US3625505A

US3625505A - Machine for erecting cartons

Info

Publication number: US3625505A
Application number: US882097A
Authority: US
Inventors: Robert F Lense
Original assignee: Riegel Paper Corp
Current assignee: Riegel Paper Corp
Priority date: 1968-02-05
Filing date: 1969-12-04
Publication date: 1971-12-07
Anticipated expiration: 1988-12-07

Abstract

Flattened cartons are opened into erected positions by a setup and control unit as the cartons are drawn downwardly from a magazine into a transfer station by a transfer device. Thereafter, the cartons are shoved laterally out of the transfer station and onto a conveyor by a pusher and, as an incident to such shoving, are shifted into and latched in overcenter positions by the setup unit in order that complete control of the cartons may be maintained without danger of the cartons reassuming their flattened conditions during their transfer to the conveyor. A drive mechanism reciprocates the transfer device up and down between the transfer station and the magazine and operates with a differential action to cause the transfer device to dwell for a relatively long interval just below the cartons in the transfer station thereby to eliminate the need for precisely controlling the time of release of the cartons from the transfer device.

Description

United States Patent Inventor Robert F. Lense Rockford, Ill.

App]. No. 882,097

Filed Dec. 4, 1969 Patented Dec. 7, 1971 Assignee Riegel Paper Corporation Original application Feb. 5, 1968, Ser. No. 703,135, now Patent No. 3,504,596. Divided and this application Dec. 4, 1969, Ser. No. 882,097

MACHINE FOR ERECTING CARTONS 5 Claims, 13 Drawing Figs.

US. Cl. 271/14, 271/32 Int. Cl B65h 3/08, B65h 5/16 Field of Search 271/32, l4, 12

[56] References Cited UNITED STATES PATENTS 2,657,049 10/1953 Baker 271/14 2,922,646 1/1960 Buttner 271/14 X Primary Examiner-Joseph Wegbreit Attorney-Wolfe, Hubbard. Leydig, Voit & Osann, Ltd.

ABSTRACT: Flattened cartons are opened into erected positions by a setup and control unit as the cartons are drawn downwardly from a magazine into a transfer station by a transfer device. Thereafter. the cartons are shoved laterally out of the transfer station and onto a conveyor by a pusher and. as an incident to such shoving, are shifted into and latched in overcenter positions by the setup unit in order that complete control of the cartons may be maintained without danger of the cartons reassuming their flattened conditions during their transfer to the conveyor. A drive mechanism reciprocates the transfer device up and down between the transfer station and the magazine and operates with a differential action to cause the transfer device to dwell for a relatively long interval just below the cartons in the transfer station thereby to eliminate the need for precisely controlling the time of release of the cartons from the transfer device.

PATENTED UEC 7197i SHEET 1 0F 5 0M QTTORMEY/ PATENIED DEC 1 I97: 3525505 sum 2 BF 5 Hobart 1 MM cfh'rowozyf PATENTED DEC 7197! SHEET 5 OF 5 g gs mvzww'ow Robert" F1 .LQ/QSQ 44 WM, 4441 p 0 MACHINE FOR ERECTING CARTONS CROSS-REFERENCE TO A RELATED APPLICATION This application is a-division of U.S. application Ser. No. 703,] 35, filed Feb. 5, 1968, now US. Pat. No. 3,504,596.

BACKGROUND OF THE INVENTION This invention relates to amachine for erecting collapsed cartons while transferring the cartons to a conveyor from a stack in a magazine. Such cartons usually are rectangular when erected and comprise a sheet of paperboard folded and glued to form a first pair of opposing panels connected by a second pair of opposing panels, the panels being hingedly joined together along fold lines weakened as by scoring the paperboard. The cartons are stored in a flattened condition in the magazine and are removed one at a time from one end of the magazine by a transfer device which grips the exposed panel of the terminal carton in the stack and pulls the carton from the magazine into a transfer station. Thereafter, the cartons are shoved laterally out of the transfer station, usually by a pusher, and are delivered to the conveyor in substantially erected positions for filling with a product to be packaged.

SUMMARY OF THE INVENTION The primary aim of the present invention is to provide a new and improved transfer device which eliminates the need for precisely timing the release of the cartons from the transfer device in the transfer station and which draws the cartons into the transfer station with smoother motion and with greater repeatability than has been possible heretofore.

