Patent GB-829795-A (GB)
Title: Apparatus for handling cases
IPC: B65G57/00
Filed: 1957-03-26
Abstract: 829,795. Stacking articles on pallets. STEVENSON, C. H., and FOOD MACHINERY & CHEMICAL CORPORATION. March 26, 1957 [May 14, 1956], No. 9826/57. Class 94(1). [Also in Group XXX] Cases are assembled in rows on a plate 250, Figs. 1 and 2, by moving it towards and away from a case-feeding roller conveyer 52, 57, placing a row of cases on it as it finishes its movement to the right, moving it to the left and placing an abutment in the path of the cases as it commences to move right again thus displacing the row of cases to the left through the width of a row to make room for another row and repeating the movements until the desired number of rows has been formed. The plate 250 has prongs 251 projecting from one end which take between the rollers of the conveyer 57 and receive the cases thereon as the conveyer is lowered. The abutment is a bar 505, Fig. 4, attached to the side of the conveyer 57. A plate 66 on the conveyer turns them through 90 degrees when in operation and a spacing mechanism 68 varies the distances between them so that cases C in adjacent rows may be disposed as shown in Fig. 1 or in other arrangements. The underside of the plate is provided with latches 301 which remove the top pallet P from a pile and support it while the plate reciprocates. When the rows are complete, the pallet is deposited on the table T of an elevator E and the rows are swept on to it by a stop plate 58 as the plate 250 moves back to the position shown in Fig. 2. The elevator is then actuated to lower the pallet through a distance equal to the height of a case and the sequence of operations is repeated until a stack of the desired number of layers has been formed. This stack is then lowered on to a conveyer 60 which carries it out of the apparatus. A rack 253 is mounted at each side of the plate and is engaged by pinions 260 driven by a reversible motor. The plate is supported by rollers which run in guides in the framework. Each latch 310, Fig. 13, is pivotally mounted in a bifurcated hanger 306, the upper end of which is pivotally mounted in a recess near the end of a bar 303. This bar is secured by welding to the underside of the plate 250. A plate 312 welded to the latch limits its movements in the direction in which it is urged by a spring 315. A bar 308, Fig. 11 (not shown), which connects the hangers 306 is connected by springs 320 to brackets 312 on the upper face of the plate. The underside of the pallet is penetrated by projections 317 on the top surface of each latch. Spaced rollers 328 mounted on the bars 308 run on camming members 330, each of which consists of a part 330a having a vertical face and a part 330b which curves outwardly. As the table reciprocates, the rollers move on to the part 330b, but since the projections 317 are embedded in the pallet, the latches cannot swing outwards. When the pallet is lifted from the projections, the latches will swing and the pallet will be released. This occurs when the pallet is above the table T, Fig. 4, which is raised and lowered by a pair of screws 341. The table is an open framework consisting of spaced channel members 333, 334, Fig. 16, which are connected by similar transverse members 335... 340. Split nuts 383, 384, Fig. 17, mounted in the outer channels 339, 340 are engaged by power-driven screws 341, 341a. Each nut comprises two semi-cylindrical internally-threaded members 386, 387, Fig. 19, that are secured together by capacrews. The lower end of each member is formed as a flange 391 having diametrically opposite flattened side faces 392 and elongated recesses 393 adjacent to their lower edges. Each nut is disposed between plates 395 which are welded between aligned end portions 339a, 339b of the channel 339. A flat collar 399 is welded in recesses 400 in each plate 395 and is in contact with the top of the flange 391. An L-shaped member disposed in each recess 393 is secured to the undersurface of the collar 399 and prevents the nut from rotating with the screw. The table is guided by blocks 407 secured to the outer plate 395 which travel in guides 346 secured to the framework. Gears 355, 356 are keyed to the screw 341a and a gear 365 is keyed to the screw 341. A rubber belt having teeth on its inner surface is trained around the gears 355, 365 and idler gears 369. The gear 356 is driven by a motor 380 through a similar rubber belt 377. As the table approaches its lowest position, its channels pass between and outside of conveyer chains 410, 411, Fig. 16, and the stack of pallets is deposited on them. The chains 410, 411 transfer the stack to similar chains 422, 423 which in turn deliver it to a discharge conveyer 62. The conveyer 52, Fig. 22, comprises live rollers 450 mounted in a frame 451. Two rollers 450a, 450b are driven by a motor 455 through a chain 453 and sprockets 456, 457. The remaining rollers are driven from the rollers 450a, 450b through rubber belts 462, 463 that mesh with gears 