US3409148A

US3409148A - Stacking device

Info

Publication number: US3409148A
Application number: US516421A
Authority: US
Inventors: Albert F Shields
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-12-27
Filing date: 1965-12-27
Publication date: 1968-11-05
Anticipated expiration: 1985-11-05
Also published as: NL6616408A; FR1506706A; GB1154392A; DE1295991B; GB1154391A; DE1786420B1; JPS496583B1

Description

Nov. 5, 1968 A. F. SHIELDS STACKING DEVICE 4 Sheets-Sheet 1 Filed Deo. 27, 1965 Nov. s, 196s A. F. SHIELDS 3,409,148

STACKING DEVICE Filed D60. 27. 1965 I 4 Sheets-Sheet 2 Nov. 5, 1968 A. F. SHIELDS STACKING DEVICE Filed Dec. 27, 1965 4 Sheets-Sheet 3 IFJ .E

Nov. 5, 1968 Filed Dec. 27, 1965 O 0 D O O O A.F.SPHELDS STACKING DEVICE 4 Sheets-Sheet 4 United States Patent O 3,409,148 STACKING DEVICE Albert F. Shields, 43 Exeter St., Forest Hills, N.Y. 11375 Filed Dec. 27, 1965, Ser. No. 516,421 13 Claims. (Cl. 214-6) ABSTRACT F THE DISCLOSURE Boxfolding, stacking' and straightening 'apparatus is provided with independently .adjustable upper conveyor belts to positively control feeding of folded boxes to a point along the feed path as close to the stacking section as practical |without interfering with entry of folded boxes to the bottom of a rising stack. Upper conveyor belts are selectively pivoted between two discrete positions in one of which the upper belt remains in4 engagement with lthe folded box until a point very close to the stacking section to retain positive control of relatively short boxes. In the other position the upper belt releases'engagement with the folded box at a point considerably to the rear of the stacking section so that the liftinlg of relatively long boxes in the stacking section will not be impeded by the horizontal conveyor means. Boxes of irregular shape at the leading edge Iare handled without skewing by placing different sections of the'upper belt in different positions. The barrier in the stacking section to arrest forward movement'of the blanks is stepped in a forward direction and is provided with a transition region including Ia roller 'rotating on a horizontal axis so as to lift the leading edges of the folded boxes and in this way minimize the weight applied to folded boxes as they enter the stacking section. Periodically, a delivery device engages the upper end of the stack to remove a pile of boxes therefrom. Such delivery'device is provided with independently adjustable stop means for a plurality of vertically movable pusher arms so thatvthe irregular shape of the folded box at the top of the stack will not prevent the delivery of a pile having a predetermined number of folded boxes therein. At the end of .a run, the last few folded boxes are raised to la position at the top of the barrierby a manually operated lift means to clearthe top of the barrier means and be removed by the pusher arms.

The instant invention relates to paper box making machinery in general and in particular relates to an improved construction of the type of apparatus disclosed in my United States Patent 3,203,561 issued Aug. 31, 1965, and entitled, Lift Cam for Stacking Device.

Broadly speaking, devices of the type under consideration .include feed belts 'which receive blanks issuing from a folding machine as folded tubular boxes and convey these blanks ,along a generally horizontal feed path to a point where the side edges of the blanks are engaged by lifting screws and the forward movement of the blanks is arrested by engagement of the leading edges with a vertically extending barrier positioned forward of the lifting screws. The lifting screws raise the blanks above the feed path to forml .a bottom fed stack and a pusher means, operated in time relationship 'with the lifting screws, moves horizontally from the rear into engagement lwith the top portion "of the stack to` remove a pile containing a predetermined number of blanks.

As'hereinafter described' in detail, the instant invention provides improved horizontal conveyor means which include upper belt sections that are selectively .adjustable so that these belt sections will n-ot cause interference with blanks after they have been engaged by the lifting screws. More particularly, in the case of relatively short blanks,

lCe

it is necessary to provide driving power by the conveyor belts to a point very close to the lifting screws. However, if driving power to this same point is maintained when relatively long blanks are being handled, the rear of these long blanks will be held down by the conveyor means while the lifting screws are raising the front portion of these long blanks. If these blanks are extremely long, the lifting belts will raise the blank a considerable distance prior to release of the blank by the conveyor belt and under these circumstances the blanks Iwill be damaged.

