MODULAR WORKING PLATFORM MOVABLE WITH HOISTING CABLES

Abstract

 The invention concerns a working platform that is movable with hoisting cables. The working platform comprises interlocking U-shaped elements (1) which are guidable with clutches (8) and corresponding openings (A) and arranged to be fastened with fasteners (11) wherein the elements (1) form a floor and a body (7) of the working platform.

Description

FIELD OF THE INVENTION

[0001] The invention relates to a modular working platform according to the preamble of claim 1.

BACKGROUND OF THE INVENTION

[0002] Mobile working platforms are often used in maintenance and repair work of buildings' exterior faces. The working platforms are usually made of aluminium including guardrails and hoisting points for hoisting devices. Typically guardrails and floor have been welded into a single structure. Working platforms are designed to have more length than width. Small working platforms that are designed for one person can also have a quadratic form. While working on an exterior face of a building, all the work is performed only on one side of the working platform. The working platform is moved in vertical direction with one or more hoisting devices. Industrial plants, such as power plants, pulp and paper mills, chemical plants, have large vessels and boilers which must be serviceable and inspectable from time to time from the inside. Entry to the inside of the vessels and boilers is usually only possible through a small manhole. Often the manhole has to be located at the topmost part or at a junction of wall and roof of the vessel or boiler for reaching optimal technical structure. A safe way to move up and down next to the walls inside the vessel or boiler must be arranged in order to inspect the vessel or boiler.

[0003] In order to transport a working platform through a manhole of 450 by 450 mm, the working platform has to be built from components that fit through the manhole. One solution like this is disclosed in US patent 4733896. In that document working platform is used for building a scaffold inside a boiler. Building requires transporting a lot of equipment and small components through the manhole. The vessels are typically round. In US patent 3907066 is disclosed a solution in which wing sections of a working platform can be pivoted for positioning close to walls. This kind of solution is not transportable through a manhole. A solution is disclosed in US patent 5579866. In that patent, floor can be folded from the middle in to two parts and the both halves are locked together with a connecting bar. Rectangular working platforms can be built that way. US patent 5007501 presents a solution for a rectangular working platform for a boiler-furnace. In that patent, parts that fit through a manhole are locked to each other with pins. Claims define that the manhole has to be located at the bottom. DE patent 3933865 presents a working platform having inflatable toroidal rings for round vessels. This device depends on dimensions of the vessel and is difficult to transport through a manhole.

BRIEF DESCRIPTION OF THE INVENTION

[0004] An object of the present invention is to eliminate disadvantages of the prior art. Especially an object of the invention is to present a new, modular working platform which is easy to assemble, easy to transport through a manhole, having a structure with minimal number of parts. The structure can also be easily modified for various sizes of vessels and boilers. It is also inexpensive to produce as it does not have special components. It offers simultaneous access to all walls of a vessel thus facilitating inspections and maintenance work.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] In the following the invention will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which

Figure 1 illustrates an annular working platform having more than one hoisting device and which can be used in round vessels;

Figure 2 illustrates an annular working platform having a single hoisting device;

Figure 3 illustrates a rectangular working platform which can be used in boiler-furnaces or similar vessels;

Figure 4 illustrates a modular element in detail;

Figure 5 illustrates a structure of a guard rail; and

Figure 6 illustrates a detail of the element according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0006] An annular working platform is presented in Figure 1. A floor is made of elements (1) each having same width and height. The elements (1) are dimensioned to fit through a manhole. The elements (1) are also light-weight such that a worker can move them by himself. The working platform can be raised and lowered with a hoisting device (2). An aperture (3) encased with guardrails is provided in the middle, which aperture is used for hoisting supplies and tools on the working platform. Guardrails (4) having variable dimensions and including baseboards according to regulations are surrounding the working platform. Apertures in the floor which facilitate fastening of the elements are covered with plates (5). Plates (5) may also serve as non-skid devices. Movement of the working platform is controlled with wheels (6) leaning on the walls.

[0007] An annular working platform is presented also in Figure 2. With a small enough load, the working platform can be raised and lowered with a single hoisting device (2) located in the middle.

[0008] A rectangular working platform is presented in Figure 3. The floor is made of elements (1) each having same width and height, as in Figure 1. The working platform is raised and lowered with a hoisting device (2). The working platform is equipped with guard rails (4). Apertures in the floor are covered with plates (5).

