ARRANGEMENT OF A WORKING PLATFORM

Abstract: Description is given of an arrangement of a working platform (16) which is suspended in a superjacent support construction, such as a ceiling construction, tier of beams or the like, with the working platform (16) being connected to the support construction by being mounted to a yoke construction (26), and that the platform (16) is arranged so that it can be raised or lowered in relation to the yoke construction. The arrangement is characterized in that the yoke construction comprises one or more extendable rods (40, 42, 44, 46), and with a given force can be brought to abut a superjacent support construction (12, 14) to in this way stabilise the relative position of the yoke construction/platform.

Description: Arrangement of a worKir.g platform The present invention relates to an arrangement of a working platform wnich is suspended from an overhanging support construction, such as a ceiling construction, a tier of beams or the like, as the working platform is connected to the support construction via a mounting m a yoke construction, and that the platform is arranged so that it can be raised and lowered in relation to the yoke construction. The invention is particularly related to a platform system for internally suspended access to carry out various obs m large tanks, ashore and m ships and cargo holds m ships, and for example, under the deck on offshore installations. According to the invention the arrangement will m this way represent an alternative to scaffolding for such tasks. In large tanks and the like it is today necessary to erect scaffolding to carry out even the simplest safety inspections and/or performing normal maintenance. This leads to wasted production time with associated loss of income m addition to the expenses for the scaffolding and the work itself. Total costs are often not in relation to what is achieved by the work carπeα out. Regarding the state of art, reference is made to US Patent No. 3.602.335 and European Patent No. 3.982. US Patent No. 3.602.335 describes a platform from which one can carry out work on a construction, in this case an aeroplane. The platform is suspended from a superjacent construction with the a d of a strengthened vertical central arm. The suspension of the construction itself is achieved by a double set of rail pairs, so that the platform can be moved horizontally both m the X and Y directions. Since the platform also can be raised and lowered vertically, an operator on tne platform will have access to all parts of a relevant workspace, such as around an aeroplane that is placed m a hanger etc. as indicated by the drawings m the patent. European Patent 3 982 shows a working platform 20 whicn is suspended by wires or ropes. The platform itself can be raised or lowered and rotated around a central axis. However, tnere is nothing which can prevent the working platform from tipping over if the weight load becomes too large on one side, e.g. on the side where the person is standing, as the figure indicates. With the present invention, it is aimed to provide a completely new construction for suspension of working platforms, and wnich remedies the above mentioned disadvantages . Furthermore it is an aim of the invention to provide a construction wnich makes it possible to alter or extend the anchoring devices in the ceiling beam construction, without the operator having to leave the platform or basket . Thus, it is also an aim of the invention that the suspension is such that the rail in the ceiling construction which supports the whole construction can be added on (extended) by the operator without him having to leave the working basket. According to the invention there is consequently developed a platform system which gives full access to all areas, for example m tanks and cargo holds, and which is also very effective for use under rigging decks. The platform can rotate 360°. It can be driven horizontally and raised and lowered. Contrary to traditional scaffolding, the platform system can according to the invention be assembled quickly without any detriment to safety. According tc the invention the platform system comprises m its oasic form at least one suspension rail for fastening of a yoke construction via a suspension device around whicn the yoke construction can be rotated m the horizontal plane. Below, and secured to this yoke construction, the platform itself is suspended, m this way it can also ce rotated horizontally 360° around the suspension arrangement . The suspension arrangement comprises a runner for movement along the suspension rail . The flexible access in the vertical direction is made secure and simple by equipping the platform with a means of elevation for it to be raised/lowerd with respect to the suspension point on the suspension rail . According to the invention the yoke construction comprises a stabilisation device m the form of one or more extendable supporting devices, which, at a given force, can be brought to abut the superjacent support construction. In this way