CA1049921A - Apparatus for severing thin-walled tubing on a mandrel - Google Patents

Abstract

APPARATUS FOR SEVERING
THIN-WALLED TUBING ON A MANDREL

ABSTRACT OF THE DISCLOSURE
Apparatus for automatically severing flexible, thin-wallet tubing of indefinite length into a plurality of segments comprising in combination means for advancing a continuous length of thin-walled tubing about a mandrel; a restraining member adaptable to restrain the advance of the thin-walled tubing at a predetermined position on said mandrel intermediate the ends of the tubing; tensioning means adapted for engaging the thin-walled tubing that has advanced be-yond said restraining member after said restraining member restrains the advance of the tubing and for tensioning said tubing about said mandrel intermediate said restraining member and said tensioning means; and at least two severing means mounted uniformly about said mandrel and adapted for being radially moved into and out of severing engagement with the thin-walled tubing about said mandrel intermediate said re-straining member and said tensioning means.

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

1.

Description

10499Zl The present invention relates to thin-walled tubular material and more particularly to apparatus for severing a thin-walled flexible tubular material of indefinite length advancing about a support mandrel, into a plurality of pre-determined length segments of the tubular material.
In general, small diameter, flexible, thin-walled tubing is prepared from a wite variety of different materials in continuous indefinite lengths. $he tubing, usually formed-by extrusion may be required to undergo an additional series of treatments, such as~ for example purifying, drying, curing and the like, that may be necessary to attain desired prop-erties prior to storage and shipment. It is also frequently desirable, or even required, that the tubing be supplied in predetermined lengths that are shorter than may be technically or économically feasible to prepare directly from a contin-uously operating extruder.
Collecting continuous, indefinite lengths of tubing in a flattened condition on reels, and cutting measured lengths therefr~m with square cut ends is an expedient way of handling the problem. Howeves, measured lengths of flattened tubing, cannot be continuously filled, as is required in certain applications such as, for example in preparing a wide ~ariety of processed food products.
In the food casing and processing industry, small diameter, thin-walled flexible tubing has, for a number of years, been prepared in a pleated and compressed form c~mmonly called shirred casing sticks, wherein a continuous measured

2.

10499Zl length of as much a8 12 meters or more of tubing is co~pressed into a tubular ~trand of about 15 cm. that can then be readily continuously stuffed using automatic stuff~ng apparatus. It is highly tesirable that the ends of the measured lengths of casing should be cut square and have no tab ends to obstruct the bore of the shirred casing stick. Obstructions in the bore or tab ends which occlude the bore, can interfere with a filling tube member typically u~ed in automatic stuffing or filling equipment and cause breakage or damage of the casing stic~.
Continuous lengths of tubular food casings may be prepared from materLals such as cellulose, regenerated cellulose, collagen, alginate and the like and shirred casing may be prepared therefrom using any one of a number of methods and apparatus as, for example described in U.S.
Patent 2,983,949 (Matecki), 2,984,574 (Matecki), 3,110,058 (Marbach), 3,158,896 (Marbach) and 3,704,483 (Urbutis, et al).
For purposes of economy and efficiency, shirred casing sticks containing predetermined lengths of casing are 2n made available to food processors. In s~me instances, obtaining shirred casing sticks which contain substantially equivalent lengths of tubular casing is difficult since the materials from which these tubular casings are fabricated exhibit properties that render them difficult to regulate, control and measure as they are being shirred, and particularly when they are being continuously shirred. Typical methods and apparatus for measuring or otherwise controlling the length ~., .
, . 10499Z~
of the tubular materisl ln the shirret casing stick are dis-clo~ed, for example in U.S. Pstents 3,594,855 (Urbutis),

