GB2311550A

GB2311550A - Device for mounting an access cover

Info

Publication number: GB2311550A
Application number: GB9606746A
Authority: GB
Inventors: David John Drake Hawkins
Original assignee: CSR Ltd
Current assignee: CSR Ltd
Priority date: 1996-03-29
Filing date: 1996-03-29
Publication date: 1997-10-01
Also published as: AU727064B2; ZA972773B; CA2250370A1; EP0890001A1; NZ332095A; ATE210228T1; IL126387A; DE69708854D1; IL126387A0; GB9606746D0; EP0890001B1; AU2298697A; WO1997037086A1; DE69708854T2

Abstract

The present invention relates to a device for mounting an access cover (60) in a wearing surface, for example a road surface, having a wear course (7) overlying a base course (8), the device comprising a service frame (50) in which the cover is removably received and a main frame (20) for mounting below the base course, wherein the service frame is movable to a plurality of positions relative to the main frame including a first position at which, in use, a top surface (62) of the access cover is substantially flush with the top surface (11) of the wearing course and a second position at which, in use, the top surface of the access cover is substantially flush with the bottom surface of the base course. A method of resurfacing a road or the like is also provided.

Description

DEVICE FOR MOUNTING AN ACCESS COVER The present invention relates to a device for mounting an access cover, such as a manhole cover, in a wearing surface.

For the avoidance of doubt by the term wearing surface is meant any surface, such as roads and pavements, which require periodic resurfacing.

Access covers are a common feature of road and pavement surfaces and provide access to underground services and installations, such as sewage, telephone, electrical, gas and water installations. The access cover generally resides in a supporting frame which is formed from cast iron and extends down into the foundations beneath the road or pavement and may be set therein with concrete or a similar material.

The level at which the frame is set into the foundation is chosen such that, with the access cover residing in the frame, the upper surface of the access cover lies substantially flush with the road surface.

Due to wear from traffic, road and pavement surfaces require periodic resurfacing.

Resurfacing of the wearing surface may be effected either by planing down the original surface followed by laying a new surface at substantially the same level as the original surface or by simple laying a new surface on the existing surface.

In the former case the cutting gear of the planing apparatus may collide with the upper part of the support frame, damaging both the cutting gear and the support frame. It will be appreciated that it is also difficult to work around the protruding parts.

Furthermore, once the road or pavement surface has been planed, parts of the supporting frame which stand proud of the surface pose a major safety hazard to traffic. In the latter case, in order to raise the access cover to the level of the new road or pavement surface, the support frame needs to be dug up and reset at the new higher level. This is clearly time consuming and expensive.

Accordingly, the present invention provides a device for mounting an access cover in a wearing surface, for example a road surface, having a wear course overlying a base course, the device comprising a service frame in which the cover is removably received and a main frame for mounting below the base course, wherein the service frame is movable to a plurality of positions relative to the main frame including a first position at which a top surface of the access cover is substantially flush with the top surface of the wearing course and a second position at which the top surface of the access cover is substantially flush with the bottom surface of the base course.

Preferably the service frame is supported on the main frame by support means. The support means are preferably adjustable and/or removable. In this case, adjustment and/or removal of the support means enables the service frame to be moved relative to the main frame to a plurality of positions including the first and second positions.

In a preferred embodiment of the present invention there is provided a device for mounting an access cover in a wearing surface, for example a road surface, having a wear course overlying a base course, the device comprising a service frame in which the cover is removably received, a main frame for mounting below the base course, and support means to support the service frame on the main frame at a first position at which a top surface of the access cover is substantially flush with the top surface of the wearing course, wherein removal and/or adjustment of the support means enables the service frame to be moved relative to the main frame to a second position at which the top surface of the access cover is substantially flush with the bottom surface of the base course.

The service frame is preferably an open annular or rectangular frame having at a base thereof an outwardly extending flange. The access cover is preferably removably received in the service frame, but may also be hingedly connected thereto.

The main frame is preferably an open annular or rectangular frame having at a base thereof an inwardly extending flange. Advantageously the main frame surrounds the service frame at the second position.

Preferably the support means comprises one or more collars, preferably disposed between an upper surface of the flange of the main frame and a lower surface of the flange of the service frame. The one or more collars may comprise separable segments.

The support means preferably further comprises a height-adjustable spacer element. In this case, the height-adjustable spacer element preferably comprises a collar and wedge arrangement, a collar having one or more adjustable screws running therethrough, or one or more hydraulic jacks or rams or a combination thereof.

