Patent Publication Number: US-2004050018-A1

Title: Method and means for forming and lifting parcels or packages comprising at least two stacks or units of goods, and an apparatus for forming such parcels

Description:
[0001] The present invention relates to a method and means for forming large parcels or packages of goods comprising a lifting sling or load carrying band that can be lifted by a lifting device. In one embodiment the invention relates to forming such parcels comprising a relatively wide band. The invention further relates to an apparatus for forming said parcels or packages.  
       [0002] The Applicants own patent application WO 98/26977 discloses a lifting sling or -belt that surrounds one pair of stacks of units of goods, where the sling is in the form of a closed loop of a belt having a width substantially equal to the transverse with of the stacks. One limitation with this solution is that the sling has a lifting eye that is located above the upper part of the goods to be lifted, and consequently there is a need for a somewhat comprehensive handling space above the goods. This implies that it is difficult to take full advantage of the loading volume of for instance containers or corresponding storage/transport equipment having a fixed ceiling. The same problem will apply when storing this type of goods in storage systems based on shelves. Hence, valuable transport/storage capacity can not easily be exploited in a rational manner, because the upper part of the loading space has to be filled manually. The apparatus disclosed in this reference for forming the sling, is in particular suited for forming a sling where the loop ends in a lifting eye above the goods to be lifted.  
       [0003] SE-B-362 860 discloses a combined lifting and strapping device to be applied at two stacks of goods, where the strap surrounds the goods and has a loop-formed part raising up between the two stacks of goods. The upper part of the loop-formed part is connected with an upper, horizontal part of the strap by means of a lifting eye. The purpose of this connection is to support the loop-formed part and to restrict same from falling down in the space between the two stacks. In lifting operations, one lifting device (hook) will in all situations be applied at a vertical level above the stacks because the lowest point of attack to a lifting ring will be at the level of the stacks plus the thickness of the lifting part of the hook itself. Followed by elongation of the strap (all materials will elongate by tension) and also by compression of the small strap into the load, the strap will be stretched and the lifting ring will be at a reasonable elevated height with respect to the stacks when the lifting hook is applied.  
       [0004] With the present invention the above mentioned disadvantages can be avoided. In accordance with the present invention it is now possible to handle goods comprising at least one pair of stacks of units of goods surrounded by a load carrying band, where the lifting point of the band is situated at a vertical level lower than the height of the goods itself.  
     
    
    
     [0005] In the following the present invention will be further described by examples and figures where:  
     [0006]FIG. 1 is a sketch showing a load carrying band surrounding two stacks of goods A and B, seen in perspective,  
     [0007]FIG. 2 is a sketch showing distribution of forces to a parcel involving the load carrying band in FIG. 1, seen in a front view,  
     [0008]FIG. 3 a  is a sketch showing the band in FIG. 2 with a reinforced intermediate section,  
     [0009]FIG. 3 b  shows in an enlarged view the reinforced intermediate section as shown in FIG. 3 a,    
     [0010]FIG. 4 shows in one embodiment an apparatus for applying the load carrying band around the goods,  
     [0011]FIG. 5 shows in another embodiment an apparatus for applying the load carrying band around the goods to be lifted,  
     [0012]FIGS. 6 a - c  shows a third embodiment for applying a load carrying band, where the ends of the band are joined after the band is brought to surround two units of goods,  
     [0013]FIG. 7 shows from above, a sketch of an installation for forming parcel with a load carrying band comprising a load carrying band applying station and two stretching/band end joining stations.  
     [0014]FIG. 8 is a sketch showing a load carrying band surrounding two stacks of goods A and B, seen in perspective where the intermediate section can be provided with an insert,  
     [0015]FIG. 9 is a sketch showing a second embodiment of a load carrying band surrounding two stacks of goods A and B, seen in perspective. 
    
    
     [0016] In FIG. 1 there is shown two stacks of goods, A and B that may comprise piles of sacks or any other type of load that can be surrounded by the band  1 , thus forming a parcel P. The band  1  is of an width appropriate for securing the load in a satisfactory manner. For some type of loads this implicates that the band has a width positively wider than the width of the load. In this manner the protruding part of the band will tend to fold inwards against the front- and back sides of the load, and consequently the goods will be better secured against spilling out of the load carrying band. In other applications the band can be more narrow than the width of the load, and several individual bands can also be applied in accordance with the invention. The band can be of any convenient material such as polyethylene, polypropylene, paper, jute etc. The band may be constituted of any type of web-material such as homogenous band, a net or woven fabric, or a band with sides of a shrinkable material, for instance a heat-shrinkable material.  
