US2609736A - Machine for folding paper box blanks on a stack thereof - Google Patents

Description

Sept. 9, 1952 H. E. MONTGOMERY MACHINE FOR FOLDING PAPER BOX BLANKS ON A STACK THEREOF 5 Sheets-Sheet l Filed June 3, 1948 H. E. MONTGOMERY Sept. 9,4 1952 MACHINE FOR FOLDING PAPER BOX BLANKS ON A STACK THEREOF' Filed June 5, 1948 3 Sheets-Sheet 2 Sept. 9, 1952 i H. E. MONTGMERY MACHINEfFOR FOLDING PAPER BOX BLANKS ON A STCK THEREOF 5 Sheets-Sheet 3 Filed June 3, 1948 Patented Sept. 9, 1952 UNITED i-STATES PAT ENTOFICE t MACHINE FOR FOLDING PAPER BOX BLANKS ON A STACK THEREOF` Hugh E. Montgomery, Jacksonville,

ApplicationJune 3, 1948, Serial No. 30,847

`1 This inventionrelates to a machine for folding the topmost paper box blank of a stack of blanks before removing the blank from the stack. Folding machines which have heretofore been made have withdrawn the blanks, one by one, from the top or bottom of a stack to a folding station where the end portions of the blank are folded over the central portion,` the overlapping or abutting 'extremities of the folded portionsV being thereafter joined by adhesive tape, metal staples, or othermeans. A i

According to the present invention, a machine is provided which holds a stack of blanks and operates on the topmost blank while it is still in the stack to fold'its end portions or aps over the mid-portion. The folded blank is then removed from the stack and transferred to a stitcher or to a tape-applying mechanism. The mechanism hereinafter described and claimed operates to apply suction cups to the flaps or end portions of the topmost blank of the stack and to Yrock these flaps upward, While the center portion is held down, so as to permit the introduction of suitable folding arms under the raised flaps to complete the folding operation.

A more complete understanding of the invention may be had 'from the following description thereof and from the drawings, of which- Figure 1 is a front elevational view of a machine embodying the invention;

Figure 2 is a partial side elevation of the same;

Figure 3 is a fragmentary elevational view of a suction cup and the linkage for actuating one of the folding arms;

Figure 4` is a similar view, showing the parts in different positions of operation;

Figure 5 is a partial plan view of the machine;

Figure 6 is a fragmentary sectional view, on the line B--B in'Figure 2, the partsjshown being in a different position of operation;

Figure 7 is a section on the line 1--1 of Figure 6;

Figure 8 is a section on the line 8-8 of Figure 6; and

Figure 9 is aperspective View of a typical blank to be folded. j

The machine is provided with a magazine holding a stack of blanks to be folded, and this magazine may be supported on a base 20 from which rise a wall 2| and suitable uprights 22. These uprights support mechanism for elevating the stack of blanks gradually so that as the topmost blanks are folded and removed, one by one, the level of the top of the stack is maintained substantially constant. Any suitable apparatus 6 Claims. (Cl. 233-49) may be employed for elevating the stack during the operation of the machine. As shown, the blanks are stacked on agplatform 24 which is provided with extensions 26 interiorly screwthreaded for threaded engagement with vertical screws 28. The latter are rotated slowly during the operation of the machine so as to elevate the platform 24 and the stack of blanks supported thereon, the rate of rotation being adjusted in accordance with the individual thickness of the blanks in the stack.

The folding operation is performedon the topmost blank while it is still `on the stack. This operationcomprises essentially two steps, namely, a preliminary vlifting of the end portions or flaps of the topmost blank, and, second, the completion of the folding operation by another instrumentality. During the folding operation, the central portion of the blank is held down by ,suitable horizontal strips 3l) which are supported by suitable members 32 from a longitudinal beam 34 at the top of the main frame.

A typical blank is shown in Figure 9, this blank having end portions or flaps 36 which are folded toward each other over the mid-portion of the blank until their end edges abut or overlap each other.

