US3390876A - Blank feeding means for folding apparatus and the like - Google Patents

Description

E. W. CLEM July 2, 196s BLANK FEEDING MEANS FOR FOLDING APPARATUS AND THE LIKE July 2 E. wc| EM 3,390,876

BLANK FBEDING MEANS FOR FOLDING APPARATUS AND THE LIKE med Feb. 25, `1966 5 sheets-sheet 2 INVENTOR. EVERETT W. CLEM ATTORNEYS E. w. CLL-:M 3,390,876

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E. W. CLEM July Z, 1968 BLANK FEEDING' MEANS F'R FOLDING APPARATUS ANDA '.IHE LIKE 5 Sheets-Sheet 5 Filed Feb. 25, 1966 FIG.6

INVENTOR. EVERETT W. CLE M ATTORNEY United States Patent 3,390,876 BLANK FEEDING MEANS FOR FOLDING APPARATUS AND THE LIKE Everett W. Clem, Shrewsbury, Mass., assignor to Specialty Equipment Corporation, Westboro, Mass., a corporation of Massachusetts Filed Feb. 25, 1966, Ser. No. 530,106 11 Claims. (Cl. 271-32) ABSTRACT F THE DISCLOSURE This invention is concerned with an apparatus for precisely and flexibly handling corrugated carton blanks often of asymmetrical configuration, and typically supplying them to a folder-taper or folder-gluer machine. The speciication discloses a novel vacuum conveyor system incorporating mobile suction boxes having a significantly smaller suction area than the area of the suction belt available to convey the carton blanks. The suction boxes may also include movable valve plates for providing additional fiexibility to the adjustable suction boxes. An auxiliary feed roll for imparting a forward impetus to Va blank, :at the bottom of a vertical stack as well as a pull roller assembly for supplying the blanks from the vacuum conveyor to the folding machine are also disclosed.

The present invention is ydirected to facilities for feeding blanks for corrugated board cartons, and is directed specifically to improvements in feed table :arrangements for feeding the lowermost corrugated board blank from a stack of such blanks, and 4advancing the blank reliably and accurately into a processing apparatus, such as a folder-gluer or folder-taper, for example.

In the manufacture of shipping cartons formed of corrugated board, it is often desirable to feed the blanks, one at a time, into a folder apparatus or the like, whic-h advances the corrugated board blank longitudinally, while performing a series of manipulative operations thereon, such as scoring, gluing, folding, securing, etc., the general sequence of operations being well known. In the handling of the corrugated blank, it is important to maintain accurate alignment and squareness, lso that the various folding and closing operations are properly performed and the discharged product, in the form of a flat tube, usually secured by glue or tape, is properly squared and aligned. This sometimes proves to be rather difiicult, in connection with corrugated board blanks, partly because of an inherent tendency of the blanks to assume a bowed or curved configuration in storage and, of perhaps greater importance, because of an increasing tendency to package goods in corrugated containers of :a somewhat complex nature, involving highly asymmetrical, die-cut blanks. The facilities of the present invention are aimed particularly at the handling of bowed and/or highly asymmetrical blanks with precision and accuracy, although it will be understood that the facilities will be equally applicable to more conventional, generally rectangular blanks.

In accordance with one of the general objectives of the invention, an improved vacuum feed table means is provided for a folder-gluer, folder-taper machine or the like, which is adapted in a highly effective, precise, and controlled manner, to feed corrugated blanks of Various sizes, shapes, and configurations on a one-at-a-time basis from the bottom lof Ia stack of such blanks. Heretofore, for this general purpose, it has been proposed to utilize vacuum-actuated feed belt means, and the present invention contemplates the use of such vacuum-actuated feed belt means but incorporates therein improvements of a significant nature,gresulting in a substantial improvement in the ability of the feed table system to advance 3,390,376 Patented July 2, 1968 FPice asymmetrical blanks under control and precise alignment and, at the same time, improving the overall eiciency of the equipment.

