FR2481226A1 - APPARATUS AND METHOD FOR CONTINUOUS JAMMING OF SOFT ARTICLES IN DISCONTINUOUS LENGTHS OF FLEXIBLE TUBULAR ENVELOPE, ESPECIALLY HAMS AND OTHER PIECES OF WHOLE MEAT - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS AND AN APPARATUS FOR STUFFING A WHOLE HAM WITHOUT BONE IN AN ENVELOPE LENGTH. THE HAM 32, AFTER HAVING BEEN PLACED IN A LOADING CHAMBER 34, IS PUSHED INTO A CENTRAL SUPPORT TUBE 30 THROUGH WHICH IT CAN BE INTRODUCED IN A LENGTH OF ENVELOPE 60 WHICH IS DEPLISSE IN THE FUR AND TO THE MEASURE OF THE JAM, IN SAME TIME THAT THE AIR IS CONTINUOUSLY VENTILATED FROM THE INSIDE OF THIS LENGTH OF ENVELOPE 60. THIS LATTER, ONCE STAMPED, IS CLOSED BY MEANS OF A TIE AND SECTIONED. FIELD OF APPLICATION: PACKAGING OF HAMS AND OTHER WHOLE PIECES OF MEAT.

Description

The invention relates to the conditioning of meat, and more

  particularly stuffing whole pieces of boneless meat into envelopes to form separately packaged meat items. The invention relates more particularly to the packaging of whole hams without bone in unfolded lengths of shell,

  from a continuous pleated envelope.

  Techniques for jamming viscous meat emulsions in flexible, continuous food casings are now well known in the meat and processed meat packaging industries. The most recent developments in this field of technology relate to the use of long pleated lengths of flexible tubular casing for food products, stuffed onto a high speed automatic stuffing machine to produce large sausages such as mortadellae, liver sausages and the like, as described in detail, for example, in U.S. Patents No. 4,017,941 and

No. 4,044,426.

  In another field of the meat packaging industry, having a certain technological relationship with the previous one, whole pieces of boneless meat such as hams are wrapped in flexible tubular envelope lengths for foodstuffs and ligated to the ends to form

  individually packaged and separated food items.

  These packaging techniques usually include slow operations and require significant work. In practice, a whole piece of boneless meat, usually a ham, is introduced by hand and freely in a cut length of previously impregnated envelope and which has been previously ligated or closed by a fastener at one end. The introduction of the ham into the envelope is done manually or is assisted by means of any meat press, commercially available. During a subsequent pressure-packed operation, the ham is packed tightly in the envelope at the same time as the air retained in the envelope is expelled and that ham is shaped. The operator can also "glue" the envelope during the pressure packing operation by making holes that facilitate the expulsion of air from inside the stuffed envelope. The open end of the stuffed envelope is then ligated or closed by a fastener to complete the packaged food item. Typical techniques for pressure-packed boneless meat cuts are described in U.S. Patent Nos. 3,115,733 and 3,065,585. Increased Automation of Whole Piece Stuffing Technology Bone-free is described in U.S. Patent No. 3,919,739. In the latter patent, a continuous web envelope imbibition device is used in association with a carriage to continuously position the open end. an envelope in alignment with a nozzle of a stuffing element. The envelope being impregnated and thus placed in place, a piece of meat is introduced freely into the envelope length momentarily held. After the first attachment is made, the unattached end of the stuffed envelope is drawn tightly around the piece of meat to conform to its shape and also to retain the air inside the piece stuffed envelope is expelled. The unattached end of the wrapper is then ligated or closed by a fastener, and the wrapped meat article thus obtained is cut and

  separated from the continuous length of feed casing.

  Although the apparatus described in US Pat. No. 3,919,739 represents a progress towards the automatic jamming of hams that is desired, it is not a very satisfactory technique. A major drawback lies in the fact that the stuffing envelope advances in the opposite direction to that of the progression of stuffing articles. Each stuffing action constitutes a kind of frontal collision between the ham and the length of envelope in which it must be placed. Since, because of the design of the apparatus, it is impossible to continuously fill the envelope strip

  continued by one-way actions corresponding to

  In the sense of progress of the hams being treated, these movements in the opposite direction of the wrapper band and the hams are, by their nature, ineffective from a mechanical point of view. Another characteristic of the technique described in the aforementioned patent No. 3,919,739, which is detrimental to the effectiveness of the packaging, is that the hams are introduced into a casing which freely surrounds them and which is then pressed onto these hams for in

  marry the shape and expel the air from the packaged item.

  These lack of efficiency and other defects are eliminated

  by the invention as described in more detail below.

  The invention is conceived and developed from

  the state of the art described above.