The device according to the present invention may further comprise one or more extension collars located on a top portion of the main frame and/or one or more spacer elements located on a top portion of the service frame.

The present invention also provides for a method of resurfacing a wearing surface having a wear course overlying a base course, wherein a device as herein described is sited in the wearing surface, the method comprising the steps of: (a) moving the service frame to the second position; (b) planing down the wear and base courses to the desired depth; (c) moving the service frame relative to the main frame to a position such that the top surface of the access cover will be substantially flush with the top surface of the base course to be laid; (d) laying the base course; (e) moving the service frame such that it will be at substantially the first position when the wear course is laid; and (f) laying the wear course.

In an alternative embodiment, the present invention provides a method of laying a new wear surface on a wearing surface having a wear course overlying a base course, wherein a device as herein described is sited in the wearing surface, the method comprising the steps of: (a) moving the service frame to a level at which the top surface of the access cover will be substantially flush with the top surface of the new wear course to be laid; and (b) laying the wear course.

The present invention also provides for a method of resurfacing a wearing surface having a wear course overlying a base course, wherein a device as herein described and comprising support means is sited in the wearing surface, the method comprising the steps of: (a) adjusting and/or removing the support means such that the service frame is in the second position; (b) planing down the wear and base courses to the desired depth; (c) adjusting and/or reinserting the support means such that the top surface of the access cover will be substantially flush with the top surface of the base course to be laid; (d) laying the base course; (e) adjusting the support means such that the service frame will be at substantially the first position when the wear course is laid; and (f) laying the wear course.

In an alternative embodiment, the present invention also provides for a method of laying a new wear surface on a wearing surface having a wear course overlying a base course, wherein a device as herein described and comprising support means is sited in the wearing surface, the method comprising the steps of: (a) adjusting the support means to raise the service frame to a level at which the top surface of the access cover will be substantially flush with the top surface of the new wear course to be laid; and (b) laying the wear course.

The present invention will now be further described with reference to the following drawings in which: Figure 1 is a schematic vertical cross-sectional half view of a device according to the present invention; Figure 2 is a plan view of a collar of the height-adjustable spacer element of the support means; Figure 3 is a vertical cross-section through line AA' of the plan view illustrated in Figure 2 showing tapered recesses in the collar of the heightadjustable spacer element; Figure 4 is a plan view of an alternative base collar of the support means; and Figure 5 is a vertical cross-sectional illustration of a main frame for use with the base collar of Figure 4.

In Figure 1, a device 1 according to the present invention is shown sited in a road 5. The vertical cross-sectional view shows one half of the device 1 and the other half is simply a mirror image of this half about the dashed centre line of the access hole 15.

The device 1 comprises a main frame 20 formed from concrete and having an open rectangular form with an upwardly extending wall portion 21 and an inwardly extending flange portion 22 at its base. The main frame 20 has a squarish/rectangular horizontal crosssection (not shown) and the wall portion 21 thereof surrounds the access hole 15. A ridge 23 extends around the upper surface 24 of the wall portion 21 of the main frame 20 such that the outer top edge 25 is at a higher level than the inner top edge 26.

The main frame 20 sits on a service chamber 6 and the remainder of the road 5 consists of a wear course 7 (approximately 40mm depth) overlying a base course 8 (approximately 60mm depth), beneath which is a subbase course 9. It will be appreciated that the wear 7, base 8 and sub-base 9 courses may themselves each comprise a plurality of layers.

A first extension collar 30 is located on the upper surface 24 of the wall portion 21 of the main frame 20. The first extension collar 30 extends upwards from the sub-base course 9 to the top 10 of the base course 8 and has a similar horizontal crosssection (not shown) to that of the main frame 20. The first extension collar 30 is removably located on the main frame 20 by virtue of a ridge 31 provided around its base 32, which cooperates with the ridge 23 on the upper surface 24 of wall portion 21. A ridge 33 around the upper surface 34 of the first extension collar 30 is also provided.

Removably located on the upper surface 34 of the first extension collar 30 is a second extension collar 40, again of similar horizontal cross-section (not shown) to that of the main frame 20. The second extension collar 40 has a similar form to that of the first extension collar 30 and extends upwards from the base course 8 to a position adjacent to the top 11 of the wear course 7. The second extension collar 40 has a ridge 41 around its base 42 which cooperates with the ridge 33 on the upper surface 34 of the first extension collar 30. A ridge 43 around the upper surface 44 of the second extension collar 40 is also provided. Both the first 30 and second 40 extension collars are formed from concrete.

