Patent Publication Number: US-2017369291-A1

Title: A lifting apparatus and system for shipping containers

Description:
The present invention relates to a lifting apparatus and system for lifting intermodal or shipping containers and relates particularly, but not exclusively, to a system for lifting shipping containers a short distance above the ground so as to be able to connect wheels to the shipping container to allow it to be moved a short distance. 
     Shipping containers are used extensively around the world for shipping goods but also for storage on factory sites. An empty 20 ft shipping container (dimensions 6 m×2.4 m×2.6 m) typically weighs 2.2 tonnes and can be filled to a gross weight of just over 30 tonnes. As a result, specialist equipment is required to manoeuvre a shipping container even a short distance and this is typically in the form of a specialist crane or forklift like vehicle. Such cranes and vehicles are expensive to hire making the process of moving a shipping container a short distance expensive. 
     Systems have been developed to assist in the lifting of shipping containers which attach to the top and bottom cast corner blocks of the shipping container allowing the system to be fixed to the container so that it can then be lifted using a hydraulic ram. However, such systems are heavy to use and difficult to securely fix to the corner blocks, particularly those at the top of the container (at the height of 2.6 m) therefore requiring two or more people to attach the systems to the containers. 
     Preferred embodiments of the present invention seek to overcome the above described disadvantages of the prior art. 
     According to an aspect of the present invention there is provided a lifting apparatus for use in a lifting system for lifting a cuboid shipping container, the apparatus comprising:— 
     at least one lifting device having a first portion with a ground surface engaging member and a second portion movable relative to said first portion;
 
at least one container corner aperture engaging member for engaging an aperture in a base corner block of a cuboid shipping container, said aperture engaging member connected to said second portion and in use bearing the weight of the container; and
 
at least one container frame engaging member connected to said second portion for engaging a portion of a frame of the container above the container base corner block and below an upper corner block vertically opposed to the base corner block.
 
     By providing an apparatus with a container corner aperture engaging member and a container frame engaging member the advantage is provided that the position of the lifting device relative to the weight bearing corner aperture engaging member causes the frame engaging member to be pressed into engagement with the frame of the container. This results in a very secure connection between the lifting apparatus and the container and as a result, a compact lifting apparatus can be provided which is able to stably lift a corner of a shipping container. Because the lifting device must be located a short distance away from the base corner block of the container, the lifting force is being applied a short distance away from the part of the apparatus that is carrying the weight (the aperture engaging member) causing a turning moment to be applied to the apparatus about the aperture engaging member which in turn causes the frame engaging member to be pressed into engagement with the frame of the container. The greater the weight that is being lifted the greater the force that is applied by the frame engaging member. As a result, the apparatus, when used in conjunction with three similar apparatus, can be easily and safely handled by one operator working on the ground and at the base of the container to lift the container so that wheels can be attached to or positioned under the container. The operator does not require the specialist training needed to safely operate the specialist cranes and forklift like vehicles currently used to move shipping containers. 
     The apparatus may further comprise at least one body connected to said second portion, said container corner aperture engaging and said member container frame engaging member. 
     By providing a body to which the lifting device, container corner aperture engaging member and frame engaging member are all attached provides the advantage that a standard hydraulic cylinder can be used as the lifting device which is fixed to the body and the corner aperture engaging member and frame engaging member can also be easily attached. 
     Furthermore, the fixing of the hydraulic cylinder can be such that standard fixings on the hydraulic cylinder (for example an external thread around the end of the cylinder barrel) can be easily used to secure the cylinder to the body. 
     In a preferred embodiment the lifting device comprises at least one hydraulic cylinder. 
     In another preferred embodiment the first portion comprises a piston of said hydraulic cylinder and said second portion comprises a cylinder barrel of said hydraulic cylinder. 
     The container corner aperture engaging member may comprise a rod portion connected to said second portion and a locking flange at a distal end of said rod portion, said container corner aperture engaging member being rotatable relative to said second portion between an unlocked condition in which said flange is able to move into and out of the container corner block aperture and a locked condition in which said flanged is unable to move into or out of the container corner block aperture. 
     This aperture engaging member utilises a standard form of attachment for securely locking onto a shipping container. Furthermore, once engaged with the corner block aperture and carrying the weight of the container, it is impossible to detach the aperture engaging member from the corner block. 
     The apparatus may further comprise at least one sliding handle having a lever connected thereto for causing the rotation of said container corner aperture engaging member between said locked and unlocked conditions. 
     The apparatus may also further comprise at least one locking member for preventing movement of said sliding handle when said container corner aperture engaging member is in said locked condition. 
     In a preferred embodiment the container frame engaging member comprises a frame contact member and a positioning member for moving the frame contact member relative to said second portion of said lifting device. 
     Having a movable frame engaging member has the advantage that the frame engaging member can always be moved into engagement with the frame of the container irrespective of slight variations in the formation of the container or in situations where slight damage has occurred to the container. In order to ensure that the stresses on the lifting apparatus, in particular around the junction between components such as the body and the hydraulic lifting cylinder, are minimised it is important that the cylinder is lifting vertically upwards. As a result, the frame engaging member can be moved into engagement with the frame so as to prevent the apparatus from leaning inwards towards the frame of the container. It applies pressure to the container frame via the frame engaging member but remains acting vertically. 
     In another preferred embodiment the positioning member comprises a threaded member engaged with a threaded aperture connected to said second portion. 
     In a further preferred embodiment the threaded aperture is connected to said body. 
     In a preferred embodiment the container frame engaging member is in use located less than 1 metre above said container corner aperture engaging member. 
     An apparatus having a height of less than 1 m is significantly smaller, and therefore easier to handle, than lifting devices of the prior art. 
     The apparatus may further comprise at least one lifting trolley engaging member. 
     By providing a lifting trolley engaging member the advantage is provided that a lifting trolley can be used to lift and maneuver the lifting apparatus. 
     According to another aspect of the present invention there is provided a lifting system for lifting a cuboid shipping container, the system comprising:— 
     four lifting apparatus as set out above;
 