  The invention thus relates to a method and apparatus for introducing a whole piece of meat without bone, for example a ham, into a pre-attached ends of a casing length previously folded and mounted, under continuous pressure. , while permitting a continuous escape of the air which tends to be retained during the process of insertion or stuffing, the method and apparatus according to the invention also making it possible to tighten and to fasten the open end of the envelope stuffed while holding the product wrapped under a certain pressure, the unfolded end of a length of previously folded envelope, which immediately follows, being constricted and attached, the stuffed and finished product being separated from the envelope which follows and the cycle described above being repeated after setting up another piece of

meat in the device.

  The basic concept and development of the invention involves the adaptation and application of some of the principles and parameters for making large sausage casings using automatic equipment, as described in US Pat. No. 4,017,941 and 4,044,426, automatic tamping of boneless whole hams or other pieces of meat in lengths of casing to produce tightly wrapped and stuffed food items and

separated from each other.

  The object of the invention is an automatic and rapid method and apparatus for pressure-packed boneless whole ham or other similar pieces of meat in flexible, large tubular casings. The invention makes it possible to control frankly and regularly reproducible products formed continuously, requiring a minimum of human intervention and handling of the food product, and using an efficient and relatively uncomplicated apparatus. An advantageous feature of the invention is its ability to use pleated and compressed envelope lengths such as those described in US Pat. No. 4,007,761, which do not require prebuffing prior to stuffing. Another feature of the invention is its ability to control the

  dimension of the finished product if desired.

  Other advantageous features of the invention lie in its ability to stuff a product by virtually eliminating the entrained air, and to consistently produce stuffed products having a suitable outer layer of fat and good orientation of the flesh. . The invention further allows the meat to be maintained under constant pressure during tamping and fastening, thereby avoiding the need for an independent pressurizing or compression stuffing operation to remove air and in

form the meat.

  In addition, an important feature of the invention is that it allows significantly increased production rates by requiring operators to work less. The invention thus generally relates to an apparatus for continuously filling whole pieces of boneless meat or other soft articles in staple lengths of flexible tubular casing, said apparatus comprising a frame, a set with a stuffing mandrel mounted on the frame, a central support tube of this assembly, arranged coaxially inside the latter and having a discharge end and a flared inlet end, a loading chamber of an article which communicates with the flared end of the central support inlet tube, a closure device placed on the loading chamber and movable between open and closed positions to allow lateral access to the loading chamber of a article when in the open position, a locking device securing the closure device in the closed position, a compression bar extending longitudinally to the loading chamber of the article and movable between a retracted position and an extended position, which bar has a configured face which defines a wall portion of the loading chamber of an article when the bar - is in the extended position, an actuating device operably connected to the compression bar so as to be able to selectively move it between its retracted and extended positions, a first piston element placed in longitudinal axial alignment with the central tube of supporting the stuffing mandrel assembly and having a face intended to come into contact with an article, said piston member being movable between a first position in which the contact face is disposed at the rear end of the loading chamber; of an article and a second position in which the contact face is disposed in the flared inlet end of the central support tube, a second piston element arranged coaxially in the first piston element and having a surface intended to come into contact with an article and capable of reciprocating between a first position in which the contact face is disposed in the flared inlet end of the central support tube and a second position in which the contact face is disposed at the discharge end of the central support tube of the stuffing mandrel assembly, a device for holding a pleated envelope disposed coaxially around of the stuffing mandrel assembly and mounted to deliver a continuous and unfolded casing to be stuffed onto the discharge end of the central support tube of the stuffing mandrel assembly, in the direction of advancement of the pieces of meat to be wrapped, an attachment device and a severing device for attaching the separate lengths of the envelope and cutting between the attached portions to form individual lengths of product, and a motor device for controlling the reciprocating movements of the first and second

piston elements.

  The central support tube of the stuffing mandrel assembly is used, between its inlet and outlet ends, as a conduit carrying the boneless whole ham of the meat loading chamber, connected to the flared end of entrance, up to an envelope that is unfolded from a mounted feed stick,

  consisting of a folded envelope and arranged concentrically

  above all. The meat loading chamber has a first end which communicates with the flared end of the central support tube, a door comprising a device for closing, locking and reopening it automatically, and a device for compressing laterally a mass of meat placed inside the chamber. The second end or rear end of the meat loading chamber is connected to a longitudinal stuffing device of the product comprising

first and second pistons.

  The longitudinal product tamping device comprises a stepped piston designed to be advanced and longitudinally reclined, in axial alignment with the meat loading chamber and the central support tube. The first stage of the piston is adapted to move in the meat loading chamber to the flared inlet end of the central support tube to thereby advance a mass of meat from the loading chamber into the tube. central support. The second stage of the piston moves concentrically in the first stage, through the central support tube, to the discharge end of the latter, to further advance the mass of meat to introduce it completely into a unfolded length of the food item previously packaged in the envelope. The movements of the second piston begin

  after the end of the movement of the first piston.

