US 3331186 A
Description (OCR text may contain errors)
July 18, 1967 E. A. BRAUN HIGHSPEED CARTON TRANSFER MECHANISM 4 Sheets-Sheet 1 Filed 001;. 22, 1964 Wm Mm /NVENTOR ERIC A. BRAUN ATTORNEYS H mUTm July 18, 1967 E. A. BRAUN HIGHSPEED CARTON TRANSFER MECHANISM 4 Sheets-Sheet 2 Filed Oct. 22, 1964 F'IG.3
lNl/ENTOR ERIC A. BRAUN A T TORNE VS July 18, 1967 E. A. BRAUN HIGH-SPEED CARTON TRANSFER MECHANISM 4 Sheets-Sheet 3 Filed Oct. 22, 1964 INVENTOR FIG. 4-
ERIC A. BRAUN ATTORNEY July 18, 1967 E. A. BRAUN HIGH-SPEED CARTON TRANSFER MECHANISM 4 Sheets-Sheet 4 Filed Oct. 22, 1964 F IG. 6
INVENTOR ERIC A. BRAUN ATTORNEYS 3,331,186 Patented July 18, 1967 3,331,186 HIGH-SPEED CARTON TRANSFER MECHANISM Eric A. Braun, Farmington, Mich., assignor to Ex-Cell-O Corporation, Detroit, Mich., a corporation of Michigan Filed Oct. 22, 1964, Ser. No. 405,689 Claims. (Cl. 53-186) ABSTRACT OF THE DISCLOSURE A carton transfer mechanism having two pairs of opposed endless belts arranged vertically on pulleys such that the lower end pulleys are at substantially the same elevation while the upper end pulleys are at substantially different elevations to enable a tubular carton blank, positioned with its principal axis vertical, to be moved horizontally over the shorter pair of belts to initially abut one panel of the carton against the longer pair of belts. As the carton blank is contacted by the longer pair of belts it is conveyed downwardly a minimal distance for the opposed carton blank surface to be contacted by the shorter pair of belts and maintained under a slight pressure while conveyed downwardly onto a vertically positioned mandrel.
The present invention relates to an improved mechanism for feeding tubular carton blanks onto a mandrel.
Carton fabricating machines, of the type on which a transfer mechanism exemplary of the present invention is useful, are capable of performing all of the operations necessary to produce a filled and sealed carton from a flat folded blank. In such a machine, a flat folded blank is withdrawn from an appropriate magazine or stack of blanks by a feeding mechanism, erected into a tubular form and transferred onto an end forming mechanism, from whence it goes to the filler unit where the thus formed containers are then filled, closed and sealed.
One of the objects of the invention is to provide an improved high-speed transfer mechanism which has a minimum of component parts.
Another object of this invention is to provide transfer of the tubular carton blanks with a minimum of physical distortion to the carton blanks.
Another object of this invention is to provide positive control of the carton blank as it is being transferred from the loading mechanism to the mandrel of the end forming mechanism.
A further object of this invention is to provide a transfer mechanism of the type set forth which is of simple construction requiring a minimum of care and maintenance.
Other objects and advantages of the invention will be apparent upon reading the attached detailed description in connection with the accompanying drawing, in which:'
FIG. 1 is a side elevational view of an illustrative carton forming machine embodying the present invention;
FIG. 2 is a flattened tubular blank as supplied on the machine;
FIG. 2a is a perspective view of the squared-out tubular blank;
FIG. 2b is a perspective view of the squared-out tubular blank with the bottom end sealed;
FIG. 20 is a perspective view of the sealed carton;
FIG. 3 is a plan view of the transfer mechanism;
FIG. 4 is an elevational view of the transfer mechanism taken substantially along line 44 of FIG. 3 and showing some of the features of the feeding mechanism which comprises the subject matter of the present invention;
FIG. 5 is an elevational view taken substantially along the line 5-5 of FIG. 4, showing details of secondary driver mechanism; and
FIG. 6 is an elevational view, partly in section, of the primary driver assembly, taken along line 66 of FIG. 3.
