EP2388406A2

EP2388406A2 - Roof scaffold

Info

Publication number: EP2388406A2
Application number: EP11166384A
Authority: EP
Inventors: Erik Nykvist; Johan Höcks
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-17
Filing date: 2011-05-17
Publication date: 2011-11-23
Also published as: EP2388406A3; SE535017C2; SE1050479A1

Abstract

Roof scaffold (10) adapted to be arranged to an upwardly directed flange on a roof, the flange having a first and a second side (13,14). The roof scaffold (10) comprises a roof part (20) adjustably arranged to a work port (50), and adapted to bear against a roof surface (12) after mounting. The roof part (20) comprises a coupling arrangement (30) for releasable attachment of the roof scaffold (10) to the flange (11). The coupling arrangement (30) comprises at least a first and a second coupling member (31,32) arranged to cooperate with each other and in a direction opposing each other on each side of the flange (11) with a force (F1,F2) so that the coupling arrangement (30) is retained to the flange (11). The force (F1,F2) arises as a function of gravity. The work part (50) has a work surface (51) for carrying a load, or for work. The force (F1,F2) is imparted via the roof part to the first and the second coupling member in a direction parallel to the roof surface (12).

Description

TECHNICAL AREA

The present invention relates to a roof scaffold specifically adapted to roofs having flanges such as tin plated roofs. The roof scaffold comprises an improved coupling arrangement to connect the roof scaffold to the flange of the tin plated roof.

BACKGROUND

To perform work on a roof, such as maintenance or assembly of the roof, can be just as dangerous as difficult. As roofs generally are inclining there is a risk that the worker may slip and in a worst case scenario hurt himself. It is also difficult to handle equipment on inclining roofs.
In the published patent documents WO 03/100181 A2 and US 789,034 , this has been solved by a scaffold which can be connected to one or more flanges which extend from the surface of the roof. However, the described solutions have some flaws.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved roof scaffold which enables a secure attachment to a flange on a roof, e.g. a tin plated roof. This is solved with a roof scaffold adapted to be arranged to an upwardly directed flange having a first and a second side. The roof scaffold comprises a roof part adjustably arranged to a working part. The roof part is adapted to be positioned adjacent a roof surface after being mounted. Said roof part comprises a coupling arrangement for releaseably connecting the roof scaffold to the flange. The coupling arrangement comprises at least a first and a second coupling member arranged to cooperate with each other and in a direction towards each other on each side of the flange with a force enabling the coupling arrangement to be connected to the flange, whereby the force arises as a function of gravity. The roof part comprises a working area for carrying a load or for work. Said force is transferred via the roof part to the first and second coupling member in a direction parallel to said roof surface.
The present invention provides a safe coupling arrangement with few movable parts and which connects to only one flange. This avoids the drawbacks with using two neighboring flanges which run the risk of bending or being deformed, while at the same time providing a good force transfer to the flange. A large contact surface with the flange can be used.
The above mentioned force can be said to be a first and a second force in a direction opposing each other.
According to an aspect of the present invention, the roof part disclose a first and a second longitudinal bar wherein the first coupling member is arranged to the first longitudinal bar and the second coupling member is arranged to the second longitudinal bar. This provides for a good force transfer between the roof part and the coupling members of the coupling arrangement.
Preferably the first and the second coupling members each have a substantially oblong shape. With a substantially oblong shape, a large contact surface can be provided which enables a high friction between the contact surface and the flange. The oblong coupling members present a first and a second short side, wherein the proximity to the first and the second short side a coupling bar (33a, 33b, 35a, 35b) is pivotally arranged to the first and the second longitudinal bar (23, 24). This provides for a robust coupling arrangement which can withstand high forces and provide high friction between the surfaces concerned.
According to an aspect of the present invention, the sum of the lengths of the first coupling bars is longer than the length of said first transverse bar of the roof part. The roof scaffold will thus not, without substantial deformation or breaking, accidentally come loose from the flange. In the same manner, the sum of the lengths of the second coupling bars may be longer than the length of the first transverse bar of the roof part. This further prevents the roof scaffold from accidentally coming loose from the flange without substantial deformation or breaking.
According to an aspect of the present invention, the first and the second coupling members each comprise a substantially rectangular contact surface adapted to be positioned adjacent the flange after mounting. This provides for a relatively large contact surface. The contact surface may for example be 5-40 cm², preferably 5-30 cm², most preferably 8-25 cm². In an embodiment, the area of the contact surface is 5-40 cm², preferably 5-30 cm², most preferred 8-25 cm² independently of the shape of the contact surface. In an embodiment, the first and the second coupling member present an extension towards the flange which is 5-40 cm², preferably 5-30 cm², most preferably 8-25 cm².
The roof part may present a first and a second transverse side, a first and a second longitudinal side, wherein the work part is pivotally arranged to the roof part in connection with the first transverse side of the roof part, for example through a hinge or through a flexible but durable material, such as leather or a fiber cloth.
At least one adjustment bar extends between the roof part and the work part, preferably two, for adjusting the angle between the roof part and the work part.
The first and the second longitudinal sides of the roof part is in one embodiment formed by a first and a second longitudinal bar, and the mentioned first and second transverse sides of the roof part is formed by a first and a second transverse bar. The first and the second longitudinal bar each have a contact surface adapted to be positioned adjacent the roof surface, and an opposing upper side. The first and the second transverse bar are arranged to, and bearing against, the upper side of the first and the second longitudinal bar. The roof scaffold can thus easily be positioned above the flange during mounting to the roof surface.
The roof part and the work part are according to one aspect of the invention arranged at an angle, and fixed to each other during said force transfer via the first and the second coupling member.

