US2636731A - Web feeding means for container forming apparatus - Google Patents

Description

April 28, 1953 s. R. HOWARD 2,636,731

WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Filed March 50, 1948 4 Sheets-Sheet l 60 INVENTUR.

.Sian/ely ,e /awara ATTORNEY April 28, 1953 s. R. HowARD 2,636,731

WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Filed March 30, 1948 4 Sheets-Sheet 2 /1 40 4 2 58 IN VEN TOR.

April 28, 1953 s. R. HOWARD 2,636,731

WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Filed March 30, 1948 4 Sheets-Sheet 3 ATTORNEY April 28, 1953 s. R. HOWARD 2,636,731

WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Filed March 50, 1948 4 Sheets-Sheet 4 INVENTOR. 272g. 7 Jamy l? /awdrd BY (j. 54:47 CLwclwbl ATTORNEY Patented pr. 28, 1953 WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Stanley R. Howard, Milton, Mass., assignor to Pneumatic Scale Corporation, Limited, Quincy, Mass., a corporation of Massachusetts Application March 30, 1948, Serial No. 17,972

14 Claims. 1

` This invention relates to container forming apparatus.

In general the object of the invention is to provide a novel and improved packaging machine wherein a printed web of iiexible sheet mater-iai, such as heat scalable printed paper, is utilized to` produce successive lled and sealed containers in a rapid, efficient and commercially acceptable manner and wherein novel provision is made for controlling the feeding of the web to effect registration 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 em bodied in a tea-bagging machine.

With this general object in view and suc others as may hereinafter appear, the invention consists in the packaging apparatus and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this speciiication.

in the drawings illustrating the preferred embodiment of the invention, Fig. 1 is 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. 4 is an enlarged detail view in side elevation of web retracting mechanism and control means therefor; Fig. 5 is a detail view in cross section taken on the line 5-5 of Fig. l;

Fig. 6 is a front elevation of a completed tea bag and adjacent sections indicating the length of the normal net advance, and the advance with a corrective stroke, relative to the predetermined length of a bag section or distance between the printed indicia on the web; and Fig. 7 is an electrical wiring diagram for the control mechanism.

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 of container forming material 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 States patent to Patterson No. 2,385,229, issued September 18, 1945. As herein shown, such machines may be constructed in duplex form for simultaneously producing two strips of connected and lled bags and for severing the strips through sealed portions thereof to form individual packages.

In the operation of such a machine, and as illustrated in Fig. l, a web of heat-scalable paper It is withdrawn from a supply roll I2 thereof and advanced over container forming mechanism I6 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 I8. The `container forming material is drawn over the forming mechanism I6 by vertically and horizontally reciprocable gripping and advancing mechanism 20 operative to nominally advance the strip substantially one bag length each cycle of operation and to present the strip `in operative relation to the sealing mechanism, indicated generallyat 22, arranged to apply heat and pressure to seal the strip simultaneously along a transverse Zone `24 and an adjacent longitudinal zone 26 during each sealing operation to forma series of connected bag sections closed on one side `by the folded edge 2t and heat sealed along the remaining side and at the top and bottom.

The paper being unwound from the supply roll l2 and advanced by the gripper mechanism 20 is arranged to pass over a take-up roll 5l! mounted for axial movement in a bracket S5. and then over an idler roll 1I. The movable take-up roll 59 is yieldingly urged outwardly in its supporting bracket by springs t1 and is capable of inward movement during the unwinding operation` in order to maintain the web relatively taut and to take up any slack between the gripper mechanism and the supply roll. The supply roll l2 may be provided with suitable retarding means such as a friction bearing, indicated at 5 l for preventing inadvertent unwinding of the web material, and, the idler roll 'Il may likewise be maintained under a slight friction.

Provision is also made for depositing successive charges of the commodity into successive of the uppermost bag sections, as they are being formed, by feed-ing mechanism indicated generally at 30, the feeding mechanism operating in timed relation to the operation of the strip advancing and heat sealing mechanisms 2U, 22 respectively. In the operation of the machine, the open top of a bag section which has been provided with a charge of the commodity during one cycle of operation is closed during a succeeding cycle. Thereupon, the strip is intermittently advanced to severing mechanism, indicated generally at 3.2, which operates to sever the strip through successive transverse sealed portions 2t to form individual iilled and sealed bags.

