SE1500266A2 - Device in lifting a Car/Truck carrying deck panel aboard a multi deck Pure Car/Truck Carrier (PCTC) - Google Patents

Abstract

Device to from below lower/lift a deck panel for carrying cars/trucks aboard a multi deck carrier (PCTC) in the form of a thereunder placed drivable truck (1), whereby said truck comprises a raisable lifting/lowering device (4), having at its top a lifting frame (5), which lifting frame (5) has support arms (9) attached horizontally pivotally, to be controlled from its rest position at the truck to its lifting position by at least one controlled linkage (16), making It possible to steer out the arms (9) to spread lifting pattern giving the most fortunate lifting points for a specific deck panel (11), and that the support arms (9) comprise extensions (10), at the ends of which jacks are arranged, and a method for using the device to apply the lifting means (9, 10, 15) at a number of choice specifically calculated for each cargo hold (13) that (11) is to be lifted/lowered.

Description

Image available on "Original document" Method and device in Lifting a Car/Truck carrying deck panel aboard a multi deck Pure Car/Truck Carrier (PCTC) Technical field The present invention relates to a method and a device in intercontinental car and truck carrier ships, carrying cars and trucks of different sizes from its manufacturers with almost no exception from long abroad across at least one large ocean. More specifically the method relates to the use of lifting means applied under deck panels arranged inside holds of such ships, being reversibly rateable and/or extendable and/or liftable and/or lowerable to lift or lower said deck panel to different lockable height positions for allowing loads of different sizes to be loaded.

To make this possible in an economic way, these earner ships are carefully optimized and has consequently become very large and are nowadays mainly limited in size by the routes they travel at sea, for instance through the channel of Panama. Actually and fa. the broadening of this channel has brought as a consequence a demand for even wider ships for this kind of trade. Deck panels aboard such ships, dividing holds of different decks into adaptable compartments, are either hoistable or liftable, where the latter principle in comparison due to two factors is most frequently used, namely fee fact feat this principle is less costly when it comes to hardware while it has at least as good operational flexibility as the more expensive alternative, thus the principle with liftable panels is preferred. Normally when today such a carrier ship is loaded and unloaded the cars and/or trucks are driven into and out of the cargo hold of these big carriers, while they therein are being separated by up to thirteen separate deck levels of which up to five may be Irftable/lowerable and which can be arranged at different heights according to the actual need.

Technical pr Image available on "Original document" em All the lowerable/liftable deck panels of each deck and hold are stowed at the uppermost part of each cargo hold of the ship and are lowerable and liftable by more or less standardized decklifting equipment, such as a mobile scissors lifter or other equal device for lifting/lowering. When a transport with a ship of this kind is to be made, planning is very important The ship in question has a given capacity, which may be optimized through careful planning regarding how to arrange the liftable/lowerable panels to achieve the best possible weight distribution as well as the best possible use of the ship's capacity overall.

