first reinforcement member 52, having a depth dimension 100.

Considering the plan geometry and referring to Fig. 13, the arm portion 34 has a length 114, the inner plural finger portion 38i has a length 116i and the outer plural finger portion 38o has a length 116o, these lengths being measured along or parallel to the second reinforcement axis 82. The inner plural finger portion length 38i is measured to the inner junction notional point location 60N of the first reinforcement member 52. The second reinforcement member 80 has an unsupported second reinforcement member length 144 which is measured to the inner junction notional point location 60N along or parallel to the second reinforcement axis 82.

Examples of these dimensions are given below in Table 2, which relate to the cover member 212 as shown in Figs. 8 to 13 which has shorter sides 122 of length approximately 596mm. In Table 2, the proportions are given relative to the unsupported second reinforcement member length 144.

Thus, referring to Table 2, the proportions of the arm portion length 114, the inner finger portion length 116i and the outer finger portion length

116o are roughly equal, being 33.3 % ± 4% as a proportion of the unsupported second reinforcement member length 144.

Part	Approximate Measurement mm	Proportion of Unsupported Second Reinforcement Member Length 144 %
Arm portion length 114	132.5	31.1
Inner finger portion length 116i	137.5	32.3
Outer finger portion length 116o	155	36.4
Unsupported second reinforcement member length 144	425	100

Table 2: Example of Part Dimensions for

Second Reinforcement Member 80 Relative to Unsupported Second

Reinforcement Member Length 144

Considering the side profile geometry of the second reinforcement member 80 as shown in Fig. 13 and moving outwardly from the central vertical axis 72, the second reinforcement member 80 includes an innermost deepest region 76A of constant depth 100, at which the depth of the second reinforcement member 80 is at a maximum, a reducing region 124A having a convexly curved surface which reduces in depth to a depth minimum 92A (whereat the surface is concave) at an outer junction 84A and an end part 62A which has a convexly curved surface which increases in depth to a local maximum substantially at the respective seating surface 18A, which local maximum is less than the depth of the deepest central region 76A.

The innermost deepest region 76A is substantially the same depth as the central deepest region 76 of the first reinforcement member 52.

The deepest region 76A has a half-length 77A measured outwardly from the central vertical axis 72. The convex reducing region 124A has a length 125A in the horizontal plane. The end part 62A has a length 63A in the horizontal plane. The minimum depth 92A is at a horizontal distance 96A from the central vertical axis 72. The respective seating surface 18A is an unsupported span half-length 99A from the central vertical axis 72.

In one example, the deepest region half-length 77A could be at least 40% of the unsupported span half-length 99A, and could be less than 60% of the unsupported span half-length 99A. Optimally the deepest region halflength 77A could be between 45% and 55% of the unsupported span halflength 99A.

In one example, each convex reducing region length 125A could be at least 20% of the unsupported span half-length 99A, and could be less than 30% of the unsupported span half-length 99A.

In one example, each end part length 63A could be at least 20% of the unsupported span half-length 99A, and could be less than 30% of the unsupported span half-length 99A.

Each convex reducing region length 125A could be similar to each of the end part lengths 63A.

In one example, the minimum depth horizontal distance 96A could be at least 70% of the unsupported span half-length 99A, and could be less than 80% of the unsupported span half-length 99A.

In one example, the depth 102A at the minimum 92 could be no more than 50% ofthe maximum depth 100.

In one example, the cover member 212 could have a shorter side 122 of length approximately 596mm and the second reinforcement member 80 could have the dimensions given in Table 3:

Part	Measurement mm	Proportion of Unsupported Span Half-Length 99A %
Deepest region half-length 77A	250	51.5
Convex reducing region length 125A	112.5	23.2
End part length 63A	120	24.7
Minimum depth horizontal distance 96A	365	75.2
Unsupported span half-length 99A	485	100

Table 3: Example of Side Profile Part Dimensions for

Second Reinforcement Member 80

In one example, the depth 102A at the minimum 92A could be 26mm,

30.4% of the maximum depth 100.

