Patent Publication Number: US-3876094-A

Title: Method for stacking casting pigs into bundles

Description:
United States Patent 1 1 ()janen et a1.  
 1 1 METHOD FOR STACKING CASTING PIGS INTO BUNDLES [75] Inventors: Asko Einari Ojanen; Tor-Leif Johannes Huggare. both of Kokkola Finland [73] Assignee: Outokumpu Oy,Outokumpu Finland 221 Filed: Jan. 22, 1973 2| App1.No.:325,442  
 [30] Foreign Application Priority Data Jan, 27, 1972 Finland 221/72 [52] US. Cl. 214/152; 198/235; 214/6 P [51] Int. Cl. H 865g 57/24 [58] Field of Search 214/6 P, 6 FS 6 N. 6 A. 214/6 H,10.55, 152; 198/235 [56] References Cited UNITED STATES PATENTS 3.442.401) 5/1969 Roth et al U 214/6 P 3.587.876 6/1971 Dahlcm et all 1 .v 214/6 P 3,670.9(16 6/1972 Miller. Jr. et a1 1 u 214/6 P 3.757.966 9/1973 Cox et al 214/6 FS Apr. 8, 1975 FORElGN PATENTS OR APPLICATIONS 1.154.218 6/1969 United Kingdom 214/6 P Primary Examiner-Albrt J. Makay Assistant E.\&#39;mninerLeslie J. Paperner Almrne Agent, or FirmBrooks Haidt &amp; Haffner 5 71 ABSTRACT A method and device for stacking casting pigs into casting pig bundles containing casting pig layers of four casting pigs each and assembled in two different manners are disclosed. In the method the casting pigs are carried in spatially controlled succession to each other along a conveyor to thrust against a stop plate at the outlet end of the conveyor and part of the casting pigs which have been stopped by the stop plate are transferred laterally away from the conveyor. whereafter the pigs that have been laterally transferred optionally after a turn of 90 in a horizontal plane are pushed in a direction substantially perpendicular towards the casting pig conveyor or a hypothetic extension thereof in order to assemble a casting pig layer, and finally the assembled casting pig layer is transferred to a stacking station.  
 10 Claims, 9 Drawing Figures METHOD FOR STACKING CASTING PIGS INTO BUNDLES BACKGROUND OF THE INVENTION l. Field of the Invention The invention relates to the field of stacking casting pigs into bundles containing casting pig layers of four casting pigs each and assembled in two different ways.  
  2. Description of the Prior Art Previously known is a device of the above type in which a lifting and transferring device has been fitted above the outlet end of the casting pig conveyor to transfer one pair of casting pigs at a time with their long sides against each other to a bundle conveyor fitted immediately behind the pig conveyor on the same straight line. The stack is assembled layer upon layer on the bundle conveyor. The lifting and transferring device can be turned 90 around its vertical axis to turn the casting pigs when so desired, in which case pig layers assembled in two different manners can be obtained.  
  In this previously known device, the casting pigs are transferred in pairs from one conveyor to the other. The casting pigs are fitted in place in the layer on the second conveyor with a lifting and transferring device. The previously known methods of stacking casting pigs have several disadvantages, such as:  
 they are relatively slow, for example when using pigs of some 25 kg they are limited to a rate of about 12 tons per hour, one and the same operation unit must do several different stages of work, thereby limiting the rate of the other units, the transfer from one conveyor to the other takes place by lifting the pigs into the air, which creates great mass forces owing to the high speed, and it is difficult to obtain a satisfactory structure, the casting pigs are placed into layers by dropping them freely, which causes the disadvantage that the formed bundle tends to become too loose and at higher speeds uneven, the known systems are based on gripping the casting pigs and lifting them upwards, which requires that the pigs be highly identical in order that the gripping and dropping can always take place in the same manner, the known systems are very sensitive to the positions of the casting pigs at the gripping point, for even the smallest deviation will cause an uneven grip which either completely prevents the lifting or causes the bundle to become loosely stacked, in the known systems it is not possible to turn the topmost layer of casting pigs in a bundle upside down automatically because the shape of the pigs prevents gripping a casting pig situated on a plane.  