The initial lifting of the flaps of the topmost blank is done by lifting mechanisms, including suction cups 40 which are located over the end flaps of the blank, preferably near the extreme end thereof. The suction cups 40 and their sup-i porting and operating apparatus are symmetrical in arrangement and movement so that a description of one supporting means will suffice for both. Referring to the lifting mechanism shown at the left in Figure 1, the cup 4U is mounted at the lower end of a vertical member 42 which is hollow and communicates at its upper end with a flexible tube 44 leading to a suction pump (not shown). The member 42 is integral with a horizontal hub member 46 in which is a short shaft or pin 48. From the hub member 46 rises a vertical extension 50 which is pivotally connected, as at 52, to a horizontal link 54, the other end of which is pivoted, as at 56, to a crank 58 mounted on a shaft B0. Rockable on the shaft 48 is a hub member 62 of a link 64 which extends down to a bearing B6at the lower end of a vertical frame member 68 secured to a transverse frame member 69.

` The bearing 66 is preferably located so that its rocking axis is near the line of bend of the flap of the blank which is to be folded. The hub 62 is made hollow around the shaft 48 for a portion of its length so as to provide clearance for a spring which s coiled about the shaft 48 and engages the hub 62 and also the hub 46. The spring is tensioned in such a manner as to impress on the hub 46 and the members 42 and 50 which are integral therewith, a counterclockwise torque. A stop pin 12 is mounted on the vertical member 42 and is arranged to engage the link 64 to maintain the member 42 in a vertical Vposition when the mechanism is in the position shown in full lines in Figure 1.

When the crank 58 is revolved, the link 54 pulls the members 50 and 42 toward the right, tending to rock these members about the shaft 46. Since such rocking movement is opposed bythe spring l0, the members 50 and 42 and the link 64 rock as a unit about the axis of thebearing 66 totheY position shown atA in dotted lines in Figure 1. Since the aXis of the bearing 66 is near the fold line of the ap, the cup 40 follows an arcuate path substantially identical with that of the portion of the flap which ittouches. When the cup frame reaches the position A, ,the hubs 46 and 62 `bring up against a stopv 74 whereupon further movement of the link 54 to the right rocks the members e2 and 50 about the axis of the shaft '43 so as to swing the suction cup 40 rapidly outward to the positionv indicated in dotted lines at Bv in Figure 1, the cup 40 then being clear' of the flap which is being folded. Immediately prior to the outward movement of the Ycup 40 from its normal position onl the upper surface of. the nap, suction is applied through the hose 44 so as to cause the flaptocling to the cup. When the cup is elevated to` position A, the flap is brought up with it. The underlying flap of. the nextfblank Yis prevented f -romcoming up with the top of the topmost blankby suitable retarding means, such as a brush 80 supported with its bristles bearing against the endedges of the uppermost blanks.

When the cup,` 40' reaches. the position A, a horizontal arm 82 movesy into the wedge-shaped space between the flap of the uppermost blank and the underlying flap of the next blank so as to engage the'und'er surface of the uppermost flap, whereupon the suction is released so that the cupdil is free to move away from the flap to position B. The arm 82, as indicated in Figure e, continuesV its inward motion in an approximately horizontal. path for about two-thirds of the distance between the endof the flap and the line of fold. The arm thereupon moves through a substantially semi-circular path pushing the lapahead ofit until the flap is folded to the position shown in Figure 4. The arm 82 thereupon moves outward to the position indicated ata and is then ready for the next folding operation. Y The suction cup i and the arm 82 at the right hand portion of the machine, as shownin Figure 1,

move through paths symmetrical with those ofV the left-hand cup and arm, hereinbefore described, and simultaneously therewith.