A further object is to achieve the foregoing with a transfer device which automatically dwells in the transfer station for a predetermined interval while the cartons are being shoved laterally from the transfer station.

The invention also resides in the comparatively simple and inexpensive construction of the transfer device and its ability to operate in a relatively trouble-free manner.

Other objects and advantageswill become apparent as the following description proceeds when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a flattened carton and of parts of the magazine of a new and improved carton-erecting machine embodying the advantageous features of the present invention.

FIG. 2 is a fragmentary front elevation of the machine.

FIG. 3 is an enlarged fragmentary cross section taken substantially along the line 3--3 of FIG. 2 and showing parts in moved positions.

FIG. 4 is a perspective view of an erected carton.

FIG. 5 is a fragmentary cross section taken substantially along the line 5-5 of FIG. 3.

FIG. 6 is a fragmentary sectional view taken in a vertical plane through the transfer station and showing the delivery of a carton from the magazine to the transfer station.

FIG. 7 is a view similar to FIG. 6 and showing the carton being shifted out of the transfer station.

FIG. 8 is a view similar to FIG. 7 and showing the canon being delivered to the conveyor.

FIG. 9 is an enlarged fragmentary cross section taken substantially along the line 99 of FIG. 2 and showing a novel drive mechanism for the transfer device.

FIGS. 10 and 11 are fragmentary perspective views illustrating successive positions of the transfer device and the drive mechanism during removal of a carton from the magazine.

- FIGS. 12 and 13 are diagrammatic illustrations of the prin' cipals of operation of the drive mechanism and the transfer device.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustration, the invention is embodied in a packaging machine (FIG. 2) in which cartons l0 stored in flattened condition in a magazine 11 are moved one at a time from the magazine and transferred to a continuously moving carrier or conveyor 12, the cartons being opened during this transfer to receive a product to be packaged. 0n the conveyor, the cartons pass through successive stations to be filled, glued, and closed in a manner well known to those of ordinary skill in the art.

Each of the cartons 10 shown herein comprises rectangular top and bottom panels 13 and 14 (See FIG. 4) hingedly connected along opposite side margins by two narrow

rectangular side panels

15 and 16. To close the open ends of the carton, top and bottom flaps l7 and 18 and side flaps I9 and 20 projecting outwardly at each end of the panels are folded across the open ends. Usually, such cartons are made of a single folded sheet of suitable material such as paperboard which is slit on opposite sides to form the flaps and is scored or otherwise weakened along the fold lines. The free ends of the sheet are glued together along a seam 21.

Preferably, the various mechanisms for opening, advancing, filling, and closing the cartons 10 are mounted on an elongated horizontal frame 22 (FIG. 2) and are operated in timed relation with each other by a single, continuously rotating horizontal cycle shaft 23 (FIG. 5) journaled on the frame and generally paralleling the path of the opened cartons. The conveyor 12 is in the form of a pair of endless chains disposed in parallel vertical planes and wound around two horizontally spaced pairs of sprocket wheels 24 (FIGS. 2 and 5) with the upper horizontal runs of the chains defining the path of the cartons. Spaced apart along and secured to the chains are a plurality of arms 25 arranged in pairs which project upwardly between two fixed carton-supporting rails 26 (FIGS. 3, 5 and 6) when on the horizontal runs to form the leading and trailing walls of a plurality of pockets along the conveyor, the distance between the adjacent pairs of arms being substantially equal to the width of the cartons. Thus, each carton is held in a pocket between the leading sides of one pair of arms and the trailing sides of the preceding pair so that the arms slide the cartons along the'rails and through the machine while holding them evenly spaced to position each of the cartons properly at the various operating stations.

Preparatory is being transferred to the conveyor 12, the cartons 10 are stored in a stack in the magazine 11 in flattened or collapsed condition, that is, with the top and bottom panels 13 and 14 lying side by side and offset laterally from each other by the width of one of the side panels and with the

side panels

15 and 16 lying flat against the top and bottom panels, respectively. In the present instance, the magazine 11 comprises an upright open frame including two bars 29 and 30 (FIGS. 1 and 2) of right-angle cross section opening inwardly and spaced apart to receive the corners of the stack on one side, the left side as viewed in FIGS. 1 and 2, and with an upwardly inclined plate 31 disposed on the opposite side of the stack with its inner surface bearing against the right-hand side of the stack. The bars and the plate are supported by a boxlike framework 33 connected to a standard 34 projecting upwardly from the frame 22 and are adjustable relative to one another to enable changing over of the magazine to accommodate cartons of different sizes. A positioning finger 35 fastened to the standard presses against the left-hand side of the stack to shift the lower cartons into engagement with the plate 31.

