US2995361A

US2995361A - Feeding equipment

Info

Publication number: US2995361A
Application number: US849043A
Authority: US
Inventors: John P Lopez
Original assignee: Universal Corrugated Box Mach
Current assignee: Universal Corrugated Box Machinery Corp
Priority date: 1958-07-01
Filing date: 1959-10-27
Publication date: 1961-08-08
Anticipated expiration: 1978-08-08
Also published as: GB920743A; DE1146347B; GB920744A; US3122069A

Description

wtf:-

A1lg- 8, 1961 J. P. LoPEz 2,995,361

FEEDING EQUIPMENT Original Filed July l, 1958 5 Sheets-sheet 1 INVENTOR gbr/N P LOPEZ.

ATTORNEY.;

Aug. 8, 1961 J. P. LoPEz FEEDING EQUIPMENT Original Filed July 1, 1958 77 76 |I i.. Il

5 Sheets-Sheet 2 Iffff/f- ATTO R N EYJ.

INVENTOR HN P LOPEZ.

5 Sheets-Sheet 3 J. P. LOPEZ FEEDING EQUIPMENT lilllQlllIIIl A@ wh Aug. 8, 1961 originan Filed July 1, 1958 INVENTOR \DHN P LQPEZ. MMM

ATTORNEYS.

Aug. 8, 1961 J. P. LOPEZ FEEDING EQUIPMENT 5 Sheets-Sheet 4 Original Filed July 1, 1958 NVENTOR JOHN POPEZ.

MMM

ATTORNEYS.

AU8- 8, 1961 J. P. LoPEz 2,995,361

FEEDING EQUIPMENT Original Filed July 1, 1958 5 Sheets-Sheet 5 INVENTOR for/N PLoPEz. BY

United States Patent Office 2,995,361 Patented Aug. 8, 1961 2,995,361 FEEDlNG EQUIPIVIENT I John l. Lopez, Westfield, NJ., assignor to Universal vided and this application 0ct. 27, 1959, Ser. No.

7 Claims. (Cl. 271-32) This invention relates to the art of folded boxblanks and more particularly to equipment for feeding such box blanks.

As'conducive to an understanding of the invention, it is noted that where corrugated box blanks of the type that comprise four panels in side by side relation, that have been pre-scored to facilitate folding of the two outer panels into edge to edge juxtaposition, are successively fed to additional processing equipment such as a folder for such outer panels, if the box blank should skew as it is advanced, it will not fold properly and may cause jamming with resultant stoppage of the equipment for removal of the jammed blanks, with consequent waste thereof.

In order for the subsequent processing equipment to operate at a high rateof speed, which is essential for mass production, it is vital that the open box blanks be fed automatically and rapidly in sequence thereto, with substantially no skewing or hesitation in its advance which would cause improper processing of the blanks, such as improper folding of the outer panels of the box blank and jamming of the folding equipment where the subsequent equipment is a folder or improper slitting thereof where the subsequent equipment is a sltter.

Where reciprocating means such as a pusher is used successively to feed the open box blanks, the rate of feed is necessarily slower than it would be with a rotary feed and such reciprocating equipment is more likely to break down. In addition, where the box blanks are of the die cut type having irregular edges, the use of a pusher type feeder is substantially precluded, as it would not necessarily engage -a straight edge to advance the box blanks without skewing thereof.

Furthermore, where rectangular sheets of semi-rigid material such as corrugated paper or the like used in the manufacture of folding boxes are to be fed automatically one by one from the bottom of a stack, between suitable drive means which discharge individual sheets for subsequent processing, where, due to unequal contraction or expansion, the sheets tend to warp, the end edge of the successive bottommost sheet in the stack may not be aligned with the drive means with the result that the continuous discharge of the sheets may be interrupted requiring manual realignment of such end edge, thereby interrupting vthe subsequent processing and preventing high speed operation.

Where the stack of box blanks4 rests on a friction belttype conveyor and a stop is positioned over the conveyor in the path of movement of the box blanks immediately above the bottommost blank so that with advance of the conveyor one blank at a time will be fed, as the fn'ctional engagement of the conveyor with the bottommost box blank may not be equal over the entire area thereof, skewing of the bottommost blank may occur as it is advanced with the disadvantages above noted.

