CA1055771A - End plug closures for shirred casing sticks and methods for making them - Google Patents

Abstract

END PLUG CLOSURES FOR SHIRRED
CASING STICKS AND METHODS FOR MAKING THEM

ABSTRACT OF THE DISCLOSURE

Improved end closures for shirred casing sticks and methods for making them which comprise inturning a predetermined amount of a casing material into a forming tube and then compressing the inturned casing material against a fixed surface to form a free floating, semi-floating or fully anchored type flat end plug which when anchored within the fore end of a shirred stick may or may not form an integral part thereof.

S P E C I F I C A T I O N
1.

Description

~ P7~ ~781-2 Field of the I~ven~ion This invention relates to improved end closures of casing material for hollow shirred casing stick~ and to method~ for making such end closures.
Background of the Invention - ~hirred food casings of flexible tublng re presently being used in ~he mea~ industry for making sausage products such as frankfurter~, pork sausages or the llke. The flexible ~lbing used for food casing 10 may be comprised of proteins, carbohydrates and the like as collagens9 alginates, stsrches or cellulosic material such as cellulo~e esters, cellulose ethers and regenerated cellulose, as well as other natural, synthetic or artiflcial material~. The casings are first prepared as hollow, th~n-walled tubes of lengths ranging from about 1~.2 to abou~ 48.8 meters or more, and then shirred and compressed to produce wha~ is eoD~only termed in ~he urt "6hirred casing sticks or strandsl' of from abou~
20 cen~imeters or less ~o about 69 centime~ers or ~or~
20 ~ - lengthO
---. The shirred c~in~ ~ticks ~re th~n packag~d and shipped ~o a food proces~or where each indi~idual stick is stuffed ~i h food em~l~ion filling the ca~ing - to its fully e:ctended length. Such casing s~ick~ may be stuffed with food emul~ion by manual or au~comatic operations. In ~h~ manual opera~ion, ~he cas~ng 8tiC~
i8 ~heathed onto a thin~ lled food stuf~ing horn , - : connected ~o a con~en~lonal val~e controll2d veg8el . . . ... . . . . .
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557 7~ 8781-2 ~illed with food emulsion under pressure, The operator may deshirr a short length of caslng at its outbo~rd or fore end to form a closure ther~at 80 as to prevent the loss of food emulsion during the filling of the casing.
Automatic machines have been developed for stu~fing or stuffing and linking of ~hirred ~ood casings - wieh food emulsions to produce ~uch produc~s as frank-furters or the like on a ontinuous bas~s. On2 such 10automatic machine, disclosed in U. S. Patent 3~115,668 to Town~end~ is capable of ~uccessively s~uffing and linking a shirred casing with food emulsion to produce a plurslity of food links on a continuo~s basls. In automatic food ~tufflng machine~ of ~11 types, and with the Townsand mach~ne in particular, the ~tuffing of the casing usually takes place within se~eral seconds with the result that the ca~ing is extended from a shirred length of 20 to ~9 centimeters ~o an ext~nded length of 12.2 to 48.8 meters or more in a matter of 7 to 30 20 ~econds. This rapid e~ten~ion of the casing during tha -stuff~ng operation of the machine require~ the casing to be esp~cial:Ly str~ng and resistant to ~earing. In addi~ion, the easing stick is required to h~Ye an end .i m --. closure 80 that ~he ~hirred casing 6tick can merely be - placed on the ~3tuffing horn of a ~tuffing machine and filled with food emul~ion without fur~her handling b~
the machi~e operator o ensure that none of the food - emul~ion e~capes from the. ~a~i~g. In practice,, a - .. .''- . - - . . -~
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~ ~ 5 57 7~ 8781-2 plurality of ~hirrad casing sticks with the fore end of each plugged or o~cherwise clo~ed, are placed in a dispensing hopper of an automatlc stuffing-linking machine. The machine o~erates such ~hat one stick at a time i~ :Eed from the hopper to clamping-aligning means that align the stickls bore with a thin-walled recipro-cating food ~tuff ing horn. The stuffing horn is re-tractabie to a startlng position aft of the casing stick positioned in the ~ligning mean~. The discharge end of the stuffing horn i8 ad~anced into the casin~ bore and mNst engage the fore end of the ca~ing ~tick to i~itially de~hirr and push the fore end about midway through an annular pas sge on a control chNck. Thereupon a pu3her at the àft end of the stick ad~ance~ to compress the caslng and seat the fore end of the casing wall into fl~tes of the chuck's passage. Before the stuffing-linking operation begins9 the casing's ~or~ end is firmly ~
6e~ted in~o and gripped by flute of the chuc~. Food :-emul~ion is th~ dispensed fr~m the Rtuffi~g horn and the chu~k is rotated ~o cooperate with linking means ~o - there~y for~ the ~illed ca~ing s~lck in~o links of pre-tetermined length which c n thereafter be suitably pro-cessed, ~f nece~sary, to produce a strand of sausage links-or the llka which, if peeled, yield skinless frank~urters or the l~ke.
Consequently, stuffing-linking machinery that opera~es in such a manner requires shirred food casing stlcks ~o hsve a plug or olosure at the fore end of ..~ .,, .. . ~-, ' ', ' , -.