     [0017] As seen in the figure, the band is formed to surround the stacks A and B where it has an upper planar section  4 , two sides  5  and  6 , two bottom parts  7  and  8  and finally a central, vertically projecting part  9 . The central part  9  consists of a first vertical extending part of the band  10  connected with the bottom part  7 , and a second vertical extending part  11  connected with the bottom part  8 . The two vertically extending parts  10  and  11  are connected together through an intermediate section  3  in which there can be introduced a lifting device  2 . Advantageously the mutual frictional forces between the load carrying band and the goods and between parts of the band itself (section  10  and  11 ) are sufficiently high that the load carrying band will be of a self-locking nature i.e. as the goods are surrounded by the band in a proper manner, the band will rest firmly and the intermediate section  3  will be maintained in its correct position, and consequently the parcel will be stable.  
     [0018] The lifting device may be formed as a bar  2  or a rod or the like with a cross-section suitable for entering into the intermediate section  3 . It should further be understood that the parcel can be lifted by entering one bar in each ends of the intermediate section. In this sense a lifting yoke having inwardly movable lifting bars can be applied (not shown).  
     [0019] As shown in FIGS. 3 a  and  3   b , the intermediate section may be provided with reinforcement to render a secure and even force distribution to the vertical parts  10 ,  11  of the band. For instance, the intermediate section may be reinforced by a tubular elongate element  20  which is adapted to receive the lifting device  2 , whereby the lifting device can be introduced into the element  20 . The element shown in the figures has a circular cross-section, but it should be understood that any convenient cross-sectional shape may be applied. Even an U-shaped (upside down) cross-section may be applied as reinforcing element (not shown). The element shown in FIGS. 3 a - b  may be produced from any convenient material, such as cardboard paper, plastics material, metallic materials etc., depending on parameters such as price, strength and durability.  
     [0020]FIG. 2 relates to the stability of a parcel where the distribution of gravitational forces versus lifting forces is indicated. In case the two stacks A and B have the same density and volume, analyses based upon symmetry can be applied. The centre of gravity in stack A is denoted by g, where the weight is represented by the force f. Similarly with stack B, where centre of gravity is denoted by g′, the corresponding weight is denoted by f. The centre of gravity of the parcel as such will be at G, which is situated in the middle of axis  0 - 0 . At this point the total weight of the parcel is given as F′, which is equal to f+f′. In the figure the lifting force is indicated as F, and acts at a point in between the two stacks of load denoted by  3 . The distance between F′ and F is given as h. In dynamic handling conditions, i.e. lifting the parcel at  3 , the parcel can swing about an axis perpendicular to the plane of the paper. The parcel will be self-stabilizing under the condition: h&gt;0.  
     [0021]FIG. 4 shows an apparatus for applying a load carrying band  34  to the goods to be lifted/transported. The goods enter the packaging zone by a conveyor  30 , that may be an endless band conveyor. At the packaging station the conveyor has a non-driven part  33  that may be constituted by non-driven rollers  31 . At the side of the non-driven part  33  there is arranged a load carrying band  34 , which is spread out by elements or rollers  35 ,  36 ,  37 ,  38 , arranged in four corners of the band. In this embodiment the band is an endless band with a joint  39 , where its two ends are joined by welding, sewing, glueing or any other appropriate joining method.  
     [0022] A lifting or positioning device  44  comprising a plurality of forks  43  is arranged to handle the goods from the stationary position at the non driven rollers  31  into the spread-out load carrying band  34 . Undesired length wise movement of the forks  43  can be restricted by vertically movable locking plates  45 ,  45 ′ that can be retracted when the forks are activated. The positioning device is arranged to be moved both in its length wise direction and its vertical direction.  
     [0023] It should be understood that the non-driven part of the conveyor can be retracted or folded downwards in the handling operation of the goods into the load carrying band. In one embodiment the non-driven part can be constituted by two parts hinged about a horizontal axis which can manipulate the units of goods to be spread apart at their lowermost part. The purpose of this feature is to render a free space for the formation of the loop, as well as experience has shown that the units should be in firm abutment at its upper part in the loop forming operation to achieve a good stability of the parcel.  