power connection means for connecting said lifting apparatus to a power supply; and
 
at least one control device for supplying power to said apparatus so as to move said first and second portions of said lifting device.
 
     In a preferred embodiment the control device comprises at least one hydraulic fluid distribution device and said power connection means comprise a plurality of hydraulic hoses for connecting said hydraulic fluid distribution device to said lifting apparatus. 
     The control device may further comprise at least one pressure measuring device and at least one display device for displaying a weight being lifted by said lifting apparatus calculated from said measured pressure. 
     By including a pressure measuring device and converting the output of the pressure measuring device into a displayed weight, the advantage is provided that the apparatus can be used to simply weigh a shipping container to determine its weight and whether it complies with the limitations on weight for that container. 
     The control device may also further comprise a plurality of pressure measuring devices associated with each lifting apparatus and at least one display device for displaying a weight being lifted by each said lifting apparatus calculated from each said measured pressure. 
     In preferred embodiment the control device further comprises processing means for calculating a weight distribution based on each said measured pressure. 
     Measuring the weight distribution of the container can be particularly advantageous where it is important that a container is loaded with an even weight distribution as the apparatus of the present invention can be quickly used to determine whether or not a correct weight distribution has been achieved. 
     The system may further comprise a wheeled trolley having a trolley body and a pivoted lifting member with an apparatus engaging portion for engaging said trolley engaging member and a handle for applying a lifting force to the pivoted lifting member thereby lifting the apparatus for transporting. 
     The system may also further comprise wheeled members for attached to the container. 
     By attaching wheeled members to the container once it is lifted, the lifting device can then be retracted so as to lower the container onto the wheels allowing it to be easily moved. 
    
    
     
       Preferred embodiments of the present invention will now be described, by way of example only, and not and in any limitative sense with reference to the accompanying drawings in which:— 
         FIGS. 1 and 2  are front and side views of the lifting apparatus of the present invention; 
         FIGS. 3 and 4  are perspective views of the lifting apparatus of  FIGS. 1 and 2 ; 
         FIGS. 5 and 6  are perspective and front views of a shipping container being lifted by the apparatus of  FIG. 1 ; 
         FIG. 7  is a schematic representation of a lifting system of the present invention incorporating the lifting apparatus of  FIGS. 1 to 4 ; 
         FIGS. 8 a  and 8 b    are perspective views of a trolley forming part of the system of the present invention respectively showing the apparatus of  FIGS. 1 to 4  in lifted and lowered conditions; 
         FIGS. 9, 10 and 11  are perspective, plan and front views of a wheel attachment for a container forming part of the system of the present invention; 
         FIG. 12  is a further schematic representation of a lifting system of the present invention incorporating the lifting apparatus of  FIGS. 1 to 4 ; 
         FIG. 13  is a perspective view of an alternative trolley to that shown in  FIGS. 8 a    and  8   b;    
         FIG. 14  is an end of a partial cutaway view of the apparatus as shown in  FIG. 1 ; 
         FIG. 15  is a perspective view of a control panel used in the system of  FIG. 12 ; and 
         FIGS. 16 a  and 16 b    are perspective views of an embodiment of the system shown schematically in  FIG. 12 . 
     