[0009] A typical element is presented in Figure 4. A U-shaped plate forms a body (7). Clutches (8) have been fixed to the body for facilitating fastening to another element. Openings (A) are provided for clutches of the opposite element. The sides have holes (B) for fasteners (11). In order to fasten the fasteners (11), the body (7) has apertures (C) on the top surface. The apertures (C) also serve the purpose of fixing the hoisting device. The apertures (C) are covered with plates (5) if necessary. Plates (5) also serve as non-skid devices. Tubular inserts (10) have been fixed to an end face (9) for attaching the guardrails.

[0010] Figure 5 illustrates structure of the guardrail (4). Parts (12) and (13) are tubular halves of the guardrail sliding inside each other like a telescope. The baseboards (14) are also adjustable. It has a groove (D) in the middle, from which the halves are attached to each other with a fastener (15). A tube (16) in inserted onto the guardrail half (13) having smaller diameter so that it can be easily attached to the elements (1).

[0011] Referring back to Figure 4, the element (1) has a substantially flat top surface having apertures (C) which can be covered with plates (5). The top surface forms the floor of the working platform so the top surface is in horizontal plane. On two opposing sides of the top surface are side surfaces which are parallel to each other and perpendicular to the top surface. In the same context the side surfaces are thus in vertical planes. For increased rigidity the free ends opposing the connecting edges of the side surfaces and the top surface are preferably bent inwards towards each other to form bottom lips of the element. Both bottom lips are in the same horizontal plane, parallel to the top surface and perpendicular to the side surfaces. Finally, an end face can be formed to one or two edges of the top surface that do not form an edge with any side surfaces. The end face in a vertical plane is perpendicular to the vertical planes of the side surfaces and also perpendicular to the horizontal planes of the top surface and the bottom lips. In case of two end faces, the two end faces are parallel and on opposite edges of the top surface. The described structure is rigid and can bear high loads compared to its own weight. The load bearing capacity can be increased by increasing height of the side walls which has only a small impact on the total weight of the element and the size of the manhole rarely limits the desired side wall height. An increase in thickness of the used material also increases the load bearing capacity but the impact on the total weight is more substantial.

[0012] The element is preferably made of a metal sheet by bending. Thickness of the material can be chosen based on e.g. required structural strength, dimensions of the element and material of the element. The elements form both the floor of the working platform and the body of the working platform so a separate load-bearing structure is not needed. The elements as such serve as the load-bearing structure or in other words the primary structure. This facilitates assembling of the working platform, especially in challenging conditions, as a single element as such can be used as a working platform and more elements can be fastened to that first element when needed.

[0013] The working platform is assembled by fastening a number of these elements (1) together. The side surfaces have holes (B) for receiving fasteners (11) for fastening two adjacent elements to each other. There are numerous ways to fasten the elements. A simple way is to use a bolt through holes (B) of two adjacent elements (1) secured and fastened with a nut. In an embodiment at least a part of the holes (B) are threaded for receiving a bolt therein. For example all holes on certain side surface can be threaded and the holes on the opposing side surface are non-threaded. In an embodiment the holes in the side surfaces may be unthreaded but half of the holes have a nut fixed on the inner side surface for receiving a bolt. Reinforcing plates having threaded holes can also be fixed to the inner side surfaces instead of nuts. Use of threaded holes or threaded parts fixed to the inner side surfaces reduces the number of fastener parts and facilitates the building of the working platform. However, a threading pattern has to be designed such that a threaded hole is always next a non-threaded hole when placing two elements adjacent to each other. For example a particular side surface may have all holes threaded and the opposing side surface has only non-threaded holes in all elements.