3,110,058 (Marbac~), 3,741,779 (Urbutis et al).
When a pretetermined length of tubular casing has been shirred on a shirring mandrel, sepaxation thereof from a supply of said casing is desired 50 that individual sticks of compressed, shlrred câsing can be prepared and then removed from about the mandrel. Some typical methods of 3evering a length of shirret tubular casing from the casing supply that are known are tescribed in U.S. Patents 3,110,058 (Marbach) and 3,112,517 (Ives).
The atvent of automatic stuffing machines, such as described in ~.S. Patent No. 3,191,222 to Townsend, has adted other important factors to the quality requirements of shirred casing sticks. In U.S. Patent 3,471,305 to Marbach, for example the importance of the integrity of the ends of shirred casing sticks is disclosed in order to prevent breakage of ~ ;
the casing stick during operation of the automatic stuffing equipment by the food processor.
In accordance with the present invention there is pro~idet apparatus for automatically severing thin-walled tubing of indefinite length into a plurality of segments comprising in combination: a support mandrel; mesns for àdvancing a continuous length of thin-walled tubing about said mandrel; a movably mounted restraining member adaptable to restrain the advance of a thin-wallet tubing at a pre-determined position on said mandrel; tensioning means adapted ~.. . .
., , .. ~ .~ , .

lO~99Zl for engaging a thin-walled tubing that has advanced beyond said restraining member position about said mantrel after said restraining member restrains the advance of the tubing and for tensioning tubing about ~aid mandrel intermediate said restraining member and said tensioning means; and a plurality of severing means movably ~ounted abouP said mantrel having means for being traversed into and out of sever~ng engagement with thin-walled tubing about said mandrel intermediate said restraining member and said tensioning means.
There i8 also provided a severing apparatus for tubular ~aterial ~heathed about a support mandrel comprising a plurality of blade holders having severing blades mounted on said holders tisposed in a substantially planar arrangement about a mandrel and adapted to be.reciprocated to and from the surface of said mandrel, each of said severing blades being pivotably mounted on a blade holder and having two spaced apart tubing engaging edges, the bisector of the angle subtended by said edges on said severing blade defining the pivot point for said blade, and means for reciprocating said blade holders and severing blades into and out of severing engagement with a tubular material sheathet ~bout said mandrel.
In an alternate embodiment of the invention, the blade holders are provided with more than one blade, such as a pair of blades each pivotally mounted on a blade mount clevis, said clevi~ being in turn pi~otally centrally mounted on said blade holder, each of said blades having two spaced apart ~0 ~9 9'~
angularly dispo~ed tubing engaging edges, the bi8ector of the angle subtended by ~aid ed8e~ on ~aid blade defining the pivot point for said tubing engaging blade, to provide in combination, a free-floating ~elf-centering severing engagement with a tubing material ~heathed about said mandrel.
The method ant apparatus of the invention will become more clear when considered together with the accompanying drawing which i8 set forth as being merely illustrative of the invention and i8 not ~ntended to be limitative thereof and wherein:
Fig. 1 is schematic side ~levation view, illustrating one embodiment of the appaxatus of the invention.
Fig. 2 i~ a schematic perspective view, part in section, illustrating one embodiment of the apparatus of the invention.
Figs. 3 to 8 are enlarged, fragmented side views, part in section, schematicaly illustrating sequential oper-ation of the components of the apparatus shown in Fig. 1 and Fig. 2.
Fig. 9 is an enlarged fragmented front elevation view of the casing severing members shown in Figs. 1 to 8, with the uppes blade holder shown partly in section.
Fig. 10 is side elevation view of the lower blade holder shown in Fig. 9.
Fig. 11 is a front elevation view partly in section taken along line 11-11 of Fig. 10.
Fig. 12 is a front elevation view of the blade mount shown in Figs. 9, 10, 11.