It is accordingly among the objects of the invention to provide a box blank feeding equipment especially sultable for corrugated type box blanks, which is relatively simple in construction and has but few parts which are not likely to become deranged even with long use, and which will operate at a high rate of speed dependably to discharge successive blanks from the bottom of a stack without likelihood of stoppage of the discharge operation even if the sheets are warped and do not initially have their end edge aligned with the discharge drive means and with substantially no skewing or hesitation in its advance and which may be used with .box blanks of any type including die eut blanks having irregular edges.

According to the invention, the box blanks are successively fed from the bottom of a stack by means of a suction type conveyor belt in association with a guide arm or gauge which permits only one blank at a time to pass thereunder.

This application is a division of co-pending application, Serial No. 745,979, tiled July 1, 1958.

In the accompanying drawings in which are shown one or more of various possible embodiments of the severa features of the invention.

FIG. l is a top plan view of the feeding equipment in combination with a folder with which it is illustratively shown,

FIG. 2 is a side elevational view thereof taken along line 2-2 of FIG. 1,

FIG. 3 is an end view taken along line 3-3 of FIG. 2,

FIG. 4 is a detail side elevational view of the glue applying rollers taken along line 4-4 of FIG. 1,

FIG. 5 is a side elevational view of the feeding unit partly in cross section,

FIG. 6 is a view taken along line 6-6 of FIG. 5,

FIG. 7 is a fragmentary detail view of an outer back stop taken along lines 7-7 of FIG. 5,

FIG. 7A is a top plan view of an intermediate back stop,

FIG. 8 is an explodedperspective view of one of the outer back stops,

FIG. 9 is a plan view of a box blank in open condition,

FIG. l0 is a view similar to FIG. 9 of a box blank in folded condition,

FIG. 11 is a fragmentary top plan view on an enlarged scale showing the folding discs,

FIG. 12 is a detail side elevational view taken along line 12-12 of FIG. 11,

FIG. 13 is a detail view on an enlarged scale of one of the folding belt guide rollers taken along line 13-13 of FIG. 1, v

FIGS. 14, 15 and 16 are transverse sectional views taken along lines 14-14, 1S-15 and 16-16 of FIG. 1,

FIG. l7 is 'a fragmentary perspective view of the folding unit, and

FIG. 18 is a sectional view on a greatly enlarged scale showing one of the folding discs.

Referring now to the drawings, the equipment comprises a box blank feeding unit 22 which successively advances the open box blanks to subsequent equipment for processing, such equipment illustratively being a folding unit.

The open box blank 23, illustratively shown in FIG. 9, is of conventional type and comprises four; rectangular panels A, B, C and D dened by

score lines

24, 25 and 26; panels A, C and B, D respectively being of the same dimensions, the panels A, D defining the outer panels. The side edges 25 of the panels are suitably scored for ready folding thereof and each of said edges 25, has a rectangular ap 26' extending laterally therefrom. In addition, the end edge 27 of panel A has a connector flap 28 formed integral therewith to which glue may be applied so that when the blank is foldedto the position shown in FIG. 10, the connector flap 28 will be positioned beneath the end edge 27 of panel D and will be secured thereto.

The feeding unit 22 shown in FIGS. 1, 2, 5 and 6 comprises a frame 31 which has a pair of spaced

rollers

32 and 33 mounted on a horizontal axis, said rollers carrying a perforated endless belt 34, the upper run 35 of which is supported by a plurality of spaced idler rollers spense:

36. The rollers are encompassed by a suction chamber 37 connected through duct 38 to a suction unit 39 whereby upon creation of suction in the chamber 37 a corresponding suction will be created through the perforations in the belt 34. As shown in FIG. 6, a pair of racks 41 straddle the belt 34 and are secured to the frame 31, said racks being straddled by the vertical legs 42 of elongated L-shapcd brackets 43, the horizontal legs 44 of which are secured to the frame 31.

Each of the vertical legs 42 of brackets 43 -has an elongated horizontal slot 45 through each of which extends the associated reduced diameter end 46' of a shaft 47 that extends transversely across the belt 34. As shown in FIG. 6, la pinion 46 is secured to each of the reduced diameter ends of the shaft inward of the vertical legs 42 of bracket 43 and adjacent thereto, said pinions engaging the associated rack 41. One end of the shaft has a nut 47 thereon, and the other end mounts a handwheel 48. The shaft 47 extends through bearings 51 in each end of an elongated support 52 that is rectangular in cross section and has its lower ends resting on the frame inwardly of the racks 41 as shown in FIG. 6, said support also extending transversely across the belt 34.