In order to alleviate this condition the upper conveyor belt means of the instant invention is selectively positionable so that it positively drives short blanks to la point very close to the lifting belts. When relatively long blanks are being handled the upper feed belt means is repositioned so that it ceases to positively drive the relatively long blank prior to the time that this blank is lifted to any great extent by the lifting sorews.

This upper belt means is hereinafter shown as comprising two independently adjustable sections so as to facilitate the handling of die cut boxes in which one portion of the trailing edge extends considerably to the rear of another portion of the trailing edge. Under the latter circumstances the more rearwardly extending trailing edge portion is released by the upper conveyor belt means at a point considerably to the rear of the point at which the less rearwardly extending trailing edge portion of the blank is released by the upper conveyor belt means. This assures a positive conveyor movement of the blank without cocking until such time as the blank is well under the control of the lifting screws.

As previously noted, in the device under consideration an underfed stack is formed by lifting screws positioned at the sides of the stack near the rear thereof. The threads of the lifting screws separate and positively support the blanks at the rear of the stack but at the forward end of the stack the lower blanks support the upper blanks. Under certain operating conditions, principally when the stack is permitted to become relatively high prior to removal of the top portion, the stack becomes relatively heavy and, unless appropriate measures are taken, a considerable downward force acts upon the lo-wer blanks in the stack land may interfere with the entry of new blanks at the bottom of the stack. In order to overcome this A condition the instant invention provides .a vertical barrier means having a forwardly stepped portion at the upper end thereof with the upper and lower portion-s of the barrier means being connected by a transition means so constructed that the bottom blanks in the stack are not required to support the Iweight of the blanks positioned at the forwardly stepped upper end of the barrier means.

In the form of the instant invention to be hereinafter described the transition region is formed by a peripheral portion of a wheel means which is positioned and rotated so that the peripheral portion moves upwardly and forward. Once the leading edge of a blank is engaged by the wheel means this blank is lifted away from the blanks below the transition region so that the weight thereof no longer acts on the blanks entering the stack from below.

In order to assure that each of the piles removed from the top of the stack contains the same number of blanks it is essential that engagement between the pusher means and the top of the stack be accurately controlled. It has been found that with a single pusher means member engaging the top of the stack, quite often the desired results are not achieved. In the case of boxes having glue joints, it is believed that the last mentioned undesirable effect results from the fact that a glue joint, even though` crushed, presents a thickness greater than the thickness of a single sheet of uncrushed board, with this additional thickness being a variable quantity within a given run.

It has been found that superior results are obtained by constructing a pusher comprised of side-by-side members which are independently adjustable to their lowermost, or stack engaging, positions. As will hereinafter be shown, the adjusting means is so constructed and positioned that it may be operated while the pusher means is in operation thereby facilitating the making of adjustments required to compensate for unpredictable variations.

Accordingly, a primary object of the instant invention is to provide a novel construction for the stacking section of box making apparatus.

Another object is to provide apparatus of this type having novel horizontal conveyor means.

Still another object is to provide apparatus of this type having novel means for limiting forward movement of the blanks.

A further object is to provide apparatus of this type having novel means for lifting the stack to delivery position at a time after the last blank is fed into the stacking device.

A still further object is to provide apparatus of this type with novel pusher means to increase accuracy of the count in piles of blanks being delivered.

These as well as other objects of this invention will become readily apparent after reading the following description of the accompanying drawings in which:

FIGURE l is a longitudinal cross-section taken through line 1-1 of FIGURE 2 looking in the direction of arrows 1--1 and illustrating apparatus constructed in accordance with the teachings of the instant invention.

FIGURE 2 is a fragmentary plan view taken through line 2-2 of FIGURE 1.

FIGURE 3 is an enlarged fragmentary plan view showing a die cut blank at a time when its forward motion has been arrested in the stacking region.

FIGURE 4 is a fragmentary cross-section taken through line 4-4 of FIGURE 2 looking in direction of arrows 4-4.

FIGURE 5 is an enlarged fragmentary side elevation illustrating the relationship between selected elements at the front barrier.

FIGURE 6 is a front elevation looking in the direction of arrows 6 6 of FIGURE 1 and showing one section of the pusher means for removing piles of blanks from the stacking section.-

FIGURE 6A is a side elevation of the pusher means looking in the direction of arrows 6A-6A of FIGURE 6.