When the folding arms 8:2 are reachingA the position shownin- Figure e, completing the folding operation, alpusher 86 is actuated to pushthe blanktowardthe rear so that it passes between two successive pairs of narrow rolls twhichare deeplyA grooved circumferentially, the rolls of each pair being so spaced apart that thefolded edgesof. thefblank engage. in the grooves off-the rolls; VThis maintains the blank in its folded condition whileit is vpassing from Athe folding arms 82 either to conveyor belts ..90 byy which a` gummed tape 92 is appliedtojoin the ends of the folded flaps, or-to a. stitching mechanism (notshown). If desire'daninclined guide mem-V 4 ber 94 may be mounted adjacent to the upper conveyor belt 96, as indicated in Figure 1, to be engaged by the leading edges ofthe folded flaps as the blank approaches the conveyor.

The suction cups 40, the folding arms 82, and the pusher 85 are operated in suitably timed relation by any suitable driving apparatus. As shown by way of example, a prime mover, such as an electric motor |00, is mounted on the main frame and is connected by a chain |02 to a sprocket |04 mounted on a shaft |06. The shaft |05 is connected by gear wheels |01 and |08 to a parallel shaft |09 which carries two worms ||0. Each of these worms is in mesh with a suitable worm gear on a short shaft ||2. On the same shaft with the worm gear is a gear wheel I I3 which meshes with gear wheels ||4 and H6 of different sizes so that the gear wheel H4 revolves once for each two revolutions of the gear wheel H6. Mounted to revolve with the gear wheel ||4 is a crank ||8, a crank |20 being mounted to revolve' with the gear wheel ||6.

The folding arm. 82 is connectedto and supported by the respective cranks ||8 and |20 by means of links |22 and |24. The result of this linkage and the movements of Vthe cranks H8 and |20 is to impart to the folding arm 82 a Figure 8 movement, such as is illustrated in Figure e of the drawings, the arm moving inward from the eXtreme position indicatedgat a to a position beneath the uptilt'ed flap of the topmost blank, then in a somewhat semicircular path about the line of fold of the blank as an axis, then outwardly to the position a.

`In order to actuate the suction cups 4011i' suitably timed relation with the movements of the folding arms 82, the shaft 60' is preferably driven by suitable connections from the motor' |00. As shown, a vertical shaft |is connected by bevel gears |32 to the shaft |06 so as to be driven thereby. At the upper end ofthe shaft V|30 is a worm ld which meshes with a gearv |35 mounted on a horizontal shaft |33. This shaft is connected by bevel gears to a short vertical shaft |42 on which is also mounted a gear wheel Ille. The latter meshes with a larger gearv wheel IE6 which is mounted on top of the main frame to rotate about a pivot |48. The' large gear wheel drives a smaller gear wheel whichis connected by bevel gears |52 to the shaft 60.

For the actuationl of the pusher 8B', a connecting link |54 is pivotally connected, as at |56; to an eccentric point of the gear wheel |46, the other end or the link |54 carrying a; pin lstwhich `slides ina slot |62 in the main frame'. Rotatably mounted on the pin is a pinio'nQl54 which meshes with Va xed rack |56 and also with a sliding rack |58. Thera-ck' |68 hasan extension |"|0,at the end of which is apin |12V carrying a pinion |14 which meshes with av fixedI rack |15 and a sliding rack H82 Thevp'u'sher is mounted on an arm which is secured tov the rack |76 and projects downward therefrom, as shown in Figure 2. The pinions v|64 and |14, together with the fixed and movable racks with whiehthey are meshed, are for the purpose of multiplying the strokes of the stud shaft |60 at the end of the link |54 so that the-pusher 86' will travel through a considerably greater distance in pushing thefolded blanks, one by one', from the top of the stack.

The long screws 28 which elevate the platform 24 onwhich the stack of blanks is carried are operatively connected to one or both ofthe-sliort shafts H2 by any `suitable means suchas-l bevel gears |84 and |86, the latter being mounted on a shaft |88 which also carries a pulley |90. A belt |92 connects the wheel |90 with a corresponding pulley |94 mounted on a shaft |96v on which is also mounted the gear wheel H4. Thus, with every revolution of the gear wheel H4 the stack of blanks is elevated a predetermined amount substantially equal to the average thickness of a blank.

