US3370496A

US3370496A - Apparatus for intermittently advancing a web and cutting openings therein only during the movement of the web

Info

Publication number: US3370496A
Application number: US509751A
Authority: US
Inventors: Erhardt Stefan
Original assignee: BARTELT ENGINEERING CO Inc
Current assignee: BARTELT ENGINEERING CO Inc; BARTELT ENGINEERING COMPANY Inc
Priority date: 1965-11-26
Filing date: 1965-11-26
Publication date: 1968-02-27
Anticipated expiration: 1985-02-27

Description

3,3 70,496 CUTTING Feb. 27, 1968 s. ERHARDT ITTENTLY ADVANCING A WEB AND APPARATUS FOR INTERM OPENINGS THEREIN ONLY DURING THE MOVEMENT OF THE WEB Filed Nov. 26, 1965 2 Sheets-$heet 1 3 F210 6 zorEBm awe.

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APPARATUS FOR INTERMITTENTLY ADVANCING A WEB AND CUTTING OPENINGS THEREIN ONLY DURING THE MOVEMENT OF THE WEB Filed Nov. 26, 1965 2 Sheets-Sheet 2 Navar o-Tow astafouq lrhq r'df' 1; fi]%ll-MYJ"( aw qflwomosy/ United States Patent Ofiice 3,376,496 Patented Feb. 27, 1968 APPARATUS FOR INTERMITTENTLY ADVANC- ING A WEB AND CUTTING OPENINGS THERE- IN ONLY DURING THE MDVEMENT OF THE WEB Stefan Erhardt, Rockford, IlL, assignor to Bartelt Engineering Company, Inc., Rockford, 11]., a corporation of Delaware Filed Nov. 26, 1965, Ser. No. 509,751 6 Claims. (Cl. 83-297) ABSTRACT OF THE DISCLOSURE Parts of an automatic packaging machine for forming pouches from an elongated web advanced by drive rolls from a supply roll through a window-cutting station through a folding station and then through conventional sealing and severing stations. Between the cutting and folding stations, at web of transparent window material is fed into the web to cover one side thereof after folding. The drive rolls are turned intermittently in one direction by a conventional crank mechanism, and the windows are formed by a cutting mechanism including two rolls on opposite sides of the web, one roll being a backing and the other having a plurality of cutting elements with shaped edges equally spaced around its periphery. Through a drive cam and follower Wheel, the cutting mechanism is accelerated with the web during each step to a maximum speed and then decelerated with the web so that the cutting elements travel at the same varying speed as the web. A positive take-up mechanism adjusts the length of web between the drive rolls and the cutter mechanism, and an adjustment device changes the angular relation between the follower wheel and the cutter roll.

This invention relates to a machine for operating on an elongated web while advancing the latter intermittently along a predetermined path through the machine and, more particularly, to the cutting of a succession of longitudinally spaced openings in the web serving as windows in a series of edge-to-edge packages to be formed from the web. In intermittent motion machines, the various operations on the web customarily are performed by mechanisms which engage the web while the latter is stationary during the dwells between successive forward steps of the web. An example of the usual window-cutting mechanism is shown in Bartelt Patent No. 2,734,- 431.

The general object of the present invention is to obtain an improved and more effective window-cutting action in an intermittent motion machine, as compared to cutters of the type in the aforesaid patent.

A more specific object is to utilize a rotary cutter in an intermittent motion machine and to operate the cutter only while the web is advancing and at a varying speed matching the speed of the web thereby to form clean and accurately located windows while obtaining a more elfective cutting action, increased tool life, and smoother machine operation.

A further object is to correlate the speed of rotation of the cutter precisely with the varying speed of the web during each step in the advance of the latter thereby to move the cutting devices at a speed exactly matching the speed of the web.

Another object is to adjust the cutting mechanism quickly and easily to locate the position of each cut precisely relative to the portion of the web to be formed into a package.

Still another object is to minimize the amount of variation necessary in the cutter speed by performing the cutting operation during the portion of each step of the web in which there is the least variation in web speed.

Another object is to adjust the cycle of the cutter relative to the cycle of the web drive for easy correlation of the cutter speed relative to the web speed.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which FIGURE 1 is a perspective view of some of the main components of a packaging machine embodying the subject invention,

FIG. 2 is a graphic representation of the velocity of the shaft driving the web during one cycle of movement of the web through the machine of FIG. 1,

FIG. 3 is an enlarged perspective view of a pair of joined packages of the type that can be formed in the machine of FIG. 1,

FIG. 4 is a cross-sectional view along the line 44 of FIG. 3,

FIG. 5 is a cross-sectional view of a package positioned in the top sealing station of the packaging machine.

