US2451287A - Wrapper feed for wrapping machines - Google Patents

Description

Get. 12, 1948. 'w. HOPPE WRAPPER FEED FOR WRAPPING MACHINES 4 Sheets-Sheet 1 Filed April 8, 1944 INVENTOR ML/AMfiZPPE BY' I 44 m ATTORNEYS Oct. 12, 1948. w. HOPPE WRAPPER FEED FOR WRAPPING MACHINES 4 Sheets-Sheet 2 Filed April 8, 1944 I INVENTOR M 4 MM flZPPE BY %L;-*%Z TTORNEYS CE. 12, 1948. w, HQPPE WRAPPER FEED FOR WRAPPING MACHINES 4 Sheets-Sheet 3 Filed April 8, 1944 Z M /m m +N W W W QH A a Oct. 12, 1948. w. HOPPE WRAPPER FEED FOR WRAPPING MACHINES 4 Sheets-Sheet 4 Filed April 8, 1944 INVENTOR Mil/1417156172 TTORNEYS Patented Oct. 1 2, 1948 U NITED STATES "PATENT OFF-ICE 2,451,287 WRAPPER FEED FOR WBAPPI'NG M ACHIN ES William Hoppe, Longmeadow, Mass.,- assi gnor to National Bread Wrapping Machine 00., Springfield, Mass, a corporation of Massachusetts W Application April 8, 1944, Serial No. 3Q, 152

8 Claims.

This invention relates toimprovements in wrapper feeding mechanism for wrapping Inachines of the type in which the leading end of the wrapper web is circumferentially wrapped about the article before being severed from the body of the web. In some aspects it is an improvement upon the structures shown in, and in other aspects the present application is a continuation in part of my prior applications Serial No. 454,275 filed Aug. 10, 1942, now Patent 2,- 347,560 granted May 25, 1944, and Serial-No. 434,486 filed March 13, 1942 now Patent 2,330,- 715 granted Sept. 28, 1943.

One object of theinvention is to decrease, and to make more uniform during the wrapping operation, the tension of the wrapper as it is drawn circumferentially about the article. Particularly in the wrapping of readily deformable articles such as sliced loaves of bread, prior-Wrapping machines have had a tendency to'crush the corners of the loaves. Loaves, even in the same run, vary considerably in size, and a much closer conformity of the cut wrapper to the dimensions of the individual loaf is obtained by wrapping the loaf in the leading end of the web beforeseveringthe latter. This necessitates that the article itself draw out the wrapper as required, placing some inevitable-strain upon the article. In my prior Patent 2,273,961, Feb. 24, 1942, and in the application and patent referred to above, I have disclosed the use of one or more web feeding rolls which engage the web by impositive frictional contact during at least the period when the web is being drawn out by the article, thus greatly reducing the pull which it is necessary for the article to exert. In accordance with the present improvement, the web is supplied to these frictional rolls from a second. frictional'roll, a slack take-up device being positioned between the two rolls in such a manner that the tension on the web is further reduced as will be described below. In fact this tension is almost imperceptible when the end of the web is. drawn out by hand, While there is n tendency for the web to overrun when the pull on it is relaxed.

A further. object is to. provide amachine, capable of wrapping an article. inthe, unsevered leading end of aweb,which is. capable of operation by one man who can both supply unwrapped articles to and remove wrapped articles from the machine: This result' is "greatly enhanced by the decrease of the tension on theweb, since the occurrence ofprushedioaves or-rupture-d-webs Which wou ld requirethe' presence of an operator elsewhere than at the loading and unloading station has been practically eliminated. v

I A further object isto provide a web feeding mechanism which, by reason of its 'compactfsize and since it produces practically no free slack,

can be placedbetween the superposed infeed and outfeed conveyors required for a simple nachine intended for one man operation. I

v A further object isftoimprove uponexisting mechanisms by providing for positive mining of the web at all times when'the leading end of the latter is not held by engagement with the article.

Additional objects will appear from the followingdescriptionandjclaims. Referring to thedrawings,

Fig. l is a median section through a wrapping machine including the invention; Fig. 2 is a similar view with theparts in different positions; and

r Fig. 3 is a continuation of Fig. 1 showing the wrapper supply roll; and associated mechanism; Fig. 4 is a detail of the infeed conveyor drive; and

- Fig. 5 is a view similar to a part of Fig. 3 but with the parts in different positions.