It is of particular interest and significance to note the similarities in the dimensions and proportions of the side profiles of the first reinforcement member 52 and the second reinforcement member 80 given in Tables 1 and

3. In both cases, the deepest region half-lengths 77, 77A are a similar distance away from the central vertical axis 72 (245mm ± 10mm), the minimum depth horizontal distances 96, 96A are similar (356mm ± 10mm) and the proportions of the deepest region half-lengths 77, 77A, the convex reducing region lengths 125, 125A, the end part lengths 63, 63A and the minimum depth horizontal distances 96, 96A are similar each case, dividing up, roughly and respectively, as 50%, 25%, 25%, 75% within a tolerance of ± 2%.

Part of one of the reinforcement members 24 comprises a test area perimeter reinforcement arrangement 64, which substantially corresponds in shape and location with at least part of a perimeter of the test load area 22 when viewed in plan. The test area perimeter reinforcement arrangement 64 includes two of the fingers 40i of the inner plural finger portion 38i and the inner junctions 60 of the first reinforcement member 52.

The ground surface access assembly 201 includes a pair of cover members 212, which are substantially similar, so that, in the assembled condition, the test area perimeter reinforcement arrangements 64 of the two covers 212 correspond in shape and location with substantially a major proportion of the perimeter of the test load area 22 when viewed in plan.

The reinforcement arrangement 16 could include other reinforcement features. In the example shown, the reinforcement arrangement 16 includes a lifting key chamber wall 90, which defines a chamber (not shown) for receiving a lifting key (not shown) during lifting. The first reinforcement member 52 defines a pair of spaced fastening holes 148, for receiving fasteners (not shown) to loosely fasten the cover members 212 together in the assembled condition.

In use, the cover members 212 are located to the assembled condition on the frame 214, wherein the seating surfaces 18 of the cover members 212 are located on the cover mounting surfaces (not shown).

In performance testing in accordance with EN124, a test load is applied through the test member 20 which is in the form of a 250 mm diameter circular block, which is located on the test load area 22 on the upper surface 26. A deformable layer (not shown) of a material such as paper, timber or rubber is located between the test member 20 and the upper surface 26 to avoid point loading through relatively minor surface features such as cast-in identification wording or grip features. As the test load is applied, the cover members 212 deform. The test specification sets a limit to the “permanent deformation” which results when the appropriate test load has been applied and then removed.

In testing, the ground surface access assembly 210 has been found to have significantly improved load efficiency over conventional arrangements.

The distinctive and significant features of the reinforcement arrangement 16 of this embodiment are thought to be as follows. These are not necessarily listed in order of significance.

1. The same constant maximum depth of the central deepest regions 76, 76A, which extends outwardly from the central vertical axis 72 for substantially the same distance along the first and second reinforcement axes 54, 80. This provides a stable base for stacking the cover members. The depth dimension 100 is selected so that, when stacking assemblies, contact between adjacent assemblies in a vertical stack is between adjacent frames, with no contact between cover members of adjacent assemblies. Hence, the depth 100 is less than the frame depth by a clearance amount, eg 15mm.

2. The minimum depths 92, 92A of the first and second reinforcement members 52, 80 at approximately the same distance along the first and second reinforcement axes 54, 80, at around 75% of the unsupported span half4ength.

3. The double ended forked reinforcement member 80.

4. The bracing parts 88 and the abutment surfaces 126.

5. The organic, bowed sequential broadening and narrowing of the width of the first reinforcement member 52.

6. The curved reinforcement members 142.

7. The test area perimeter reinforcement arrangements 64.

At present, the individual significance of each of these features is not known and further work is being undertaken to assess this.

One possible theory to explain why these features provide such a significant improvement in load efficiency is that the constant depth of the central deepest regions 76, 76A provides a relatively stiff central support below the test area 22 which transmits and dissipates the load laterally outwardly along the reinforcement members 52, 80. The minimum depths 92, 92A provide a degree of “springiness” which permits temporary deformation outward of the load area and further absorb and dissipate the load.

In another possible theory, as the cover members 212 deform under load, the abutment surfaces 126 of the adjacent cover members 212 move into contact with each other, “locking” the adjacent cover members 212 together to improve the stiffness of the central support below the load test area 22 and the outward dissipation of the load.

Various other modifications could be made without departing from the scope of the invention. The cover members, the frames and the ground surface access assemblies could be of any suitable size and shape, and could be formed of any suitable material (within the scope of the specific definitions herein). For example, the cover members could be circular, square, rectangular or triangular in plan shape. Any convenient number of cover members could be mounted in a frame.