The cartons 10 are supported releasably in the magazine 11 by suitable means which herein comprise three fingers 36 and a rod 37 mounted at the lower end of the magazine and pro jecting a short distance in under the bottom canon in the stack. Two of the fingers are supported adjacent the front and rear side of the stack on the lower ends of upright rods 39 which are adjustable vertically on the framework 33 to permit changing of the elevation of the fingers. The remaining finger 36 is supported for vertical adjustment on the standard 34 along the left side of the stack, and the rod 37 is disposed at the lower edge of the inclined plate 31 along the right side of the stack. The cartons are pulled one by one from the stack through the open bottom of the magazine and bend upwardly a slight distance during removal (see FIG. 6) to pass around the supporting fingers 36 and the rod 37.

To effect the transfer of cartons 10 from the magazine 11 to the conveyor 12, a transfer mechanism includes a transfer device 40 for pulling the cartons in a downward path from the magazine into a transfer station 41 (FIGS. 1 and 7) together with a pusher 43 for thereafter shoving the cartons along a lateral path out of the transfer station and onto the conveyor. Herein, the transfer device 40 moves up and down beneath the magazine and toward and away from the bottom carton therein to engage the lower or exposed panel 14 of the bottom carton, grip the latter, and pull the carton past the fingers 36 and the rod 37 and into the transfer station 41 which is located below the magazine in horizontal alignment with the upper run of the conveyor.

More specifically, the transfer device 40 takes the form of four upwardly opening suction cups 44 carried on the upper ends of upright tubular rods 45 which are fastened at their lower ends to L-shaped arms 46 (FIGS. 2 and The latter, in turn, are connected to a single forwardly projecting arm 47 fastened to a reciprocating car 49 mounted for up and down sliding on a pair of vertical guides 50 anchored to the frame 22. As the car is reciprocated up and down on the guides, the suction cups 44 first are raised into engagement with the bottom of the stack (see FIG. 6) while suction is applied to the cups by a vacuum pump (not shown) through conduits 51 (FIG. 3) connected to the cups. The cups then are lowered to pull the gripped carton downwardly into the transfer station 41 and into a releasing position on the carton-supporting rails 26, such rails projecting upstream of the conveyor 12 and into the transfer station. When the carton is deposited on the rails, the suction is released from the cups to leave the carton resting in the transfer station. Application and release of the suction to the cups in timed relation with their up and down movement is governed by an electrically actuated valve (not shown) sequentially establishing and interrupting communication between the cups and the vacuum pump under the control of a limit switch 53 (FIG. 5) which is actuated by a cam 54 on the cycle shaft 23.

As shown in FIGS. 2 and 5, the pusher 43 herein comprises two transversely spaced blocks 55 which are shifted through a forward stroke toward the conveyor 12 each time a carton is delivered into the transfer station 41, the blocks first engaging the rear or left side of such carton and thereafter shoving the carton laterally out of the transfer station along the support rails 26. The blocks then are returned through a rearward stroke and are retracted out of the transfer station to clear the next carton drawn downwardly from the magazine 11 by the transfer device 40.

Each pusher block 55 is carried on a mounting arm 56 (FIG. 5) projecting forwardly from a transversely extending bar 57 which is fastened at one end to a car 59. The latter is mounted slidably on a pair of parallel guides 60 fastened to the frame 22 and is reciprocated back and forth along the guides to shift the pusher blocks through their forward and return strokes. To reciprocate the car, a pitman 61 is connected at one end to one side of the car is connected at its other end to a crank pin 63 which is eccentrically mounted on a drive wheel 64 so as to shift the car back and forth as the wheel is rotated. A shaft 65 joumaled in the frame is connected to rotate the wheel and is driven by the cycle shaft 23 through gearing 66 coupling the two shafts. Thus, successive cartons in the magazine 11 are drawn downwardly into the transfer station 41 by the transfer device 40 and then are shifted laterally by the pusher 43 along the support rails 26 to the conveyor 12 for filling and closing.