the yoke is stabilised and prevented from tilting vertically when the operator moves to one of the ends of the suspended platform. According to the invention the platform system is easy to assemble, it can easily be transported and is ideal for working operations sucn as inspections, sandblasting, hydro jetting and painting, repair work and regular maintenance operations as carried out down in cargo holds or the like. In the following, the invention shall be more closely described with the help of some preferred embodiments. This description is not intended to limit the extent of the invention, which only can be seen m the enclosed claims. One skilled m the art can implement the invention with modifications which are appropriate, for the different conditions at different workplaces, without these modifications taking it beyond the scope of the claims . The invention shall be described m greater detail with reference to the figures following, in which Figures 1 and 2 illustrate a schematic longitudinal elevation and side elevation of an implementation of the invention. Figure 3 illustrates a schematic perspective elevation of a yoke construction. Figures 4, 5, and 6 show an actual implementation of the invention, m which the working platform is adjusted from, for example, a position mounted m parallel to the rail to a working position across the rail after which the stabilising device is activated. The figures 7 and 8 show a side and cross-section elevation, respectively, of an alternative construction for suspension of the yoke construction. Figure 1 shows a form of implementation of the platform system with a suspension rail 10 for fastening to a ceiling construction (tier of beams etc.) 12,14, aoove the workplace. Below, and attached to, this suspension rail 10, the platform 16 itself is hung from a suspension point with the aid of a simple suspension arrangement 18. The suspension arrangement 18 is formed from a housing part 18, the upper section 21 of which includes a set of wheels for mounting to a superjacent rail 10 (or rail pair) m the superjacent ceilmg/beam construction, while the lower section 23 includes devices to rotate the lower section m relation to the upper section, and furthermore a yoke construction is mounted to the lower section 23. In the illustrated embodiment, the suspension arrangement 18 can be rotated in a horizontal plane. Thus, the platform can be rotated horizontally 360° around the suspension point on the rail around an axis 20. The suspension arrangement 18 comprises an m-built motoring drive (preferably operated by remote control by the operator on the working platform) to perform the mentioned rotation. The suspension rail 10 and suspension arrangement 18 can also be slanted when required, but horizontal or approximately horizontal mounting will be most common and preferred. As it can be seen from figure 1, the suspension arrangement 18 comprises a runner 22 for movement along the suspension rail 10. In the illustrated embodiment, the ceiling construction comprises a support beam 24 to which the suspension arrangement 18 is secured. A yoke construction 26 is mounted on, or suspended from, the suspension arrangement 18. The yoke construction 26 comprises, as can be seen as an example m figure 3, a basically rectangular trusswork frame construction of longitudinal and cross-ways frame- or beam parts 28,30, respectively, and a middle central seat 32 where the suspension arrangement 18 for the upper anchoring point for the rail unit 10 is secured. Additionally, the yoke construction can oe formed into many other shapes than the rectangular. Thus, it may be m the form of an I or H shaped beam or similar. On each end of the frame construction (i.e. adjoining each of the 4 corners), the suspension arrangement 34 (wires, cables, etc.) for the working platform 16 is fastened. The suspension arrangements 34 are comprised of preferably steel rope or wires, but may also include strong ropes, rods or similar tensile devices. The suspension arrangements 34 have the task of carrying the floor part 36 of the platform 16 lself as this is secured via a lifting mecnanism 38. As shown m figure 3, the yoke construction includes 4 cables 34, one m each corner, from which the platform is suspended. In an alternative embodiment, the floor part can be secured by a simple mechanism for permanent anchorage at a fixed height . The anchoring mechanism can furthermore be in the form of a pulley or simply as fixed knots or ears. Consequently, a flexible access is secured m the vertical direction by the platform being equipped with the mentioned hoisting mechanism 11 which is arranged with a known method (motor driven) for it to be raised/lowered. In this way a vertical movement m relation to the suspension point on the suspension rail is achieved. The lifting arrangement for raising and lowering of the working platform can possibly be arranged m connection with the working platform itself. According to the invention, to the upside of the yoke construction 26 there is mounted