Thus, upon rotation of the handwheel 48, the support 52 will be moved longitudinally of the belt 34, being restrained yfrom rotation by reason of the fact that its ends rest on the frame.

The support serves as a mount for a plurality of box blank guides or back stops 53, each of which, as illustratively shown in FIG. 8, comprises a casting having an inclined front wall 54 with parallel vertical flanges 55 at the side edges extending outwardly from the front wall. Extending rearwardly from the upper and lower ends of the front wall 54 and formed integral therewith are spaced parallel horizontal anges 56 and 57 adapted to straddle the support 52 -and which extend beyond the latter as shown -in FIG. 5. A plate 58 is secured as by screws 59 to the free' ends of said flanges 56, 57 and by means of a set screw 61 extending through a tapped opening in the'plate and reacting against the rear wall of the support 52, the guides 53 may be set to any desired position along the length thereof.

Extending transversely between the parallel vertical anges are spaced parallel shafts 62, each of which illustratively mounts a pair of rollers 63, the rollers on successive shafts being staggered as shown in FIG. 7,

the outer peripheries of said rollers extending beyond the outer edges of anges 55 to serve as a moving support for the rear edges 64 of the box blanks, as willy be hereinafter described.

In the illustrative embodiment shown, three guides 53 are provided, the two outer guides having Itins 65 secured to the outer anges 55 thereof, said tins properly positoning the box blanks on the conveyor belt 34.

In the case of a long box blank, the intermediate guide 53 may have a central lin 65' as shown in FIG. 7A, which fits into the slot 65" (FIG. l) between adjacent aps 26'. As a result of such tin, the long box blank is effectively guided at three points which will prevent skewin4g thereof as the box blank is deposited on conveyor belt 3 Extending transversely across the belt 34 and positioned above the latter adjacent the roller 33 and longitudinally spaced from the guides 53 is a hanger rod 67 from which depends a plurality of guide arms or gauges 68, each in the form of an elongated substantially rectangular bar, the lower end of each guide arm 68 desirably being inzlsined outwardly as shown, to define a detlector portion To mount each .of the guide arms 68, a substantially rectangular block 69 is provided, which has a transverse bore 71 near one end 72 through which rod 67 extends, a key 73 secured to rod 67 permitting movement of the block along the rod, but preventing rotation thereon.

Desirably, a set screw 74 is provided to retain the block 69 in desired position along the rod.

'I'he other end of the block 69 desirably is bifurcated, defining a pair of spaced parallel legs 75 between which the guide arm 68 is positioned. Secured to the upper end 76 of the arm 68 as by screws 77 and extending at right angles thereto, is a bracket 78 which has an opening near its free end through which extendsl a screw 79 threaded into a correspondingly threaded opening 81 in block 69.

Axed to the screw 79 as by set screws 82 and straddling the bracket 78 is a pair of collars 83. Thus, upon rotation of the screw 79 by its knob 84, the guide arm 68 may be raised or lowered as desired so that its lower end 85 will be spaced a predetermined distance from conveyor belt 34.

Positioned immediately to the rear of the guide arms 68 is -a pair of pull rollers 87 (FIGS. 1 and 2) mounted on vertically aligned horizontal shafts and which serve successively to advance the box blanks to the folding unit 2l.

Referring to FIGS. l and 14, for exa. sple, the folding unit comprises a conveyor 90 including a pair of elongated parallel bars or rails 91, each ofthe ends of which at the inlet 92 of the conveyor having an inwardly ex- Itending shaft 93 (FIG. 2) on which a pulley 94 is mounted. Each 'of the ends of bars 91 at the outlet end 95 of the conveyor has a plate 96 secured thereto as by screws 97, said plate mounting inwardly extending

shafts

98 and 99, each mounting a

pulley

101, 102, the horizontal axis of shafts 93 and 99 being in substantially the same plane.

Each of the pairs of

pulleys

94 and 102 carries an endless conveyor belt 105, the upper runs 106 of which are supported by idler rollers 107 also mounted on bars 91 (FIG. l4).

Extending parallel to bars 91 are parallel bars 108 which extend in a plane above that of bars 91 and above and along the inner edges 109 of conveyor belts 105,

the bars 108 being supported by upright supports 111 suitably mounted so that they are vertically movable.