FIG. 6 is a fragmentary side elevation, partially in cross-section, showing the window cutting station of the machine, and

FIG. 7 is a fragmentary side-elevational view of phase adjusting apparatus for the roll cutter for adjusting the position of the web relative to the strip.

As shown in the drawings for purposes of illustration, the invention is embodied in an automatic packaging machine for forming envelope-type packages or pouches 10 (FIG. 3) from an elongated web 11 of packaging material and a strip 12 of transparent window-forming material that is disposed between the two

outside sheets

14 and 15 of the completed pouch to cover a window opening 16 formed in one of the sheets. Herein, the inner strip 12 is composed of a heat-scalable material such as polyethylene film which is fused under heat and pressure to the inner surfaces of the outer sheets to join the latter together at 17, 18 and 19 along both sides and the lower end of the pouch.

The upper edge of the strip 14 preferably is tack-sealed at 20 (FIG. 5) to the upper portion of the window sheet 12 and thus lies flat against this sheet when the upper end of the pouch is opened to receive the quantity of product to be packaged. Accordingly, the transparent strip covers the window opening 16 and cooperates with the sheet 15 in defining a pocket to receive the product. After the pouch is filled, a top seal (not shown) is applied along the upper edge 21 of the pouch to seal the two

outside sheets

14 and 15 together and close the pouch.

The relationship of the primary elements for forming such pouches is illustrated in FIG. 1 wherein it will be seen that the web 11 is drawn oif a supply roll 22 supported for rotation about a generally horizontal axis at one end of the machine, and is pulled endwise around a series of parallel guide rolls 23 and through a cutting station 24 where a series of longitudinally spaced window openings 16 is formed in one side edge portion of the web, herein the right portion as viewed in FIG. 1. The transparent strip 12 is drawn off a second supply roll 25 supported above the web and is guided around parallel rolls 26 and laid over the window openings as the web is drawn through a folding station 27 where the opposite side portions of the web are folded together into sideby-side vertical planes on opposite sides of the transparent strip. Beyond the folding station, the folded web passes through successive sealingstations 28 and 29 Where the tack seal 20, the

side seals

17 and 18, and the bottom seal 19 are applied, and through a cut-off station 30 the cut-off station and supported on the machine for rotation in engagement with the web in the directions indicated by the arrows in FIG. 1 so as to pull the Web step-by-step from right to left through the machine. As shown in FIG. 1, the draw rolls herein are supported for rotation about vertical .axes'on two parallel shafts 34 and 35 suitably journaled on the machine and connected to a drive mechanism 36 for rotating the draw rolls in unison in the appropriate directions.

The packaging machine is driven by a motor 37 which, through a gearbox 38, continuously rotates a cycle shaft 39 at a substantially constant speed in a counterclockwise direction in the drawing. This cycle shaft is coupled to an input shaft 40 of the drive mechanism 36 through a pair of sprocket wheels 41 and 42 and a driving chain 44. This input shaft is rotated continuously in a counterclockwise direction, as indicated by the arrow 45, and carries a radial driving crank 46 connected by a link 47 to a driven crank 48 on a parallel output shaft 49 connected by bevel gearing 50. to the draw roll shaft 34. The driving crank is fast on the shaft 40 and rotates continuously with the latter while the driven crank is mounted on a sleeve 52 telescoped loosely onto the output shaft 49 and adapted to be coupled to the latter by a one-way clutch 54 for transmitting the motion of the sleeve to the shaft V in only one direction of rotation, clockwise in this instance as indicated by the arrow 55. Thus, as the driving crank rotates continuously with the input shaft, the driven crank oscillates up and down through an are determined by the throw of the driving crank and advances the output shaft clockwise through the same arc during each successive down stroke of the driving crank. Through the bevel gearing 50, the output shaft turns the draw roll 31 counterclockwise while the other draw roll 32 is turned clock-wise by meshing gears 56 and 57 on the two draw roll shafts.

