GB1598706A

GB1598706A - Apparatus suitable for bellows-like shirring of a tubular casing

Info

Publication number: GB1598706A
Application number: GB5404077A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-12-28
Filing date: 1977-12-28
Publication date: 1981-09-23

Description

(54) APPARATUS SUITABLE FOR BELLOWS-LIKE SHIRRING OF A TUBULAR CASING (71) I, GIANTER KOLLROSS, a German citizen of Wallerstädter Weg 20, 6081 Dornheim, Bundesrepublik, Germany, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to apparatus suitable for bellows4ike shirring of a tubular casing for e.g. a sausage.

During shirring of a synthetic tubular casing for sausages, there exists the special problem of laying the casing in folds running transversely over its length (which remains constant in cross-section) in such a manner that, subject to maintenance of a specific clear width in the interior of the shirred casing, air pockets between the folds are avoided to the greatest extent. It is desirable, in order to obtain maximum compaction, that the folds formed by the shirring be made stable in order to prevent independent disintegration during further processing. The casing to be shirred is distinguished from a concertina, whose width along its axis changes constantly whereby the number and position of the folds are originally prescribed.

In order to combat the manufacturing problems which exist, various methods and devices have already been proposed. All of these methods and devices have in common the use of a mandrel for passing through the casing, the mandrel having a relatively narrow circular cross-section, which is usually formed from a taper bore mounted mandrel. The casing is pushed together in an axial direction on the mandrel by means of shirring elements applied at the circumference of the casing and which transport the casing axially, against a controlled yielding buffer, to effect the formation of folds.

In order to achieve a certain orderliness in the formation of folds, it has been proposed that a torsional or rotary movement be carried out between the mandrel and the shirring elements. The shirring elements are principally in the form of sectioned rollers, which are engaged on the casing so as to form folds. By means of this measure, a certain orderliness is introduced to the fold formation. But fold formation is not possible of a type which ensures full exploitation of the radial distance available between the mandrel and the full width of the casing by circumferentially staggering the axially following folds, the circumferential extension of each of them being limited.

A known method prefers that the casing is pushed forward on the mandrel between three evenly-cogged shirring rollers, the cogs of which are formed in the same manner as those of a worm wheel. In this case, the crests of the teeth meeting simultaneously on the mandrel form themselves into an eccentric opening, which moves further from tooth to tooth by 1200 in the circumferential direction, and thereby leads to a fold formation with a spiralled outer circumference which is larger than the circumference of the unshirred casing. Since the volume available for shirring is increased a particularly great amount, a great length of casing material can be shirred by comparison to other methods. However, the casing is subjected to considerable stress between the toothed rollers, which is undesirable due to the danger of damage.Apart from this, this known method requires an exchange of shirring rollers upon change over to other casing cross-sections (which should preferably be avoided) so as to keep the shutdown times at a minimum.

According to a first aspect of the present invention there is provided apparatus suitable for;bellows-like shirring of a tubular casing, the apparatus comprising a fixture; a mandrel arranged in said fixture and in an overhung position for receiving a said casing when fed over its free end; buffer means arranged on said mandrel and forming a stop for said casing, said buffer means being withdrawn in a controlled manner during the shirring operation; and a shirring head comprising at least three shirring rollers each having on its periphery a circumferential groove of a cross section defining a circular figure, said rollers being arranged around said mandrel and in a circumferentially spaced relationship relative to each other such that said grooves define a circular passageway for said mandrel, said passageway being of greater diameter than said mandrel, the centre of said passageway being eccentrically spaced relative to the axis of said mandrel, said rollers being movable as a whole in such a manner that said eccentrically spaced centre of said passageway moves on a circle around said axis of said mandrel, said rollers being rotatable around axes positioned in a plane perpendicular to the axis of said mandrel.

According to a second aspect of the present invention, there is provided a method for bellows-like shirring of a tubular casing, comprising carrying out said shirring with apparatus according to said first aspect of the present invention.

The present invention is particularly suitable for use in shirring a synthetic tubular casing for a sausage but could be used e.g.

for a natural casing for a sausage.

An example of the invention as applied to sausage casings will now be described with reference to the accompanying drawings, in which: Fig. 1 is a schematic side elevational view of one example of shirring apparatus constructed in accordance with the invention; Fig. 2 is an enlarged rear elevational view of the front section of a shirring head in the direction of arrow A in Fig. 1: and Fig. 3 is a view of a roller assembly, partially in section, taken along the lines III- III in Fig. 2.