The machine illustrated and described in the Patterson Patent No. 2,385,229, above referred to, was particularly designed forproducing pa- 3 per tea bags made from a web of plain, unprinted heat scalable paper, and such machines are at the present time in extensive successful commercial use. However, when printed webs are used inv a machine having a linear web advancing mechanism arranged to advance the web a length corresponding to a predetermined length of a bag section it is diiiicult to maintain correct registration of successive printed bag sections with the package forming instrumentalities since, l

in practice, the sections may vary due to inaccuracies in printing, the eiect of variations in atmospheric conditions upon the web 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 printed sections were cumulativeso that eventually the web became out of register with the bag forming and severing mechanisms`.

In the `illustrated embodiment of the invention, see-Fig;Y 2, each web gripping and advancing mechanism 2d includes a pair of opposed cooperati-ng grippers lill, l2 mounted to be horizontally reciprocated into and out or gripping engagement with the web, and, to be vertically reciprocatedto advance the web each cycle of peration.` In practice, the linear stroke of the grippers is initially adjusted so as to advance the Webfa distance slightly more than the predetermade for retracting the web a distance sufficient so that the net advance of the web during each normal-cycle of operation is slightly less than the predetermined bag length.

In the illustrated embodiment of the inventien, provision is made for preventing retraction of the web 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 remain in its initially advanced and overied position when a deviation of the registration mark from a predetermined position beyond permissible tolerances occurs thereby providing in effect a corrective stroke in the linear advance of the web during the same cycle of operation in which detection of the need for correction by the control mechanism occurs.

In general, the control mechanism includes a photo-sensitive detector, indicated generally at 46, arranged to cooperate with the spaced registration marks M during the advancing cycle of operation; a timing switch le arranged to render theA detector operative at a predetermined time in the web advancing cycle; web retrac'ting means, indicated generally at t9; and a solenoid operated latch l) arranged to render the web retracting means inoperative when actuated by the detector mechanism to permit an overfeed of the web. The gripper members are arranged to yieldingly engage the web during the advancing stroke with sufficient firmness to elect positive unwinding and advancement of the web, and, immediately after completing the web advancing stroke the gripper pressure may bereleased sufficiently to permit slippage of the web between the grippers during the web retracting operation.

In practice, thev photo-sensitive detector fl 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 lll 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 prevent a retractive stroke 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 d, and then only when the beam is out off by the leading edge of a rapidly passing mark. If the mark does not appear during the scanning period, no correction is made, and, if the beam falls directly on the mark, and the mark then passes by so that the beam then falls on the relatively lighter background of the web during the scanning period no correction is made.

In the operation of the apparatus, assuming that the average bag length is approximately 21/2 inches, for example, successive normal advancing and retracting movements are arranged to cause a net advance of the web about sl-g of an inch less than the average bag length orv about Z- inches net advance each cycle so as to efiect a gradual and cumulative rising or creeping up" of the marks lili relative to the light beam until a point is reached where the beam is intercepted by a mark moving therepast. When this occurs the retracting mechanism is rendered inoperative so that the web is permitted to remain in its fully advanced position, the linear advance being slightly more, approximately g1g of an inch more, than the predetermined length of a bag section, making the total stroke about 2&-2- inches. lIhus, it will be seen that the web advancing movement is either increased or decreased relative to the predetermined bag length within such tolerances as to effect substantial registration of successive bag sections with the container forming mechanisms.

Referring now to Figs. 1 and 2 for a more detailed description of the web advancing and retracting mechanisms, as thereinshown, opposed grippers i, t2 are arranged to be horizontally reciprocated in brackets 52, 5t respectively, the latter being adjustably clamped upon vertical rods 55, 58 supported for vertical reciprocation in suitable bearings provided in the machine frame. The rods, 56, 58 are arranged to be vertically reciprocated in timed relation to the operation oi the bag forming mechanisms by a cam lill mounted fast on the main cam shaft |60, and, as herein shown, provision is made for initially adjusting the effective stroke or" the cam in order to enable adjustment of the linear advance of the grippers with relation to the spacing of the bag sections of the web. The rods 56, 58 are secured at their lower ends to a pair of yokeshaped tie pieces 62 only one. o which is shown, the illustrated tie piece having a central slotted portion 64 for cooperation with a slide block 66 mounted on one end of an eccentric stud 68 carried in a lever 'i fast on a rocker shaft 12,*the eccentric stud being rotatably adjustable in the lever 1B. The eccentric end of the stud '63 is provided with a roller I4 cooperating with the fixed cam path of the cam (ill, as clearly shown in Fig. 5,