SHORT DESCRIPTION OF THE FIGURES

With reference to the accompanying figures, the invention will be described in greater detail in which;

figure 1 shows a roof scaffold according to one embodiment of the present invention after being mounted to a roof;
figure 2 shows the roof scaffold from figure 1 with a view in perspective;
figure 3 shows the roof scaffold of figure 1 with a view form the side and;
figures 4a-4b show parts of the roof scaffold of figure 1 and the function of the coupling arrangement.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows a roof scaffold 10 according to the present invention onto which a worker can sit during work. The roof scaffold 10 is specifically adapted to be connected to an upwardly directed flange 11, also referred to as a fold, which are common on tin plated roofs. The flange 11 extends from a roof surface 12 and connects two tin parts of the tin plated roof. The roof scaffold enables a comfortable work posture for the worker sparing joints and knees of the worker but may also be used as a surface for carrying a load such as tools or materials.
Figure 2 shows the roof scaffold 10 which comprises a roof part 20 and a work part 50. The roof part has a first and a second transverse bar 21, 22, a first and a second longitudinal bar 23, 24 which have a substantially rectangular cross section. However, the cross sections may be quadratic, circular or have any other suitable shape. The first and the second longitudinal bars 23, 24 each have a contact surface 25, an upper side 26 and an inner and outer side 27, 28. The contact surface 25 is adapted to bear against the roof surface 12. The first and the second transverse bar 21, 22 bear against the upper side 26 of the first and the second longitudinal bar 23, 24 connecting these to provide the roof part 10. The flange 11 of the roof may thus run freely beneath the first and the second transverse bar 21, 22. The flange 11 presents a first and a second side 13, 14. After being mounted, the first side of the flange 11 faces the first longitudinal bar 23, and the second side 14 of the flange faces the second longitudinal bar 24 of the roof part 20, as shown in figure 2.
The roof part 10 has a coupling arrangement 30 which is arranged to releasably connect the roof scaffold to the flange 11. The roof scaffold 10 attaches primarily to one flange 11 but it is conceivable that there is a plurality of coupling arrangements attaching to the same or to other flanges of the roof surface 12. The coupling arrangement 30 comprises a first and a second coupling member 31, 32. The couplings members 31, 32 are pivotally connected to the roof part 20.
In cases where one coupling member is described, it is within the boundaries of the invention that also the other coupling member 32 presents the same features, as can be seen in figure 2. The first coupling member 31 is pivotally arranged to the first longitudinal bar 23 of the roof part 20 via a first and a second coupling bar 33a, 33b. The first and the second coupling bars 33a, 33b are pivotally connected to both the first longitudinal bar 23 and the coupling member 31 so that the coupling member 31 can be pivoted without changing the angle of the contact surface 34 of the coupling member significantly.
The contact surface 34 of the coupling member 31 is thus substantially parallel to the inner side 28 of the first longitudinal bar 23. In the same manner, the second coupling member 32 is pivotally connected to the second longitudinal bar 24 of the roof part 20 via a first and a second coupling bar 35a, 36b. The first and the second coupling bars 35a, 35b are pivotally connected to both the second longitudinal bar 24 and the coupling member 33 so that the coupling member 32 can be pivoted without changing the angle of the contact surface 37 of the coupling member us changed. The contact surface 37 of the coupling member 32 is thus substantially parallel with the inner side 28 of the second longitudinal bar 24.
The first and the second coupling members 31, 32 each present a substantially oblong shape and have, as mentioned, a contact surface 34, 37 which is intended to be positioned adjacent the first and the second side 13, 14 of the flange 11. The contact surfaces 13, 14 preferably consist of a rubber material such as natural rubber or synthetic rubber. A friction enhancing material is advantageously used as contact surface 34, 37. The contact surfaces 34, 37are preferably substantially flat between the transverse ends. The contact surfaces 34, 37 present an area of 5-40 cm², preferably of 5-30 cm², most preferably of 8-25 cm².
A spring (not shown) is preferably arranged between the first and the second coupling member 31, 32. The spring acts upon the first and the second coupling member 31, 32 so that these are pulled towards each other. As an alternative, a spring may be arranged between the first coupling member 31 and the first longitudinal bar 23, and a spring may be arrange between the second coupling member 32 and the second longitudinal bar 24 so that the first and the second coupling member 31, 32 is drawn towards each other. As an alternative, the spring may be arranged to the first transverse bar 21. Instead of a spring, a contractive arrangement, e.g. an elastic element such as a rubber band or the like, can be used.