 SUMMARY OF THE INVENTION According to the invention the casting pigs are transferred in a spatially controlled succession along substantially straight track to impinge against a stop plate at the end of the track, at least some of the pigs being transferred laterally away from the track, whereafter the pigs which have been moved aside and possibly turned 90, are transferred in a direction essentially perpendicular towards the casting pig track or a hypothetic extension in order to assemble one of the casting pig layers, and finally the assembled casting pig layer is transferred to a stacking station.  
  Due to the invention there is provided a method and device for stacking casting pigs, a method and device in which a high stacking rate (e.g. 20 tons per hour, casting pigs of 25 kg) is highly possible because the different operational steps can overlap in the device,  
 in which a high rate is obtained with relatively lightweight devices because the partial operations are short and, when the mass to be transferred grows, the movement can be slowed down respectively,  
 in which difficulties do not arise when the pigs are slightly unidentical because the device is based on thrusts towards stop plates,  
 in which the formed bundle of casting pigs will be tight and uniform because each layer is stacked tightly as a separate entity and the layer is not allowed to disperse at any transferring stage,  
 in which slight obliquity in the arrival of the casting pig on the stacking table will not cause difficulties because the obliquities are eliminated by horizontal thrusts,  
 in which the method of stacking makes possible an automatic turning of the topmost layer.  
 DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a side view of a bundle of casting pigs stacked by the method according to the invention,  
  FIG. 2 shows a frontal view of the same bundle of casting pigs as FIG. 1,  
 FIG. 3 shows a section along line IIIIII in FIG. 1,  
 FIG. 4 shows a section along line IVIV in FIG. 1,  
  FIG. 5 shows a view from above of a special arrangement table used in the application of the method according to the invention,  
  FIGS. 6 and 7 show the same arrangement table as FIG. 5 but from behind and from the sides,  
  FIG. 8 shows a side view of the cooling. stacking, weighing, binding and storage system for casting pigs, and  
  FIG. 9 shows a view from above of a system according to FIG. 8.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT Pigs which have been cast emerge from casting machine 7 (FIGS. 8 and 9) at the temperature of 300C onto steel mesh belt 8 which has been provided with dogs and regulatable brakes text let a casting pig forward only after it has been seized by a dog. The brakes thus guarantee that the casting pigs are transported by the conveyor at controlled intervals. Water nozzles above the conveyor cool the casting pig to the desired temperature. Hood 9 and a suction apparatus above the conveyor remove the steam produced during cooling. The plate under the mesh belt is perforated so that unvaporized water can flow into container 10 underneath and from there into the drain. After the casting pig has passed the hood a sharp compressed air spray is directed at it to remove surplus water from the top of the p Steel mesh conveyor 8 brings the pigs to arrangement table 11. Descending are 12 installed between the table and the conveyor guides the pigs onto the arrangement table against stop plate 13.  
  Foot pigs la-4a and the 32 normal casting pigs following arrive on the arrangement table in the position in which they come from the conveyor. But the four last pigs of the bundle are turned text side upwards in the manner shown in FIGS. 1 and 2. The text side of the pigs at the top of the stack is accordingly visible so the instription, for example, the producer&#39;s name, metal content and weight of the pig, etc., forming the text can be read.  
  As can be seen from FIGS. 1-4, a casting pig bundle is formed from several casting pig layers one on top of the other, each layer containing four pigs, for example. 1b-4b. Every second layer of pigs has been assembled in a different manner with the result that the casting pig bundle contains casting pig layers assembled in two different manners (FIGS. 3 and 4). An exception is formed by the topmost layer which has been assembled in the same manner as the layer second to the top. In addition, pigs 5 of the topmost layer have been turned upside down so that the text side is visible. The undermost pigs are so-called foot pigs which facilitate the handling of the bundle on, for example, a cart.  
