US2636732A

US2636732A - Web feeding method and means for container forming apparatus

Info

Publication number: US2636732A
Application number: US17973A
Authority: US
Inventors: Stanley R Howard
Original assignee: Pneumatic Scale Corp
Current assignee: Pneumatic Scale Corp
Priority date: 1948-03-30
Filing date: 1948-03-30
Publication date: 1953-04-28
Anticipated expiration: 1970-04-28

Description

April 8, 1953 s. R. HOWARD 2,636,732

WEB FEEDING METHOD AND MEANS FOR CONTAINER FORMING APPARATUS Filed March 30, 1948 4 Sheets-Sheet l 0 IN V EN TOR. jfqn ey E f/flwa' c/ BY ATTORNEY April 28, 1953 s. R. HOWARD 2,636,732

WEB FEEDING METHOD AND MEANS FOR CONTAINER FORMING APPARATUS Filed March 50, 1948 4 Sheets-Sheet 2 INVENTOR.

J JM ehcm' ATTORNEY S. R. HOWARD ING ME April 28, 1953 2,636,732 WEB FEED THOD AND MEANS FOR CONTAINER FORMING APPARATUS 'Filed March 30, 1948" 4 Sheets-Sheet 3 INVENTOR. Jfd/ /e I? fi-wm B Y $5.1 CL-M' ATTORNEY Apnl 28, 1953 s. R. HOWARD 2,636,732

A WEB FEEDING METHOD AND MEANS FOR CONTAINER FORMING APPARATUS Filed March 30, 1948 4 Sheets-Sheet 4 IN V EN TOR. FYE? 7 J7dn/e v I? %wdrt-/ A TTORNEV Patented Apr. 28, 1953 WEB FEEDING METHOD AND MEANS FOR CONTAINER FORMING APPARATUS Stanley R. Howard, Milton, Mass, assignor to Pneumatic Scale Corporation, Limited, Quilter/3; Mass, a corporation of Massachusetts Application March 30, 1948, Serial No. 17,973

16Claims. (Cl.271--2.6)

This invention relates to a packaging machine and particularly to a bagging machine, such as a tea-bagging machine.

In general the object ofthe invention is to provide a novel and improved packaging machine wherein a printed web of flexible shcet material, such as heat scalable printed paper, is utilized to produce successive filled and sealed containers in a rapid, efficient and commercially acceptable manner and wherein novel provision is made for controlling the feeding of the webto effect regis tration of the successive printed sections of the web with relation to the container forming mechanisms within tolerances permitted by the commercial acceptability of the packages produced. In its preferred embodiment the invention is embodied in a tea-bagging machine.

With this object in view and such others as may hereinafter appear, the invention consists in the packaging machine, and particularly in the tea-bagging machine, and in the various structures, arrangements and combinations of parts hereinafter described and particularly de in the claims at the end of this specification,

In the drawings illustrating the preferred embodiment of the invention, Fig. lis a side elevation of a tea-bagging machine embodying the present invention; Fig. 2 is a front elevation of the lower portion of the machine shown in Fig. l and illustrating the web advancing grippers; Fig. 3 is a plan view of the web advancing grippers shown in Fig. 2; Fig. t is a detail view in side elevation of web unwind ng and releasing mechanism and control mechanism associated therewith; Fig. 5 is a detail view in cross section taken on the line 5-5 of Fig. l; 6 is a front elevation of a completed tea bag and adjacent sections indicating the of the predetermined web advance, the advance with the corrective stroke relative to the bag length or to the distance between the printed indicia on the web; and "I is an elec doe-l wiring diagram for the web feed control mechanism.

In general the invention contemplates a packaging machine, and particularly a bag forming, filling and scaling machine, wherein novel and improved web feeding control mechanism enables the machine to operate upon a printed web and to eliect registration of successive printed bag forming sections of the we with respect to the bag forming, filling sealing mechanisms with permissible tolerances. Bri fly provision is made for detecting a variation of the web from the. maximum permitted tolerance during the feeding thereof. and for effecting a. corrective hula,

feeding during the same cycle of operation that the detection is mad so that until a further detection indicates the need for another correction the web is fed to effect registration as above stated within the tolerances permitted.

Referring now to the drawings, the present invention is illustrated as embodied in a commercial machine for making individual filled and sealed containers such as tea bags, from an elongated web or strip or" paper in accordance with the method disclosed in the United States patent to Patterson, No. 2,272,530, issued February 10,

1942, and in general comprises an improvement in the apparatus disclosed in the United Sta es patent to Patterson, No. 2,385,229, issued September 1.3, 1945. As herein shown, such machines may be constructed in duplex form for simultaneously producing two strips of connected and filled containers and for severing the strips through sealed portions thereof to form individual tea bags. 1

In the operation of such a machine and, as illustrated in l, a web of heat scalable paper it is Withdrawn from a supply roll l2 thereof advanced over forming mechanism It which operates to fold the web longitudinally along a medial line to bring together the two half sections of the web preparatory to forming a strip of connected bag sections it. The paper is drawn over the forming mechanism it by vertically and horizontally reciprccable gripping and advancing mechanism operative to advance the strip sub stantially one bag length each cycle of operation and to present the strip in operative relation to sealing mechanism indicated generally at 22 arranged to apply heat and pressure to seal the strip simultaneously along a transverse zone 2% and an adjacent longitudinal zone 25 during each sealing operation to form a series of connected bag sections closed on one side by the folded edge 28 and heat sealed along the remaining side and at the top bottom.