The main frame 20 and the two extension collars 30 and 40 surround a service frame 50, which is formed from cast iron and is an open rectangular frame having an upwardly extending wall portion 51 and outwardly and inwardly extending flange portions, 52 and 52a, respectively, at its base. Accordingly, the service frame 50 has an inverted T-section. The service frame 50 has a squarish horizontal cross-section (not shown) and the wall portion 51 thereof defines the access hole 15. The service frame 50 has a plurality of strengthening members 53 which join the outside surface 54 of the wall portion 51 to the upper surface 55 of the flange portion 52.

Removably received in the service frame 50 is an access cover 60 which comprises a horizontally extending cover portion 61 and a downwardly extending wall portion 63. The horizontal cross-section (not shown) of the cover portion 61 can take a variety of forms, such as circular or square, but is preferably tailored to suit the service frame 50. The base of the downwardly extending wall portion 63 rests on the upper surface 57 of flange portion 52a, and hence the access cover 60 is supported on the service frame 50.

The purpose of the access cover 60 is to prevent objects falling into the access hole 15. The cover portion 61 of the access cover 60 has a top surface 62 which is substantially flush with the top surface 11 of the wear course 7.

Support means 70 are positioned between the top surface 27 of the flange portion 22 of the main frame 20 and the bottom surface 58 of the flange portion 52 of the service frame 50. The support means 70 is removable and comprises a base collar 71 and a heightadjustable spacer element 80. The base collar 71 has a squarish horizontal cross-section (not shown) and a top surface 72. The aperture in the base collar 71 coincides substantially with the access hole 15. The base collar 71 is removably located in this position by means of sand grout 100. Positioned on top of the base collar 71 is the height-adjustable spacer element 80. This also comprises a collar 81 having a squarish horizontal cross-section (not shown) and an aperture coinciding substantially with that of the base collar 71. Around the upper surface 82 of collar 81, there are one or more tapered recesses, such as that shown at 85. One or more wedges are inserted into these recesses, such as the wedge shown at 86, whereby the taper of the wedge 86 cooperates with the taper of the recess 85. The tapered recess 85 and wedge 86 are shaped such that the top surface 87 of the wedge 86 remains substantially horizontal. Lateral movement of wedge 86 in the tapered recess 85 (and the lateral movement of the other wedges in the other tapered recesses which are not shown) enables the height of the service frame 50 to be carefully adjusted.

Furthermore, tilt can be catered for by laterally moving the wedges independently of one another. The bottom surface 58 of the flange portion 52 of the service frame 50 rests on the top surface 87 of the wedge 86 (and also on the top surfaces of the other wedges not shown). It will be appreciated that the service frame 50 may also be moved laterally within the main frame 20.

When the service frame 50 is at the desired height, that is when the top surface 62 of the cover portion 61 of the access cover 60 is substantially flush with the top surface 11 of the wear course 7, the service frame 50 is semi-permanently fixed in place by inserting grout, cement or other packing material in the gap between the bottom surface 58 of flange portion 52 and the top surface 82 of collar 81.

Once set, wedge 86 (and the other wedges not shown) can either be removed or left in place.

In Figure 2 a plan view of the collar 81 of the height-adjustable spacer element 80 is shown. The collar 81 has four walls 83a-d which define a central squarish aperture 84. In a region in the middle of the upper surface 82 of each of the four walls 83a-d, there are tapered recesses 85a-d, respectively. The recesses 85a-d extend from the outer edges 86a-d to the inner edges 87a-d of the four wall 83a-d, respectively.

Figure 3 is a vertical cross-section through line AA' showing the tapered recesses 85a and c in opposing walls 83a and c, respectively, and also the tapered recess 85d in wall 83d. The height of the tapered recesses at 83a and c decreases from the outer edges 86a and c to the inner edges 87a and c, respectively.

Figure 4 shows a plan view of a base collar 90 for use in an alternative embodiment of the removable support means 70. The base collar 90 in this embodiment of the present invention is similar to the collar illustrated in Figure 2, but with the tapered recesses removed, hence resulting in four equal and separate collar quarters 91a-d. When the collar quarters 91a-d are positioned as shown, they define a central squarish aperture 92 with regular gaps 93a-d between the collar quarters.

In Figure 5 a vertical cross-section of a main frame 20 for use with the base collar 90 of Figure 4 is shown. Four equally spaced raised sections, only three shown at 29a-c, are provided on the top surface 27 of the flange portion 22. The dimensions and positions of the raised sections 29a-c are such that they cooperate with the gaps 93a-d between the collar quarters of the base collar 90 shown in Figure 4.