While the invention is illustrated and described in some detail with reference to a particular embodiment and mode thereof, there is no intention that it be limited to such detail. On the contrary, it is the intention to cover all alternative constructions and equivalents falling within the spirit and scope of the invention as defined by the appended claims.
Referring more specifically to FIG. 1, the invention is there exemplified in an illustrative machine 50 adapted to receive a supply of flattened tubular carton blanks 30, such as shown in FIG. 2, process them automatically at high speed, and to discharge them in the form of filled and sealed cartons 31, FIG. 20. Before presenting a detailed description of the machine 50, however, it would :be desirable to outline briefly the salient features of the carton blank 30 and the carton 31 processed by the machine 50.
A flattened tubular blank 30 (FIG. 2) is formed from a flat blank of paperboard or the like, coated on both sides with thermoplastic material such as polyethylene, folding the flat blank together and gluing the side seam. Each flattened tubular blank 30 is squared out at the rotary transfer station by the rotary transfer mechanism until it is approximately tubular in shape, as shown in FIG. 2a. The completed carton 31, shown in FIG. 20, comprises a tubular body of generally rectangular cross section having a bottom closure and a top closure. Both the top and bottom closures are formed from integral extensions of the carton body and are held and sealed together in a manner which will be described hereinafter.-
The carton blank is divided by means of an appropriate pattern of score lines into a plurality of panels and areas which are utilized for the walls and the closure parts of the carton. Upon reference to FIGS. 2, 2a and 2b, which illustrate the blank, it will be noted that the body portion is defined by four side panels 32, 32a, 33 and 33a, and a side seam flap 34 which is adhesively secured to the inner face of the side panel 33a.
The bottom closure 35 is defined by a bottom panel which is an integral extension of the side panels. All the bottom closure panels are integral parts of the blank and adjacent ones are separated from each other only by score lines which ultimately define the various folds or creases required to complete formation of the bottom closure. When the bottom closure is formed, the panels fold inwardly toward one another and the respective pairs of smaller triangular panels associated with them are infolded against the inner faces of the major bottom panels. The bottom closure parts, when fully infolded, are pressed flat and heat sealed in this position.
The top closure 36 has substantially a gable top configuration comprising a pair of inclined roof panel 39 and 39a, surmounted by an upstanding top rib 40.
The top closure of the carton 31 includes an extensible pouring spout, which, initially is disposed in a tucked-in position within the top closure and protectively sealed by means of sealing panels which are abuttingly secured together along the entire length 'of the top rib. To facilitate opening of the carton 31, and for accessibility of the pouring spout, the pouring edges of the latter, together with the major are-as of the inner rib panels, may be covered with a patch or lip 37 of adhesive or non-adhesive material. By this is meant a material which will not bond to itself or to the thermoplastic coating on the surfaces of the blank during heat sealing of the top closure.
General machine organization Referring more particularly to FIG. 1, the illustrative machine 50 is especially suited to the high speed erection and filling of the cartons. A supply 'of flat side seamed blanks for such cartons is stacked in a magazine from 3 which the blanks are successively withdrawn, erected into open-ended tubular form and loaded top first straight down onto the mandrels of a multi-station bottom forming rotary mandrel assembly on which the bottom closures are formed and sealed as the rotary mandrel assembly is indexed through its stations. Following the formation of the bottom closures, the semi-formed cartons are successively ejected from the mandrels and conveyed bottom first along a tubular trackway defined by spaced parallel strips, being inverted in the course of such movement to arrive upright at a conveyor. The cartons are then transferred along a straight path through the machine to top breaker and steepler mechanisms, resulting in breaking or flexing of the top closure elements about their score lines, a filler mechanism, and then beneath the top heater, the closure and sealer units which activate .the thermoplastic and then seal the top closure elements of the carton respectively. Following this, the filled and sealed cartons are discharged in a continuous procession from the machine. For convenience, the partially completed cartons will be designated by the reference numeral 30 at their various stages of completion in the machine, and by the numeral 31 upon emergence from the machine as a finished product.