In the illustrated embodiment of the invention provision is made for first unwinding the paper web from the supply roll it and then releasing a predetermined length of the unwound web to be advanced by the gripper mechanism 20, and, as herein shown, the material isarranged to be unwound from the supply roll it by unwinding and releasing indicated generally at which includes an idler roll it for guiding the web to the bag forming mechanisms. The supply roll it may be provided with suitable retarding means, such as a friction bearing indi' cated at 5 I, for preventing inadvertent unwinding of the web material and to maintain the web relatively taut between the supply roll and the unwinding mechanism.

Provision is also made for depositing successive charges of the commodity into successive of the uppermost bag sections as they are being formed, by feeding mechanism indicated generally herein at 30, the feeding mechanism operating in timed relation to the Web advancing mechanism and the sealing mechanism 22. In the operation of the machine, the open top of a bag section which has been provided with a charge of the commodit during one cycle of operation is closed during a succeeding cycle. Thereupon, the strip is intermittently advanced to severing mechanism, indicated generally at 32, which operates to sever the strip through successive transverse sealed portions 24 to form individual filled and sealed bags.

The machine illustrated and described in the Patterson Patent No. 2,385,229 above referred to was particularly designed for producing paper tea bags made from a web of plain, unprinted heat sealable paper, and such machines are at the present time in extensive successful commercial use. However, when printed webs are used in a machine having a linear web advancing mechanism arranged to advance the web a fixed length corresponding to a predetermined bag length it is difficult to maintain correct registration of successive printed bag sections with the bag forming instrum'entalities since, in practice, the sections may vary due to inaccuracies in printing, to variations in expansion and contraction of the web due to atmospheric conditions, stretching of the web during withdrawal, or possible slippage of the web. Thus, in the operation of such prior machines on a printed web any slight variations in the length of the printed sections are cumulative so that eventually the web departs from proper registration with the bag forming and severing mechanisms.

In accordance with the present invention provision is made for varying the linear advance of the web to compensate for the variations in the printed web, and, in the illustrated embodiment of the invention provision is made for unwinding and then normally releasing a predetermined length of Web slightly less than the predetermined bag length to be advanced by the gripper mechanism each cycle of operation, the grippers being arranged to travel a distance slightly more than the predetermined bag length and to slip on the web when the predetermined lesser amount of web released has been advanced to its full extent so that the advance of the web during each normal cycle of operation is slightly less than the predetermined bag length. Provision is further made for efiecting release of a slight additional increment of the web to permit the Web to be advanced the full stroke of the grippers by control mechanism responsive to the passage of the registration marks at a predetermined time in the Web advancing cycle of operation, thus permitting the web to be advanced a distance slightly more than the predetermined bag length when a-deviation from a predetermined position of a registration mark occurs thereby providing in eiTect a correction in the linear advance of the web during the same cycle of operation in which such deviation is detected by the control mechanism.

As herein shown, each web gripping and advancing mechanism 20 includes a pair of opposed

cooperating grippers

40, 42 mounted to be hori 4 zontally reciprocated into and out of gripping ngagement with the web, and, to be vertically reciprocated to advance the Web each cycle of operation. In the present embodiment of the invention, the gripper operating mechanism may be initially adjusted to effect a linear stroke of the grippers capable of advancing the web a distance slightly more than the predetermined bag length or distance between successive substantially equally spaced registration marks 44 on the web, and, the grippers are yieldingly engageable with the web so as to permit slippage near the end of the advancing stroke when the shorter length of Webbing is released but effective to ad- Vance the web the full distance of the linear stroke of the grippers when an additional length of webbing is released during the advancing movement.

In general, the control mechanism includes a photo-sensitive detector, indicated generally at it, arranged to cooperate with the spaced registration marks i l during the advancing cycle of operation; a timing switch 48, see Fig. 7, arranged to render the detector operative at a predetermined time in the Web advancing cycle; web unwinding and releasing means, indicated generally at 2th; and a solenoid operated latch member 59 operative to permit release of an additional increment of the web when actuated by the detector mechanism. The

gripper members

10, 42 are arranged to yieldingly engage the web during the advancing stroke with suilicient firmness to effect positive advancement of the loose Web unwound and, released by the mechanism 2013, yet permitting slippage of the grippers when a length of web less than the full stroke is released.

In practice, the photo-sensitive detector may be disposed relative to the web so that the light beam image is concentrated on the edge of the web at a point approximately halfway between two marks 3 5 when the web is at rest, as illustrated in Fig. 1. Thus, during intermittent advancement of the web the light beam may be intercepted by a mark at about the halfway point in its advance, as illustrated in Fig. '7. The detector unit herein illustrated is arranged to be excited to effect an additional increment of release of the web only when the light beam is intercepted by a, mark during the scanning period, that is, when the circuit is closed by the timing switch it and then only when the beam is cut oil or intercepted by the leading edge of a rapidly passing mark. If the beam falls di rectly on the marl: when the switch 48 is closed, no correction in the web feed is effected, and likewise, if the beam falls on the mark and the mark then passes by so that the beam then falls on the relatively lighted background of the Web during the scanning neriod, no correction is made.

