GB2308147A - Covering holes - Google Patents

Description

Coverings Holes The present invention relates to the covering of trenches or holes, for example in a road surface.

It is often necessary to dig holes or trenches in a road surface, for example to lay cable, or to access underground utility pipes. This usually causes a substantial disruption to traffic on the road, as the hole must be cordoned off, and traffic diverted around the hole until the work is complete, and the hole is filled.

As a temporary measure to reduce disruption to traffic, it is known to place substantial metal plates over the holes. However, the metal plates required must be thick and have an area much larger than that of the hole, and must be heavy to resist movement. The heavy plates required use of large amounts of material and are cumbersome to manoeuvre. In addition, it is usually necessary to secure the plates in place, for example by using cement on asphalt. The time required both to install the plate, and to remove it contributes to the amount of time for which the road is unusable.

The present invention provides a device for bridging a hole, for example a hole in a road or the like, the device comprising an expandable frame having a contracted condition in which it is insertable into a hole, and drive means for urging the frame into an expanded condition in which a plurality of engagement portions engage sides of the hole in which it is inserted, the frame having means for supporting a cover for the hole.

Thus, the bridging device according to the invention can simply be inserted into a hole, and the engagement portions urged outwards to engage the side of the hole, thereby locking the device in position. The cover can then be placed over the frame, and since the cover is supported by the frame, it can be much smaller than if the cover had to be self-supporting. The device can be removed simply by withdrawing the engagement member or contracting the engagement portions using the drive means. This can be much faster than removal of asphalt or cement used to secure a plate in position.

Advantageously, the drive means comprises a hydraulic ram. This may enable a large amount of force to be generated in a compact arrangement.

At least one engagement portion is preferably provided with outwardly projecting prongs. With this arrangement, when urged against the side of a hole, the prongs will become embedded in the side of the hole, and will resist lateral or vertical displacement of the device.

One or more engagement portions may have substantially planar outward faces. These may serve to distribute the force provided by the drive means over a relatively large surface area to stabilize the device. Optionally, packing pieces, for example lengths of wood, may be inserted between the engagement faces and the side of the hole.

This may be useful to distribute force more evenly, or if the sides of the holes are irregular or unstable, or if the hole is larger than the optimum for the support device.

In a development, the device is provided with a plurality of engagement members capable of extending from the frame in a plurality of directions. The drive means, which may comprise a plurality of drive members, for example one for each engagement member, may be arranged to urge all of the engagement members against a side of the hole, either sequentially or simultaneously. Provision of several engagement members may enable the device to be maintained more securely in position in the hole.

The frame may be shaped or otherwise adapted to engage a cover.

In a second aspect, the present invention provides a hole covering apparatus, comprising a bridging device according to the first aspect, and a cover adapted for use with said bridging device.

Preferably, the cover and the bridging device are arranged to co-operate to retain the cover on the bridging device. The cover may be lockably secured, which may help prevent tampering with the apparatus.

The bridging device and cover may be arranged so that, in use, the upper surface of the cover lies substantially flush with the periphery of a hole in which the device is installed. When the device is installed in a road, this may allow smoother traffic flow over the hole, and may also reduce the risk of the cover being dislodged.

Locating clips may be temporarily secured to a cover to support it over a hole, flush with the road. Movable engagement members provided on the cover can then be adjusted to secure the cover to the bridging device.

Thereafter, the locating clips may be removed. The use of locating clips may facilitate positioning of a cover over a hole before it is secured.

Alternatively, the cover may be provided with tapered or stepped edges, and the periphery of the cover may be arranged to rest on the periphrey of the hole. This may provide positive seating of the cover over a hole, and reduce the amount by which the cover projects above the periphery of the hole. The invention also provides a cover for use in such apparatus.

In a third aspect, the present invention provides a method of covering a hole, the method comprising inserting a bridging device into the hole in a contracted state; expanding at least a part of the bridging device so that engagement portions thereon engage the sides of the hole; and providing a cover over the bridging device. The method may also comprise a subsequent step of contracting the device and removing it from the hole. Thus, the invention may further provide a method of installing, removing or adjusting an article in a road comprising digging a hole in the road; installing, removing or adjusting said article; and covering the hole according to the third aspect when said article is not being worked upon.

