GB2265174A - Height adjuster for a boundary box or manhole cover in a paved location - Google Patents

Abstract

A cover height adjuster which can be used for a boundary box, a manhole cover etc. in a paved location, comprises two rings (10, 18) with interengaging sloping castellated end surfaces extending around the peripheries of at least three sectors of the rings such that the height of the upper ring (18) can vary upon its rotation over the lower ring (10). The upper surface (21) of the upper ring (18) may have a slope which engages a sloping surface (29) of a cover assembly, so that relative rotation can also vary the slope of the cover. <IMAGE>

Description

COVER HEIGHT ADJUSTER This invention relates to a cover height adjuster which can be used for example in conjunction with a meter box installation, a boundary box, a valve cover, a manhole cover, or a drainage grate.

In the above mentioned installation and many others, there is frequently a need for access to be provided for subterranean apparatus for example, a water meter or valve, or a manhole cover in a road surface. It is a relatively simple matter to install a cover for example to be in a roadway oriented to the same angle as the road surface in which it is located and further to be substantially coplanar with the surrounding road surface. However as the road wears and is resurfaced, either or both the surface level and camber can change and one of the objects of this invention is to provide means whereby at least the height can be varied so that a single cover assembly can be utilised for a range of situations which are encountered in practice.

Another problem sometimes encountered is variation of position, height or camber due to vibration and load imparted by traffic to a cover in a road surface, particularly if the cover is ill-fitting, a situation which frequently exists. Vibration can cause both settlement of the ground and rotation of a cover, both of which, if surmounting a tapered spacer ring, will increase error of location with respect to the surrounding road surface. Another object of this invention is to provide means which will both provide not only ready height adjustment means but will also inhibit rotation.

According to the invention there is provided a cover height adjuster assembly comprising two rings having end surfaces spaced axially from one another and extending around the peripheries of sectors of each of the rings, some at least of said end surfaces of each ring being contiguous when the rings are co-axial, and sloping so that, upon relative rotation of the rings, the distance between the other end surfaces varies.

Preferably, the cover height adjuster assembly comprises two rings (or sleeves) having interengaging end surfaces which are spaced axially from one another (for example, castellated surfaces) and extend around the peripheries of sectors of each of the rings, and being engageable in such a way that one ring can be positioned on another in any one of a plurality of rotational positions, and by rotation can raise or lower its upper surface with respect to the height of the lower ring. The upper surface of the upper ring can slope, and engage a sloping surface on the cover, so that the slope of the cover can be varied by rotation with respect to the other ring.

More specifically, a cover height adjuster assembly of this invention consists of two rings having end surfaces spaced axially from one another and extending around the peripheries of sectors of each of the rings, some at least of said end surfaces of each ring abutting complementary said end surfaces of the other ring when the rings are co-axial and, upon relative rotation of the rings, varying the distance between them.

An embodiment of the invention is described hereunder, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a lower ring having four sectors each with a castellated periphery; Figure 2 is a central section taken on line 2-2 of Figure 1; Figure 3 is an underside view, but otherwise similar to that of Figure 1, and showing the configuration of an upper ring, which is complementary to the lower ring; Figure 4 is a central section taken on line 4-4 of Figure 1; Figure 5 is a plan view of a tapered cover support ring which is useful for varying the camber of a lid; Figure 6 is a central section through Figure 5; and Figure 7 shows an assembly with a cover in place.

Figures 1 and 2 show a lower ring 10 which has an outer cylindrical portion 11, the cylindrical portion 11 terminating at its lower end in a register recess 12 by which the ring can be supported from the open mouth of an upstanding tube in the ground (as shown in Figure 7).

The upper edge of the ring 10 comprises four sectors 13 each of which occupies 900, and the periphery of each sector 13 is divided into a plurality of steps 14 separated by notches 15, and each step is either higher or lower than its next adjacent step thus forming a castellated configuration. For stability there must be at least three sectors 13.