The driving crank 46 includes an arm 58 of channelshaped cross-section projecting radially from a hub 59 on the input shaft 40, and is connected to the lower end of the link 47 by means of a block 60 fitted in the groove 61 of the crank arm and pivoted on the link, the block being releasably clamped in -a selected position longitudinally of the crank. With this arrangement, the throw of the driving crank and the resulting arc of oscillation of the driven crank 48 are selectively adjustable to vary the length of web that is advanced during each cycle of the driving shaft and the resulting forward step of the web drive mechanism.

When the web is decorated with a repeating pattern or body of printed material to be located in the same position on each completed pouch 10, the

side seals

17 and 18 must be applied in substantially the same location relative to each pattern of decorated material. To insure the proper location of this material on each pouch, an automatic control is provided to sense the location of the pattern during each step andstop the advance of the web with the pattern in the same relation to the tooling each time. For this purpose, a photoelectric cell 62 (FIG. 1) is positioned along the path of the web at the level of a series of printed registration marks 64 spaced apart along the web between each successive pair of patterns. As a registration mark moves in front of the cell, the cell produces an electric signal that is used to apply a brake 65 mounted on the machine frame and, operable when 4 Y applied to stop the output shaft 49 whether or not th driving crank 46 has completed its downward swing.

Continued downward motion of the crank after application of the brake is accommodated by a yieldable connection between the opposite end portions of the link 47. Herein, the lower end portion of the link is a sleeve 66 pivoted on the block 69 and the upper end portion there- I of is formed by a rod 67 pivoted on the free end of the driven crank 48 and telescoped into the sleeve through an opening in the upper end wall thereof. A coiled compression spring 68 Within the sleeve urges the rod downwardly relative to the sleeve but'yields to permit the link to extend when the brake stops the output shaft and the driven crank during the downstroke.

It should be understood that the mechanism for supporting and advancing the web and forming the latter into pouches are known to those skilled in the art and thus need be described only generally herein. The. operations customarily are performed by reciprocating tools which engage the web during the dwell periods; For example, the tack seals 20 are applied by a seal bar 69 (FIG. 5 supported on one side of the-web at station 28 for movement into engagement with the sheet14 to press the latter and the transparent strip 12 against a splitter plate 70 between the strip and the other sheet 15 while a backing bar 71 engages the right-hand sheet 15. In the aforesaid patent, the'window openings 16 are formed in a similar manner by a reciprocating cutter mechanism. In accordance with the present invention, the window openings 16 are formed in the web 11 while the latter is advancing and with an improved cutting action resulting in substantially increased tool life and smoother machine operation as compared to prior intermittent motion machines. To these ends, the openings are produced at of the web to move in contact with the web at a varying speed precisely matching the-varying speed of the web.

Moreover, the position of the cut on each pouch and the cycle of the cutter drive relative tothe cycle of the web drive are adjustable to obtain optimum performance of the cutter. i

In this instance, the cutter 74 comprises a cylindrical roll 75 (FIGS. 1 and 6) supported on the machine frame ahead of the folding station 27 for rotation about :a horizontal axis below the plane of the web 11. Herein, the roll is mounted on a shaft 76 journaled in suitable bearings (not shown) at the ends of the roll. A plurality of cutting elements or dies 77 (FIG. 6) are spaced equally around the periphery of the roll beneath the right-hand portion of the web to engage the underside of the web as it passes over the cutter roll, and a back-up or pressure roll 78 positioned over the cutter roll engages the top of the web and forms an anvil for the cutting dies.

Each die 77 is an arcuate metal block (see FIG. 6) having a concave inner side 79 fitted against the periphery of the roll 75 and an outer cutting edge generally in the shape of the web openings to be formed. In this instance, each cutting edge has two concavely curved side sections 81 coaxial with the roll and disposed in spaced parallel planes perpendicular to the axis of the roll to form the straight upper and lower'sides 82 (FIG. 3) of the window opening 16, and has two curved end sections 84 for forming the curved ends 85 of the window opening. In the bottom of the hollow defined inside the cutting edge of each die is a hole 86 through which a cap screw 87 is threaded into the roll to hold the element securely on the periphery of the roll. Herein there are six such dies sixty degrees apart 5. Web While they are in engagement therewith. Herein, the arc of cutter rotation during each step is 120 degrees so that two dies 77 swing into engagement with the moving web and form the Windows in two successive package lengths during each step.