In the operation of the apparatus, assuming that the average package length is approximately 2 inches, for example, successive predetermined web releasing and advancing movements are arranged to advance the web about of an inch less than the predetermined bag length, or about 2 5';- inches each cycle of operation so as to effect a gradual and cumulative rising or creeping up of the marks 44 relative to the light beam until a point is reached where the beam is intercepted by a mark moving therepast. When this occurs, the web releasing mechanism is rendered operative to release an additional increment of web material so that the web is advanced the full stroke of the grippers, the net advance of the web being about of machine frame.

an inch more than the predetermined length of a. bag section or a total of a} inches. Thus, it willbe seen that the web advancing movement is either increased or decreased relative tothe predetermined bag length, between the permitted limits or variation thereof, so that in operation substantially correct registration of successive bag sections with the container form" ing mechanisms is obtained.

Referring now to Figs. 1 and 2 for a more detailed" description or the web releasing and advancing mechanisms, as therein shown, op posed grippers tll, 42 are arranged to be horizontally reciprocated in brackets 52, 5t respective y, the latter being adjustably clamped upon vertical rods 56-, 53 supported for vertical ciprocation in suitable bearings provided in the The rods 56, 58- are arranged to be vertically reciprocated in timed relation to, the operation of the bag forming mechanisms by a cam lit mounted fast on the main shaft 166, and, as herein shown, provision is made for initially adjusting the effective strobe of the cam in order to adjust-the linear advance of the. grippers with relation to the predetermined spacing of the bag sections of the web. The rods 5b., 5% are secured at their lower ends to a. pair or yoke shaped tie pieces fit onlyone of whichis shown, the illustrated tie piece having a central slotted portion M for cooperation. with a slide block 56? mounted on one end of an eccentric stud 63 carried in a lever it fast on a rocker shaft it, the eccentric stud being rotatably adjustable in the lever it. The eccentric end of the stud all is provided with a roller hi cooperating with the fixed cam of the cam be, as clearly shown in 5.

With this construction it will be seen that by rotary adjustment of the eccentric stud 58 the. effective length of the lever arm it may be varied, rotary adjustment in one direction operating to increase the distance from the center of the rocker shaft 12 to the center of roller M: to thus. decrease the effective stroke, and, rotary adjustment in the opposite direction operating to decrease the distance from the center of the rocker shaft to the center of the roller to thus increase the eiiective stroke. Thus, the linear movement of the gripper units may be initially adjusted so as to be capable of effecting d a linear advance of the web a distance slightly more than the average spacing between successive. marks 44., It will be understood that the gripper carrying brackets 52, 5t be ad- .i-usted on theirrespectiverods 5d,. 58, to align the cooperating gripper units it, at for cooperation with successive transverse sealed portions 24 of the web.

While the above description has been confined to. the operation of one pair of cooperating gripper units. 40, 52 for advancing a web of container forming material into operative relation to; the package forming instrumentalities, it will. be understood that. in the duplex machine herein illustrated, an identical and simultaneously operating pair or gripper units Mill, 42G are'carried by the brackets 52, it respectively, as. illustrated in. Fig. 3, the brackets being also adjustably supported upon vertical rods etc, 53% arranged to be vertically reciprocated by the cam fill through similar con nections including a lever arin fast on the rocker shaft 72 so that in operation each pair of grippers: are simultaneously operated to cause the webs to be advanced concurrently into operative relation to their respective: containeriormina; filling and severing mechanism.

As illustrated in Figs. 2 and 3, each gripper unit it, 21 and their corresponding units 40B, tit are supported for horizontal reciprocation upon individual rods 76 slidingly carried in the brackets 52, 5t, each. rod being provided with a coil spring 18 interposed between a. portion of its supporting bracket and a collar to; ad- 'ustably. secured to the rod, the springs being arranged to urge the grippers inwardly into. cooperating engagement with their opposing grippers and their respective container forming webs; The rods It of each. unit are joined at. their outer ends by a tie piece 82' and each tie. piece carries a roller 84 arranged to. cooperate. with elongated cams it secured to vertical cam. shafts 8t, 3t respectively. I'hus, in the operation of the machine, the gripper units it, tilt and 42, 426i are horizontally reciprocated simultaneously into and from engagement with the webs. the spring 18 effecting a yielding engagementtherewith and the cams." 85. operating to positively separate the grippers. The springs ill may be adjusted so as to provide .a suficiently' firm grip as to effect a positive advance of the web material freed from the supply roll [2 by the unwinding and releasin mechanism tilt and yet capable of slipping on the web when. an amount less than the full stroke of the. grippers is released. The vertical cam shafts 88,. are arranged to be rotated from the main cam shaft lull by con.- nections including bevel gears 92, 9a to the vertic-a1 haft 553, bevel gears 96, 98 to a horizontal cam shaft 99 and a second set or similar bevel gears to the vertical shaft. 90. As herein shown, one gripper member, All, may be yieldingly mounted to provide a more accurate control of the gripper pressure, the gripper member being provided with a pair of pins it], Hi3 slidingly carried in a block [05 secured to the end or the rod iii. Springs It! coiled about the pins and interposed. between the gripper member and the block are arranged to yieldingly urge the gripper it toward its opposing gripper, each pin iiii, Hi3 being provided with a nut Hi9 on its outer end for adjustably limiting the'inovement in this, direction.

