AU2005282177A1 - Elevator cage and method for installing an elevator cage - Google Patents

Description

VERIFICATION OF TRANSLATION Patent Application In AusTRALIA Re: international Patent Application No. PCT/CH2005/000483: 1, ROBERT CHARLES JONES, of Sentib~hlstrasse 59, CH-6045 Meggen, Switzerland. hereby declare that 1 am conversant with the German and English languages and that I am the translator of the document attached hereto and certify that to the best of my knowledge and belief the following is a true and correct English translation of the specification contained In PCT Application No. PCT/CH2005/00048 3 . Signature of the translator .-L A A Date O 09 WO 2006/026873 1 PCT/CH2005/000483 Elevator Car and Method of Installing an Elevator Car The objects of the invention are an elevator car with a car platform which comprises several platform sections, and a 5 method of installing such an elevator car. A car platform forms the basic supporting structure of an elevator car. It must be sufficiently rigidly designed to withstand the static and dynamic stresses imposed by the 10 load in the car and by the other components of the car. The floor area of the car is related in a certain manner to the load in the car for which the elevator car is designed. From DE 31 34 764 a platform for an elevator car is known 15 which comprises at least two platform-sections which are made from relatively thin steel sheets. The two platform sections are placed next to each other along the length of the elevator car and fastened to each other by welding. To ensure the necessary rigidity of the car platform, i.e. to 20 sufficiently stiffen the platform-sections which overhang at the front and the back of, and are subjected to bending stresses by the load on, a car platform, its front and/or back ends are connected by tie-rods to vertical struts of a car frame. Cited as advantages of this method of 25 construction are ease of manufacture and a reduction in weight by comparison with car platforms made from rolled sections. A car platform manufactured according to the approach of DE 30 31 34 764 has certain disadvantages. Firstly, the published tie-rod connections between the vertical struts of the car frame and the front end and back end of the platform sections which are needed to stiffen the car platform are complicated to manufacture, require more installation time, 35 and increase the number of elevator components required. Secondly, the elevator cars of many modern elevators are constructed self-supportingly, i.e. they no longer have a WO 2006/026873 2 PCT/CH2005/000483 car frame to which the ends of the platform-sections could be fastened. The purpose of the present invention is firstly to create 5 an elevator car with a car platform comprising several platform-sections which does not require stiffening of the platform-sections by means of struts connected to other parts of the car, but which can nevertheless be manufactured with sufficient rigidity in lightweight manner 10 from relatively thin metal sheets. The second purpose is to define an efficient and material saving method of installing an elevator car according to the invention with a car platform comprising several 15 platform-sections. In an elevator car according to the invention with a car platform comprising several platform-sections, the first mentioned purpose is fulfilled in that on the upper surface 20 of the car platform, platform-edge sections are mounted which extend over, and are fastened to, the upper surfaces of all the platform-sections. An elevator car according to the invention has the 25 advantages that the platform-sections of its car platform can be manufactured in extremely lightweight manner and with simple forms from relatively thin metal sheets, since the platform-edge sections ensure the rigidity of the car platform along the length of the car which is necessary for 30 operation of the elevator. At the same time, the platform edge sections fulfill the function of fastening elements which fasten the car platform to the side walls of the elevator car. In doing so, in the normal case they form a visible and thus aesthetically satisfying transition 35 element between the car floor and the said side walls.