Fig. 13 i3 a front elevation view Qf the cutting blade ~hown $n Figs. 9, 10, 11.
Turning now to the draw~ng, where~n llke reference numerals denote like parts, there i~ shown in Fig. 1 a shirring apparatu~, generally des~gnated by reference numeral 10 which can be the same a~ or similar to the shirring apparatus disclosed and described in U.S. Patent Nos.
2,983,949, 2,984,574, and 3,115,669 all to Matec~i. Shirring appara~us 10 generally comprises a hollow mandrel 12 which is positioned and alignet by means of clamps C and K to be substantially central to a shirring means, denoted by letter S. As disclosed and described in the above-identified U.S.
patents to Matecki, the shirring means S consists of three cogged wheels 18 axially positioned about hollow mandrel 12 which wheels serve to grip, pleat and advance successive portions of a continuous length of inflated tubular casing 14 along hollow mandrel 12. Clamps C and K are equipped with . mating ports (not shown) which lead to the bore 20 of hollow mandrel 12 so that air can be admitted continuously through the bore 20 of hollow mandrel 12 to inflate a continuous length of tubular casing 14 as it is advanced to and through the shirring apparatus disclosed and described in U.S. Patent 3,590,422 to Matecki.
A pair of rotatably driven belts 16 is positioned forward of the shirring means S to engage a continuous length of inflated tubular casing 14 and advance ~t over and about the hollow mandrel 12 to the shirring means S. A holdbac~

10~9~
or compacting ~eans ~imilar to that described in U.S. Patent No. 3,594,855 to Urbutis i9 posleioned downctream of the shirring means S. The holdback means comprises a pair of driven belts 19 that are generally advanced in the same direction as the advance of shirred tubular casing 17 and act to provide a continuous retarding force to the shirret casing 17 to compact it as it i~ advanced along and about the mantrel 12.
Referring now to Figs. 1 and 2, a restraining member 51 is pos~tioned above the mandrel 12 ad~acent to the discharge end of ~he holdback or compacting means 19.
The restraining member 51 i8 vertically secured to the end of the piston rod of reciprocally operating cyl~nder 58 that is mountet on the frame of the shirring apparatus 10.
A carriage 30 is slidably mounted on a pair of spaced guide rods 32, 32' secured to the frame of shirring apparatus 10. One end of carriage 30 is securet to the piston rod of cylinder 36 that is mounted on the frame of the shirring apparatus 10. An upper gripping finger 63 is connected to the piston rod of operating cylinder 62 which is ~ecured to carriage 30 vertically aligned above mandrel 12. A lower gripping finger 65~is connected to the piston rod of operating cylinder 67 which is secured to carriage 30 vertically aligned below mandrel 12.
Also secured to the frame of the shirring apparatus 10 are a pair of opposed casing severing members shown generally as 21 and 23 aligned about mandrel 12 and located iO ~9 9'~
at a station downstream from restraining member 51. For purposes of illustration only, ca~ing severing me~bers 21 and 23 are shown operating in the same plane as restraining member 51 and gripping fingers 63 and 65. However, to provide for passage of gripping fingers 63 ant 65 traversing along the axis of mandrel 12 secured to carriage 30, the plane of operation of casing severing members 21 and 23 should preferably be at an angle different from the vertical plane of operation of gripping fingers 63 and 65.
A typical operation of the apparatus of the in~ention will now be described and will be more readily understoot when considered with the accompanying drawing.
As described in U.S. Patent No. 3,594,855 to Urbutis, feed belts 16 (Fig. 1) connected through various trive means and meshing gears provide the means by which a continuous length of inflated casing 14 is determined and measured as it is being advanced by feed belts 16 to the shirring means S. Further as described in U.S. Patent 3,594,855, cam 50 (Fig. 2) is caused to rotate at one revolution for each length of casing 14 measured by feed belts 16 and actuation of the casing severing cycle of the present invention is readily regulated and controlled thereby.
- The single lobe of cam 50 (Fig. 2) contacts pilot air valve 54 to initiate the start of a casing severing cycle and successively actuate the operating valves, pistons and controls associated w~th the severing means of this invention.