As shown in FIG. 1, the cutter drive mechanism 88 comprises an input shaft 89 coupled to the cycle shaft 39 by two sprocket wheels 90 and 91 on the respective shafts and an endless chain 92 trained around the sprockets to transmit the continuous rotation of the drive shaft to the input shaft. Mounted on and rotating with the input shaft is a cam drum 94 formed wih a peripheral groove 95 extending generally helically around the drum and traveling axially of the drum from left to right. An extension 96 of the cutter roll shaft 76 projects over the cam drum and carries a follower member 97 in the form of a cog wheel having a hub mounted on the extension shaft and a plurality of radially projecting follower lugs 98 equally spaced around the hub. The groove 95 receives the follower lugs when the latter project downwardly from the follower wheel and thus earns the lugs from left to right along the drum to rotate the wheel counterclockwise as the drum rotates counterclockwise as indicated in FIG. 1. The rate of rotation of the follower wheel is determined by the angle and resulting rate of axial travel of the portion of the groove acting on one of the lugs. The spacing of adjacent lugs and the length of the drum 94 are correlated so that each lug enters the left end of the groove before the preceding lug leaves the right end of the groove thereby providing continuity of cutter roll control. Thus, the drum and its related parts constitute means for activating the cutter during the advance of the web.

With this arrangement, the speed of rotation of the cutter 75 during each revolution of the cycle shaft 39 can be correlated precisely with the movement of the web during the same revolution of the drive shaft by varying the path and angle of the groove in accordance with the variations in web speed produced by the web drive mechanism. During each drive shaft revolution, the driving crank 46 pulls the driven crank 48 through one downstroke of selected arcuate length as the driving crank travels downward, and then returns the driven crank idly to its raised position during the upward motion of the driving crank. It will be evident that the velocity of the shaft 49, and of the web, will follow a harmonic curve as shown in FIG. 2, first accelerating from zero velocity at 103 (when the crank is at the top of its revolution) to a maximum velocity at 101 and beginning deceleration to return to zero velocity at 104 when the brake 65 is en gaged to remain idle until reaching point 105 when the cycle ends. Thus, the free end of the driven crank first swings down at the varying speeds illustrated between 100 and 104, which corresponds generally to 180 degrees of rotation of the cycle shaft 40 in the example shown, to turn the output shaft at a correspondingly varying rate of rotation, and then swings idly back to the top of its stroke during the period indicated between 104 and 105.

Accordingly, in the embodiment shown, the speed of the web during each step in its advance varies according to the portion of the velocity curve in FIG. 2 between the points 100 and 164 starting from zero velocity at 100 and accelerating to maximum velocity at 101 and then decelerating back to zero between points 102 and 104. For approximately the following half revolution of the cycle shaft and driven crank rotation, the web is stationary. The cam groove is laid out or programmed to produce rotation of the cutter shaft 76 corresponding to the rotation of the draw rolls 31 and 32 and thus to move the cutting elements 77 at a varying peripheral speed matching the web speed. For this purpose, the portion of the cam groove that acts on the log 98 during the dwell of the web has no slope longitudinally of the drum 94. Instead, this portion of the groove extends circumferentially of the drum so that the follower lug in the groove remains stationary.

As the crank 48 begins its downstroke and begins to turh the output shaft 49, the groove begins to spiral axially of the drum to start turning the follower wheel. The slope of the groove increases as the vertical velocity of the driving crank increases and thereby accelerates the cutter shaft 76 as the draw rolls are accelerated. As the web speed begins to drop at 101, the slope of the entering groove is reduced to decelerate the cutter in accordance with the deceleration of the web. At the point 191 the next active lug 98 is entering the cam groove and begins decelerating until it is in the circumferential portion of the groove, and thus receives no rotary motion from the drum. Again, this change in slope corresponds to the change in the vertical velocity of the driving crank to match the speed of the cutter to the speed of the web as the driving crank reaches the lower end of its down ward stroke.

Since printed matter frequently is included on the web 11, it is desirable to adjust the position on the web at which the window 16 is cut. To allow such adjustment, the drive shaft 76 for the cutter and the extension 96 connecting the drive shaft to the follower member 97 are joined by an adjustable coupling member 107. This coupling member comprises parallel plates 103 and 109 fixed to the adjacent ends of the shaft 76 and extension 96, respectively, and joined together by bolts 110 extending through arcuate slots 111 in the plate 109 and screwed into the other plate. By loosening these bolts, the plates can be freed to turn relative to each other to permit turning of the cutter while the web and cutter drive mechanism 88 remain stationary. In this manner, the position of the window on the web can be advanced or retracted by turning the cutter in the direction it normally is driven or in the opposite direction, respectively, so the cutting elements either reach the web sooner or later during each revolution of the input shaft 89. The chain 92 and sprocket wheels 90 and 91 provide a further adjustment of the cutter in this regard since the chain can be removed and the sprocket wheels turned relative to each other for angularly adjusting the cutter drive relative to the cycle shaft 39.