The machine 50 comprises a machine base supported on legs and supplied with utilities, such as electric power, compressed air, gas fuel and cooling water from appropriate external sources. A magazine 53 is mounted on top of the right end of the machine as viewed in FIG. 1. Operatively associated with the magazine and mounted adjacent to it on platform 61 is a rotary transfer mechanism 60, such as shown and described in U.S. Patent No. 2,936,681, issued May 7, 1960. The transfer mechanism 60 (FIG. 1) is adapted to withdraw carton blanks successively from the magazine, erect them into openended tubular form and then load them into the rotary mandrel assembly for bottom closing. For such purpose, these mechanisms are driven in synchronism with each other from the main drive of the machine.
A rotary mandrel assembly 70, with a plurality of mandrels 71, to which the carton blanks are transferred by the carton transfer mechanism 100 after being erected into tubular form, is situated below the transfer mechanism. The rotary mandrel assembly 70 is adapted to receive the carton blanks successively from the transfer mechanism 100, top down, and to move the cartons from station to station in an orbital path to form their bottom closure. The blanks are then ejected and presented upright to the filler mechanism 90 by means of transfer chute 54 from whence they are filled successively, and while still open at the top move under top heater and closure units to be successively sealed. After final sealing, the filled cartons are discharged from the machine.
Rotary mandrel assembly For bottom closure forming, the tubular blank 30 is loaded on a mandrel 71 of an intermittently driven mandrel assembly 70 carrying a plurality of such radially disposed mandrels, in this instance, ten in number, and a plurality of cooperating station units with which the mandrels are adapted to register sequentially during the course of their intermittent or indexing movement. The station units are a bottom breaker unit 72, a plurality of heater units 73, 74 and 75, a bottom closing unit 76, and two bottom sealing units 77 and 78.
Each mandrel 71 is a square in cross section and adapted to receive the tubular carton blank 30'. After the loading of an open-ended, top down, carton blank 30 on a mandrel 71, by the transfer mechanism 100, in a manner which will hereinafter be described, the mandrel assembly moves through an indexing step, thereby bringing the blank to register with the bottom breaker unit 72. Details of a suitable breaker unit 72 are fully disclosed in application Ser. No. 67,842, filed Nov. 7, 1960, entitled, Machine for Forming Plastic Coated Paperboard Containers. In this position, all the bottom closure panels 36 overhang the end of the mandrel and the common score lines connecting them to the carton side panels are approximately even with the end face of the mandrel. The bottom breaker unit 72 is adapted to effect substantial prebending of the bottom closure parts on their respective score lines and toward their closed position. The prebending action is carried to a sufficient extent to create along each score line, insofar as possible, a permanent set in the paperboard and its thermoplastic coating. This greatly facilitates the subsequent closing and sealing of the bottom closure elements of the carton blank.
Following the bottom breaking operation, the mandrel assembly indexes the carton 30 around the heater stations 73, 74 and 75. In order to avoid overheating of the bottom with possible damage to the paperboard or the thermoplastic coating, and yet drive sufficient heat into the bottom closure panels to achieve effective sealing, resort is had to a series of heating stations, in this instance, three in number (FIG. 1). These stations are substantially identical and are adapted to apply warm air to both sides of the bottom closure panels so as to raise their temperature sufiiciently to activate the adhesive action of the thermoplastic coating on the carton blank.
Air is supplied to the heater stations 73, 74 and 75 by means of a vertical manifold 79 which is connected to a blower 80. Combustion occurs in the burner assembly (not shown) and is controlled so as to provide a discharge of heated air to the heater stations 73, 74 and 75. By the time the blank 30 is ready to leave the last heater station 75, its bottom closure panels 36 have been heated to the proper temperature and are ready for closing and sealing.