  A support sleeve can turn advantageously

  on the central support tube and can carry a device for the removable mounting and fixing of a calibration disk which is implanted in a previously folded tubular casing for food products used in the packaging process. In the embodiments shown in the accompanying drawings and described hereinafter, the calibration element or disk is designed to allow the exhaust air to escape from the central support tube during the stuffing operation. This disc also allows the continuous escape of any air that may have been entrained inside the packaged food product during the progress of the stuffing. The air passes from the front end of the envelope section being jammed to the discharge end of the central support tube of the stuffing mandrel assembly in the space between the inner surface of the and outer surface of the central support tube of the stuffing mandrel assembly and openings in the calibration disc. It is extremely important to emphasize, at this stage of the

  description, the need to allow the escape of air

  which is otherwise retained in the wrapped food product during the stuffing operation. For this purpose, various variants of air ventilation means may be used. In the embodiment of the apparatus according to the invention shown in the accompanying drawings, vents are provided in the calibration disc. In other embodiments of the apparatus according to the invention, for example those which may not use a calibration disc, but now the envelope by the application of an external peripheral force, around the envelope, producing a retaining action, the presence of vents may take the form of a free fit of the sleeve between the central support tube and a support sleeve, or of a free fit between the central support tube or the sleeve support and a sleeve holding the pleated envelope in position. The ventilation of the air towards the rear of the stuffing point can also be ensured by the presence of longitudinal grooves formed in the surface of the central support tube or any equivalent structure that can be used in a given apparatus. Air can

  thus flow backwards through the longitudinal grooves

  dinals or notches in order to be expelled by the open end of the light from the envelope. Other forms of air ventilation means will inevitably appear in

  those skilled in the art on reading the following description. he

  suffice to indicate that it is necessary to provide ventilation of the air to ensure the elimination of air that might otherwise be retained in the finished product, this elimination being obtainable by any of the structures described

  previously or by their combinations or equivalents.

  The pre-packaged food item wrapped and obtained with the apparatus according to the invention, comprising an air calibration / ventilation device and a pre-folded tubular casing for food products, is preferably similar to that described in detail. in the above-mentioned patent NI 40027761. The support sleeve is adapted to be reciprocated to move the fixed air calibration / ventilation device between predetermined positions in advance and

  supports the pleated tubular casing.

  The apparatus also includes a retaining device comprising a retaining carriage for axial alignment with the central support tube of the stuffing mandrel assembly and carrying a retaining ring to be advanced over this assembly and to be removed. The retainer cooperates with the air calibrator / vent to determine the size (diameter) of the product, as described in US Patent No. 4,164,057. also a conventional fastener closure device and a cutting device. In its retracted position, in which it is spaced from the stuffing mandrel assembly, the holding carriage is also adapted to be moved transversely toward the axis of the central support tube and in the opposite direction in order to

  allow the loading and fixing of the article

  packaged with a pleated envelope on the support sleeve. A motor device controls the support sleeve and the retainer to adjust the position of the support sleeve relative to the central support tube and the position

  of the support sleeve relative to the retainer.

  Pneumatic actuating and controlling devices are used to operate the support sleeve, the meat-loading chamber locking device, the lateral compression device, the longitudinal product stuffing device and other elements. of the retainer carriage, in a combined manner, for selectively controlling continuous cycles of successive compression, tamping, fastening, and cutting operations and thereby forming a product consisting of a bone-free whole ham stuffed, compressed and surrounded by a flexible tubular envelope closed by attachments0 It should be emphasized that, although the forms

  described methods use

  completely pneumatic control system, it is possible to use in a completely satisfactory manner variants of these actuating devices and

  hydraulic or electropneumatic control.

  The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting example and

on which ones -

  FIG. 1 is an elevation with partial section of the apparatus according to the invention, this view showing a whole ham with bone in position in the loading chamber of the apparatus. FIG. 2 is a partial view from above of FIG. the apparatus of Figure 1, showing how the piece of meat to be stuffed is initially placed under compression; - Figure 3 is a section along the line 3-3 of Figure 2, showing the end of the loading chamber and the device to compress the meat; FIG. 4 is a partial sectional elevation of the apparatus of FIG. 1, showing the lid of the loading chamber in the closed position and the lateral compression completed; - Figure 5 is a section along the line 5-5 of Figure 4, showing the end piece of meat in the chamber, in the compressed state; Figure 6 is an elevation, partly in section, of the apparatus of Figure 1 showing the piece of meat pushed inside and partially through the stuffing mandrel by the first plunger; Fig. 7 is an elevation, partly in section, showing the piece of meat pushed completely through the stuffing mandrel and inside the casing by the second plunger; - Figure 8 is an elevation, in partial section, of the apparatus of Figure 1, showing the piece of meat completely wrapped, the envelope being cut, the pistons being fully retracted and the loading chamber being open; and FIG. 9 is a partial perspective view of the loading chamber, showing the guides

  or orientation ribs of the product.