In one modification of the first embodiment, the ends of the fingers 40 are joined together (for example, by a cross member) to provide a single seating surface.

Any of the features or steps of any of the embodiments shown or described could be combined in any suitable way, within the scope of the overall disclosure of this document.

There is thus provided ground surface access assemblies with a number of advantages over conventional arrangements. In particular, the reinforcement arrangements disclosed provide improved load efficiency, which results in less material being required to meet the performance standard, resulting in lower manufacturing and transport costs and therefore reduced environmental impact.

Claims

1. A ground surface access assembly, the assembly including a cover member, the cover member including a reinforcement arrangement and

5 one or more seating surfaces which, in an assembled condition, contact a support frame and transmit load therethrough, the reinforcement arrangement being arranged, in a test condition, to transmit load applied to a load test area on an in use upper surface of the cover member through the seating surface(s).

2. An assembly according to claim 1, in which the reinforcement arrangement includes one or more reinforcement members.

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3. An assembly according to claim 2, in which the one or more reinforcement members extend downwardly in use relative to the upper surface.

4. An assembly according to claims 2 or 3, in which the or each reinforcement member is generally aligned along a reinforcement axis, which extends through the load test area when viewed in plan looking on the in use upper surface.

5. An assembly according to any of claims 2 to 4, in which the or one reinforcement member comprises a forked reinforcement member which extends along a forked reinforcement member axis, the forked

25 reinforcement member including:

• an arm portion, in which the forked reinforcement member comprises a single arm:

• a plural finger portion, in which the forked reinforcement member comprises a plurality of fingers; and

30 «a fork junction at which the forked reinforcement member changes from the arm portion to the plural finger portion.

6. An assembly according to claim 5, in which the plural finger portion comprises two fingers, each of which extend transversely outwardly from the forked reinforcement member axis.

5

7. An assembly according to claim 6, in which the fingers extend outwardly on opposite sides of the forked reinforcement member axis.

8. An assembly according to claim 7, in which each finger extends outwardly at an angle to the forked reinforcement member axis.

9. An assembly according to claim 8, in which each finger extends outwardly at substantially the same angle as the other to the forked reinforcement member axis.

i— 15 10. An assembly according to claims 8 or 9, in which the angle is no more

CO than 60°, and may be no less than 5°.

o co 11. An assembly according to any of claims 6 to 10, in which the fingers are ¹ similar in size and shape.

12. An assembly according to any of claims 6 to 11, in which the fingers are substantially symmetrical about the forked reinforcement member axis.

13. An assembly according to any of claims 6 to 12, in which the fingers 25 diverge away from each other, moving away from the fork junction.

14. An assembly according to any of claims 6 to 13, in which the fingers are curved when viewed in plan looking on the in use upper surface.

30 15. An assembly according to any of claims 5 to 14, in which the finger portion does not include a finger which extends along the forked reinforcement member axis.

16. An assembly according to any of claims 5 to 15, in which the finger portion is located at or towards an edge of the cover member.

17.An assembly according to any of claims 5 to comprises one of the seating surfaces.

16, in which each finger

18. An assembly according to any of claims 5 to 17, in which, in the test condition, the test load area is located over the arm portion when viewed in plan looking on the in use upper surface.

19. An assembly according to any of claims 5 to 18, in which the forked reinforcement member includes two fork junctions, and the arm portion is located between the fork junctions, with one plural finger portion at or towards each end of the forked reinforcement member.

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20. An assembly according to claim 19, in which in the test condition, the test load area is located between the fork junctions when viewed in plan looking on the in use upper surface.

20 21.An assembly according to any of claims 5 to 20, in which the forked reinforcement member is substantially symmetrical lengthwise about a central point of the forked reinforcement member.

22. An assembly according to any of the preceding claims, in which the cover 25 member Includes one or more auxiliary seating surfaces which, In a deformed condition, contact the support frame and transmit load therethrough, but In an undeformed condition do not contact the support frame.

30 23. An assembly according to claim 22, in which, in the undeformed condition, a gap is defined between each of the auxiliary seating surfaces and the support frame.

24. An assembly according to claims 22 or 23 when dependent on claim 17 or any claim dependent thereon, in which each finger seating surface comprises one of the auxiliary seating surfaces.

