US3382774A - Mandrel stripping mechanism - Google Patents

Description

May 14, 1968 Filed July 1966 F. L. HOFF MANDREL STRIPPING MECHANISM 6 Sheets-Sheet 1 INVENTOR FRANCIS L. HOFF ATTORNEY May 14, 1968 F. L. HOFF 3,382,774

MANDREL STRIPPING MECHANISM Filed July &, 1966 6 Sheets-Sheet 2 INVENTOR FRANCIS L. HOFF ATTORNEY May 14, 1968 F. L. HOFF 3,382,774

MANDREL STRIPPING MECHANISM Filed July 5, 1966 6 Sheets-Sheet S INVENTOR FRANCIS L. HOFF ATTORNEY May 14, 1968 F 1.. HOFF 3,382,774

MANDREL STRIPPING MECHANISM Filed July 5. 1966 6 Sheets-Sheet 4 INVENTOR FRANCIS L. HOFF AT ORNEY May 14, 1968 F. L. HOFF 3,382,774

MANDREL STRIPPING MECHANISM Filed July 3, 1966 6 Sheets-Sheet 5 INVENTOR FRANCIS L HOFF WWW ATTORNEY May 14, 1968 F. HOF'F 3,382,774

MANDREL STRIPPING MECHANISM Filed July 8, 1966 6 Shee+.sSheet 6 INVENTOR FRANCIS L. HOFF ATTORNEY nited States The present invention pertains to carton forming and filling machines and more particularly relates to a mechanism for stripping cartons from a mandrel and for gripping the open ends thereof.

In carton forming and filling machines of the type disclosed in the copending US. Vadas et al. application Ser. No. 461,738, which application was filed on lune 7, 1965, and is assigned to the assignee of the present invention, a mechanism is provided for stripping the cartons from the mandrels. In the Vadas et al. mechanism a plurality of evenly spaced mandrels are mounted on a turret and extend radially outward therefrom. The mandrels have cartons thereon with their top closures open and with their bottom closures sealed and disposed at the outer ends of the mandrels. The mandrels with the cartons thereon are intermittently indexed into an unloading station where a reciprocable stripping mechanism moves stripping fingers radially from a retracted to an extended position into engagement with the top closure of the carton and then reverses its direction and pulls or strips the cartons off the mandrels when returning to the retracted position.

If the turret and stripping mechanism become improperly synchronized so that the turret begins swinging a mandrel out of the unloading station before the stripping fingers have moved the carton off the mandrel, mechanical interference will occur between the fingers and the mandrel which usually results in breakage of the fingers. The mandrel stripping mechanism of the present invention is arranged to prevent such breakage in the event the turret and stripping mechanism are improperly synchronized.

Another problem present in the prior art structure and solved by the mandrel stripping mechanism of the present invention is that inherent resilience in the carton tends to cause the open end of the carton to assume a diamondshaped configuration after it is stripped from the mandrel, rather than remaining in its desired square or rectangular configuration. If the open end of the carton is permitted to assume a diamon -shaped configuration, it has been determined that it becomes difficult to reliably grip and transfer the carton into other components of the carton forming and filling machine by means of a transfer mechanism such as that illustrated herein and disclosed and claimed in the copending US. Stevenson et al. application Ser. No. 563,875 which application was filed on even date herewith and is assigned to the assignee of the present invention.

It is therefore one object of the present invention to provide an improved mechanism for stripping a carton from a mandrel and for gripping the open end thereof.

Another object is to provide a mandrel stripping mechanism having a fail-safe device therein.

Another object is to provide a mandrel stripping mechanism having stripping fingers arranged to grip cartons so as to hold the top closures thereof in desired configuration.

These and other objects and advantages of the present invention will become apparent from the following description and accompanying drawings, in which:

FIGURE 1 is a plan illustrating the mandrel stripping mechanism of the present invention and the components associated therewith, the stripping mechanism being ice shown in the fully extended carton receiving position.

FIGURE 2 is a side elevation of the apparatus of FIG- URE 1 looking in the direction of arrows 22 of FIG- URE 1.