With this `construction it will be` seen that by rotary adjustment of the eccentric stud 63 the effective length of the lever arm lil 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 the roller` 14 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 effective stroke. Thus, the linear movement of the gripper units may be initially adjusted so as to effect a linear advance of the web a distance slightly more than the predetermined spacing between successive markings 44. It will be understood that the gripper carrying brackets 52, 54 may be adjusted on their respective rods 56, 58, to align the cooperating gripper units 40, 42 for lcooperation with successive transverse sealed portions 24 of the web.

While the above description has been conned thus far to the opera-tion of one pair of cooperating gripper units 40, 42 `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 of gripper units 400, 420 are carried by the brackets 52, 54

respectively, as illustrated in Fig. 3, the brackets being also adjustably supported upon similar vertical rods 560, 580 arranged to be vertically reciprocated by the cam 60 through similar connections including a lever arm fast on the rocker shaft 12 so that in operation each pair of grippers are simultaneously operated to cause the webs to be advanced into operative relation to their respective container forming, lling and severing mechanisms.

As illustrated in Figs. 2 and 3, each gripper unit 40, 42 and their corresponding units 400, 420 are supported for horizontal reciprocation upon individual rods 16 slidingly carried in the brackets 52, 54, each rod being provided with a coil spring 18 interposed between a portion of its supporting bracket and a collar 80 adjustably secured to the rod, the springs being arranged to urge the grippers inwardly into cooperating engagement with their opposing grippers and the container forming webs. The rods 13 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 |30 secured to vertical cam shafts 88, 80 respectively, Thus, in the operation of the machine, the gripper units 4E?, 4530 and 42, 420 are horizontally reciprocated simultaneously into and from engagement with the webs, the springs 1B efiecting a yielding engagement therewith and the cams 8G operating to positively separate the grippers. In the present embodiment of the invention, the cams 8B may be designed to relieve the grip on the web as soon as the grippers have completed their downward stroke to permit the web to be drawn back by the retracting mechanism, as indicated at 81 in Fig. 3, rI'he vertical cam shafts B8, 90 are arranged to be rotated from the main cam shaft |60 by connections including bevel gears 92, 94 to the vertical shaft 88, bevel gears 96, 98 to a horizontal shaft |06, and a second set of bevel gears to the vertical shaft S0. One gripper member, 40, may be yieldingly mounted to provide a more accurate control of the gripper pressure, and, as herein shown, the gripper member 40 is provided with a pair of pins lilI, |03 slidingly carried in a block |36 secured to the endof the rod 16. r Springs |01 coiled about the pins and interposed between the gripper member and the block are arranged to yieldingly urge the gripper 40 toward its opposcollar I I6.

6 ing gripper, each pin I0 I, I 03 being providedwitl'i a nut |09 on its outer end for adjustably -limiting the movement in such direction.

As above stated, the retracting mechanism indicated generally at 49 is arranged to normally retract the web slightly in order to effect a normal net advance of the weby a distance slightly less than the predetermined bag length, and,` as shown in Figs. 1 and 4, the reftracting mechanism may comprise a pvotally mounted lever |02 arranged to cooperate with the idler roll 1| to grip the web between the end of the lever |02 and the idler roll and to effect reverse rotation of the roller 1| and retraction of the web when the lever is rocked in a clockwise direction viewing Fig. 4. As* herein shown, the lever ft2 may be mounted fast on a stud |04 piv- 4 otally carried by one arm |06 of a two-armed lever pivotally mounted on a rocker shaft |08, the second arm ||0 being provided with a, spring ||2 arranged to yieldingly urge the retracting lever into cooperating engagement with the r-oller 1|. The spring I I2 is connected at its other end to a similar arm forming a, part of the retracting mechanism for the second web of the duplex unit. A stop screw I I4 engageable with the outer end of the arm |06 is arranged to adjustably limit the position of the lever |02 with relation to the roller 1| for most efficient results during the retracting operation.

