US3500726A - Machine for converting strip material into bags - Google Patents

Description

R. F- LENSE MACHINE FOR CONVERTING STRIP MATERIAL INTO BAGS Filed Feb. 20, 1968 ,Ma-rch 17, 1970 4 Sheets-Sheet 1 mavens-ro Rained 7Z1 ervJe fl fwyd' awd c n-ro awry-.1

no 0 no O m 9999 9 March 17, 1970 Filed Feb. 20, 1968 R. F. L-EN SE 3,500,726

MACHINE FOR CONVERTING STRIP MATERIAL INTO BAGS 4 Sheets-Sheet 5 MVEIOTOKJ @er pence M% W Vff lll RF. LENSE March 17, 1970 MACHINE FOR CONVERTING STRIP MATERIAL INTO BAGS Filed Feb. 20, 1968 4 Sheets-Sheet 4 MVEI mr on? {SeYLQe ymauld d1- Tcmtm K r w m p u in Fi United States Patent 3,500,726 MACHINE FOR CONVERTING STRIP MATERIAL INTO BAGS Robert F. Lense, Rockford, Ill., assignor to Riegel Paper Corporation, Rockford, III., a corporation of Delaware Filed Feb. 20, 1968, Ser. No. 706,882 Int. Cl. B31b 1/16.

US. Cl. 938 9 Claims ABSTRACT OF THE DISCLOSURE A packaging machine includes a swingable cutter for separating individual bags from a row of interconnected bags formed from a web of flexible material as the latter is advanced step-by-step along a predetermined path by a pair of rotatably driven feed rolls. The feed rolls are spaced just upstream from the cutter to provide effectual support for the flexible web as the cutter swings into engagement with the web to cut ofi the bags and, in addition, the rolls are adjustable along the path in unison with the cutter in order that the same small spacing may be maintained between the two when the cutter is shifted to an adjusted position along the path to operate on bags of a different size. An adjustable drive connection to the feed rolls rotatably drives the latter while permitting adjustment of the rolls along the path with the cutter.

BACKGROUND OF THE INVENTION This invention relates in general to a machine for convetting strip material and, more particularly, to a packaging machine for converting a strip or web of flexible material into a row of interconnected bags and for separating each individual bag from the row. In such a machine, rotatably driven feed rolls frictionally engage the row of bags to advance the latter endwise along a predetermined path past a cutter which periodically swings into engagement with the row to sever successively presented bags from the leading end of the row. Each time the machine is changed over to form bags of a different size, the cutter must be adjusted to a different position along the path and by an amount correlated with the change in the bag size so that, as the bags are cut from the row, they will be positioned properly for further handling.

SUMMARY OF THE INVENTION The primary aim of the present invention is to mount the feed rolls closely adjacent the cutter and to use the rolls to support the flexible row of bags as the cutter moves into engagement with the row, the support provided by the rolls being utilized with equal effectiveness regardless of the size of the bags. More specifically, an object of the invention is to support the feed rolls for adjustment along the path in unison with the cutter so that a fixed and relatively small spacing can be maintained between the feed rolls and the cutter in all adjusted positions of the latter.

A further object is to maintain a driving connection between the feed rolls and a drive module for rotating the rolls while still permitting selective adjustment of the rolls along the path with the cutter. The invention also resides in the novel construction and location of the drive module to simplify the establishment of a drive connection to the feed rolls.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings.

3,500,726 Patented Mar. 17, 1970 ice BRIEF DESCRIPTION OF THE DRAWINGS I FIGURE 1 is a fragmentary side elevation of a packagng machlne embodying the novel features of the present invention.

FIG. 2 is an enlarged fragmentary cross-section taken t substantially along the line 2-2 of FIG. 1.

FIG. 3 is an enlarged elevation of parts shown in FIG. 2.

FIG. 4 is an enlarged elevation of parts shown in FIG. 2 with certain elements being broken away and shown in section.

FIG. 5 is. an enlarged fragmentary cross-section taken substantially along the line S-5 of FIG. 2.

FIG. 6 is an enlarged fragmentary cross-section taken substantially along the line 6-6 of FIG. 2.