As above, stated, the web. unwinding and releasing mechanism, indicated generally at 2%, is arranged to normally release a length of web slightly less in length than the predetermined bag section to be advanced by the gripping and advancing mechanism iii into operative relation to the forming and filling mechanisms, and, to release an additional increment of the unwound web material when actuated by the cc11- trol mechanism it, the additional material being also advanced by the gripping mechanism it to provide in effect a corrective feeding movement during the same cycle or operation in which a deviation from a predetermined po"""'on oi the web is detected. [is best shown in 4, the web unwinding and releasing mechanism comprises a cam operated rocker lever its pivota"y mounted at iii and having a roller Hi2 carried thereby which is arran to engage the Web and to control. the length of web material unwound released each cycle of operation. [is herein shown, the web iii unwound from the supply roll is arranged to pass over idler roll under the roller 82, and then over the guide roll l'l, the unwound portion of the web forming a loop iilil. In operation, the downward rocking movement of the lever ill-i eiiectsunwinding of a predetermined length of web material each cycle of operation, and, upward rocking movement of the lever is arranged to release a predetermined length of the unwound material by leaving the loop 1% free to be advanced by the

grippers

40, 42. The unwinding and releasing lever I is limited in its downward movement by its operating cam and connections therebetween to effect a positive limit of unwinding movement, and, is normally limited in its upward movement by the solenoid operated latch member 59 arranged to engage the outer end of the lever I00.

The downward or unwinding movement of the rocker lever we may occur during the stationary period of the web and at a time when the sealing members 22 are in engagement with the web, and the upward or releasing movement of the rocker lever [t0 may occur immediately thereafter or just prior to the web advancing movement. In order to prevent additional unwinding of the web material from the supply roll I2 during the web advancing movement, a spring pressed clamp t id may be provided which is arranged to cooperate with the idler roll Hit to clamp the web immediately after the unwinding operation, the clamp being released at the end of the web advancing movement when the sealer members 22 engage the web to permit a succeeding length of web to be withdrawn from the supply roll, the sealing members 22 preventing upward or retracting movement of the web during this time.

As illustrated in Fig. 1, the lever Iiiil is arranged to be rocked to effect unwinding and releasing of the web by a cam I i2 fast on the horizontal cam shaft 99 and through connections including a cam roll Ilt carried on the lower end of a vertical rod H6 mounted to be reciprocated in a bearing IIB, the rod lit being urged downwardly to hold the roll II i against its cam by a spring I interposed between a portion 01. the bearing and a collar I22. The upper end of the rod H5 is provided with a tie piece Hi l which carries two separate rods I26, i228 pivotally carried in the ends thereof for cooperation with opposed unwinding and releasing mechanisms of the duplex machine. Each rod I26, I28 is provided with a yieldable connection in which the rod is arranged to pass through a swivel l 30 carried by the lever m0, the rod being provided with a nut I at its outer end for engagement with the top of the swivel to positively urge the lever 80 downwardly. A coil spring 332 is interposed between the underside of the swivel and the connected end of the rod to permit the lever I00 to be yieldingly rocked upwardly to release the loop I06 of unwound material. Adjustment of the downward limit of rocking movement of the lever I08 may be effected by adjustment of the nut I 3|.

In the operation of the machine, the lever Iiiii is normally engaged by the latch member 59 to limit the amount of the web released to an amount slightly less than the length of a predetermined bag section. However, when the control mechanism detects a deviation from a predetermined position of the web during the advancing movement, the solenoid operated latch is arranged to unlock the arm I00 whereupon the arm will be rocked upwardly an additional increment of the loop tilt by virtue of the yieldable connection, the arm being adjustably limited in its additional upward rocking movement by a set screw I34, the additional amount released being sufficient to provide a net length of web released slightly more than the predetermined bag length. As herein shown, the normally engaged latch member 50 is pi-votally mounted at I36 and is provided. with an arm I38 connected by a link I40 to the armature of a solenoid I42. A spring I44 connected to the arm I38 is arranged to hold the member 50 in latching position until the solenoid is actuated by the control mechanism.

In the illustrated embodiment of the invention, the spring pressed clamp H0 is carried by an arm lit pivotally mounted on the guide roll shaft M3 and is arranged to be actuated by the unwinding and releasing cam 552 through connections including a cam roll ital] carried by a lever I52 fast on a rocker shaft I52. The rocker shaft I5! is connected to the clamping units of opposed unwinding and releasing mechanisms of the duplex machine to effect simultaneous operation thereof, and, as illustrated in Fig. 1, one arm I58 of a bell crank fast on the rocker shaft IE4 is connected by a link 5513 to a corresponding arm Itl of a bell crank pivotally mounted on a shaft m2. The second arm IE5 of each bell crank is connected by similar links I66 to corresponding arms I ls which carry the spring pressed clamps I It. With this construction it will be seen that when the cam i I2 eifects upward rocking movement of the arms I00 to release a portion of the loop Hi3 to be advanced by the grippers, the webs will be clamped between the idlers Iii-t and the clamping members M0 to prevent unwinding of material from the supply roll I2, and conversely, when the arms I00 are permitted to be rocked downwardly by the cam H2 to effect unwinding of the webs from their supply rolls, the clamping members I It will be released from clamping engagement. A spring i5? connected to the arm 55% is arranged to hold the roller ltd against the cam. It will be observed that in operation the loop Hi0 contains an amount of material in excess of that required for either the normal or corrective releasing and advancing movements and that an additional length is unwound from the supply roll each cycle of operation equal to the length released and advanced during the preceding cycle so as to maintain a uniform supply of material in the loop at the start of each releasing operation.