5 25. An assembly according to claim 17 or any claim dependent thereon, in which each finger seating surface is located at or below an end of the respective finger.

26. An assembly according to claim 2 or any claim dependent thereon, in

10 which the or one reinforcement member Includes a depth minimum, where the depth of the respective reinforcement member is at a minimum, which minimum is not located at an end of the reinforcement member.

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27. An assembly according to claim 26, in which the depth minimum is located at a distance of no less than 10%, and desirably no less than 20% as a proportion of the unsupported span half-length of the respective reinforcement member, as measured from the seating surface towards an in use central vertical axis of an opening in which the cover member is located.

28. An assembly according to claims 26 or 27, in which the depth minimum is located at a distance of no more than 40%, and desirably no more than 30% as a proportion of the unsupported span half-length of the respective reinforcement member, as measured from the seating surface towards an in use central vertical axis of an opening in which the cover member is located.

29. An assembly according to claim 2 or any claim dependent thereon, in which the or one reinforcement member Includes a constant depth region,

30 in which region the depth of the respective reinforcement member Is substantially constant.

30. An assembly according to claim 29, in which, in the constant depth region, the depth of the respective reinforcement member is at a maximum.

31. An assembly according to claims 29 or 30, in which the constant depth 5 region extends over a central region of the respective reinforcement member.

32. An assembly according to any of claims 29 to 31, in which the constant depth region extends over a distance of at least 40% and possibly no more

10 than 60%, and desirably at least 45% and possibly no more than 55%, of the unsupported span half-length of the respective reinforcement member, as measured from the central vertical axis towards the seating surface co o

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33. An assembly according to claim 2 or any claim dependent thereon, In which the or one reinforcement member comprises a first reinforcement member which is aligned along or parallel to a first reinforcement axis.

34. An assembly according to claim 33, in which the first reinforcement member includes an inner central part which is relatively deep.

35. An assembly according to claims 33 or 34, in which the first reinforcement member includes an inner central part which is relatively narrow in width.

36. An assembly according to claims 34 or 35, in which the inner central part 25 is substantially similar in length to the diameter of the load test area.

37. An assembly according to any of claims 34 to 36, in which the first reinforcement member includes outer central parts, one of which is located on either side of the inner central part.

38. An assembly according to claim 37, in which the outer central parts are relatively deep.

39. An assembly according to claim 37 or 38, in which the outer central parts are relatively wide.

40. An assembly according to any of claims 37 to 39, in which the first 5 reinforcement member includes inner junctions where each outer central part meets the inner central part.

41. An assembly according to any of claims 37 to 40, in which the first reinforcement member includes end parts, one of which is located at or

10 towards each end of the first reinforcement member, on the outer side of each outer central part.

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42. An assembly according to claim 41, in which the first reinforcement member includes outer junctions where each outer central part meets the respective end part.

43. An assembly according to claims 41 or 42, in which each end part is relatively shallow in depth.

20 44. An assembly according to any of claims 41 to 43, in which each end part is relatively wide.

45. An assembly according to any of claims 41 to 44, in which each end part reduces in depth moving inwardly.

46. An assembly according to claim 42 or any claim dependent thereon, in which each end part substantially reduces to a minimum at the outer junction.

30 47. An assembly according to claim 42 or any claim dependent thereon, when dependent on claim 26 or any claim dependent thereon, in which the depth minimum is located at the outer junction.

48.An assembly according to any of claims 33 to 47, in which the first reinforcement member includes bracing surfaces, which slope inwardly and upwardly towards the upper surface.

5 49.An assembly according to any of claims 33 to 48, in which the first reinforcement axis extends between two of the seating surfaces.

50.An assembly according to any of claims 33 to 49, in which another reinforcement member comprises a second reinforcement member which

10 is aligned along or parallel to a second reinforcement axis.

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51. An assembly according to claim 50, in which the second reinforcement axis is orientated at substantially 90° to the first reinforcement axis.

52. An assembly according to claims 50 or 51, in which the second reinforcement axis extends from one of the seating surfaces, substantially towards a central point of the test load area.

53. An assembly according to any of claims 50 to 52, in which the second reinforcement member comprises a forked reinforcement member.

54. An assembly according to any of claims 50 to 53, in which the second reinforcement member is asymmetrical lengthwise.