    
    
     Referring to  FIGS. 1 to 7 , a lifting apparatus  10 , for use in a lifting system  12  for lifting a cuboid intermodal or shipping container  14 , is primarily shown in  FIGS. 1 to 4 . The apparatus  10  includes at least one lifting device, in the form of a hydraulic cylinder  16  which has a first portion, in the form of a piston  18  and a second portion in the form of cylinder barrel  20 . By the introduction of hydraulic fluid under pressure, the piston  18  moves relative to the barrel  20 . The piston  18  has, either formed as part of it or attached to it (fixedly or non-fixedly) a ground surface engaging member in the form of foot plate  22 . An example of a hydraulic cylinder  16  which is used in the lifting apparatus  10  is a single acting cylinder with a maximum lift capacity of 25 tonnes and a stroke length of around 360 mm. 
     The cylinder  16  is attached to a body  24  of apparatus  10 , which provides a frame to which other components of the apparatus are attached. The cylinder  16  is attached to the body  24  by engaging an external thread on cylinder barrel  20  with a matching internal thread in a base plate  26  of body  24 . As well as the base plate  26 , the body  24  has side walls  28  and  30 , which are connected to either side of the base plate, and connecting members  32 ,  34 ,  36  and  38  which also connect the two side walls, with the connecting members  32  and  34  also attached to the base plate  26 . This arrangement of the components of body  24  forms a frame to which the other components of the apparatus  10  are attached. 
     One of these attached components is a container corner aperture engaging member or locking member  40 . This component engages with an aperture  42  in the corner block  44  of the shipping container  14  by extending into the aperture  42 . The locking member  40  extends through connecting member  34  of body  24  and bears the weight of the container  14  when it is lifted. As a result the weight is transferred through the body  24  and into the hydraulic cylinder  16  by virtue of the body  24  and the cylinder barrel  20  being fixed to each other. The locking member  40  has a rod portion  46  and a flange  48 . The rod portion  46  has a circular cross section, is closest to the body  24  and, when the apparatus is in use, acts to carry the weight of the container  14 . The flange  48  is oval and is shaped to match the aperture  42  in corner block  44  of container  14 . The locking member  40  is rotatable about the axis of rod portion  46 . This rotation is achieved by the movement of a sliding bar  50  which has a handle  52  and which extends through a pair of apertures in the sidewalls  28  and  30  of the body  24 . A slotted aperture  54  is provided in slide bar  50  and a lever  56 , which is connected to locking member  40 , extends into the slotted aperture (see  FIG. 14 ). As a result, the sliding movement of sliding bar  50  pulls lever  56  causing the rotation of the locking member  40 . The locking member  40  rotates between a first condition, in which the oval flange  48  is aligned vertically and therefore can freely move into and out of the similarly aligned aperture  42  in corner block  44 , and a second condition, in which the oval flange is aligned horizontally and therefore cannot move into or out of the aperture in the corner block. Therefore in use the locking member  40  is initially rotated into the first condition so that the flange  48  can pass into the corner block  44 , the locking member is then rotated and the flange  48  prevents the locking member  40  from being removed from the corner block  44  thereby maintaining the apparatus  10  in engagement with the shipping container  14 . Once in the locked condition a sliding lock  58  slides into a slot in sliding bar  50  adjacent the handle  52  which prevents the handle being moved. The sliding lock  58  is sprung loaded so that it must be lifted out of the slot in sliding bar  50  before the bar can be moved. 
     A further component of the apparatus  10  is a container frame engaging member  60  which is connected to the body  24  via connecting member  38 . The frame engaging member  60  has a frame contact member in the form of disc  62  and a positioning member  64  which is an externally threaded member attached to disc  62  and extending through a mutual internal thread formed in connecting member  38 . This thread extends horizontally through the connecting member  38  and allows, by rotation of a hexagonal head  66  formed in the end of the positioning member  64 , the frame engaging member  60  to be moved towards and away from the frame of the container. The frame engaging member  60  is located above the locking member  40  and these two components are separated by distance of less than 1 m and this distance is more preferably less than 500 mm making the total height of the apparatus 480 mm. 
     The lifting apparatus  10  forms part of the lifting system  12  which includes three other apparatus  10  with one for location in each corner of a shipping container  14 . With each cylinder being able to lift 25 tonnes, the system with a device attached to each corner of a container can lift 100 tonnes (which is more than three times the capacity of a 20 ft container) to a height of around 360 mm. Each apparatus  10  is connected via a hydraulic hose  68  to a control panel  70  which controls the flow of hydraulic fluid from a pump  72 . Within the control panel is a manifold  74  which splits the single flow from pump  72  into four separate flows for each hose  68 . In the simplest arrangement the flow of hydraulic fluid and pressure to each of the lifting apparatus  10  is equal causing a uniform lift of the shipping container  14 . However, each outlet from the manifold  74  has a flow controller allowing the pressure and flow rate to each lifting apparatus to be varied which can be used to accommodate lifting a shipping container on uneven ground. Downstream of the manifold  74  are four pressure sensors  78  one connected to each of the lifting apparatus  10 . These pressure sensors  78  are used to determine the pressure of the hydraulic fluid within each cylinder and this pressure can be used to determine the weight being carried by each of the lifting apparatus  10  using the following formula: 
     