stabilising devices m the form of one or more upward extendable (such as telescopic) rods, 40,42,44,46, as shown m figures 4-6. The rods are arranged to push, with their respective ends, up against the ceiling construction with a given force such that the yoke construction is stabilised m an approximately horizontal position, and is thus prevented from tilting vertically. The pushing rods include preferably piston/cylinder units. With the aid of a hydraulic fluid, the cylinder chamber can, m each unit, be put under pressure such that the piston of the unit s pushed outwards until it abuts a superjacent ceiling construction. The pressure m the fluid is regulated such that a given pushing pressure is obtained and satisfactory stabilisation of the yoke construction is obtained. As shown m the figures, the pushing rods 40,42,44, 46 may, according to an optional solution, be changed between a basically horizontal, collapsed, inactive position, according to figure 5, and a vertical, raised, active position according to figure 6. The figures show only two of the pushing rods 40 and 44. The change between collapsed and raised rod positions can be brought about by two additional piston/cylinder units mounted on the yoke frame itself, with only two being shown by the reference numbers 52 and 54 m the figures 4-6. Furthermore, the lower part of each support rod can be hinged, such that it can be folded m a satisfactory way so that it does not take up too much space on the yoke itself. The extendable pushing rods can Joe of any type that can be driven with the aid of a hydraulically, pneumatically or electrically driven power unit. It is also possible to use inflatable support pads and the like. Furthermore, the end of the rods can comprise wheels 66 which can roll along the superjacent surface, e.g. a plane ceiling surface. In this way, it will be possible, if necessary, to displace the construction without relieving the pushing force from the pushing rods, as the rods can roll along the ceiling surface and maintain the abutment force against the ceiling. The figures 4-6 illustrate, according to an alternative, how the arrangement, according to the invention, is utilised. These figures show the rail 10 which is secured to a superjacent (not snown) tier of ceiling beams, the yoke construction 26 which is suspended from the rail 10 through the suspension arrangement 18 and the platform 16 suspended downwards from the yoke construction 26. The person, who will work from the worKing platform, is not shown. Figure 4 shows the constructions wnere the yoke construction 26 and the platform 16 are positioned parallel to the rail 10 m the ceiling. The support rods 40-46 are collapsed m their inactive position with aid of the devices 52,54,56,58. The drive unit m the suspension arrangement 18 is activated and the whole of the construction is rotated ca. 90° around a horizontal plane such that it takes up the position snown m figure Ξ, said position corresponding to the actual position for the working operation which will be carried out by an operator. As indicated in figure 6, the devices 52,54,56,58 are now activated by pressurising their cylinder chambers such that the supporting rods 40-46 are raised to an approximately vertical position. Thereafter, the cylinder chambers of the rods are put under pressure such that the rods are pushed outwards and upwards until they abut the superjacent ceiling. As each extension occurs independently, the rods can be pushed towards part of the ceiling at different heignts. The pressure m the fluid in each individual unit 40-46 is regulated such that a given pushing pressure is obtained and a satisfactory stabilisation of the yoke construction is obtained. Now, one person can stand at one end of the platform 16 without the suspension arrangement 18 (which is the only anchoring point to the rail 10) being exposed to damaging momentum loads . As can be seen m figures 1 and 2, tne floor part 36 of the platform can be equipped with 4 runners 48 which are used for movement in connection with transport, and for movement of the floor part 36 during assembly or disassembly. Furthermore, the floor part s equipped with railings 50. The assembly of the platform system is simple and it will ta e two fitters around 4 hours to do it. In a tank on ooard a ship, the assembly starts at the bottom of the tank, with the platform parts floor 36 and railing 50, and the equipment with cables 34 and lifting mechanisms 38, including yoke construction 26 with crossbeams 30, being put together. The suspension rail 10 is hoisted up under the deck of the ship and fastened through a threaded rod 60 which is fed through a manhole 62 or similar and secured by the use of a wing nut 64. The threaded rod 60 is secured to the lower edge of the suspension rail 10 by a known method. The supporting beam/yoke construction 26 is, m advance, secured together with the suspension arrangement 18 whicn in its upper edge comprises a crossbolt 19 which runs through two ears, which are spaced apart, and m the upper edge