More specifically, the `apparatus of the invention includes a vacuum-actuated feed table facility in which a perforated conveyor belt means (advantageously comprising a plurality of belts) is advanced in a generally horizont-al traverse over Suction chamber means arranged to lie adjacent the leading edge area of the lowermost corrugated carton blank of a stack thereof. Conventionally, the perforated belt has a width suitable to accommodate a blank of the maximum width capable of being handled by the feed table and the folding lapparatus. Uncharacteristically, however, and in accordance with one aspect of t-he invention, the suction chamber means advantageously has a capacity which is greatly less than the maximum width capacity -of the machine (typically half or less) and is comprised of a plurality yof independently transversely movable suction boxes. In accordance with the invention, the independently Vadjustable suction boxes may be manipulated to lie under are-as of the blank where maximum vacuum effectiveness is desired, and, in a like vein, removed from areas where, by reason of a die-cut recess, for example, the presence of a suction box would be useless, yor at least wasteful of the s-uction effort, and possibly even detriment-al.

In accordance with another specific aspect of the invention, suction box facilities are provided, advantageously of the type and having the characteristics mentioned in the preceding paragraph, which are provided with `a plurality of transversely spaced, longitudinally elongated vacuum openings, each controlled by a sliding door or similar valve device, enabling the several suction openings of each suction box to be selectively opened and closed or partially opened land closed. By variably adjusting the length of the individual suction openings, one can optimize the suction effort, and avoid undue leakage at the back of the openings when handling severely bowed blanks.

As will be made apparent, the precise and highly ilexible suction control afforded by the apparatus of the invention enables unusually configured blanks to be handled with extraordinary effectiveness, which is most important, and with minimized power utilization and equipment wear, which is a secondary although significant consideration.

In accordance with -another specific aspect of the invention, an improved vacuum feed table is provided for corrugated carton blanks which includes a longitudinally Iadjustable transversely disposed auxiliary feed roller element arranged to engage and support the rear edge extremity of a blank Waiting to be advanced by the feed table facility, the 'arrangement being particularly characterized by the provision of a novel and improved, tiltingly adjustable support for the auxiliary feed roller element, enabling it to be raised and lowered as necessary to accommodate various amounts of bowing or larcing which may be present in the corrugated blanks supplied to the feed table. The improved adjustable facility enables the a-uxiliary'feed roller to be located in its most effective position quickly and precisely, so that change-over time for converting the feed table to handle a new size and shape of blank is greatly minimized.

In accordance with another significant aspect of the invention, novel and improved pull-out roller means are provided in conjunction with the feed table or other facility supplying corrugated blanks, which precisely grip and advance successive' corrugated blanks and maintain them in accurate alignment, as desired. In this respect, it will be understood that the pull roller facilities of the yapparatus must have a length suitable to accommodate a blank of maximum width yet frequently will be called upon to handle blanks of only a fraction of that width, which may or may not be precisely centered with respect to the ends of the pull rollers and may or may not be of symmetrical configuration. Heretofore, this has resulted in significant diflicuties in maintaining proper alignment during the passage of the blank through the pull-out rollers. In accordance with the present invention, duplicate, resiliently covered pull-out rollers are provided, which are adjustably mounted to accommodate corrugated carton blanks of the various conventional flute thicknesses. The new adjustment facilities include a stepped abutment gauge at each end, for precisely and rigidly setting the pull-out gap and eliminating from the adjusting system all effects of thread and gear backlash, etc., which, even though of only a few thousandths of an inch in magnitude, is sufficient to tilt the adjustable roll and throw a blank out of desired alignment.

Advantageously, the pull-out roller arrangement, as described above, includes rubber-covered pull-out rollers, the rubber surfaces of which are annularly grooved at closely spaced intervals across their working widths. When the pull-out rollers are properly adjusted for a given flute height of corrugated board, the actual roll gap is somewhat narrower than the actual thickness of the corrugated board, in order to provide for adequate gripping, and the provision of annular grooves enables the rubber surfacing material to be distorted or displaced laterally into the groove areas. This minimizes circumferential distortion and displacement and thus further enhances the accuracy of control over the blank as it passes through the pull-out rollers.

For a better understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description and to the accompanying drawing, in which:

FIG. 1 is a side elevational view of a feed table apparatus incorporating the various features of the invention;

FIG. 2 is a fragmentary cross-sectional view, as taken generally along line 2-2 of FIG. 1;

FIG. 3 is an enlarged, fragmentary view, similar to FIG. 1, showing details of a suction box adjustment facility and of the pull-out adjustment facility;

FIG. 4 is an enlarged, fragmentary, cross-sectional view, as taken generally along line 4 4 of FIG. 3;

FIG. 5 is an enlarged, fragmentary, cross-sectional view, as taken generally along line 5-5 of FIG. 4; and

FIG. `6 is a top plan view of a suction box assembly incorporating the principles of the invention.