464 keyed to the rollers. Since the sprocket 547 is larger than the sprocket 456, the belt 462 has a higher speed than the belt 463 and the rollers driven by it will accelerate the cases. A guide 475 is mounted along one side of the conveyer and cooperates with a guide 478 mounted to slide on transverse rods 479, 480. A member 484 is pivoted to the guide 478 to turn about a vertical axis and has a part 484 extending over the rollers and carrying guide rollers 487. An arm 490, Fig. 25, extending laterally from the guide 478 is connected by a spring 488 to the member 484. Movement of the member is limited by the engagement of a stop 489 mounted on it with a part of the guide 478. A stop plate 465 extending transversely of the conveyer is disposed between two of the more rapidly moving rollers and is mounted on a pivoted arm 466. The end of the arm is pivoted to the plunger 471 of a pneumatic cylinder apparatus 470. When the plunger moves outwards, the plate 465 is raised above the surface of the rollers to stop the cases. When a case is to be turned through 90 degrees, a plate 496, Fig. 22, is raised by means of a double acting pneumatic cylinder 495 above the upper surfaces of the rollers. The plate is disposed adjacent to an edge of the conveyer 52 and is only a fraction of the width of a case. Cases are delivered singly on to the conveyer 57 by the conveyer 52. The conveyer 57 consists of rollers 500, Fig. 26, each of which is rotatably mounted in the side members 501, 502 of a rigid frame 504. The frame is raised and lowered by a double-acting pneumatic cylinder 510 so that the top surface of the rollers may be above or below the level of the fingers 250, Fig. 4. The cylinder 510 is pivoted at 511 to the framework and its piston rod 516 is pivotally connected to one corner of a triangular plate 519. Another corner of this plate is pivoted at 520 to brackets 521, 522 mounted on the framework. The remaining corner of the plate is pivotally connected by a pin 525 to two parallel straps 526 which are secured to an arm 528. This arm projects downwardly from an angle bar 530 secured to the frame 504. Lifter arms 531...534 extend between the frame 504 and the machine framework and are pivotally connected to them. The rollers 500 are driven by a toothed rubber belt 540 which engages gears 541 keyed to them. The rollers 500a . . . 500c are not driven and retard the cases when they pass on to them. Any driven roller may be made dead by disconnecting the belt from its gear 541 and training it over the adjacent short idler roller 550. The leading case on the conveyer 57 is arrested by a channel-shaped plate 555, Figs. 4 and 27, which extends also across the part of the machine that is above the table T. The plate 555 is disposed over a similarly shaped plate 556 to which it is pivotally connected at one end by a long pin passed through both flanges of each plate and connected at the other end by studs 560 welded to the plate 556 and extending through slots in the plate 555. Nuts 563 are provided on the studs to lock the plates in any position. Spaced blocks 558 welded to the plate 556 are engaged by screws 565 and secured to them by set screws. Each screw is threaded in a sleeve 570 that is rotatably mounted in a stationary bushing 571 which is secured to the underside of a channel member 574 of the framework. Each sleeve 570 has a sprocket 581 secured to it at one end which is engaged by a driving chain 582. The position of the stop 555 depends on the type of case being handled. When a change from one type of case to another occurs, the position of the stop is determined by the closing of whichever switch SW 31 ... SW 36 is connected in the control circuit appropriate to the new type of case selected by the operator. The switches are in staggered formation and are traversed by a cam 600 when the motor 584 is energised. The position of the stripper plate 58 is adjusted by similar means. When cases in a row are to be separated from each other, a spacing mechanism 68 disposed above the conveyer 57 is put into operation. A rigid frame 604 is mounted above the conveyer and has a frame 610 adjustably mounted within it. The frames are connected by screws 618 carrying sprockets around which passes a chain 626 driven by a motor 625. A case intercepting blade 635, Fig. 31, is mounted on the frame 610 and is raised and lowered by a double-acting pneumatic cylinder 637. The position of the inner frame is adjusted to provide the spacing desired when the motor 625 is energised to actuate the screws. When this occurs a cam plate 648 mounted on the inner frame traverses the switches SW 23 .. SW 25 and closes each switch in succession. The frame stops at a point dependent on which switch was connected in the circuit selected by the operator before the operation began. A fork lift truck deposits a stack of pallets on a pair of parallel endless chains 100, 101, Fig. 6, which carries them across the machine into abutment with vertical bars 120. These bars are mounted adjus