WO 2006/026873 3 PCT/CH2005/000483 The second aforesaid purpose is fulfilled by a method of installing a car platform comprising several platform sections in which the installation of the car platform takes place in the following steps: 5 - the several separate platform-sections of the car platform and two platform-edge sections are made ready at the factory; - the unassembled platform-sections are delivered together with the platform-edge sections to the installation site 10 of the elevator; - on assembly at the installation site of the elevator, the platform-sections of the car platform, which are delivered separated from each other, and the platform edge sections are joined by means of fastening elements 15 into a car platform, the platform-sections being aligned with each other and stiffened with the aid of the platform-edge sections. An operation 'at the factory' is understood to mean an 20 operation which takes place under factory-like conditions before shipment of the elevator and before its assembly at the installation site, i.e. for example in a suitable building and using especially suitable aids and equipment. 25 Advantages derive from the method according to the invention for installing an elevator car firstly in that through the use of rigid platform-edge sections, the car platform comprising several platform-sections is so strengthened that the platform-sections can be manufactured 30 with low weight and from relatively thin metal sheets. Transportation of the car platform to the installation site, and moving it into its installation position, for example in the elevator hoistway of a building, are thereby enormously facilitated. Secondly, when assembling the 35 elevator at the installation site, the lightweight platform-sections can be joined together into a car platform without great effort, since the platform-sections WO 2006/026873 4 PCT/CH2005/000483 are precisely aligned with each other practically of their own accord by the effect of the platform-edge sections. Advantageous embodiments and further developments of the 5 invention are described below. It is expedient for the platform-edge sections (8; 28) to be mounted in the area of two side-edges of the car platform (1; 21) lying opposite each other, so that the 10 available useable area of the elevator car is not restricted by their presence. Optimal conditions with regard to rigidity and weight of the car platform result when the cross section and material of the platform-edge sections are so selected that the 15 latter, without the assistance of other components, can absorb the bending stress which the load in the car exerts on the platform-sections projecting from a central platform-section and thereby undergo flexure of less than 1 % of the length of the platform-sections. 20 It is preferable for these properties of the platform-edge sections to be obtained by their being manufactured from steel or an aluminum alloy, and their having a cross section which relative to its horizontal axis of gravity 25 has a geometric moment of inertia of 50 cm' and/or an overall height of at least 6 cm. According to an especially preferred embodiment of the invention, the platform-edge sections which serve as 30 stiffening elements also form connecting elements by which the side walls of the elevator car are joined to the car platform. By means of this solution, a rigid connection is created between the side walls of the elevator car and the car platform, the combination of this function of the 35 platform-edge sections with their function as stiffening elements resulting in a considerable simplification of the WO 2006/026873 5 PCT/CH2005/000483 construction of the car platform and thereby in substantial cost savings. According to a further preferred embodiment of the elevator 5 car according to the invention, a front and a back platform-section are arranged on a central platform section. Thanks to this concept, the platform-sections can have different lengths and also different shapes so as to fulfill or simplify the realization of different functions 10 which are present in an elevator car. Important advantages derive from an embodiment of the invention in which the platform-sections of the car platform have fastening points arranged in parallel 15 vertical planes at which these platform-sections are additionally joined to each other with fastening elements, preferably with screwed fasteners. In this embodiment, the platform-sections are aligned relative to each other of their own accord when the fastening elements are tightened, 20 especially if the platform-edge sections are connected to the platform-sections at the same time. Furthermore, with this arrangement of the fastening points, the fastening elements are subjected to tension at the vertical fastening points if the fastening elements between the platform 25 sections and the platform-edge sections are subjected to shear, and vice versa, as a result of which, possible movement of the platform-sections relative to each other under load is reliably prevented. 30 Outstanding flexibility with regard to the manufacture of car platforms according to the invention is achieved by it being possible for the front and/or back platform-section to be executed as a single-part platform-section or to comprise several sub-sections. 35 A particularly inexpensive embodiment of a car platform according to the invention results if the platform- WO 2006/026873 6 PCT/CH2005/000483 sections, or sub-sections of the platform-sections, are executed as U-shaped bent-metal sections, each of which comprises one single piece of sheet metal. 5 According to a preferred embodiment of the method according to the invention, the platform-sections of the car platform are fastened to each other by means of fastening elements at fastening points arranged in parallel vertical planes. This has the advantage that the platform-sections are 10 aligned relative to each other of their own accord when the fastening elements are tightened. Furthermore, with this arrangement of the fastening points, at the vertical fastening points the fastening elements are subjected to tension when the fastening elements between platform 15 sections and the platform-edge sections are subjected to shear and vice versa. By this means, possible movement of the platform-sections relative to each other under load is reliably prevented. 20 According to a further advantageous development of the method according to the invention, assembly of the car platform at the installation site of the elevator comprises the following steps: - the platform-sections are lined up along the length of 25 the elevator car so that their respectively corresponding vertical fastening points lie opposite each other; - the platform-edge sections are laid on the upper surface of all the platform-sections and loosely fastened to the platform-sections by means of fastening elements; 30 - the fastening elements are passed through openings in the area of the vertical fastening points and, with the aid of the fastening elements and without tension, the platform-sections are laid against each other in the area of their vertical fastening points; 35 - the fastening elements are alternately increasingly tightened at the platform-edge sections and at the vertical fastening point, the platform sections being WO 2006/026873 7 PCT/CH2005/000483 thereby aligned of their own accord. As already described above, thanks to the combined fastening to platform-edge sections and vertical fastening 5 points, when the platform-sections are tightened they are aligned with each other in ideal manner of their own accord if the fastening elements at the fastening points involved are increasingly tightened alternately. 10 Following below, two exemplary embodiments of the invention are explained by reference to the attached drawings. Shown are in Fig. 1 an exploded-view drawing of a first embodiment of 15 the car platform of an elevator car according to the invention; Fig. 2 a side view of the car platform shown in exploded view in Fig. 1; 20 Fig. 3 a side view of a second embodiment of the car platform of an elevator car according to the invention; 25 Fig. 4 a view of the car platform according to Fig. 3 along its length and a cross section through the car platform. Fig. 1 shows in the form of an exploded-view drawing the 30 structure with all significant component parts of a first embodiment of the car platform 1 of an elevator car according to the invention. Fig. 2 shows in a side view the car platform 1 according to 35 Fig. 1 in assembled state.