The work part 50 presents a work surface 51. The work surface 51 can be used for putting tools on, to stand on, or to connect other work scaffolds to it. In the shown embodiment in figure 2, the work part 50 is made up of a board with approximately 0.1-0.4 m², preferably approximately 0.2-0.3 m². The work part 50 has a substantially rectangular frame 52 to which a board 53, which defines the work surface 51, made of e.g. wood is arranged. A frame 52 also forms a step 54 as a result from the board 53 being arranged at a distance from the transverse side 55 of the frame 52.
Between the roof part 20 and the work part 50 at least one adjustment bar 60, 61 extends for adjusting and/or fixing the angle α between the roof part 20 and the work part 50. The embodiment in figure 2 shows a first and a second adjustment bar 60, 61 by which the angle α can be adjusted by changing the length of the first and the second adjustment bar 60, 61. The angle can preferably be adjusted so that the work part 50 with its work surface 51 is substantially horizontal. It should be noted that the work part 50, with the work surface 51, is fixed to the roof part 20 after being mounted and after the angle has been adjusted to the desired value. The transmission of force imparted by the coupling arrangement 30 is fully imparted despite that the work part 50, with the work surface 51, is fixed to the roof part 20.
Figure 3 shows the roof scaffold 10 with the view from the side. The flange 11 which extends from the roof surface 12 is specifically shown. The roof part 20 is resting on the roof surface 12. The short side of the first and the second transverse bar 21, 22 can be seen positioned on the upper side 26 of the second longitudinal bar 24 thus extending across the flange 11.
The function of the coupling arrangement will be described below. When the roof scaffold 10 has been positioned on the roof surface 12 and the coupling arrangement 30 has been coupled to the flange 11, the coupling arrangement 30 retains the roof scaffold to the flange 11 so that the position of the roof scaffold on the roof surface is maintained. The roof scaffold acts with a force mg, visualized with the arrow mg which illustrates the mass times gravity in figure 3. The force mg may of course be increased by placing a weight onto the work surface 51, e.g. by a worker whom positions himself onto the work surface 51. The force mg together with the roof surface 12 act upon the roof scaffold 10 with a force F, the roof scaffold strives to move in the direction of the force F, i.e. downwards from the roof due to the inclination of the roof.
The figures 4a-4b show how the force F acts on the roof part 20. For the sake of clarity, some parts have been removed from the roof scaffold 10. When the force F acts upon the roof part 20, a motion is transferred to the coupling arrangement 30, unless the coupling arrangement already is retained to the flange 11, e.g. via a contractive arrangement as mentioned above. The downwardly directed force F in turn provides for twin forces F1, F2 directed inwardly, which press the contact surfaces 34, 37 of the first and the second coupling members31, 32 against the first and the second side13, 14 of the flange 11. The forces F1, F2 are parallel with the roof surface 12 and thus transfer the downwardly directed force F in a very efficient way and without the need for moving the work part 50 with respect to the roof part 20.
As is noted in figure 4a, the first coupling member 31 is pivotally connected to the first longitudinal bar 23 and the second coupling part 31 is pivotally connected to the second longitudinal bar 24. In an embodiment, if the coupling members 31, 32 are connected to the first and the second longitudinal bars 23, 24 at only one pivot point, the distance between that pivot point and the first transverse bar 21 of the roof part 20 is less than the distance between the first transverse bar 21 of the roof part 20 and the pivot point of the coupling member.
In the embodiment shown in figures 4a-4b, the coupling members 31, 32 are arranged to the first and the second longitudinal bar 23, 24 via the coupling bars 33a, 33b, 35a, 35b, each via a first and a second pivot point 71, 72. The first and the second coupling member 31, 32 are connected to the coupling bars 33a, 33b, 35a, 35b via a third and a forth pivot point 73, 74. In this embodiment, the distance between the first transverse bar 21 of the roof part 20 and the first and the second pivot point 71, 72 is less than the distance between the first transverse bar 21 of the roof part 20 and the third and the forth pivot points 73, 74. The above mentioned distances are indicated in figure 4b with dashed lines.
The length of the first coupling bars 33a, 35a are together longer than the length of the first transverse bar 21 of the roof part 20. The length of the second coupling bars 35a, 35b are together longer than the length of the first transverse bar 21 of the roof part 20. This provides for a good force transfer to the flange 11 which retains the roof scaffold in its position. In practice, it is very difficult by applying pressure to make the coupling arrangement 30 slip from high load, without the material cracking or breaking.