FIG. 7 is an exploded perspective view of parts shown in FIG. 6.

FIG. 8 is a perspective view of a part shown in FIG. 6.

FIG. 9 is a view similar to FIG. 6 with parts omitted for purposes of clarity.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings for purposes of illustration, the invention is embodied in a packaging machine of the type including a bag-making section 10 in which pouchtype bags 11 are formed from a continuous strip or web 13 of flexible material such as polyethylene film as the latter is advanced along a predetermined path. After the bags have been formed, they are transferred to a bag-filling section 14, are advanced along an extension of the path, and are filled with measured quantities of product. While the present invention is applicable equally well to a packaging machine adapted to advance the web and the bags with a continuous and uninterrupted motion, it herein is disclosed specifically in conjunction with a so-called intermittent motion machine of the type in which the web and the newly formed bags are advanced step-by-step with dwells occurring in the motion between successive steps.

In the present instance, the web 13 is unwound from a supply roll 15 (FIG. 1) and is drawn endwise beneath a triangular plow 16 supported on a suitable base or frame 17 and operable to fold the web upwardly along its longitudinal center line to form a pair of face-to-face strips disposed in vertical planes and connected at their lower margins by a fold 19. Mounted on the frame downstream from the plow is a sealing unit comprising two heated reciprocating bars 20 which are periodically shifted into engagement with the folded web to heat-seal the two strips together along longitudinally spaced lines extending crosswise of the web thereby to convert the latter into a row of bags 11 interconnected by side seals 21 and having open upper ends. The sealing bars are reciprocated by pneumatically operated rams 23 and are supported on a carriage 24 which is adjustable along the frame 17 to enable selective adjustment of the position of the sealing bars along the path. The web is advanced along the path through steps equal in length to the width of the ultimate bags with the sealing bars moving into engagement with the web during each dwell so that the horizontal distance w (FIG. 9) between successive side seals corresponds to the width of one bag. During sealing and just prior to the time the bags are filled, their upper edges straddle and are spread apart by elongated splitter bars 25 and 26 (FIGS. 1 and 6) extending above the bags along the bag-making and bag-filling sections 10 and14, respectively.

With continued advance of the web 13 after sealing, a cutting or severing unit 27 (FIGS. 1 and 2) disposed downstream from the sealing bars 20 separates successive bags 11 from the leading end of the row by cutting through the seals 21 midway between their side edges such that each seal 21 forms the trailing side seal of one bag and the leading side seal of the next succeeding bag. The cutter 27 is timed to move into engagement with the web as the latter dwells and is spaced downstream from the sealing bars by a distance equal to a multiple of the bag Width w so that, after each advance of the web, one side seal dwells alongside the cutter with the bag on the leading end of the web projecting downstream of the cutter and positioned in a transfer station 29 (FIGS. 6 and 9). Step-by-step advance of the web along the path during the folding, sealing and severing thereof is effected by a pair of power-driven upright feed rolls 30 and 31 frictionally engageable with opposite sides of the web and intermittently rotatable through arcs sufficient to advance the web through steps equal in length to the width of the bags being formed.

As each bag 11 dwells in the transfer station 29 during cut off, it is gripped along its leading edge preparatory to being transferred to the bag-filling section 14 of the machine. In this instance, the bag-filling section includes a conveyor 33 (FIGS. 6 and 9) formed by an endless chain adapted to be advanced stepby-step in a horizontal plane and trained around a sprocket wheel 34 located in the transfer station beneath the path of the web 13. Upright carrier bars 35 are attached to and spaced equally along the conveyor and each supports two vertically ;paced clamps 36 for gripping the bags 11. The movement of the conveyor is timed such that one pair of clamps iwells in the transfer station in an open condition to receive the leading edge of the leading bag as the latter advances past the cutter 27. The clamps then are closed 3y an operating mechanism 37 (FIG. 1) so as to grip and hold the bag while the cutter separates the bag from :he web. Thereafter, the conveyor advances the cut-off bag :hrough one step toward a filling station where the bag s filled with a quantity of product and, during such adlance, another pair of clamps is presented to the transfer itation to receive and grip the next bag passing by the :utter. The horizontal spacing a (FIG. 9) between the :utter 27 and the clamps 36 dwelling in the transfer atation corresponds approximately to the width w of the Jags being formed in order that each leading bag will be -eceived in a pair of clamps as the bag is severed from he web.