After the heating operation, the mandrel assembly indexes and carries the blank 30 from the last heater unit 75 to the bottom closing unit on station 76. At this point, the bottom closure panels have been heated to a temperature suflicient to activate the adhesive action of their thermoplastic coating, and to efiFect adherence to itself to provide a sealed bottom end 38 of the carton blank (see FIG. 2b).
From the bottom closing unit 76, the blank 30 passes to the bottom sealing units 77 and 78. The latter are substantially identical and, therefore, two such units are used in order to subject the bottom closure to pressure for the necessary total interval of sealing time. After the bottom seal is completed (see FIG. 2b), the mandrel assembly indexes through another step and carries the blank 30 to a transfer station, where, as shown in FIG. 1, the mandrel and blank 30 are upwardly inclined and the bottom closure occupies a radially outward position on the mandrel. The blank 30 is hereupon ejected from the mandrel by air pressure jets emitted from ports in the end of the mandrel (not shown).
Filler and top closure units The carton 30 is conveyed directly from the mandrel assembly to the conveyor mechanism 54 through an elevated open trackway or slide defined by parallel spaced rods. The air blast ejecting the carton 30 from the mandrel causes the carton to move, bottom first, up a slight incline in the trackway over the peak from where it will slide down the opposite slope to the delivery station 55. The terminal portion of the trackway is substantially vertical so that the carton is delivered upright to the conveyor and in position to be filled by passing the top open cartons underneath the filler unit 90, from whence the cartons are filled. Such mechanism operates to fill a predetermined charge of milk or other product into the open topped cartons. After the cartons are filled, means are provided for heating the surfaces of the top panels 35 of the carton blank 30, and for pressing these heated surfaces together to effect a seal of the carton closure. As shown in FIG. 20, panels 35 are sealed in a gable top configuration comprising a pair of inclined roof panels 39 surmounted by an upstanding top rib 40.
After the cartons 31 have been filled and sealed, they are moved to a delivery section 91 from which the cartons may be packed or cased as desired.
Carton transfer mechanism In accordance with the present invention, the carton blar'ik is successively withdrawn from the magazine and advanced in a controlled path around the rotating transfer turret 60, simultaneously erecting the carton blank into an open-ended tubular form, from whence it is transferred onto the mandrel 71 of the rotary mandrel assembly. The blank 30, as indicated dotted line configuration in FIG. 3, is shown in its squared-out tubular form as it is being conveyed down the transfer chute of the present invention. Prior to the present invention, the carton blank was transferred by a pusher or paddle mechanism, in which the downward stroke of the paddle drove the open-ended squared carton blank downwardly onto the mandrel 71.
Referring more specifically to FIGS. 3, 4, 5 and 6, the carton transfer unit 100 is shown comprising a primary drive assembly 101 and a secondary driver assembly 126. The primary driver assembly 101 comprises a main body portion 102 and an adjustable body portion 103 mounted for vertical adjustment to provide proper tension of belts 104 rotating on upper idler pulleys 105 and lower driving pulleys 106. A spring 107 mounted in recess 108 of the main body portion 102 provides proper tension of belts 104 by means of maintaining pressure on plug 109 which is attached to the upper body portion 103. The upper body portion is adjusta'bly secured to the main body portion by bolts (not shown) when proper tensioning of the belts is achieved.
The primary driver is secured to a rear mounting plate 110 which is in turn mounted on the base or platform 61 of the machine. A motor 112 is mounted on the platform 61 to provide a rotative force to the belts by means of driving belt 113 rotated by motor pulley 114. Rotation of the driving belt 113 in turn rotates main drive pulley 115 which is keyed or connected to shaft 116. Shaft 116 is rotatably mounted in bearings (not shown), and held in spaced relationship by means of a guide arm 117 and the lower end of main body portion 102. The guide arm 117 is mounted on the body portion 102 by bolts 111 (see FIG. 6). Rotatably mounted, and in conjunction with the shaft 116, main drive pulley 115, and lower driving pulleys 106, is a transfer pulley 118, which transfers rotative motion to a shaft 119 by means of a pulley 157 driven by a secondary driving belt 120, (see FIGS. 3 and 4). Shaft 119 is rotatably mounted in bearings (not shown) in bracket 121. Bracket 121 is adjustably mounted in guided slots 122 of the guide arm 117 and secured thereto by bolts 123 to provide proper tensioning of the secondary driving belt 120, and proper meshing of the gear 124 with the gear 125 located on the secondary driver assembly 126 (see FIGS. 4 and 5).