As illustrated in Fig. 1, `the lever |02 is arranged to be rocked to eiect retraction of the web by a cam ||8` fasten the horizontal cam shaft lili] and through connections including a f` cam roll |20 Icarried on the end of a vertical rod |22 mounted to be reciprocated in a bearing |24, the rod |22 being urged downwardly to hold the roller |20 against its cam by a spring |26 interposed between a portion of the bearing and a The upper end of the rod |22 is provided with a tie piece `|28 which carries two separate rods |25, |21 for cooperation with opposed retracting mechanisms of the duplex unit. Each rod |25, |21 is provided with a yieldable lconnection in which the rod is arranged to pass through a swivel |29 carried by an arm |3| also fast on the stud |34 the rod being provided with a collar |30 for engagement with the underside of the swivel to positively urge the retracting lever I 92 into an inoperative position. A coil spring |32 interposed between the other side of the swivel and a nut and washer |34 at the outer end of the rod permits the lever |02 to `be yieldingly rocked in a direction to eiect the retracting movement. A third arm |31 fast on the stud |04 is arranged to cooperate with a stop screw ||1 carried by the arm |06 for adjustably limiting the rocking or retracting movement oi the lever |02, the yieldable connection permitting the rod |25 to slide through its swivel |29 when the arm |31 engages'the stop. As previously described, the idler roll 1| may be held under a slight friction to prevent slippage.

From the description thus far it will be observed that the printed container forming web having spaced registration marks 44 thereon corresponding to the predetermined length. of successive package sections may be intermittently advanced a distance slightly more than the distance between registration marks, initial adjustment of the linear feed being accomplished by rotation of the eccentric roller Vstud 68 in the lever arm 10 to provide an overfeed of the web,

normally retracted a short distance each cycle of-operation.'scz'asitmobtainla net..advancezofrthe webta 4distance-fl slightly-f; 1ess:;than the.- predeteri.- mined package; length. :In practice; thefcam -|f|.8 may be;.designed,toretain.the, lever lutin its-tref tracting posit-ionv until; the.I beginningof.Y thew next cycle of operation, whereupon the lever H12-'may normally maintained in an; inoperative position bywa spring l||;,-',When theretracting member |62 is thus heldby thelatclfiv 59, -theloperating rod |25 ispermitted to slide through itsswivel 2.9 by virtueV of the yieldableconnection;

Referring now-particularly to Fig.l 7, the detec- `torunit tvisarranged-to.energise the solenoid |33 to'prevent retractionofthe webwhen the-dctector Lunit is actuatedby a registrationv mark lll and, as herein shown, thedetector unitmay comprise any usual -or preferred photo-sensitive controlsystemA adaptedv to,` concentrate abeam of light-onfthey web and which is arrangedL to be excited by a rapidrchange; in the reflectivecharacteristicsgof thesnrf-ace uponA which the beam.. is

concentratedrsuch.asawrapid-change from alight to a dark surface'vofthefmoving w.cb,\the dark surfacebeing hereinillustrated as comprising' the spacedregistrationf; marks 46|, arranged tointercept thelbeam.: Whenzthedetector unit is thus excited, it is. .arrangeiitooperate a relay |18 to close azcircuit` |38 to;the`s,olenoid-|3S. Inpractice, the lightxbeam is continuously operated; but the unitis operativetoV actuatertheirelay upon interceptionof.the-:beam` only during a predetermined timein the cycle; of a operation,` suchpredetermined time being herein defined .as thesscanning period; andpwhich;cOrreSpOndsto a time when the; web; has ,xbeenf advanced substantially halfway in its movementifrom one positionfof operation toanother.

As shown in Fig... 7 the `scanning period iscontrolled by; the. timing` switch` l8r :which includes a stationaryi contact |80 and amovable contact. |82; the: movable contact-|82 being normally urgedinto` circuit closing'engagement with the stationary contact |80 yby'y a leaf` springr |84. The contact members Ill,4 82eare mounted upon an adjustable bracket. I 86, and, the switch `isoperated to open` and close a circuit1|88 to the detector unit` 46.in.timed relationtdv the operation of themachineby a cam |9|l fasten a vertical cam shaft |.92-and, a cooperatingy cam roller |96 carriedbyfanarmi |96 pivotally. mounted atr |98. The arm.,|,96 is provided with alateral extension arranged to engage .Y and. rock ,ther conl tact arm.. 82,to open the circuit l| SS, .and aspring 202 is provided `,to `urge the, roller l 94. against yits cam. Theyswitchicam shaft |92 vis arrangedgtobe rotated from Athe -verticalshaft 8 8 by, a geartrain includinga gear 2,04, idler.y geartiilay and gearlll.

fasten: the switch. cam shaft.. 92.;

'I1-hum the rcircuit. I V88..- =-to/ the detector. is

period Adtiring-thefadvancingystroke; at-Jwhichttime t thadetectomunitzis rendered operative to .energisee 75'...