Often, the same packaging machine will be used to form and fill a series of bags 11 of one width and then will be :hanged over to form and fill a series of bags of a diferent width. To change over the machine to run bags vhich are wider or narrower than those of a preceding 'un, the arc of rotation of the feed rolls 30 and 31 is ncreased or decreased such that a length of web equal the new width of the bags is advanced during each .tep. Since the side sealing bars 20 operate in the interval Ietween the steps, the horizontal distance w between suczessive side seals 21 will increase or decrease by a coresponding amount thereby resulting in the formation of vider or narrower bags. In addition to adjusting the arcs hrough which the feed rolls are rotated, it is necessary 0 adjust the cutter 27 along the path to increase or derease the horizontal spacing a between the cutter and he conveyor 33 by an amount correlated with the new ag width in order that the leading edges of the new bags vill be presented to the clamps 36 as the bags advance ast the cutter. Accordingly, the cutter is mounted ad- Jstably for movement toward the conveyor when the machine is changed over to run narrower bags and for novement away from the cutter when the machine is hanged over to run wider bags. After the cutter has been djusted, the side sealing bars 20 are adjusted along the ath by a corresponding amount to change the spacing IetWeen the sealing bars and the cutter to a multiple of he new bag width. By making such adjustments, the pe i s m chine illust ated be ch ng d o e o f bags which range in width from as low as two inches to as wide as twelve inches.

In its primary aspect, the present invention contemplates mounting the feed rolls and 31 at a location which is spaced just a very slight distance upstream from the cutter 27 in order to use the feed rolls to support the flexible web 13 as the cuter moves into engagement with the web to cut off each leading bag 11. Moreover, the feed rolls are adjustable along the path in unison with the cutter and, as a result, the spacing between the feed rolls and the cutter is maintained at an optimum value and is not increased when the position of the cutter is adjusted to change the machine over to run bags of a different width. In general, these ends are achieved by mounting the feed rolls and the cutter side-by-side on a common adjustable support 40 and by establishing an adjustable drive connection to the feed rolls so that rotative drive may be transmitted to the rolls in all of their adjusted positions.

More specifically, the support 40 (FIGS. 2, 6 and 8) carrying the cutter 27 and the feed rolls 30 and 31 comprises a flat plate or platform which is supported for adjustment longitudinally of the path on the top 41 of a cabinet 43 forming part of the frame 17, the cabinet being located downstream of the sealing bars 20 near the downstream end of the bag-making section 10. The platform 40 overlies and covers an opening 44 formed in the top of the cabinet and is guided for endwise sliding on the cabinet by a series of rolls 45 (FIGS. 2 and 4) engageable with the side edges of the opening and journaled on vertical pins 46 which depend from the platform.

The cutter 27 is mounted on the upper side of the platform 40 and herein includes a swingable blade 47 (FIGS. 2 and 5) movable transversely of the folded web 11 and across a fixed blade 49 with a scissors action as the web dwells after having been advanced between the two blades when the latter are separated. The swinging blade 47 is held under the pressure of springs 50 against one side of the upper end portion of an upright lever 51 (FIGS. 2, 5 and 7) of T-shaped cross-section, the lower end portion of the lever projecting downwardly into the cabinet 43 through a hole 53 (FIG. 8) formed in the platform 40. Near its lower end, the lever is pivoted for back and forth swinging on a horizontal pin 54 (FIG. 7) projecting axially from a circular disk 55 which is fastened to one end wall of an underslung case 56 anchored to the underside of the platform and housed within the cabinet in vertical alinement with the top opening 44.