Accordingly, the four collar quarters 91a-d are removably located on the top surface 27 of the flange portion 22 of the main frame 20. Jacks, such as of the hydraulic type or of the spring return ram variety, can now be positioned on the top surface of each of the three raised sections 29a-c (and also on the fourth raised section not shown) and flange portion 52 of the service frame 50 rested thereon.

The service frame 50 can then be raised or lowered to the desired level. With the jacks in place, grout, cement or other suitable packing material is inserted in the space between the bottom surface 58 of flange portion 52 and the top surfaces of the four collar quarters 91a-d. Once the grout or cement has set, the jacks may be removed. If the level needs to be changed again, all that is required is for the jacks to be reinserted into their former positions and for the service frame 50 to be jacked up during which process the grout or the cement is fractured and can be removed. Once at the desired new level, fresh cement or grout is inserted. As an alternative to using jacks to raise the service frame, pulling or lifting apparatus located above the service frame and releasably attached thereto may be used.

When the time comes to resurface the wearing surface, the following step are taken with reference to Figures 1 and 2. First, the support means 70 are removed, to allow the service frame 50 to be lowered down the access hole 15 and positioned on the top surface 27 of the flange portion 22 of the main frame 20. The service frame 50 and access cover 60 are consequently conveniently located under the road surface without disturbing the road. Next, the road 5 is planed down up to and including the base course 8.

In this process, the first 30 and second 40 extension collars are either removed or broken-up. The presence of the access cover 60 prevents objects and debris from falling down into the access hole 15.

Once the surface has been planed down to the depth required, the service frame 50 and access cover 60 are removed from the main frame 20 and the base collar 71 of the removable support means 70 is relocated on the top surface 27 of the flange 22 of the main frame 20.

The service frame 50 and access cover 60 are then placed back into the main frame 20, the bottom surface 58 of the flange portion 52 resting on the top surface 72 of the base collar 71. The top surface 62 of the access cover 60 is now at substantially the height of the new base course to be laid. A replacement first extension collar 30 up to this height is now added to the main frame 20.

Once the new base course has been laid, the service frame 50 and access cover 60 are once more removed or raised from the main frame 20 and the height-adjustable spacer element 80 is relocated on the top surface 72 of the base collar 71. The service frame 50 and access cover 60 are then placed back into the main frame 20, the bottom surface 58 of the flange portion 52 resting on the top surface 82 of collar 81 or on the top surface 87 of wedge 86 (and the top surfaces of the other wedges not shown) depending upon whether or not the wedges have been inserted in the recesses. A second extension collar 40 is added to the first extension collar 30 to bring the main frame 20 to substantially the new level of the wear course to be laid. The wear course is then laid and the height of the service frame 50 can be adjusted if necessary via the wedges, such as that shown at 86, so that the top surface 62 of the access cover 60 lies substantially flush with the newly laid wear surface.

It will be appreciated that tilt of the road can be catered for by adjusting the wedges by differing amounts.

When the level is correct, grout or cement or other packing material is inserted in the gap between the bottom surface 58 of the flange portion 52 of the service frame 50 and the upper surface 82 of the collar 81 of the height-adjustable spacer element 80.

When this material has set, the wedges are either removed or left in place.

When the time comes again for the road to be resurfaced, the wedges are reinserted into their former positions and the service frame 50 is raised.

By this process the grout or cement in the gap between the service frame 50 and collar 81 and also the base and wear course material in the space between the vertical wall 51 of the service frame 50 and the extension collars 30 and 40 are fractured. The use of the extension collars 30 and 40 obviates the need to fracture material not lying in this space, which would require significant additional force.

Alternatively, if the road is to simply have another wear layer laid over the existing wear course 7, all that is required is for the service frame 50 to be raise up to and set at the new level and this is achieved in the manner as detailed above.

With regard to the support means as shown in Figures 4 and 5, the wearing surface is resurfaced in a similar manner to that described above. The adjustment of the height of the service frame 50, however, is effected through the use of hydraulic jacks, rams, pulling or lifting apparatus as hereinbefore described and the height-adjustable spacer element 80 may accordingly be dispensed with.

The device and method of the present invention address many of the problems associated with the prior art, for example the hazard of parts of the supporting frame standing proud of the surface. The device of the present invention may be used in a variety of differently sized access holes. Inspection of the access hole is relatively simple and the device is easy to dismantle. Fine adjustment and tilt of the access cover is provided.