From the description thus far it will be observed that the printed bag forming web I0 having spaced registration marks 4d thereon, cor-- responding to the length of successive bag sections, may be intermittently advanced a distance slightly less than the predetermined distance between registration marks cycle of operation although the linear stroke of the gripping and advancing mechanism is sufiicient to provide an advancing movement slightly more than such distance, the grippers being arranged to permit slippage of the web when the normally lesser amount of web is released. It will also be observed that the web unwinding and releasing lever I00 is capable of additional rocking movement to release a predetermined additional increment of the unwound web in the loop I06 so as to permit the Web to be advanced the full stroke of the grippers when the control mechanism indicates a deviation from a predetermined position of the web during the advancing movement.

Referring now particularly to Fig. 7, the detector unit 46 is arranged to energize the solenoid M2 to efiect release of an additional increment 9 of th'e'web when the unit is actuated bya registration mark 44, :and, as herein shown, the de tector unit may comprise any usual or preferred photosensitive control system adapted to con centrate a beam of light on the web and arranged to be excited by a rapid change in the reflective characteristics of the surface upon which the beam is concentrated, such as a rapid change from a light to a dark surface of the moving web, the dark surface being herein illustrated as comprising the spaced registration marks it arranged to intercept the beam. When the de tector unit is thus excited it is arranged to opcrate a relay I 76 to close a circuit H8 to the solenoid I 42. In practice, the light beam continues to play upon the web but the unit is operative to actuate the relay i'ld upon interception of the beam only during a predetermined time in the advancing cycle of operation, herein defined .as the scanning period and corresponch ing to a time when the web has been advanced substantially half way in its movement from one position of operation to another.

.As shown inFig. 7, the scanning period is controlled by the timing switch it which includes a stationary contact hit and a movable contact E82, the movable contact I82 being normally urged into circuit closing engagement with the stationary contact 483 by 'aleaf spring 1%. The

contact members the, it: are mounted upon an adjustable bracket 435, and, the switch is operated to open and close :a circuit I88 to the deteeter unit 46in timed relation to the operation of the machine by a cam I98 fast on a vertical cam shaft #92 and a cooperating cam roller liltcarried by an arm I96 pivotally mounted at The arm I95 is provided with a lateral extension arranged to engage and rock the contact arm I82 to open the circuit I83, and a spring 292 :is provided to urge the roller Ill l against its cam. The -switch cam shaft 192 is arranged to be rotated from the vertical shaft 88 by .agear train including a gear 2E4, idler gear 2% and gear 2% fast on the switch cam shaft 92.

Thus, the circuit M8 to the detector unit is closed by the cam 19!! to provide a scanning period during the advancing stroke, at whichtinie the detector unit is rendered operative to energize the solenoid M2 when the light beam; is intercepted by a registration mark. id. The time at which the scanning period starts relative to the moving period of the web may be varied by rotary adiustment of the contact carrying bracket E86 which latter is mounted "for rotary movement on the switch cam shaft Hi2 and is provided with an arcuate slotted portion 21% at its outer end arranged to receive a belt 252 for fastening the bracket in its adjusted position.

It "will be understood that the characteristics of the preferred detector unit iii are such that if the light beam is directly in alignment witha registration marl; M when the timing switch it is closed, thus indicating substantially uniform registration of the printed bag sections with the bag forming severing mechanisms, the relay "lit will not be actuated and also if the light beam is first directed on the mark and then passes from the marl; :to the relatively lighter surface of the web during the scanning period, also indicating substantially uniform and commercially acceptable registration of the bag sections, the relay will not be actuated toefiect additional releaseof the web. The only time the detecting unit will respond to the passage of the moving web is when the light beam is first directed onto the relatively light. surface of the web material when the timing switch is closed; and is then rapidly intercepted by the passage of a registration mark during the scanning period, such position being indicated generally in.

1 24-2 whichis in turn energized to rock the latch member till out of locking engagement with the end of the lever l Bil thus permitting the latter to be rocked upwardly to release an additional in-. crement of web material which additional in crement-iszadvanced by the grippers to provide an ovcrfeedor corrective stroke. Thereafter, in the operation roflthe machine, theuppermost bag section is sealed and provided with a charge of the commodity, the lowermost bag sectionis severed from theweb, and the unwindingand releasing mechanism is operated to effect normal un winding and releasing of the web during the succeeding cycle unless the position of the web during such cycle is such as to again require that an additional increment of the web be released and advanced. It will thus be seen that the releasing mechanism is rendered operative to permit the web to be advancedthe full stroke of the grippers to correct the position of the web during the same cycleof operation that a deviationiroma substantially uniform position of advancement is detected so as to assure that none of the bag sections deviate from such position beyond predetermined commercially acceptable limits.