As shown in FIG. 14, each of the bars 118 has a horizontal elongated plate 112 extending laterally outward from the upper edge thereof, the free edge of each of said plates carrying a depending skirt 113, the lower edge 114 of which is slightly above the plane of the upper run 106 of conveyor belt 105.

Each of the bars 118 has a plurality of rollers 114 mounted on the outer surface thereof and adapted to urge the box blank 23 against the conveyor belts 105 in the manner hereinafter described.

The belts in conjunction with the rollers 114 thus serve asa conveyor successively to advance the open box blanks 23 as they are fed to the inlet 92 of the conveyor.

Positioned laterally of the inlet 92 of the conveyor is a glue roller 116 (FIG. 4) adapted to be vertically aligned with the connector ap 28'of the open box blank. -The glue roller illustratively rotates in a glue tank 117 and a pressure roller 118 is positioned directly over the glue roller to urge the connector ap thereagainst to ensure application of glue to the undersurface of such tlap.

Secured as by screws 121 (FIG. ll) to the inner sides of each of thel ends 122 of the bars 108 is a plate 123 I which protrudesbeyond such ends 122. Secured as by screws 124 to the protruding ends of each of the plates 123 is a block 125, the undersurface of which is bevelled as at 126 (FIG. 15).

Aixed as by screws 127 to the bevelled surface of each of the blocks is the end of a rigid elongated strip 128 which extends longitudinally of the associated bars 108.

Each of the strips 128 is thus inclined, and each has a plurality of stud shafts 131 (FIG. 18) rising therefrom and inclined outwardly, said shafts being longitudinally aligned and each carrying a disc 132 rotatably mounted thereon. v

As shown in FIG. 18, the -top and bottom peripheries of each of the discs 132 are bevelled as at 133, the angle of the bevel being such that the undersurface 134 of the outer edge of the disc will be in substantially a horizontal plane, with such outer edge extending slightly beyond the outer edge 135 of the associated conveyor belt 105.

Although any number of discs may be provided, two are desired and illustratively three are provided on each of the strips 128, the discs on the strips 128 being transversely aligned as shown in FIG. 1l.

Means are provided to fold the end panels A and D of the box blank inwardly as the blanks are advanced by the conveyor belts 105. To this end, as shown in FIG. l, a pair of

folding belts

138, 139 is associated respectively with the conveyor 90 on each side thereof. Each of the belts rides around a pair of

main pulleys

141 and 101, the pulley 141 being mounted on a shaft 142 extending laterally outward from `the bar 91 between the inlet 92 and the discs 132 (FIG. 1) and the pulley 101, as previously described, being mounted on shaft 98 extending laterally outward from plate 96 above pulley 102 as is shown in FIG. 2.

The upper run 145 of each of the

belts

138, 139 extends from the pulleys 141 over

rollers

146, 146 which are inclined upwardly, then against cone rollers 147, 147', the periphery of each of which is inclined inwardly as shown in FIG. 17, then beneath horizontal rollers 148, 148' (FIG. 17) which thus completes the twisting

vof belts

138, 138 through angles of 180 degrees so that they are horizontal. The belts then ride around pulley 101; between vertical rollers 151 which twist the belt 90 degrees Ito vertical position, then over inclined rollers 152, 152' and beneath and around the pulley 141.

As such folding belts are well known in the art, no further description thereof is deemed necessary.

In order to have the panel A of the box blank `23 fold inwardly prior to panel D in the manner hereinafter to be described, -the cone roller 147 associated with belt 138 is in advance of the cone roller 147 as shown in FIG. 17.

Means are provided to soften the creased folded edges 154 (FIG. 13) of the box blanks 23 so that the box blank may thereafter be squared in any suitable manner, such as by equipment of the type shown in patent application Serial No. 620,841, tiled November 7, 1956, and also to determine the gap between adjacent foldedover edges ofthe box blank. j

To this end, as shown in FIGS. 1 and 2, a plurality of :icsljzustable rollers 155 is provided located after the discs The rollers are suitably mounted on the bars 91 on vertical longitudinally aligned stud shafts so that their inner periphery will be engaged by the folded edges 154 of the box blanks as they are advanced.