1~5~77~ 8781 ~u~h sticks 80 that the ~dv~ncing ~uffing horn may engage it 80 that the stuffing horn can ~dvance ~he casing ~tick into ~he chuck to ~hereby de~hirr the ca~ing ~ithout diB80Ci-~tion of ~he closure ~d al80 ~0 effect~vely block the flow herethrough of food emulsion. The clo~ure thus aerves a8 - an ab~ment to properly initi~te sui~able filling and de-~hirring of the casi~g stick ~hile simultaneously pr~viding suitable con~rol for the ~tart of the linking opera~i~n without having any of the food emNlsi~n e~cape from ~he casing. When u~ing completely hollow ca~in~ ~ticks ~ith automatic stuffing-linking marhinery~ the operator had to plug one end of each casing by tying, twisting or insertlng an obstruction to the food emul~ion flow. Thi~ Wa8 a c08tly and time consuming operation for the food packer. Thu6 it became conventional practice to provide a casing stick :. with an end closure prepar~ddur~ng the manufac~ure of the casing rather than during the u~e of the casing nt the site of the ~tuffing and linking operatlons. Consequently, var~ous typeæ of casing clo ures, a~d methods for forming the 8ame9 have bPen discloRed ~8, for example, in U. S.
Patent 3,162,892 to Tc~nsendg U. S. ~e~t 3,274,005 to Al~ys, U. S. Patent 3,383,222 to Alsys e~ al and U~ S. :~
Patents 3,419,401, 3,5509191~ 3~564,647 and 3,570,045 - to Matecki~ ~nd in ~. S. P~tent 3~865,954 to Tum~ et al.
` Although the~e ca~ing end closures exhibi~ . -many adYantages over the manually formed clo8ure89 they -- '' __ ____ - .. ....

5 57 7~ 87~ 2 have been found to ha~e certain llmitations such as no~ being readily formable on shirring machines, being ~ifficult to control the amount of casing used in forming the end closure, being too tightly ~nchored in the bore, or being too rigid to be employed in s~me ver~ions of the automatic linking mesns of stuffing machines.
- Accordingly, it is one ob~ect of this invention to provide a new and ~mproYed method of closing the fore end o~ a shirred casing ~tick for food or other materials.
-10 Another ob~ect of this invention is to provide an improved method for closing the end of a ~hirred casing sti~k utilizing only the material of the casing in the closure.
Another ob~ect of the invention is ~o pr~vide a new and improved method for producing plug closure~
for hollow shirred sticks o. tubular casings.
Another ob~ect o th~ 8 invention is ~o provide a new ant improYed shirred food casing stick having a ~loating end closure which is integral with the easing stick-.
- Another ob~ect of this inventio~ is to provide a.new ~nd impro~ed shirred food casing ~tick ha~ing a - - ~e~i-floating end clo~ure which may or may no~ be integral - - with the ca~ng stick.
Still ,another ob~ ect of this invention is to - provide a new and improved shirrsd food casing stic~ -haYing a:~ull~ anchored plug closure to preven~ improper - - sheQthing of th~ atic~ o~to a stuffing horn and to permi~
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577~L 8781-2 internal enga~ement of the clo~ure with me~ns to de~hirr - and s~ff the c~ing with food e~Nlsion.
Still another ob~ ec~c of the invention is to provide a new and improved shirred casing ~tick with a plug closure which is not an integral part o~ the ca~ g st~ ck.
Other and additional ob~ects of the inven~cion will become apparent from the specifications, de~cription and accompanying drawings.
Summary of the Invention The inYention relate~ to a hollow shirred s~ick of ~bular caslng having an open end, also referred to as the aft cnd, and a closed end, al~o referred to 28 the fore end, said closed end c~mprisin$ a plug of com-pre~sed deshirred ca~ing o~ which a first portion is secursd to at least a portion of ~he clo~ed or fore end 6urface of the shirred stic~ with the remainder generally conforming to the bore of the shirr2d ~tick and e~tending within ~aid bore ~o as to form an annular spsce between 20 the ex~e}lded portion of said plug and the internal wall of the shirred ~3tick. Another embodi~ent of a closed end for a hollow ~hirred sticlc of ~uhular casing comprises a cylind~ical p:Lug of compr . ssed deshirred casing, haYing substantially f:Lat end ~urfaces, coaxial~y implanted within the bore of the ~h~rred ~tick and ~ubs~an~cially . ~lush Dlounted at the clo~ed or fore end thereof. The plug in ~oth of these embodiment~ could prefera~ly ~e aT~ :

