GB2027472A

GB2027472A - Road surface boxes

Info

Publication number: GB2027472A
Application number: GB7926189A
Authority: GB
Original assignee: BRICKHOUSE DUDLEY Ltd
Current assignee: BRICKHOUSE DUDLEY Ltd
Priority date: 1978-07-28
Filing date: 1979-07-27
Publication date: 1980-02-20
Also published as: GB2027472B

Abstract

A road surface box comprises a frame 11 and a grating or lid 17 carrying captive locking bolts 24 each of which (a) can engage a screw thread 29 in the frame to lock the lid and (b) can be engaged, after unlocking, by a tool 31 to lift the lid. As shown the bolt 24 is held captive by a nut 28. The locking/ lifting bolts may be replaced by turnbuckles. <IMAGE>

Description

SPECIFICATION Road or like surface boxes and gratings This invention relates to road or like surface boxes and gratings comprising a frame defining an aperture of rectanguiar or circular or other shape and a lid seated on the frame to close the aperture. Examples include an unventilated manhole cover, in which case the lid is unapertured, and a drain cover, in which case the lid is apertured, and in both of which cases the frame and lid cover an opening in the road or other surface. Another example is a gulley grating in which the lid is apertured and the frame and lid cover an elongated channel or gulley part in the road or other surface.

Such road or like surface boxes and gratings will be referred to hereinafter as "road surface covers of the type specified." An object of the invention is to provide a new and improved road surface cover of the type specified in which means are provided to lock the lid to the frame and to facilitate lifting of the lid from the frame.

According to one aspect of the invention we provide a road surface cover of the type specified wherein the frame has a seat on which the lid is supported, in or adjacent the seat a locking means with which a part of a locking member is engaged, the locking member having a first engagement part adapted to engage a first abutment surface of the lid to prevent movement of the lid away from the seat and the locking member having a second engagement part adapted to engage a second abutment surface of the lid to permit the lid to be lifted by the locking member.

The locking means may comprise a threaded bore and the locking member a threaded bolt one end of which is threadedly received in the threaded bore and the head of the bolt providing said first engagement part.

The shank of the bolt may be threaded only over a part of its length extending towards the head from the opposite end of the shank and the second engagement part being in the form of a nut tightened against the unthreaded portion of the shank.

A road surface cover according to the invention may be provided in combination with a lifting tool comprising a generally L-shaped member the shorter limb of the L being bifurcated and adapted to receive the shank of the bolt in the fork and to engage beneath the head thereof whereby when the bolt is disengaged from the frame and the bolt abutment engaged with the second abutment surface of the lid, the lid may be raised by means of the bolt.

The lifting tool may be provided with a spanner formation.

The spanner formation may be at or adjacent the free end of the longer limb and extend parallel to the shorter limb of the tool.

The shorter limb of the tool may be pro vided with upstanding lips at the free end of the bifurcated part.

The invention will now be described in more detail by way of example with reference to the accompanying drawings wherein: Figure 1 is a plan view of a manhole cover embodying the invention, Figure 2 is a section on the line A-A of Fig.

1, Figure 3 is a section on the line B-B of Fig.

1, and Figure 4 is a perspective view of a lifting tool used in combination with the manhole cover of Fig. 1.

Referring to the drawings a road surface cover embodying the invention is illustrated generally at 10 and comprises a manhole cover intended to cover a circular opening in a road surface.

The manhole cover 10 comprises a frame 11 having an upstanding flange 12, a base rim 1 3 and a seating part 1 4.

In order to provide a one way fit the flange 11 is provided with an outwardly extending pocket, indicated at 1.5 at one circumferential position and a projecting tongue on a man hole lid 1 7 is received therein.

The lid 1 7 comprises a generally circular disc shaped part 1 8 with a downwardly de pending peripheral flange 1 9 the lower sur face of which rests on the seating part 14.

At two diametrically opposite positions (and, in the example illustrated at 90 to the out wardly extending part 1 5 of the vertical flange 1 2) two further outwardly extending pockets 20 are formed in the vertical flange 1 2 and are adapted to receive lugs 21 projecting outwardly from the peripheral flange 1 9 of the cover 17. As shown in Fig. 3 each lug 21 has a cylindrical bore 22 formed therein through which the shank 23 of a bolt 24 extends. Each bolt 24 provides a locking member for the lid and has a head 25 adapted to engage the upper surface 26 of the lug 21. Thus the head 25 and upper surface 26 constitute a first abutment of the locking member and a first abutment surface of the lid respectively.The shank 24 is threaded from its free end for only a portion of the length of the shank as indicated at 27 and a nut 28 is engaged on the threaded part 27 and is tightened against the unthreaded part of the shank 24. The nut 28 provides a second abutment on the locking member.