Now referring to the gures and more particularly to FIGURE 1. The portions of the box making apparatus incorporating the novel features of the instant invention include conveyor means 11 which receives box blanks in folded tubular form from a folding machine (not shown) positioned to the left of FIGURE l. Conveyor means 11 moves the blanks forward along a generally horizontal feed path and delivers these blanks to lift cam operated roller 99 and lift screws 12, 13. The threads of screw means 12, 13 engage the edges of the blanks to impart upward movement to such blanks to form stack 14 which is fed from below. Forward movement of the blanks is arrested by barrier means 15, shown enlarged in FIGURE 5. Delivery means 16, positioned above stack 14, periodically engages the upper portion of stack 14 to remove a pile 17 of blanks from the top of stack 14 and deliver pile 17 in a forward direction on to the rollers of conveyor table 18.

Conveyor means 11 is, in essence, 3 pairs of continuous belt devices driven at the same speed with lower belt device and 2 belts 23 and 23a, sections 19, 23, 23a

positioned below the feed path for entering blanks andupper

belt device sections

20, 21, 22 positioned above the feed path. The lower flight of belt 20 and the upper flight of belt 19 always confront one another and with belts 21, 22 in the positions shown in FIGURE 4, the lower tlights thereof also confront the upper flights of belts 23 and 23a, respectively. Belts 21 and 2,3 are mating belts which are located on one side of the machine while belts 22 and 23a are mating belts which perform the same function as belts 21, 23 on the other side of conveyor means 11.

Since details of the chains and sprockets connecting the power source to the elements of the apparatus for operation in timed coordination form no part of the instant invention and are within the knowledge of those skilled in the art, descriptions thereof are not contained herein.

Conveyor belt means 26, positioned forward of lifting screws 12, 13, is provided with an upper generally horizontal flight positioned slightly above the upper flight of belt 19. Belt means 26 consists of a plurality of narrow parallel sections all driven in a clockwise direction with respect to FIGURE 1 by pulleys and associated chain and sprocket means. The front edges of blanks fed by conveyor means 11 passed lifting screws 12, 13 are initially supported by belt means 26 which guides the forward edges of the blanks to the lower end of barrier means 15. Such guidance is assured by slat 27 positioned just below the lower end of barrier means 15 and supports the upper tlights of belt means 26.

Lifting screws 12, 13 provide a positive upward movement to the blanks in stack 14 in the vicinity of the rear portion of stack 14. At the forward portion of stack 14 the leading edge of a blank newly arrived at the bottom of stack 14 forces blanks thereabove in an upward direction. Hold down

elements

28, 29 extending forwardly from hinge means 30 apply downward forces to stack 14 and pile 17 to prevent opening of the glue joints of the folded tubular boxes prior to setting of the glue. Pusher means portion 32 of delivery means 16 periodically engages the top portion of stack 14 and moves pile 17 in a forward direction.

At the end of a run of a given order of boxes, after the last blank entering conveyor means 11 has been fed to the bottom of stack 14 it is necessary to provide additional means to raise the forward end of stack 14 above front gage 32 at the upper end of barrier means 15. This is accomplished by manually operable lifting means (FIGURE 5) to be hereinafter described. The description of the apparatus illustrated in the drawings has, up to this point, been relatively brief. For a more detailed description of the basic elements of the illustrated apparatus reference is made to my aforesaid U.S. Patent 3,203,561 and my U.S. Patent Numbers 3,063,- 577 and 2,963,177, as well as any additional publications and/or patent applications referred to in the aforesaid patents. Accordingly, the following description will, for the most part, be limited to those elements which per se, or in combination with other elements, constitute the novel features of the instant invention.

Adjustable sections of conveyor means 11 Belt 20, though not necessarily positioned on the longitudinal cent-er line of the apparatus, is nevertheless referred to as the center belt. It is noted that center belt 20 at its forward end is supported by wheel 41 mounted to shaft 42 with a considerable space existing between the forward end of belt 20 and lift screws 12, 13.

Each of the belts 21, 22 is of identical size and shape and is supported by identical members so that for the sake of brevity, but without sacrificing clarity, only a description of the mounting for belt 22 will be given. As best seen in FIGURE 4, belt 22 is guided along a path defined by wheels 43, 44, 45. The shafts to which wheels 44, 45 are mounted extend from movable frame member 46 pivotally mounted with shaft 42 as a pivot center. Frame member 46 is operable from its lowered position shown in the solid line in FIGURE 4 to a raised position shown in phantom in FIGURE 4. Spring 47 and stop means 48 engage frame 46 to hold the latter in its lowered and raised positions, respectively.