Referring to the drawings, the invention exemplified therein, comprises a device for the shirring of sausage casings (e.g. a synthetic casing) which includes a guide mandrel or hollow tube 32 over which the casing is positioned before it is moved into association with a shirring head 20.

The shirring apparatus shown in Fig. 1 includes a frame 10 with a partially hollowed-out bench 12, upon which a squeeze roller unit 14, a pressing unit 16, a conveyor device 18, the shirring head 20 and a pair of guide rods 22 (only one rod is visible), are arranged in order. A revolving head unit 26 is longitudinally slidable on the guide rods 22 by means of a power cylinder 24. The revolving head unit 26 includes a revolving disc 28 which carries four detachable guide elements or tube-shaped mandrels 32, each fitted with buffer discs 30. In the retracted position of the revolving head unit 26 shown. the mandrels 32 are withdrawn from the shirring head 20.Mandrels 32 can be switched into a forward position by the power cylinder 24 in which position they extend through the shirring head 20 and through the conveyor device 18, which serves as the initial position for the shirring of a casing length.

The casing (e.g. a synthetic casing) to be shirred is fed along an axis 36 from a storage reel (not shown) at the left end of the frame 10 through the squeeze roller unit 14 and the pressing unit 16 onto a respective mandrel 32 and is supplied by conveyor unit 18 to the shirring head 20. Head 20 lays the casing in folds, in the manner described below, and shirrs this together in the shape of a bellows on the mandrel 32 against the buffer 30 which mandrel is retracted together with the revolving head unit 26 in a controlled manner.Squeeze rollers 14a and 14b in unit 14, the conveyor rollers 18a and l8b in unit 18, and the rollers 88 (see later below) of the shirring head 20 are driven by V-belt drives by a DC motor 38 located in the lower part of frame 10, which motor is coupled to the drive shaft by means of a geared magnetic coupling, and its speed is regulatable, Further, air is blown through each mandrel 32 when it is in an operating position for inflation of the casing in the pressing section 16 and the conveyor section 18 and, in particular, in the shirring head 20, to the squeezer rollers 14, which effects sealing.

The design of the shirring head 20 and its bearings on the frame 10 can be seen in detail in Figs. 2 and 3. As these figures indicate, two pairs of pillow blocks 40 and 42 are fixed on the bench 12, in each one of which a respective eccentric shaft 48 is supported on ball bearings 44 and 46 respectively. The two eccentric shafts 48, 48 are coupled with each other in synchronized operation through a toothed belt drive 50 and are driven by a DC motor 52 arranged in the lower part of the frame 10, regulatable and fitted with magnetic coupling over a further toothed belt drive 54.

Each eccentric shaft 48 has a cylindrical portion 56 of enlarged diameter on which an eccentric bush 60 is unrotatably arranged.

The bush 60 has a flange 58 on one end thereof and a thread on its other end. An eccentric sleeve 64 having a flange 62 on one end thereof is turnably arranged on bush 60, flange 62 being adjacent flange 58. The sleeve 64 can be unturnably fixed on bush 60, by a nut 66 and a lock-nut 68 providing adjustment of the total eccentricity of the periphery of sleeve 64 in relation to shaft 48.

The eccentricities of bush 60 and sleeve 64 are of the same size, thereby allowing adjustment of the total eccentricity between zero and the double value of the eccentricity of the bush or sleeve, respectively.

A flanged hub 74 having a flange 76 on one end thereof is rotatably supported by ball bearings 70 and 72 respectively on eccentric sleeve 64 and the flange 76. The flange 76 is screwed to a base plate 80.

Base plate 80 is a star-shaped assembly having three pairs of parallel flanges 82 and 84 spaced to provide slits between each pair of flanges, said slits meeting in the centre of the star. In each slit, a fork shaped pillow block 86 for a respective shirring roller 88 is displaceable radially in respect to the star centre and adjustable by means of a thread setting device 90. The shirring rollers 88 are firmly arranged on extended shafts 92, which are drivingly connected to each other by pairs of bevelled gears 94 and 96. The upper shaft 92a carries two bevelled gears 96, which are driven through an extendible intermediate shaft 98, and universal joints 100 arranged on both sides of the shaft by the regulated DC motor 38. In Fig. 2, only the shaft 92a is shown.

