Patent Publication Number: US-3877353-A

Title: Stripping device

Description:
United States Patent [191 Smith et a1.  
 [451 Apr. 15, 1975 STRIPPING DEVICE [75] Inventors: Walter S. Smith, Naperville; Joseph E. Mazur, Chicago, both of I11.  
 [73] Assignee: Rockwell InternationalCorporation,  
 Pittsburgh, Pa.  
 [22] Filed: Nov. 12, 1973 [21] Appl. No.: 414,912  
 [52] US. Cl 93/36 A; 83/103; 83/116 [51] Int. Cl B3lb 1/74 [58] Field of Search 83/103, 115, 116; 225/97;  
 93/36 A, 58 P, 58.5, 59 ES [56] References Cited UNITED STATES PATENTS 475,246 5/1892 Morton 93/36 A 3,320,864 5/1967 Zernov 93/36 A 3,371,584 3/1968 Zernov 93/36 A 3,404,607 10/1968 Feick et al... 93/36 A 3,435,737 4/1969 Sarka 93/36 A 3,503,309 3/1970 Jones 93/36 A Primary Examiner-Roy Lake Assistant Examiner .la&#39;mes F. Coan [57] ABSTRACT A rotatable pin cylinder and a coacting backing or anvil roller define a nip through which die cut and creased sheet material is fed to have intervening waste pieces removed. A hollow cylinder or combing drum is telescoped over the pin cylinder for rotation about an axis which is eccentric with respect to the pin cylinder axis. The drum and cylinder and driven in unison and as they rotate through a complete cycle, radially projecting stripper pins carried by the pin cylinder are caused to project through apertures in the combing drum to impale and separate waste pieces from the sheet material in the area of the stripping nip. Thereafter the pins are progressively retracted within the periphery of the combing drum to positively eject the waste pieces in an area approximately opposite the stripping nip.  
 6 Claims, 3 Drawing Figures STRIPPING DEVICE SUMMARY The invention pertains to a stripping device for removing waste pieces from die cut and creased sheets or webs of carton material and which comprises spaced side frames for rotatably supporting an anvil roller and a coacting pin cylinder. The anvil roller and pin cylinder are positioned on opposite sides of the sheet path and define a stripping nip through which the die cut sheets are fed. Endless combining means, preferably in the form of a hollow cylinder or combing drum having a diameter greater than that of the pin cylinder, is telescoped over the pin cylinder for rotation about an axis eccentric with respect to the pin cylinder axis and in a manner that its surface is closely adjacent the periphery of the pin cylinder in the region of the stripping nip and is spaced at a maximum distance from the pin cylinder in the region diametrically opposite the stripping nip. A plurality of stripper pins carried by the pin cylinder are adapted to project radially through apertures in the combining drum to impale and separate waste pieces from the sheets as they travel in unison through the stripping nip whereupon the stripper pins are progressively retracted within the combing drum to positively eject the waste pieces as they travel through the region opposite the stripping nip. The stripper pins are designed so as to be quickly installed on or removed from the pin cylinder and the pin cylinder and combining drum. in turn. are supported for rapid removal and replacement in the stripping unit to facilitate off-press make-ready and thereby minimize down time between jobs.  
 DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side elevational view of a stripping device embodying the invention with parts being shown in section for clarity,  
 FIG. 2 is an enlarged view of a stripper pin, and;  
  FIG. 3 is a front elevational view, partly in section and illustrating the mounting arrangement for the respective members.  
 DETAILED DESCRIPTION With reference now to the drawings and particularly FIG. 1 thereof, a stripping device embodying the present invention is illustrated as comprising a backing or anvil roller having a resilient covering 11 thereon. The roller 10 is mounted for rotation about an axis located above the path of the sheets 12. A pin cylinder 13, having coaction with the anvil roller 10, is mounted for rotation about an axis located below the path of the sheets and said pin cylinder and anvil roller together define a stripping nip 14 through which the die cut and creased paper board sheets 12 or other flat material are adapted to be fed. The sheets may be die cut and/or creased and/or perforated at points along a predetermined line. Reference hereinafter to pre-creased sheets is meant to include any of the aforementioned means of cutting or scoring.  
