Patent GB-1128979-A (GB)
Title: Method and apparatus for making artificial sausage casings
IPC: A22C13/00
Filed: 1965-12-28
Abstract: 1,128,979. Tubular films; extruding sausage casings. W. BECKER. 28 Dec., 1965, No. 54973/65. Headings B5A and B5B. Apparatus for making sausage casings comprises: (a) a supply vessel for coarsely divided fibrous animal skin material; (b) a press including a casing, two platens having opposite, substantially parallel faces in said casing, and actuating means for moving said faces toward and away from each other, whereby a chamber in said casing between said faces is expanded and contracted said chamber being connected to said supply vessel by a supply conduit; (c) feeding means for feeding said material from said supply vessel to said chamber under pressure via said supply conduit; (d) annular shaping nozzle means; and one or more separate discharge conduits connecting said chamber to said nozzle means for discharge of said material from said nozzle means in tubular shape. In Fig. 1 treated animal skin waste, is discharged from bin 1 into slicer 2 and hence via screw feeder 3 to discharge conduit 4 connected to press (see Fig. 2). The press includes a cylindrical upright easing 5a in which a movable platen 9 is mounted on piston rod 9a of hydraulic cylinder 9b. The bottom of casing 5a comprises a fixed platen 10 formed with a central supply aperture 11 and peripheral orifices 12 of discharge conduits 13 which are angularly uniformly distributed about the central supply aperture 11, Fig. 3. Discharge conduits 13 are connected to a common pressure conduit 6, (see Fig. 1) and hence to extrusion device 8. (See Fig. 4). The annular extrusion gap 20 is formed by a tubular stationary outer die 15 and by an inner die 14, provided with a central bore 21 for inflating the extruded tube. Inner die 14 is rotated during extrusion by motor 8<SP>1</SP> not shown. Outer die 15 is coaxially surrounded by a distributor tube 16 of toroidal shape. Circumferentially distributed supply pipes 17 connect tube 16 to conduit 6, and circumferentially distributed radial passages in outer die 15 are connected with distributor tube 16 by short nipples 18 which taper radially inward. Fig. 1 also shows mixing vessel 6<SP>1</SP> and tubular filter housing 7 which are parts of the conduit 6. Pipes 6<SP>11</SP> and 6<SP>111</SP> permit addition agents, e.g. tanning agents or water to be mixed to the material discharged from press 5, and coarse screen material in housing 7 retains contaminants which might damage the extrusion nozzle. Fig. 5 illustrates a modified apparatus having two presses, 5, 5<SP>1</SP> substantially identical with the press 5 of Figs. 1 and 2 and arranged in series and Fig. 7 shows a modified apparatus in which three presses 5, 5<SP>1</SP>, 5<SP>11</SP> are arranged for flow of raw material first through press 5, and then in two parallel streams through presses 5<SP>1</SP>, 5<SP>11</SP>, whose output is jointly fed to mixer 61. Fig. 8 illustrates a modified press incorporating an auxiliary pump. Fixed platen 10<SP>1</SP> and movable platen 9<SP>1</SP> of the press of Fig. 8 are smaller in diameter than the inner wall of casing 5a so that the pressure chamber 22 axially defined between the platens, and the platens themselves, are developed by a pumping space 23 of annular cross-section. Tubular plunger 19 coaxial with platen 9<SP>1</SP> and piston rod 9a is axially slideable in pumping space 23 between the illustrated position in which a portion of the plunger is axially coextensive with the pressure chamber 22 and thereby radially seals the pressure chamber, and a non-illustrated position in which plunger 9<SP>1</SP> is lifted so as to permit flow between pressure chamber 22 and discharge conduits 13 whose orifices are located at the bottom of pumping space 23. The press is fitted with a hydraulic cylinder 9c having a central cylindrical chamber and a peripheral chamber of annular section. The two chambers accommodate respective conforming pistons in a manner not shown in Fig. 8 connected to platen 9 and plunger 19 by respective pistons rods 9a and 24. The control valves of cylinder 9c (not shown) are so arranged that platen 9<SP>1</SP> moves upwards when plunger 19 moves downwards and vice versa. Platen 9<SP>1</SP> draws material into pressure chamber 22 while previously disintegrated material is discharged through discharge conduits 13 by plunger 19. While material is being transferred from chamber 22 to space 23 by the descending platen 9<SP>1</SP>, and is disintegrated in the process, plunger 19 is lifted to open the pumping space 23. The several presses shown may be provided with platens 9<SP>11</SP>, 10<SP>11</SP> whose opposite faces have circular corrugations 25 which are saw-toothed shaped when viewed in axial section, as in Fig. 6. The corrugations of lower platen 10<SP>11</SP> have a gentle slope toward the central aperture 11<SP>1</SP>, and slope more steeply toward the periphery. Such corrugations tend to retain larger fibre aggregates, such as knots of grain material, in the pressure chamber of the press until they are disintegrated. Disintegration of the material is enhanced by series arrangement of several presses as shown in Figs. 5 and 7, especially if the minimum gap between the platens decreases in successive presses. A more rapid decrease in gap width without undue pressure drop is possible when two presses are arranged in parallel behind a preceding press, as in Fig. 7. In place of hydraulic cylinders, the presses may be actuated by other known means.