of the lower part of the suspension arrangement. From the outer edge of the crossbolt 19, two carrier-arms stand perpendicular to the crossbolt and on their outer edges each supports a runner 22. Beyond the embodiment which is shown here, the suspension arrangement 18 can be equipped with an associated motorised drive unit which, with a known method, is arranged for motorised movement along the suspension rail 10. During assembly tne platform is lifted up to the suspension rail 10 where the runners 22 are inserted into the side members of the rail 10. For more extensive work along a larger part of a tank wall or the like, it is possible from the floor part 36 of the platform 16 to fit further lengths of the suspension rails 10 as an extension of the first fitted rail and up under the deck. An alternative anchoring arrangement not shown for the suspension rail 4 can be m the form of a set of fastening brackets with through going bolt or the like, where the uppermost brackets are placed m advance, or, as they are needed, are welded or bolted down underneath the deck. Another alternative anchoring arrangement (not shown) for the suspension rail can be m the form of a hoop with a hole m either end, wnicn hangs m an existing ring, hook or the like, and which, via a through going pm or bolt with clamps fastened onto it for this purpose, anchors the suspension rail m position. The yoke construction is arranged to be raised and lowered m relation to the superjacent support construction. According to an alternative solution, the yoke construction can be raised and lowered m relation to a given suspension point m the superjacent support construction. In this way, the stabilising devices 40,46 (see figures 7 and 8) can, m their raised position, by the mentioned controlled raising action, with a given force be brought up against the superjacent support construction. According to this solution, which is shown m the figures 7 and 8, the yoke construction can include its own drive unit/engine unit 70 and cable 72 by means of which the yoke 26 suspended from the cable 72 can be hoisted up towards the ceiling construction 12,14 to its working position, and thereafter, the engine can by remote control be driven by the operator to secure or loosen the yoke 26. As the cable 72 is suspended from the ceiling construction through a rotatmg/swivellmg construction (not shown specifically) , the horizontal rotation itself can be carried out manually by the operator, also because the yoke construction, including the platform, can be a lightweight construction with a total weight, for example, of 500 kg. The supporting devices 40,44,46 include special upward- facing supporting feet whicn can be folded or taken down from a vertical to a horizontal position relative to the yoke construction. The different height positions of the yoke with its supporting feet 40,46 are illustrated in figure 7 at two different height levels A and B. By using this elevation mechanism to clamp the yoke 26 against the ceiling or beam construction, the supporting feet do not need to have any mechanism that clamps them outwards and upwards, as explained earlier. Instead, the lifting mechanism of the yoke is used for the mentioned clamping. But even with this suspension, the supporting feet themselves may be extendable for clamping, as mentioned in the beginning. If the whole of the construction is to be moved, this can easily come about by it being lowered down to the floor, and new cables being secured to another anchoring point m the ceilmg/beam tier, said anchoring point being displaced m relation to the former. With this solution, illustrated m the figures 7 and 8, the construction can be operated without the use of rails m the ceiling. As shown m the figures 1-6, the arrangement can, according to a preferred embodiment, be supplied with an extension of the floor part of the platform, stretching beyond the hanging or suspension devices 34 to secure access to tank surfaces or the like, which may be a distance (indicated as 4-7 m in the shown embodiment) from the suspension point. This give greater flexibility and possibilities to work along surfaces which are a corresponding distance from the closest point of the suspension rail. As the suspension rail 10 can also stretch some beyond the anchoring point in the deck, it is difficult to visualise working situations where the working surface cannot be reached with this platform system according to the invention. For safety reasons the suspension rail should be equipped with a stop mechanism m both ends. Furthermore, optional motorised equipment, for use m tasks with fire- hazards such as in oil tanks, should be spark proof and fireproof otherwise. Even if the description given above is adapted mainly for work inside a snip's tank, a person skilled m the art will easily see that the same system can be used m a number of other work situations, such as in large tanks ashore, under platform decks on rigs (drilling and production rigs) at sea, within carrying columns or legs for oilπαs etc.