In use, when it is desired to lock the lid 1 7 to the frame 11 the bolts 23 are manipulated to engage the threaded part 27 in a locking means comprising a threaded bore 29 formed in the base rim 1 3 so that the head 25 is engaged with the upper surface 26 of the lug 21 to thus lock the lid to the frame. Prefera bly each bolt 23 is provided with a locking means such as a nylon locking insert to pre vent inadvertant loosening of the bolt and displacement of the nut 28.

When it is desired to lift the lid from the frame the bolts are first rotated to disengage the threaded part 27 from the bore 29 and the bolts are then raised until the nut 28 engages the undersurface 30 of the lug 21, which thus constitutes a second abutment surface, so that the lid can be lifted by means of the bolts.

To facilitate this, two tools, one of which is shown in Fig. 4, are provided. The tool is indicated generally at 31 and is of L-shape having a shorter limb 32 and a longer limb 33. The shorter limb 32 is bifurcated to provide two spaced arms 34 with a slot 35 therebetween. Upturned lips 36 are formed at the free ends of the arms 34.

An hexagonal tube 37 is welded to the longer limb 33 adjacent the free end thereof to provide a box spanner formation.

The box spanner 37 is of such configuration as to engage with the head 25 of the bolt to permit of tightening and loosening of the bolt.

To lift the lid, each tool 31 is engaged underneath the heads 25 of the bolts as shown in chain dotted line in Fig. 3 and the box spanner formation 37 can then be grasped to facilitate lifting the lid. The lips 36 prevent inadvertent disengagement of the tools from the bolts 24.

It will be appreciated that the two pockets 20 and associated lugs 21 are of identical configuration and that a tool similar to the tool 31 described hereinbefore would be engaged with each bolt to permit of lifting of the lid. If desired the pockets and lugs may be of different configuration to each other and in this case a one-way fit would be provided without the need for the pocket 1 5 and tongue 16.

Although bolts 24 have been described in the above example as locking members in combination with threaded bores as a locking means, other forms of locking member and means may be provided such as a turnbuckle latch.

Although the example described hereinbefore has been a manhole cover of circular configuration the invention may be applied to other road surface covers including a manhole cover of a configuration other than circular, a drain cover of any desired configuration, or a kerb gulley cover or grating.

Claims

1. A road surface cover of the type specified wherein the frame has a seat on which the load is supported, in or adjacent the seat a locking means with which a part of a locking member is engaged, the locking member having a first engagement part adapted to engage a first abutment surface of the lid to prevent movement of the lid away from the seat and the locking member having a second engagement part adapted to engage a second abutment surface of the lid to permit the lid to be lifted by the locking member.

2. A cover as claimed in Claim 1 wherein the locking means comprises a threaded bore and the locking member a threaded bolt one end of which is threadedly received in a threaded bore and the head of the bolt providing said first engagement part.

3. A cover as claimed in Claim 2 wherein the shank of the bolt is threaded only over a part of its length extending towards the head from the opposite end of the shank and the second engagement part being in the form of a nut tightened against the unthreaded portion of the shank.

54. A cover according to any one of the preceding claims wherein the frame defines a generally circular opening and the lid is circular.

5. A cover according to Claim 4 wherein the locking means is provided in a pocket of the frame extending radially outwardly of the circular general periphery of the opening.

6. A cover according to Claim 5 wherein the locking member is received in a lug on the lid projecting outwardly of the general circular periphery thereof and received in a pocket of the frame.

7. A cover as claimed in any one of the preceding claims wherein a plurality of locking means and associated locking members are provided at positions spaced around the periphery of the lid and opening.

8. A cover as claimed in Claim 3 or any one of Claims 4 to 7 when dependant upon Claim 3 in combination with a lifting tool for the or each locking means and associated locking member, the or each lifting tool comprising a generally L-shaped member the shorter limb of the L being bifuracted and adapted to receive the shank of the bolt in the fork thereof and to engage beneath the head of the bolt whereby when the bolt is disengaged from the frame and the bolt abutment engaged with the second abutment surface of the lid, the lid may be raised by means of the bolt.

9. A cover and tool combination as claimed in Claim 8 wherein the lifting tool is provided with a spanner formation.

10. A cover and tool combination as claimed in Claim 9 wherein the spanner formation is at or adjacent the free end of the longer limb and extends parallel to the shorter limb of the tool.

11. A cover and tool combination as claimed in Claim 10 wherein the shorter limb of the tool is provided with upstanding lips at the free end of the bifurcated part.

1 2. A cover substantially as hereinbefore described with reference to and as shown in Figs. 1 to 3 of the accompanying drawings.

1 3. A cover and tool combination substantially as hereinbefore described with reference to Figs. 1 and 2 and with reference to and as shown in Figs. 3 and 4 of the accompanying drawings.