EP0991822A1

EP0991822A1 - A well cover lifting tool

Info

Publication number: EP0991822A1
Application number: EP98929238A
Authority: EP
Inventors: Jakob Munch-Fals
Original assignee: MUNCH FALS JAKOB
Current assignee: MUNCH FALS JAKOB
Priority date: 1997-06-27
Filing date: 1998-06-25
Publication date: 2000-04-12
Also published as: WO1999000553A1; AU7907798A

Abstract

A tool (1) serving for manually handling a well cover (22). The tool is constructed around a trilateral grating with a first, second, and third bar (3, 4, 5). At the top, the first bar (3) is provided with a handle (9), and at the bottom, a cross axle (10) with a wheel (11) at each end is fitted at the joint between the first and third bar (3, 5). The tool furthermore comprises a rocker arm (13) tiltable around a bearing (12) extending mainly parallel to the axle. Two lifting keys (28) for detachably engaging with corresponding keyholes (35) in the cover are placed on the outer part of the rocker arm with mutual spacing in the longitudinal direction. The tool furthermore has a stop (19) for limiting the turning of the rocker arm. In use, the tool is used firstly as a long crowbar, for breaking the cover free of the curb using little strength, secondly as a lifting tool for lifting the cover, and finally as a trolley for transporting the cover away from the curb. The tool has a simple construction, it is easy to use and affects the operator with less physical load than known so far.

Description

A well cover lifting tool

The invention relates to a tool for manually lifting a well cover comprising a frame with an upper handle and two coaxially placed wheels for bearing on a foundation next to the cover in use.

Normally, a well cover is in itself heavy and to this must be added that it, in the course of time, can often get firmly stuck in its well curb due to compressed material, rust, and damp. It therefore takes great strength to handle a well cover and especially to loosen and lift it clear of the curb.

For this purpose, a crowbar is typically used for initially loosening the cover from the curb, after which it is lifted by means of lifting keys engaging with corresponding keyholes or the like in the cover.

In default of aids on site, the operation is often carried out manually. However, the hard work is destructive to the operator's back and health.

In order to avoid injuries of this kind, the cover is sometimes instead lifted by means of e.g. a crane which is often complicated to use and rarely available when it is to be used. Thereby, the operator is forced to either wait for the right lifting tools to arrive or lift the cover manually.

Special tools for handling well covers have also been developed. In its simple form, these tools are comprised of an L-shaped lever which in use bears on the foundation at the curb and with a lifting key engages with a lifting opening or the like in the cover. When the operator pulls at the lever, the cover is lifted clear at one side whereupon the operator can drag it out of the curb by turning the lever round the fulcrum on the foundation. In an improved embodiment, the -shaped lever is provided^" with wheels so that the operator is able to drag the cover out of the curb by pulling the lever across the foundation, but in both cases, the work to remove the cover from the curb is time- consuming, laborious, and hard on back and limbs, and furthermore it often involves risk of the operator being injured.

The object of the invention is to provide a tool of the kind mentioned in the opening paragraph that is of simple construction, quickly to use, and when in use affecting the operator with less physical load than known so far.

The novel and unique features according to the invention, whereby this is achieved, is the fact that the tool comprises a rocker arm fitted on the frame tiltably around a tilt bearing extending mainly parallel to the wheel axis, that one part of the rocker arm is extending inwards and the other part outwards in relation to the frame, that at least two lifting keys for detachably engaging with corresponding keyholes or similar engageable parts in the cover are placed on the second part with mutual spacing in the longitudinal direction, and that a stop is provided for limiting the turning of the first and second part of the rocker arm upwards from and down towards the foundation respectively.

In this way, the tool can be used for as many as three successive working operations that altogether enables the operator to remove the cover from the curb easily and quickly. Firstly, the tool is used as a long crowbar for breaking the cover free of the curb using little strength, secondly as a lifting tool for lifting the cover, and finally as a trolley for transporting the cover away from the curb.