10499Z~
Referring now to Figs. 1 to 8, actua~ion of pilot val~e 54 by c~m 50 (Fig. 2) operate~ line valve 56 to pressurize air cylinder 58 atvancing restraining member 51 towarts mandrel 12 to engage shirret casing 17 advancing from holdback belts 19 on mandrel 12, and thereby restrain the further advance thereof during the cycle required to separate, sever and compress a predetermined length of shirred casing from continuous supply. S~multaneously, pilot valve 54 operates line valve ~0 to pressurize cylinder 62 and advance upper gripping finger 63 to engage the shirred casing 17 on mandrel 12 downstream of the position of restraining member 51. This establishes the condition illus~
trated in Fig. 3.
Actuation of pilot valve 54 by cam 50 also actu-ates valve 34 to pressurize the rod ent of cylinder 36 advancing carriage 30 along slide rots 32, 32' downstream from the position of restrain~ng member 51, illustrated in Fig. 4.
A~ shown in Fig. 2, camming members 40, 41 and 2042 are ad~ustably mounted on carriage 30 on a foot member 38 in three different planes parallel to slide rods 32, 32'.
As carriage 30 is advanced, a short distance (about 3 cm.) along ~lide rods 32, 32' from the starting position shown in Fig. 3, cam member 40 engages and actuates valve 45 to pre~surize cylinder 67. Lower gripping flnger 65 is thereby upwardly advanced into gripping engagement with shirred ca~ing 17 on mandrel 12 generally opposed, ~o upper gripping 10. - ~

lO~99Z~
finger 63 as shown ln Fig. 4. The advance of carriage 30 w*th gripping finger3 63 and 65 in gripping engsgement with shirred casing 17 separates the pleats or deshirrs the casing intermediate restraining member 51 ant gripping fingers 63 and 65 ~Figs. 5 and 6).
Carriage 30 co~tinue~ to be advanced along slide rods 32, 32' by cylinder 36 to a station approximately 12 cm. from the starting position (Fig. 6) where camming member 41 on carriage 30 (Fig. 2) engages and actuates valve 46 to operate opposed casing severing members 21 ant 23. Air i8 thereby s~multaneously admitted to cylinders 76 and 78 whereby upper and lower blade holders 77, 77', respec-tively, are radially advanced toward mandrel 12 into severing engagement with the deshirred casing 16 (Fig. 7). A portion of the casing 16 is thereby scored and/or cut uniformly at a plurality of points about the circumference thereof. It is important that the deshirre~ portion of casing is scored and/or cut at four or more, and preferably at, at least eight points substantially uniformly about the circumference of the mandrel 12 to obtain a suitable substantially "square-cut" end. It would be apparent that the more points about the circumference of the tube that may be scored and/or cut, ~ .
and then tension separated in accordance with the practice of the invention, the more uniform will the separated edge thereof.
The carriage 30 continues to be advanced along ~.
slide rods 32, 32' by cylinder 36, thereby further advancing 11 .

iO499Zi upper and lower gripping fingers 63 and 65. The casing 16 intermediate restraining member 51, severing members 21 and 23 and gripping finger~ S3 and 65 i9 ten~ioned acro~s the scored and/or cut points about the circumference of the tubular ca~ing until the casing ~g severed and separates into segments containing predetenmined lengths of casing as ~hown ln Fig. 8. The carriage 30 is advancet further a ~hort distance (about 6 cm.) until cam member 41 on the carriage 30 engage and actuates valve 47, (Fig. 2) to provide pilot air pressure to reverse valves 56 and 46, thereby releasing air pressure on ass~ciated cylinders 58, and 76, 78 respectively, to retract restraining member 51 and severing means 21, 23. Restraint on the advance shirred casing 17 is thereby removed permitting its unimpeded advance along mandrel 12 from shirring passage S.
Carriage 30 is caused to continue to atvance with : the upper and lower gripping fingers, 63 and 65, engaging the severed casing 15 and advancing it along the mandrel to a station about 60 cm. frcm the starting station where it is positioned to be compressed by compressor anm 25 (Fig. l).
Near the end of the stroke of carriage cylinder 36, cam me~ber 42 mounted on carriage 30 (Fig. 2) engages valve 48 to provide pilot air pressure to reverse the valves 34, 45 and 60 controlling associated cylinders 36, 67 and 62 respectively, which thereby pressurize~ the piston end of cylinder 36 reversing the direction of carriage 30 and retracts upper and lower gripping fingers 63 and 6S, resulting i~ all element9 of ehe severing device eo r-rurn eo eheLr 12.