The movable panels are arranged at suitable heights needed for toe kind of vehicles to be transported before and during loading of the ship's deck holds is made. The ship is thereafter compacted at a number of locations simultaneously, using ramps as interconnecting means between different levels thereof. During the operation of arranging the lowerable and liftable deck panels property, each panel is securely fixed at its required specific height either to the hull of the ship, to support pillars arranged between floor and roof in the cargo holds or for instance to suspension stays. The fixation is made by fixation means located at a number of points along the peripheral edge of each panel and at said pillars. Such a lowerable/liftable deck panel is for quite obvious reasons fairly heavy in order to be able to carry its load of cars or trucks. Due to its own weight, however, a certain downwards deflection at the center of each panel (called sagging) was historically experienced especially when not loaded and would still be experienced if not counter measures had been taken. Therefore each panel is nowadays by its construction pre-stressed to have a greater capabity to when not loaded carry its own weight without such sagging at its middle region. When loaded, however, it is a completely different question, downwards deflection Is then unavoidable and actually a matter of dimensioning of the structure to optimize load and minimize loaded deflection. The object of the mentioned pre-stress or pretension, however, is to obtain inasmuch as this is possible a completely undeflected deck panel when the same is to either a stowed supported condition or to a supported condition for loading, Ie. when supported along its edges and if above a certain size due to strength aspects by the use of support stays, supporting the deck panel also therebetween. Since each of the panels, when the principle of liftable/lowerabie deck panels is used, is lifted by a mobile centrally applied lifting device that consequently applies a force greater than that from the weight of the whole panel itself at a fairly small central area of the panel, the lifting gives due to said pre-tension as a consequence an even greater edge deflection downwards (more or less the double) and the middle of these panels will have an upwards deflection above the lifting device (edges down, mid-region up), which unlike the desired sum of deflections, is as close as possible equal to zero, when the panel is supported, however, not loaded. This is, however, most unwanted due to the tact that all these deck panels are stowed at the top of their respective cargo holds when not used. This position will with margins and tolerances be the uppermost position of each lifttable/lowerable panel. So when the panel then is lowered to its stored position onto or locked to the structure or supports, a waste (void) volume is created, between the liftable deck panel and the deck above. An occasional annoying effect of this phenomenon is that when a deck panel is fited to its presumed storage position, the deflection thereof becomes so great that its mid-portion hits the interior roof or the preceding deck above, before the deflected lifted deck has reached a position required for the same to, as it should be, without such deflection be able to become locked to la. the hull and the pillars with its above mentioned fixation means. To be able to minimize these effects, sometimes shim plates are used to during lifting and lowering of the same keep the deck panels as parallel to the lifting plane as possible, however, the deflection issue still remains. This means that each panel in its stowed position must be positioned lower than else, which consequently instead leads to higher ships, if the same number of liftable/lowerable deck panels are to be (stalled In a ship of this kind. As ships recently projected are essentially larger, the top deck of such a ship due to the necessary clear height becomes much higher than else, in order to be able to contain all decks and their required individual waste (void) volume, when unloaded. As the ship as a whole becomes higher, the unwanted effects that both the ship's height over water dimension becomes greater and the ship's center of gravity becomes with regard to the ship's stability negatively affected. This means that a larger amount of ballast has to be used, which in turn leads to a higher displacement and larger fuel consumption. The latter effects are most unwanted both för environmental and economic reasons.

As if this was not enough, the problem with larger waste or void volume as such, will in the future also become even greater, as ships of this kind, as mentioned above, most likely will become much wider. The effect of both wider and higher, the latter as a consequence of the deflection phenomenon of the deck panels, a top of this leads to a larger wind resistance, the environmental effect of which will be extensive due to a most likely significantly higher fuel consumption and will of course mean an increase of the transportation costs as a whole, which most likely also will lead to higher CO2-emissions, which is totally unacceptable.

State of the Art A lowerable/liftable car or truck carrying deck panel aboard such a carrier is normally fitted by a drivable truck, having as its only object to lift and lower the decks of such a carrier. Such a drivable truck is normally very sturdy and carries extendable outriggers to apply against the floor or deck on which it stands. At the very top of such a truck, a scissors lift or other push-up device for heavy loads is arranged. The sites where the truck in question is to be placed for its lifting operations is marked on the deck and the truck is manually controlled to get into the correct position for lifting. Each ship has its very own lifting truck/-s, which travels along with the ship on its journeys and are consequently always available. Previously known such trucks, however, apply its lifting, or supporting force, at a central balance spot area on the below side of each panel and therefore gives rise to the negative effects and problems of unwanted deflection related above. Also at times when a ship does not lie completely in wave, problems arise due to deck panels being jammed due to displacements between these and the hull.

Object of the invention A main object of the present invention therefore lies in keeping a liftable/lowerable panel of this kind as adaptive and undeflected as is ever possible during lifting/lowering of the same, in order to be able to apply support means arranged to the hull of the ship or to pillars inside the latter dose to (slightly above) its normal points (stowed deck panel position) of engagement without difficulties as well as avoiding all unnecessary waste (void) volume in the areas where such panels are to be stored when not in use.

According to the invention said lifting means are applied at a number of choice specifically calculated for each cargo hold dependent upon which carrying panel is to be lifted/lowered, while said lifting means is/are controlled from rest position/-s in applying a distributed lifting force pattern below said deck panel, for lifting or lowering the same in applying lifting force/-s in an individually controllable pattern thereon, so that the deck panel when in an unloaded state will be lowered and lifted undeflectedly, or deflected, in an as far as possible, predictable fashion.