WO 2006/026873 8 PCT/CH2005/000483 The car platform 1 comprises several platform-sections 2, 3, 4 which are made from steel sheet and steel plates, one front and one back platform-section 3, 4 respectively being arranged on a central platform-section 2. Fixed on the 5 upper surface of the platform-sections, which lie in a common plane, is a car-floor plate which is preferably executed as a laminated plate. Suitable as car-floor plate are preferably honeycomb sandwich plates of aluminum or plastics or wood-fiber boards with metallic laminates on 10 both sides. The central platform-section 2 takes the form of a safety plank of the elevator car which is built into the car platform. It provides the elevator car with the required rigidity, the space being saved which in normal elevator 15 cars is occupied by a safety plank present under, and not built into, the car platform. The central platform-section 2 forming a safety plank has, inter alia, fastening points 2.5, 2.6 for car guide shoes 20 and/or safety gear. Safety buffers can also be attached to this safety plank. Furthermore, built into the central platform-section 2 forming the safety plank are suspension and-return pulleys 11 over which a flexible suspension means supports and moves the elevator car. In the present 25 case, the suspension-and-return pulleys 11 have grooves and ribs running in the direction of the circumference which act in conjunction with ribs and grooves of V-ribbed belts serving as suspension means. 30 In the central platform-section 2 forming the safety plank, it is also possible for a safety-space protection device 12 to be built in. By laterally extending a bolting rod 12.1 which acts in conjunction with a stop fixed in the elevator hoistway, this ensures that, for example, on an inspection 35 trip a safety distance between the car roof and the hoistway headroom and/or between the car floor and the floor of the elevator hoistway cannot be passed.