The secondary driver assembly 126 comprises a main body portion 127 having a pair of belts 128 rotatable on pairs of upper idler pulleys 129 and lower driving pulleys 130. The lower driving pulleys 130 are splined or keyed to secondary driver assembly shaft 131 which is also keyed to gear 125. Thus, rotative motion of the belts on the primary and secondary driver assemblies are provided for by driving belts 113 and 120, respectively. Whereas the belts on the primary driver assembly are driven directly through rotation of shaft 116 (see FIG. 6), the belts on the secondary driver assembly are driven from rotation of shaft 131, which in turn is driven from rotation of shaft 119 and transferred thereto by means of gears 124 and 125 (see FIG. 5). It is noted that the drive shafts of each of the respective driver assemblies are connected to the lower pairs of pulleys, while the upper pairs of pulleys are rotatably driven by the respective belts; that is, the upper set of pulleys 129 on the secondary driver assembly is rotatable on shaft 132, and the upper set of pulleys of the primary driver assembly are rotatable on shaft 133.
While it is not shown, and the invention of which is not claimed, the shafts are rotatable in bearings that are set in the primary and secondary driver assemblies. HOW- ever, due to the rapid rotation of the shafts and pulleys, and the position of the respective invention in the machine complex, that is, near the heating apparatus for sealing the plastic container blanks (see FIG. 1), it was found necessary to provide proper cooling of the bearings. Fluid coolant passages are therefore provided for in the primary and secondary driver assemblies. As shown in FIG. 5, fluid coolant passage 134 is integral in the body portion of the secondary driver assembly and is provided with an entrance at 135 for connection to a flexible hose (not shown) and an exit 136 for the fluid coolant to leave the secondary driver assembly. In the primary driver assembly shown in FIG. 6, fluid coolant passages 137, 141 extend throughout the longitudinal length of the main body portion; however, at the upper end of the main body portion flexible tubing 138 and 140 provides a flexible connection to the fluid passage 139 of the adjustable body portion 103. The flexible connection affords movement of the adjustable body portion 103 with respect to the main body portion 102 in order to provide proper tension of belts 104. The fluid coolant passage 141 is connected to the guide arm 117 by means of lateral passage 142, transverse passage 143 and vertical passage 144 to exit 145. Entrance of the fluid coolant is provided at 146. It is readily apparent that the passage of fluid coolant enters the primary driver assembly at 146 through longitudinal fluid passage 137, through flexible tube 138 to fluid passage 139 of the adjustable body portion 103, through flexible tube 140, through vertical fluid passage 141 of the main body portion 104, to lateral passage 142, transverse passage 143, vertical passage 144 of the guide arm 117, and leaves through exit 145. Fluid coolant is constantly supplied through the passages to cool the bearings of the rotating shafts and pulleys.
To prevent excessive whiplash of the belts as they are being constantly rotated around the pulleys, and to provide minimum frictional resistance of these belts, lowfriction guides are mounted at each side of the driver assemblies. As shown in FIG. 6, low-friction guides 147 are mounted at each side of the main body portion 102 of the primary driver assembly with the belts 104 of the primary driver assembly fitting into the shallow grooves 148 of the low-friction guides 147. As shown in FIG. 5, low-friction guides 149 are mounted at each side of the main body portion 127 of the secondary driver assembly, with the belts 128 fitting into the shallow grooves 150 of the low-friction guides 149. However, it is to be understood that the present invention is not to be restricted to the use of round, or even oval-shaped, belts since flat belts are also adaptable. In the latter case, the shallow grooves formed in the low-friction guides may not be necessary. Consequently, the low-friction guides need not include grooves formed thereon to provide a pathway for the rotating belts.