The lifting means may be installed in for instance a drivable truck, whereby said truck may comprise memory functions allowing the truck to recognize a specific liftable/lowerable deck panel. Said recognition may be performed making use of environmental RFID (Radio Frequency Identification) or for instance a photographic scanning technology. Since each panel is individual, its identification gives the lifting means information regarding how and where to apply the lifting means in an optimal fashion. Above all the lifting means may comprise adjustably and remotely controlled lifting elements, making it possible to make these either self adjustable, dependant on a predefined load/stroke of said lifting element, with regard to when the force of the lifting element reaches its predefined top value or with the ability to compensate for a deflection of the lifting means itself or for unisotropical properties in specific panels to be handled.

By arranging individual jacks below said deck panel either mounted as a fixed installation in the ship or put there with the use of conventional cargo handling equipment, such as a forklift, a very uncomplicated yet very reliable way of relocating the deck panels can be achieved. Also with this lifting/lowering principle a highly automated localization is applicable with regard to individual jacks.

Said lifting means may comprise support arms that are arranged at sides of a drivable truck and which are able to in a controllable fashion be pivotally swung to a position representing diverging lifting points/areas for applying said lifting force to internal positions representing a most favorable spread lifting force application. The lifting positions are based on stability calculations for each deck panel to be lifted/lowered, since there are many different individual panel shapes, sizes, weights and structures. Using such a method would certainly be much cost effective when it comes to keep the deck panels to be lifted/lowered undeflected or deflected in a predictable fashion. In a further developed version of the method, said support arms are extendably designed to make them easy to stow while making it possible for them to apply its lifting force as for out below a deck panel as is possible/necessary. This development shows how a small, at first sight insignificant detail can have the greatest importance. In yet a further developed version of the method according to the invention said lifting elements (mentioned above) at their outermost ends of each support arm, can for instance by hydraulic means be extended in the lifting direction by pushing up the panel in its contact point at least 300 mm, however not limited thereto. This featured method of correcting the applied lifting force/stroke to a different from both the panel of the deck panel as well as the maybe out of wave ship as a whole and/or to compensate for a deflection in arms, frames, and/or chassis or the deck below, gives an opportunity both to correct deck panels having one or more comerAs deflected low or a whole deck panel that for whatever reason has got stuck and needs an extra push-up, and to give a refractory deck panel a necessary extra lift, if needed to get it locked in correct position.

In another yet further developed embodiment erf the invention said lifting elements are made from or coated with a material with a friction coefficient higher than steel against steel (not limited thereto). The aim with this is of course to reduce the risk of slipping when a lifting/lowering operation is made in a skewed fashion. The below side of each deck panel are in the area where the lifting means are to be applied provided with reinforcements in the form of for instance reinforcement plates sized 1x1m welded thereto.

Description of the drawings The invention will in the following be described with reference to drawings of a presently preferred embodiment of the invention, in which: Fig 1 shows a schematical perspective view of a drivab!e truck suitable but not necessary for the implementation of the invention, Fig 2 shows a schematic isometric view of a cargo hold which for illustrative purposes comprise one liftable/lowerable panel only as well as a drivable truck, Fig 3a and b shows side views of a cargo hold according to that shown in Fig 2, in which the results both of prior art and new methods of translating panels are shown, Fig 4 shows the same schematic cargo hold as above with a drivable truck in a position for initiating a lowering of a carrying panel, Fig 5 shows the same cargo hold as in fig 4, with said drivable truck shown in two of its extreme positions, Figs 6 shows a view from above of the drivable truck with lifting means extended and Fig 7 shows as an isometric view said drivable truck released from all surroundings, holding a carrying panel in an uplifted position.