Operation In the operation of the equipment the guides 53 (FIGS. -8) with the fins 65, are spaced along the support 52 so that the open box blanks may fit between the fins 65 with but little clearance and the other guide 53, one or more of which may be provided, depending upon the length of the open box blank, is spaced between the outer guides 53 and all the set screws 6l are tightened.

The hand wheel 48 is rotated to position the guides 53 so that when a stack S of open box blanks (FIG. 5) is positioned on the conveyor belt 34 between the outer guides 53, the trailing edges 64 of the blanks will rest on the rollers 63 of the guides and the leading edges 64 of the blanks will rest against the inclined portions 68 of the gauges 68 as shown in FIG. 5.

The blocks 69 carrying the gauges 68 are positioned along the rod 67 so that they will be located between the side edges of the box blanks to be fed and are locked in position by turning screws 74.

The gauges 68 are then lowered by turning screws 79 so that the lower edges 85 of the gauges are spaced from the upper run 35 of belt 34 riding around

rollers

32, 33 by a distance just slightly greater than the thickness of the box blank to be fed so that but a single box blank at a time may pass thereunder, the blank immediately thereabove being restrained by the gauge 68.

Suction is applied to the chamber 37 and the conveyor belt 34, and the pull rollers 87, the

conveyors

34 and 90 and

folding belts

138, 139 are actuated.

As a result of the suction applied to the chamber 37, the leading portion of the lowermost box blank-23 (FIG. 5) will be securely retained against the conveyor belt 34 by reason of suction applied through the perforations thereof.

As the'upper run 35 of conveyor belt 34 moves to the left, the leading edge 64 of the lowermost blank 23' will be advanced beneath the lower edges of the gauges 68 and between the nip of the pull rollers 87 which are driven to advance the box blanks in a forward direction.

As the box blank is retained in fixed position by the suction belt 34 and then by the pressure of the pull roller 87, it will remain substantially square and will not skew.

Referring to FIG. 5, so long as the trailing edge of the lowermost box blank 23 has not passed beneath the gauge 68, the box blank 23 immediately thereabove cannot be advanced. However, as soon as such trailing edge has passed the front gauge 68, then by reason of the suction imparted through the conveyor belt 34, the leading edge 64 of the next box blank 23" will be moved downwardly against the belt and be free to be advanced thereby past the front gauge 68. As the leading edges 64' of the box blanks 23 are engaged by said pull rollers which are driven at a higher rate of speed than the drive of the conveyor 34, the successive box blanks will be spaced from each other.

As the leading edge of each box blank is advanced past the pull rollers, they will be moved between the upper run 106 of the endless belts 105 and the idler rollers 114 thereabove of conveyor 90, as is clearly shown in FIG. 2. Since the upper bars 108 have been vertically adjusted so that the rollers thereon will effectively press the box blanks 23 against the conveyor belts 105, such box blanks will be securely gripped for advance by said belts 105.

As the box blank 23 is advanced in the above manner, the connector tlap 28 thereof will be moved between the glue roller 116 and pressure roller 118, which in conventional manner will apply a coating of glue to the undersurface of such ap. With continued advance of the box blanks 23 by the conveyor 90, the end panels A and D of the box blank 23, which extend outwardly beyond the skirts 113 (FIG. 14), will be moved into juxtaposition l to the

folding belts

138 and 139.

Referring to FIGS. l, 2 and 14, the

folding belts

138, 139 due to their incline will cause thepanels A and D to fold upwardly about their

score lines

24, 26. As the cone roller 147 (FIGS. 1 and 11) is in advance of the cone roller 147', the panel A will be folded inwardly by the belt 138 at a faster rate than the panel D (FIG. 15).

When the leading edge 64 of the box blank 23 is advanced past the cone roller 147, since the blank is beneath the bars 108 it will be guided beneath the discs 132 and the undersurface 134 of the discs 132 will press the portions of panels A and D inwardly of the score lines 24, 26 against the conveyor belts 105.

As the conveyor belts 10S are advancing and as the box blanks 23 are urged thereaginst by the discs 132, the discs will rotate so that the forward movement of the box blanks 23 will not be in any way restrained. As a result, the box blank will be advanced without skewing.

With further advance of the box blanks 23, the folding belt 138 (FIG. 17) will have been dellected by the cone roller 147 to bend the panel A inwardly past vertical position and the folding belt 13 9 Will have been de# llected by the cone roller 147' to bend the panel D to substantially vertical position.