ir~tegr81 par'c o the ca~i~ so a~ ~o ~fficiently and . ' .' - . .

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easily allow the fore end pleats of the cssing ~o be initially de~hirred by the advanc~ment of a stuffing horn of an automatic stuffing machine for inserting the fore end of the casing into a chuck mem~er of the machine whereupon ths pressure of the dispenfiing food or other type emNlsion oould then deshirr the r~mainder of the casing. In another em~odiment~ a plug can be pr~pared u8ing casing or some other material in a separate opera-tion and ~hen be inserted into the bore at the fore end of a shirred sasing stick having a deshirred portion of about 2 to 5 centimeters. The separately produced plug can be attached or otherwise secured to the deshirred casing at the fore end of the s~lck prior to being inserted in the bore of the casing or subsequent thereto as long as it is sufficiently anchored to the fore end of the casing stick to allow for the fore end to be initially deshirred as stated aboPe, Preferably, the portion of the separstely produeed plug which extends 8ubstantially across the bore of the casing stick should be compre~sed against the internal wall of the casing stick and then ~he deshirred portion of casing ~tick folded ti~htly into or bonded onto the end surface of the piug to for~ a secured union therewith.
- In both ~he integral and non in~eg.al plug e~bodiments, the plug ~hould be sufficiently anchored to the fore end of the cas~ng ~tick so as to permit initi~l deshirriag as s~ated above and to prevent blowout o the plug during filling of the ca~ing with food or . ' ' - ~
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~ L~5577~L 8781-2 other type emul~ion while being adaptsble BO that any - exces6 emulsion that may be trapped in the first link of the casing can be easily removedO
The invention al~o relate~ to a method for closing an end of a hollow shirred stick of tubular casing whi~h compri~es:
a) placing a hollow cylindrical forming tube into the bore of a hollow shirred Rtick of tubular casing;
- b) inturning a portion of the casing at the fore end of the shirred stic~ into 6aid forming tube;
- c) placing a relatively fixed surface against the end of the ~hirred stick containing the inturned cas ing;
d) compressing the inturned casing against sa~d fixed ~urface to form a c~mpressed plug of casing within the bore of the shirred stick; and e) removing said forming tube from the bore of said ~hirr~d ~tick.
Another method for clo~ing an end of a hollow shirred stick of tubular food casing would compri~e - steps (a) through (c~ above followed by the following step:
d'3 c~mpressing the inturned casing against - - - said fixed surface while~simul~aneously removing ~aid for~ing tube ~o as to form a compres~ed flat-end~face cylindrical plug of casing withi~ the bore of said - ~hirred seick which is tightly compressed again t the i~ternal wall o~f sald shirred ~ic~ with sufficient ':- :. - . . - ' , - -. - , .. - - -, ' " . ' " ~