[0014] The fastening of elements is difficult if the working platform is assembled on an uneven surface or in the air hanging on hoisting cables, as the holes of adjacent elements have to be aligned in both vertical and horizontal direction. To facilitate the aligning of the elements and holes thereof, the elements are provided with protruding clutches (8) and corresponding openings (8A) for receiving said clutches. When placing a second element adjacent to a first element, the clutches of the first element are inserted in the openings of the second element or the clutches of the second element are inserted in the openings of the first element. Various designs can be used in clutches and openings. In an embodiment the clutches are L-shaped protrusions forming a gap between a part of the clutch and a side surface of the element. Width of said gap is at least the same as the thickness of a side wall, the side wall being beneath the side surface. The clutches (8) and corresponding openings (8A) are preferably located at or near the edges connecting the top surface and a side surface. The clutches (8) and corresponding openings (8A) can also be located on side surfaces between the edges which connect a bottom lip to a side surface and the top surface to the same side surface. The clutches (8) and corresponding openings (8A) can also be located at or near the edges connecting a bottom lip and a side surface. A clutch and opening pattern has to be designed such that a clutch always enters an opening when placing two elements adjacent to each other. For example a particular side surface may have only clutches and the opposing side surface has only openings for receiving clutches in all elements. Depending on the location and orientation of the clutch, a new element may be brought adjacent to an element of an assembled working platform from slightly above or below the horizontal plane defined by the top surfaces of the elements of the assembled platform. As the clutches of the element of the assembled platform enters the opening of the new element or vice versa, the top surfaces of all elements are aligned thereby locking the side wall to the gaps formed by the clutches of the new element or the element adjacent to it in the assembled platform. Now the holes in the side surfaces of these adjacent elements are aligned and fastening the adjacent elements to each other is fast and easy.

[0015] Figure 6 illustrates a detail of the element (1) according to an embodiment of the invention. According to the embodiment, clutch inserts (17) can be attached to the body (7) to provide the clutches. The body of the element has openings which are arranged to receive the clutch insert from inside the element by inserting the clutch insert (17) between the top surface and bottom lip of the element such that the clutch of the clutch insert protrudes from the body. The clutch insert is preferably arranged to stay in place by means of friction or one or more recesses or notches provided on the bottom lip. The same openings are also arranged to receive the clutch of a clutch insert inserted within an adjacent element such that adjacent side walls of the adjacent elements are aligned in both vertical and horizontal direction. Then fasteners (18, 19) such as a bolt and a nut can be used for fastening the aligned adjacent elements together, including the clutch insert. Fastener parts (18) such as nuts or threaded inserts can be fixed to the clutch insert or a threaded hole can be provided so that the fasteners have to be accessed only from the element receiving the clutch of the adjacent element. Use of clutch inserts (17) instead of fixed clutches gives more freedom in assembling the working platform and simplifies the production of the element bodies.

[0016] It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. A working platform movable with hoisting cables, the working platform being characterized in that it comprises interlocking U-shaped elements (1) which are guidable with clutches (8) and corresponding openings (8A) and arranged to be fastened with fasteners (11) wherein the elements (1) form a floor and a body (7) of the working platform.

2. A working platform according to claim 1, characterized in that apertures (C) are provided on a top surface of the elements (1) for fixing a hoisting device and for facilitating fastening of the fasteners (11).

3. A working platform according to claim 2, characterized in that said apertures (C) are covered with plates (5) which also serve as non-skid devices.

4. A working platform according to any one of claims 1 to 3, characterized in that guardrails (4) are made of pipes (12, 13) sliding into each other in telescopic manner and of staggered plates (14) having a groove for fastening them, which plates (14) serve as baseboards.

5. A working platform as claimed in any one of claims 1 to 4, characterized in that the element comprises a top surface forming the floor of the working platform, two opposing sides parallel to each other and perpendicular to the top surface and bottom lips in the same horizontal plane, parallel to the top surface and perpendicular to the side surfaces.

6. A working platform as claimed in claims 5, characterized in that the element further comprises an end face at one or two edges of the top surface that do not form an edge with any side surfaces, the end face being perpendicular to vertical planes of the side surfaces and also perpendicular to horizontal planes of the top surface and the bottom lips.

7. A working platform as claimed in any one of claims 1 to 6, characterized in that holes (B) are provided on the sides of the elements (1) for fastening two adjacent elements to each other with fasteners (11, 18, 19).

8. A working platform as claimed in claim 7, characterized in that said clutches (8) and corresponding openings (8A) are arranged to guide adjacent elements such that said holes (B) provided on the sides of the elements (1) are aligned when clutches (8) of an element are introduced in the corresponding openings (8A) of an adjacent element.

9. A working platform as claimed in any one of claims 1 to 8, characterized in that said clutches (8) and corresponding openings (A) are provided within an edge of a side surface of the element.

10. A working platform as claimed in any one of claims 5 to 9, characterized in that said clutches (8) are provided by clutch inserts (17) which are arranged to be inserted within the element between the top surface and a bottom lip of the element such that the clutch of the clutch insert (17) protrudes from the body (7).

Drawing