FIGURE 3 is an end elevation of the apparatus of FIGU E 1 looking in the direction of arrows 33 of FIGURE 1, the mandrel stripping mechanism being shown in a retracted carton delivering position.

FIGURE 4 is an enlarged vertical section taken along lines 44 of FIGURE 3 illustrating the relationship between the mandrel stripping mechanism and an unloading trough.

FIGURE 5 is an enlarged vertical section taken along lines 55 of FIGURE 1 illustrating carton guiding means associated with the mandrel stripping mechanism, only the carrier of the stripping mechanism being illustrated.

FIGURE 6 is a vertical section taken substantially along lines 66 of FIGURE 4 illustrating the manner in which the gripping fingers engage and grip a carton, said section being shown on the drawing containing FIG- URE 3.

FIGURE 7 is an elevation of one of the stripping fingers shown deflected out of its normal operating position by an improperly timed mandrel, certain parts being broken away.

FIGURE 8 is a dia rammatic plan illustrating the relationship of the several turrets associated with the mandrel stripping mechanism of the present invention, and illustrating the drive for the stripping mechanism and the turrets.

In genera the mandrel stripping mechanism 18 (FIGS. 1 3) of the present invention forms a part of a carton transfer apparatus 29 which receives two rows of cartons C with their bottom closures sealed from an upper series 22 and a lower series 24 of mandrels 25 which are supported by and are rigidly secured to an intermittently driven bottom forming turret .28. The reclprocable mandrel stripping mechanism 18 includes a pair of stripper fingers and 320: (FIG. 4) associated with each mandrel, which fingers simultaneously grip and strip cartons from one of the upper and from one of the lower mandrels 26,

p move the cartons onto an unloading trough 32. Be-

fore the stoped cartons are released by the stripping mechanism E3, the cartons are simultaneously gripped by an upper jaw and by a lower jaw 38 of one of a plurality of transfer heads 4%) of a continuously driven transfer mechanism which, in its preferred form is a turret 42. The upper 3 3 and lower jaw 38 removes the horizontally disposed cartons from gripping engagement with the fingers and from the unloading trough 32, pivots each carton from a horizontal to a vertical position, and then places the carton into spaced carriers 46 which are mounted on a single continuously driven conveyor 48 and include pivotal gates 50 which firmly clamp the lower end of each carton in its associated carrier. Substantially simultaneously as the cartons are being gripped by the associated carriers 4'5, the jaws 3'6 and 3-8 of the associated transfer head 4% are opened thereby releasing the two cartons "for movement along the single path of the conveyor l ne of a plurality of anvils 52, each of which is associated with a forming head 53 of a forming turret 54, is then lowered into the open upper end of the associated carton thus stabilizing .he upper end thereof while the j of the transfer head as return to the discharge station to grip another pair of cartons from the unloading trough 32.

More particularly, the cartons C, which are supported on the particular mandrels 25 of the upper series 22 and lower series 24 that are indexed at a mandrel unloading station 56, are strip ed from the two mandrels by the mandrel stripping mec anism 18 which is driven in timed 7 3 relation with the bottom forming turret 28. The bottom forming turret 28 is fully described in the previously mentioned Vadas et al. application and, accordingly, will not be described in detail herein except to state that the upper series 22 and lower series 24 of mandrels 26 are spaced at a predetermined distance apart, the preferred centerto-center distance being 6 inches.

The mandrel stripping mechanism 18 comprises a carrier 58 which is slidably received on a pair of parallel rods 66 and 62 which are rigidly secured to brackets 64 that are bolted to the frame 66 of the machine. The carrier 58 includes a horizontal base 68 having collars 70 and slide blocks '71 (FIG. thereon which are slidably supported on the rods 66 and 62, respectively. An upstanding finger supporting plate '72 is integral with the base 68 and includes three spaced horizontal finger supporting arms '73 which define horizontal slots 74 and 76 to permit the upper series 22 and lower series 24, respectively, of mandrels 26 to pass thercthrough in the event the forming turret 28 and mandrel stripping mechanism 18 should become improperly timed.

