WO1992010627A1

WO1992010627A1 - Levering tool

Info

Publication number: WO1992010627A1
Application number: PCT/GB1991/002141
Authority: WO
Inventors: Peter Gerald Watkin
Original assignee: Peter Gerald Watkin
Priority date: 1990-12-04
Filing date: 1991-12-03
Publication date: 1992-06-25
Also published as: AU9020791A; GB2265852A; GB9026344D0; GB2265852B; GB9311057D0

Abstract

A tool adapted for levering a member (9) from a beam (8) to which the member is secured comprises a tubular handle (1) secured to a tool head which defines two levers (4) interconnected by a cross member (3). The two levers (4) are laterally spaced apart and arranged such that they may be positioned beneath the member (9) on opposite sides of the beam (8) with the cross member (3) resting on the beam (8). The handle (1) extends substantially perpendicular to the beam (8) and the cross member (3) defines a fulcrum (5) about which the tool is rotated to bring the levers (4) into contact with the member (9) and prise it from the beam (8).

Description

LEVERING TOOL

The present invention relates to a tool for levering a member from a beam to which the member is secured and across a width of which the member extends.

A conventional sloping roof for a building comprises a regular array of spaced apart roof beams or trusses running up the slope of the roof and an array of horizontal battens running across the beams. Rows of tiles or slates are nailed to the battens. Generally a water-proof membrane of, for example, roofing felt is sandwiched between the beams and the battens. Typically the roof beams will be spaced apart with a centre to centre distance of approximately 40cm and the battens will be spaced apart with a centre to centre distance of 10 to 20cm. Each batten is secured by a nail or nails to each of the beams across which it extends.

When it is necessary to re-lay a roof, it is generally necessary to strip off all the slates or tiles and the underlying battens. This means that the battens must be levered off the beam and this is generally achieved using one or a pair of conventional claw-head hammers. If a single hammer is used, the claw end of the head is positioned beneath the batten to one side of the beam and the other end of the head is positioned above the beam adjacent the batten to be removed. The hammer must then be pulled in a direction which is diagonal to both the beam and the batten. There is a tendency for the hammer head to slip off the beam and either damage any underlying felt which might already be in position or drop into the void beneath the roof. Furthermore there is a tendency for the batten to splinter as a result of leverage being applied to the batten on only one side of the nail which secures it to the beam. Not only does this result in the batten being so severely damaged that it cannot be re-used but also it makes the job of clearing up debris after removing an old roof more time-consuming. Roofing contractors sometimes try to overcome this problem by using two hammers, one placed on each side of the beam from which a batten is to be levered but it is difficult for a worker to _> safely manipulate two hammers in this way and it is also inconvenient for a worker to have to carry two tools. This is particularly the case where a worker is already

SUB provided with a hammer carrying a spike for use in forming nail holes in slates.

Similar problems to those described above with regard to the removal of roofs arise in other circumstances. For example, the removal of floor boards using claw head hammers or crow bars generally results in splintering of the boards which greatly reduce their salvage value.

It is an object of the present invention to obviate or mitigate the problems outlined above.

According to the present invention there is provided a tool for levering a member from a beam to which the member is secured and across a width of which a member extends, comprising two levers, a cross member interconnecting the two levers, and a handle extending from the cross member, the levers being spaced apart and arranged such that they may be positioned beneath the member on opposite sides of the beam with the cross member resting on the beam to define a fulcrum about which the tool may be rotated to bring the" levers into contact with the member.

The levers may be defined by two arms extending from a sheet metal component secured to the handle, for example by welding. Alternatively the levers may be defined by elements of a cast head to which a tubular handle has been secured.

The tool may incorporate a hammer head arranged at one end of the cross member to enable its use as a simple hammer. The tool may further, or alternatively comprise, a spike secured to one end of the cross member to enable apertures to be formed in, for example, slates. Thus a single tool may be used for a variety of tasks.

In a preferred embodiment one or each of the levers defines a longitudinal slot opening to its end. This enables the tool to be used to withdraw nails from a member in which they are embedded, for instance to de-nail battens which can then be re-used.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Fig. 1 is a perspective view of a prototype embodiment of the present invention positioned on a roof structure indicated in broken lines; Fig. 2 is a view on lines 2-2 of Fig. 1; Fig. 3 is a view on lines 3-3 of Fig. 1; Fig. 4 is a plan view of an alternative embodiment of the present invention;

Fig. 5 is a view on the lines 5-5 of Fig. 4;

Figs. 6 to 9 show various elevations of a tool head according to a third embodiment of the present invention; and

Figs. 10 and 11 show a modification of the tool head of Figs. 6 to 9.

Referring to Figs. 1 to 3, the illustrated tool comprises a handle 1 on which a rubber grip 2 is mounted. The handle 1 is welded to a curved sheet steel cross member 3, the configuration of which is best appreciated from Fig. 3. Two levers 4 are defined by the cross member 3, the levers being located at opposite ends of an edge 5 defined by the cross member 3. Each of the levers defines a slot 6 suitable for use in removing nails in a conventional manner. End pieces 7 are welded to the cross member 3 to increase the strength and rigidity of the structure.