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878l-2 tenacity to allow the fore end of the casing to be forcibly inserted lnto sizing-linking means of ~n ~utomatic stuffing machine.
Another f2ature of this invention relates to a method for producing plugs or closures of compressed casing, made of food casing or another type. material, for use wlth hollow shirred æticks of tubular casings which comprises:
a) implanting a fixed amoun~ of c sirlg into -one end of a cylindrical forming tube;
b) placing a relati~ely fixed surface against the end of the forming tube containing the implanted cas in8; and ~ c) compressing the implanted ca~ing against said fixed surface to form a compressed cylindrical plug of ca6ing having substantially flat end surfaces.
The compressed plug can then be firmly anchored to the plests of the internal wall of the for~ end o~
a hol~w hirred stick of tubular casing, for example, food c~sing, by being forcibly implant~d therein ~o as to pro~ide a suitable c losure hereat as described above .
To produce a semi-floating non-integral plug for a hollow shirred 8tick~ the fo~ming tube in step (a) - aboV2 i8 `prefer~lbly coaxially aligned within a larger cylindrical supE~ort tube and rec~s~ed at ~ne end by a flx~d am~unt. A fixed amount of c~sing is ~hen implanted into the recessed end of the forming ~ub~ and step~ (b) -and.(c) are performed a~ ~tated above except thst in~tead ::. 10.
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~5577~ 878l-2 of producing a cylindrical compressed plug, a mushroom type semi-floating plug is produced. Thereafter the semi-floating plug can be forcibly inserted into the fore end of a hollow shirred stick with the top or larger diameter portion of the plug being firmly anchored to the pleats of the lnternal ~all of sa~d ~hirred caslng.
A~ used herein, the terms "fore end" and "aft end" of the ~hirred casing ~tick are intended to mean the direction of shirring in the stick, the fore end being the part of the casing to be initially shirred, and the aft end being the last to be shirred. Thus, it i8 the aft end of the shirred casing stick that is fed oYer a ~tuffing ho~n BO tha~ the food emulsion dis~
persed from ~aid horn will deshirr and fill the fore end `
of the casing stick first. Typical methods and ~pparatus employed to shirr lengths of tubular casing to obtain shirred casing ~ticks are disclosed, for exam~le, in U. S. Paten 2,983,949 and 2~9&4,574 to M~tecki and U. S. Patent 3,110,058 to Marbach. -I~ ~hould be appreciated that the si~a, shape and degree o~ anchor~ng of the compressed plug~ of this invention can vary depending on the cize a~d use of the hollow shirred o sing s~icks with which it will be used.
For example, with casing stick~ ha~ing an intern~l or bore d~ameter of between abou~ 9 mm. to 25 mm.~ the cylindrical flat-end plugs of thi~ in~ention can vary ~n casing deshirred lengths bet~een ab~ut 7 cm. to about -46 cm. in length and have a di~meter sufficient 80 that 11.
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~ 0 5 57 7 ~ B781-2 the plug can be firmly anchored within the fore end of the casing stick. A plug having a deshirred casing leng~h smaller than about 7 cm. would be undesirable because:
1~ the plug ~ould not contain enough material to permit a stuffing horn of an automatic stuffing machine to advance the stick containing said plug into a chuck of the machine for proper ~ndexing therein; and 2) the plug wGuld not contain enough material in which to maintain integrity or securement to the stick and this could result in blowouts and/or lea~age during stuffing of the 8ticko A
plug length larger than about 46 cm. would be undesirable because: 1) the plug would have too much ma~erial and thereby ba too largP and rigid to cooperate satisfactorily with the link~ng means o~ an a~omatic stuffing machine;