8. theysolenoidwhen the. light, beam is intercepted by a registration mark. The time jat which the scan,-

v ning periodstarts relative tothe movingtperiodof the web. may bevariedby rotary adjustment of thezcontact .carrying bracket |86 mounted for rotaryl movement on the switch cam shaft |92 and providedwithan arcuate slotted portion 2 El at its outer end arrangedy to receive a bolt 2|2' for fastening the bracket in its adjusted position.

It will be understood that the characteristics of the preferred detector unit 46 are such that if the lighttbeam is-directly in alignment with a registratiorrmarkv 44 when the timing switch it is closed, thus indicating substantially registration of lthe package sections Withthe container forming mechanismsV Within permissible tolerances, the relay, |16 will notbeactuatedand also if the light beamtis directedk on the. mark and then passes fromI themark. to the relatively lighter surface ofthe Web material during the scanning period, valso indicating substantially uniform and commercially acceptable registration of the package sections, the relay will not be actuated to preventiretraction of the` web. The only time the detecting unit will respond to the passage of the moving web is whenthe. light beam is first directedonto the relatively light surface of the web material when the timingswitch is closed and is then rapidly intercepted by the passage of a relatively,v darker surface registration mark during the scanning period, such .positionbeing indicated generally in Fig. 7 wherein the switch contacts |80, |82 are closed and the light beam isjust about to be intercepted by a mark lill, indicating thatfthe package sections are lagging slightly behind proper registrationwith the container forming and severing instrumentalities.

Upon interception of the light beam by the registration mark at such time, the relay |16 will beactuated to close the circuit HS to the solenoid ISB-which is in turnenergised to rock the latch member 5|! into latching. engagement with the extended end of the arm |37 .thus locking the lever |02 in its inoperative position to prevent retracr tion-of the webfrom its initially advanced and overfed position. Thereafter, in the operation of the machine, the uppermost package section is sealed and providedwith a charge of the commodity, the lowermost package section is severed 1 from the web, andthe advancingvmechanism is operated to eiect normal advancement and retraction of the web during the succeeding cycle unless the position of the web during such cycle is such, as tovagain require that the initial over advancement of theweb be maintained. It will thusbe seen thatthe retracting mechanism is rendered inoperative to retract the web and that in effect, corrects the position of the web during thesame cycle of operation that a deviation is detected to maintain the yariations in the lengths of successive package sections within predetermined tolerances.

From. the description. thusfar` it will be seen that in theoperation of the web advancing and retracting mechanism, .the web is normally advanced .a'distance slightly less than the average spacing of successive printed package sections and thatlsuch predetermined advancement will cause the. registration marks to rise relative to thelight'beamconcentrated'on the moving web andrthat. this action will be cumulative so that eventually the marlcwill intercept the.` light beam, as described, to render the retracting mechanism inoperative andpermit the web to remain ,v in its initially. advanced position' of a distance slightly more than the predetermined package length. As herein shown, similar control mechanism is provided for controlling each web of a duplex container forming machine, and includes a similar retracting unit ddii, detecting unit 46d, solenoid operated latch teil. and timing switch 480 so that in operation, although the web advancing mechanisms are concurrently op erated through the same cam dii, yet each web may be individually controlled to selectively prevent retraction of the web as determined by its individual detecting unit.

Thus, the package forming webs are maintained in substantially registered relation within predetermined tolerances with respect to their respective package forming mechanisms comprising the package sealing mechanism 2.52, filiing mechanism 3B, and severing mechanism 32. These mechanisms may comprise the mechanisms illustrated and described in the Patterson Patent No. 2,385.229 above referred to, and to which reference maybe had for a more complete description and mode of operation thereof. .As herein shown, successive connected lled and sealed packages advanced into operative position to the severing mechanism 32 are cut off and received in suitable guides 390. 392 through which they are advanced bv intermittently operated pusher arms 394, 396 to be delivered from the machine.