As the outer peripheries of the discs are substantially aligned with the score lines 24, 26 between panels A, B andC, D, as shown in FIG. 14, the transverse distance between

such score lines

24, 26 will be maintained at a desired amount based on the pre-set transverse spacing between the bars 108.

With the further advance of the blanks, the upper run 145 of the folding belt 138 will iirst move the panel A to substantially horizontal position and thereafter the upper run 145 of the folding belt 139 will move the panel D to substantially horizontal position so that the glued connector ap 28 of panel A will be engaged by the corresponding portion of panel D adjacent its edge 29 as shown in FIG. 10.

Thereafter, the upper runs 145 of

folding belts

138, 139 will be moved to horizontal position by

rollers

148, 148 to press the folded box blank against belts 105 to advance the folded box blanks past the rollers 155 on each side of the box blank. The rollers reacting against the respective folded

edges

24, 26 of the box blanks will determine the gap between the folded-over edges of the box blank and also crush and soften such edges so that after the box blank is discharged from the outlet 95 of the conveyor 90 of the folding unit, since the glue applied to the connector flap 28 is of the slow setting type, the box blank may readily be squared as by the equipment shown and described in patent application, Serial No. 620,841, led November 7, 1956.

With the feeding equipment above described, as the stack of box blanks rest on the suction conveyor belt, the

entire area of the bottommost box blank in the stack will be retained by the suction against such belt, overcoming any warpage that may exist in such blank. Consequently, the bottommost blank will be dependably advanced beneath the stop 85 without likelihood of skewing or jamming. l

In addition, as it is the suction that advances the box blank, regardless of the configuration of the edges thereof, dependable advance will be effected.

As many changes could be made in the above construction, and many apparently widely different embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. v

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. Equipment for successively discharging the bottommost blank of corrugated board from a stack of such blanks in which the blanks are in substantially horizontal position, comprising a perforated conveyo'r belt positioned in substantially a horizontal plane on which at least a portion of the bottom of said stack adjacent its leading edge rests, means to advance said belt, stop means dening the outlet of said conveyor belt, positioned above the latter and suiciently spaced therefrom to permit passage thereunder of only a single blank at a time, means to create a. suction through the perforations in said conveyor belt to react against a substantial portion of the undersurface of the bottommost blank of the stack to advance such blank, said suction also being provided at least directly adjacent said stop means to react against the leading portion of the blank from its leading edge, whereby the leading portion of the blank including its leading edge will be dependably moved downwardly and securely retained by the suction against the conveyor belt for advance beneath said stop means.

2. The combination set forth in claim 1 in which a pair of spaced parallel rollers is provided mounting said perforated conveyorbelt, said stop means comprises a gauge arm, means to support said gauge arm with the lower end thereof substantially vertically aligned with the portion of the conveyor belt riding over one of said rollers, the lower edge of said gauge arm being spaced from said belt by a distance slightly greater than the thickness of the box blank.

3. The combination set fo'rth in claim 2 in which said gauge arm is an elongated rectangular bar having its lower portion inclined away from the conveyor belt and means are provided to adjust the vertical-position of said gauge arm. y

4. The combination set forth in claim l in which a support for the trailing edge of said stack is provided extending transversely across the conveyor belt and longitudinally spaced from said stop means, means to effect relative movement between said support and said stop means, said support and said stop means being spaced so that `with the leading edge o'f the stack abutting against the stop means, the trailing edge of the stack will rest on the support with the trailing portions of the blanks in the stack spaced from said conveyor belt.

5. The combination set forth in claim 4 in which a plurality of back stops are slidably mounted on the supl port, means to retain the back stops in desired position -on the support and a roller is rotatably mounted on said back stops on an 'axis extending parallel to the direction of movement of said conveyor.

6. The combination set forth in claim 4 in which a plurality of back stops are slidably mounted on the support, means to retain the back stops in desired position on the support, each of said back stops comprising a pair of spaced parallel flanges and a plurality of rows of rollers rotatably mounted between said anges on axes extending at right angles thereto, the outer peripheries of said rollers extending beyond said flanges.

7. The combination set forth in claim 4 in which said support comprises roller means on which the trailing edge of the stack will rest and a pair of spaced tins are carried by said support to serve as a guide for the box blanks.

References Cited in the tile of this patent UNITED STATES PATENTS Coakley Oct. 18, 1960