  Feed means in the form of coacting endless conveyor belts 16 and 17 are adapted to receive the pre-creased sheets as they are delivered from a cutting and creasing press, not shown, and then advance them in regular order to the stripping nip 14. As they pass through the stripping nip 14, the anvil roller 10 provides a backing for the sheets so that a multiplicity of stripper pins 18 carried by the pin cylinder 13 can impale the waste pieces W thereon and separate them from the portions of said sheets constituting the carton blanks. Upon leaving the stripping nip, the carton blanks are directed between coacting endless delivery conveyor belts 19 and 20 for delivery to a suitable stacking mechanism, not shown.  
  The number of stripper pins 18 carried by the pin cylinder 13 is dictated by the number of waste pieces to be removed from the sheets and it will be understood that the pins are located in selected positions both circumferentially and axially of the pin cylinder so that at least one such pin is adapted to coincide with and impale each waste piece W as the pins and sheets move in unison through the stripping nip 14.  
  To facilitate the separation of the waste pieces W from. the sheets, the latter are supported as they pass through the nip 14, by a series of spaced riders or wires 22. These wires extend through the nip I4 and are fastened at each end thereof to brackets 23 which are, in turn, mounted on transverse rods 24 extending between the side frames of the stripping unit. The brackets 23 are adjustable axially of the rods 24 so that the wires 22 can be positioned atspaced intervals to&#39;support the carton blank portions of the sheets and thereby provide space for the waste pieces to pass therebetween.  
  The structure thus far described is relatively conventional. Stripping units having comparable coacting elements are old and well known. Such devices have proved effective for separating the waste pieces from the sheets of carton blanks but, after biengseparated from the sheets, the waste pieces tend to cling tenaciously on the stripper pins and the provision of reliable means capable of consistently and positively removing the waste pieces from the pins after they leave the stripping nip has heretofore presented a critical problem.  
  As will now be described, the present invention is directed to relatively simple, but highly effective means for ejecting the waste pieces from the stripper pins which is positive in its function and yet does not involve an excessive number of moving parts which would be subject to wear and possible jamming.  
  The apparatus essentially consists of an endless pin combing means, preferably in the form of a hollow cylinder or drum 30 which may be fabricated from rela tively thin walled metal tubing having a diameter greater than that of the pin cylinder 13. The combing drum is axially coextensive with the pin cylinder 13 and is mounted for independent rotation about an axis which is eccentric with respect to the axis of the pin cylinder. As will be evident from FIG. 1, the axis of the combing drum is coincident with a plane extending through the axes of the anvil roller 10 and pin cylinder 13 but is spaced farther from the anvil roller axis than is the pin cylinder. The degree of eccentricity of the pin cylinder and combing drum is such that, in the zone of area of the stripping nip 14, the wall or peripheral surface of the combing drum will travel in a path that is intermediate the surface of the pin cylinder 13 and the projecting tips of the stripper pins 18 whereas in the zone or area opposite the stripping nip the peripheral surface of the combing drum will be spaced radially behond the tips of the stripper pins.  
  It will thus be evident that as the pin cylinder and combing drum rotate about their respective axes at the same angular velocity, the tips of the stripper pins 18 will project through and beyond the peripheral surface of the combing drum 30 to thereby impale and separate the waste pieces W from the sheets as they travel in unison through the stripping nip. Upon leaving the stripping nip, however, the stripper fingers will be progressively withdrawn within the peripheral surface of the combing drum which surface will thus function to positively eject the waste pieces from the stripper pins in a continuous manner as they travel through a zone or area opposite the stripping nip.  