  The first foot pig, 1a, coming from cooling conveyor 8 stops against stop plate 13 on arrangement table 11. At this time cylinder 14 receives an impulse and steel bar 15 attached to the end of the piston of the cylinder moves pig 1a to the side until the other end of the pig reaches stop plate 16 at the edge of the table. Cylinder 14 remains in this position until casting pig has arrived on the table. Cylinder 14 receives an impulse to transfer pig 2a to the other edge of table 11. Simultaneously cylinder 17 receives an impulse to push pig 1a forward on table 11 for a distance of its stroke length. Cylinder 17 returns immediately. Thereafter pig 3a has arrived on the table and cylinder 14 pushes it again in front of cylinder 17. At the same time cylinder 18 pushes pig 2a forward for the distance of its stroke length and returns immediately. In the meantime pig 4a has arrived on table 11. Cylinder l4 pulls it in front of cylinder 18, cylinder 17 pushes pig 3a forward for the distance of its stroke length, at which time pig 3a pushes pig la in front of it towards stop plate 19 at the edge of table 11. When the first pig of the next layer has arrived on the table, cylinder 14 pushes it in front of cylinder 17. Simultaneously, cylinder 18 pushes pig 4a forward for the distance of its stroke length. At this time pig 4a pushes pig 2a in front of it until the latter reaches stop 20 at the edge of the table. Cylinder 18 returns immediately and cylinder 14 also returns.  
  When casting pigs 1a and 3a, 2a and 4a are in pairs at opposite sides of table 11 and cylinder 18 has returned after bringing pig 4a, cylinders 21 (2 of them) simultaneously receive impulses to push pigs la, 2a, 3a, and 4a to the center of table 11. The lowest layer has thus been formed.  
  To remove the layer, transfer device 22 above table 11 has been moved to its place by cylinder 23 even before the formation of the undermost layer on table 11.  
  When cylinders 21 have pushed the pigs to the center of the table, vertical cylinder 24 of transfer device 22 receives an impulse to descend and cylinders 21 return. Cylinder 24 lowers transfer plate 25 on the top of the pigs and cylinder 23 receives an impulse to push the pig layer onto stacking sheet 26 (FIG. 9).  
  When the transfer has taken place, transfer cylinder 27 of stacking sheet 26 receives an impulse to draw the sheet away from under the pig layer. Transfer device 22 rests on the pigs all the time. They are transferred onto hydraulically operated weighing plate 28 underneath. Transfer plate 25 follows them until descending weighing plate 28 is at such a height that stacking sheet 26 can return onto the pig layer. At this time transfer de vice 22 gives an impulse to the hydraulics and the de scent ceases. Simultaneously, vertical cylinder 24 of transfer device 22 lifts device 22 and cylinder 23 draws transfer device 22 onto arrangement table 11 to be ready for the next transfer.  
  When the casting takes place at the maximum rate. the first pig of a layer according to FIG. 3 arrives on the stacking table 4.5 seconds after the arrival of the last pig of the previous layer.  
  Cylinder 14 pushes pig 1b in front of cylinder 17 and returns immediately. Cylinder l7 pushes pig 1b forward for the distance of its stroke length and returns immediately. When pig 2b has arrived on table [1, cylinder 14 pushes it in front ofcylinder 17 and cylinder 14 returns. Cylinder 17 pushes pig 2b forward for the distance of its stroke length. Fig 2b collides with pig 1b and the two are pushed against stop plate 19 at the edge of the table. Cylinder 17 returns and assembling cylinders 21 receive impulses and push pigs 1b and 2b towards the center for the distance of their stroke length. Assembling cylinders 21 return. Pig 3b has arrived on table 11. Cylinder l4 pushes it in front of cylinder 17 and remains waiting until pig 4b has arrived.  
  When casting pig 3b has arrived in front of cylinder 17, vertical cylinder 30 of turning device 29 receives an impulse to lower turning device 29 on top of pig 312. When pig 4b has arrived, cylinder 14 transfers it in front of cylinder 18. Simultaneously, horizontal cylinder 31 of turning device 29 receives an impulse to turn pig 3b and vertical cylinder 33 of other turning device 32 receives an impulse to descend upon pig 4b.  