Referring now to the drawings, and initially to FIG. 1 thereof, the reference numeral 10 designates generally a frame structure for the vacuum feed table arrangement of the invention, which is arranged to be positioned adjacent, or to form an integrated part of, a corrugated blank processing facility, such as a folder-gluer or foldertaper, for example. A typical apparatus for this purpose is illustrated in the Everett W. Clem U.S. application Ser. No. 224,951, tiled Sept. 20, 1962, and/or in the Everett W. Clem U.S. application Ser. No. 523,347, filed on Ian. 27, 1966.

In the apparatus illustrated in FIG. 1, the frame structure 10 supports a plurality of rollers 11, 12, 13 arranged in a generally triangular configuration and training a perforated suction belt 14 advantageously consisting of several (eg, three) side-by-side belt sections. The rollers 12, 13 are so arranged that the belt has a generally horizontal upper traverse, and one of the belt rollers 11 is driven to impart a forward (left to right) motion to the perforated belt on its upper traverse. Between the upper belt rollers 12, 13 there may be provided an appropriate plurality of idler rolls 15, which support the perforated suction belt 14 along its horizontal, forward traverse. The roller 12 is divided into three roller sections, each arranged for cooperation with one of the belt sections. The separate roller sections are independently adjustable, longitudinally of the table axis, for initial tension adjustment of the separate belt sections. A tension control idler 15a, mounted on a pivot arm 15b and adjusted by a screw 15C, may be provided for simultaneous tension adjustment of all belt sections subsequent to setting of the roller sections 12.

Spaced well above the forward portion of the suction belt 14 is a transverse bar 16, which slidably supports a plurality of guide arms 17. The outermost of the guide arms 17 support guide plates 18, which are disposed in a vertical plane, aligned with the centerline of the machine and extend to a point closely above the upper traverse of the suction belt 14. The guide plates 18 extend from forward abutment plates 19, arranged to engage the front edges of a plurality of corrugated carton blanks 20 arranged in a vertical stack. Actually, as illustrated, it is desirable and intended that the vertical stack will be tilted backward slightly from bottom to top, by the slight offsetting of each blank relative to each adjacent blank, to facilitate the one-at-a-time feeding of the lowermost blank olf the stack, in rapid sequence.

As will be understood, an opposed pair of corner guides, each comprising a side guide plate 18 and a front edge abutment 19, can be adjusted to guide and confine the front corner regions of a stack of corrugated carton blanks, at least where the blanks are of generally rectangular conguration. In conjunction therewith, and in some cases alternative thereto, it is usually desirable to provide one or more intermediate guides in the form of blades 21 arranged to be received in cut-out slots 22 (see FIG. 2) in the carton blanks 20. As will be understood, where the corrugated blanks are of unusual or asymmetrical configuration, it may be impractical to use the corner guides 18, 19 effectively, in which case the stack of blanks is guided and aligned entirely by one or more of the guide blades 21.

As shown in FIG. 1, the guide elements are provided with an adjustment facility 23 permitting their lower edges to be raised and lowered relative to the top surface of the suction belt 14. The arrangement is such as to provide for a gap adjustment above the suction belt, accommodating the passage of a single corrugated blank of given thickness but not more than one blank at a time.

In the illustrated apparatus, the various guide elements 18, 19, 21 are supported along their lower edges by means of a transverse bar 24 supported by the machine frame, which is arranged to engage and support opensided bearing elements 25. The arrangement desirably is such that any one of the guide elements may be slid or raised to an out-of-the-way position. The element may be secured in its out-of-the-way position or in its adjusted, in-use position by means Stich as a hand wheel tightener 26. Where odd shaped, die cut blanks are to be handled, one or more of the guide elements may be padded out with blocks lfor proper engagement with leading edge portions of the blanks.