The flattened cartons 10 are erected automatically as an incident to being drawn from the magazine 11 into the transfer station 41, are shifted from erected to overcenter positions in the transfer station to prevent subsequent reflattening of the panels, and then are latched in the overcenter positions while being transferred to the conveyor 12 so that complete control over the cartons may be maintained at all times during such transfer. To these ends, a set up and control unit 67 is mounted in the transfer station and is disposed in both the downward and lateral paths of the cartons to cam the flattened cartons into erect positions as the cartons are drawn downwardly into the transfer station by the transfer device 40 and then to cam and hold the cartons in controlled overcenter conditions as the cartons are shoved laterally out of the transfer station by the pusher 43.

In the present instance, the set up unit 67 is located adjacent the right-hand of downstream side of the transfer station 41 and includes a pair of upright and transversely spaced legs 69 (FIGS. 1 and 2) depending from the framework 33 and fastened for vertical adjustment relative to the framework. Formed integrally with the lower end of each leg 69 is a shoe 70 (FIGS. 2 and 6) underlying the right-hand side of the cartons 10 and projecting into the downward path followed by the cartons as the latter are pulled from the magazine, the shoes being spaced transversely from one another a distance less than the length of the top and bottom panels 13 and 14 and being located beneath the lower panel of the bottom carton in the stack. The carton-supporting rod 37 of the magazine 11 spans the two shoes and is fastened near the junction of the shoes with the legs.

As shown most clearly in FIG. 6, the upper edge of each shoe 70 is inclined downwardly toward the transfer station 41 with a gradual slope and defines a cam surface 71 engageable with the front or leading side panel 15 of each carton 10 as the latter is drawn downwardly from the stack. Because of the sloping cam surfaces, the horizontal spacing between the angle bars 29 and 30 and the shoes gradually decreases in a downward direction, the spacing at the upper end portions of the surfaces being just greater than the flattened width of the cartons and the preferred spacing at the lower end portions of the surfaces being approximately equal to the erected width of the cartons. As a result, when the bottom panel 14 of each carton is gripped by the cups 44 and the carton moved downwardly, the inclined cam surfaces 71 engage the righthand carton edge and the side panel 15 to cam the top panel 13 to the left relative to the bottom panel 14 and thereby shift the carton toward its erected position. Such camming is continued until the carton is fully erected and is moved past the lower end portions of the cam surfaces and onto the supporting rails 26 as shown in FIG. 6. In this position, the angle between adjacent panels preferably is equal to although complete erection of the carton in the transfer station is not absolutely essential in that the carton could be delivered into the station in only a partially erected position with the angle between the panels being somewhat less than a right angle.

Upon reaching the transfer station 41, each carton 10 is held momentarily in its erected position to prevent the carton from collapsing and reassuming its original flattened position by folding from left to right about the weakened score lines joining the panels. For this purpose, the lower end of each shoe 70 is formed with a downwardly rounded toe 73 (FIG. 6) defining a positive stop which preferably is in the form of a shallow notch 74 located between the top and bottom of the toe. Each notch is spaced above the guide rails 26 and the bottom panel of a carton in the transfer station a distance equal to the erected height of the carton. Thus, the upper leading comer or edge of the carton between the

panels

13 and 15 lodges in the notches as an incident to the carton being placed on the rails thereby positively preventing the top panel 13 from shifting to the right relative to the bottom panel 14 and resisting the tendency of the carton to assume its originally flattened position.

In addition to camming and holding each carton 10 in an erect position in the transfer station 41, the shoes 71 coact with the pusher 43 to shift the carton into and latch the carton in an overcenter condition during transfer of the carton to the conveyor 12 so that flattening of the panels is prevented and control of the carton is maintained while such transfer is being effected. As shown in FIGS. 6 and 7, the pusher blocks 55 start through their forward stroke and engage the rear of trailing side panel 16 of the carton immediately after the latter has been placed on the support rails 26. During the initial engagement of the carton by the pusher blocks, the upper leading edge of the carton is pressed into the notches 74 to resist movement of the upper panel 13 while the lower panel 14 continues to be shifted by the pusher. The upper panel thus in effect is cammed rearwardly or to the left relative to the lower panel, and the carton is shifted overcenter past its erected position toward a reversely flattened position which is just opposite of the originally flattened position of the carton. To facilitate overcenter shifting of the carton, each pusher block 55 is formed with a forwardly opening mount defined by upper and lower jaws 75 and 76 (FIG. 7) spaced vertically from each other a distance just slightly greater than the erected height of the carton. During the forward stroke of the pusher blocks, each lower jaw 76 slips under the carton until the lower rear carton edge engages an abutment formed by a comer 77 located at the intersection of the upper surface of the lower jaw with a sloping rear surface 79 defining the rear of the mouth and inclined downwardly from the upper jaw. Thereafter, the lower panel of the carton is shoved forwardly by the corners 77 while the upper panel is held stationary by virtue of the upper forward carton edge being located in the notches 74 thereby causing overcenter shifting of the carton during the forward stroke of the pusher blocks. The upper jaws 75 overhang the upper panel 13 and prevent the carton from rising upwardly off of the lower jaws as the panels are shifted relative to each other. Preferably, the lower surfaces of the upper jaws are inclined downwardly and rearwardly as indicated at 80 in FIG. 7 in order to hold the upper panel continuously as the height of the carton is decreased by the overcenter shifting.