  To accommodate the stripper pins 18, the combing drum 30 is provided with apertures or slots 31 in its peripheral surface which are located so as to coincide with the stripper pins and which are of sufficient length circumferentially to accommodate the small angular changes of the stripper pins relative to the combing drum, due to the eccentricity of said drum and pin cylinder, and to provide adequate clearance for the installation and removal of the pins from the pin cylinder. The width of the slots, however, is maintained at a min- -imum such that the stripper pins 18 can pass freely therethrough with minimum clearance and whereby the peripheral surface of the combing drum will provide a maximum shearing effect upon the waste pieces and positively remove them from the pins.  
  The stripper pins 18 are designed so as to be securely interlocked in their operative positions on the pin cylinder 13, but in a manner whereby they can be quickly removed and replaced if they become worn or damaged. As illustrated in FIG. 2, the stripper pins are preferably fabricated from sheet metal of the required thickness and they comprise an annular body portion 36 having a radially projecting finger 37 formed integral therewith which is provided at its extremity with a sharpened tip 38 to impale the waste pieces, and barbs 39 for interlocking with and positively removing the waste pieces from the sheets.  
  On the side thereof opposite the finger 37, the body portion is slotted as at 41 and is provided with spaced, radially projecting legs 42 and 43 resembling a split arrowhead. Both of said legs have an upwardly diverging edge 44 which extends from the tip 45 thereof to a point 46 where said edge intersects the wall 47 of a groove 48 formed in each leg 42 and 43 and which is further defined by the base 49 and the opposite wall 51 that is provided by an enlarged part 52 of the body portion 36.  
  The stripper pins 18 are adapted to be mounted in interlocking seats provided therefor on the pin cylinder 13 and which comrpise a circular aperture or radially disposed hole 56 which extends completely through the wall of the pin cylinder. A slot 57 having an arcuate base 58 is formed in the surface of the pin cylinder, said slot being centered with respect to the axis of the hole 56 and being of a depth such that oppositely disposed shoulders 59 are formed at the base of the slot and which have a cross sectional width substantially equal to the width of the groove 48 in the legs of the stripper pins 18. Accordingly, when a stripper pin is mounted on the pin cylinder, as illustrated in FIG. 1, the shoulders 59 will interlock with the grooves 48 in the stripper pin legs and the side walls 47 and 51 coact with said shoulders to prevent any relative radial movement of the stripper pins. In this respect, it will be noted that the wall 51 of the groove 48 is curved on a radius corresponding to the radius of curvature of the base 58 of the slot 57 to provide maximum contact area between the respective surfaces. This serves to stabilize the pin against relative movement circumferentially of the drum and the side walls of the slot 57 preclude any pivoting or twisting of the pins in the aperture 56.  
  To mount a stripper pin 18 in position on the pin cyl inder it is merely necessary to insert the tips 45 of the legs 4243 through the appropriate slot 31 in the combing drum 30 and into the hole 56 of the pin cylinder. By exerting pressure on the pin in a radial direction the diverging walls 44 coact to press the legs 42-43 together until the points 46 slip through the hole 56 whereupon the tension in the legs causes them to spring apart thereby positively interlocking the grooves 48 onto the shoulders 59. To remove the pins, a special plier type tool is used to compress the body portion 36 of the pin until the legs 42-43 contact each other. In this position the points 46 will clear the sides of the hole 56 and the stripper pin can readily be removed.  
  As was previously mentioned, the pin cylinder 13 and combing drum 30 are removably mounted in the stripping unit so that they can be drilled, slotted, assembled and made ready off press to thereby minimize down time between jobs. The mounting arrangement for these members will now be described with reference to FIG. 3, wherein the stripping unit is shown as comprising spaced side frames 61 and 62 for supporting the anvil roller 10, the pin cylinder 13 and the combing drum 30 for cooperative action.  
  The journalling means for the anvil roller 10 have not been illustrated in detail in the drawing since they are not critical to the invention. It will be understood, however, that the respective ends of said roller are suitably journalled for rotation in the side frames by means of anti-friction bearings.  