Pivotally secured to the principal table frame 10 by means Iof pins or the like are a pair of support -arms 31 which extend in a generally rearward direction, typically from a point intermediate the upper traverse of the suetion belt 14 to a point well to the rear thereof, the arms 31 being arranged in straddling relation to the suction belt, as 'shown particularly in FIG. 2. Slidably guided in the support arms 31 for movement longitudinally thereof is an auxiliary feeding carriage 32 which rotatably supports. in its forward portions an auxiliary feeding roller 33, shown particularly in FIG. 2. The auxiliary feeding roller 33 advantageously is provided with a knurled outer surface and may be freely journaled in the carriage 32 or lightly driven by means such as a stalltorque motor.

As shown in FIG. l, the carriage 32 advantageously is adjusted longitudinally of the support arms 3l, to a puirt such that the lowermost back edge extremity of the lowermost carton blank rests upon and is supported in an elevated position by the auxiliary roller 33, advantageously at a point near the forward extremity of the roller (e.g., 30 to 45 above a horizontal plane through its axis) such that the downward force of the weight of the stack 34 of blanks tends to drive the auxiliary roller 33 in a clockwise direction, simultaneously imparting a slight forward force component to the lowermost blank to break it free of the stack and start its forward advancing movement under the primary influence Iof the suction belt 14 as will be described. Usually, it -is adequate to simply freely journal the lauxiliary roller 33 Vand let it be actuated by the downward merging of the stack of blanks. However, it may be advantage-ous to drive the roller by means, such as a stall-torque motor, for example, such that a positive, external torque would be applied to the roller to make its action more effective.

As shown in FIG. 1, the auxiliary roller 33 is adjustably positioned longitudinally along the support arms 31 by means of a pinion gear 34 actuated by a hand wheel 35 carried by the carriage 32 and which meshes with a rack 36 formed along the upper edge area of the support arm 31. A similar rack and pinion facility may be provided at the other side of the machine, for simultaneous manipulation by the hand wheel 35, as will be understood. A-fter the carriage 32 has been advanced into a position as illustrated in FIG. 1, it may be locked in such position by means of lone or more hand screws 37 at each side of the machine.

The typical proportions and location of the auxiliary feeding roll 33 are such that, in the horizontal position of the supporting arms 31, as illustrated in FIG. 1, the auxiliary feeding roller 33 will properly accommodate corrugated carton blanks having a typical degree of bowing or arcing, substantially as illustrated. However, since the nature and extent of such :bowing or arcing is, to a large degree, lout of the control of the processor and is linuenced by such factors as age, humidity, original manufacturing techniques, etc., occasional batches of carton blanks may be bowed to a much greater extent than the blanks illustrated in FIG. 1. To accommodate such greater degrees of bowing, the support arms 31 are pivotable upward about the pins 30, so that the auxiliary feeding roller 33, which serves to support the Iback edge of the lowermost blank, can be raised to a considerably greater height above the plane of the suction belt 14. The appropriate adjustment facility is provided by means of a hand crank 38 operating through a worm gear 39 to raise and lower a screw shaft 40 at each side of the machine. The adjusted, pivoted position of the support arm at each side may then be xed by means of hand screw tighteners As will be understood, the proper adjustment of the pivotable supporting arms 31 is such that the forwardmost leading edge area of the bottom blank lies substantially horizontally lalong the upper traverse of the suction belt 14, so as to lbe effectively -gripped by suction applied through the belts.

Advantageously, the carri-age 32 carries one or more adjustable guide blades 42 arranged to be locked in la preset transverse location by means of a locking device 43 of suitable form, such that the blade 42 is received in a cut-out slot 44 in the back edge of the corrugated carton blank. The 'blade 42, in conjunction with the corner guides or one or more similar guide blades disposed at the front of the stack of blanks, serves to maintain precise alignment of the blanks with respect to the centerline of the equipment, as will be understood.

In accordance with one of the particularly important yaspects of the invention, novel and improved suction facilities are provided to act upon the upper, horizontal traverse of the suction belt 14 immediately adjacent the forward roller 13. While such suction arrangements are, in general, known and'widely used, the provisions of the present invention are such that suction is applied only to areas of limited transverse extent, the exact location and the overall extent of which is widely preadjustable to accommodate in an optimum manner the specific conguration of the corrugated blank then being handled by the equipment.