The general mechanism of the wrapping machine forming no part of the present'invention it will not be described in detail. As far as relates to the invention, the Wrapping machine comprises an infeed conveyor having ways 10 alongwhich articles, such as sliced' loav'es of bread, can'be forwarded, and 'side' -guid'es H. Ashaft l2- si1p ports the driving sprockets 13 of chain conveyors M having pushersl'i connected across thmand being suitably guided in channels I6 preferably shaped so that the conveyor has a substantially horizontal portion IT (Fig. 3) and asucceeding 'upwardly inclined portion IBthe purpose of which will appear moreiully below. Shaft |2 has a gear l9 (Fig. 4) meshing with a-gear 2|] on the shaft of the slotted member 2! ot'a Geneva drive. The roll carrying member 22- of the Geneva, geared at 23'to"a drive shaft 25, ispreferably provided with. two rolls 25 engaging-with five" radial slots inthe'memberZI.

On a pivot-J30 Figs'fl and 2) swings a carrier 29 hajing'an articlei re-c'iving piate"? .l l -side tiickere 21 sag a mem rials hem pa rmg iaiiger ":3'2.---'I hse parts may" be constructed "asm my prior applic ation S'eria'l in"). 454,275; in which the a carrier isl shi iv'v'n as being oscillated by a cam on's ha it =25 from a posing; alignedwith; the ter- 'min us of th slanting or the jinfeedcon- -veyor to an; u perhorizontal position na -line with the fioor 33 of a wrapping-'and'disoharge operation.

channel. .Along this channel, at opposite ends of the article, are located in order a top folder 34, an end folder 35 (the opposite end fold having been made by the tuckers 21) and a bottom folder 36; The channel may also contain the usual bottom and end heat sealers (not shown) and bottom and side conveyor belts 31 and 39 (Fig. 3) which serve both to hold the end .fiaps during cooling and to convey the articlesfrom the machine. The carrier has a roll 39 coacting with a spring pressed roll 46 (described in more detail below) at the entrance to the channel in order to give the final bottom flap the proper amount of tension. A knife fixed on the carrier coacts with a movable knife ,42which severs the web as in my prior application.

As previously stated, one novel feature of the invention resides in the mechanism by which the wrapper web is fed towards the carrier in the exact amount required by the progressive envelopment of the article, the term-envelopment being used for convenience to denote the passage of the wrapper circumferentially around the article as distinguished from the-making of end folds.

This mechanismwill now be described.- Areel. 59 of wrapping material is mounted between the" discharge conveyor 31 and the horizontal part H 'of the infeed conveyor, preferably on a selfcentering mounting such as is shown in the Hoppe and Roberts Patent 2,134,043, Oct. 25, 1935. The,

web w is led from the reel over a floating slack take-up roll 5: carried by the lower ends of arms I 52 mounted on a shaft 53 pivoted to the machine frame. This roll has a substantial travel toward and away from the reel totake up and yield slack in a bight formed inthe web, and is tensioned away from the reel by one or more springs 54 connecting an intermediate point of one or both arms 52 with a fixed point-55 on the machine.

The point 55 is so chosen that when the floating,

roll is in its forward position (away from the reel ;;.5i!) the spring is substantially in the line of the arms. When the roll swings towards the reel the spring tension will thus progressively increase. The importance of this will appear more fully.

below.

From the floating roll 5! the web it passes around a roll 56 preferably having a frictional surface such as a rubber and rotating constantly in the direction indicated at a surface speed at least as high as the maximum linear speed which will be required of the web during the wrapping Since the specific driving mechanism for the roll is not of importance it has not been illustrated. The web passes about half-way around the roll 56 and then travels along a supporting plate 51 which terminates above the infeedconveyor near the carriers A drag 58 of usual form rests lightly on the web, being pivoted at 59 and being tilted somewhat in the direction of travel of the web so as to prevent retrograde motion of the latter while offering negligible re sistance to its forward travel.