2) too much material in the plug prevent~ effective and efficient stripping of emulsion from the fir~t (par~ially filled) link; 3) leads ~o ineffective and wasteful u~e of casing matcrial; and 4) ca~ses the plug to be anchored more secure b to the bore than desirable.
- Preferably, a shlrred cellulose casing stick having an outsid2 diameter of abou~ 23 mm., an inside diameter of about 13 mm. a~d a shirred length of about 50 cm. (~ deshirred length of abou~ 50 m.) can use floating plu~s having a ~ .
dashirr d casing length o~ 25 cm. c~mprea~ed to a plug length o~ about 25 mm. When using a ~mi-floating plug for the ab~ve ~lzed casing7 the preferred c~mpres~ed casing length would be about 20 mm. and whe~ using a fully anchored plug~ the preferred compressed ca~ing length .
1~ . ' ~5577 would be abou~ 15 mm.
The cssing lengths of the compres~ed plugs of this i~vention can vary depending on the end use of the casing ~ticks in which they will be used. However, for general application ~S2, preferable de~hirred lengths of the plug8 should be between about 20 cm. and about 36 c~O
The diameter of the sm~.ller cylindrical portion of the floating plug can vary depending on the bore and -end use of the ~hlrred rasing s~lck. The benefits of employing a floating end plug are that it permits ease and uniformity of deshirring ~he fore end of the ~tic~
in whlch it i~ used while it also provides a softer or more resilient plug for minimizing difficulties with the linking m~ans of automatic stuffing machines.
The size snd shape of the 6emi-floa~ing plugs - of this Lnvention can vary whereby the length and diameter of the floating segment can be a~ described above for the floating end plug while the length and diameter of the anchored portion can be as de~cribed above for the 20 f lat end cylindrical plug .
- - - A common festur2 of all the above shaped plugs : :
i8 th~t each is pro~ided with a flat end facing the aft end of the casing stick thereby providing a more reliable pressure receipt poin~ for the fore end of the food emul~ion-stuf~ing horn of commercial ~tuffing machines such as disclosed in the ~bove-idcntified patent to Townse~d. This i~ an lmportant feature since at the star~: of the stuffing cycle5 the stuffing horn i6 advanced . : - - . - . . -, .
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through the bore of an indexed casing to engage the plug posieioned at the casing's fore end to introduce it into a rotating annulus or chuck on the machine which cooperates with linking means for automatically llnking the stuffed casing into predetermined length~ after it i~ filled with food emulsion, The plug5 of this inventi~ in addition . to having the necessary mechanical integrity to withstand the ini~ial insertion of the casing into the chuc~ member9 possess the neces~ary hydraulic integrity to prevent ejection of the food emulsion during the stuffing opera~io~
while also being susceptible to being ~tripped upon com pletion of the stuffing and linking operation 80 that any food emulsion contained therein can be ssl~aged.
Illustrative embodiments of the invention are 6hown in the drawings wherein:
Figure 1 is a view partially in elevation ~nd partial b in section of a hollow shirred s~ick of tubular food cssing with a portion of the casing deshirred at it~
fore end~
Figure 2 is a view of the hollow shirred ~tick of F~gure 1 with a forming tube containing a pscking rod - dispo8ed-wi~hin the bore of the ~hirred stick.
. Figure 3 is a ~iew of ~h~ ~hirred ~ticX assem~ly in Figure 2 with an in~erti~g rod positioned to ini~iate the inturning of the de~hirred casing into the bore of the form~ng ~u~O
Figure 4 i8 a ~ie~ of the shirred ~tick as~embly of Figure 3 with the inverting rod moved to a position . .
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~781-2 ~55~
whereby the de~hirred CRSing shown in Figure 1 along wi~h a ~ec~nd portion of deshirred casing is Inturned into the bore of the forming tube.
Figure 5 iQ B ~iew of the shirred stick assembly of Figure 4 with the inverting rod removed and a fix~d ~urface po~itloned again~t the fore end of ~he shirred - stic~.
Figure 6 is a view of the shirred stick asse~bly of Figure 5 with the packing rod positioned ~uch tha~ the 10-- . inturned casing i~ compressed ag~inst the fixed ~urface.
Figure 7 is a ~iew of the shirred stic~ assembly of Figure 6 ~ith the forming tube moved to a position of alignment with the packing rod.
Figure 8 iB a view of the shirred stick as~embly of Figure 7 with the forming tube and packing rod being : -moved to the aft end of the shirred caQing. ~.
. Figure 9 is a view of the shirred stick of Tigure 8 after the floating plug is formed and the forming tube and packing rod remo~ed.
- Figure 10 is a Yiew of a shirred stick assem~ly similar to Figure 6 ~xcept tha~ the forming tube i5 - recessed at the fore end o the shirred s~ick.
-Figure 11 i8 a view of the shirred sticlc of Figure 10 after the semi~floAting plug i8 formed and the form~ng tube ànd packing rod removed. - -. Figure 12 is a ~iew of a shirred stick assembly : . . similar to Figure 10 except that the form~ng ~ube is :-- . shown in a po~ition of being removed as the packing rod - , ' . 15.