Each carton is engaged by an upper stripper finger 38 and of upper stripper finger assemblies 82 and 84 (FIGS. 4 and 6), by lower stripper finger 38a of lower stripper finger assemblies 86 and 88. The assemblies are substantially the same except that the upper stripper fingers 30 are shorter than the lower stripper finger film so as to engage carton end closure fiaps F1 and F2 respectively, which are of different lengths. Also, the upper fingers 38 are resiliently urged to pivot in a counterclockwise direction while the lover fingers are urged to pivot in a clockwise direction. Because the stripper finger assemblies 82, 84-, S6 and 88 are so similar, only the assembly 82 will be described in detail.

The stripper finger assembly 82 (FIGS. 4 and 6) comprises a shaft 90 journalled in a suitably bushed hub 92 formed on the free end of the upper finger supporting arm 73 and held from axial movement relative thereto by a large diameter portion 94 near one end, and a washer 96 and nut 98 screwed on the other end. A torsion spring 100 is wound around large diameter portion 94 of the shaft 90 and has one end connected thereto. The other end of the spring is connected to the hub 92 thereby urging the shaft 90 to pivot in a clockwise direction (FIG. 6).

The central portion 182 (FIG. 6) of the shaft 96 is of rectangular cross-section and is engaged by a stop bolt 1G4 screwed into the hub 92 and locked in desired position by a locknut 1'35 thereby limiting the amount of spring urged pivotal movement permitted of the shaft. The upper stripper finger 30 associated with stripper finger assembly 82 (FIG. 4) is internally slotted at 166 to receive one end of the shaft 98 and is connected to the shaft 96 by a pivot pin 108. The pivot pin connection causes rotation of the finger 30 with the shaft 9% about the longitudinal axis thereof, and also permits clockwise (FIG. 4) pivotal movement of the finger 38 about the axis of the pivot pin 108 as indicated in FIGURE 7 in the event the bottom forming turret 28 is improperly timed relative to the stripping mechanism 18 and causes a mandrel to contact the finger 30 when moving into the unloading station 56.

A notch 11!) is formed in the end of the shaft 96 and is engaged by the ball 112 of a ball detent 114 which is screwed into the finger 36. Thus, the finger 30 is normaliy held in the operative position by the ball deten 114, but may be shifted out of this position without damage to the finger 36, if one of the mandrels 26 of the bottom forming turret 28 should swing laterally against the associated finger 38 or 30a. Under such circumstances, it is apparent that the upper finger 30 will pivot in a counterclockwise direction (FIG. 4) about their pivot pins 168 while the lower fingers 36a will pivot in a clockwise direction.

As best shown in FIGURE 6, the free ends of each cooperating upper and lower pair of fingers 38 and 361! are provided with outwardly diverging notches 116 and 118, respectively, which notches receive and firmly grip the top closure flaps F1 and F2 during the mandrel stripping operation and retain their grip until after the cartons have been received and gripped by the jaws 36 and 38 of the transfer turret 42. It will be understood that the notches 116 and 118 grip the cartons with sufficient force to not only reliably hold the cartons in position to be received by the associated jaws, but also maintain the flaps which define the open ends of each carton in a square condition rather than permitting the open end to be forced into a diamond shape by inherent resilience in the walls of the carton.

The carrier 58 (FIG. 1) is reciprocated by a lever 124 which is secured to a shaft 126 that is pivoted in timed relation with the movement of the bottom forming turret 28 by means to be fully described hereinafter. In this regard, one end of a link 128 is pivotally connected to the carrier 58 and has its other end pivotally connected by a bolt or pin 130 to one of four openings 132, 134, 136 and 138 formed in the lever 124 depending upon whether quart, pint, one-third quart or one-half pint size cartons, respectively, are being handled. It will be understood that a carton stop 140 on each mandrel 26 will also be adjusted to accommodate the particular size of carton being handled as fully disclosed in the Vadas et al. application.