In an expedient embodiment, the frame can be constructed as a trilateral grating, the tilt bearing, wheel axle, and handle then being placed on each their end of the triangle. The- sides of the triangle can be single or double bars in the shape of e.g. braces whereby an especially rigid and user friendly construction is obtained. In both cases, the bars can be pivotally connected to each other at the ends of the triangle so that the frame advantageously can be folded. In folded condition, the tool takes up very little room, and can therefore easily be brought along to a workplace where a well cover has to be removed in order to obtain access to a well.

In some cases, the rocker arm can be comprised merely of a single, continuous bar in the form of e.g. a square bar. However, it is an advantage if the projecting part of the rocker arm has a detachable extreme section with keys for engaging with the cover. The tool can thereby namely be adapted quickly and easily to remove covers with different arranged grip parts.

The invention will be explained in greater detail below, describing only exemplary embodiments and disclosing additional advantageous characteristics and effects of operation with reference to the drawing, in which

Fig. 1 is a perspective view of a first embodiment of a tool according to the invention,

Fig. 2 is a side view of the tool shown in fig. 1 at a first stage of an operation for removing a well cover from a well,

Fig. 3 is the same but at a second stage,

Fig. 4 is the same but at a third stage,

Fig. 5 is a perspective view of a second embodiment of a tool according to the invention,

Fig. 6 is the same but in folded condition,

Fig. 7 is a perspective view of a third embodiment of a tool according to the invention, Fig. 8 is the same but in folded condition,

Fig. 9 shows a longitudinal cross-section of a tool with keys for lifting a well cover, and

Fig. 10 is a perspective view of the tool in fig. 9.

Fig. 1 shows a first embodiment of a tool 1 according to the invention. The tool is constructed around a trilateral grating 2 comprised of a first, second, and third bar 3,4,5. The bars, which e.g. can be pipes, are welded together at the ends of the triangle 6,7,8.

The first bar 3 is elongated into a handle 9, and a cross axle 10 is welded to the grating 2 at the end 7 between the first and the second bar 3,5. A wheel 11 is revolvably fitted on each end part of the axle 10.

A transverse bearing 12 for a rocker arm 13 with an inner part

14 and an outer part 15 is placed at the end 8 between the second and the third bar 4,5. In this case, the rocker arm is comprised of two roker arms 16,17 interconnected by a cross-arm 18.

A stop 19 is fitted on the first bar 3, and as it appears, the rocker arm can tilt around the bearing 12 from a first position where the inner part 14 of the rocker arm abuts on the axle 10, and to the second position shown in fig. 1 where the inner part abuts on the stop 19. On the under-surface of each bar 16,17, a notch 20 is furthermore made which fits the axle 10. On at least one side of the rocker arm, an extension spring 21 is fitted extending between the rocker arm 13 and the axle 10 and serving for forcing the rocker arm into its first position when the tool is not loaded.

In fig. 2, 3, 4 is seen how the tool shown in fig. 1 is used for handling a well cover 22 on a shaft 23 which at the top is ended by a curb 24 on level with the foundation 25 which e.g. can^" be a pavement or a road.

For this purpose, the lifting tool 26 shown in fig. 9 and 10 is detachably fitted on the outer part 15 of the rocker arm 13. The lifting tool 26 is comprised of a square pipe 27 with two lifting keys 28 extending through bushes 29,30 in the pipe 27 with mutual spacing.

Each key 28 is comprised of an upper part 31 turnable by means of a toggle 32, and a lower part 33 with a T-piece 34 at the bottom, the T-piece can be pushed through an oblong keyhole 35 in the cover 22 (fig. 2,3,4) . The distance between the keys 28 can be adapted to the distance between the keyholes 35 in a given cover by displacing one of the bushes 30 in longitudinal mortises 36 in the pipe 27.

A pin 37 which can be pushed into a corresponding hole (not shown) in the rocker arm serves for fixing the lifting tool in relation to the rocker arm.