I claim:

1. A machine of the class described, comprising a magazine for holding a stack of paper box blanks to be folded, hold-down means bearing on the mid-portion of the topmost blank in the stack, and means for folding the end portions of. the topmost blank over upon the mid-portion thereof, said folding means including a suction cup arranged to engage the upper face of an end portion of the topmost blank at a point spaced from the line of fold of said end portion, means for causing said cup to travel upward in an arcuate path concentric with said line of fold and thereafter to swing out beyond the end edge of the blank, means for completing the folding of said end portion, and means for driving said cup actuating means and said completing means in timed relation.

2. A machine of the class described, comprising a magazine for holding a stack of paper box blanks to be folded, hold-down means bearing on the mid-portion'of the topmost blank in the stack, means for initially bending the end portions of said topmost blank up to inclined positions, said means including suction cups arranged to engage said end portions and mechanisms for moving said cups through predetermined paths, automatic means for engaging under said inclined end portions and completing the folding of said end portions over on the mid-portion, and means for thereafter discharging the foldedblank from the stack.

3. A machine of the class described, comprising a magazine for holding a stack of elongated paper box blanks, the end portions of which are to be folded over the mid-portions, hold-down means engaging the mid-portion of the topmost blank in the stack, a suction cup movable to engage each end portion of the topmost blank, a supporting frame for each said cup operable to lift the cup from a position upon the adjacent end portion of the top blank through an arcuate path approximately concentric vwith the axis of fold of the said end portion of the blank to elevate said end portion to an inclined position with reference to the plane of the mid-portion, said frame being further operable to swing the cup outward to clear the corresponding end of the blank so as not to interfere with the completion of the folding of the end portions, means for actuating said supporting frames to cause the cups carred thereby to describe said arcuate paths and perform said outward swings in a predetermined time relation.

4. In a machine for folding the end portions of a paper box blank over the mid-portion thereof,

a suction cup arranged to engage the upper face of an end portion of a blank to be folded at a `point spaced toward the end of the` blank from the nearest line of fold, a vertical support member having said cup secured to its lower end, a fixed pivot in substantial alignment with said line of fold, a lower link rockable at one end about said xed pivot and pivotally connected at its upper end to said vertical support member at an intermediate point thereof, spring means at the joint of the link and vertical member tending to rock the lower portion of said vertical member toward said link, a stop to maintain a minimum angle between said vertical member and link, an upper link pivotally attached to the upper end of said vertical member, means for periodically actuating said upper link to rock said vertical member and lower link as a unit about said fixed pivot, and a fixed stop engageable by said lower link to stop the rocking thereof at a predetermined point, whereby further movement of said upper link results in rocking said vertical member relatively to the lower link, whereby the cup at the lower end ofthe vertical member is swung out clear of the end of the box blank.

5. Apparatus of the class described, comprising means for supporting a paper box blank in a horizontal position, means for rocking an end portion of said blank upward about its line of fold through an acute angle, and means for completing the fold of said end portion, the last mentioned means including a horizontal rod extending transversely with respect to the long axis of the blank, two supporting links each pivotally secured at its upper end to the same end of said rod, two cranks rotatable about parallel axes and connected respectively to the lower ends of said links, and common means for driving said cranks in timed relation.

6. In a machine for folding paper box blanks, means for folding an end portion of a blank over upon its mid-portion, said means comprising a pusher element adapted to engage under said end portion at a point spaced from the line of fold and means for moving said pusher element through a predetermined path, said moving means including two cranks of different length mounted to revolve about parallel axes, driving connections for rotating the shorter crank at twice the angular speed of the longer crank, and links operatively connecting each crank to said pusher element.

HUGH E. MONTGOMERY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 669,027 Crosby Feb. 126, 1901 1,742,863 Jurgens Jan. 7, 1930 2,055,984 Pepper Sept. 29, 1936 121,113,052 Kemp Apr. 5, 1938 2,336,507 Shields Dec. 14, 1943

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