       
      
       W=P 
       m 
       ×W 
       Max 
       /P 
       O  
      
     
     where: W is the weight being lifted by the cylinder (or system);
         P m  is the measured pressure of the cylinder (or system);   W Max  is the maximum lift of the cylinder or system (which is four times the maximum lift of the cylinders);   P O  is the operating pressure of cylinders.       

     For example, for the system  12  described above with four apparatus  10  each having a cylinder  16  with a maximum lift capacity of 25 tonnes and the operating pressure of the system and each cylinder is 700 bar (70 MPa). Therefore, if each gauge is reading 175 bar (17.5 MPa) then the weight being lifted by each cylinder is (175×25)/700=6.25 tonnes. The total weight being lifted by the system (that is the weight of the container) is measured by adding each of the weights lifted by each apparatus (that is, 4×6.25=25 tonnes). In this example because each gauge is showing the same reading the distribution of weight within the container must be even. However, if the weight within the container is not evenly distributed the four gauges will give different readings resulting in different weights being calculated for each cylinder. These weights can be used to calculate the centre of gravity of the container which is particularly useful where a container is being lifted by suspension for example by a crane or helicopter. 
     In addition or as an alternative, a single gauge can measure the hydraulic fluid pressure before it is split by the manifold and by applying the same formula the weight of the container can be determined in a single calculation (although the centre of gravity of the container cannot be determined). In the above example the total maximum lift capacity of the system is 4×25=100 tonnes, the operating pressure of the system is the same (700 bar, 70 MPa) and the measured pressure of the system again 175 bar (17.5 MPa). Thus applying the above formula the total weight being lifted would be (175×100)/700=25 tonnes. Each of the sensors  76  may have its own display for the individual weights and total weight can be displayed on a display device  80  which can also be used to display the centre of gravity if calculated. 
     One of the main purposes for using the lifting system  12  is to lift the shipping container  14  to a sufficient height so that some form of wheels can be attached. This could be by the placing of one or more wheeled trolleys under the shipping container. Alternatively, the wheeled attachment devices  82  shown in  FIGS. 9 to 11  are also suitable for attachment to the container  14 . These attachment devices  82  have pairs of wheels  84  which are attached to a first body portion  86  which is itself rotatably mounted to a second body portion  88 . A locking member  90 , which is very similar in construction to locking member  40 , is provided on the second body portion  88  and is used to mount and fix the attachment devices  82  to the base corner blocks  44  of shipping container  14 . The attachment device  82  shown in  FIGS. 9 to 11  is for the front left hand corner block of the container  14  (as you face the container). A similar attachment device is provided for the right-hand front corner block but this attachment devices are mirror-image of the one shown in  FIGS. 9 to 11 . Once both in position a tying rod is used to connect the apertures  89  and a V-shaped arrangement of rods connects the two front apertures  91  allowing the container to be towed via the apex of the V. Similar attachment devices are provided for the rear corner blocks. However, these do not require the apertures  89  and  91  and the first and second body portions  86  and  88  need not be rotatable and can be fixed. 
     The total weight of the lifting apparatus  10  is around 50 kg and therefore for ease of maneuvering a wheeled trolley  92  is provided. Referring to  FIGS. 8 a  and 8 b   , the trolley  92  has wheels  94  and a frame  96  with an upstanding portion  98 . Attached to the frame  96  is a pivoting lifting member  100  which pivots about a point  102  on upstanding portion  98 . An apparatus engaging member  104  that is attached to lifting member  100  engages a trolley engaging member  106  on the barrel of the cylinder of the apparatus  10 . An alternative embodiment of the trolley  92  is shown in  FIG. 13  with components that are functionally equivalent to those shown in  FIGS. 8 a  and 8 b    identified with like reference numerals. 