It is noted that with frame 46 in its lowered position, belt 22 extends forward of belt 20 (as seen in the dashed lines of FIGURE l) to a position in line with slapper bar 49 which is oscillated longitudinally with respect to the box feed path and is positioned so as to engage the trailing edges of blanks being raised by lifting screws 12, 13. When frame number 46 is in its raised position belt 22 extendsno further forward than belt 20.

The adjustments for belts 21, 22 make possible the utilization of the apparat-us illustrated for stacking both very short and very long blanks. More particularly, if frame numbers 46 were in their lowered positions of FIG- URE 4 at a time when relatively long blanks were being processed, lifting screws 12, 13 would impart a considerable amount of upward movement to a blank prior to release of such blanks by belts 21, 22 in that in the lowered position of frame number 46 belts 21, 22 extend to a position extremely close to lifting screws 12, 13. Because of this relatively short distance between belts 21, 22 and screws 12, 13 and lift imparted to the blank by screws 12, 13 cause deflection of the blank to the point where it would be damaged. Hence, for relatively long blanks each of the frame members 46 must be moved toits raised position where the distance between belts 21, 22 and screws 12, 13 is relatively great so that the angle yof deflection caused by the lifting of the relatively long blank while it is still engaged by belts 21, 22 will not damage this blank. Naturally, when a relatively short blank is being processed if frame 46 is in its raised position conveyor means 11 will cease exerting a positive drive force in the forward direction possibly before such short blank is fully engaged by lifting screws 12, 13 and certainly before such blank is in the vicinity of barrier means 15. Thus, for relatively short blanks it is necessary that the positive driving force by conveyor means 11 be applied to a point very close to lifting screws 12, 13.

Movable belts 21, 22 are provided with independent adjustments in order to accommodate the handling of die cut blanks having trailing edges in which one side extends considerably more to the rear than the other side, such as blank 51 (FIGURE 3) with portion 51a extending considenably more to the rear than portions 51b. If both of the belts 21, 22 could only be adjusted simultaneously, the only adjustment that would not damage blank 51 would be to raise both belts 21, 22. However, if this is done a positive driving force ceases to act on portion 51b at a time considerably in advance of the time when positive a driving force ceases to operate on portion 51a :and because of this blank 51 would cock and cause the apparatus to malfunction.

Thus, instead of adjusting both belts 21, 22 to their upward positions, as seen in FIGURE 3, belt 22 is adjusted to its upward position while belt 21 is in its lowered position. With such adjustment the release of portion 51b by belt 21 occurs at approximately the same time as the release of portion 51a by belt 22 so that a positive drive exerted -uniformly on both sides of blank 51 is eifective to a point where blank 51 is well under the control of lifting screws 12, 13 and the forward movement of blank 51 is arrested by barrier 15.

Front barrier means Front barrier means 1S, shown most clearly in FIG- URE S, provides a vertically extending wall with a lower portion 15a and an upper portion 15b forwardly offset from portion 15a. The step between portions 15a, 15b is gradual and takes place at a transition kregion formed by a peripheral portion 62 of roller means 63 which is con- -tinuously rotated by motor 64 in the direction indicated by arrow A in YFIGURE 5 about shaft 65 as a center. Thus, peripheral portion 62 provides an upwardly and forwardly sloping surface moving upwardly.

It is noted that peripheral portion 62 is illustrated :as extending for less than 90 and that lowerportion 15a is tangent to peripheral portion 62 with the upper end to portion 15a terminating at the tangent point. While this contiguration has been found to produce superior results when folder tubular boxes of corrugated paper board are being handled, it is recognized that the angular ex- CTI 6 tent of peripheral portion :and its position relative to barrier portions 15a, 15b may be varied when handling different articles or to achieve different results in a particular area.

As each blank enters stack 14, being driven forward by momentum and the action of belt means 26, it'wedges its way between belt means 26 and the bottom stack 14. Lower barrier portion 15a arrests forward 'movement of the newly entering blank by engaging its leading edge. As additional blanks enter stack 14 from below the forward portions thereof are wedged into position at the bottom of stack 14 forcing the forward portions of blanks thereabove to move upwardly at essentially the same rate as lifting screws 12, 13 impart rupward movement to the rear portions of these blanks.. When the leading edge of a blank moving upwardly in 'stack 14 reaches the top of lower barrier portion 15a, this leading edge is engaged by the knurled periphery of roller means 63 at its peripheral portion 62. The upward and forward movement of peripheral portion `62 draws the blank in engagement therewith away from the portion of stack 14 below this blank thereby removing the weight of this blank and all blanks thereabove from the portion of stack 14 below this blank.