WO 2006/026873 9 PCT/CH2005/000483 All of the platform-sections 2, 3, 4 each comprise at least two longitudinal supports 2.2, 3.2, 4.2, and at least one lateral support 2.3, 3.3, 4.3. The lateral support 2.3 is 5 part of the central platform-section 2 which forms a safety plank of the elevator car which is built into the car platform 1. The lateral support 3.3 serves as support for a door-sill section 7 (shown only in Fig. 2) as well as for supports 13 of a shear apron, and an upper part of the 10 lateral support 4.3 is so constructed that a car back wall (not shown) can be fastened to it. The platform-sections 2, 3, 4 have fastening points 2.1, 3.1, 4.1 lying in parallel vertical planes, at each of 15 which two of the platform-sections are fastened together by means of fastening elements 10. It is preferable for undoable fastening elements, as for example screw fasteners, to be used. Fastening of the platform-sections in the area of the said vertical planes can, however, also 20 be realized with other fastening elements as, for example, rivets or snappable fastening elements. In this fastening concept, when assembling the car platform at the installation site of the elevator, the respective 25 platform-sections to be joined are first roughly aligned with each other. Then, with the aid of the fastening elements, they are laid against each other in the area of the vertical fastening points, as a result of which the platform-sections align themselves with each other of their 30 own accord. The mutual alignment is aided by the simultaneous mounting of platform-edge sections which is described below. Referenced with 8 are two platform-edge sections which on 35 assembly at the installation site of the elevator are fastened to the platform-sections 2, 3, 4 at fastening points 2.4, 3.4, 4.4 of the latter, and extend in the area WO 2006/026873 10 PCT/CH2005/000483 of both side edges of the car platform 1 over the upper surfaces of all the platform-sections which are flanged together. The said fastening points on the platform sections are so arranged that, in the assembled state of 5 the car platform 1, they lie in a common horizontal plane. For the fastening between the platform-edge sections 8 and the platform-sections 2, 3, 4 it is preferable for undoable fastening elements, for example screwed fasteners, to be used. The fastening can, however, also be realized with 10 other fastening elements, for example with rivets or with positive-fit fastening elements. A positive-fit connection between the platform-edge sections 8 and the platform sections 2, 3, 4 could, for example, be achieved by means of snap fasteners. 15 The platform-edge sections 8 are so dimensioned that they make a substantial contribution to the rigidity of the entire car platform 1. It is advantageous for their material and cross section to be so chosen that together, 20 and without the involvement of other components, they can absorb the bending stress which the load in the car exerts on the platform-sections 3, 4 extending from the central platform-section 2 and thereby undergo flexure of less than 1 % of the length of the respective platform-sections. It 25 is preferable for this property of the platform-edge sections to be achieved by these being manufactured from steel or an aluminum alloy and having a cross section which relative to its horizontal axis of gravity has a geometric moment of inertia of at least 50 cm' and/or an overall 30 height of at least 6 cm. The platform-edge sections 8 serve firstly to stiffen the entire car platform 1 so that the requirements for rigidity of the platform-sections 2, 3, 4 can be correspondingly 35 reduced. These can therefore be produced with lower weight. In the present case, the platform-sections 3 and 4 are manufactured solely of steel sheet with a maximum thickness WO 2006/026873 11 PCT/CH2005/000483 of 2.5 mm. Secondly, the platform-edge sections 8 serve to join the (not shown) side walls of the car to the car platform 1 and thereby form a visible and aesthetically pleasing transition element between the car floor and the 5 said side walls of the car. During assembly at the installation site of the elevator, the platform-edge sections 8 also serve, with the aid of the fastening elements 14 in place between them and the 10 platform-sections, to align the upper surfaces of the platform-sections 2, 3, 4, which are flanged to each other, accurately and flush with each other. In and/or on the front and/or back platform-sections 3, 4, 15 car components such as, for example, a door-sill section 7, a mounting 13 for a shear apron under the door-sill section 7, a mounting element 4.3.1 for the back wall of the car, end-switches, terminal boxes for electrical systems, hoistway lighting lamps, etc. can be present. So that the 20 front and/or back platform-sections 3, 4 can fulfill these functions, they have correspondingly different shapes. The aforementioned components and subsystems (car guide shoes, safety gear, safety buffers, suspension-and-return 25 pulleys, safety-space securing device, shear apron, end switches, terminal boxes, etc.) which are built into, or onto, one of the platform-sections 2, 3, 4 are preferably pre-mounted, and preferably wired, at the factory, so as to keep the outlay for assembly at the installation site of 30 the elevator as low as possible and to optimize the quality of assembly. A car platform according to the invention constructed of several platform-sections offers ideal conditions for this assembly concept since firstly, the individual platform-sections to be transported and brought 35 into position for assembly are relatively easily manipulated even with built-in subsystems, and secondly, the still separate platform-sections can be better packed WO 2006/026873 12 PCT/CH2005/000483 so that the said components and subsystems are sufficiently protected. The longitudinal supports 3.2, 4.2 which define the lengths 5 L3, L4 of the respective platform-sections 3, 4, and the lateral supports 2.3, 3.3, 4.3 which define the width B of the platform-sections 2, 3, 4, are manufactured independent of each other and held in stock, the lengths L3 and L4, as also the width B of the platform-sections 2, 3, and 4, 10 corresponding to a modular dimension concept, being selectable. Preassembly at the factory of the platform sections takes place only on the basis of a concrete order with defined car dimensions by combining longitudinal and lateral supports with corresponding dimensions. 