Pivotal movement of the shaft 126 in a clockwise direction (FIG. 2) causes the carrier 58 to move from the carton unloading position to the illustrated carton receiving position during which time the upper fingers 30 pivot in a counterclockwise direction (FIG. 6) and ride over the upper surface of the carton on the associated mandrel 26, and the lower fingers 30a pivot in a clockwise direction and ride across the lower surface of the carton 0n the associated mandrel 26. When the fingers 30 and 30a reach the carton receiving end of their stroke, they snap into carton receiving position under the influence of the torsion springs 100. The free ends of the fingers are, at this time, received in longitudinally extending slots 142 formed in the upper and lower surfaces of the mandrels 26, which slots extend the full length of the mandrels. Pivotal movement of the shaft 126 in the opposite, or counterclockwise direction (FIG. 1) then causes the fingers to move to the left (FIG. 1), thereby first seating carton flaps F1 and F2 in firm gripping engagement in the finger slots 116 and 118, respectively, as illustrated in FIGURE 6 and thereafter stripping the cartons off the upper and lower mandrels at the unloading station 56 for acceptance by the unloading trough 32 in position to be engaged and gripped by the jaws 36 and 38 of the transfer turret 42.

A drive mechanism (FIG. 8) is provided for drivmg the mandrel stripping mechanism 18 and the bottom forming turret 28 in timed relation. The drive mechanism 158 comprises a variable speed motor M which is connected by a belt drive 153 to an overload clutch 154 such as a Maxitorq clutch, Model No. 24, marketed by Carlyle Johnson Company, 52 Main St., Manchester, Conn. The clutch 154 drives a gear reducer 156 having an output shaft 158 connected by a flexible coupling 166 tothe input shaft 162 of a gear box 164 of an intermittent driving unit 166, which driving unit includes a vertically extending intermittently driven shaft 168 to which the bottom forming turret 28 is connected. A first continuously driven output shaft 170 of the gear box 164 is connected by a coupling 172 to a lower gear box 174 which is, in turn, coupled to an upper gear box 176 having a vertically extending output shaft 178. A crank disc 180 is keyed to the output shaft 178 and has a crank pin 182 adjacent its periphery which pin is pivotally attached to one end of a link 184. The other end of the link 184 is pivotally connected to a lever 186 which is secured to a vertical shaft 188 pivoted in the frame 66. Another lever 199 is secured to the shaft 188 and has its free end pivotally connected to one end of a link 192. The other end of the link 192 is connected to a lever 194 which is secured to the shaft 126. Thus, the previously mentioned lever 124 is oscillated causing the stripper finger carrier 58 (FIG. 1) of the mandrel stripping mechanism 18 to reciprocate thereby stripping cartons from the mandrels 26 in timed relation with the intermittent movement of the bottom forming turret 28 and placing the cartons in the pick-up station for acceptance by the transfer turret 42.

From the foregoing description it will be apparent that the mandrel stripping mechanism of the present invention includes a fail-safe device which prevents damage to the mechanism in the event the mandrel stripping mechanism and forming turret become improperly synchronized. The mandrel stripping mechanism also includes means for gripping the open top closure flaps of a carton to maintain the top closure flaps in a squared condition and to retain gripping control of the carton until the carton is gripped by a transfer mechanism and pulled free from the stripping mechanism.

While one embodiment of the invention has been shown and described, it will be understood that changes and modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

The present invention and the manner in which the same is to be used having thus been described, what is claimed as new and desired to be protected by Letters Patent is:

1. In a carton forming machine a mandrel stripping mechanism for stripping cartons of generally rectangular cross section with one end closed and the other end open from a mandrel comprising, the combination of an intermittently driven turret, a mandrel on said turret movable along a first predetermined path and intermittently indexed into an unloading station, stripping means movable between a retracted position out of the path of movement of said mandrel and an extended position in the path of movement of said mandrel, drive means for synchronizing the movement of said turret and said stripping means for effecting movement of said stripping means along a second path from the retracted position to the extended position and back to the retracted position While said mandrel is indexed at said unloading station, and failsafe means included in said stripping means for allowing movement of said stripping means laterally of said second path out of the path of movement of said mandrels in the event said mandrel moves out of the unloading station before said stripping means reaches said retracted position and contacts said stripping means.

