Automatic case stacker

Claim 2

Apparatus for arranging similar units into vertical stacks of predetermined height comprising: a. a supporting frame with parallel sides and with a horizontally-extending conveyor means thereon comprising two parallel endless conveyors, one near each side of the frame with a space between them, the frame and conveyor having a receiving end onto which units to be stacked are placed in succession and a delivery end opposite the receiving end, b. elevator means on the frame intermediate the two ends thereof and positioned in the space between the two endless conveyors, said elevator means having a platform which has a lower position over which units to be stacked are carried in succession by the conveyor means arranged to elevate each unit in turn to a selected uniform level above the conveyor means, with each succeeding unit after the first in a stack being raised underneath the one ahead until the stack comprises a predetermined number of units and is of a predetermined height, the elevator comprising also a fluid pressure-operated ram on which the platform is fixed and by which it is moved vertically, c. said frame having upwardly-extending frame members at each side thereof between which the elevator lifts the units to form a stack, the side frame members each having a unit-supporting dog thereon with the dog on one side being directly opposite the one on the other side, said dogs being movable in a vertical arc between a position where they are clear of the upward travel of the elevator platform but project under a unit raised above the level thereof by said platform to a position entirely clear of any contact with the units, there being horizontally-acting cylinder and piston units arranged to move and hold said dogs in position where they are entirely clear of any contact with the units and effecting their return to a position where they may extend under a unit that has been elevated by the platform, d. fluid pressure-actuated means controlled by the height of the stack of units above said dogs for selectively holding said dogs out of unit-contacting position whereby the completed stack may then be lowered into said conveyor means to be carried thereby to the delivery end of the conveyor.

Claim 3

Apparatus as defined in claim 1 in which said means for holding the dogs out of unit-contacting position is rendered inoperative and a pusher means iS arranged to slide each completed stack while it is supported on said dogs at an elevation above the level of the conveyor means.

Claim 4

Apparatus as defined in claim 2 where the dogs are crosswise of the conveyor means and said pusher is arranged to push the completed stack to one side of the supporting frame in a direction transverse to the direction of travel of the conveyor means.

Claim 5

Apparatus as defined in claim 1 in which said dogs each comprise a pivoted plate biased to swing to a horizontal unit-supporting position but is free to swing upwardly by contact with a unit being lifted by said elevating means, and wherein means is provided for restraining each of said dogs so biased from swinging down to the horizontal unit-supporting position, the apparatus having means actuated by contact with the stack only when the stack has reached a predetermined height for operating said restraining means to keep the dogs from swinging down to load-supporting position whereby the completed stack may then be lowered past said dogs onto the conveyor means to be carried thereby to the delivery end of the conveyor, and other means effective upon travel of the completed stack toward said delivery end for releasing said dog-restraining means whereby the dogs are restored to a free-swinging condition for the forming of the next stack.

Claim 6

Apparatus as defined in claim 1 in which the dogs and the horizontally-disposed cylinder and piston units for the respective dogs are mounted for adjustment horizontally toward and away from each other and vertically with respect to the conveyor to thereby accommodate units of different widths and different heights, the frame having transversely-adjustable longitudinally-extending guide rails at each side thereof, the adjustment of which enables units of a preselected width to be kept centered over the elevator platform.

Claim 7

The apparatus defined in claim 1 wherein said elevator platform has a depending leg element thereon which has a laterally-projecting flag switch-engaging means thereon, and a pair of vertically-spaced flag switches positioned on the frame to be operated by the movement of the projection on said leg past said switches, the upper flag switch being arranged to reverse the travel of the ram when it has reached the predetermined level above the conveyor and the lower one of which is arranged to operate a control means for passing the units one at a time to the elevator, said upper flag switch comprising the only ram-operated means for reversing the travel of the ram.

Claim 8

Apparatus as defined in claim 6 wherein the upper flag switch is vertically adjustable in the frame to adjust the extent of up and down travel of the ram.

Claim 9

Apparatus as defined in claim 1 wherein said conveying means comprises a pair of parallel endless chain conveyors driven together as a unit but spaced from each other and from the sides of the frame and there is a vertical frame structure extending upwardly from the sides of the supporting frame at each side of said unit-elevating means, the opposed dogs being supported on said vertical frame structure at each side of the frame, and means on said vertical frame structure projecting toward the receiving end of the conveyor means for folding down all the flaps of a unit which is a carton to a level below the level of the dogs so that the unit may be conveyed under said dogs onto the elevating means.