In accordance with this aspect of the invention, the feed table apparatus includes a plurality, mo-st advantageously four in a machine of conventional capacity, of individual suction -boxes 50, `arranged across the width of the machine but having a total effective width considerably less (usually under half) of the maximum eifective vacuum width of the machine. Each of the suction boxes 50 is provided with ange- s 51, 52 slidably received in supporting plates 53, 54 in the machine frame, whereby the suction boxes are freely slidable transversely of the machine, in a horizontal plane below the upper traverse of the suction belt. A pair of parallel, transversely disposed tubes 55, 516 passes in similar relation through the main chamber 57 of each of the suction boxes to accommodate the passage of threaded adjusting rods 58-61, there being a pair of threaded adju-sting rods accessible from each side of the machine, such that, in the illustrated apparatus, utilizing four independent suction boxes, there is a separate, threaded adjusting rod for each independent suction box.

In the illustrated arrangement, the outboard suction box on the righthand side, shown in FIG. 4, is provided with a threaded bushing 62 arranged for threaded engagement with the adjusting rod 58. The rod 58 then passes through the corresponding tube 56 provided in the inboard right side suction box, without making engagement therewith, and the inner end of the -rod is then journaled in a frame bearing 63 in the center of the machine frame. The second threaded adjusting rod 59 provided on the righthand side of the machine passes through the tube 55 of the outboard box, without engagement, and is engaged by an appropriate threaded bushing 64 in the inboard box, and the rod 59 is likewise supported 'by the frame bearing 63. The arrangement is such that the inboard and the outboard suction boxe-s on the righthand side of the machine may be independently adjusted transversely of the suction belt 14 by selective manipulation of the threaded adjusting rods 5? 59. In a similar manner, not requiring separate specie description, the inboard and outboard suction boxes on the lefthand side of the machine are separately and independently adjustable 'by appropriate manipulation of threaded adjustment rods 60, 61.

For the convenient and Iadvantageous adjustment of the threaded rods 58, 59, each is provided with a pinion 65, 66 offset axially from the other. A drive gear 67, secured to a hand wheel 68, may be shifted axially along a shaft I69, for driving engagement selectively with either one or the other of the pinions 65, 66 (or the pinions may be shifted axially, if preferred).

In the illustrated apparatus, the overall transverse width of the suction boxes 50 may be on the order of 1/3 the useful width of the vacuum belt 14, so that the combined vacuum box width is somewhere on the order of 1/2 that of the vacuum belt. The actual available vacuum area of the suction boxes may be somewhat less than this, say on the order of 35% of the capacity of the machine. Accordingly, with blanks of different sizes, the individu-al suction boxes may be disposed transversely underneath the suction belt 14 in an optimum manner, calculated t-o achieve reliable advancement of the bottommost blank of a stack, without unnecessary wastage of suction capacity and without unneeded suction effectiveness, which serves merely to accelerate wear of the suction belt and other parts of the equipment, as well as to scuif and mark the blank, which may bear incompletely cured printing inks.

As shown in FIGS. 4-6, each of the suction boxes 50 has a front suction chamber, communicating with a suction outlet 70 arranged to be connected through a suitable exible yduct (not shown) to a suitable vacuum source (also not shown). The suction chamber, 57, advantageously extends throughout the entire width of the suction box and is provided with a plurality of longitudinally elongated inlet openings 71 along its top surface. Typically, the openings 71, in conjunction, constitute substantially the entire upper surface of the suction chamber, being separated by relatively narrow longitudinal supports 72 and bounded at the ends by relatively thin end wall sections 73.

In accordance lwith a specific aspect of the invention, each of the longitudinally disposed openings 71 is provided with a longitudinally adjustable closure plate 74, which is arranged for longitudinal movement from a first position in which the opening 71 is fully closed to a second position in which the opening is entirely free of obstruction, being also capable of being set at any intermediate position to partially close olf the suction inlet opening. Advantageously, the closure plates 74 have beveled edge areas 75 slidably received in dovetail guide slots 76 adjacent the edges of the suction inlet openings 71.

As shown in FIGS. 5 and 6, portions of the closure plates 74 extend rearward beyond the back wall of the suction chamber 57, overlying a supporting flange 79 which projects horizontally rearward from the suction chamber. The supporting flange 79 is provided with a plurality of vertical guide surfaces S3 Aforming guide grooves 85, in which are slidably received, guided, and supported a plurality of slide blocks 78 secured to the projecting rear portions of the valve plates 74, as by means of screws 84. Suitable :bolts 81 extend through the slide blocks 78 and engage nuts 82. The nuts 82 are arranged to bear against the bottom surface 86 of the supporting ange 79 and have upwardly projecting tongues or keys 87 received in elongated slots 88 formed in each of the guide grooves 85. The arrangement is such that the closure plates 74 may be freely moved longitudinally from fully opened to fully closed positions, or to any intermediate position, and locked in such position by means of the bolts 81 and nuts S2.