After the carton 10 has been shifted overcenter approximately 30 from its erect position, the rear panel 16 seats flush against the inclined surfaces 79 between the jaws 75 and 76, and the upper rear edge of the carton moves into engagement with an abutment formed by the corner 81 between the inclined surface 79 and the lower surface 80 of each upper jaw. At the same time, the effective height of the carton or the distance between the panels 13 and 14 is reduced sufficiently to allow the upper forward carton edge to move downwardly from the notches 74 and to slip beneath the bottoms of the toes 73 on the shoes 70. Upon slipping beneath the toes 73, the carton is free to slide along the support rails 26 as the pusher 43 continues its forward stroke. The vertical spacing x (FIG. 7) between the supporting rails and the lower surface 83 of each toe is less than the full erected height of the carton and thus the top and bottom panels 13 and 14 are squeezed together between the toes and the support rails. As a result, the carton is shoved out of the transfer station 41 while being latched in its overcenter condition by the toes, the rails and the pusher. Complete control of the carton thus is maintained during the transfer since the natural stiffness of the paperboard prevents the carton from flattening reversely from its overcenter position and since the toes resist the natural tendency of the carton to return to its erected position and then flatten forwardly.

As shown in FIGS. 7 and 8, the carton slides beneath the shoes 70 and along the support rails 26 until it is picked up by one pair of trailing arms 25 of the conveyor 12. The arms engage the trailing edge of the carton just as the carton recedes from beneath the toes 73 and just as the arms turn around the upper conveyor sprocket 24. Thus, the carton is pushed along the rails by the trailing arms and, when the latter move onto the upper horizontal run of the conveyor, the spacing between successive pairs of arms becomes equal to the width of the carton to hold the same in a fully erected position (see FIG. 2) during packaging of the product. Preferably, the lower surface or sole 84 of each shoe 70 is gradually inclined upwardly and forwardly from the toe to a height greater than the erected height of the carton in order to establish clearance allowing the carton to start returning to its erected position just an instant before being picked up by the conveyor arms.

In accordance with the primary aspect of the invention, the transfer device 40 is shifted up and down between the transfer station 41 and the magazine 11 by a new and improved drive mechanism (FIG. 9) which causes the transfer device to dwell for a relatively long interval at the end of its downward stroke with the suction cups 44 disposed substantially at the level of the bottom of the carton 10 in the transfer station so that the carton may be placed positively on the support rails 26 without need of precisely timing the release of the suction from the cups. The drive mechanism preferably operates with a differential action to effect the dwell in the motion of the cups while drawing the cartons into the transfer station with greater repeatability and smoother motion than otherwise would be the case if the transfer device were shifted with a cam and spring arrangement.