2. An apparatus according to claim 1 wherein gripping 4. An apparatus according to claim 3 wherein inherent resilience of the carton tends to twist the open end of the carton when removed from the mandrel from a desired rectangular condition to a diamond-shaped condition, and wherein means defining slots are provided in each finger for receiving edges of opposed walls of the open end of the carton to grip the carton to maintain the open end in rectangular configuration.

5. An apparatus according to claim 1 wherein said stripping means includes a carrier movable along said second path, a pair of shafts journalled in said carrier with the shafts disposed on opposite sides of said first path and projecting outwardly from said carrier in a direction normal to said second path, a stripping finger pivotally connected to the end of each shaft and each finger having an end portion projecting into said first path, and said fail-safe means including resilient releasable means for normally holding said fingers from pivotal movement rela tive to said associated shafts.

6. An apparatus according to claim 5 wherein torsion springs are disposed between said carrier and said shafts for urging said fingers in opposite directions into the path of movement of said mandrel, and wherein adjustable stop means are provided between said shafts and said carrier for limiting the extent of pivotal movement of said fingers toward said mandrel, said fingers being deflected over the adjacent walls of the cartons against the urging of said torsion spring as said stripping means moves from the retracted to the extended position.

7. An apparatus according to claim 5 wherein means defining slots are provided in each finger for receiving opposed walls of the open end of the carton to grip the carton to maintain the open end in rectangular configuration.

8. An apparatus according to claim 6 wherein means defining slots are provided in each finger for receiving opposed walls of the open end of the carton to grip the carton to maintain the open end in rectangular configuration.

9. An apparatus according to claim 6 wherein the end of each shaft adjacent said stripping fingers are semicylindrical, and wherein each of said resilient releasable means is a ball detent which cooperates with a groove in the semi-cylindrical end of the associated shaft.

10. An apparatus according to claim 7 wherein the end of each of said shafts adjacent said stripping fingers are semi-cylindrical, and wherein each of said resilient releasable means is a ball detent which cooperates with a groove in the semi-cylindrical end of the associated shaft.

References Cited UNITED STATES PATENTS BERNARD STICKNEY, Primary Examiner.

Claims (1)

1. IN A CARTON FORMING MACHINE A MANDREL STRIPPING MECHANISM FOR STRIPPING CARTONS OF GENERALLY RECTANGULAR CROSS SECTION WITH ONE END CLOSED AND THE OTHER END OPEN FROM A MANDREL COMPRISING, THE COMBINATION OF AN INTERMITTENTLY DRIVEN TURRET, A MANDREL ON SAID TURRET MOVABLE ALONG A FIRST PREDETERMINED PATH AND INTERMITTENTLY INDEXED INTO AN UNLOADING STATION, STRIPPING MEANS MOVABLE BETWEEN A RETRACTED POSITION OUT OF THE PATH OF MOVEMENT OF SAID MANDREL AND AN EXTENDED POSITION IN THE PATH OF MOVEMENT OF SAID MANDREL, DRIVE MEANS FOR SYNCHRONIZING THE MOVEMENT OF SAID TURRET AND SAID STRIPPINGS MEANS FOR EFFECTING MOVEMENT OF SAID STRIPPING MEANS ALONG A SECOND PATH FROM THE RETRACTED POSITION TO THE EXTENDED POSITION AND BACK TO THE RETRACTED POSITION WHILE SAID MANDREL IS INDEXED AT SAID UNLOADING STATION, AND FAILSAFE MEANS INCLUDED IN SAID STRIPPING MEANS FOR ALLOWING MOVEMENT OF SAID STRIPPING MEANS LATERALLY OF SAID SECOND PATH OUT OF THE PATH OF MOVEMENT OF SAID MANDRELS IN THE EVENT SAID MANDREL MOVES OUT OF THE UNLOADING STATION BEFORE SAID STRIPPING MEANS REACHES SAID RETRACTED POSITION AND CONTACTS SAID STRIPPING MEANS.

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