The shirring rollers 88 are driven with a peripheral speed substantially higher than the speed of retraction of the buffer 30. The rollers 88 are of a flexible material, for instance expanded isocyanate polyester, and are preferably toothed or knurled at their circumference in order to ensure a better gripping of the casing to be shirred and to ensure fold formation between the teeth.

Depending on the set eccentricity of the outside area of eccentric sleeve 64, the shirring rollers 88 of the shirring head 20 engage with the cyclic profile 102 (Fig. 2) which corresponds with the outside circumference of the inflated casing to be shirred. The profile 102 is defined by the circumferential grooves of three shirring rollers 88. The profile 102 is eccentric to the mandrel 32 (not shown in Fig. 2), which has a smaller diameter than profile 102. During shirring, the centre of profile 102 rotates around the axis of mandrel 32.The resultant eccentric movement can amount to 800 to 1,000 rpm, and is chosen in such a way that in connection with the simultaneous pushing forward of the casing by the rollers 88, a spiralled continuous fold formation of the casing is formed on the mandrel 32 and, at the same time, pressure against the buffer disc 20 or the material in front of that which is already shirred, takes place.

The shirring apparatus can be automated in such a way that after the shirred casing has reached a certain length, the magnetic coupling of the motors 38 and 52 can be released by means of a contact activated by the returning revolving head unit 26, whereupon, the revolving head unit 26 retracts completely and switches further. By means of renewed forward drive of the revolving head, a new mandrel 32 is led into the cut casing end, and the magnetic couplings of the motors 38 and 52 are re-engaged after the front end position of the revolving head unit is reached, whereupon, a new shirring cycle begins.

WHAT I CLAIM IS: 1. Apparatus suitable for bellows-like shirring of a tubular casing, the apparatus comprising a fixture; a mandrel arranged on said fixture and in an overhung position for receiving a said casing when fed over its free end; buffer means arranged on said mandrel and forming a stop for said casing, said buffer means being withdrawn in a controlled manner during the shirring operation; and a shirring head comprising at least three shirring rollers each having on its periphery a circumferential groove of a cross section defining a circular figure, said rollers being arranged around said mandrel and in a circumferentially spaced relationship relative to each other such that said grooves define a circular passageway for said mandrel, said passageway being of greater diameter than said mandrel, the centre of said passageway being eccentrically spaced relative to the axis of said mandrel, said rollers being movable as a whole in such a manner that said eccentrically spaced centre of said passageway moves on a circle around said axis of said mandrel, said rollers being rotatable around axes positioned in a plane perpendicular to the axis of said mandrel.

2. Apparatus as claimed in Claim 1, in which said shirring head is supported on said fixture by two rotating shafts parallel to each other, said shafts having eccentric portions on which said shirring head is pivoted.

3. Apparatus as claimed in Claim 1 or 2, in which said rollers have toothed peripheries.

4. Apparatus as claimed in Claim 3, comprising means to drive said rollers at a higher peripheral speed than the speed by which the buffer means is withdrawn during shirring operation.

5. Apparatus as claimed in Claim 2 or any claim dependent thereon, comprising a separate variable speed drive motor connected to said shafts for rotating said shafts.

6. Apparatus as claimed in Claim 2 or any claim dependent thereon, comprising means for rotating said shafts, independably from said rollers, this means comprising a control D C motor.

7. Apparatus as claimed in Claim 2 or any claim dependent thereon, in which said eccentric portions comprise adjustable eccentrics.

8. Apparatus as claimed in Claim 7, in which said adjustable eccentrics each comprise an eccentric bush unrotatably arranged over its shaft, and an eccentric sleeve positioned over said bush, said sleeve being circumferentially adjustable on said bush so as to provide adjustable eccentricity of the periphery of said sleeve in relation to said shaft.

9. Apparatus as claimed in any one of the preceding claims, in which said rollers

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Claims

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84 spaced to provide slits between each pair of flanges, said slits meeting in the centre of the star. In each slit, a fork shaped pillow block 86 for a respective shirring roller 88 is displaceable radially in respect to the star centre and adjustable by means of a thread setting device 90. The shirring rollers 88 are firmly arranged on extended shafts 92, which are drivingly connected to each other by pairs of bevelled gears 94 and 96. The upper shaft 92a carries two bevelled gears 96, which are driven through an extendible intermediate shaft 98, and universal joints 100 arranged on both sides of the shaft by the regulated DC motor 38. In Fig. 2, only the shaft 92a is shown.