15 With this manufacturing and stocking concept, the costs of producing and stocking the car platforms can be kept extremely low while an optimal ability to supply remains assured. 20 Fig. 3 shows a side view of a second embodiment of a car platform 21 of the elevator car according to the invention. Fig. 4 shows a view of this car platform 21 in its longitudinal direction A and a cross section through the car platform at the interface indicated by II - II in Fig. 25 3. This embodiment of a car platform 21 according to the invention also comprises several platform-sections 22, 23, 24, one front and one back platform-section 23, 24 respectively being arranged on a central platform-section 30 22. The front and the back platform-sections 23, 24 are preferably constructed of several sub-sections 23a, 23b, 24a, 24b. The sub-sections 23a, 23b, 24a, 24b of the front and back platform-sections 23, 24 are executed as essentially U 35 shaped bent-metal sections and in each case made by parallel bending from one single piece of sheet metal. The vertically arranged webs of the U-shaped bent-metal WO 2006/026873 13 PCT/CH2005/000483 sections act not only as lateral stiffeners of the car platform but also form fastening points 22.1, 23.1, 24.1 arranged in vertical planes at which the sub-sections are joined to each other by means of fastening elements 30, and 5 which also serve as connecting points between the central platform-section 22 and the front and back platform sections 23, 24 respectively. Front and back platform sections of little length can also consist of only one single U-shaped bent-metal section. 10 As in the first embodiment, the central platform-section 22 is executed as a safety plank built into the car platform 21 and made solely of steel sheet. This platform-section 22 also has fastening points for car guide shoes and safety 15 gear, as does the safety plank shown in Fig. 1. These fastening points are not shown here, however, so as not to detract from illustration of the particularly simple structure of the platform-sections. 20 The front and back platform-sections 23, 24 can be of different shapes so as to fulfill different functions and requirements, or to allow different positions of the central platform-section. They can, for example, be so formed (bent) that they can accept a door-sill section 27, 25 or so that a fastening element 24b.1 for fixing the back wall of the car is built into their sheet-metal body. Different dimensions of the car platform 21 are realized by modifying the lengths L 23, L 24 of the platform-sections 23, 24, or their sub-sections 23a, 23b, 24a, 24b, which are 30 flanged to the central platform-section 22 (safety plank). Different widths B are achieved by using different widths of steel sheet for manufacturing the platform-sections 22, 23, 24, and 22, 23a, 23b, 24a, 24b respectively. 35 All the subsystems and components mentioned in association with the first embodiment can also be built into, or onto, the platform-sections 22, 23, 24 of this car platform 21, WO 2006/026873 14 PCT/CH2005/000483 building the subsystems into, or onto, the platform sections which are separate from each other taking place as preassembly at the factory. 5 As mentioned above, in this embodiment the platform sections 23, 24, or their sub-sections 23a, 23b, 24a, 24b flanged to the central platform-section 22, are each made from one single piece of sheet metal whose U-shaped form is produced by simple parallel bending. All the platform 10 sections and/or sub-sections have vertically oriented webs which run perpendicular to the car platform 21 and give the car platform in the perpendicular direction sufficient rigidity. So as to be able to additionally fix the free lower ends of the vertical webs, these can be joined to 15 each other by means of, for example, an auxiliary section 31. Mounting of this auxiliary section 31 only takes place at the installation site of the elevator. As is readily apparent from Fig. 3, the platform-sections, 20 which are constructed of sections made from relatively thin sheet metal bent crosswise, do not offer sufficient bending rigidity for a car platform in its longitudinal direction. Hence, in the embodiment of a car platform 21 described here, the rigidity in longitudinal direction required for 25 elevator operation is assured by mounting at the installation site in the area of the two opposite side edges of the car platform 21 two sufficiently rigid platform-edge sections 28 with which the upper surfaces, lying in a common plane, of all the platform-sections 22, 30 23, 24 are connected. In this embodiment also, the platform-edge sections 28 serve additionally as fastening element between the car side walls (not shown) and the car platform 21. So as to be 35 able to fasten the platform-edge sections 28, which here have a rectangular cross section, to both the platform sections 22, 23, 24 and the side walls, the platform-edge WO 2006/026873 15 PCT/CH2005/000483 sections 28 are provided along their entire length with several T-shaped grooves 32. When the car platform 21 is assembled at the installation site, screw heads or nuts of suitable shape are inserted into these T-shaped grooves 32 5 and bolted to the platform-sections and side walls. With the exception that in this second embodiment the platform-sections have no lateral supports, and that hence such lateral supports do not need to be separately 10 manufactured and held in stock, all of the properties and advantages of the car platform associated with the first embodiment, as well as the characteristics and advantages of the method of installing an elevator, also apply to the second embodiment described here.

