Patent GB-941092-A (GB)
Title: Box forming machine
IPC: B65B43/18
Filed: 1960-08-02
Abstract: 941,092. Erecting boxes from collapsed blanks. R. W. ALLISON. Aug. 2, 1960 [Aug. 24, 1959], No. 26683/60. Heading B8C. A machine for erecting boxes of tubular form made of corrugated fibreboard and having end closing flaps comprises means for elevating from a loading position a stack of collapsed boxes, means for lifting successively individual boxes from the stack as they are elevated, means for expanding the boxes and for folding the closing flaps at one end, carriage means for conveying each box out of the machine after forming, and means whereby when the stack of collapsed boxes has been depleted to a predetermined number the stack is supported independently of the elevating means and the elevating means returns to the loading position where feeder means loads a new stack of collapsed boxes on to the elevating means. The machine is controlled by electric, hydraulic and pneumatic circuits and normally cycles automatically, but manual controls are provided. Stack storage and elevating means.-A storage area 45 accommodates stacks 47 (Fig. 1) of collapsed blanks and an elevating means 23 of the fork lift type raises each stack to the box expanding section 21. A frame 641 (Fig. 16) driven from a motor 669 by a chain 667 transfers a stack from rollers 635, 637 to the fork lift and a conveyer 685 driven by a motor 699 moves the succeeding stacks along so that the next stack rests on the rollers 635, 637. When the stack has been depleted to a predetermined extent, dogs 711 (Fig. 3a) forced apart by a rising stack engage and support the bottom of the stack and the lift fork is lowered to pick up the next stack. The engagement of the dogs beneath the stack operates a switch which reverses the drive to the lift fork. The fork lift is driven by a motor 609, a rack 627 and a pinion 629 on the motor shaft (Fig. 7). Box expanding and delivering means.-The top blank 27 is engaged by a suction cup 65 (Fig. 7) mounted on a shaft 67 in a cylinder 73. A vacuum system comprising a pump and an electric motor supplies a vacuum to the cup 65. Bars 221 cause the blank to square itself while being expanded by the rising cup 65. A piston and cylinder device 317 grips the top of the box between bars 227, 229 enabling the grip of the cup 65 to be released prior to a carriage comprising a plate 225 and the bars 227, 229 moving along bars 235, 237 to deliver the box to a packing machine. A piston 395 in a cylinder 397 engages one side 110 of the box to facilitate squaring. A double-acting cylinder 255 mounted on a stationary piston having hollow shafts extending in opposite directions reciprocates the carriage to and from a box delivery position. The stroke of the suction cup 65 is constant so long as the stack lift fork is rising, but when the dogs 711 take over from the lift fork the stroke of the cup increases slightly as each blank is removed, the cup 65 being stopped by engagement with the uppermost blank. Folding in end flaps.-Before delivering the expanded box the flaps at one end are folded in by means comprising a member 417 (Fig. 11) that spreads apart two end flaps 389, 407, the member being actuated by an air cylinder 413 and a spring 421 and a pin 427 holding the member 417 in the vertical position. Cylinders 453 (Fig. 10) actuate arms 433, 435 which fold flaps 385, 387 into the end plane of the box. The upper flap 389 (Fig. 13) is next folded down by a cylinder 531 and plunger 533, the plunger engaging a latch assembly 541 pivoted at 549 so that an arm 547 folds down the flap 389. When the carriage has delivered the box to a packing machine and returned along rods 235, 237 a resetting assembly engages an arm 561 on the latch assembly and resets it to the position shown in Fig. 13. An arm on the packing machine rises when a box is presented to the packer and folds up the lower flap and causes release of the box gripping mechanism and initiates return of the carriage. Control mechanism.-The various piston-andcylinder devices and the feeding and delivering means are controlled by solenoid-operated valves and by switches so arranged that the cycle is stopped if a preceding step has not taken place normally. For example, a limit switch is opened if the lift fork is empty and consequently rises too high; again, switch means prevents the stack feeder from operating if no reserve stack is present; further, the suction cup cannot rise until the carriage has returned to its initial position. The electric circuit is supplied from a three-phase 440 volt supply which drives the motors, the various solenoids being connected to a low voltage supply from a step-down transformer.