Claims: Patent claims 1. Arrangement of a working platform which is suspended from a superjacent support construction, such as a ceiling construction, tier of beams or the like, m that the working platform is connected to the support construction by being mounted m a yoke construction, and m that the platform is arranged so that it can be raised and lowered m relation to the yoke construction, characterised in that the yoke construction comprises a stabilising device, which, with a given force, can be brought to abut the superjacent support construction. 2. Arrangement m accordance with claim 1, characterised m that the stabilising device comprises one or more extendable support devices, such as telescopic extendable rods, m that said stabilisation preferably results in an approximate horizontal position of the yoke construc ion/platform. 3. Arrangement in accordance with any of the claims 1-2, characterised m that the upper part of every support device includes a support foot, or one or more wheels which can roll m abutment along the support construction, or that the upper part of the supporting device can glide along the superjacent support construction. 4. Arrangement m accordance with any of the preceding claims, characterised m that the removable clamping of the supporting device (devices) m abutment with the superjacent support construction is carried out by a nydraulically, pneumatically or electrically driven power 5. Arrangement m accordance with any of the preceding claims, characterised m that the suspension arrangement (18) comprises a housing part with an upper section (21) and a lower section (23), said sections can be rotated individually around a oasically vertical axis (20) , in that the housing part (18) comprises means to rotate the lower section (23) m relation to the upper section (21) , m that the upper section (21) comprises a pair of wheels (22) for mounting on to a rail (or pair of rails) (10) m a superjacent ceilmg/beam construction, and in that a yoke construction (26) is anchored to the lower section. 6. Arrangement m accordance with any of the preceding claims, characterised m that the yoke construction is arranged to rotate m a horizontal plane m relation to the superjacent support construction. 7. Arrangement m accordance with any of the preceding claims, characterised m that the yoke construction is mounted horizontally rotatable in an anchoring device, said anchoring device being arranged to be displaced horizontally along a rail which is mounted in the anchoring base . 8. Arrangement m accordance with any of the preceding claims, characterised m that the mid-point of the yoke construction is secured to the anchoring device. 9. Arrangement in accordance with any of the preceding claims, characterised m that the yoke construction comprises a longitudinal support rail or frame construction, with each end of the rail/frame comprising said number of support devices. 10.Arrangement m accordance with any of the preceding claims, characterised m that the working platform is suspended from the yoke construction via a number of cables, wires, or rods or similar tensile devices, and the means for raising and lowering of the working platform is arranged m connection with the yoke construction and/or m the working platform. 11.Arrangement m accordance with claim 1, characterised in that the yoke construction is arranged to be raised and lowered m relation to the superjacent support construction. 12.Arrangement m accordance with claims 1 and 11, characterised in that the mentioned stabilising device, which with a given force can be brought to abut the superjacent support construction, is comprised of a number of the upward- facing support devices m the yoke construction, which with a controlled raising of the yoke construction are brought to abut with the superjacent support construction with said force. 13.Arrangement m accordance with claim 12, characterised m that the support devices comprise support feet which can be folded or taken down from a vertical position to a horizontal position relative to the yoke construction.

Inventors: AALAND OVE, AALAND, OVE
Applicants: AALAND OVE, OBO UTSTYR AS, AALAND, OVE
Application year: 1999
Main classification: E04G3
IPC codes: B66F11, E04G3