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~j5~7~ - 8781-~
is advancing to the fore end of the casing~
Figure 13 is a view of ~he shirred stick of Figure 12 aftPr the fully anchored plug ~ 8 formed and the forming tu~e and pac~ing rod removed.
Figure 14 is a view of ,a portion of severed de~hirred ca~ing implanted within ~ formlng tube and sh~wing a fi~ed s~rface and packing rod in position to initiate compres~ion of the casing.
~ Figure 15 i8 a Yiew of ~ flat-end cylLndrical plug formed using ~he as8emb1y and material ~hown in ~igure 14.
Figure 16 i~ a Yiew of a portion of ~evered de8hirred casing implanted within a forming tube which is coaxially mounted within, and recessed ~rom, one end of a supporting tube and showing a fixed surface and packing rod in position to initiate compression of the :~
casing.
Figure 17 i~ a view of a semi-floating plug formed using the assGmbly and material shGwn ln Figure 16.
Figure 18 is a ~iew of a shirred stick assem~ly similar to Figure 6 except that the formi~g tube is e~t~nded outside the fore end of th2 ~hirred casing.
- Referrin$ in detall to ~igures 1 through 9 - thcre i~ 8hown a holl~w ~tic~ of tubular food casing 10 having a deshirre~ first length 12 at the fore end thereof. :~
A orming or pack sleeve 14 i8 ~hown di~po~ed within the .
bore of casing stick 10 substantially flush mounted to the fore end of ca ing s~ick 10. A reciproeating pack .
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~ S 5~ 7 ~ 8781-2 rod 16 ~re~iprocating means not shown), secured to ~upport member 18, is positioned with~n the bore of sleeve 14 and is adapted to have a clo~e 31ide fit therein~
~y subseantially elimina$ing any clearance between pack rod 16 and the intern~l diameter of sleeYe 14, wedging of casing material between pack rod 16 ~nd sleeve 14 is effectively prevented during the compressing operation by these c~mponent~ as will be de~cribed below. Pack rod 16 i8 provided with a conduit 20 to effectively equslize the air pressure in ~he chamber formed withln the bore of ca~ing ~tick 10 as the pack rod 16 is ad~anced or retracted from said bore before or af~er c~mpre~sing~
respectively, the plug at the fore end of casing stic~ 10 against a fixed ~urface.
With ~he de~hirred length 1~ of casing stick 10 posieioned to occlude or ob~truct the bore at the fore end of c~sing ctick 10 as ~h~wn in Figure 3, an inverting rod 22, ~xially aligned with orming sleeve 14, is ~d~anced into said sleeve 14 a predetermined distance short of contac~ with pack rod 16~ During the insertion of inverting rod ~2, de~hirred length 12 and a ~econd de~hirred length 24 which is concurrently deshirred by the ad~ancing invertlng rod 22, are inturned into sleeve 14 as sh~wn in Figure 4. T~e amount of each of these deshirred lengths 12 and 24 can vary depending upon the distance advanced by ~nverting rod 22 and the density and leng~h of the closure plug desired.
... Upon removal of in~erting rod 22, 8 rela~ively .
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~S57~L 8781-2 fixed surface 2~ i~ placed against the fore end of casing stick 10 as shown in Figure 5 and then paek rod 16 is ad~anced to compress and comp~ct: the inturned casing leng~hs 12 and 24 into a floating closura plug 28 as shown in Figure 6, The clo~e 81.ide flt between pa~ rod 16 and the bore of sleeve 14 pre.vents the casing lengths 12 and 24 from being wedged between members ~6 and 14 and thereby effectively allows pack rod 16 to impart a flat-end surface to the compressed plug 28.
Forming sleeve 14 is then retrac~ed from compre~sed plug 28 until aligned with pack rod 16 which remains engaged with said plug 28 ~s shown in Figure 7~ Thereafter pack rod 16 and forming sleeve 14 are concurrently with~
drawn from the bore of casing stick 10 and fixed surface 26 ~ removed as shown in Figure 8. Conduit 20 in pack rod 16 functions to equalize the air pressure formed in the chamber of the bore of casing 10 thus preventing the plug 28 from being drawn ~urther into ~he bore by a vacuum which would normally be oreated in the chamber upon remo~al of pack rod 16 from casing stick 10. Once pack rod 16 . and sleeve 14 are rPImoved~ a casing ~tick 10 remains ha~ing a floating end closure 28 at its fore end as shown ln - Figure ~0 ~ Figure 19 shows sn arrangment of components as in FigurP 6 which use~ the s2me reference numbers for iden~
members. The only diffe2~ence 15 that forming sleeve 14 is ~hown displaced a predeter~qined distance x from the fore ~nd of ca~ing stick 10 eo th~it d~ring compaction of the .' ' , ',' ''-' ' - :
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1~ 55~P7~ 8781-2 inturned casing lengths 12 and 24, ~ portion of plug 30 will be firmly anchored to the pleats comprising the bor~
of casing stick 10. The pack rod 16 and sleeve 14 are removed as discussed above leaving a caslng stick 10 ha~ing a semi-floating end closure 30 ~t its fore end as - shown in Figure 11. A st ted above, the distance x of semi-floating plug 30 can vary as l~ng a~ it exhibits a sufficient degree of tenacity or anchoring to the internal wall of casing ~tick 10 toforce the fore end of the c~sing stick into sizing-linking means of an automatlc stuffing machine.