It is noted that slapper bar 49, which is vibrated generally parallel to the blank feed path as indicated by line V in FIGURE 5, imparts hammerlike blows to the trailing edges of the blanks in stack 14 directed towards barrier means 15 to effect a straightening action to these blanks as fully described in my aforesaid U.S. Patent No. 3,203,561.

For purposes of describing the instant invention it is sufficient to note that the forward surface of slapper bar 49 is provided with a forward surface having generally vertical sections 49a, 49b joined by forwardly sloping transition section 66. Upper section 49b is positioned forward of lower section 49a. It is noted that transition section 66 essentially complements peripheral portion 62 so that as the leading edge of a blank is drawn upwardly and forwardly by peripheral portion l62 the trailing edge of this blank is in engagement with the forwardly sloping transition section 66, and that at the time that the leading edge of this blan-k engages upper section 15b the upper section -49b of slapper bar 49 will be effective to continue with the straightening action.

Manually operated stack lifting means At the end of a run there are no additional blanks entering stack 14 to lift the forward portion of the bottom blank in the stack. Thus, even though lifting screws 12, 13 continue to lift the rear portion of the entire stack to delivery position above the upper end of front barrier portion 15b, delivery cannot be effected. Accordingly, the instant invention provides manually operated lift means indicated generally by reference to mode 70 in FIG- URE 5.

As previously noted, conveyor belt means 26 is comprised of a plurality of narrow belts positioned parallel to one another and spaced transversely with respect to the generally horizontal feed path for the blanks. Lift means 70 includes transversely extending pivotally mounted support rod 71 to which a plurality of members 72 are mounted. Each of the members 72 is of generally U-shaped with one arm 72a considerably longer than the other arm 72b. Wheel 73 is rotatably mounted at the free end of arm 72a while the free end of arm 72b is xedly secured to rod 71. Arms 72 are transversely spaced along rod 71 so that each of the rollers 73 is positioned in alignment with a different space between the sections forming belt means 26. L-shaped crank 74 is ixedly secured at one of its ends to rod 71 while the other end of crank 74 is provided with transversely extending handle 75.

When belt means 26 is not supporting any blanks the upper flight thereof is essentially aligned with the most upwardly extending points of rollers 73 in the lowered position for lift means 70, established by the engagement of crank 74 with stop 76. As a stack of blank 14 is being formed, belt means 26 begins to sag so that the front end of stack 14 is nowsupportedby rollersv73 thereby relieving belt means 26` from supporting the weight of stack 14. y

After the last blank in a particular run has its forward movement arrested by barrier means 15, cran-k 74 is manually operated in a clockwise direction about rod 71 as a center thereby raising roller 73 'to thephantom position of FIGURE 5. The raised position for lift means 70 is established by engagement of arms 72 with bar 27. In this raised position of lift means 70 the bottommost blank in the stack 14 is positioned with-its forward end above the upper end of upper barrier section 15b. Thus, when lifting screws 12, 13 lift the rear end of the bottommost blank in stack 14 to a position for engagement by pusher means 32y the remaining portionY of stack 14 will be delivered by pusher 32 to conveyor 18.

i Pusher means The driving and stabilizing means 79 (FIGURE 1) for pusher means 32 forms no part of the instant invention so that a detailed description thereof will not be given herein except to note that such mechanism is described in detail in my patents hereinbefore noted.

While pusher means 32 consists of two

identical sections

32a, 32a only one of these sections is illustrated (see FIGURES 6 and 6A). Both pusher means

sections

32a, 32a occupy positions in a single plane perpendicular to the blank feed path and are usually positioned on opposite sides of this feed path. As will hereinafter become apparent, the transverse positions of the pusher means sections are independently adjustable as are the lowermost positions thereof.

Pusher means 32a is connected to the chains 79a, 79b of driving means 79 by vertically spaced laterally extending frame rails 83a, 83h whose opposite ends are connected to different vertical tie rods `83, 83 connected directly to link of chains 79a, 79b.

Vertically extending guide bar 84 is slidably mounted to rails 83a, 83h by

gibs

82a, 82b, respectively. Clamp means `82C associated with gib 82b clamps vertical guide bar 84 in its adjusted position along the lengths of rails 83a, 83b.