From the above description it will be seen that provision is noade in the present apparatus for controlling the intermittent advance of a printed web of container forming material into operative position to the package forming and severing mechanisms in accordance with substantially equally spaced printed indicia on the web defining the length of individual package sections. the control means being adapted to correct the linear advance of the web during` the same cycle in which a deviation from a predetermined spacing is detected, whereby to maintain theispacing corresponding substantially to successive printed package sections and within commercial limits of deviation therefrom.

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: u

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 denning successive package sections comprising means for advancing the web ayed distance slightly more than a predetermined package length, means for retracting the web a slight fixed distance to provide a net advance of the web a distance slightly less than said predetermined package length each cycle of operation, control means including means for detecting the position of a registration mark while the web is rfoving and being advanced and at a predetermined time during the advance of the web, and means responsive to said detecting means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said predetermined time for rendering said retractingi means inoperative during the same i cycle of operation in which such interception ocinitially advanced and slightly overfed position.

2. In a 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 pair of horizontally and vertically reciprccable grippers arranged to advance the web a xed distance slightly more than a predetermined package length, means for normally retracting the web a slight fixed distance to provide a net advance of the web a distance slightly less than said package length each cycle of operation, control means including means for detecting the position of a registration mark while the web is moving and being advanced and at a predetermined time during the advance `of the web, and means responsive to said control means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said predetermined time for rendering said retracting means inoperative during the same cycle of operation in which such interception occurs whereby to permit the web to remain in its initially advanced and slightly overfed position.

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 denning successive package sections comprising a supply roll, web guiding means including an idler roll, a pair of horizontally and vertically reciprocable grippers for withdrawing the web from the supply roll and over said idler roll to ad- Vance the web a xed distance slightly more than a predetermined package length, means cooperating with said idler roll for normally retracting the web a slight xed distance to obtain a net advance of the web a distance slightlyless than said package length each cycle of operation, control means including means for detecting the position of a registration mark while the web is moving and being advanced and at a predetermined time during the advance of the web, and means responsive to said detecting means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said predetermined time for rendering `said retracting means inoperative during the same cycle of operation in which such interception occurs whereby to permit the web to remain in its initially advanced and slightly overfed position.

4. in a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon deiining successive package sections comprising means for advancing the web a xed distance slightly more than a predetermined package length, means for normally retracting the `web a slight nxed distance to obtain a net advance of the web a distance slightly less than said i package length each cycle of operation, control means including a normally inoperative photosensitive detector arranged to cooperate with said registration. marks, a timing switch for rendering said detector operative to detect the position or a registration mark while the web is moving and being advanced and at a predetermined time during the advance of the web, and means responsive to said detecting means when the length being advancedis detected as being withinV an allowable tolerance by the interception oi said detecting .meansby said registration mark during said predetermined time for rendering retracting means inoperative' during the same cycle of operation vvin which such interception occurs whereby to permit the web to remain in its initially advanced and slightly overfed position.

5. In a .machine .of the character described, .in combination, web feedingmeans for intermittently advancing a web having substantially equally vspaced vregistration marks ther-coni defining successive package sections, comprising a .pair of horizontally .and vertically reciprocable grippers arranged tol-advance the web a fixed vdistance slightlyl more than a predetermined package length, .means fornormally:retracting 'the web a slight 'nxed distance to obtain a net advance of thefweb a distance .slightly than said package length Y, each 'cyclel of operation, control means including elcctro-responsive-means -for detecting the position ci a registration mark vvhiley the 1web-xis.:movingi and-'being advanced 'and at a predetermined time during the advance of the web, and a solenoid operated member .responsive to said ycontrol means `arranged` to prevent 'operation of- Asaid Iretracting means when thelengthfbeing. advanced is detected as 4being within an'allowable toleranceby the interception or" said :detectingl means yby said registration "mark during-'said predetermined time for preventing vretraction xoifthe web during the same cycle :oi `operationrin'"which such interception occurs whereby to permit. thewebto remain in fits'l initially 'advanced and' slightly overfed position.