When the tool is not loaded, extension springs 21 keep the rocker arm 13 in its first position in which the inner part 14 of the rocker arm abuts on the axle 10, and the rocker arm is therefore extending in almost the same direction as the third bar 5. This ensures that the frame does not overturns during mounting of the lifting tool 26 on the well cover 22.

As shown in fig. 2, the unloaded tool is, in this first tilt position, at first wheeled over a well cover 22 with the rocker arm 13 and thereby the fitted lifting tool 26 placed in a mainly horizontal position, and the lifting keys in position over the oblong keyholes 35 in the cover 2. The T-piece 34 of each key 28 is then pushed down through the opposite keyhole 35 and turned 90° by the toggle 32 which therefore conveniently is oriented in the same direction as the T-piece 34. The well cover is now fastened to the lifting tool 26 and thereby the tool 1. In fig. 3, the operator (not shown) is pulling on the handle 9 of the tool 1 in the direction indicated by the arrow, whereby the tool is turned round the support of the wheels 11 against the foundation 25, and at the same time, the rocker arm 13 starts turning to its second position under the influence of the weight of the well cover 22.

When the operator then continues to turn the tool and pressing the handle diagonally downwards, the well cover is, as shown, lifted diagonally upwards, successively being loosened from the curb from the side closest to the wheels 11, and this movement stops when the relative turning movement of the rocker arm 13 is stopped by the stop 19. At the stage shown in fig. 3, the tool is then functioning as a long crowbar for loosening the cover from the curb, and the operator can therefore easily and effortlessly disengage the cover even if it is firmly stuck by compressed material, rust, and damp

If the operator now turns the tool even further, it will function as a lifting tool that lifts, as shown in fig. 4, the entire cover above the foundation level so that the operator can use the tool as a trolley for transporting the cover away from the shaft 23 in the direction indicated by the arrow.

As shown, the same tool advantageously fills/performs as many as three functions by means of the invention, namely that of a crow-bar, of a lifting tool, and of a trolley. When the cover is to be replaced on the well, all three functions are then put into service again but in reverse order.

Fig. 5 and 6 show a second embodiment of a tool according to the invention. This structure corresponds essentially to the one shown in fig. 1 - 4, and corresponding components are therefore similarly referenced.

The difference is that the bars 3,4,5 are pivotally interconnected instead of being welded together, and a swing joint 38 is fitted between the first and the second bar 3,4. By way of this construction, the significant advantage is obtained^" in that the tool, as shown in fig. 6, can be folded so that it takes up less space during storage and transport.

The tool will take up minimum space if the swing joint 38 has a length that essentially corresponds to the sum of the length of the second and the third side 4,5 minus the length of the first side 3, as the two sides 4,5 then will be lying very close to the first side 3, when the tool is folded, as shown in fig. 6.

Fig. 7 and 8 show a third embodiment of a tool according to the invention. This structure corresponds essentially to the one shown in fig. 5 - 6, and corresponding components are therefore similarly referenced.

In this case however, the first and the second bar 39,40 are comprised of U-shaped braces while the third bar is comprised of two separate bars 41 placed on each side of the rocker arm 42.

As the structure shown in fig. 5 and 6, the bars 39, 40, 41 are pivotally interconnected, and the tool can therefore be folded completely, as shown in fig. 8.

In this case, the rocker arm 42 is comprised of an inner and an outer square pipe 43,44 that can be telescopically pushed into each other if necessary so that the projection of the rocker arm can be adapted to different working situations, cover structures, and lifting tools. The outer square pipe 44 can be put inside the pipe 27 on the lifting tool 26 and thereby create a rigid connection between the rocker arm 42 and the lifting tool 26. Other lifting tools can also be attached on the pipe 44, and analogously with the lifting tool 26, these are provided with a cotter 37 that can fit a hole 49 and thereby lock the lifting tool onto the pipe 44.

The stop for limiting the movement of the rocker arm is not placed on the first bar as in the first and second embodiment of the tool, but is instead comprised of a U-shaped stop-brace 45 with legs 46 extending on each side of the square pipe 43 of the^" rocker arm and pivotally connected to the axle 10.