The belts of each respective driver assembly are set apart from each other to provide a firm contact adjacent the corners of the container blank surfaces 32 and 32a (see FIG. 3). Each of the respective pairs of the belts of the primary and secondary driver assemblies is set apart oppositely, and the space contained therein is dimensionally less than the dimension of a carton blank in order that the carton blank will be gripped and conveyed along securely, and yet not too firmly to crush or permanently deform the sides. To provide for proper alignment and adjustment of the secondary driver assembly 126, a keyway 151 is integrally mounted outhe main body portion 127. Mounting holes 152 are set apart on each side of the keyway and are adapted to receive bolts (not shown) to secure the secondary driver assembly to the platform 61 of the machine 50.
To further prevent hanging up of the carton blank as it is being conveyed downwardly onto the mandrel 71 of the bottom forming mechanism 70, a guide plate 153, mounted on the platform 61 extends perpendicularly above and below the platform, includes guide rollers 154 which extend out a fraction of an inch. The guide rollers extend out just enough to prevent hanging up of the carton blank as it glides downwardly through the space or passage between the primary and secondary driver assemblies onto the mandrel of the bottom forming mechanism. As shown in FIG. 6, lower guide plate 155 is mounted below the surface of the platform 61 and includes only one guide roller. As can be best appreciated and understood from a view of FIG. 3, the rollers are mounted perpendicular to the longitudinal axis of the driver assemblies to provide a rolling contact to the surfaces of the carton blank as it is being conveyed downwardly onto the mandrel.
In accordance with the invention, the open-ended carton blank 30 is spun off the transfer turret 60 and, guided by rail 156, glides over the secondary driver assembly 126 to abut one panel (for example 32, as shown in FIG. 3) against the constantly rotating belts 104 of the primary driver assembly. As best seen and appreciated from a view of FIG. 4, as soon as the carton blank 30 is contacted by the belts 104 of the primary driver assembly, it is conveyed downwardly just enough distance for the carton blank surface 32a to be contacted by the constantly rotating belts 128 of the secondary driver assembly. The distance between the belts of primary and secondary driver assemblies is fractionally lesser than the dimension of the carton blank so that there is maintained a slight but firm pressure contact on the blank faces 32 and 32a as it is being conveyed downwardly. The guide rollers 154 on the guide plates 153 and 155 provide stability to the carton blank faces 33 and 33a and prevent hanging up of the carton blank 30 as it is being conveyed downwardly.
By the foregoing structure disclosed, there is provided a carton loading mechanism for removing carton blanks from the transfer turret, squaring them out, and discharging them onto the mandrel of a bottom forming mechanism. The apparatus is directed toward an improvement of the pusher or paddle mechanism shown in Patent No. 2,887,021, issued May 19, 1959, and Patent No. 2,957,- 289, issued Oct. 25, 1960.
While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.