As indicated schematically in FIG. 4, the outboard suction boxes at least advantageously may be connected through suitable individual control valves 90, 91 and a common suction header 92 to a suitable suction source such as the intake of a compressor or blower 93, for example. For proper suction control a bleeder valve 94 may be provided just upstream of the suction source.

In accordance with another specific aspect of the invention, novel and improved pull roll means are provided, most advantageously for use in conjunction with the above-described feed table apparatus, but also suitable for use in conjunction with other facilities for the supply of corrugated carton blanks from a feed source and their transmission on to a subsequent processing apparatus, such as a folder, for example. The pull roll facilities of the present invention comprise a pair 4of pull rollers 100, 101 (see FIG. 3) which are positioned adjacent the exit or discharge end of the feed table generally in line with the plane in which corrugated carton blanks are -fed one at a time from the table. In accordance with known techniques, the pull rollers 100, 101 advantageously are driven in synchronism at a speed which is somewhat in excess of the speed at which blanks are advanced one at a time by the feed table. Accordingly, as the leading edge of a blank enters the nip formed by the vertically aligned rollers 100, 101, the blank is gripped and forcibly drawn from the feed table and advanced on to a folder or other apparatus located on the discharge side of the pull roller nip. By operating the pull rollers 100, 101 at a slightly higher speed than the feed table apparatus, a predetermined spacing is introduced between successive blanks as they are discharged from the pull roller nip, which is a desirable condition for most processing operations.

In accordance with the invention, means are provided for mounting of the respective pull rollers 100, 101 in such a way as to provide for precise adjustment of the pull roller nip to receive the various standard ilute sizes of corrugated carton blanks. Further, facilities are provided for maintaining precise parallelism between the upper and lower pull rollers, even when handling offcentered or asymmetrical carton blanks, as is often required of a conventional equipment. In the specific apparatus herein illustrated, the principles of the invention are carried out by mounting the lower pinch roller 101 in fixed relation to the machine frame 10, as by means of appropriate fixed bearings 102. The upper pinch roller 100, on the other hand, is mounted vertically above the roller 101, in bearings 103 arranged and guided for vertical adjusting movement in slides 104 carried by the basic frame structure. Screw shafts 105 (FIG. 1) engage the bearings 103 at each side of the machine and are actuated by internally threaded worm wheels 106 driven by worm gears 107 from a common shaft 10S extending transversely across the machine.

As a significant aspect of the invention, there is provided at each side of the machine a stepped gauge block 109 (FIG. 3) supported rigidly 'by a slide pedestal 110 for slidable adjusting movement in the direction of the gauge steps. A handle 111 is provided for convenience of manual manipulation of the gauge block. A gauge bar 112 is fixed to the bottom of the lupper pull roller bearing 103 and is generally aligned over the stepped gauge block 109, such that it may be brought to bear on any of the gauge steps of the block. If desired, detent means or the like may be provided, defining discrete index positions for the gauge block 109, in which the individual gauge steps are located directly under the gauge bar 112.

In accordance with the invention, the individual steps of the gauge block 109 are arranged such that the highest step, at the righthand side in FIG. 3, corresponds to the corrugated carton stock of maximum thickness to be accommodated by the machine. Typically, this would be socalled A flute corrugated board. The other gauge steps, in descending order from right to left, would correspond to corrugated stock thicknesses designated C flute, B flute, D flute, and E flute, for example, these being the conventional grades of corrugated carton board presently commercially handled in large quantities.

