Apparatus for automatically stacking material

Claim 2

In a machine for stacking identically sized sheet-like articles fed thereto seriatim by a continuous conveyor and formed to define a magazine for receiving said articles from said conveyor, a reciprocative elevator defining the bottom surface of said magazine and movable between an upper normal article receiving position and a lower article stack discharging position, stack separator means extendable across said magazine in a plane above that of the normal position of said elevator for supporting infeeding articles when in the extended condition, article sensor means including a photoelectric cell disposed to detect a stack upon its building up to a predetermined elevation within said magazine and including a finger yieldingly bearing on the topmost article of the stack, means including a fluid motor controlled by said sensor means for progressively lowering said elevator at a velocity dependent upon the response time of said photoelectric cell and said motor when a stack has reached said predetermined elevation so as to accommodate additional infeeding articles on said stack, means for counting the number of said articles feeding to said magazine and settable to generate a signal upon attainment of a predetermined count, means activated by said signal generated by said counting means for extending said separator means, and means activated by the extension of said separator means for lowering said elevator continuously to its lowermost stack discharge position.

Claim 3

The invention according to claim 1, including stack height detector means adjustably mounted to generate a signal upon the progressive lowering of said elevator a predetermined distance below the plane of said separator means when extended, and wherein the means for extending said separator means are activated by said signal generated by said detector means.

Claim 4

The invention according to claim 2, wherein the means for extending said separator means are activated either by said signal generated by said counting means or said signal generated by said detector means.

Claim 5

The invention according to claim 1, wherein said separator means when extended across said magazine move in the direction running from the trailing edge to the leading edge of the articles fed into said magazine.

Claim 6

The invention according to claim 1, including means for retarding the velocity of the progressive lowering movement of said elevator below the velocity of its continuous movement to the stack discharge position.

Claim 7

The invention according to claim 5, including means for disabling said retarding means while a stack extends above the predetermined elevation detected by said sensor means.

Claim 8

The invention according to claim 6, wherein said disabling means remains effective until the top of said stack reaches said predetermined elevation detected by said sensor means.

Claim 9

The invention according to claim 1, wherein said means for extending said separator means operates, when activated, to render said article sensor means ineffective.

Claim 10

The invention according to claim 1, wherein said means extending said separator means operates, when deactivated, to render said article sensor means effective.

Claim 11

In an apparatus for stacking sheet-like cartons conveyed thereto seriatim including a magazine for receiving said cartons, a carton-supporting elevator in said magazine vertically movable between a normal uppermost carton receiving position and a lowermost carton discharge position, a knife-like separator normally retracted in a position outside said magazine and extendable laterally across said magazine in a plane above that of said elevator when in its normal position to intercept and support cartons entering said magazine, motoR means for operating said elevator, motor means for operating said separator, carton sensor means including a sensing finger for determining when a pile of cartons has built up to a predetermined elevation within said magazine, and presettable means for selecting a characteristic of the stack to be formed, a circuit for controlling the operation of said elevator and said separator including an electric power source, contacts connected to said source and operated by said separator when fully extended, contacts connected to said source and operated by said elevator when in its normal uppermost position, contacts connected to said source and comprising said presettable means for conducting a signal upon attainment of the selected stack characteristic, a photoelectric cell associated with said carton sensor means and when activated emitting output signals to said elevator motor for lowering said elevator progressively to maintain the carton stack top level at substantially the same elevation, a switching device normally emitting an output for activating said photoelectric cell, said device being responsive to concurrent inputs through said contacts operated by said elevator and the contacts comprising said presettable means to switch its output from a circuit to said photoelectric cell to a circuit for energizing the motor means operable to extend said separator, and contacts connected to said source and operated by said separator when fully extended to complete a circuit independent of said photoelectric cell for energizing the motor means operable to lower said elevator for continuously lowering said elevator to its lowermost discharge position.