Claims

A roof scaffold (10) adapted to be arranged onto a roof having an upwardly directed flange (11) with a first and a second side (13, 14), said roof scaffold (10) comprising a roof part (20) adjustably arranged to a work part (50), and after being mounted, adapted to bear against a roof surface (12), said roof part (20) comprising a coupling arrangement (30) enabling a releasable connection of said roof scaffold (10) to said flange (11), said connection arrangement (30) comprises at least a first and a second coupling member (31, 32) arranged to cooperate with each other and in a direction towards each other on each side of said flange (11) with a force (F1, F2) so that said coupling arrangement (30) is connected to said flange (11), wherein said force (F1, F2) arises as a function of gravity,
said work part (50) presenting a work surface (51) for carrying a load or for work, characterized in that
said force (F1, F2) is imparted to said roof part (20) to said first and second coupling member (31, 32) in a direction parallel with said roof surface (12).
The roof scaffold according to claim 1, characterized in that said roof part (20) present a first and second longitudinal bar (23, 24) wherein said first coupling member (31) is arranged to said first longitudinal bar (23) and in that said second coupling member (32) is arranged to said second longitudinal bar (24).
The roof scaffold according to claim 2, characterized in that said first and second coupling member (31, 32) each have a substantially oblong shape with a first and a second short side, wherein a coupling bar (33a, 33b, 35a, 35b) is pivotally connected in the proximity of said first and second short side and to said first and second longitudinal bar (23, 24).
The roof scaffold according to claim 3, characterized in that the sum of the lengths of said first coupling bars (33a, 35a) is longer than the length of said first transverse bar (21) of said roof part (20).
The roof scaffold according to claim 3 or 4, characterized in that the sum of the lengths of said second coupling bars (33b, 35b) is longer than the length of said first transverse bar (21) of said roof part (20).
The roof scaffold according to any of the preceding claims, characterized in that said first and second coupling member (31, 32) each comprises a substantially rectangular contact surface (34, 37) adapted to bear against said flange (11) after mounting.
The roof scaffold according to claim 6, characterized in that said substantially rectangular contact surface (34, 37) has an area of 5-40 cm², preferably of 5-30 cm², more preferably of 8-25 cm².
The roof scaffold according to any of the preceding claims, characterized in that said roof part (20) has a first and a second transverse side (21, 22), a first and a second longitudinal side (23, 24), wherein said work part (50) is pivotally arranged to said roof part (20) in the proximity of said first transverse side (21) of said rood part (20).
The roof scaffold according to claim 8, characterized in that between said roof part (20) and said work part (50) at least a first adjustment bar (60, 61) extends for adjustment of the angle (α) between said roof part (20) and said work part (50).
The roof scaffold according to claim 8 or 9, characterized in that said first and second longitudinal side (23, 24) of said roof part (20) consists of a first and a second longitudinal bar (23, 24), and in that said first and second transverse bar (21, 22) of said roof part (20) consist of a first and a second transverse bar (21, 22), wherein said first and second longitudinal bar (23, 24) each has a contact surface (25) adapted to be positioned adjacent said roof surface (12), and an opposing upper surface (26), wherein said first and second transverse bar (21, 22) are arranged to and bear against said upper side (26) of said first and second longitudinal bar (23, 24).
The roof scaffold according to any of the preceding claims, characterized in that the roof part (20) and the work part (50) are arranged at an angle (α) and are fixed to each other during said force (F1, F2) transfer.