As will be understood, the gauge bars 112 and gauge blocks 109 are so related to the diameters of the pinch rollers 100, 101 that, at a given setting of the gauge blocks 109, the pinch roller nip will be slightly narrower than the nominal thickness of the carton stock to be handled, such that the blanks are firmly gripped by the pinch rollers. As shown particularly in FIG. 2, for example, each of the pinch rollers advantageously is provided with a covering of soft rubber or other resilient materials, provided across its entire effective surface with alternating annular grooves and lands 113, 114. The arrangement is such that, as a corrugated carton blank is advanced into the pinch roller nip, it is gripped resiliently by the respective annular lands 114 of the upper and lower pinch rollers, accelerated to the peripheral speed of the pinch rollers, and advanced through the pinch roller nip. Desirably, the dimensions and spacing of the annular grooves and lands 113, 114 is such that, when the resilient covering material of the annular lands 114 is deformed by the application of gripping pressure to a corrugated carton blank, at least some of the deformation is accommodated by sideways or axial deformation of the resilient material into the area of the grooves 113. By thus reducing the extent of circumferential distortion, more positive and accurate feeding of the carton blanks is assured.

As one of the important advantageous features of the new pinch roll structure, the actuating arrangements for the movable upper pinch roller 100 is arranged to drive the gauge bars 112 solidly down onto the preselected steps of the gauge block 109, with a force reliably in excess of any reaction force applied to the pinch rolls upon entry of a corrugated carton blank into the pinch roll nip. Desirably, the actuating mechanism for raising and lowering the upper pinch roller 100 includes essentially nonresilient elements, such as the screw shaft 105, threaded worm wheel 106, etc., which, when screwed down tight against the gauge blocks, is free of backlash and relatively non-yielding. However, if there were occasion to utilize pneumatic, hydraulic or spring-loaded means for actuating the pinch rollers toward and away from each other, the effective force thereof would be such as to reliably and substantially exceed any reaction force resulting from entry of a carton blank into the nip, so that the gauge bars 112 would be retained solidly against the preselected step of the gauge bars 109. In this respect, it will be understood that the pinch rollers 100, 101 of a typical machine are of substantial length (e.g., 100 inches) and may at any given time be handling a carton blank of very small dimensions, which may be entering the pull roller nip along an axis offset from the centerline of the machine, either by reason of the initial alignment ofthe blank or by reason of its asymmetrical outline, or both. In such cases, even a slight tilting of the pinch rollers out of parallel relationship, as might result in a conventional apparatus through backlash in the adjusting means, yielding of resilient supports, etc., may cause the blank to be skewed slightly out of its precise initial alignment. This will, of course, undesirably affect subsequent processing operations such as folding and securing, and is particularly undesirable where the subsequent processing includes the operation of securing the folded carton blank by taping. With a carton secured by taping, misalignment of the seam will cause the tape to be applied across the seam rather than along the seam. Further, if the folded carton tube is not secured in precisely squared condition, there is no opportunity to correct the condition in a subsequent squaring operation, as often may be done where the carton is secured by gluing, for example.

The feed apparatus of the invention is particularly advantageous overall for the precise, controlled feeding of corrugated carton blanks one at a time, in accurate alignment, so that subsequent processing operations may bel performed in a most expeditious and effective manner. The equipment of the invention, although incorporating features providing for full adjustability, to accommodate corrugated carton blanks of all sizes, shapes, and thicknesses, provides for precision of handling and control heretofore unattainable in a universal machine.

One of the significant advantageous features of the feed table apparatus resides in the provision of independently movable, small area suction boxes, which may be selectively positioned and actuated and may be regulated individually as to suction power, such that suction effort may be applied to the carton blanks in selected areas where it will achieve optimum effectiveness, and the overall suction effort is kept at a practical minimum to reduce drag on the blank after it has been engaged by the pull roller. In this respect, it will be understood that the pull rollers desirably advance the blank at a speed greater than that of the suction belt. Accordingly, excessive suction drag on the blank consumes unnecessary power, causes excessive and unnecessary wear on the machine parts, and, probably of greatest significance, will tend to cause misalignment of the blank, particularly in the case of asymmetrical die cuts and the like.

The new suction box arrangement also includes a large plurality of longitudinally slidable, relatively narrow closure plates which control the longitudinal extent of each of a plurality of longitudinally elongated suction openings. This enables the suction pattern to conform better to odd shaped die cut blanks and also enables avoidance of excessive suction loss at the rear of the normal full suction opening, which would be experienced with severely curved blanks. If desired, of course, the slidably adjustable closure plates could be utilized with a continuous, full-width suction box, for example, being selectively opened, controlled, and adjusted for desired suction effects.