Basically, the drive mechanism 85 is a form of a planetary differential having two input elements 86 and 87 (FIG. 9) driving an output element 89 which is connected to the suction cups 44, the output element and the cups being moved in accordance with the resultant motion of the two input elements. The input element 86 comprises a rotatable crank coupled to the output element 89 which herein is a pitman connected to the car 49 to shift the latter up and down along the guides 50 and move the suction cups 44 between the transfer station 41 and the magazine 11 in response to rotation of the crank and in timed relation with the reciprocation of the pusher 43 into and out of the transfer station. The harmonic or sinusoidal motion normally produced by the crank is modified, however, by the input element 87 in such a manner that the cups dwell or substantially dwell at the end of their downward stroke for a considerably longer interval than would occur with pure harmonic motion, the interval being sufficiently long to delay the upward return of the cups until the pusher has shoved the newly erected carton out of the transfer station and out of the path of the cups. With the dwell period of the cups lengthened, the cups do not have to travel downwardly a considerable distance below the carton to gain the necessary time for the carton to be shoved out of the transfer station and, as a result, the cups can be stopped in a release position (see FIG. 7) substantially level with the bottom of the carton and the upper surfaces of the support rails 26 and with little or no downward overtravel. Since the cups dwell for a relatively long period of time adjacent the support rails, the suction can be held on the cups until after the carton has been drawn onto the rails by the cups and does not have to be released at a precisely accurate time as would be required to permit the cups to travel below the rails. Accordingly, with the present arrangement, the carton may be placed positively on the rails by the cups to insure against uncontrolled free flight of the carton and yet extremely precise control of the time of the release of the suction is unnecessary to effect such placement.

More specifically, the pitman 89 extends generally vertically beneath the car 49 with its upper end connected pivotally to a pin 90 (FIG. 3) projecting outwardly from one side of the car and with its lower end connecting to the crank 86 by a rotatable shaft 91 (FIG. 9) which is journaled intermediate its ends by a bearing 92 located in one end portion of the crank. A key 93 fastens the crank for rotation with a horizontal drive shaft 94 which is journaled to turn about its own axis a by a housing 95 depending from the main frame 22. Power for rotating the crank 86 is transmitted to the shaft 94 from the pusher drive shaft 65 by a chain 96 (FIGS. 2 and 5) which is trained around

sprockets

97 and 99 fast on the shaft 65 and on a shaft 94a connected to the shaft 94. An idler sprocket 100 (FIG. 5) pivoted on the frame engages the chain to keep the latter in a tight condition.

Accordingly, the shaft 94 is rotated in synchronism with the shaft 65 and rotates the crank 86 which acts through the pitman 89 to reciprocate the car 49 up and down on the guides 50 and thereby move the suction cups 44 toward and away from the magazine 11. The movement of the cups thus occurs in timed relation with respect to the back and forth reciprocation of the pusher 43, the cups in this instance moving upwardly just after the pusher has shoved a carton laterally from the transfer station 41 and moving downwardly to place a succeeding carton in the transfer station before the next forward stroke of the pusher.

In carrying out the present invention, the harmonic motion which normally would be undertaken by the upper end of the pitman 89 as a result of being driven by the crank 86 is modified in order to cause the suction cups 44 to dwell for a relative long interval at the end of their downstroke, such modification of the motion being effected by the second input element 87 of the drive mechanism 85. For this purpose, the second input element 87 comprises a second crank in the form of a rotatable eccentric connected to the pitman and operable to cancel out the motion transmitted to the pitman by the crank during the time and latter approaches, crosses and leaves its bottom dead center position. As shown most clearly in FIGS. 9 and 10, the eccentric 87 is simply a circular disc which is joumaled rotatably by a bushing 101 within a round opening formed in a collar 103 to which the lower end of the pitman is fastened. The eccentric is mounted on one end portion of the shaft 91 and is coupled for rotation with the shaft by a radial drive pin 104, the axis b of the shaft 91 being offset radially from the geometric axis or true center c of the eccentric. Movement of the pitman axially of the eccentric is prevented by retaining plates 105 loosely abutting the sides of the collar and fastened to the sides of the eccentric by screws 106 which are aligned horizontally with the center c of the eccentric.

To rotate the eccentric 87, a planet gear 107 (FIGS. 9 and 10) is carried on the opposite end portion of the shaft 91 and is coupled to turn the latter through a radial drive pin 109. The planet gear meshes with a one to one ratio with a stationary sun gear 110 loosely telescoped over and rotatable on the shaft 94 and anchored to the housing 95 by screws lll extending through the sun gear and threaded into the housing. As the crank 86 is rotated, the planet gear walks around the sun gear about the axis a of the shaft 94 and, at the same time revolves about its own axis b to cause turning of the shaft 91 and the eccentric through one full revolution for each one-half revolution of the crank.