  When pig 3b has been turned, cylinder 30 lifts turning device 29 and cylinder 31 returns it to the correct position for the next turning. When cylinder 30 is in a raised position, cylinder 17 receives an impulse and pushes pig 3b in front of it towards stop plate 19 at the edge of the table, next to pigs lb and 212.  
  When the first pig of the following layer has arrived on the table, cylinder 14 pushes it in front of cylinder 17. Simultaneously, horizontal cylinder 34 of turning device 32 receives an impulse to turn pig 4b 90. Thereafter, cylinder 33 lifts turning device 32, cylinder 34 returns it to the correct position for the following turning, and cylinder 18 pushes pig 4b against stop 20 at the table edge. Simultaneously with the return of cylinder 18, cylinders 21 receive an impulse and simultaneously push all pigs to the center of the table. A layer according to FIG. 3 has been formed.  
  The transfer of the layer to the weighing table takes place as has been described above.  
  When the last four pigs of the bundle approach the arrangement table 11 by way of the cooling conveyor 8, stop means associated with the descending arc 12 moves to an elevated position to stop each pig in front of a photocell. The stop means can suitably be in the form of two parts vertically movable into and out of the path of the pigs to stop the pigs in a known manner. When the photocell senses the presence of a pig an operating signal is fed to the turning cylinder wh ch, by an arching and pushing motion, turns the pig upslde d The removal of the turned-over pig from in front of the photocell results in an automatic signal that the pig has been turned over.  
  When all the 10 layers of the casting pig bundle have arrived on weighing plate 28, the table is lowered further to the weighing position (FIG. 8) and weighing takes place.  
  After the weighing, horizontal cylinder 36 (hydraulic) of lifting device receives an impulse and pushes lifting fork 37 under the stack. Thereafter, hydraulic vertical cylinder 38 of the lifting apparatus receives an impulse and the table returns to the initial height. Simultaneously, vertical cylinder 38 receives an impulse and lifts the stack so much that horizontal cylinder 36 can transfer the stack to the side of scales 28. At this time the cylinder of the stacking table receives an impulse and the table rises back to the initial height. Simultaneously, vertical cylinder 38 receives an impulse and lifts the stack to such a height that horizontal cylinder 36 can move the former on storage conveyor 39. Here vertical cylinder 38 receives an impulse and lowers the stack on storage conveyor 39. Horizontal cylinder 36 draws fork 37 away and storage conveyor 39 receives an impulse to move forward. When conveyor 39 has moved so much (4 times) that the stack of casting pigs has entirely passed lifting device 35, horizontal cylinder 36 transfers lifting device 35 between stacking table 11 and storage conveyor 39. Thereafter, vertical cylinder 38 lowers fork 37 so as to be ready to take the next stack.  
  The binding takes place with steel bands 6 in the manner shown in FIG. 1. The binding is carried out with one automatic binding machine which receives its impulses from storage conveyor 39. The casting pig stack is thus always transferred to the right place for binding.  
  Stop plate 13 can be advantageously fitted so that it can be moved away from in front of the pig track, in which case two casting pigs are first allowed to collide with stop 13, whereafter stop 13 is moved aside and the pigs are transferred in pairs with their long sides against each other rectangularly between assembly cylinders 21 of the assembly station. The transfer can be carried out with transfer plate 25. Thereafter, the pigs turned with turning devices 29 and 32 are fitted to both ends of the pair of pigs with assembly cylinders 21 and a layer according to FIG. 3 is obtained.  
  A layer according to FIG. 4 can be assembled so that two pigs are first allowed to collide with stop 13, at which time a pair of pigs is obtained in which the pigs, for example In and 3a, have their long sides against each other. Pig pair 1a, 3a is then moved with cylinders 14 and 17 against stop plate 19 and the other pair of pigs 20, 4a is transferred with cylinders 14 and 18 against stop plate 20. Finally both pairs of pigs, la, 3a and 2a, 4a, are assembled by cylinders 21 into a layer according to FIG. 4.  