In the above aspects, the cover may be provided preattached, or as an integral part of the bridging device.

This may enable installation and/or removal of the device as a single unit, which may be more convenient. Such a cover would usually be provided with apertures or removable portions to enable access to the drive means of the bridging device for expanding and contracting the device.

With presently available cutting apparatus, holes can be cut to a predetermined size with an acceptable degree of accuracy. Thus the hole can be cut to a size to suit a cover, which may be a standard size.

The cover may be interchangeable with a plurality of covers of varying shapes and/or sizes. This may enable a variety of holes to be covered.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying schematic drawings in which.

Fig.1 is a plan view of a support device according to the invention;and Fig.2 is a side view of the device installed in a hole, with a cover fitted.

Referring to Fig.1, a bridging device according to the invention comprises a frame comprised of tubular cross members 10 and side members 12, which in this embodiment are in the form of hydraulic cylinders in which pistons 14 are telescopically slidably mounted. Fluid supplied to the cylinders 12 from pump and reservoir 16 along pipes 18 causes the pistons 14 to be driven out of the cylinders 12, effectively expanding the support device.

Mounted on the ends of pistons 14 is an engagement plate 20, which in this embodiment is provided with spiked prongs 22. At the opposite end of the frame, a second plate 24 provided with further prongs 26 is mounted to the cylinders 12.

It will be appreciated that with the bridging device located in a hole in a contracted state, with the pistons 14 withdrawn within the cylinders 12, forcing fluid under pressure into the cylinders by means of actuator 16 will urge the engagement plates 20,24, in opposite directions, into opposed walls of the hole in which the support device is located, the prongs 22, 26 being driven into the material of the walls to lock the frame securely in position.

As can be seen in Fig 2, upright tubular posts 28 are provided at the four corners of the substantially rectangular frame comprised of members 10 and cylinders 12, and these are joined by upper side members cross 30 and upper cross members (not shown). The upper frame provided by these members 28 and 30 provides a load-bearing structure, having an upper support surface on which a cover 32 can be supported. In the embodiment shown in Fig.2, the cover is in position with its upper surface flush with the surface of the surround of the hole. Projections 34 on the lower surface of the cover engage sides of the load-bearing structure 28, 30 restraining movement of the cover 32.

The embodiment shown may be constructed from a variety of materials, particularly steel, which may be galvanised or otherwise treated to improve its corrosion resistance.

Other materials, including other metals or plastics may be used.

It will be appreciated that numerous other arrangements are possible, depending on the particular application for which the support device is intended. For example, the spikes 22, 26 may be omitted or lengthened, or replaced by other projections adapted to engage the material of the sides of the particular hole in which the support device is to be inserted. Packing pieces, for example of wood may be inserted between the engagement faces 20, 24 and the sides of the hole.

The hydraulic ram arrangement shown may be replaced by another drive mechanism for forcing the engagement plate 20 away from the remainder of the frame, or otherwise causing the device to expand. Examples of alternative mechanisms include rack and pinion, or screw threaded arrangements, in which relative rotation of counter threaded male and female members, eg a nut and bolt arrangement, may provide and maintain separation of two or more components. Numerous other arrangements for causing and maintaining relative movement between two members or otherwise expanding a portion of a frame will be apparent to those skilled in the art. The separation may be achieved by manual operation, or may be powered, eg. by an electric motor or by compressed air.

The support device may be provided with several relatively movable engagement portions; for example the embodiment shown in Figs 1 and 2 may be provided with a further set of pistons and cylinders substantially perpendicular to the pistons and cylinders 14, 12. These may be attached to, or may take the place of the cross members 10. The engagement plate 24 may be mounted on a further set of pistons mounted within cylinders 12, or in a further cylinder, so that both engagement plates 20 and 24 are urged outwardly with respect to the frame provided by the cross members 10 and cylinders 12.