Detailed description According to Fig 1 a drivable truck 1 is shown for lowering/lifting deck panels 11 (not shown in fig 1) aboard a Pure Car/Truck Carrier (PCTC, (not shown)), comprising as its main components a chassis 2, four thereto fixed hydraulically (in this embodiment) maneuvered support stands 3, a hydraulically maneuvered (in this embodiment) scissors lift 4, a lifting frame 5 and an open yet protected drivers cabin 6. The drivable truck 1 further comprise four steerable wheels 7 for facilitating its handling and positioning on the deck 8 (not shown extracted in fig 1) of the PCTC. At its respective comers, the truck 1 comprise controllably and pivotally arranged support beam arms 5 9, in the interior of which suitably hydraulically maneuvered (in this embodiment) extensions 10 (not shown in fig 1) are situated, making it possible to further extend each arm 9 according to the actual need. The degree to which pivotation is made as well as the extent to which each extension 10 is extended is controlled either manually or automatically based on information given the truck when in place below a 10 specific plane of a hold. A person skilled in the art, however, immediately realizes that a truck of this kind is not necessary. Instead any other lifting device/-s that is/are able to apply a lifting force accordingly, would equally good solve the problem of deck panels deflecting in the described unfortunate fashion.

According to fig 2 a view schematically illustrates a suitable position of said drivable 15 truck 1 for lifting, supporting and lowering a car/truck deck panel 11. For illustrative purposes this view shows only one liftable/lowerable deck pane) 11.

A PCTC may normally, however, comprise up to three such deck panels in each cargo hold, where a cargo hold is the volume created between two fixed decks. This view also shows locking or fixation means 12, here situated at pillars supporting both 20 the fixed deck above and each deck panel 11.

To more clearly elucidate the problem solved by the invention, Fig 3a and 3b respectively shows on the one hand a lifting operation according to prior art and on the second hand a lifting operation performed using the method end device according to the invention. As is shown in fig 3a, lifting/lowering a panel 11 making use of a 25 centrally thereunder applied lifting appliance will give rise to a deflection ? of said deck panel 11 , this for obvious reasons being the largest at the outermost portions of the deck panel 11. This deflection ? necessitates an “overlifting" of the panel 11 for its locking or fixation means 12 to work, however, this ‘overlifting requires a waste (void) volume above the panel 11 if the panel is not to hit the inner side of the ceiling 30 above it before the fixation means can be established. It is this waste volume that when multiplied maybe five times that gives as a result an unnecessary high ship over water or an increase of the ship's centre of gravity (COG) and lowers its stability, something that requires to be compensated with fixed ballast or such comparted in tanks. Instead according to the Invention the fitting of said panel 11 is, as is shown in fig 3b, performed in a simply expressed “widespread" fashion by for instance making use of a recently developed lifting frame 5 of a scissors lift 4 of a drivable truck 1. By applying the lifting and supporting force at three or more paints spread towards the edges of the panel 11 , the deflection can mainly be avoided to such extent that it is no longer a problem and the deck panel 11 will, as is shown In fig 3b, keep its undeflected and parallel state to support panels or deck panels shape, even if lifted/lowered, reducing the effects of fitting device deflections, uneven supports in the deck below and the structural deck shape of the ship, that Is dependant on load and temperature. Thereby all difficulties in the context are resolved in a simple and elegant fashion. Both the need for unnecessary waste (void) volume and the specific items regarding getting locking means 12 to correctly and safely interact with its counterparts of the panel at la. the outer boundaries of the carrying panel 11 are eliminated.

In order to further elucidate the performance of the method and device according to the invention, this will more in detail be described hereinafter. In Fig 4 is shown a hold 13 of a much greater cargo space of a PCTC. In order to keep it simple and not to add any unnecessary details only one deck panel 11 is shown. The cargo holds in total of a PCTC may in total contain up to five liftab!e car deck levels divided into separate deck panels, whereby in a simple calculation the resulting waste (void) volume without the invention becomes multiplied with the number of deck panels (11). The drivable truck 1 is in Fig 4 shown from its front having its support beam arms 9 and extensions 10 extended to a position ready for lifting/lowering the deck panel 11 to its momentary use position. This is even more clearly shown in Fig 5. in which the lifting frame with its newly developed pivotal and extendable arms 9,10 are shown both in its lowermost position and in its uppermost position (dotted lines). The deck panel 11 can here easily be brought to interact with either locking means 12 on its way up or down, while handled by the drivable truck 1.

As pointed out before, the described solution is not the only possible one, however, a feasible and very efficient one. Lifting of such deck panels 11 can be performed either by solitary lifting units put in place by for instance conventional forklifts, or for instance by a truck like the one shown, however, carrying lifting elements of a different design, such as suitably designad jacks brought to a correct position by means arranged to a truck of the same or similar type.