As shown in FIGS. 9 and 10 and diagrammatically in FIG. 12, the eccentric 87 is positioned at top dead center within the collar 103 at the same time the crank 86 is positioned at its top dead center. At this time, the suction cups 44 are at the uppermost point in their stroke and are in engagement with the lower carton 10 in the magazine 11. As the crank is rotated clockwise by the shaft 94 from the position shown in FIG. 10 to that shown in FIG. 11, the cups start moving downwardly and draw the carton toward the transfer station 41. In turning through each one-fourth revolution, the crank 86, acting alone and without the eccentric, would cause shifting the suction cups through a stoke d (FIG. 9) equal in length to the distance between the axes a and b of the

shafts

94 and 91. During the first one-fourth revolution of the crank from top dead center, however, the eccentric 87 is turned clockwise through one-half revolution from top dead center to bottom dead center as a result of the planet gear 107 rolling around the sun gear 110 about the axis a and revolving about its own axis b. The eccentric itself thus acts to move the cups downwardly through a stroke equal in length to twice the distance e between the axis b and the center c of the eccentric. Accordingly, the motions of the crank and the eccentric are added or combined during the first one-fourth revolution of the crank thereby shifting the cups downwardly through a longer stroke f (equal in length to the distances d+2e) and with greater velocity than would result from the crank acting alone with pure harmonic motion. The motions undertaken by the driving elements during rotation of the crank are illustrated diagrammatically in FIG. 12 with the curve h indicating the path following by the center c of the eccentric. The curve k (FIG. 13) indicates the path actually followed by the suction cups 44, and the curve k represents the path which the cups would follow if reciprocated by the crank alone and without the differential action produced by the eccentric.

As soon as the crank 86 has rotated through its first onefourth revolution, the eccentric 87 reaches its bottom dead center. Then, as the crank turns through another one-fourth revolution and approaches its bottom dead center position (See FIG. 12), the eccentric turns through one-half revolution from its bottom dead center toward its top dead center. In so turning, the eccentric tends to shift the suction cups 44 upwardly through a stroke of length 2e (FIG. 9) thereby subtracting from the downward motion producted by the crank and causing a resultant downward displacement of the cups through a relatively short stroke g (FIG. 12) equal to the distance d-2e as the crank moves through its second onefourth revolution. Thus, the cups move downwardly at a slower velocity as they approach the support rails 26.

Upon passing bottom dead center and completing one-half revolution, the crank 86 starts shifiing the cups 44 upwardly. The eccentric 87, however, again starts turning from its top dead center toward its bottom dead center and tends to shift the cups downwardly thereby again subtracting from the motion of the crank and retarding the upward motion of the cups during the third one-fourth revolution of the crank. As the crank starts through its final one-fourth revolution, the eccentric once again turns from its bottom dead center toward its top dead center to add to the upward motion produced by the cups and to cause the major portionof the upstroke of the cups to occur during the final one-fourth revolution of the crank.

Because the eccentric 87 subtracts from the motion of the crank 86 as the latter approaches, crosses and leaves its bottom dead center position, very little motion is transmitted to the cups 44 as the cups complete their downstroke and begin their upstroke. As shown in FIGS. 12 and 13, the cups and the center c of the eccentric move along substantially flat paths m and n, respectively, the crank turns through its lowermost angle y of about 75. As the crank turns through this angle, the cups are displaced only about 0.010 of an inch in each direction. Thus, the cups, for all practical purposes, dwell just beneath the upper surfaces of the rails 26 from the time a carton 10 is placed on the rails until after the carton is shoved out of the transfer station by the pusher 43, the upper surfaces of the cups moving below the upper surfaces of rails a maximum distance of only about one thirty-second of an inch. Accordingly, the suction need not be released from the cups at the exact instant the carton is deposited on the rails, but instead, may be held until shortly after the carton is set in place.

From the foregoing, it will be apparent that the drive mechanism allows a wider latitude in the timing of the release of the suction from the cups 44 and yet insures that the cartons 10 will not fall on the rails 26 in free flight or will not be damaged by the rails as a result of the cups pulling downwardly on the cartons after the latter reach the rails. The differential action of the drive mechanism produces relatively jerk-free motion of the cartons and this, together with the build-in dwell, enhances the repeatability of the machine and results in trouble-free operation. In addition, the drive mechanism is constructed in large from standard commercially available elements thus making the cost of the mechanism comparatively low.