 What is claimed is:  
  l. A continuous method of stacking casting pigs to form casting pig bundles containing casting pig layers with four casting pigs in each layer, the casting pigs of said layers being assembled into two different patterns, a first pattern wherein all of the pigs are longitudinally aligned and a second pattern wherein one pig runs across each end of a pair of longitudinally oriented pigs, comprising carrying the casting pigs at a controlled distance from each other along an essentially straight track to collide with a stop plate at the end of the track, pushing at least some of the pigs which have collided with the stop plate laterally away from the casting pig track against a stop, whereafter the pigs which have been pushed laterally aside are first pushed in a direction essentially parallel with the track against another stop and secondly pushed essentially perpendicularly to the direction of the casting pig track to assemble one of the casting pig layers, turning some of the pigs after the first lateral pushing operation, and finally transferring the assembled casting pig layer to a stacking station.  
  2. A method according to claim 1, wherein a casting pig layer assembled in said first pattern is formed by transferring laterally two pigs with their long sides facing each other and by fitting two pigs with their long sides facing each other to replace the former, whereafter the first pair of pigs is put together with the latter.  
  3. A method according to claim 1, wherein a layer of casting pigs assembled in said second pattern is formed by transferring two end pigs to the opposite sides of the casting pig track, by turning these end pigs 90 on a horizontal plane and by moving said end pigs towards a pair of intermediate pigs having their long sides facing each other.  
  4. A method according to claim 1, wherein a casting pig layer assembled in said first pattern is formed by laterally displacing two pigs with their long sides facing each other and then pushing onwards in a direction es sentially parallel to the casting pig track to an assembly station fitted behind the stop plate, and then transferring the other two pigs of the layer with their long sides facing each other to the assembly station, whereafter the casting pig pairs are combined.  
  5. A method according to claim 3, wherein the casting pig layer assembled in said second pattern is formed by moving the turned pigs forward to a point next to the assembly station in a direction substantially parallel to the casting pig track before they are moved towards the opposite ends of the pair of pigs at the assembly station.  
  6. A method according to claim 5, wherein the casting pig pair to be positioned between the turned pigs is formed at the assembly station by moving aside two pigs with their long sides facing each other and then moving said pair of pigs forward to a point next to the assembly station in a direction substantially parallel to the casting pig track and then laterally to the assembly station.  
  7. A method according to claim 5, wherein the casting pig pair to be positioned between the turned pigs is formed at the assembly station by transferring a pair of pigs with their long sides facing each other along a straight linear continuation of the casting pig track to an assembly station fitted on the same straight line, after which the turned pigs are transferred towards each other.  
  8. A method according to claim 1, wherein a casting pig layer assembled in said first pattern is formed by transferring a first pig to one side of the casting pig track and a second pig to the opposite side of the track, whereafter the first pig is moved forward in a direction essentially parallel to the track to a point next to an assembly station fitted behind the stop plate, then a third pig is moved forward in a direction parallel to the track to a point next to the assembly station, whereafter a fourth pig is moved to the opposite side of the casting pig track and the third pig is moved next to the first pig so that their long sides face each other, then the pigs, which are in pairs on opposite sides of the assembly station, are combined into a layer at the assembly station, and the layer is finally transferred to the stacking station.  
  9. A method according to claim 1, wherein a casting pig layer assembled in said second pattern is formed by moving a first pig to one side of the casting pig track and from there forward in a direction parallel to the track to a point next to an assembly station fitted behind the casting pig track, whereafter a second pig is moved along the same track next to the first pig so that the long sides of the two face each other in a casting pig pair, a third pig is moved to one side of the casting pig track and turned, whereafter a fourth pig is moved to the opposite side of the casting pig track, then the third pig is moved forward in a direction parallel to the casting pig track to a point next to the casting pig pair, and the fourth pig is turned and moved forward in a direction parallel to the pig track to a point next to the assembly station, whereafter the pigs are transferred to the assembly station and combined into a layer which is transferred to the stacking station.  
  10. A method according to claim 1, wherein each assembled casting pig layer is transferred to the stacking station by lowering it by the height of one layer. the undermost layer of the casting pig bundle being assembled first and the topmost layer being assembled last. t I