The shirring rollers 88 are driven with a peripheral speed substantially higher than the speed of retraction of the buffer 30. The rollers 88 are of a flexible material, for instance expanded isocyanate polyester, and are preferably toothed or knurled at their circumference in order to ensure a better gripping of the casing to be shirred and to ensure fold formation between the teeth.

Depending on the set eccentricity of the outside area of eccentric sleeve 64, the shirring rollers 88 of the shirring head 20 engage with the cyclic profile 102 (Fig. 2) which corresponds with the outside circumference of the inflated casing to be shirred. The profile 102 is defined by the circumferential grooves of three shirring rollers 88. The profile 102 is eccentric to the mandrel 32 (not shown in Fig. 2), which has a smaller diameter than profile 102. During shirring, the centre of profile 102 rotates around the axis of mandrel 32.The resultant eccentric movement can amount to 800 to 1,000 rpm, and is chosen in such a way that in connection with the simultaneous pushing forward of the casing by the rollers 88, a spiralled continuous fold formation of the casing is formed on the mandrel 32 and, at the same time, pressure against the buffer disc 20 or the material in front of that which is already shirred, takes place.

The shirring apparatus can be automated in such a way that after the shirred casing has reached a certain length, the magnetic coupling of the motors 38 and 52 can be released by means of a contact activated by the returning revolving head unit 26, whereupon, the revolving head unit 26 retracts completely and switches further. By means of renewed forward drive of the revolving head, a new mandrel 32 is led into the cut casing end, and the magnetic couplings of the motors 38 and 52 are re-engaged after the front end position of the revolving head unit is reached, whereupon, a new shirring cycle begins.

WHAT I CLAIM IS: 1. Apparatus suitable for bellows-like shirring of a tubular casing, the apparatus comprising a fixture; a mandrel arranged on said fixture and in an overhung position for receiving a said casing when fed over its free end; buffer means arranged on said mandrel and forming a stop for said casing, said buffer means being withdrawn in a controlled manner during the shirring operation; and a shirring head comprising at least three shirring rollers each having on its periphery a circumferential groove of a cross section defining a circular figure, said rollers being arranged around said mandrel and in a circumferentially spaced relationship relative to each other such that said grooves define a circular passageway for said mandrel, said passageway being of greater diameter than said mandrel, the centre of said passageway being eccentrically spaced relative to the axis of said mandrel, said rollers being movable as a whole in such a manner that said eccentrically spaced centre of said passageway moves on a circle around said axis of said mandrel, said rollers being rotatable around axes positioned in a plane perpendicular to the axis of said mandrel.
2. Apparatus as claimed in Claim 1, in which said shirring head is supported on said fixture by two rotating shafts parallel to each other, said shafts having eccentric portions on which said shirring head is pivoted.
3. Apparatus as claimed in Claim 1 or 2, in which said rollers have toothed peripheries.
4. Apparatus as claimed in Claim 3, comprising means to drive said rollers at a higher peripheral speed than the speed by which the buffer means is withdrawn during shirring operation.
5. Apparatus as claimed in Claim 2 or any claim dependent thereon, comprising a separate variable speed drive motor connected to said shafts for rotating said shafts.
6. Apparatus as claimed in Claim 2 or any claim dependent thereon, comprising means for rotating said shafts, independably from said rollers, this means comprising a control D C motor.
7. Apparatus as claimed in Claim 2 or any claim dependent thereon, in which said eccentric portions comprise adjustable eccentrics.
8. Apparatus as claimed in Claim 7, in which said adjustable eccentrics each comprise an eccentric bush unrotatably arranged over its shaft, and an eccentric sleeve positioned over said bush, said sleeve being circumferentially adjustable on said bush so as to provide adjustable eccentricity of the periphery of said sleeve in relation to said shaft.
9. Apparatus as claimed in any one of the preceding claims, in which said rollers

are comprised of a foamed isocyanate-polyester material.
10. Apparatus as claimed in any one of the preceding claims, in which said rollers have toothed formations around their peripheries.
11. Apparatus as claimed in Claim 1, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
12. A method for bellows-like shirring of a tubular casing, comprising carrying out said shirring with apparatus according to any one of Claims 1 to 11.
13. A method as claimed in Claim 12, in which said casing is a casing for a sausage.
14. A method as claimed in Claim 13, in which said casing is a synthetic casing for a sausage.
15. A method as claimed in Claim 12, in which said method is carried out substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
16. A tubular casing which has been shirred by a method as claimed in any one of Claims 12 to 15.