The new feed table also includes an advantageous supporting arrangement for an auxiliary feeder roll arranged to contact and impart a slight forward impetus to the back edge portion of the lowermost blank of a stack. The facilities of the present invention include a novel and improved arrangement for adjustably locating an auxiliary feeding roll, so as to contact the back edge of the blank at a precise location, regardless of the extent of bowing or curvature of the blank or of its dimensions, within the capacity limits of the machine.

As will be understood, the various inventive features described herein are most advantageously employed in combination, but are also susceptible of separate utilization, as circumstances demand or permit. Likewise, the specific forms of the inventive features herein illustrated and described are intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

What is claimed is:

1. A vacuum feed table for advancing corrugated carton blanks or the like, which comprises (a) a table frame,

(b) a perforated belt movably carried -by the table frame and having a predetermined exposed traverse in which the bel-t may be exposed to a corrugated carton blank or the like,

(c) said belt having a predetermined belt width,

(-d) a plurality of suction boxes mounted adjacent the concealed side of said belt over a portion of its exposed traverse,

(e) the plurality of said suction boxes having a total effective width significantly less than said predetermined belt width, and

(f) means for independently adjusting at least certain of said suction boxes with respect to said perforated belt, whereby to cause suction to be applied through said belt at preselected limited areas thereof.

2. A vacuum feed table `according to claim 1, further characterized by (a) there being a plurality of at least four suction boxes,

(b) the combined effective suction width of said boxes being less than half the effective suction width of the belt, and

(c) each of said boxes being independently movable relative to said belt.

3. A vacuum feed table according to claim 2, further characterized 4by (a) means mounting 'said suction boxes in transverse alignment along an axis extending across the width of said belt, and

(b) means accessible from the sides of said feed table for effecting transverse adjustment of said boxes along said axis.

4. A Isuction box, for use in a vacuum feed table for corrugated carton blanks tand the like and in combination with a perforated feed belt, comprising (a) means forming a lsuction chamber having a suction opening and a suction outlet, and

(b) a plurality of valve plates disposed in side-by-side relation Iacross the transverse extent of said suction chamber and lselectively movable between open and closed positions, said valve plates forming a flat surface for the partial support of a suction belt or the like.

5. A suction box according to claim 4, further characterized by (a) said valve plates being elongated in a longitudinal direction and adjustable longitudinally to form individual suction chamber openings of variable longitudinal dimension.

6. A vacuum feed table for advancing corrugated carton blanks or the like, which comprises (a) a perforated suction belt having a predetermined suction width.

(b) means for supporting and advancing said suction belts through a predetermined exposed traverse in which lthe belt may be exposed to a corrugated carton blank or the like,

(c) a suction box cooperatively related to said belt for applying suction to a preselected limited area thereof in the region of said exposed traverse,

(d) said suction box having an effective suction Width significantly less than said predetermined suction width in the region of said exposed traverse, and

(e) means for adjustably positioningy said suction box relative to said belt within said region.

7. A vacuum feed table according to claim 6, further including (a) suction box means additional to and separate from said suction box positioned for cooperative suction relation with a portion of said suction belt in the region of said exposed traverse.

8. A vacuum feed table according to claim 7, further characterized by (a) said suction box means being adjustably movable relative to said belt in said region and relative to said suction box.

9. A feed table for advancing corrugated carton blanks from the bottom of a stack, comprising (a) a movable belt having a traverse portion contacting the forward edge area of a blank,

(b) an auxiliary feeding roll positioned adjacent the rear edge of a `stack of blanks for imparting a forward impetus to a blank,

(c) first means to adjust said auxiliary feeding roll generally in forward and rearward directions, and

(d) second means for adjusting said auxiliary feeding roll vertically relative to said traverse portion of the belt.

10. A feed table according to claim 9, further characterized by (a) said second means comprising a pair of pivot arms disposed in straddling relation to said belt,

(b) said rst means comprising a roll supporting carriage mounted by said pivot arms for movement toward and away from the pivot axis thereof.

11. A feed table accordingf to claim 1t), further characterized by (a) said traverse portion of the belt being disposed generally horizontally, for advancing carton blanks in a generally horizontal plane from the bottom of a generally vertical stack of generally horizontally -oriented blanks,

(b) said auxiliary feeding roll being disposed in predetermined adjustable operating positions generally above the plane of said traverse portion.

EDWARD A. SROKA, Primary Examiner.

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