To swing the movable blade 47 relative to the fixed blade 49, an air cylinder '57 (FIG. 2) is attached to'the case 56 and includes a reciprocating plunger 58 pivotally connected to the lower end of the lever 51 and operable to rock the latter and the blade 47 about the pin 54 in response to the admission of pressurized air into alternate ends of the cylinder under the control of an electricallyactuated valve (not shown). Swinging of the movable blade 47 carries its cutting edge across the cutting edge of the stationary blade 49 to shear the web 13 along one of the seals 21, the latter blade being positioned to coact with the cutting edge of the swinging blade and being fixed to one edge of a plate 59 (FIGS. 2 and 5) upstanding from the platform 40. The web is guided between the two blades and is pressed against the cutting edge of the fixed blade during cut off by a spring metal strip 60 .(FIG. 5) extending lengthwise of the blades adjacent the cutting edges.

In response to swinging of the movable blade 47, a flying splitter 61 (FIGS. 2, 3 and 6) is swung upwardly from a normal position disposed between the upper edges of the folded web 13 to a raised position disposed out of the way of the swinging blade. The flying splitter is located within a gap defined by adjacent ends of the splitter bars 25 and 26 and is suspended from a shaft 63, jo r l d t ma n a o zonta o]; p ate 64 s pp t! above and extending parallel to the platform 40. As the web advances, the flying splitter holds the upper edges of the web spread apart as the latter passes between the blades 47 and 49 and through the gap between the splitters 25 and 26. During each dwell when the movable blade is swung through its cutting stroke, the splitter is rocked upwardly and out of the path of the blade by a crank 65 (FIG. 2) fastened to the lever 51 and connected by a link 66 to a crank 67 on the shaft 63.

As shown most clearly in FIGS. 1, 2 and 6, the feed rolls 30 and 31 are located on the upstream side of the cutter 27 and are journaled for rotation at their upper ends in bearings (not shown) mounted on the same top plate 64 which carries the flying splitter 61. At their lower ends, both rolls are journaled in bearings 70 (FIG. 6) on the platform 40, the lower ends of the rolls including extended shafts 71 (FIG. 7) projecting downwardly through holes 73 (FIG. 8) in the platform and operably connected to drive gearing 74 housed within the case 56.

The feed rolls 30 and 31 are spaced upstream from the cutter 27 a distance 12 (FIG. 9) which is only far enough to establish sufiicient clearance between the two to allow manual threading of the web 13 through the rolls and the blades 47 and 49 at the start of a run, the spacing b herein being approximately 1 /2 inches. With the feed rolls located closely adjacent the cutter, the roll 31 provides effective lateral support for the web as the blade 47 swings through its cutting stroke and into engagement with the web to cut off each bag 11. Accordingly, lateral deflection of the web under the force of the blade 47 is reduced thereby resulting in fewer ruined bags and in more trouble-free operation of the machine with less down time caused by a fouled web. Since the feed rolls are mounted on the platform 40 and are adjusted along the path with the cutter when the position of the latter is changed, the spacing between the rolls and the cutter always remains fixed at the optimum value b thereby utilizing with maximum effectiveness the lateral support provided by the rolls regardless of the position of the cutter and regardless of the width of the bags being formed.

Quick and simple adjustment of the position of the platform 40, the cutter 27 and the feed rolls 30 and 31 is facilitated by an actuator in the form of a lead screw 76 (FIGS. 2 and 7) which is threaded into a nut 77 fastened to the forward side wall of the case 56. The screw extends through and is mounted rotatably in the front end wall of the cabinet and is adapted to be turned by a hand crank 79 (FIG. 9) on one end of the screw. Rotation of the crank causes the nut to translate along the screw thereby sliding the platform 40 endwise on the cabinet 43. A pointer 80 (FIG. 2) preferably is carried on the platform near the forward side edge thereof and runs along a scale on the top of the cabinet 43 to indicate the position of the cutter 27 along the path.