6: .in a 'machine of 'the/character described, .in combination; web feeding'means for intermittentlyl advancing a web having substantially equally spaced registration 'marks thereon deiiningsuc'cessive packagesectiona vcon'iprising a supply roll, web guidingmeans including an'idler `rollya pair of -hori-zontally 4and vertically reciprocable grippers for withdrawing the web from lthesupplyrolland advancing the web vover said idler roll a :ixed distanceslightly` .more than a 'predetermined 'package.length,A `web -retracting .means vcomprising aA pivotalbar Aa'nr-angedfto 'cooperate with said vidleriroll for normally retracting .the vweb afrslightiix'ed distance to 'ob- `tain a n et advance of' the lweb `a distance'slightly less than said package lengthfe'ach cycle oiioperation, control me'ansin'cluding a normally finoperative photo-sensitive detector arranged to cooperate with said registration a 'timing switch for renderingsaid detector operative to detect the 'position Aof a *registrationinark while the web is moving and being vadvanced and at a predetermined time duringtbe zuivance oi 'the web, and a solenoid operated member responsive to `said control means arranged 4to engage said 'pivotal bar when the length being advanced is detected 'as being within an allowable tolerance by I the interception of sa'iddete'cting means by said registration mark during said predetermined time to prevent retraction of `the web duringth'e same cycle of operation in Awhich such interception occurs whereby .to'permit th'e'web to remain in its initially 'advanced V'and 'slightly overfed po- 'sition.

'7. In a machine of the character described, in combination, web feeding means for intermittently advancing a web 'having substantially 12 equally spaced -registration marks thereon derining successive package sections, comprising a pair of horizontally and vertically reciprocable grippers, cam operated means for effecting vertical reciprocation of said grippers, means for initially adjusting the linear stroke of said cam operated means to advance the web a fixed distance slightly' more than a predetermined package length, means for normally retracting the web a slight fixed distance to provide a net advance of the web a distance slightly less than said package length eachlcycle of operation, control means including means for detecting the position of a registration mark while the web is moving and being advanced and at a predetermined time during the advance of the web, and means responsive to said control means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by lsaid registration mark during said predetermined time for rendering said retracting means inoperative during the same cycle of operation 1in which such interception occurs wherebyto permit ther web to remain in its initially advanced land slightly overfed position.

8. In a machine of the character described, in combination, web feeding means for intermittently advancing .a web having substantially equally spaced registration marks thereon deiining successive package sections, comprising a pair of horizontally `and vertically reciprocable grippers, arranged to advance the web a iiXed distance slightly more than a predetermined package length, cam operated means for effecting horizontal reciprocation of said grippers into and out of gripping engagement with the web, means for normally retracting the web a slight iixed distance to provide a net advance of the web a distan-ce slightly less than said package length'e'ach cycle Vof operation, control means including means for detecting the position of a registration mark while the web is moving and being advanced and at a predetermined time during the advance of the web, and means responsive to said control means when vthe length being advanced is detected as being within an allowable tolerance by the interceptionof said'detecting means by saidregistration mark during said predetermined time for rendering said retracting means inoperative duringthe same cycle of1oper'ationfin`vvhi-ch `such interception occurs whereby to permit the web to remain 'in its" initially"advanced and slightly overfed position.

9. 'In a. duplex :machineiof the character described,l`in"combination, lweb :feeding means for intermittently Aadvancing `two webs each having substantially equally spaced-:registration marks thereon deiining successivepackage sections comprising means for simultaneously advancing the webs a xed distance slightly more than a predetermined package length, means for normally retracting each web. atslight 'distance to provide a net advance'of 'the Web aixed distance slightly less than' said.' package length'each cycle of operation, lco'ntrolnieans for 'each web .including means for detecting .the position of a `registration mark on' its respectiveweb while the web is moving and being advanced :and iat a Apredetermined time during "the "advance ci ,the web, and means responsive to' "said 'detecting means -when the length being vadvanced is'detected as being within an allowable tolerance Aby the interception of `said 'detecting .meansby saidregistration mark during "said 'predetermined `time .for :selectively:

rendering the respective retracting means inoperative during the same cycle of operation in which such interception occurs whereby to permit such web to remain in its initially advanced and slightly overfed position.