At a point below gib 82b bolts 85a secure lateral guide block 86 to bar 84, adjusting rod 92, threaded at its upper end extends downward through clearance aperture 91a in block 86. The lower end of rod 92 is aixed to stop plate 87 while knurled adjusting nut 93 is threadably mounted to rod 92 above block 86. Rod 89 extends downward from block 86 through clearance aperture 91 in plate 87 to stabilize plate 87 against rotation as nut 93 is rotated. Coiled compression spring 92a mounted to rod 92 biases plate 87 downward to its adjusted position established by the position of nut 93 along rod 92. The lower end of guide bar 84 extends downwardly into the upper end of tubular pusher 85 w-hich, as seen in FIGURE 1, is the portion of pusher means section 32a which engages the rear of stack 14 to remove pile 17 therefrom. Pusher 85 is biased downwardly by gravity with its downward movement being limited by ear 86 which extends laterally from pusher 85 to engage the upper surface of adjustable platelike stop member 87.

Wheels

98, 99 mounted to bar 84 are positioned to engage the front :and back inner surfaces, respectively, of pusher 85 and thereby reduce friction acting to impede upward move-ment of pusher 85 relative to bar 84 during delivery of pile 17 from the top of stack 14. In this connection it is noted that wheel 99 is positioned above wheel 98. Pusher means section 32a is intended to be adjusted while delivery means 16 is in operation and preferably just prior to engagement of pusher 85 with the rear of stack 14. By turning nut 93 the position of stop plate 87 is -adjusted vertically with respect to bar 84 and rails 83a, 83h thereby establishing the lowermost position for pusher 85. This lowermost position for pusher 85 is the position it will occupy at the moment of engagement with the rear of stack 14. During the interval when pusher is delivering pile 17, lifting screws 12, 13 continue to raise stack 14 and in so doing the portion of stack 14 below pusher 85 causes upward movement thereof with-this -movement being permitted by the telescoping relationship of vertical guide 84 `and tubular pusher 85. The position of adjusting nut 93 is such that it may be convenientljl reached by an operator so that the operator may observe the exact position of pusher 85 relative to ystack 14 at the moment of initial engagement with stack 14 and make necessary corrective adjustment of member 87 before the next cycle of pusher means 32.

The adjustment of'pusher means

section

32a, 32a are made independently of each other since different sizes of blanks and blanks contructed of different types of materials present panels which are differentially positioned with respect to each of the pusher means

sections

32a, 32a. It is essential that the pushers 85 of both

sections

32a, 32a be 4positioned to positively engage the lowermost blank vin pile 17 at the instant of initial engagement. If only one of the pushers 85 engages the bottommost blank in pile 17 this blank will skew and cause jamming of the apparatus.

Thus, it is seen that the instant invention provides an improved stacking Iand delivery device which includes novel yadjustable belt means for delivering blanks to a stacking section which includes novel rotatable wheel means constituting a transition section between upper and lower vertical barrier sections with the upper section being forwardly set wit-h respect to the bottom section. Also ineluded are novel manually operated means to lift the stack of blanks lat the forward end thereof to facilitate removal at the end of a run, and-novel takeoff means having a plurality of independently adjustable pusher means section.

Although there has been described a preferred embodiment of this novel invention, many variations and modifications will now be apparent to those skilled in the art. Therefore, this invention is to be limited, not by the specific disclosure herein, but only by the appending claims.

I claim:

1. In the combination of a machine for operating on box blanks and delivery apparatus adapted for use with said machine; said apparatus comprising a stacking means and a conveyor means extending between said machine and said stacking means; said conveyor means receiving blanks issuing from said mechanism and moving these blanks forward along a Igenerally horizontal feed path to said stacking means; said conveyor means including first and second sections, one above and the other below said feed path; said sections mounted in opposed relationship and lboth being positioned to engage blanks moving along said feed path and drive these blanks forward; the improvement comprising adjustable mounting means for selectively positionin-g said first section at a first and a second position while said second section remains in fixed longitudinal position along said feed path; when in said first position said first section after engaging a blank thereafter releasing this blank at a first point of said feed path; when in said second position said first section after engaging a blank thereafter releasing this blank at a second point of said feed path; said first Aand saidV second points being longitudinally spaced along said feed path with said second point positioned forward of said first point.