Claim 12

In an apparatus for stacking sheet-like cartons conveyed thereto seriatim including a magazine for receiving said cartons, a carton-supporting elevator in said magazine vertically movable between a normal uppermost carton receiving position and a lowermost carton discharge position, a knife-like separator normally retracted in a position outside said magazine and extendable laterally across said magazine in a plane above that of said elevator when in its normal position to intercept and support cartons entering said magazine, motoR means for operating said elevator, motor means for operating said separator, carton sensor means including a sensing finger for determining when a pile of cartons has built up to a predetermined elevation within said magazine, and presettable means for selecting a characteristic of the stack to be formed, a circuit for controlling the operation of said elevator and said separator including an electric power source, contacts connected to said source and operated by said separator when fully extended, contacts connected to said source and operated by said elevator when in its normal uppermost position, contacts connected to said source and comprising said presettable means for conducting a signal upon attainment of the selected stack characteristic, a photoelectric cell associated with said carton sensor means and when activated emitting output signals to said elevator motor for lowering said elevator progressively to maintain the carton stack top level at substantially the same elevation, a switching device normally emitting an output for activating said photoelectric cell, said device being responsive to concurrent inputs through said contacts operated by said elevator and the contacts comprising said presettable means to switch its output from a circuit to said photoelectric cell to a circuit for energizing the motor means operable to extend said separator, and contacts connected to said source and operated by said separator when fully extended to complete a circuit independent of said photoelectric cell for energizing the motor means operable to lower said elevator for continuously lowering said elevator to its lowermost discharge position.

Claim 13

The invention according to claim 10, wherein said presettable means comprises a cyclomometer disposed to count cartons being conveyed to said magazine and operating its associated contacts upon reaching a selected count.

Claim 14

The invention according to claim 10, wherein the contacts comprising said presettable means are adjustably mounted for operation by said elevator upon lowering to a selected elevation below said separator so as to form a carton stack of selected height.

Claim 15

The invention according to claim 10, wherein the contacts comprising said presettable means includes a first pair of contacts operated by a cyclomometer disposed to count the cartons feeding to said magazine and actuate said first pair of contacts upon attaining a selected count, and a second pair of contacts adjustably mounted for actuation by said elevator upon lowering to a selected elevation, said first and second pair of contacts being connected in parallel in an input line to said switching device so as to conduct alternatively one of the two concurrent inputs for causing said device to switch its output to energize the motor means operable to extend said separator.

Claim 16

The invention according to claim 10, including contact means operated by the normal output of said switching device for retarding the operation of the motor means operable for lowering said elevator during its progressive lowering movement.

Claim 17

The invention according to claim 14, wherein said retarding means includes parallel load circuits for energizing the motor means operable for lowering said elevator, one of said circuits including a pair of normal closed magnetically actuated contacts, the other of said parallel circuits including a normal open pair of magnetically actuated contacts in series with a resistor, and a magnetic coil for operating both said pairs of contacts and energized by said normal output of said switching device to complete only the parallel circuit which includes said resistor.

Claim 18

The invention according to claim 15, including means for delaying the operation of said retarding means, said delaying means including contacts operated by said elevator when in its normal uppermost position.

Claim 19

The invention according to claim 16, including means for delaying the operation of said retarding means until said elevator has lowered the top of a stAck to said predetermined elevation, said delaying means including a holding circuit in parallel with the circuit for energizing said elevator motor means, said holding circuit being established through contacts operated by said elevator when in its uppermost normal position and maintained after opening of said contacts resulting from progressive lowering of said elevator by another pair of self-holding magnetic contacts operated by a magnetic coil in said parallel holding circuit.

Claim 20

The invention according to claim 10, wherein said apparatus includes a pusher projectable for discharging a stack of cartons from said elevator and a motor for operating said pusher, and wherein said circuit includes contacts operated by said elevator upon descending to its lowermost discharge position for completing a circuit energizing said pusher operating motor.

Claim 21

The invention according to claim 10, including a fluid circuit, wherein said motors operate in response to pressurized fluid and are coupled to said fluid circuit through valve means under the control of electromagnetic actuators, and wherein said motors are energized by completing a load circuit through said actuators.

Claim 22

The invention according to claim 19, wherein said control circuit includes switching means settable to complete individual load circuits through said electromagnetic actuators under control of a manually operable contact within each said load circuit.