Claims (11)

1. Elevator car with a car platform (1, 21) comprising several platform-sections (2, 3, 4; 22, 23, 24) 5 characterized in that over the upper surfaces of all the platform-sections (2, 3, 4; 22, 23, 24) platform-edge sections (8; 28) extend which are fastened to the platform-sections (2, 3, 4; 22, 23, 24). 10

2. Elevator car according to Claim 1, characterized in that the platform-edge sections (8; 28) are mounted in the area of two oppositely lying side edges of the car 15 platform (1; 21).

3. Elevator car according to claim 1 or 2, characterized in that the cross section and material of the platform-edge sections (8; 28) are so chosen that 20 they can absorb the bending stress which the load in the car exerts on the platform-sections extending beyond a central platform-section (2; 22) without the involvement of other components and thereby undergo a flexure of less than 1 % of the length of the platform 25 sections.

4. Elevator car according to one of claims 1 to 3, characterized in that the platform-edge sections (8; 28) consist of steel or an aluminum alloy and have a 30 cross section which, relative to its horizontal axis of gravity, has a geometric moment of inertia of at least 50 cm' and/or an overall height of at least 6 cm.

5. Elevator car according to one of claims 1 to 4, characterized in that 35 the platform-edge sections (8; 28) form a fastening element for fastening the side walls of the elevator WO 2006/026873 17 PCT/CH2005/000483 car to the car platform (1; 21).

6. Elevator car according to one of claims 1 to 5, characterized in that 5 arranged on a central platform-section (2; 22) are a front and a back platform-section (3, 4; 23, 24), it being possible for the latter to be of different shapes so as to be able to fulfill different functions which are present in an elevator car. 10

7. Elevator car according to one of claims 1 to 6, characterized in that at least two of the platform-sections (2, 3, 4; 22, 23, 24) have fastening points (2.1, 3.1, 4.1; 22.1, 23.1, 15 24.1) arranged in parallel vertical planes at which these platform-sections are fastened to each other by means of fastening elements (10; 30).

8. Elevator car according to one of claims 1 to 7, 20 characterized in that the front and/or the back platform-section (3, 4; 23, 24) is/are executed as single-part platform-sections or comprise several sub sections (23a, 23b, 24a, 24b). 25

9. Elevator car according to Claim 8, characterized in that the front and back platform sections (23, 24) and/or their sub-sections (23a, 23b, 24a, 24b) of the car platform (21) are executed as U shaped bent sections which each consist of one single 30 piece of sheet metal.

10. Method of installing an elevator which comprises an elevator car with a car platform (1; 21) made of several platform-sections (2, 3, 4; 22, 23, 24), 35 characterized in that the method comprises the following steps: - the car platform (1; 21), which is divided into WO 2006/026873 18 PCT/CH2005/000483 several platform-sections (2, 3, 4; 22, 23, 24), and two platform-edge sections (8; 28) are made ready at the factory; - the unassembled platform-sections (2, 3, 4; 22, 5 23, 24) are delivered to the installation site of the elevator together with the platform-edge sections (8; 28); - on assembly at the installation site of the elevator, the platform-sections (2, 3, 4; 22, 23, 24) of the 10 car platform (1; 21), which are delivered separated from each other, and the platform-edge sections (8; 28), are joined by means of fastening elements (10; 30) into a car platform (1; 21), the platform sections being precisely aligned with each other and 15 stiffened with the aid of the platform-edge sections.

11. Method according to Claim 10, characterized in that the platform-sections (2, 3, 4; 20 22, 23, 24) of the car platform (1; 21) are additionally joined to each other at fastening points (2.1, 3.1, 4.1; 22.1, 23.1, 24,1) arranged in parallel vertical planes. 25 Method according to Claim 11, characterized in that assembly of the car platform (1; 21) comprises the following steps: - the platform-sections (2, 3, 4; 22, 23, 24) are 30 placed next to each other in the longitudinal direction of the elevator car so that their corresponding vertical fastening points (2.1, 3.1, 4.1; 22.1, 23.1, 24.1) lie opposite each other; - the platform-edge sections (8; 28) are laid on the upper 35 surface of all the platform-sections (2, 3, 4; 22, 23, 24) and fastened loosely to the platform sections by means of fastening elements (10; 30); WO 2006/026873 19 PCT/CH2005/000483 - the fastening elements (10; 30) are inserted through openings in the area of the vertical fastening points (2.1, 3.1, 4.1; 22.1, 23.1, 24.1) and, with the aid of the fastening elements, the platform sections (2, 3, 4; 5 22, 23, 24) are laid against each other in the area of their vertical fastening points without pretensioning; - the fastening elements (14; 34, 10; 30) are alternately increasingly tensioned at the platform edge sections (8; 28) and at the vertical fastening 10 points (2.1, 3.1, 4.1; 22.1, 23.1, 24.1), the platform-sections (2, 3, 4; 22, 23, 24) being thereby aligned with each other of their own accord.