Fig 6 even more clearly shows the drivable truck 1 from above with its support beam arms 9, with its extensions 10 fully extended. It cannot be stated more clearly, quite obviously these arms can be differently designed in detail. It is of course possible to arrange more arms to the lifting frame if considered suitable. In other words the arms can be differently outlined, stored and dimensioned, however, without escaping from the main inventive concept, stated in the appended claims, Finally, shown in Fig 7, the solution and inventive concept of the invention is clearly and in a very illustrative view shown from below a deck panel 11, being lifted with a drivable truck 1. The truck has its support stands 3 grounded, it's scissors lift 4 extended dose toils maximum extension, and it’s support beam arms 9 and it’s extensions 10 pivoted and extended respectively. A lifting/lowering supporting force is applied to the below side of the deck panel 11 at chosen suitable sturdy or enhanced points of attack in the vicinity or close to the edges of the deck panel 11 as is shown in order to fully make use of the effects of the invention. At each of the outermost ends of the extensions 10, lifting elements 15 are arranged. Each of these may for obvious reasons be made from or treated with a material having a high constant of friction in order to minimize the risk that one of these elements should slide while it performs its lifting/lowering operations. In order to allow for a slight out of wave status of the ship and yet allowing the truck to perform its job, the lifting elements are each preferably hydraulically extendably mounted to the extensions, making it possible to apply a plane of attack that can vary from completely in wave to a selfdeflection as previously mentioned, hereby minimizing the risk for the deck panels 11 to get stuck inside a hold 13 and making it possible to, due to unforeseen reasons, adjust the position of a deck panel when to be stored, if the fixation means in spite of this new lifting method and its hardware fails to cooperate in the correct fashion. If a deck panel 11 is not lifted in parallel to its support plane, it might without these extendable lifting elements 15 not reach toe supports thereof in stowed position.

In order to once and for all clearly elucidate the method and device of the invention hereby a description in terms of use is given. Given all possible embodiments of the invention, this specific description prescribes the use of a drviable truck 1 as a with the ship co-travelling element When a liftable/lowerable deck panel 11, for instance before loading of such a ship, is to be taken into use, such a drivable truck 1 is driven in below the stored position of such a deck panel 11. The truck 1 is positioned at a predetermined position on the lowest fixed deck panel of a specific cargo hold 13 of such a ship, representing a spot where the deck panel 11 in question may be lifted/lowered in balance. The lifting frame S of said truck 1 is lifted while lifting elements 15 on lifting means thereof are being controlled to establish themselves at positions representing a lifting pattern, that is specific for each liftable deck panel 11 aboard the ship. When so established, the lifting elements 15 are brought into contact with the below side of the deck panel 11 to be lifted/lowered. If now due to for instance unisotropic properties of the specific panel to be lifted/lowered, all positions on said below side are not situated at the exact same height the lifting elements 15 are controlled to such an extent that a oommon lifting at all points can be made at the same time. The panel 11 is thereafter slightly lifted to make it possible to free the locking means 12 in the storage position, whereafter the panel is lowered to a position matching a position required for transporting for instance trucks of a specific size. Other locking means are here activated and the deck panel 11 1n question is thereafter ready to be loaded by the use of for instance ramps interconnecting different levels on the ship or levels from the quay to a specific level on the outside of the ship where the panel 11 is situated. The measures to be made when a deck panel 11 instead is to be stored are more or less the same, though in a different order. Should during lifting a specific panel 11 to its storage position, due to therein inherent unisotrophy one or more corners or lengths of the panel 11 for some reason be deformed, the lifting elements 15 are dimensioned to be able to in spite of such a deformity be able to give any such panel 11 an extra push-up where required, to be able to secure the panel to its locking means 12 in a completely secure fashion.