Near the end of the supporting plate a rollfifl A web clamp BI is mounted anism in a manner to be described. It serves to clamp the web during cutting, to hold the web against any possibility ofshifting during such times as the end of the webmay not be engaged yby the article, .and' to cooperate with thesl-ackz serves, as will appear below, to cause a length of Web to be fed outin addition to that drawn out by the article, so that the leading end of the web Will hang down in front of the next advancing article. 7

Since the web is always severed by knife 42 at a definite distance away from one bottom edge of'the article, and the amount fed out by roll 61 varies the 'length of wrapper extending beyond the opposite bottom edge, adjustment of the stroke of roll 61 will directly vary the overlap of the out wrapper edges on the bottom of the article. The present mechanism permits this adjustment to be made to scale while the machine is running. For this purpose oneor both of the arms 65 carrying roll 61 are coupled by a link 19' with a crank arm 1| extending from a shaft 12 which at one end passesthrough the side frame 13 of the machineinto an accessible po sition. Outside of the frame is a crank member 14 having a slot 15 in which slides a crank block 16. AscrewgTl is journaledin the member 15 and held against endwise movementby a collar 18 and a handwheel 19 by" which it can be rotated to shift the block intoa predetermined position as indicated upon ascale-89. The crank pin is pivoted'to a link 8! coupledt-o an arm 84 by a pivot pin 82 passing through an opening 83 in the frame. The arm 84 is pivoted to the frame at 85 and carriesa roll 86 running-in a cam 81 on shaft 25. Since the handwheel is ex osed on the outside of theframe 13 and since it is located sufiiciently close to its axis of oscillation 12 so that it doesnot have very much mot-ion, it is readily adjusted during the operation of the machine to control the amount of overlap. r V

The knife 42 and the clamp, 6| are both operated from a single cam 90 which may be angularly adjustable on shaft-.25 in order to vary-the timing of the cut and hence the length ofthe second under-flap of the wrapper. This'cam actuates a rocker 9| having separate arms 92, 93 coupled by links 94, 95 to the knife bell crank 96 and to the clamp operating arm 91 respectively. The latter coupling is obtained through a member 98 mounted on link 95 between a fixed collar 99 and a spring I00, the collar-and spring being so set that considerable spring compresand spring I00 consequently still holds the clamp against the web. This'po'sition of the knife and collar are shown in dotted lines'inli ig. 2. The

latter-position is assumed a-ssoon as the cut is over, and is maintained until thenext article to be wrapped is about to strike the Web, .so;that

there is no opportunity for the webqtobecome shifted.

It has been mentionedth at the roller 40 which 7 presses the web against theroll'39 on the car-- .v w spring re e to i -i bi c he -fi a f to proper tension. .s o tha theroll 40 may not interfere with the loaf as the carrier rises it is preferably kept in an inactive position except when the carrier is in substantial alignment with the wrapping channel. For this purpose the roll 40 is mounted on arms I05 extending from a shaft I06. This shaft also carries an arm I01 which loosely fits over a pin 108 having a spring I09 between the arm and an adjusting nut I I0. Unless prevented by some other means the spring I09 causes the roll 40 to press against the roll 30 with a pressure regulable by turning nut IIO. Shaft I06 is also provided with a rocker III carrying at one end a roll H2 adapted to be elevated by contact with a plate H3 on the side of the carrier, and at its other end loosely fits over a pin H4 having a compression spring H5 belowit. The rocker also carries an adjustable stop H6 adapted to contact a pin ill on one of the arms I05. Spring H5 is stronger than spring I09 so that normally it swings the rocker III counterclockwise. Contact of stop H6 with a pin II! also swings the arms I05 and the arm I! in the same direction, compressing the weaker spring I09. When the carrier rises the rocker is turned clockwise, compressingthe stronger spring H and leaving spring I09 free to actuate the roller 40.

A further desirable refinement consists in means for positively supplementing the action of the spring 54 on the roll 5|, so. that since the entire burden of unwinding the web from roll 50 is not borne by the spring 54 the latter can be made lighter. This further reduces the pull on the article necessary to feed out the web. Adjacent one or both of the roll supporting arms 52 is an arm I carrying an abutment I2I positioned to contact the arm 52 and move it positively away from roll 50. As shown, the arm I20 is connected by a link I22 with a lever I23 pivoted to the frame and having a cam roll I24 running in a face cam I25 on a shaft I26. The parts are so timed that during the period in which the web is not being drawn out by the articlein other words, when the clamp GI is holding the web firmlythe roll 5I will be moved away from roll so that a full amount of slack; is available for the article to draw from. The arm I20 then withdraws from contact with the arm 52 during the period when the web is being drawn out by the article.