I claim as my invention:

1. In a machine for handling collapsible cartons, the combination of, a frame, a magazine having an open end and mounted on said frame for releasably holding a stack of flattened cartons, a transfer device supported on said frame, mechanism for moving said transfer device toward said magazine to engage one exposed side of the terminal carton and for moving said transfer device away from said magazine to deliver the carton from the magazine into a transfer station, said transfer device releasing said carton in said transfer station and substantially stopping in a release position adjacent said one side of said carton, means for shifting the carton out of said transfer station, said mechanism including means for causing said transfer device to dwell in said release position without any substantial movement from the time said carton is delivered into said transfer station until after the carton is shifted out of the transfer station, said mechanism and said last-mentioned means comprising a power-rotated shaft, a first crank connected to and rotatable with said shaft and movable from a first dead center position to a second and opposite dead center position as the shaft is turned through one-half revolution, a second crank rotatable both with and on said first crank and movable from a first dead center position to a second and opposite dead center position, a pitman connecting said cranks to said transfer device to reciprocate the latter toward and away from said magazine with each of said cranks being in corresponding first dead center positions when said transfer device is in engagement with a carton in the magazine, and gearing responsive to rotation of said shaft and connected to turn said second crank through one revolution for each one-half revolution of said first crank whereby said second crank is disposed in its first dead center position when said first crank is turned to its second dead center position.

2. A machine as defined in claim 1 further including a second shaft journaled by the free end portion of said first crank and paralleling said first shaft, said second crank being rotatable with said second shaft, and said gearing comprising a stationary sun gear rotatable relative to said first shaft, and a planet gear coupled for rotation with said second shaft and meshing with and orbiting said sun gear to revolve said second crank in response to rotation of said first crank.

3. A machine as defined in claim 2 in which said second crank comprises a circular disc eccentrically mounted on and rotatable with said second shaft and engageable with said pitman.

4. In a machine for handling collapsible cartons, the combination of, a frame, a generally upright magazine mounted on said frame for releasably holding a stack of flattened cartons, a transfer device movably supported on said frame, mechanism for moving said transfer device toward said magazine to engage one exposed side of the terminal carton therein and for moving said transfer device downwardly away from the magazine to a transfer station disposed below said magazine, said transfer device releasing said carton in said transfer station, means for moving the released carton out of the transfer station, said mechanism including means for causing said transfer device to dwell at a substantially fixed elevation from the time the carton is released from the transfer device until after the carton is moved out of the transfer station, said mechanism and said last mentioned means including a differential having two driven input elements and having an output element driven in accordance with the resultant motion of said input elements and connected to said transfer device, one of said input elements being connected to said output element to move the transfer device toward and away from said magazine, and the other of said input elements being connected to said output element to subtract from the motion normally imparted to the transfer device by said one input element from the time the transfer device reaches said transfer station until after said carton has been moved out of said transfer station.

5. A machine as defined in claim 4 in which said one input element comprises a power-rotated crank and said output element comprises a pitman connecting said crank to said transfer device to reciprocate the latter toward and away from said magazine in response to rotation of the crank, said other output element comprising a second crank mounted both for rotation with said one crank and for rotation on said one crank and connected through said pitman to reciprocate said transfer device, and means for turning said second crank through two full revolutions for each full revolution of said one crank.

Claims

1. In a machine for handling collapsible cartons, the combination of, a frame, a magazine having an open end and mounted on said frame for releasably holding a stack of flattened cartons, a transfer device supported on said frame, mechanism for moving said transfer device toward said magazine to engage one exposed side of the terminal carton and for moving said transfer device away from said magazine to deliver the carton from the magazine into a transfer station, said transfer device releasing said carton in said transfer station and substantially stopping in a release position adjacent said one side of said carton, means for shifting the carton out of said transfer station, said mechanism including means for causing said transfer device to dwell in said release position without any substantial movement from the time said carton is delivered into said transfer station until after the carton is shifted out of the transfer station, said mechanism and said last-mentioned means comprising a powerrotated shaft, a first crank connected to and rotatable with said shaft and movabLe from a first dead center position to a second and opposite dead center position as the shaft is turned through one-half revolution, a second crank rotatable both with and on said first crank and movable from a first dead center position to a second and opposite dead center position, a pitman connecting said cranks to said transfer device to reciprocate the latter toward and away from said magazine with each of said cranks being in corresponding first dead center positions when said transfer device is in engagement with a carton in the magazine, and gearing responsive to rotation of said shaft and connected to turn said second crank through one revolution for each one-half revolution of said first crank whereby said second crank is disposed in its first dead center position when said first crank is turned to its second dead center position.