     Operation of the lifting system  12  will now be described. Using the trolley  92 , a lifting apparatus  10  is moved into engagement with shipping container  14 . Each corner block  44  of shipping container  14  has two accessible apertures  44  and it is preferably the apertures on the long sides of the shipping container that are used in the lifting operation. The locking member  40  is rotated into the unlocked position with the oval flange  48  arranged vertically, as shown in  FIGS. 1 to 4 . The flange  48  is therefore aligned with the aperture  42  and the locking member  40  can be inserted into aperture  42 . Handle  52  is pulled causing sliding bar  52  slide within the apertures in body  24  which in turn causes the lever  56  to rotate the locking member  40  through 90°. This rotation of the flange  48  means that the oval of the flange is now perpendicular to the oval of the aperture  42  preventing the lifting apparatus  10  being disengaged from the shipping container  14 . 
     The frame engaging member  60  is moved into engagement with the frame of the container by rotation of the hex head  66  rotating the threaded positioning member  64  within the threaded aperture of connecting member  38  so that the disc  62  touches the frame of the shipping container  14 . The standard formation of a cuboid shipping container includes a frame formed from square cross-section tubular steel defining the edges of the container. It is this frame which the engaging member  60  touches as it is sufficiently rigid to withstand the force applied to it by the lifting apparatus. 
     This process is repeated for each of the lifting apparatus  10  so that an apparatus is in each corner of the shipping container  14 . The hydraulic hoses  68  are then connected to the hydraulic cylinder  16  in each of the lifting apparatus  10  and to the control panel  70 . Hydraulic fluid under pressure is provided from pump  72  via the manifold  74  in control panel  70  through each of the hydraulic hoses into each of the lifting apparatus  10 . This causes the piston  18  to move out of the cylinder barrel  20  and pushing on the foot plate  22  results in the upward movement of the cylinder barrel together with the body  24 , locking member  40 , frame engaging member  60  and the shipping container  14 . Because the piston  18  and the foot plate  22  are not directly below the point where the weight of the shipping container is being carried by the apparatus  10 , that is on the rod portion  46  of locking member  40 , a turning moment is produced which forces the frame engaging member  60  against the frame of the shipping container  14 . As a result, it is the weight of the container which helps to stabilise the fixing of the lifting apparatus  10  with the shipping container  14 . 
     As soon as the container  14  is no longer in contact with the ground the pump  72  can be stopped and the pressure of the hydraulic fluid in each of the lifting apparatus  10  can be measured by the pressure sensors  76  in control panel  70 . This can be used to display a total weight of the container and its contents and can also be used to calculate a weight distribution. 
     Further hydraulic fluid from the pump  72  can be used to raise the shipping container  14  higher to the maximum extension of the hydraulic cylinder  16 . If the purpose of lifting the shipping container  14  is to move it, once sufficient height has been achieved suitable wheels can be attached to the container. These can either be in the form of one or more trolleys or the wheeled devices  82  can be attached to the corner blocks  44 . Because each corner block has two apertures the wheeled devices  82  can be attached to the apertures in the corner blocks on the ends of the container  14  whilst the lifting apparatus  10  remain engaged in the apertures on the long sides of the container. Once the wheels are in place, the container can be lowered and as the wheels  84  engage the ground it is the wheeled attachment devices  82  that take the weight of the shipping container. Further retraction of the pistons  18  into the hydraulic cylinders&#39; barrels  20  keeps them free from interference with the ground. The containing 14 can now be maneuvered and this is preferably achieved by towing using a suitable vehicle. 
     Once the container is in the new location the pump  72  can be reactivated to extend the pistons and lift the container off the wheels. The wheeled devices  82  can be removed and the container lowered back into engagement with the ground. 