Intermittent and unidirectional rotative drive for the feed rolls 30 and 31 is produced by a power module housed within the cabinet 43 and including an electric motor 81 (FIG. 6) connected by an endless belt 83 to a gear box 84 having an output shaft 85 which mounts a variable-throw crank 86. The latter is coupled by a pitman 88 to a second crank 89 which is fast on a rotatable motion-transmitting connection 90. Advantageously, the latter is formed by two relatively adjustable parts, namely, an internally splined sleeve 91 (FIGS. 6 and 7) and an externally splined shaft 93 slidably telescoped into the sleeve. The splined sleeve 91 is journaled in the front end wall of the cabinet 43 and mounts the crank 89. The splined shaft 93 is rotatably driven by but axially adjustable relative to the sleeve 91 and is coupled to a shaft 93a by means of an electro-magnetic clutch 94, the shaft 93a being connected to the gearing in the case 56 to drive the feed rolls 30 and 31. Both the clutch 94 and the shafts 93 and 93a are supported from the underside of the platform 40 and are adjustable with the platform. The sliding fit between the splined sleeve 91 and the splined shaft 93 enables quick and easy adjustment of the feed rolls along the path with the platform 40 while still maintaining a driving connection from the motor 81 and the sleeve to the shaft and the feed rolls.

With the foregoing arrangement, the pitman 88 reciprocates up and down through one cycle in response to rotation of the output shaft 85 and the crank 86 through one revolution and acts through the crank 89 to oscillate the sleeve 91 and the shaft 93 back and forth about their axes. On the downstroke of the pitman, the direction of rotation of the shaft 93 corresponds to that necessary to rotate the feed rolls 30 and 31 in a direction advancing the web 13 and, during the downstroke, the clutch 94 is energized to transmit the movement of the shaft 93 to feed the rolls to rotate the latter. Before the output shaft 85 completes one half revolution to start the pitman 88 through its upstroke, the clutch is deenergized to prevent the shaft 93 from driving the feed rolls reversely.

In setting up the machine, the throw of the crank 86 is adjusted to cause rotation of the feed rolls 30 and 31 through arcs somewhat greater than are necessary to advance the web 13 through steps equal in length to the width of the bags to be run. As the pitman 88 starts through its downstroke, the clutch 94 is energized to cause rotation of the feed rolls and advancement of the web. Each time the web moves through a step of desired length, a photo-electric scanner 95 (FIG. 6) supported alongside the path on the top plate 64 detects one of a series of targets 96 (FIG. 9) pre-printed on the web and spaced from each other in accordance with the width of the bags. In response to such detection, the scanner produces an electric signal to energize an electro-magnetic brake 97 (FIGS. 6 and 7) which acts on the shaft 93a to arrest further rotation of the feed rolls and to stop movement of the web precisely upon completion of a step of desired length. The clutch slips for a short time while the brake is energized and then both the clutch and the brake are de-energized simultaneously before the pitman 88 starts on its upstroke to turn the shaft 94 in the opposite direction. As the web dwells, a one-way clutch 99 (FIG. 6) connected to the feed rolls positively prevents any reverse rotation of the rolls tending to result from the force exerted by the tensioned web.

In addition to rotating the feed rolls 30 and 31, the electric motor 81 drives a rotatable cycle shaft 100 (FIG. 6) which is operable both to advance the conveyor 33 and to actuate many operating mechanisms in the bagfilling section 14. As shown in FIG. 6, the cycle shaft is coupled to a second output shaft 101 of the gear box 84 and is driven in timed relation with the output shaft 85 thus synchronizing the cycle shaft with the advance of the web. Rotatable with the cycle shaft 100 and housed within the cabinet 43 are two cams 103 which sequentially open and close limit switches 104 at timed intervals as the cycle shaft rotates. One of the switches controls the energization and de-energization of the clutch 94 while the other switch controls the flow of air to the pneumatic rams 23 for the side sealing bars 20. Through a chain 105, the cycle shaft synchronously rotates a sequence shaft 106 (FIGS. 1 and 6) that carries a large number of cams 107 which operate switches (not shown) for controlling the cutter actuator 57 and various operating mechanisms in the bag-filling section 14.

From the foregoing, it will be apparent that the feed rolls 30 and 31 support the web 13 with equal effectiveness irrespective of the position of the cutter 27 and the width of the bags 11. The drive module including the motor 81 is compactly housed within the same cabinet 43 upon which the supporting platform 40 is adjustable, and is advantageously located beneath the feed rolls near the downstream end of the bag-making section 10 so that the adjustable drive connection 90 can be established between the motor and the rolls in a relatively simple manner.