The cover 32 may be provided with a locking mechanism, not shown to attach it securely to the load-bearing structure 28, 30, to prevent the cover being removed, and to inhibit access to the bridging device. This locking mechanism may be operable by means of a key. Locking mechanisms are well known, and any of a number of known mechanisms may be used. However, it is important that the locking mechanism does not significantly weaken the cover, and is not liable to be damaged by the ingress of dirt or grit, since the cover will be embedded in a road, and traffic may pass over it.

The support device may be secured in a hole simply by engagement the side walls of the hole. However, in some applications, particularly where the support device is required to cover a large hole, or to carry a heavy load, it may be desirable to provide one or more downwardly projecting legs or other base arranged to bear against the bottom of the hole. Such an arrangement may be adjustable to a plurality of different heights, or may be urgeable against the bottom of the hole by a drive mechanism similar to that used to urge the sideways-projecting engagement plates against the sides of the hole.

For covering larger holes or trenches, two or more support devices may be deployed in the same hole. These may each have individual covers, or two or more may be used to support a single cover. Where the hole is cut to defined standard dimensions, a specially pre-shaped and sized cover may be provided. A plurality of covers of standard sizes may be provided for use with a single frame.

Of course, a variety of frames of different sizes may be provided, according to the size of the hole to be filed.

The periphery of the cover may be provided with a step, lip, or taper to seat positively over the top of the hole or may be shaped to lie within the hole, the surface of the cover lying flush with the surface of the surrounding material.

The cover may be secured to the support device, as an integral part thereof, and an aperture provided in the cover to allow access and actuation of the drive member, for example rotation or reciprocal motion to actuate an hydraulic pump or rotary motion to turn a screw thread.

These and other modifications will become apparent to those skilled in the art.

Claims (17)

1. A device for bridging a hole in the ground, comprising an expandable structure having a contacted condition in which the structure is insertable into the hole, an actuator for expanding the structure to an expandable portion in which one or more parts of the structure are engagable with a wall or walls of the hole when the structure is inserted in the hole, and support means on the structure for supporting a cover for the hole.

2. A device according to claim 1, wherein the structure comprises a frame carrying the actuator and the support means, and an engagement portion movable relative to the frame, the engagement portion and edge of the frame engaging the hole when the structure is in the expanded position.

3. A device according to claim 1, wherein the structure comprises a frame carrying the actuator and the support means, and engagement portions movable in different directions relative to the frame, the engagement portions engaging the hole when the structure is in the expanded position.

4. A device according to claim 2 or claim 3, wherein the actuator comprises at least one hydraulic ram which sets on the engagement portion(s)

5. A device according to any one of claims 2 to 4, wherein the engagement portion(s)and/or solid edge of the frame has outwardly projecting prongs.

6. A device according to any one of claims 2 to 4, wherein the engagement portion(s) and/or the edge of the frame have substantially planar outward faces.

7. A device according to claim 3 having a plurality of actuators, and an actuator is associated with each engagement portions.

8. A hole covering apparatus comprising a bridging device according to any one of the preceding claims; and a cover adapted for use with said device.

9. A hole covering apparatus according to claim 8 wherein the cover has means for restricting natural movement of the cover relative to the bridging device.

10. A hole covering apparatus according to claim 8 or claim 9 wherein the cover has securing means for securing it to the bridging device.

11. A hole covering apparatus according to any one of claims 8 to 10 wherein the device and cover are arranged such that, in use, the upper surface of the cover lies substantially flush with the periphery of a hole in which the device is installed.

12. A hole covering apparatus according to any one of claims 8 to 11 wherein the cover has tapered or stepped edges.

13. A hole covering apparatus according to claim 8 wherein the cover is integral with the bridging device.

14. A method of covering a hole in the ground, the method comprising inserting a structure into the hole in a contracted condition; expanding the structure to an expanded position in which one or more parts of the structure engage a wall or walls of the hole; and providing a cover over the bridging device.

15. A device for bridging a hole substantially as herein described with reference to and as illustrated in the accompanying drawings.

16. A hole covering apparatus substantially as herein described with reference to and as illustrated in the accompanying drawings.

17. A method of covering a hole substantially as herein described with reference to the accompanying drawings.