.Figure 12 shows an arrangment of components as in Figure lO which uses the same reference numbers for .
identical members. The only difference is that as pack rod 16 advances to compact caslng lengths 12 and 24, forming sleeve 14 is concurrently retracted so that plug 32 is formed ~ully anchored to the fore end of casing stic~ 10.
Upon removal of pack rod 16 and sleeve 14 after compaction of casing lengths 12 and-24, a casing stick 10 remains ~0 which has-a fully anchored, flat-end-face cylindrical plug 32 at i~8 fore end as shown in Figure 13.
It is 21so to be under.tood that the forming - - tu~e 14 could exteRd outside the fore.end of casing 10 aQ sh~wn ~n Figure 18 80 that a plug 34 coul~ be formed -- ou~3ide casing lO using pack rot l~ and.then inserted in~o the bore of caaing 10 to prodluce a closure 28 shoun, for example, in Figure 9.
~Referring in detail to~ Figures 14 and 15, there . ' .''-',--', ', . ' ~ .
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~ 5 ~ 7~ 8781-2 is sh~wn a rerlprocating p~ck rod 40, Recured ~o support member 42, positioned within the bore of a formin$ sleeve ~4 and adapted to have a closP s:Lide it within said bore for the reasons mentioned abo~e. Pack rod 40 also ha~ a conduit 46 for the reasons advanced above. A relati~ely fixed surface 48 is positioned against ~che end of the forming sle~ve 44 once a predetermined amount of ~evered deshirred ca~ing 50 is implanted within said end of sleeve 44. The de~hirred ca~ing 50 can be implanted in the bore of sleeve 44 in any convenient manner ~uch as disclosed with reference to Figures 4 snd 5 w~ereby an inverting rod ~s employed. Once cssing 50 ~s dispo~ed in sleeve 44, pack rod 40 is ad~anced to compact the casing 50 againRt fixed sur~ace 48 thereby forming a cylindrical plug ha~ing flat end faces as ~h~wn in Figure 15. This cylindrical plug can then be forced fit into the fore end o~ a casing 3tick so that it can become fully anchored therein as ~hown in Figure 13.
To form a semi-floating plug as sh~wn in Fi~ure 17, . he cGmponents of Figure 14 can be u~ed wi~h the addition of a support tu~e 54 co~x~ally ~unted ou~slde ~f formlng 81eave 44 88 sh~wn in Figure 16~ Forming sleeve 44 also ha~ to be recessed or spaced a predetermined distance x frcm the fi~ed surface 48 ~o that when p ek rod 40 i8 ad~anced ~o compact casing 52, A portio~ of the plug ~o formed will be ~uitable for being forcet fit into the ore end of a casing ~ ick ~hexe it can be f~rmly anchored therein a~ sh~wn in Figure ll. All that is required i8 - . 20 L
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, . ' ' ' ' ' - '. '. . .'' ''' .'. '' : ' ' . ' . ' : ' ~ SS~ 878l 2 tha~ the portion x anchored into the bor~ of a casing stic~ have a degree of tenacity or anchoring ~o the ln~ernal ~all o the bore so as to allcw th~ fore end of the casiDg stick to be forcled into sizlng-linking ~eans of ~n automatic ~tuffing machine wlthout damaging either the casing or the sizing-link~g m~an~O
When the plugs are fabrica~ed in a separate operatlon a~ described in con~unction with Figur~ 14 $o 17, they can be mæde of Rny ~uita~le material tha~ will be co~pa~ible with the material of ~he ca~ing.
It i8 to be understood that componen~ parts used in making the plug8 of this i~vention, whether in~egral with the cQsing stic~ or not, csn be made of ~ny suitsble material capable of withstanding the pressure used to compact and form the plug8. It i9 thus apparent that e~ch component part may be made of the sæme material or each may be made of a different material.
EXAMPLE I
U~ing the procedure outlined ~n Figures 1 through 9, ~ 0.711 ~m. :Lnch th~ck cylindrical ~tainle~s ~te~l forming sleeve ha~ing a~ O.D. of 12.8 mm. wa~ inserted ~i~hin the bore of a hollc~ cellulose caslng stick measuring - 1~,7 mm. I~D. and 22.8 mm. O.D. A highly polished 11.2 mm.
diameter tainl~ teel pac~ rod, with a 4.7 mm. axial pa8sage9 wa~ di~posed wlthin the bore of ~he orming xleeve.
Afte~ a 12.7 c:m. inch lengt~ o~ casing was deshirred, a highl~ poli~had 6.35 mm. di~me~er s~eel inverti~g rod was axially adYanced i~to the forming sleeve for a --, - . . .
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~ 781-2 ~5577~11 distance of 20.32 cm" Upon re~oval of the inverting rody a rigid flat surface was positioned agalnst the fore end of the ca~ing stick co~taining the inturned deshirred ca~ing and then the pack rod was a~7anced ~co compact the inturned ca~ing thereby formis~g a floating plug appro~:imately 25.4 mm. l~ l'hereafter ~he sleeve, pack rod and rigid flat surfacle were removed leaving a casing s~cick having an int2gral floa~ing end closureO
Ths closed end casing 8tick wa3 then placed in a con~ren-10 tional type hopper which fed the 6tlck ~o a stuffingand lir~cing machine as de~cribed in U. S. Patent 3,115,6680 The ca~ing st~ck performed better than available comme~
cial ca8is~g ~tick in that the casing ~tick had a plug ~hich ~as fabricated from a predete~mined fixed amount of casing material ~hich wa~ adapted or easy and efficien~
atrippirU~ while being ~ofter or les~ resilient there~y bei~g a`dmirably suited for cooperation with the slzln~-link~ ~ean~ of the automatic stuffing machine.