     [0024] The loop of the band is formed by means of stretch elements or rollers  40 ,  41 . These rollers co-operate with a mandrel or roller  42  intended to be positioned below the band, and further to be elevated between the two rollers  40 ,  41 . In this elevating operation, the band will be folded upwards and form a loop in-between the two units of goods. The band length is adapted to give a firm fit, where at the same time the upper end of the loop ends below the upper part of the goods, but above the centre of gravity of the goods. In the figure these means are shown in a retracted position.  
     [0025] It should be understood that, whenever appropriate, a reinforcing element  20  can be introduced onto the mandrel before its elevating operation, thus leaving the reinforcing element in a ready-to-use condition as the mandrel is retracted.  
     [0026] Following this operation, the packaged goods will ready for further transport. In the present embodiment, the goods will be placed upon a conveyer  32  for this purpose.  
     [0027]FIG. 5 discloses an other embodiment of an apparatus for applying a load carrying band  134  around a pair of units of goods. The goods enters the packaging zone by means of a conveyor  130 , that may be an endless band conveyor. At the packaging station the conveyor has one individually driven part  133  that may be constituted by one relatively short endless belt. At the side of and above this arrangement there is arranged a load carrying band  134 , which is spread out by elements or rollers  135 ,  136 ,  137 ,  138 , arranged in four corners of the band. As in the foregoing embodiment, the band can be an endless band with a joint  139 , where its two ends are joined by welding, sewing, glueing or any other appropriate joining method. It should be understood that the band may be jointed in situ by appropriate methods.  
     [0028] A tilting device comprising a plurality of levers  143 ,  143 ′ is arranged to handle the goods from the stationary position at the part  133  in position with respect to the spreaded-out load carrying band  134 . In this position the goods will be tilted from the part  133  and onto platforms  150 ,  151 . The platforms may be arranged to swing about a horizontal axis  152 ,  152 ′ and further be swung individually about a vertical axis, the reason for which will be explained below. When the goods are in position, the load carrying band will be lowered downwards to surround the goods.  
     [0029] At one side (bottom part) of the band there is arranged a set of stretching elements or rollers  140 ,  141 . These rollers co-operate with a mandrel or roller  142  intended to be positioned at the outer side of the band, and further to be moved side wards between the two rollers  140 ,  141 . In this operation, the band will be folded side wards and form a loop in between the two units of goods. The platforms  150 ,  151  may be swinged to adjust the position of the goods with respect to this operation, i.e. forming a space in-between the two units of goods for allowing the roller  142  to pass through this space. It should be understood that the length of the band is adapted to give the band a firm fit, where at the same time the upper end of the loop ends below the upper part of the goods, but above the centre of gravity of the goods in lifting mode.  
     [0030] Following this operation the roller  142  is retracted and the packaging is tilted back on the conveyer by tilting the platforms  150 ,  151  about their axis  152 . Following this operation, the packaged goods will be ready for further transport. In the present embodiment, the goods will be placed upon a conveyer  132  for this purpose.  
     [0031] In both embodiments described above, the band may be pre-manufactured as an endless band, or it can be made in situ from an appropriate material source. In the latter case, a required length of the band will be taken from the storage that may be a spool or the like, and cut in a predetermined length. Following that the two ends of the band will be joined by sewing, glueing, welding or the like. The load carrying band can be made in situ upon the elements, or entered upon these elements after its manufacture.  
     [0032]FIGS. 6 a - c  shows a third embodiment for applying a load carrying band, where the ends of the band are joined after the band is brought to surround two units of goods. In FIG. 6 a  there is shown a load carrying band  234  having spooled ends  250 ,  251 . The band is arranged in an application unit  252 , having two inclined base platforms  253 ,  254  onto which the band is brought to rest. The platforms are arranged upon a base structure  255 . In the middle of the two platforms there is arranged in an upward manner a stationary support structure  256  onto which the load carrying band forms a loop  261 . The height of the structure  256  is lower than the actual height of the load to be handled. In the embodiment shown in the figure there is arranged a tubular element  257  on the top of the structure  256  which supports the loop, but in principle the loop may be formed without such tubular element. The structure then should have an U-shape at its top, to facilitate the entrance of a lifting device beneath the loop. The top part of the loop thus forms an intermediate section that can be served by a lifting device. Slightly above the inclined platforms and close to the support structure, there are arranged elements or rollers  258 ,  259  whose purpose is to tie-in the load carrying band in these regions. The elements  258 ,  259  can be retractably mounted upon a frame (not shown).  
     [0033] In FIG. 6 b  there is arranged two units of load A′, B′ upon the platforms  253 ,  254  respectively.  