Assuming the roll 5! to have been moved into the position of Fig. 3 either by the arm I20 or by spring 54, and that a loaf is moved by a flight I5 so as to grasp the leading end of the web between it and the backing plate 32, the action is as follows: As the loaf advances onto the carrier it will tighten the web around roll 50 as is in Fig. 1. The frictional contact of this constantly rotating roll will cause the web to be pulled against the also constantly rotating roll 56] Roll 60 acts to feed forward the web delivered by roll 56 and also to cause the feeding action of the latter by tightening the Web around it. Roll 59 assumes the heavier burden of unwinding the web from reel 50, and for this reason preferably has longer surface contact with the web than does roll 60. Either roll will of course cease forwarding the web as soon as the forward pull on the web beyond the roll is released. When the article first starts to pull on the web the slack take-up roll 5I is in its position of minimum tension and the reel 50 is presumably at rest. The initial forwarding of the web thus occurs without shock and under only slight tension. As the take-up roll is drawn to the right in Fig. 3 the tension of the web around roll 56 is increased in proportion to the movement of roll 5I, insuring ample powerto start reel 50 in rotation. As the demand for wrapping material lessens the roll 5I will tend to regain its normal position o ig. 3, decreasingthe pull on reel 50 and allowingthe latter to come slowly to rest. There is much less tendency for reel 50 to overrun in the arrangement shown than were the take-up roll to be placed beyond roll 55 rather than between it and reel 50, and the pull necessary forthe article to exert upon the web to cause it to be fed out is very greatly reduced.

I claim:

1. A wrapping machine having a substantially horizontal wrapping and discharge channel, an infeed conveyor located in substantially the same plane vertically belowsaid channel and having an upwardly inclined terminal portion. a carrier l ivotally mounted and driven to oscillate between the terminus of the conveyor and the terminus of the channel, a supply for a web of wrapping material located between the conveyor and'the channel, a rotating web feeding roll mounted between the conveyor and the channel adjacent the carrier and operating to feed the web when the latter is drawn tightly around it, a second rotatable roll positioned between thef'eeding roll and the carrier to maintain the web in an arc surrounding the feeding roll during the movement of the carrier from the conveyor to the channel, flights Oh the e e heeit ened to eeh e l h ehg mea or d i g t e ehvev te m t i e timed re a ieh. as. t e rn art u ess Q l the e r ier hen he e er s di e nt he te minus of th eeh erer a d t ol the li h conv yin each sa d a ticle n os i n to e as an a tlele'ghi the earrier moves w from the eehveyer- A. wrap n mac ine ha ng a hhst htiauy horizonta re h ng and discha e ehanne i e cl onv yor l c ted in. sub ant all t e same an e t a y l w sai chann a d. hav ng e u l inclined term nal port on. a car ie p otall unted nd driven to esei let bet e n the terminus of the conveyor and the terminus of he hanne a up ly o web f wrapping aer el leee eclhetwe n he e h ever ehdthe hannel a otat ng. eb feed n tell m u ed. between the e eye and the channe adjacent the earer nd. e ating to. feed th we when the later s awn tigh ly h fQl lld. it. a sec nd rota able e hesi ieh d etwe n. the. eedi g r and the arr er t a nta n the weh n. are surreendin he eedlhe e dur n he mo ement of t e e rler fr the eeh eye to he ehehhel flight en he eeh e r hes tiehed te onvey an a tlele ther elena meens, er d i in he eehve er termitteh l shel .v timed relet e s to. e rn! arti atter adjacen the te m nus ef. the eh eyer nd te held the fli ht eehv r ng eeh. ale artiele inposition to act as an article guide as the carrier moves away from the conveyor, means for moving the second roll towards the conveyor when the carrier is adjacent the channel to cause an additional length of web to be fed, and means for severing the web between the carrier and said roll.

3. A wrapping machine having means for enveloping an article in the leading end of a web, and means for feeding a web to the enveloping means comprising a wrapper supply roll, a first constantly rotating web forwarding roll, a slack es ehee eei elv ente the earner w en. he.

7v take-up roll around which the web passes ,be--' tween the supply roll and the first 'forwardingroll, and a second constantly rotating web forwarding roll delivering the web to the 'enveloping'means, whereby thewrapper web will be forwardedas required by the enveloping means-"but; without excess. 7 V 1 a 4. .Aavrapping machine having -.means for en-' veloping an article in the leading end of aweb, and means for feeding {a web to the-enveloping means comprising a wrappersupply roll, a first web forwarding roll constantly rotating-at afsurface speed at least equal to the maximum required of the web, a slack take-up roll around which the web passes between the supply roll and the first forwarding roll, a spring acting on' the take-up roll to increase the tension on the roll as the latter is drawn toward the supply roll, said slack take-up roll being so located that in all its positions it guides the Web to freely encircle a portion of the circumference of the first web forwarding roll, and a second web forwarding roll constantly rotating at a surface speed at least equal to the maximum required of the web and delivering the web to the enveloping means, whereby the wrapper web will be forwarded as required by the enveloping means but without excess.