Claim 10

Apparatus as defined in claim 8 in which the dogs are vertically adjustable on the vertical frame structure and the flap closure is also vertically adjustable.

Claim 11

Apparatus as defined in claim 8 wherein the vertical frame structure has a weight slidably suspended from the top thereof in position to be engaged and lifted by the stack as it is being progressively formed and thereby exert a pressure on the closed carton flaps to hold them down while glue may be setting or if one carton is being glued atop another.

Claim 12

Apparatus as defined in claim 1 wherein said vertically-extending side frames aLso support means extending toward the receiving end arranged to fold down the flaps of a unit where such unit is a carton with flaps incompletely closed to an extent where the flaps will be at a level below the dogs when the unit moves into position over the elevator platform.

Claim 13

Apparatus for arranging similar units into vertical stacks of predetermined height comprising: a. a supporting frame with parallel sides and with a horizontally-extending conveyor means thereon comprising two parallel endless conveyors, one near each side of the frame with a space between them, the frame and conveyor having a receiving end onto which units to be stacked are placed in succession and a delivery end opposite the receiving end, b. an elevator on the frame intermediate the two ends thereof and positioned in the space between the two endless conveyors, said elevator having a platform which has a lower position over which units to be stacked are carried in succession by the conveyor means and arranged to elevate each unit in turn to a selected uniform height above the conveyor with each succeeding unit in the stack after the first one being raised underneath the preceding one until the stack comprises a predetermined number of units and is of a predetermined height, the elevator comprising also a fluid pressure-operated ram on which the platform is fixed and by which it is moved vertically, c. a vertically-movable stop means normally positioned to stop each unit as it moves in position over the elevator to be lifted, said stop means being movable from said normal position to a position out of the plane of travel of a unit supported on the conveyor means, said stop means having a first trip means thereon arranged to be operated when the stop means is in normal position by a unit which is carried by the conveyor means contacts it, said trip means being arranged to energize the ram to effect the raising of the elevator, d. elevator control means arranged to always reverse the upward travel of the elevator at the same preselected level comprising a second trip means on the frame below the elevator, and means on the elevator below the platform for operating said second trip means on the upward travel of the elevator to thereby effect the lowering of the elevator back to said lower position, said second trip means comprising the only means responsive to the travel of the elevator including any stack which it lifts for reversing the travel of the elevator, e. said frame having upwardly-extending frame members at each side thereof between which the elevator lifts the units to form a stack, the upwardly-extending side frame members each having a unit-supporting dog thereon pivoted to swing in a vertical arc with the opposing dogs positioned to clear the path of travel of the elevator platform but to be engaged and swung upwardly from a horizontal position toward a vertical position by contact with a unit being lifted by the elevator, said dogs each being biased to swing back to a horizontal position where they each project under a unit after the elevator platform has moved to a level above the tops of the supporting dogs, whereby the dogs support the bottom of each unit in turn as it is lifted by the elevator and the elevator then descends, f. a second trip means in position to be engaged by the top of the stack as the last unit is lifted into place and arranged (1) to move said vertically-movable stop and its said first trip out of unit-obstructing position, and (2) move and hold said dogs in a nearly vertical position clear of contact with the units of the stack and prevent their moving to a horizontal load-supporting position whereby the stack of units may then be lowered by the elevator platform onto the conveyor means to be carried without obstruction from said stop toward said delivery end, and g. means in the path of travel of the stack between the vertically-movable stop and the delivery end of the conveyor for restoring said stop with its first Trip means into unit-obstructing position and simultaneously release said dogs whereby they may return to their horizontal position.