Figures 3 and 4 correspond to Figures 1 and 2, and illustrate a complementary upper ring 18. When co-operating with a complementary shaped ring, the complementary shaped ring can be elevated by simply lifting it, rotating it, and lowering it to engage another set of steps and notches (also numbered 14 and 15), the surfaces of which inhibit further relative rotation and effect a height change. Rotation could otherwise occur due to the steep helix angle of the castellated sections 13. The height adjustment method made available by this invention eliminates the need to dig out a meter box, for example, and reposition it, as frequently occurs in current practice upon soil settlement.

The complementary upper ring 18 is provided with female steps 14 which will engage the notches 15 of lower ring 10 and notches 15 of the ring 18 will be engaged by the steps 14 or lower ring 10, and quite clearly there is no need for a separate sleeve to surround the castellated sectors, although in most instances this is preferred. However as shown in Figures 2 and 4, the dimension D can be the same so that the skirt 19 of ring 18 can surround lower ring 10 as in Figure 7, and ensure that concentricity is maintained even under adverse conditions.

The upper ring 18 terminates at its upper end in a spigot 20 the side walls of which are co-operable with the side walls of a register recess 12 of the lower ring (Figure 2), as illustrated the configuration of Figure 4 being complementary to that of Figure 2. The upper surface 21 of the spigot 20 is not parallel to the lower surface 22 of the ring 18, but as shown in Figure 4, slopes by an amount sufficient to enable a cover lid to approximately match road camber, when 18 overlies complementary ring 10, itself on an upstanding pipe 24 (Figure 7), the rings and pipe all being subterranean.

However, usually there is need for both packing and camber adjustment beyond the limits of the castellated and sloping steps, and Figures 6 and 7 show a plain cover support ring 28 having a lower edge 29 which defines the bottom extremity of a register recess 30 to receive spigot 20 of upper ring 18. The lower edge 31 of cover support ring 28 slopes in a manner similar to the upper edge 21 of the upper ring 18. The upper end of ring 18 terminates in a spigot 33 identical to the spigot 20, and therefore functions in an identical manner. As shown in the Figure 7 configuration, spigot 33 engages in a register recess 34 in the lower end of a square manhole cover surround 35 which carries a cover 36 screwed at 37. Seals 38 and 39 inhibit moisture ingress. Cover surround 34, in being square, does not tend to rotate, but if the cover surround is circular, rotation may be limited by use of projections and matching recesses between the engaging surfaces of upper ring 18, cover support ring 28 will vary the slope of the cover surround 35 and cover 36.

The dotted lines on Figure 7 illustrate the manner in which the distance between rings 10 and 18 may be increased upon relative rotation.

Although the invention will be seen to be one of considerable simplicity it nevertheless fulfils a long felt need in the art of manhole covers, water meter covers, grates, or valve covers and other areas where there is a need for human interference with the subterranean equipment buried beneath a road or path surface. The invention achieves control of both height and slope of a manhole cover and cover surround.

Claims (7)

1. A cover height adjuster assembly comprising two rings having end surfaces spaced axially from one another and extending around the peripheries of sectors of each of the rings, some at least of said end surfaces of each ring being contiguous when the rings are co-axial, and sloping so that, upon relative rotation of the rings, the distance between the other end surfaces varies.

2. A cover height adjuster assembly according to claim 1 wherein said axially spaced end surfaces are castellated surfaces.

3. A cover height adjuster assembly according to claim 2 wherein said castellated surfaces comprise steps separated by notches.

4. A cover height adjuster assembly according to any preceding claim wherein there are at least three said sectors.

5. A cover height adjuster assembly according to any preceding claim wherein (in use) one of said rings is vertically above the other, and the upper of said rings comprises a skirt which surrounds the lower of said rings.

6. A cover height adjuster assembly according to claim 5 further comprising a cover support ring having a depending skirt with a sloping lower surface, said upper ring also having a sloping upper surface which abuts said sloping lower surface such that upon rotation of the cover support ring, with respect to the upper ring, slope of an upper face of said cover is adjustable.

7. A cover height adjuster assembly substantially as herein defined with reference to the accompanying drawings.