I claim as my invention:

1. In a machine for converting strip material, the combination of, a frame, a support on said frame, a feed roll on said support for frictionally engaging the strip and intermittently rotatable through a selected arc to advance the strip step-by-step along a path through steps of predetermined length with dwells between successive steps, a cutting member mounted on said support on one side of said feed roll and movable into engagement with the strip while the latter is dwelling to cut off the leading end portion of the strip, means mounting said support adjustably on said frame for selective movement of said feed roll and said cutting member in unison along said path, a rotatable drive shaft supported on said frame, and an adjustable connection between said shaft and said feed roll for transmitting motion of said shaft to said feed roll while leaving the latter free for adjustment with said support relative to said shaft and said frame.

2. A machine as defined in claim 1 in which said cutting member is located just downstream from said feed roll and is spaced a fixed distance along said path from said roll regardless of the length of the portion cut off from the leading end of said strip.

3. A machine as defined in claim 1 in which said coniection comprises an internally splined part and an externally splined part slidably telescopcd into said internally splined part, one of said parts being carried by and adjustlble with said support and being operably coupled to ;aid feed roll, the other of said parts being operably :oupled to said drive shaft and being mounted on said frame.

4. A machine as defined in claim 3 further including in electrically-actuated clutch carried on and adjustable with said support, said clutch being coupled between said feed roll and the part carried on said support and being ;electively engageable and disengageable to continue and liscontinue the transmission of motion from the latter )art to said feed roll.

5. A machine as defined in claim 1 further including in actuator connected between said frame and said suport and selectively operable to move the latter relative said frame and along said path.

6. In a machine for converting strip material, the comination of, a frame, a support on said frame, a feed 011 on said support for frictionally engaging the strip and rotatable to advance the strip along a predetermined )ath, a cutting member mounted on said support down- :tream from said feed roll and periodically movable into :ngagement with the strip to cut off the leading end JOItiOl'l of the strip, means mounting said support adjustably on said frame for selective movement of said feed roll and said cutting member in unison along said path, a rotatable drive shaft supported on said frame, and an adjustable connection between said shaft and said feed roll for transmitting rotation of said shaft to said feed roll while leaving the latter free for adjustment with said support along said path and relative to said shaft and said frame.

7. In a packaging machine for separating individual bags from a strip of interconnected bags advanced along a predetermined path, the combination of, a frame, a support on said frame, a pair of rotatable feed rolls on the upper side of said support and frictionally engageable with opposite sides of the strip to advance the latter along said path, a cutter pivotally mounted on said support and spaced a predetermined distance downstream from said feed rolls, means for periodically swinging said cutter into engagement with the strip to cut off the leading bag from the strip, means mounting said support adjustably on said frame for selective movement of said feed rolls and said cutter in unison along said path thereby to enable adjustment of the position of said cutter while maintaining the latter spaced said predetermined distance from said feed rolls, gearing mounted on the underside of said support for adjustment with the latter and operable when driven to rotate said feed rolls, a drive motor, a drive shaft journaled on said frame and connected for rotation by said motor, and a splined connection between said shaft and said gearing for driving the latter and said feed rolls in response to rotation of said shaft while leaving the feed rolls free for adjustment with said support.

8. A packaging machine as defined in claim 7 further including a sealing unit mounted on said frame upstream from said feed rolls, said drive motor being positioned beneath said feed rolls and being downstream of said sealing unit.

9. A packaging machine as defined in claim 8 in which said frame includes a cabinet located downstream from said sealing unit; said support being mounted on and adjustable along the upper side of said cabinet; and said gearing, said connection, said shaft and said drive motor being housed within said cabinet.

References Cited UNITED STATES PATENTS 2,854,899 10/1958 Bauder et al. 93-43 3,263,542 8/1966 Langwell 83241 TRAVIS S. McGEHEE, Primary Examiner U.S. Cl. X.R. 83-209, 241

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