Another adjustment for varying the position on the web at which the window 15 is cut is provided in a take-up mechanism 112 (FIG. 1) positioned between the cutting station 24- and the folding station 27 where the web and sheet are joined. This take-up mechanism includes a pair of parallel rolls 114 journaled on the frame beneath the web and a third parallel roll 115 between and below the rolls 114 but disposed above the web to draw a downward loop in the web. The roll 115 is movable in a plane generally perpendicular to the web to vary the length of the loop and thus vary the position of the web relative to the window cutting station 24. The roll 115 is mounted to rotate on a shaft 116 (FIGS. 1 and 7) fixed to the end of a crank 117 having the other end fast on a shaft 118. By turning a wheel 119, the shaft 118 can be rotated through a cooperating worm 120 and gear 121 to turn the crank 117 and move the roll 115 through an arcuate path generally perpendicular to the web 11 for changing the length of the web between the supply roll 22 and the folding station 27, thereby to change the position of the Web relative to the cutter roll 75.

I claim as my invention:

1. In a machine for cutting window openings of preselected shape in an elongated web while advancing the latter intermittently through the machine, the combination of, means supporting the web for endwise motion along a predetermined path through a cutting station, a first drive mechanism advancing the web with an intermittent motion through successive forward steps and intervening dwells whereby the web is accelerated from a stop to a maximum speed and then decelerated to a stop during each forward step, a rotary cutter roll positioned on one side of said path at said cutting station and having cutting elements spaced around its periphery for rolling preselected arc in a direction to move successive cutting elements into contact with the 'web, then in the direction of advance of the web, and finally out of contact with the web, and cutter activating means for operating said second drive mechanism and rotating said cutter through said are during each forward step of the web to move said cutting elements at a variable speed matching the speed of the web while in contact therewith, accelerating said elements with the web to said maximum speed and then decelerating the elements with the web.

2. A machine as defined in claim 1 wherein said second drive mechanism and said activating means include a follower element connected to said cutter roll to rotate the latter in accordance with movement of said element, and a cam engaging and variably moving said element to produce the accelerating and decelerating movement of the element and said roll.

3. In a machine for cutting openings in an elongated web while advancing the latter intermittently through the machine, the combination of, means supporting the web for endwise motion along a predetermined path through a cutting station, a first drive mechanism advancing the web with an intermittent motion through successive forward and intervening dwells whereby the web is accelerated from a stop to a maximum speed and then decelerated to a stop during each forward step, a rotary cutter positioned on one side of said path at said cutting station and having a cutting element engageable with said Web to cut longitudinally spaced openings therein as the web passes 8 a through said cutting station, a second drive mechanism for rotating said cutter through a preselected arc in a direction to move said cutting element into contact with the web, then in the direction of advance of the web, and finally out of contact with the web, and means operating said second drive mechanism to rotate said cutter through said are during each forward step of the web and move said cutting element at a speed matching the speed of the web while in contact therewith, said operating means including a power rotated cam drum having a generally helical groove in the periphery thereof, said second drive mechanism including a follower wheel connected to rotate said rotary cutter and having angularly spaced followers thereon engageable in said groove.

4. A machine as defined in claim 3 wherein a portion of said groove extends circumferentially of the drum to provide a dwell in the rotation of said cutter corresponding to the dwell of said web.

5. A machine as defined in claim 3 wherein means are provided to adjust the angular position of said rotary cutter relative to said follower wheel and thereby adjust the position on the web at which said'openingsare cut.

6. A machine as defined in claim 3 including a take-up mechanism for selectively and positively adjusting the length of said web between said rotary cutter and said first drive mechanism, thereby to adjust the position at which the openings are cut.

References Cited UNITED STATES PATENTS 1,786,992 12/1930 Gronemeyer 83313 2,108,767 2/ 1938 Fitzgerald 83- 74 X ANDREW R. IUHASZ, Primary Examiner.