~ U~ g the proce~ure ou~lined in Flgure ~ thr~ugh 11, a 0.711 ~, thick cylindrie 1 ~tainless steel orming slee~e, ha~ing ~ O.D. of 12.8 m~ was in~erted wit~in - the bore of a c~llulose hollow casing stick measuring 13.7 m~0 I.D. and 22.8 ~. O.D. A highly poli~he~ 11.2 m~0 diameter ~taillle3s steel pack rod? with a 4~ mm. axial pas~age, wa~ di~po~ed wi~hln the bore o:f the forming ~leeve.
After a 15024 em~ inch lèngth of ca~Lng wa~ deshirred and wi~ the forming sle~ve recesse~ abou~ 12~7 mmO rom - : 22.
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5 57 ~ ~ 8781-2 the fore end of the caRing s~ick, a highly polished 6.35 mm. diameter steel inverting rod Wa8 axially ad~anced intc the forming sleeve for a di.stance of 15.24 cm.
Upon removal of the inverting rodl a rigid flat surface was positioned against the fore end of the casing stick con-taining the ~ntu~ned deshirred casing and then the pack rod was advanced to compact the inturned casing thereby forming a semi-floating plug having an anchored portion 12.7 mm. long and a ~loating portion 12.7 mm. long.
Thereafter ~he sleeve, pack rod and rigid metal flat surface were removed leaving a casing stick having an ln~egral semi-floating end clo~ure, The closed end casing stick was then plaeed in a con~Ten~ional type hopper which fed the stick to a BtUf~ing ~nd linking machine as described in U. S.~Patent 3,115,668. Th~ casing stiok performed better than available commercial ca!~ing sticks in that the ca ing stick had a plug which was fabricated from a predetermlned fixed 2mou~t of casing ~aterial which was adapted for e~sy alld e~icient stripping while 20 be~ng ~ofter and le88 res~lient thereby being adlm}rably su$ted or coop~eration with the ~izing~linking means of ~he automa~ic stu~fing ~achine.
It i~ thus evident f~om che v~rious embodiments shown in the drawings and from ~he axamples ~hat a ree-floating plug i~ o~e ~hat fo~ms an integral par~ of ~he casing ~uch that the plug i~ secured at the fore end of the intarnal wall of the ca~ing b~ the portion of the deshirred casing that i8 common to the plug and the oaRing. A

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~ 35577~lL 8781 -2 sem~-floating plug i 02le that i8 or i8 not int~gral with the casing and ~hich ha8 a compressed por~lon of the plug tightly ~ecured to the pleats at the fore end of the interr~l wall of the casing.
It i8 to be understood that other modificAtions and changes to the preferred embodimen~s of the iIlvention - here~n shown and described can al~o be made by a per~on 8~illed in the art witho~t departing from ~he 8piri~
and 8cope of the inYentioTl.

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Claims

WHAT IS CLAIMED IS:

1. A method for making semi-floating compressed casing plug closures for hollow shirred sticks of tubular food casing comprising:
a) coaxially disposing a forming tube within a support tube in such a manner that the forming tube is recessed within the support tube at one end;
b) implanting a fixed amount of deshirred casing withing the recessed end of the forming tube;
c) placing a relatively fixed surface against the end of the support tube wherein the forming tube is recessed;
d) compressing the implanted casing against the wall of the fixed surface to form a compressed plug of the casing having substantially flat end faces; and e) removing said plug from the forming and support tubes.

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