~ .

0 ~9 9 2~
re~pective ~tart po~it~on~ for the succeeding casing sevesing cycle. As the ca~riage 30 i~ being returned to the start position, cam member 41 actuate~ ~alve 49 (rever~e tirection actuation) which operates an appropriate air cyl~nter (not shown) to drop compressor arm 25 onto mandrel 12.
When compre~sor arm 25 engage~ mandrel 12 a limit switch is activated that in turn activate~ an a~r valve, and a-~sociated cylinder (not shown), advancing compressor arm 25 toward closed clamp K with the separatet segment of L0 shirred casing 15 therebetween. The action of com~ressor arm 25 reestablishes the co~pressed, pleated condition on the short length of deshirred casing on both the fore and aft sections thereof. In U.S. Patent 3,158,896 to Marbach is disclosed the method and operation of compressor arm 25 in compressing ~hirred casing ~egments aga~nst the front wall of clamp K.
In the casing shirring art, the opesation of shirring machines generally, has required that a predetermined length of shirred casing be severed from an advancing supply of tubular casing material before removing from the shirring machine. Consequently the mandrel 12 which defines and forms the bore of the finished casing stick 15, is preferably cantilever supported by clamps C, K, on machine frame lO (Fig. 1). The clamps C, K are alternately opened and closed to permit remo~al of a finished casing stick 15 from mandrel 12, while maintaining the mandrel in alignment with the shirsing means S, as disclosed and described in U.S. Patent 3,158,896 to Marbach.

. . , .

lO~99Zl It is difficult to maintain a deslred, precise al~gnment of the cantilever mounted mandrel 12 to ~hirring means S and to the plane of operation of Qe~ering means 21, 23 spaced from the clamp Jupport C. Thus one embodimen~
of the invention contemplates a plurality of scoring ant/or cutting edgeR arranged in opposed ~elf-centering, blade holder~ 77, 77' atapted to engage and encircle mand~el 12 and thereby score and/or cut deshirred casing 16 substan-tially uniformly at, a plurality of points about the mandrel.
In a preferred embodiment as shown in Fig. 9, an eight point severing blade contact with mar.~rel 12 is provided by casing severing members 21 and 23 opposedly actuated by pneumatic cylinders 76, 78. Each of the severing members 21, 23 has four tubing engaging edges adapted for scoring and/or cutting engagement with mandrel 12 in a self-centeslng action. Thus, in the event of a le~s than perfect initial alignment of the mandrel 12 and severing members 21, 23, such misalignment is self-corrected by the self-aligning severing members.
Refer now to Figs. 9 to 13 wherein is shown the elements of the casing severing members shown generally as 21, 23. Blade holders 77, 77' (Fig. 9) are shown secured to the piston rods of pneumatic cylinders 76, 78 respectively.
Blade holder 77 (Figs. 10, 11) comprises a clevis shaped ~ember atapted to pivotally mount blade mount 80 on blade mount pivot pin 82. Blade mount 80 (Fig. 12) is a slotted member adapted to pivotally mount a pair of severing blades 84, 84' in oppos~te hand (back to back) arrangement by 1~.

, :, ..... . . .. , . . ~ . .. .