What is claimed is:
1. In a container fabricating machine, a transfer mechanism for moving thermoplastic coated open-ended squared tubular container blanks of paperboard or the like from a transfer turret downwardly to an assembly of mandrels journalled on said machine and intermittently driven so as to be indexable about a fixed horizontal axis, each mandrel being square in cross-section and adapted to receive a squared container blank when indexed to a vertical position, said transfer means comprising; a primary driver assembly and a secondary driver assembly, said primary driver assembly comprising a first pair of upper rotatable pulleys mounted on a first horizontal idler shaft and a first pair of lower rotatable pulleys mounted on a horizontal main driving shaft, said idler shaft and said main driving shaft lying in a first common vertical plane, a first pair of vertically spaced parallel endless belts mounted on respective ones of said first upper and lower pair of pulleys adapted for high speed rotation, said secondary driver assembly comprising a second pair of upper rotatable pulleys mounted on a second horizontal idler shaft and a second pair of lower rotatable pulleys mounted on a second horizontal driving shaft, said second pair of lower pulleys positioned at substantially the same elevation as said first pair of lower pulleys, said second idler shaft and said second driving shaft lying in a second common vertical plane parallel to the first common vertical plane, a second pair of vertically spaced parallel endless belts mounted on respective ones of said second upper and lower pair of pulleys to provide high speed rotation thereof, said second idler shaft positioned below said first idler shaft a distance greater than one half the vertical distance between said first idler shaft and said main driving shaft wherein a tubular blank positioned with its principal axis vertical can be moved by the transfer turret horizontally over said secondary driver assembly to initially abut one panel of the blank against said first-pair of belts, said first and second pairs of belts set apart in opposed relation wherein the distance therebetween is dimensionally less than the dimension between opposed panels of the squared tubular container blanks wherein there is maintained a slight pressure contact on the opposed panels of each blank as it is being conveyed in a vertical path downwardly between said opposcd pairs of belts onto a vertically positioned mandrel.
2. The combination of claim 1 further comprising fluid coolant passages integral in said primary and secondary driver assemblies.
3. The combination of claim 1 further comprising guide plates adjacent the sides of said primary and secondary driver assemblies to provide alignment of the container blank as it is being directed along the path.
4. The combination of claim 3 further including guide rollers mounted longitudinally along said guide plates.
5. In a container fabricating machine, a high speed carton loading machine comprising: a primary driver assembly mounted on said machine and a secondary driver assembly mounted on said machine a preselected distance apart from said primary driver assembly; said primary driver assembly including a first main body portion and an adjustable upper portion, low-friction guides having grooves therein mounted on each side of said first main body portion, a first idler shaft mounted in said upper portion having a pair of idler pulleys mounted at each side of said upper portion, a main drive shaft mounted at the lower end of said main body portion having a pair of driving pulleys mounted at each side of said main body portion, said first pair of idler pulleys and driving pulleys being in-line with said grooves of said low-friction guides, a first pair of vertically spaced parallel endless belts, each of said first pair of belts mounted on respective ones of said in-lined first idler and driving pair of pulleys and tensioned by adjusting said upper portion with respect to said main body portion, a drive pulley on said main drive shaft being rotatable by a driving belt connected to a constantly rotating motor, said main drive shaft including a second drive pulley, said secondary driver assembly including a second main body portion, grooved low-frictioned guides mounted at each side of said second main body portion, a second idler shaft mounted at the upper end of said second main body portion, a second pair of idler pulleys mounted on said second idler shaft at each side of said second main body portion, a second drive shaft mounted at the lower end of said second main body portion, a second pair of driving pulleys mounted on said lower shaft at each side of said second main body portion, a second pair of vertically spaced parallel endless 'belts, each of said second pair of belts mounted on respective ones of said in-lined second idler and driving pair of pulleys, a first gear mounted on said second drive shaft, an adjustable bracket mounted on said machine supporting a bracket shaft, a pulley mounted for rotation on said bracket shaft, a second gear mounted on said bracket shaft for rotation therewith, said second gear adapted to rotate said first gear on said secondary driver assembly by means of rotation of said bracket 9 10 pulley, a secondary driving belt mounted on said bracket said first and second pairs of belts between said primary pulley and said pulley of said primary driver shaft, and Secondary dTlVer assemblleswhereby rotation of said primary driving belt rotates References Cited the main dIlVlIlg shaft together With said first pair of belts on said primary driver assembly, and rotation of 5 UNITED ST ATES PATENTS said secondary driving belt elfects proper directional 2,077,000 4/1937 Mlner 198ml rotation of said second pair of belts on said secondary g; clercq driver assembly in conjunction with said first pair of ay n belts, whereby a container blank may be conveyed along 10 GRANVILLE Y. CUSTER, Primary Examiner.