Additionally, variations to the disclosed embodiment can be understood and effected by the skilled addressee In practicing the claimed invention, from a study of the drawings, the disclosure, and tie appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a” or "an" does not exclude plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. 1. Drivable truck 2. Chassis 3. Support stands 4. Scissors lift . Lifting frame 6. Drivers cabin 7. Steerable wheels 8. Deck of PCTC 9. Support beam arms . Extensions 11. Car/truck carrying panel 12. Locking means 13. Hold 14. Great cargo space of PCTC . Lifting elements 16. Linkage(controlled) 17. Hydraulic cylinder unit (for Lifting elements 15)

Claims (15)

1. Method in lowering/lifting a deck panel (11) carrying cars/trucks inside a hold aboard a multi deck carrier (PCTC), while using at least one lifting device (1) having lifting means applied under said deck panel (11) being reversibly raisable and/or extendable and/or liftable and/or lowerable to lift or lower said deck panel (11), characterized in that said lifting means (9, 10, 15) are applied at a number of choice specifically calculated for each cargo hold (13) dependent upon which carrying panel (11) is to be lifted/lowered, and that said lifting means (9, 10, 15) is/are to be controlled from rest position/-s in applying a distributed lifting force pattern below said deck panel (11), för lifting or lowering the same by applying lifting force/-s in an individually controllable pattern thereon, so that the deck panel (11) when in an unloaded state can be lowered and lifted either undeflectedly or deflected in an as far as possible predictable parallel fashion.

2. Method according to claim 1, characterized in that individual jacks are placed below said carrying panel either mounted as a fixed installation or put there with the use of conventional cargo handling equipment, such as a forklift.

3. Method according to claim 1 characterized in that said lifting means comprise support arms (9) arranged at sides of a drivable truck (1) and able to in a controllable fashion be pivotally swung to a position representing diverging lifting points/areas for applying said lifting force to internal positions representing a most favorable spread fitting force application based on a stability calculation for each deck panel to be lifted/lowered, to keep the deck panel (11) undeflected or deflected in a predictable fashion.

4. Method according to claim 3, characterized in that said support arms (9) are extendably designed to make it easy to stow while making it possible for it to apply its lifting force as for out below a deck panel (11) as is possible/necessary.

5. Method according to claim 4, characterized in that lifting elements at the outermost ends of each support arm are extendable in the lifting direction to compensate for all possible deflections.

6. Device to from below lower/lift a deck panel for carrying cars/trucks aboard a multi deck carrier (PCTC) in the form of a centrally thereunder placed drivable truck (1), characterized in that said truck comprise controllable arms (9) and/or extensions (10) at the ends of which jacks are arranged, which when in an active position, at from the position of said truck diverged positions can perform a complete liftng/lowering operation in tune.

7. Device according to claim 6, characterized in that it comprise a raisable lifting/lowering device (4), having at its top surface a lifting frame (5), and in that the lifting frame (5) at its periphery has at least three support arms (9) attached horizontally pivotally, to be controlled from its rest position at the truck to its lifting position, by at least one controlled linkage (16), making it possible to pivotally steer out the arms (9) to positions representing a spread lifting pattern giving the most fortunate lifting points for a specific deck panel (11).

8. Device according to claim 6 or 7, characterized in that the truck (1) comprise at least four steerable wheels (7) making it easily maneuverable.

9. Device according to claim 7, characterized in that the support arms (9, 10) are extendable to a length almost doubling the length thereof and that the support arms at their outer ends comprise fitting elements (15) for compensation of the lifting/lowering position of each arm.

10. Device according to claim 7, characterized in that either one of or two or all of the controlled linkages (16) the extendable arms (9,10) and the lifting elements (15) are hydraulically or electrically maneuverable.

11. Device according to claim 9, characterized in that each said lining element is mounted atop of a lifting unit (17), making it possible to at range individually control the lifting position of the lifting point of each arm (9. 10).

12. Device according to claim 11, characterized in that the stroke of said lifting unit lies in the range of up to at least 200 mm.

13. Device according to anyone of the preceding claims, characterized in that said truck (1 ) comprise memory functions allowing the truck to recognize a specific liftable/lowerable deck panel (11).

14. Device according to claim 13, characterized in that in identifying, recognizing and instructing the device of a specific deck panel it comprise environmental RFID (Radio Frequency Identification) and/or photographic scanning technology.

15. Device according to claim 14, characterized in that the force/stroke of said lifting elements are either self adjustable, dependant on a predefined load of said lifting element or is restricted with regard to when the force/stroke of each lifting element reaches its top value.