     To release the locking members  40  from the corner blocks  44  the slide bar  50  is returned to its original position. Pushing the handle  52  back is achieved by lifting the sliding lock  58  from the slot in sliding bar  50  thereby freeing the sliding bar  50  to move back into the position shown in  FIGS. 1 and 4 . This movement, and the resultant movement of lever  56 , causes rotation of the locking member  40  back to the unlocked position so that the oval flange  48  is aligned with the oval aperture  42  in corner block  44 . The apparatus engaging member  104  on trolley  92  can be brought back into engagement with the trolley engaging member  106  on lifting apparatus  10  and the lifting apparatus can be removed from engagement with the shipping container. 
     An alternative embodiment of the system shown in  FIG. 7  is represented schematically in  FIG. 12 . Components that are functionally equivalent to those shown in  FIG. 7  have been identified with like reference numerals and some of these components are also shown in  FIGS. 15, 16   a  and  16   b . Hydraulic fluid is provided under pressure from the hydraulic pressure unit  72  into the manifold  74  via an input line  120  and returning fluid is received back in the hydraulic pressure unit via a return line  122 . On a control panel  150  (see  FIG. 15 ) of the manifold  74  are a series of five control switches in the form of leavers  124 ,  126 ,  128 ,  130  and  132 . Four of the levers,  124 ,  126 ,  128  and  130 , directly control the four apparatus  10  allowing each cylinder of the apparatus to be controlled separately thereby individually raising and lowering a corner of the container  14 . The fifth lever  132  is connected to all four apparatus  10  via a series of restrictors  134 ,  136  and  138 . The fifth lever  132  is therefore used to lift all four corners of the container  14  at the same time and the arrangement of restrictors ensures that the container is lifted evenly even if the centre of gravity of the container is closer to one corner of the container than the others. A series of gauges  140 ,  142 ,  144 ,  146  and  148  are used to display the weight that the hydraulic cylinders  16  are with the gauges  140 ,  142 ,  144  and  146  showing the weight being borne by each of the cylinders individually and the gauge  148  (shown on  FIG. 15 ) showing the weight being borne by the whole system. The gauges are standard pressure gauges familiar to person skilled in the field of hydraulics and suitably connected to the system. These gauges have been calibrated to display weights with the dials labelled with weight rather than hydraulic pressure. 
     In  FIG. 15  an operator&#39;s control panel  150  is shown which includes the control levers  124 ,  126 ,  128 ,  130  and  132  as well as the gauges  140 ,  142 ,  144 ,  146  and  148  previously referred to. Also included in the control panel  150  are a key operated locking device  152  and an emergency stop button  154 . As shown in  FIGS. 16 a  and 16 b   , the control panel  150  forms part of the whole system  12 . A base  156  is provided on short support legs  158  between which are spaces that can be accessed by the forks of a forklift truck allowing the system  12  to be easily moved to where it is required. The hydraulic power unit  72  is located beneath the control panel  150  and the four apparatus  10  are also located on the base  156  and oriented so that a trolley  92  can easily lift each apparatus  10  from the base for maneuvering into position around the container  14 . 
     It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the protection which is defined by the appended claims. For example, the apparatus may utilise any suitable pump for creating the hydraulic pressure required to power the hydraulic cylinders. This can include electrically driven pumps, pumps driven directly from internal combustion engines, hand pumps and pumps driven by compressed air for example from a vehicles compressed air system. Furthermore, the apparatus may utilise any lifting device using a method other than the hydraulics described above. Stabilising flanges may be added to the sides of the apparatus  10  which extend from one of the sides  28  and  30  and in used extend around the side of the frame providing further stabilisation to the apparatus when the container is lifted from the ground. Similar stabilising flanges can be added to the wheeled devices  82 .