Claim 14

Apparatus for arranging similar units into vertical stacks of predetermined height comprising: a. a supporting frame with parallel sides and with a horizontally-extending conveyor means thereon comprising two parallel endless conveyors, one near each side of the frame with a space between them, the frame and conveyor having a receiving end onto which units to be stacked are placed in succession and a delivery end opposite the receiving end, b. an elevator on the frame intermediate the two ends thereof and positioned in the space between the two endless conveyors, said elevator having a platform which has a lower position over which units to be stacked are carried in succession by the conveyor means and arranged to elevate each unit in turn to a selected uniform height above the conveyor with each succeeding unit in the stack after the first one being raised underneath the preceding one until the stack comprises a predetermined number of units and is of a predetermined height, the elevator comprising also a fluid pressure-operated ram on which the platform is fixed and by which it is moved vertically, c. a vertically-movable stop means normally positioned to stop each unit as it moves in position over the elevator to be lifted, said stop means being movable from said normal position to a position out of the plane of travel of a unit supported on the conveyor means, said stop means having a first trip means thereon arranged to be operated when the stop means is in normal position by a unit which is carried by the conveyor means contacts it, said trip means being arranged to energize the ram to effect the raising of the elevator, d. elevator control means arranged to always reverse the upward travel of the elevator at the same preselected level comprising a second trip means on the frame below the elevator, and means on the elevator below the platform for operating said second trip means on the upward travel of the elevator to thereby effect the lowering of the elevator back to said lower position, said second trip means comprising the only means responsive to the travel of the elevator including any stack which it lifts for reversing the travel of the elevator, e. said frame having upwardly-extending frame members at each side thereof between which the elevator lifts the units to form a stack, the upwardly-extending side frame members each having a unit-supporting dog thereon pivoted to swing in a vertical arc with the opposing dogs positioned to clear the path of travel of the elevator platform but to be engaged and swung upwardly from a horizontal position toward a vertical position by contact with a unit being lifted by the elevator, said dogs each being biased to swing back to a horizontal position where they each project under a unit after the elevator platform has moved to a level above the tops of the supporting dogs, whereby the dogs support the bottom of each unit in turn as it is lifted by the elevator and the elevator then descends, f. a second trip means in position to be engaged by the top of the stack as the last unit is lifted into place and arranged (1) to move said vertically-movable stop and its said first trip out of unit-obstructing position, and (2) move and hold said dogs in a nearly vertical position clear of contact with the units of the stack and prevent their moving to a horizontal load-supporting position whereby the stack of units may then be lowered by the elevator platform onto the conveyor means to be carried without obstruction from said stop toward said delivery end, and g. means in the path of travel of the stack between the vertically-movable stop and the delivery end of the conveyor for restoring said stop with its first Trip means into unit-obstructing position and simultaneously release said dogs whereby they may return to their horizontal position.

Claim 15

Apparatus as defined in claim 12 for arranging similar units into a vertical stack of predetermined height wherein each said vertically-swinging dog is moved to the nearly vertical position out of contact with the units and its return to a horizontal position is effected through a horizontally-disposed fluid pressure cylinder and piston unit fixed to the upwardly-extending frame members adjacent the dog which it moves with a piston rod operatively engaging the dog.

Claim 16

Apparatus as defined in claim 12 for arranging similar units into a vertical stack in which said vertically-swinging dogs and their respective cylinder and piston units are mounted on mounting members which are adjustable vertically and horizontally on their respectively vertically-extending frame members whereby the dogs may be adjusted to clear the tops of the units as they are carried by the conveyor to position over the elevator.

Claim 17

Apparatus as defined in claim 12 wherein said trip means on the frame below the elevator platform is vertically adjustable to adjust the vertical travel of the elevator relative to the height at which said dogs are positioned.

Claim 18

Apparatus as defined in claim 12 for arranging similar units into a vertical stack of predetermined height wherein there is a second vertically-movable stop means between the receiving end of the conveyor and the elevator movable between a raised position where it obstructs the travel of a unit into position over the elevator to a lowered position clear of the travel of th units, the fluid pressure cylinder for raising and lowering the stop, a fluid pressure valve between the stop and the elevator arranged to be operated by the travel of a unit between the stop and the elevator to actuate said fluid pressure cylinder to raise the stop, and a second trip means on the frame arranged to be engaged by said means below the elevator to actuate said fluid pressure cylinder to lower the stop means as the elevator reaches its lowermost position.