In use, the tool is initially positioned with the levers 4 arranged on opposite sides of a beam 8 from which a batten 9 is to be levered. The handle 1 is positioned so that it extends substantially perpendicular to the beam 8 with the edge 5 of the cross member resting on the upper surface of the beam. The tool is then advanced towards the batten 9 so that the levers 4 are located beneath the batten and the end members 7 rest on the top surface of the batten. This lifts the edge 5 a short distance above the upper edge of the beam 8. If the handle is then pulled in the direction of the arrow 10 the edge 5 swings down into contact with the beam 8 and thereafter forms a fulcrum about which the whole tool rotates, thereby lifting the levers 4 into contact with the underside of the batten 9 and lifting the batten clear of the beam 8, assuming that sufficient force is applied to pull out any nail or other fixing device (not shown) previously securing the batten to the beam.

It will be appreciated that as the tool is positively located by the engagement of the beam 8 between the levers 4 there is very little risk of the tool swinging sideways in an uncontrolled manner. Furthermore, a levering force is applied to the batten on both sides of the beam, thereby greatly reducing the risk of the batten being snapped or otherwise damaged during its removed. If used on a roof in which a membrane such as roofing felt is sandwiched between the batten and the beam, it is generally possible to insert the levers 4 beneath the batten 9 without tearing the membrane. Once the levers are in position, substantial force can be applied to the handle 1 without risk of tearing

SUBSTITUTE SHEET the membrane.

In the arrangement of Figs. 1 to 3, the tool is fabricated from welded components and it may be preferable to use as an alternative the combination of a tubular handle and a cast head defining the cross member and levers. Furthermore in the arrangement of Figs. 1 to 3 the edge 5 which defines the fulcrum about which the tool rotates is relatively narrow and would apply a high localised pressure to the beam 8. With these factors in mind, alternative designs to those illustrated in Figs. 1 to 3 might be preferred and one such alternative design is illustrated in Figs. 4 and 5.

Referring to Figs. 4 and 5, the illustrated tool comprises a tubular handle 11 which is a force fit into a socket 12 defined by a one piece cast tool head. The tool head comprises a cross member 13, a pair of levers 14 defining nail-removing slots 15, a hammer head 16 defined by one end of the cross member 13, and a spike 17 defined by the other end of the cross member 13. The levers 14 may be~useαTto lever a batten from the beam in exactly the same manner as described with reference to Figs. 1 to 3. In addition the hammer head 16 may be used to drive nails home and the spike 17 may be used to form nail holes .in slates. Thus, a single robust tool can be used to perform all of the functions required by a worker stripping and repairing roofs of various types.

With the alternative arrangement of Figs. 4 and 5 it will be noted that the cross member 13 is generally cylindrical and accordingly it defines a rolling fulcrum which will apply less force to the surface upon which it is supported than the relatively narrow edge 5 of the embodiment of Figs. 1 to 3. This reduces the chances of damage to the underlying structure, particularly if that underlying structure includes roofing felt or a similar waterproof membrane. It will also be noted that the ends of the levers 14 curve slightly in the opposite direction to the main body of the levers 14. This reduces the tendency for the levers to dig into a batten beneath which they are positioned.

Although the present invention has been described with particular reference to problems arising in stripping roofs, it will be appreciated that the described tool is equally useful in other applications, for example lifting floorboards nailed to floor joists.

The configuration of a tool head according to a preferred embodiment of the invention is illustrated in Figs. 6 to 9. Apart from detailed

SUBSTITUTE SHEET dimensional differences there are only two significant differences between the tool head of Figs. 6 to 9 and that of Figs. 4 and 5 (the same reference numerals will be used for corresponding components where appropriate). Firstly, the spike 17 has been omitted from the tool head. This both reduces the cost of manufacturing of the tool head and significantly reduces its weight thereby increasing its utility. Secondly, only one of the levers 14 is provided with a nail-removing slot 15. This again significantly reduces the cost of manufacture of the tool head. There is no disadvantage in this arrangement given that even if a slot 15 was defined by each lever 14, only one such slot could be used to remove a nail at any given time.

A simplified modification of the tool head of Figs. 6 to 9, which is even cheaper to manufacture, is illustrated in Figs. 10 and 11. The only difference between this tool head and that shown in Figs. 6 to 9 is the omission of the hammer head 16.

SUBSTITUTE SHEET

Claims

1. A tool for levering a member from a beam to which the member is secured and across a width of which a member extends, comprising two levers, a cross member interconnecting the two levers, and a handle extending from the cross member, the levers being spaced apart and arranged such that they may be positioned beneath the member on opposite sides of the beam with the cross member resting on the beam to define a fulcrum about which the tool may be rotated to bring the levers into contact with the member.

2. A tool as claimed in claim 1, wherein the levers are defined by two arms extending from a sheet metal component secured to the handle.

3. A tool as claimed in claim 1, wherein the levers are defined by elements of a cast head to which a handle has been secured -

4. A tool as claimed in any preceding claim, wherein a hammer head is defined at one end of the cross member to enable its use as a simple hammer.

5. A tool as claimed in any preceding claim, wherein a spike is secured to one end of the cross member.

6. A tool as claimed in any preceding claim, wherein one or each of the levers defines a longitudinal slot opening to its end.

7. A tool substantially as hereinbefore described with reference to the accompanying Figs. 1 to 3, 4 to 5, 6 to 9 or 10 to 11.

SUBSTITUTE SHEET