     [0034] In FIG. 6 c  the spooled ends  250 ,  251  of the load carrying band  234  as shown in FIG. 6 a  are unwound and arranged to surround the two units of goods A′, B′. The two ends of the band are in this embodiment put together at one side of the upper part of the units of goods and joined together by a joining device  260  that may be a device for performing sewing, glueing, welding or similar joining operations. Following the joining operation of the end of the band, the elements  258 ,  259  can be retracted and the parcel P′ thus formed may be lifted by entering a lifting device into the tubular element  257 . As will be seen of the figure, the sides of the support structure  256  facing the load have a slight angular deviation with respect to the perpendicular to the base structure. This angular deviation together with the inclination of the base platforms  253 ,  254  will as such contribute to initiate a pulling force in the load carrying band as the load being lifted out of the application unit, because the two units of load then will tend to meet along their mutual sides.  
     [0035]FIG. 7 shows from above, a sketch of an installation for forming parcels (P″, P′″) with a load carrying band ( 314 ) comprising a load carrying band applying station  300  and two stretching/band end joining stations  301 ,  302 . In this arrangement, load carrying bands  303 ,  304 , are fed into the applying station from two sides. A manipulator  305  is arranged to take goods, for instance sacks  308 ,  309  arriving via a conveyor  307 , and to enter the goods into one load carrying band  314  that is arranged in advance at the applying station. In the figure piles of sacks  310 ,  311 ,  312 ,  313  are arranged into the band  314 . Following the completion of the process entering the goods into the band, the pre-formed parcel is transported to one stretching/band end joining station  301 ,  302  for further processing. The joining operation can be performed in accordance with that described under FIGS. 6 a - c . A stretching operation of the load carrying band can then be performed, and finished parcels can be lifted and transported away by a truck T, T′ or a similar transport device having appropriate lifting gear. The stretching operation can be performed by applying a lifting force for instance 2-3 times the weight of the load while restricting the load against being lifted. Due to the properties of the material (friction, stretchability etc.) the parcel thus formed can be in a state where the band can rest with a certain degree of pretension.  
     [0036] The above disclosed installation for forming parcels will be simple and at the same time have good load-handling capacity.  
     [0037] One preferred application of the invention is handling of thermal insulation materials, such as glass wool, rock wool or similar. Such products may be layered, and these layers should advantageously be oriented in such a manner that they become vertically oriented in the following lifting operation. This will render both good stability and gentle handling of the product.  
     [0038] In FIG. 8 there is shown a load carrying band surrounding two stacks of goods A and B, seen in perspective, where the intermediate section can be provided with an insert  120  similar to that of element  20  as shown in FIGS. 3 a  and  3   b . The insert  120  can be made out of a compact material, and further be placed in the intermediate section  103  (similar to that shown in FIG. 3 a ). Alternatively, the insert can be made out of a compressible material such as glass wool or rock wool. In the figure the insert has a cylindrical, elongate shape similar to that of the width of the band  104 , and is inserted as a process step when a parcel is formed. It should be understood that other appropriate elongated inserts of various cross-sections can be applied as well. By the introduction of an appropriate lifting device in the intermediate section  103 , the insert  120  will either be pressed out of said section or to the side, allowing the lifting device to pass at the side thereof. The purpose of the insert is to ease the introduction of a lifting device.  
     [0039]FIG. 9 discloses a second embodiment of a load carrying band surrounding two stacks of goods A and B, seen in perspective. In this embodiment the band surrounding the stacks has an intermediate section  203  that is formed by means of two intermediate parts  211 ,  212  of the band that are secured to the upper section of the band  204 . The intermediate parts can be secured to the upper section by means of making folds  213 ,  214  into which the upper ends of the intermediate parts  211 ,  212  are entered and further be secured by sewing  215  or any appropriate joining method. By securing the intermediate parts  211 ,  212  arranged with a predefined space between said parts, there is provided a space in the intermediate section for the introduction of a lifting device.  
     [0040] In accordance with the above standing embodiments it should be understood that the part of the band forming the intermediate section can be formed into a lifting eye by any appropriate means. The lifting gear (not shown) may then alternatively be applied to the intermediate section through a hole in the upper section of the band.  
     [0041] Further, it should be understood that modifying for instance the prior art solution as given in previously mentioned WO 98/26977 by mutually joining the similar intermediate parts of the suspension loop to form a similar intermediate section for lifting at a level below the top of the stacks and further above the centre of gravity of the parcel, will be within the scope of the invention. Such joining can be done by appropriate joining methods e.g. sewing, gluing, welding or the similar.