Claim 19

Apparatus for arranging units into vertical stacks of predetermined height comprising: a. a supporting frame with parallel sides and with a horizontally-extending conveyor means thereon, the conveyor means comprising two spaced parallel endless conveyors with means for continuously driving them in unison, the conveyor and frame having a receiving end onto which units to be stacked are placed and a delivery end opposite the receiving end, b. an elevator located intermediate the said two ends and positioned between the two endless conveyors, c. a first vertically-movable stop between the receiving end of the conveyor and the elevator for selectively controlling the movement of units by the conveyor means into position over the elevator, d. a second vertically-movable stop means adjacent the elevator for stopping each unit as it is moved by the conveyor means over the elevator, e. the frame having upwardly-extending guiding frame structures, one at each side thereof in transverse alignment with the elevator, each such upwardly-extending frame structure having a supporting plate thereon movable between a vertically-extending position where it is clear of any contact with the load at all and a horizontally-extending position where each projects under a unit which has been raised by the elevator to then be supported when the elevator descends, the plates at the two sides acting together to support the units of an incomplete stack as each unit is added, f. the elevator comprising a platform and a fluid-pressure cylinder and piston below the platform for raising and lowering it, the first and second stops each having its own fluid pressure-operated cylinder and piston for raising and lowering it, each of said plates having its own fluid pressure-operated cylinder and piston unit for operating it, and g. a first fluid pressure trip valve on the fRame below the elevator and fluid pressure circuit controlled thereby arranged to be tripped by the elevator as it reaches its lower limit of travel for lowering said first stop, a second fluid pressure trip valve between said first stop and the elevator and fluid pressure circuit controlled by it arranged to raise said first stop by supplying pressure to the cylinder and piston unit for that stop to effect the raising thereof when a unit moves past it toward the elevator; a third trip valve on said second stop arranged to be contacted and operated by a unit moving on said conveyor into position over the elevator and an associated fluid pressure circuit controlled thereby to effect operation of the elevator fluid pressure cylinder and piston to effect the raising of said elevator, a fourth trip valve on the frame under the elevator and associated fluid pressure circuits arranged to be operated by the upwardly-moving elevator to reverse the fluid pressure to the elevator operating cylinder and cause the elevator to lower, a fifth trip valve and associated fluid pressure circuit arranged to be operated by a stack of predetermined height for simultaneously supplying fluid pressure to the cylinders which operate the supporting plates to move them out of unit contacting position and at the same time supply fluid pressure to the cylinder and piston unit for lowering said second stop, and finally a sixth trip valve on the frame spaced toward the delivery end of the conveyor beyond the second stop and associated fluid pressure circuits for simultaneously operating the cylinder and piston units for the supporting plates in the reverse direction to restore them to unit-supporting position and at the same time effect the raising of said second stop.

Claim 20

Apparatus for arranging units into vertical stacks of predetermined height comprising: a. a supporting frame with parallel sides and with a horizontally-extending conveyor means thereon, the conveyor means comprising two spaced parallel endless conveyors with means for continuously driving them in unison, the conveyor and frame having a receiving end onto which units to be stacked are placed and a delivery end opposite the receiving end, b. an elevator located intermediate the said two ends and positioned between the two endless conveyors, c. a first vertically-movable stop between the receiving end of the conveyor and the elevator for selectively controlling the movement of units by the conveyor means into position over the elevator, d. a second vertically-movable stop means adjacent the elevator for stopping each unit as it is moved by the conveyor means over the elevator, e. the frame having upwardly-extending guiding frame structures, one at each side thereof in transverse alignment with the elevator, each such upwardly-extending frame structure having a supporting plate thereon movable between a vertically-extending position where it is clear of any contact with the load at all and a horizontally-extending position where each projects under a unit which has been raised by the elevator to then be supported when the elevator descends, the plates at the two sides acting together to support the units of an incomplete stack as each unit is added, f. the elevator comprising a platform and a fluid-pressure cylinder and piston below the platform for raising and lowering it, the first and second stops each having its own fluid pressure-operated cylinder and piston for raising and lowering it, each of said plates having its own fluid pressure-operated cylinder and piston unit for operating it, and g. a first fluid pressure trip valve on the fRame below the elevator and fluid pressure circuit controlled thereby arranged to be tripped by the elevator as it reaches its lower limit of travel for lowering said first stop, a second fluid pressure trip valve between said first stop and the elevator and fluid pressure circuit controlled by it arranged to raise said first stop by supplying pressure to the cylinder and piston unit for that stop to effect the raising thereof when a unit moves past it toward the elevator; a third trip valve on said second stop arranged to be contacted and operated by a unit moving on said conveyor into position over the elevator and an associated fluid pressure circuit controlled thereby to effect operation of the elevator fluid pressure cylinder and piston to effect the raising of said elevator, a fourth trip valve on the frame under the elevator and associated fluid pressure circuits arranged to be operated by the upwardly-moving elevator to reverse the fluid pressure to the elevator operating cylinder and cause the elevator to lower, a fifth trip valve and associated fluid pressure circuit arranged to be operated by a stack of predetermined height for simultaneously supplying fluid pressure to the cylinders which operate the supporting plates to move them out of unit contacting position and at the same time supply fluid pressure to the cylinder and piston unit for lowering said second stop, and finally a sixth trip valve on the frame spaced toward the delivery end of the conveyor beyond the second stop and associated fluid pressure circuits for simultaneously operating the cylinder and piston units for the supporting plates in the reverse direction to restore them to unit-supporting position and at the same time effect the raising of said second stop.