Claims

CLAIMS:

1. A device for mounting an access cover in a wearing surface, for example a road surface, having a wear course overlying a base course, the device comprising a service frame in which the cover is removably received and a main frame for mounting below the base course, wherein the service frame is movable to a plurality of positions relative to the main frame including a first position at which a top surface of the access cover is substantially flush with the top surface of the wearing course and a second position at which the top surface of the access cover is substantially flush with the bottom surface of the base course.

2. A device as claimed in claim 1, wherein the service frame is supported on the main frame by support means.

3. A device as claimed in claim 2, wherein the support means are adjustable and/or removable.

4. A device as claimed in claim 3, wherein adjustment and/or removal of the support means enables the service frame to be moved relative to the main frame to a plurality of positions including the first and second positions.

5. A device for mounting an access cover in a wearing surface, for example a road surface, having a wear course overlying a base course, the device comprising a service frame in which the cover is removably received, a main frame for mounting below the base course, and support means to support the service frame on the main frame at a first position at which a top surface of the access cover is substantially flush with the top surface of the wearing course, wherein removal and/or adjustment of the support means enables the service frame to be moved relative to the main frame to a second position at which the top surface of the access cover is substantially flush with the bottom surface of the base course.

6. A device as claimed in any one of the preceding claims, wherein the service frame is an open annular or rectangular frame having at a base thereof an outwardly extending flange.

7. A device as claimed in any one of the preceding claims, wherein the main frame is an open annular or rectangular frame having at a base thereof an inwardly extending flange.

8. A device as claimed in any one of the preceding claims, wherein the main frame surrounds the service frame at the second position.

9. A device as claimed in any one of claims 2 to 8, wherein the support means comprises one or more collars or one or more height-adjustable spacer elements or a combination thereof.

10. A device as claimed in any one of claims 6 to 8, wherein the support means comprises one or more collars disposed between an upper surface of the flange of the main frame and a lower surface of the flange of the service frame.

11. A device as claimed in claim 9 or claim 10, wherein the one or more collars comprise separable segments.

12. A device as claimed in claim 10 or claim 11, wherein the support means further comprises a heightadjustable spacer element.

13. A device as claimed in claim 9 or claim 12, wherein the height-adjustable spacer element comprises a collar and wedge arrangement.

14. A device as claimed in claim 9 or claim 12, wherein the height-adjustable spacer element comprises a collar having one or more adjustable screws running therethrough.

15. A device as claimed in claim 9 or claim 12, wherein the height-adjustable spacer element comprises one or more hydraulic jacks or rams or a combination thereof.

16. A device as claimed in any one of the preceding claims, further comprising one or more extension collars located on a top portion of the main frame.

17. A device as claimed in any one of the preceding claims, further comprising one or more spacer elements located on a top portion of the service frame.

18. A method of resurfacing a wearing surface having a wear course overlying a base course, wherein a device as claimed in any one of the preceding claims is sited in the wearing surface, the method comprising the steps of: (a) moving the service frame to the second position; (b) planing down the wear and base courses to the desired depth; (c) moving the service frame relative to the main frame to a position such that the top surface of the access cover will be substantially flush with the top surface of the base course to be laid; (d) laying the base course; (e) moving the service frame such that it will be at substantially the first position when the wear course is laid; and (f) laying the wear course.

19. A method of laying a new wear surface on a wearing surface having a wear course overlying a base course, wherein a device as claimed in any one of the preceding claims is sited in the wearing surface, the method comprising the steps of: (a) moving the service frame to a level at which the top surface of the access cover will be substantially flush with the top surface of the new wear course to be laid; and (b) laying the wear course.

20. A method of resurfacing a wearing surface having a wear course overlying a base course, wherein a device as claimed in any one of the claims 5 to 17 is sited in the wearing surface, the method comprising the steps of: (a) removing and/or adjusting the support means such that the service frame is in the second position; (b) planing down the wear and base courses to the desired depth; (c) reinserting and/or adjusting the support means such that the top surface of the access cover will be substantially flush with the top surface of the base course to be laid; (d) laying the base course; (e) adjusting the support means such that the service frame will be at substantially the first position when the wear course is laid; and (f) laying the wear course.

21. A method of laying a new wear surface on a wearing surface having a wear course overlying a base course, wherein a device as claimed in any one of claims 5 to 17 is sited in the wearing surface, the method comprising the steps of: (a) adjusting the support means to raise the service frame to a level at which the top surface of the access cover will be substantially flush with the top surface of the new wear course to be laid; and (b) laying the wear course.

22. A device substantially as hereinbefore described with reference to the drawings.