10~99 rotatably securing each blade 84, 84' on a single blade pivot pin, 86, 86' re~pectivel~, boeh pins being secured within blade holder 77.
The blade 84 (Fig. 13) is providet with pivot hole 88 and spaced apart bottom and ~ide tubing engaging edges 94, 96, recpectively. When the center of mandrel 12 is used as a central reference point, to define a line "Y" from pivot hole 88 to the centerline of mandrel 12; the edges 94, 96 are each ground at an equal angle fr~m the line '~" ~uch as angle cC
(Fig. 13), for example 45. A l~mit hole 90 which is somewhat larger than blade pivot pin 86 is provided in blade 84 equi-tistant from the centerline of blade 84 to cooperate with mating blade 84 in assembly in mount 80. The difference in diameter be~ween limit hole 90 and pivot pin 86 defines a predetermined limit of pivotal movement permitted for blade 84 about pivot 88. The hole 92 ~n blade 84 is made larger than blade mount pivot pin 82 to permit blade mount 80 to pivot independently of the blades 84, 84' (Fig. 9). Thus the blade assembly described provides two degrees of freedom to pivotally align the blade tubing engaging edges into unifonm gripping contact with mandrel 12 and thereby uniformly ~core and/or cut the casing 16 therebetween.
Activation of severing means 21 and 23 into severing engagement with mandrel 12 accordi~gly, provides for 8 tubing engaging edges contacting the mandrel substantially uniformly about the mandrel. The pivotally mounted blade holders 77, 77- and the p~votally mounted severing blades provide sufficient self-aligning capability to overcome possible misalignment of the mandsel 12 and the tubing engaging edges.

~0499Zl In an alternate embodi~entJ a single severlng blade ~uch a8 blsde 84 h~ving two spaced apart tub~ng engag~ng edges is pivotally mounted in a blade holder or blade mount as described herein. Blade holders may be r~gidly or pivotally ~ecuret to piston rods or the like of at least two air act$vated cylinders mounted unifor~ly ~bout a mandrel. A tubular material may thereby be scored and/or cut at a plurality of points ~ubstantially uniformly about the circumference of the tubing to sever a continuous length thereof into ~egments having substantially "square cut"
ents.
Thus the present invention provides simple, efficient means for automatically severing tubular materials ~heathet about a support mantrel and for continuously and automatically producing from a continuous intefinite length of tubular material, and particularly shirred tubular food casing, segments of such tubular material that may contain pretetermined lengths thereof.
While the invention ha~ been described with partic-ularity and in some detail, it should be understood thatchanges, modifications and alterations can be made therein;
in addition to those suggested and illustrated hereinabove, without teparting from the scope ant spirit of the invention.

16.

Claims (11)

WHAT IS CLAIMED IS:

1. Severing apparatus for flexible, thin-walled tubing material sheathed about a support mandrel comprising at least two severing blades disposed in a substantially uniform circular planar arrangement about a mandrel and adapted to be reciprocated to and from the surface of said mandrel, each of said severing blades being pivotally mounted on a blade holder and having two spaced apart tubing engaging edges, the bisector of the angle subtended by said engaging edges on said blade defining a pivot point for said severing blade, and means for reciprocating said blade holders with said severing blades mounted thereon.

2. The apparatus of claim 1 wherein said blade holders are reciprocated into and out of opposing engagement with said mandrel.

3. The apparatus of claim 1 wherein said tubing engaging edges are cutting edges.

4. The apparatus of claim 1 wherein said tubing engaging edges are scoring edges.

5. The apparatus of claim 1 wherein said blade holder is pivotally mounted to said reciprocating means.

6. The apparatus of claim 1 comprising pivot limit means for said pivotally mounted severing blades.

7. The apparatus of claim 6 wherein said pivotally mounted severing blades include pivot limit means.

8. Severing apparatus for flexible, thin-walled tubing material sheathed about a support mandrel comprising at least two severing means disposed in a substantially uniform circular planar arrangement about a mandrel and adapted to be opposedly reciprocated conjointly to and from the surface of said mandrel, each of said severing means comprising two severing blades pivotally mounted at opposite ends of a blade holder, each of said severing blades having two spaced apart tubing engaging edges that are disposed at an angle to each other permitting both of said edges to engage said mandrel, the bisector of the angle sub-tended by said edges defining a pivot point for said severing blade, and means for reciprocating said sever-ing means.

9. The severing apparatus of claim 8 wherein the blade holder of each of said severing means is pivotally mounted to said reciprocating means at a pivot point that is central to the pivot points for the tubing engaging blades mounted on said holder.

10. The severing apparatus of claim 8 wherein the tubing engaging edges are cutting edges.

11. The apparatus of claim 8 wherein said tubing engaging edges are scoring edges.