2. A combination as set forth in claim 1 in which said rst section includes first and second portions disposed on opposite sides of a longitudinal center line for said feed path; each of said portions mounted for independent adjustment to said first and said second positions.

3. A combination as set forth in claim 1 in which said first and said second sections are comprised of first and second continuous belt means, respectively; a greater length of said Afirst belt means bein-g directly opposed to said second section when said first section is in said second position than when said yfirst section is in said first position.

4. A combination as set forth in claim 3 in which the mounting means includes pivot means about which said rst section is bodily movable as a u-nit to said first and said second positions; said pivot means positioned in the vicinity of said first point; guide means for said first belt means including a member rotatable about said pivotal axis; said rfirst belt means inclluding a lower flight extending from said -rst point forward to said second point when said iirst section is in said second position.

5. In the combination of a machine for operating on box blanks and delivery apparatus adapted for use with said machine; said apparatus comprising a stacking means and a conveyor means extending between said machine and said stacking means; said conveyor means receiving blanks issuing from said mechanism and moving these blanks forward along a generally horizontal feed path to said stacking means; said stacking means including first m-eans for imparting upward movement to blanks as they enter said stacking means; said stacking means including a second means providing a barrier means positioned forward of said 4first means; said barrier means extending generally vertically above said feed path and positioned to engage leading edges of blanks moving along feed path to thereby arrest fonward movement of these blanks; the improvement comprising the construction of said barrier means with upper and lower surface portions, said upper and lower surface portions being stationary and rigid, said upper surface portion disposed at a location stepped forward of said lower surface portion.

`6. A combination as set forth in claim 5 in which the stacking means forms ya stack of blanks that is fed from the bottom; a delivery means which periodically removes the top portion of the stack from said stacking means; lifting means including a member engageable with the bottommost blank in the stack at a point forward of said lirst means, in the vicinity of said barrier means and to the rear thereof; said member normally stationary in a lowered position and being movable to a raised position to thereby lift the bottommost blank to a position where the delivery means removes such bottommost blank from said stacking means together with all those blanks in the stack above such bottommost blank.

7. A combination as set forth in claim 5 in which the stacking means forms a stack of blanks that is fed from the bottom; a delivery means which periodically removes the top portion of the stack; said delivery means including pusher means operated in timed relation with said first means, means for guiding movement of said pusher means in a raised path fwhile moving rearward and in a lowered path while moving forward; said pusher means when in said raised path being above the topmost blank in said stack and when in said lowered path engaging said top portion at the rear thereof and moving said top portion forward of said barrier means; said pusher means including a first pusher Iand a second pusher positioned side by side, means mounting said pushers for vertical movement independent of one another, first and second stop means for limiting downward movement of said first and second pushers, respectively, and means for ma-klng independent adjustments of said first and second stop means.

8. A combination as set forth in claim 9 including a slapper means oscillating generally parallel to said feed path and positioned rearward of said first means and engageable with said blanks at the trailing edges thereof as said blanks are being llifted by said first means; said slapper means having a forwardly and upwardly sloping section positioned to engage blanks that are in engagement with said transition section; said slapper mea-ns including additlonal sections positioned to engage blanks that are in engagement with said upper and said lower surface porlons.

9. A combination as set forth in claim 5 in which the barrier means also includes an rupwardly iand forwardly sloping transition section positioned between said rupper and said lower surface portions.

10. A combination as set forth in claim 9 in which there is a rotatable wheel means having a peripheral portion constituting said transition section.

11. A combination as set forth in claim 10 also including means imparting continuous rotation to said wheel means.

12. A combination as set forth in claim 11 further including means defining a rotational axis for said wheel means, said rotational axis positioned forward of said lower portion of said barrier means, said lower portion of said barrier means being tangent to said peripheral portion.

13. A combination as set forth in claim 12 in which said peripheral portion extends for no more than ninety degrees.

References Cited UNITED STATES PATENTS 1,454,924 5/ 1923 Halvorsen 214-6 1,819,841 8/1931 Hudson 214-6 1,957,318 5/1934 Bush 214-8.5 2,931,520 4/ 1960 Shields 214-6 2,963,177 12/1960 Shields 214-6 3,030,867 4/1962 Wright 214-6 3,063,577 12/1962 Shields 214-6 3,067,885 12/ 1962 Kohler 214-8.5 3,174,633 3/1965 Stevens 214-8.5

ALBERT J. MAKAY, Primary Examiner.