From the description thus far it will be seen that in the operation of the web unwinding, releasing and advancing mechanisms successive normal or uncorrected web advancing movements which are slightly less than the predetermined spacing of the printed sections or the web will cause the marks to rise relative to the light beam concentrated on the moving web and that this action will be cumulative so that eventually the mark will intercept the light beam, as described, to effect additional release and advanceanism Ziltil; 'detectingunit Mill; solenoid operated latch tilt; andtlining switch dtli .so that in operation, although theweb advancing'mechanisrns are simultaneously operated through the same cam lit, yet each web may be individually controlled to selectively effect an additional advance of a web "as determined "by its individual detecting unit. In some cases no correction is'required depending 'on variations of the many conditions aiiecting the -26 expansion and contraction of the paper Web.

Thus the "bag forming webs aremaintain'ed in registered relation within predetermined tolerances with respect to the bag forming mechanisms comprising the package sealing mecha-- nism 22,1filling mechanism 30 and severing mech- 32 which may comprise the mechanisms illustrated and described in the Patterson .PatentNo. 2385,229 above referred to, and to which reference may be had for a more complete .des

ll scription and mode of operation thereof. As herein shown, successive connected filled and sealed bags advanced into operative position to the severing mechanism 32 are cut off and received in suitable guides 3%, 392 through which they are advanced in an upright position by intermittently operated pusher arms 3%, 396 to be delivered from the machine.

From the above description it will be seen that provision is made in the present apparatus for controlling the intermittent advance of a printed web of bag forming material into operative position with relation to the forming and severing mechanisms to maintain the length of individual bag sections within predetermined tolerances, the control mechanism being adapted to correct the linear advance of the web during the same cycle in which a deviation beyond such tolerances is detected.

While the preferred embodiment of the invention has been herein illustrated and described, it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is:

1. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising means operative independently of the advancing movement for withdrawing a length of web from a supply roll and for thereafter releasing a predetermined fixed length of said withdrawn portion slightly less in length than a predetermined. package length each cycle of operation, means for advancing the released length of web, control means including means for detecting the position of a registration mark at a predetermined time during the advance of the web, and means responsive to said detecting means when a deviation from a predetermined position beyond an allowable tolerance is detected by interception of the detecting means by the registration mark during said predetermined time for controlling said withdrawing and releasing means to effect release of a predetermined additional fixed increment of web material to be concurrently advanced by said advancing means during the same cycle of operation in which such interception occurs whereby to provide a net advance or the web a distance slightly more than the predetermined package length.

2. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising means operative independently of the advancing movement for withdrawing a length of web from a supply roll and for thereafter releasing a fixed predetermined length of said withdrawn portion slightly less in length than a predetermined package length each cycle of operation, a pair of horizontally and vertically reciprocable grippers arranged to advance the released length of web, control means including means for detecting the position of a registration mark at a predetermined time during the advance of the web, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is by interception of the detecting means by the registration mark during said predetermined time de-- tected for controlling said withdrawing and re'-- leasing means to effect release of a predetermined additional fixed increment of web material to be concurrently advanced by said grippers during the same cycle of operation in which such interception occurs whereby to provide a net advance of the web a distance slightly more than the predetermined package length.

3. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising means operative independently of the advancing movement for withdrawing a length of web from a supply roll and for thereafter releasing a predetermined fixed length of said withdrawn portion slightly less in length than a predetermined package length each cycle of operation, a pair of horizontally and vertically reciprocable grippers arranged to advance the released length of web, control means including means for detecting the position of a registration mark at a predetermined time during the advance of the web, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected by interception of the detecting means by the registration mark during said predetermined leasing means to effect release of a predetermined additional fixed increment of web material to be concurrently advanced by said grippers during the same cycle of operation in which such interception occurs whereby to provide a net advance of the web a distance slightly more than the predetermined package length, and means for operating said grippers through a predetermined linear advancing movement substantially equal to the longer length of web advanced, said grippers being yieldingly engageable with the web and capable of slipping relative thereto when the shorter length of web is fully advanced.

l. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising a sup ply roll, a reciprocable member arranged to engage the web and to eiiect withdrawal of a length thereof from the supply roll when moved in one direction and to release a predetermined length or the withdrawn portion when moved in the opposite direction, means for normally limiting the releasing movement of said reciprocable member to permit release of a length of web slightly less in length than a predetermined package length each cycle of operation, means for advancing the released length of web, control means including means for detecting the position of a registration mark at a predetermined time during the advance of the web, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected for removing said limiting means so as to permit release of an additional increment of web to be advanced by said advancing means during the same cycle of operation in which such deviation is detected whereby to provide a net advance of the web a distance slightly more than said package length.

5. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising a supi3 ply roll, a roclringly mounted member engageable with the web arranged to effect withdrawal of "a thereof irornthe supply roll when rocked in one direction and to release a predetermined length oi withdrawn portion when rocked in the or so 3 direction, means for normally limiting the movement of said reciting member topern -t relcase ol a fixed lenethof web slightly 1 in length than a predetermined packth each cycle of operation, means for sing; the released length of web, clamping means cooperating with said web to p cvent further wit l' the supply roll during the advancing movement, horizontally reciprocable members arranaedto and clamp toe free end or the web to prevent retraction of the web during the withdrawing operation, control means including means for detecting the position of a registration marl: at a predetermined time "duringthe advanceloi the web, and meansrresponsive to said detecting means when a deviation from predetermined position beyond allowable tolerances is detected by interception of the detecting means by the registration during said predetermined time i or removingsaid limiting means so as to permit release of an additional iixed increment of web to be advanced by said advancins means during the same cycleoi? operation in which such interception occurs whereby to pro-- v is a not advance oftheweb a distance slightly more than saidpachagele;

6. In a machine of the oil -cter described, in

L web feeding means for intermitvancing a web having equally spaced registration marks thereon l. fining successive paokagesections comprising roe-ans operative independently oi the advancing movement for withdrawing length or web and for thereafter releasing a tired predetermined length or" said withdrawn portion slightly less in length than a predetermined package length each cycle of operation, means for advancing the length web released, control means including a normally inoperative photo-sensitive detector arranged to cooperate with said registration marks, a timing switch for rendering said detector operative to detect the position of a registration mark at a predetermined time during the advance of the web, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected by inte'ception or the detecting means by the registration marl: during said predetermined time for controlling" said withdrawing and releasing means to enact release of a predetermined tional fixed increment of web material to be concurrently advanced by said advancing means during the same cycle of operation in hich such interception occurs whereby to provide a not advance of the web a slightlymore than said package length.

7. In a machine of the characterdescribed, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising a supply roll, a roclringly mounted member cng'ag'eable withthe web arranged to effect withdrawal of a length thereof from the supply roll when rocked in one direction and to release a predetermined. length of said withdrawn portion when rocked in the'opposite direction, a solenoid operated latch engageable with the rocked member for limiting the releasing movement to normally permit release of a length of Web =-slightly less in length than apre'determineel package length each cycle of operation, means for advancing the released length or web, and control meansincluding .a normally inoperative photo-sensitive detector arranged to cooperate with said registration marks, a timing switch for rendering-said detector operative to detect the position of a registration mark at a predetermined time during the advance of the web, said solenoid operated latch being responsive to said detecting means when a device tion from a predetermined position beyond allowable tolerances is detected to effect movement of the latch out of latching engagement with-said rocker member so as to gpermitrclease of a loredetermined additional increment of web material to be concurrently advanced by said advancing means during the same cycle of operation in whichsuch deviation is detected whereby to provide a net advanceof the web a distance slightly more than said package length.

8. In a machine of thecharacter described, in combination, web feeding means for intermittently advancing web having substantially equally spaced registration marks thereon define ing successivepackage sections comprising a supply roll, a roclrinely mounted member enaaaeaole with the web arranged to effect withdrawal of a length thereof from the supply roll when rocked one direction and to release a predetermined length of said withdrawn portion when rocked in the opposite direction, a solenoid operated latch eneaaeable with the rocked member for limiting the releasing movement to normally permit releaseoi a length oiweb slightly less in length than a predetermined-package lenatheach cycle of operation, means for advancing the release length of web, andcontrcl means including a normally inoperative photo-sensitive detector arranged to cooperate with registration mar e, a timing switch for rendering said detector operative to detect the posi ion of a registration mark at a predetermined time during the advance of the web, saidsolenoid operated latch being responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected to effect movement of the latch out or latching engagement with rocker member so to permit release of a predetermined additional increment of web material to be concurrently advanced by said advancing means during the same cycle of operation-in which such deviation is detected whereby to provide a net advance of the web a distance slightly more thansaid paciiage length, web advancing means compri l a pair of horizontally and vertically rcciprocable grippers having a predetermined linear advancing movement sub stantiaily equal to the longer length of web advar ced and being yieldin iy engcable with th wee capable of relative thereto when the shorter length of web is fully advanced.

9. Ina machine of the character described, in combination, web ieedin for intermitsubstantially ecual- 1 aesa'rss tive web at a predetermined time during the advance of the webs, and means responsive to said detectingmeans when a deviation from a predetermined position beyond allowable tolerances is detected by interception of the detecting means by the registration mark during said predetermined time for selectively controlling said withdrawing and releasing means to eliect effecting release of a predetermined additional fixed increment of web material to be advanced by said advancing means during the same cycle of operation in which such interception occurs whereby to provide a net advance of such web a distance slightly more than said package length.

10. In a machine of the character described, in combination, web feeding means for intermittently advancing webs having substantially equally spaced registration marks thereon defining successive package sections comprising supply rolls, reciprocable members arranged to engage the webs and to effect simultaneous withdrawal of a length thereof from each supply roll when moved in one direction and to release a predetermined length of the withdrawn portion oi each web when moved in the opposite direction, means for normally limiting the releasing movement or said reciprocable members to permit release of a length of web slightly less in length than a predetermined package length each cycle of operation, means for simultaneously advancing the released lengths of each web, control means in-. cluding means for detecting the position or" a registration mark on its respective web at a predetermined time during the advance of the webs, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected for selectively removing said limiting means so as to permit release of a predetermined additional increment of web to be advanced by said advancing means during the same cycle of operation in which such deviation is detected whereby to pro vide a net advance of such web a distance slightly more than said package length.