25 55. An assembly according to any of claims 50 to 54, in which the second reinforcement member includes an inner plural finger portion, in which each finger of the inner plural finger portion extends to meet the first reinforcement member.

30 56. An assembly according to claim 55 when dependent on claim 40 or any claim dependent thereon, in which each finger of the inner plural finger portion extends to meet the first reinforcement member at or in the vicinity of the inner junction.

57. An assembly according to any of claims 50 to 56, in which the second reinforcement member includes an outer plural finger portion, which is located at or towards an edge, or a corner, of the cover member and the

5 one of the seating surfaces is located at or towards the ends of the fingers ofthe outer plural portion.

58. An assembly according to claim 57 when dependent on claims 55 or 56, in which the second reinforcement member includes an arm portion located

10 between the inner plural finger portion and the outer plural finger portion.

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59. An assembly according to claim 55 or any claim dependent thereon, in which the inner finger portion of the second reinforcement member is relatively deep.

60. An assembly according to claims 55 or any claim dependent thereon, in which the inner finger portion of the second reinforcement member is relatively narrow in width.

20 61 .An assembly according to claim 55 or any claim dependent thereon, when dependent on claim 35 or any claim dependent thereon, in which the inner finger portion of the second reinforcement member is similar in depth and width to the inner central part of the first reinforcement member.

25 62. An assembly according to claim 2 or any claim dependent thereon, in which part of the or one or some reinforcement members comprise a test load perimeter reinforcement arrangement, which extends around at least part of a perimeter of the test load area when viewed in plan looking on the in use upper surface.

63. An assembly according to claim 62 when dependent on claim 55 or any claim dependent thereon, in which the test load perimeter reinforcement arrangement includes two of the fingers of the inner plural finger portion.

64. An assembly according to claim 63, in which the two fingers of the inner plural finger portion are orientated substantially at 90° to each other.

5 65. An assembly according to claim 33 or any claim dependent thereon when dependent on claim 26 or any claim dependent thereon, in which the first reinforcement member includes a pair of the aforesaid depth minima, spaced apart, which minima are not located at the ends of the first reinforcement member.

66. An assembly according to claim 50 or any claim dependent thereon, when dependent on claim 26 or any claim dependent thereon, in which the second reinforcement member includes the aforesaid depth minimum, which minimum may not be located at the end of the second reinforcement i— 15 member.

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67. An assembly according to claim 50 or any claim dependent thereon, when

CO dependent on claim 33 or any claim dependent thereon, in which each of ¹ the first and second reinforcement members includes a constant depth

20 region, in which region the depth of the respective reinforcement member is substantially constant and at a maximum.

68. An assembly according to claim 67, in which the constant depth region extends over a central region of the first reinforcement member.

69. An assembly according to claims 67 or 68, in which the constant depth region extends over an innermost region of the second reinforcement member.

30 70. An assembly according to any of the preceding claims, in which the ground surface access assembly includes a pair of cover members.

71.An assembly according to claim 70, in which the cover members are substantially similar.

72. An assembly according to claim 71 when dependent on claim 62 or any 5 claim dependent thereon, in which, in an assembled condition, the test load perimeter reinforcement arrangements of the two covers extend substantially wholly or around a greater part of the test load area when viewed in plan looking on the in use upper surface.

10 73. An assembly according to any of the preceding claims, in which the ground surface access assembly includes a frame, which defines an opening, in which one or more of the cover members locates in use.

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74. An assembly according to any of the preceding claims, in which the ground surface access assembly is formed by a process including casting and may be formed of a metal and may be formed of a cast iron, and may be formed of a ductile cast iron.

75. An assembly according to any of the preceding claims, in which the ground surface access assembly is arranged to comply with European Standard EN124.

76. A method of providing access to an underground service, the method including providing a ground surface access assembly, the assembly

25 including a cover member, the cover member including a reinforcement arrangement and one or more seating surfaces which, in an assembled condition, contact a support frame and transmit load therethrough, the reinforcement arrangement being arranged, in a test condition, to transmit load applied to a load test area on an in use upper surface of the cover

30 member through the seating surface(s).

77. A method according to claim 76, in which the assembly includes any of the features defined in any of claims 1 to 75.

Intellectual

Property

Office

Application No: GB 1604263.2 Examiner: Dr Louis Emery