A guide in the shape of two projections 47,48 placed on each their side of the respective brace legs are provided on each side of the square pipe 43 of the rocker arm. In the case shown, the projection 47 is a guide pin and the projection 48 is a rotatable roller.

As shown in fig. 8, the guides ensure that the stop-brace 45 are folded with the rocker arm 13 when the tool is folded, and that the engagement with the rocker arm maintained, as shown in fig. 7, so that the stop-brace can prevent the rocker arm from being swung to the second position where the tool functions as a lifting tool and a trolley. The spring 21 on the stop-brace 45 holds on the rocker arm when the tool is folded.

It is to be noted that the tool can be used for handling all types of covers with widely different grip configurations. The lifting tool shown in fig. 9 and 10 is only an example of how a lifting tool can be arranged.

Some covers do not have oblong keyholes but instead lifting rings. In this case, the keys will be in the nature of hooks for hooking into the rings.

In other cases, the cover has to be gripped at its periphery or in notches in the periphery. This demands a tool construction with downwards facing fingers that can be clamped along the periphery of the cover or peripheral notches.

Claims

C 1 -a i m s

1. A tool (1) for manual handling of a well cover (22) comprising a frame with an upper handle and two coaxially placed wheels for bearing on a foundation next to the cover in use, characterized in that the tool furthermore comprises a rocker arm (13) fitted on the frame tiltably around a tilt bearing extending mainly parallel to the wheel axis, that one part of the rocker arm (13) is extending inwards and the other part outwards in relation to the frame, that at least two lifting keys (28) for detachably engaging with corresponding keyholes (35) or similar engageable parts in the cover (22) are placed on the second part with mutual spacing in the longitudinal direction, and that a stop (19) is provided for limiting the turning of the first and second part of the rocker arm (13) upwards from and down towards the foundation respectively.

2. A tool (1) according to claim 1, characterized in that the frame is mainly shaped as a triangle with a first, second, and third side, and that the tilt bearing is placed at the end of the second and third side, the axle at the end of the third and first side, and the handle at the end of the first and second side.

3. A tool (1) according to claim 1 or 2 , characterized in that the frame is constructed as a trilateral grating with a first, second, and third side part.

4. A tool (1) according to claim 3, characterized in that the first, second, and third side parts of the grating are comprised of a first, second, and third bar.

5. A tool (1) according to claim 3, characterized in that the first and second side part of the grating each are comprised of a U-shaped brace, that the rocker arm (42) is placed between the legs of these braces, and that the third ^ΓÇó side part of the grating is comprised of two bars ^""(41) placed on each side of the rocker arm (42) .

6. A tool (1) according to claim 3, 4, or 5 , characterized in that the side parts of the grating are pivotally interconnected, as a swing joint (38) is being fitted between the first and second side part and having a length which essentially corresponds to the sum of the length of the second and the third side (4,5) minus the length of the first side (3) .

7. A tool (1) according to each of the claims 1 - 6, characterized in that a spring (21) is fitted between the rocker arm (13) and the frame, the spring is made to hold the rocker arm in a position approximately in alignment with the third side of the grating in the position of rest of the tool .

8. A tool (1) according to each of the claims 1 - 7, characterized in that the stop (19) for limiting the turning of the first and second part of the rocker arm (13) upwards from and down towards the foundation respectively is fitted on the first side part.

9. A tool (1) according to claim 5, 6, or 7 , characterized in that the rocker arm (13) is comprised of a bar in the form of e.g. a square bar, and that the stop for limiting the turning of the first and second part of the rocker arm (13) upwards from and down towards the foundation respectively is comprised of a U-shaped brace with legs extending on each side of the bar, is guided by projections and/or wheels on the bar sides and revolvably connected to the axle .

10. A tool (1) according to each of the claims 1 - 9, characterized in that the second part of the rocker arm (13) has a detachable external section with keys for ^ΓÇó engaging with corresponding keyholes or similar engageable parts in the cover.