5. A wrapping machine having means for enveloping an article in the leading end of a web, and means for feeding a web to the enveloping means comprising a wrapper supply roll, a first web forwarding roll constantly rotating at a surface speed at least equal to the maximum speed required of the web and located to forward the web by impositive frictional contact, a slack takeup roll around which the'web passes between the supply roll and the first forwarding roll, a spring acting on the take-up roll to increase the tension as the latter is drawn toward the supply roll,.a second web forwarding roll located to deliver the Web by impositive frictional contact .to the enveloping means, means for preventing retrograde movement of the 'web at least whenthe Web is not being fed to the enveloping means, and mech' anism positively moving the slack take-up rollfto provide maximum slack during such periodslwhe'n the web is not being" fed. "I:

6; A wrapping machine having means for envelopin'g 'an article in the leading end of a web,

and means for feeding aweb to theenve'lo'ping means comprising a wrapper supply roll",-'affirst' web forwarding roll constantly rotating atajsu'riface speed at least equal to the maximumispeed required of the web and located to forward the web by impositive frictional contact, a slack takeup roll around which the web passes between the.

supply roll and the first forwarding roll, a spring acting on the take-up roll to increase the tension as. the latter is drawn toward the supply' roll, said spring being substantially at right angles'to the line of movement of the slack take-up roll when the latter is in positionto provide maxi.- mum'slack, and a, second web forwarding'roll lo}- 8 cated tov deliver the'f'web bylimpositive' frictional contact to the -,enveloping meansei 5 1 i ,7 .;A wrappingmachine comprising..:means-;fbr envelopingtzan article in the leading endgofza wrapper web; a supply roll for the wrapper Web, a roll constantlyadriven at a surface speed at least equal to the maximum speed re'quired of the web during the wrapping operation andv 10-, cated to engage the web between the supply roll andthe enveloping means, a freelyarotatableiguide roll located to engage the :web. between the constantly Idriven roll and the. .enwrappingf means, means, for severing the web from the wrapped article, and means for shifting the guide-troll bodily prior, tothe. severance ofjthe web to cause] an vadditional length'of'web: to be fed o'u't,=said last means "i'ncludingan .oscillatablei shaft, a crank thereon, means.- connectingrsaidicrank to the guide roll for shifting the guide roll bodily,

a second crankonLthe.-oscillatable:'shaft,:and

means for actuating the second crank; one "of said cranks being adjustable in' length and 'posie tioned, Where it can be' reached and" adjusted during the operation of the machine; a .1 8. A wrapping'machine comprising a wrapping channel, an infeed stationrbelowthe .channeLLL-fa carrier movable between the channel-and the station, means for feeding wrapping material .between the station and the carrier inposition to be. picked up by an article-being movedonto the carrier,- a r'oll underneath and at the forward edge of the carrier, a spring pressed-roll mounted underneath the channel to hold the trailing edge of the wrapper against the first-mentiOned roll,

a spring means operating on the second-named roll in a direction tending to shift the rol-l -into a position in which it can-contact the first-men tionedroll, additional spring means operating on the second-named rollwith greater force than the first-named spring means and in the opposite direction, whereby the second-named roll will be held normally out of such contacting position, and means actuated by the carrier when coming into alignment with the channel toinactivate said additional spring means andthereby 'allow the first-named spring means-to shift the-second;

named roll into such contacting position.-- l

a a WIlLI'AM-HQPPE;

nEFERENoEs oITEn f ,7 The following references-are of recordinfthe file of this patent: i l v V 1. UNITED STATES PATENTS Number 'Name- ;Date

1,626,379 Armstrong Apr. 26, 1192? 1,685,146 -Bechman Sept; 25, 1928 7 1,851,295 Schmitt 'Mar.'29, 1932 2,060,501 Hopper. NOV5 Q1936 2,276,590 Petskeyes et al.' Mar; 17,1942 2,310,719 Tuthl'll eta1. 1Feb.f9,"'l943 2,330,715 ,Hoppe 1; Sept'f28; 1943..

Arelt Aug. 22, 1944

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