  At the drive end therof, to the left as viewed in FIG. 3, the pin cylinder 13 is arranged to be supported for rotation in the side frame 61 by a shaft 64 which extends axially through a bore 66 that is provided therefor in an axially projecting sleeve 67. The sleeve is mounted in an opening 68 in the side frame 61 and is secured in fixed position therein by means such as bolts 69. Anti-friction bearings 71 mounted within the bore 66 journal the shaft 64 for rotation therein and at the end thereof which projects outwardly beyond the sleeve 67, said shaft is provided&#39;with a gear 72 by means of which the shaft 64 and therewith the pin cylinder 13 are driven.  
  At its opposite or inner end the shaft 64 is provided with a disc 73 which is fixed to said shaft for rotation therewith and which is adapted to support the adjacent end of the pin cylinder 13. A reduced diameter shoulder 74 is provided about the periphery of the disc 73 on the side thereof facing the pin cylinder, and this shoulder has a radius such that it will fit snuggly into and thus support the adjacent end of the pin cylinder when the latter is inserted in its operative position.  
  In order to transmit the drive torque from the shaft 64 to the pin cylinder 13 without slippage, the edge of said cylinder is provided with one or more axially disposed slots, not shown, which are adapted to fit over a corresponding number of pins, also not shown, which project radially from the shoulder 74 when the pin cylinder is installed. The interlocking pins and slots assure a positive drive connection between the shaft 64 and the pin cylinder 13 during operation of the stripper unit and still permit quick removal and replacement of the cylinders for job changes.  
  The corresponding end of the combing drum 30 is supported for rotation independently of, but in unison with the pin cylinder 13, by means of a housing 76. This housing is mounted on bearings 77 for rotation about the axis of the sleeve 67 and it is provided with a gear 78 at one end thereof by means of which the housing and therewith the combing drum are driven. The gear 78 also meshes with a gear 79 on the shaft of the anvil roller and thus drives said roller in unison with the combing drum.  
  As in the case of the pin cylinder, the housing 76 is provided with a reduced diameter shoulder 80 which is adapted to telescope into and thereby support the adjacent end of the combing drum and similar slots and pins, not shown, are provided in the drum and shoulder, respectively, to positively transmit the drive torque from the housing to the drum.  
  It will be noted that the bore 66 in the sleeve 67 has its axis located eccentric with respect to the axis of said sleeve. The location of the respective axes is such that the surface of the pin cylinder is closely adjacent the combing drum 30 in the zone of the stripping nip l4 and is spaced substantially farther away from said drum in the region opposite said nip.  
  At the opposite ends thereof, to the right in FIG. 3, the pin cylinder and combing drum are similarly supported by an assembly which, however, is axially retractable as a unit to thereby facilitate installation and removal of said members. This assembly essentially comprises a main supporting shaft or arbor 83 which extends through a housing 84 that is mounted on the side frame 62. A flange 86, formed integral with the housing, has a reduced diameter shoulder 87 which fits into an opening in the side frame 62 and it is secured in fixed position on the side frame by means such as bolts 89.  
  The arbor 83 is non-rotatably mounted in the housing 84 by means such as a key and coating keyway, not shown. but it is adapted to be slidable axially therein between supporting and retracted positions relative to the pin cylinder and combing drum. The means for effecting axial movement of the arbor have not been shown but they consist essentially of an elongated rack attached to the arbor and which meshes with a pinion located within the housing 84 and which is adapted to be actuated by a control shaft indicated at 91.  
  At the end thereof projecting inside the side frame 62, the arbor 83 is provided with an axially projecting sleeve 92 having an eccentric bore 93 formed therein. One end of said sleeve is telescoped over and fixedly secured to the projecting end of the arbor whereas at its opposite end the sleeve provides support for a stub shaft 94 which is journalled for rotation within the bore 93 by bearings 96. A disc 97, which is essentially the same as the disc 73, is fixed to the projecting end of the stub shaft 94 and it has a reduced diameter shoulder 98 formed thereon to fit into and thus support the end of the pin cylinder 13.  