11. In a machine of the character described having web sealing means and web severing means, the improvement comprising web feeding means for intermittently advancing a web hav ing substantially equally spaced registration marks thereon defining successive package sections, said web feeding means comprising means operative independently of the advancing movement for withdrawing a length of web and for thereafter releasing a predetermined fixed length of said withdrawn portion slightly less in length than a predetermined package length each cycle of operation, means for advancing the released length of web, control means including means for detecting the position of a registration mark at a predetermined time during the advance or the web, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected by interception of the detecting means by the registration mark during said predetermined time for controlling said withdrawing and releasing means to efiect release of a predetermined additional fixed increment of web material to be advanced by said advancing means during the same cycle of operation in which such interception occurs to provide a not advance oi the web a distance slightly more than said package length.

12. In a machine of the character described having web sealing means and Web severing means, the improvement comprising web feeding means for intermittently advancing webs having substantially equally spaced registration marks thereon defining successive package sections, said web feeding means comprising supply rolls, reciprocable members operative independently of the advancing movement arranged to engage the webs to efiect simultaneous withdrawal of a length thereof from each supply roll when moved in one direction and to release a predetermined length of the withdrawn portion of each web when moved in the opposite direction, means for normally limiting the releasing movement of said reciprccable members to permit release of a fixed length of web slightly less in length than a predetermined package length each cycle of operation, means for simultaneously advancing the released lengths of each web, control means including means for detecting the position of a. registration mark on its respective web at a predetermined time during the advance of the webs, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected by interception of the detecting means by the registration mark during said predetermined time for selectively removing said limiting means so as to permit release of a predetermined additional fixed increment of web to be advanced by said advancing means during the same cycle of operation in which such interception occurs to provide a net advance of such web a distance slightly more than said package length.

13. In a machine of the character described, in combination, Web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising means operative independently of the advancing movement for withdrawing a length of web from a supply roll and for thereafter releasing a predetermined fixed length of said withdrawn portion slightly less in length than a predetermined package length each cycle of operation, a pair of horizontally and vertically reciprocable grippers arranged to advance the released length of web, control means including means for detecting the position of a registration mark at a predetermined time during the advance of the web, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected by interception of the detecting means by the registration mark during said predetermined time for controlling said withdrawing and releasing means to eiiect release of a predetermined additional fixed increment of Web material to be concurrently advanced by said grippers during the same cycle of operation in which such interception occurs whereby to provide a net advance of the web a distance slightly more than the predetermined package length, and cam operated means for effecting vertical reciprocation of said grippers a distance substantially equal to the longer length of web to be advanced, and means for initially adjusting the linear stroke of said cam operated means.

14. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising means operative independently of the advancing movement for withdrawing a length of web from a supply roll and for thereafter releasing a predetermined fixed length of said withdrawn portion slightly less in length than a predetermined package length each cycle of operation, means for advancing the released length of web, control means for detecting the position of a registration mark at a time when the web arrives at a point approximately halfway in its intermittent movement, and means responsive to said detecting means when a deviation from a predetermined position beyond allowable tolerances is detected by interception of the detecting means by the registration mark during said predetermined time for controlling said withdrawing and releasing means to effect release of a predetermined additional fixed increment of web material to be advanced by said advancing means during the stme cycle of operation in which such interceptlon occurs detected whereby to provide a net advance of the web a distance slightly more than said package length.

15. The method of feeding a web of package forming material having substantially equally spaced registration marks thereon defining successive package sections which comprises first withdrawing a length of package forming material from a supply thereof, then releasing a predetermined fixed length of the withdrawn portion slightly less in length than a predetermined package length, advancing the released length of web, detecting the position of a registration mark at a predetermined time during the advancing movement, and when a deviation from a predetermined position beyond allowable tolerances of the registration mark is detected releasing and advancing a predetermined additional fixed increment to obtain a net advance a distance slightly more than said package length.

16. The method of feeding webs of package forming material having substantially equally spaced registration marks thereon defining successive package sections which comprises first withdrawing a length of package forming material for each web, then simultaneously releasing a predetermined fixed length of each withdrawn portion slightly less in length than a predetermined package length, advancing the released lengths of web, detecting the position. of a registration mark on the individual webs: at a predetermined time during the advance of the Webs, and, when a deviation from a predetermined posi tion beyond allowable tolerances of a registration mark of one of the webs is detected, selectively releasing and advancing such web a predetermined additional fixed increment to obtain a not advance of such web a distance slightly more than said package length.

STANLEY R. HOWARD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,474,748 White Nov. 20, 1923 1,873,057 Smith Aug. 23, 1932 2,035,201 Smith et a1 Mar. 24, 1936 2,199,708 Maxfield May 7, 1940 2,269,542 Howard Jan. 13, 1942 2,338,596 Pitt et a1. Jan. 4, 1944 2,385,229 Patterson Sept. 18, 1945 2,437,560 Sandberg Mar. 9, 1948