10. In a machine of the character described, in combination web feeding means for intermittently feeding two Webs each having substantially equally spaced registration marks thereon, denning successive package sections, comprising supply rolls, web guiding means including idler rolls, means for withdrawing a web from each supply roll and over their respective idler rolls simultaneously to advance each web a xed distance slightly more than apredetermined package length, means cooperating with each idler roll for normally retracting the webs simultaneously a slight xed distance to obtain a net advance of the webs a distance slightly less than said package length each cycle of operation, control means for each web including means for detecting the position of a registration mark on its respective web while the web is moving and being advanced and at a predetermined time during the advance of the webs, and means responsive to said -control means arranged to cooperate with its respective retracting means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said predetermined time for selectively preventing retraction of a web during the same cycle of operation in which such interception occurs whereby to permit such web to remain in its initially advanced and slightly overfed position.

11. In a machine of the character described, in combination, web feeding means for intermittently feeding two Webs each having substantially equally spaced registration marks thereon, defining successive package sections, comprising supply rolls, web guiding means including idler rolls, a pair of horizontally and vertically reciprocable grippers for each web, means for operating said grippers simultaneously for withdrawing the webs from the supply rolls and advancing them over their respective idler rolls to advance each web a xed distance slightly more than a predetermined package length, means cooperating with each idler roll for normally retracting the webs a slight fixed distance to obtain a net advance of the webs a distance slightly less than said package length each cycle of operation, control means for each web including a normally inoperative photosensitive detector arranged to cooperate with the registration marks on its respective Web, timing' switches for rendering their respective detectors operative to detect the position of a registration mark while the web is moving and being advanced and at a predetermined time during the advance of the webs, and means responsive to said detecting means arranged to cooperate with its respective retracting means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said predetermined time for selectively preventing retraction of a web during the same cycle of operation in which such interception occurs whereby to permit such web to remain in its initially advanced and slightly overfed position.

12. In a machine of the character described, adapted for operation upon a web' having sub- Lit) stantially equally spaced registration marks thereon defining successive package sections, web sealing means and web severing means, the improvement comprising web feeding means for intermittently advancing a web, said web feeding means being adapted to advance the web a xed distance slightly more than a predetermined package length, means for normally retracting the web a slight distance to provide a net advance of the web a Xed distance slightly less than said package length each cycle of operation, control means including means for detecting the position of a registration mark while the web is moving and being advanced and at a predetermined time during the advance of the web, and means responsive to said detecting means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said predetermined time for rendering said retracting means inoperative during the same cycle of operation in which such interception occurs whereby to permit the web to remain in its initially advanced and slightly overfed position.

13. In a machine of the character described having means for forming lling and sealing webs of container forming material to form packages including web sealing means and web severing means, the improvement comprising web feeding means for intermittently advancing two webs each having substantially equally spaced registration marks thereon, defining successive package sections, said web :feeding means comprising means for simultaneously advancing the Webs a fixed distance slightly more than a predetermined package length, means for normally retracting each web a slight distance to provide a net advance of the webs a. fixed distance slightly less than said package length each cycle of operation, control means for each web including means for detecting the position of a registration mark on its respective web while the web is moving and being advanced and at a predetermined time during the advance of the webs, and means responsive to said detecting means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said predetermined time for selectively rendering the respective retracting means inoperative during the same cycle of operation in which such interception occurs to maintain the web in its initially advanced position.

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 dening successive package sections comprising means for advancing the web a fixed distance slightly more than a predetermined package length, means for normally retracting the web a slight xed distance to provide a net advance of the web a distance slightly less than said package length each cycle of operation, control means including electro-responsive means for detecting the position of a registration mark While the web is moving and being advanced and when the web is advanced approximately half way in its intermittent movement, and means responsive to said control means when the length being advanced is detected as being within an allowable tolerance by the interception of said detecting means by said registration mark during said 15 predetermnedtime for rendering said retractng .means inoperative durngthe same cycle of operation in which such interception occurs whereby to permit the Web to remain in its initalf; advanced and slightly overfed position.

STANLEY R. HOWARD.

References Cited inthe le of this patent UNITED STATES PATENTS Number Number 16 Name Date Grover Nov. 16, 1926 Grover Feb. 15, 1927 Ferenc May 24, 19,32 Morse Dec. 19, 1933 Broekhuysen Jan. 30, 1940 Maxfield May 17, 1940 Patterson Sept. 18, 1945

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