  The adjacent end of the combing drum, in turn, is supported by a housing 101 which is mounted on bearings 102 for free rotation about the axis of the sleeve 92. The housing has a reduced diameter shoulder 103 adapted to fit into and thus support the end of the drum.  
  Although the housing 101 and stub shaft 94 are freely rotatable relative to the supporting sleeve 92, they are secured against relative movement axially thereon.  
 Consequently,, when the arbor 83 is moved axially in the housing 84 from the operative position illustrated in FIG. 3 to a retracted position, to the right as viewed in said Figure, the housing 101 and disc 97 will move therewith to release the ends of the pin cylinder and combing drum. Said cylinder and drum can then be slipped off the disc 73 and housing 76, respectively, for removal from the stripping unit and be replaced by a different cylinder and drum which have previously been prepared for the next job to be stripped.  
  To control and drive the pre-creased sheets as they pass through the stripping nip 14 a plurality of endless, resilient bands or tires 105 preferably are mounted at spaced intervals about the periphery of the combing drum 30. These tires function to press the sheets against the anvil roller 10 and prevent them from being skewed or otherwise displaced by the impaling action of the stripper pins as they pass through the stripping nip. The tires obviously are located so as to contact the carton blanks in the sheets and thus not interfere with the impaling and removal of the waste pieces therefrom.  
  Although the means for driving the pin cylinder and combing drum have not been illustrated, it will be understood that the respective gears 72 and 78 are driven by separate drive gears mounted on a common drive shaft to drive the cylinder and drum at precisely the same angular velocity. Moreover, although the anvil roller, pin cylinder and combing drum illustrated in FIG. 3 are relatively short. it will be appreciated that these members may be of any practical length depending upon the width of the material to be processed and that the stripper pins 18 and clearance slots 31 can be located in any position about the peripheries of the pin cylinder and combing drum respectively to engage and remove waste pieces at any positions in the sheets.  
  From the foregoing description it will be apparent that a novel apparatus has been provided for stripping waste pieces from pre-creased sheets of carton blanks which includes simple, economical and highly efficient means for positively ejecting the waste pieces from the stripper pins after they have been separated from the sheets. No auxiliary elements or relatively moving parts that are subject to wear and/or jamming are involved and thus the apparatus is capable of continuous operation for extended periods.  
 We claim:  
  1. Stripping apparatus for separating waste pieces from precreased material comprising, a rotatable cylinder, stripper means mounted on said cylinder and having tips projecting radially beyond the surface of said cylinder, roller means mounted adjacent said cylinder and defining therewith a stripping nip, said roller means being adapted to coact with said stripper means to impale the waste pieces on the tips thereof as the sheet material moves through said stripping nip, a hollow drum telescoped over said cylinder, said hollow drum being coextensive axially with said cylinder and having apertures in the surface thereof in selected positions coinciding with the location of the stripper means on said cylinder, and means mounting said drum for independent rotation in unison with said cylinder about a fixed axis eccentric with respect to the cylinder axis whereby said drum surface is located intermediate the cylinder surface and the tips of said stripper means in the area of the stripping nip and is spaced radially outwardly beyond the tips of said stripper means in an area spaced from said stripping nip.  
  2. Stripping apparatus as set forth in claim 1 wherein said stripper means includes a plurality of individual releasable stripper pins having respective barbed wastecngaging tips for impaling the waste pieces.  
  3. Stripping apparatus as set forth in claim 1 further including drive means for independently rotating said cylinder and drum in unison about their respective axes and at the same angular velocity.  
  4. Stripping apparatus as set forth in claim 1, wherein said hollow drum is releasably supported on a disc at each end thereof. and said mounting means support said discs for rotation about an axis eccentric with recylinder.