GB2272396A

GB2272396A - Access cover lifter

Info

Publication number: GB2272396A
Application number: GB9322997A
Authority: GB
Inventors: Reginald William Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-11-13
Filing date: 1993-11-08
Publication date: 1994-05-18
Anticipated expiration: 2013-11-08
Also published as: GB2272396B; GB9322997D0; GB9223777D0

Abstract

An access cover lifter 11 comprises a lever bar 19 pivotal about a ground-engaging fulcrum 16 and having an access cover-engaging key 18 positioned at one end of the bar. When the key is in engagement with an access cover 12, effort applied to the opposite end of the bar, at handles 21, enables the cover to be lifted. The lever bar is constructed from two side members with connectors between them (31, 32, 33 fig 2). Extra leverage may be provided by an extension bar (35, fig 2) which fits into the handle end of bar 19. A set of lifter keys may be provided to enable engagement with different access covers. <IMAGE>

Description

ACCESS COVER LIFTER This invention relates to access cover lifters such as are used to lift access covers in roads and pavements to gain access to subterranean workings.

Manhole covers come in a range of shapes, though all much of a size, but with keyholes which are individual, perhaps, to the manufacturer of the cover or to the utility, e.g. telephone company, gas company or the like for which the cover is provided. The keys supplied with the cover are usually part of a lifting handle.

Covers are usually made of iron, sometimes with a concrete filling, and are in any event heavy.

Moreover, the cover not infrequently becomes more or less stuck whether from rust or from ingress of road dirt and stones into the space between the cover edge and the shelf on which it rests, so that considerable effort is often required to first dislodge and then lift it, for which the usual lifting tool is often quite inadequate and unsuitable from an ergonomic viewpoint.

One improved lifting arrangement comprises a framework that straddles the cover standing on castors with a central screw jack. This is expensive and does not work when the cover stands surrounded by soft ground into which the castors sink once lifting effort is applied.

The present invention provides a relatively inexpensive access cover lifter which does not suffer from the disadvantages of prior art lifters.

The invention comprises an access cover lifter comprising a cover-fitting lifter key attachment position and spaced therefrom a ground-engaging fulcrum which can engage the ground beside the cover when the key engages the cover and about which the lifter can be pivoted with mechanical advantage.

The key attachment position may be at one end and the fulcrum intermediate the ends of a lever bar, closer to the key attachment position. The fulcrum may be displaced from a straight line joining the two ends of the bar whereby when the fulcrum engages the ground one or the other but not both of the ends of the bar can also engage the ground.

The lifter may have an effort-applying end provided with a handle.

The lifter key attachment end may comprise a clevis. The lifter may be provided with a set of keys adapted to fit different covers, and may also comprise stowage arrangements for such a set of keys.

The lifter may be provided with a lever extension bar for added leverage where necessary.

One embodiment of access cover lifter according to the invention will now be described with reference to the accompanying drawings, in which Figure 1 is a side elevation of the lifter showing the same in ready-for-lifting position at an access cover; and Figure 2 is a plan view of the lifter of Figure 1.

The drawings illustrate an access cover lifter 11 for an access cover 12 which sits on a ledge 13 of a manhole 14.

The lifter 11 comprises a cover-fitting lifter key attachment position 15 and spaced therefrom a groundengaging fulcrum 16 which can engage the ground 17 beside the cover 12 when the key 18 engages the cover 12 and about which the lifter 11 can be pivoted with mechanical advantage. The key attachment position 15 is at one end and the fulcrum 16 is intermediate the ends of the lever bar 19, closer to the key attachment position 15.

The fulcrum 16 is displaced from a straight line joining the two ends of the bar 19 whereby when the fulcrum 16 engages the ground 17 one or the other of the ends of the bar 19 but not both can also engage the ground.

The end of the bar 19 which is further from the fulcrum 16 - the effort-applying end - is provided with a handle 21 - in fact two handles 21 are provided, one projecting laterally from the bar.

The lifter key attachment position 15 comprises a clevis. A set of lifter keys, one such, 18, being illustrated, can be provided, each with a throughway for the clevis pin 23. The axis of the clevis pin 23 is parallel to the axis of the fulcrum 16 so that the change in the angle between the bar 19 and the ground can be accommodated as the lifter is pivoted by effort at the handle end to dislodge and lift the cover 12.

The lifter is fabricated from steel bar stock and has two side members 31,32 with connectors 33, the fulcrum 16 comprising a V-shaped plate on a framework 34. The clevis pin 23 fits into bearing eyes in the end of each side member.

In use the appropriate key 18 is fitted to the lifter 11 which is positioned as illustrated with the key 18 over the keyhole in the cover 12 and the fulcrum 16 on the ground by the cover 12. The key 18 is lowered to engage the keyhole - the lifter may require, to engage the key 18, to be revolved by 900 about the vertical axis constituted by the keyhole - and the handle end of the bar is urged downwardly to free and lift the cover 11. The handles 21 are appropriately situated to be kicked or urged downwardly by foot, whereby greater impact and lifting movement can be applied, backed by the full weight of the user if necessary, than if manual action were to be used.

Once the cover 12 is raised, the lifter 11 can be swung around on the fulcrum 16 and/or dragged away from the manhole supported on the fulcrum 16 using, if necessary, a rocking action to assist movement.

A lever extension bar 35 is provided which can be inserted between the side members 31,32 as seen in Figure 1 to give greater leverage when such may be required.

The spaces in the lever bar 19 between the side members 31,32 and the connectors 33 can be used for the storage of different cover keys.

Claims

1. An access cover lifter comprising a cover-fitting lifter key attachment position and spaced therefrom a ground-engaging fulcrum which can engage the ground beside the cover when the key engages the cover and about which the lifter can be pivoted with mechanical advantage.

2. A lifter according to claim 1, in which the key attachment position is at one end and the fulcrum is intermediate the ends of a lever bar, closer to the key attachment position.

3. A lifter according to claim 2, in which the fulcrum is displaced from a straight line joining the two ends of the bar whereby when the fulcrum engages the ground one or the other of the ends of the bar but not both can also engage the ground.

4. A lifter according to any one of claims 1 to 3, having an effort-applying end provided with a handle.

5. A lifter according to any one of claims 1 to 4, of which the lifter key attachment position comprises a clevis.

6. A lifter according to any one of claims 1 to 5, provided with a set of keys adapted to fit different covers.

7. A lifter according to claim 6, comprising storage arrangements for said set of keys.

8. A lifter according to any one of claims 1 to 7, provided with a lever extension bar for added leverage where necessary.