  FIG. 1 shows the apparatus according to the invention

  which comprises a frame 16 on which is mounted a

  set 18 with stuffing mandrel. This set includes

  even a central support tube 30 disposed coaxially within the stuffing mandrel assembly and having a discharge end 29 and a flared end 31 at the inlet. A chamber 34 for loading an article is located behind the flared end 31 of the inlet of the central support tube 30 and communicates with this end. The loading chamber 34 comprises a door or any other element 42 closing that rises pivoting or sliding to allow access to this room. When the closing element 42 of the loading chamber 34 is in the fully open position, the chamber appears as shown in FIG. 2, that is to say in the position of maximum volume available for loading the chamber. item to be packaged. Figure 3 shows the end device in this position. Cylinders or elements 48 for locking the door of the loading chamber are provided for fixing the closure element 42 in the closed position. A bar 36 for compressing an article is arranged longitudinally on the

  loading chamber 34 and has a configured face 35.

  The compression bar 36 is animated. reciprocating by side cylinders 50 shown in the retracted position in FIGS. 2 and 3. When these actuating cylinders are actuated, the compression bar 36 is advanced towards the position shown in FIG. 5 in which the face configured 35 forms a part of a wall of the chamber 34 loading. A multi-piston control device comprises a first piston 54 and a second piston 58 aligned with the article loading chamber 34 and the central support tube 30 of the stuffing mandrel assembly 18. In the embodiment shown, the second piston 58 is coaxially disposed in a cylinder formed in the first piston 54 so that the two elements initially constitute a single piston. The use of these pistons may be on one side of the second piston, as shown in the figures or, alternatively, the pistons may have separate faces intended to come into contact with the article, one of these faces having an annular shape and being constituted, in fact, by the edge or the extreme rim of the first piston 54, and the other face having a circular shape and being constituted by the face of the second piston 58. In all cases, it the pistons are designed to operate in two phases, namely a thrust phase of the mass of

  meat or any other soft material compressed side-

  in order to advance it into the loading chamber when the latter is in the closed position and to introduce it into the flared end of the central support tube, and a second phase during which the mass of meat has passed. completely in the central support tube, to the discharge end of the latter o the meat is brought into contact with the front edge, closed by url attachment, the envelope being filled. To avoid the possibility of retaining certain parts of the meat between the end of the first piston 54 and the flared end 31 of the inlet of the central support tube 30, the face of the second piston 58 must never be able to exceed the edge or extreme edge of the first piston 54 before completion

  complete tamping movement of this first piston 54.

  The embodiment shown in the figures is provided for mounting by the front end of a stick 22 consisting of a pleated casing and arranged coaxially on the sleeve 24 of support of the assembly 18 to stuffing mandrel. The movement of the envelope thus mounted is controlled by means of a calibration disk 26 mounted in a retaining recess in the support sleeve 24 and the maintenance of the advance pressure of the envelope is also controlled as and as the envelope is unfolded by means of a cylinder 68 giving slack to the envelope. The criteria and characteristics of use of the stick 22 formed by the envelope during its unfolding thus controlled, are similar to those indicated in the aforementioned patent No. 4,044,426. A retainer carriage 20 is disposed at the front end or discharge end of the apparatus and includes fastener means 70 and 74 and a cutter 76 for attaching staple casing lengths to the casings. closing, and cutting the envelope between the attached sections to form separate lengths of product 78. A pneumatic cylinder 56 with automatic control is arranged so that one of its ends is fixed and connected by a movable end to a stirrup performing to the stepped piston

54, 58 his cycles of movement.

  In a particular case, it is conceivable that it is desirable to operate the apparatus according to the invention without carrying out the fastening and cutting operations, that is to say by performing these functions in a manner.

  another point in the production chain.

  Figure 9 is a perspective view of the article loading chamber shown in the open position and the piston member is shown in the free position. The lateral compression bar 36 and its control cylinders 50 are shown in the retracted position. This embodiment of the invention utilizes ribs 82 located longitudinally on the walls of the loading chamber. One of the ribs 82 is part of the compression side bar, as shown, and the other two ribs are located on the curved wall of the fixed portion of the loading chamber. These ribs have the function, when they are used in one embodiment of the apparatus according to the invention, of constituting orientation projections or a strip intended to guide the ham during packing in a correct manner. , linear and precise. In practice, it has appeared that the presence of these ribs in the apparatus eliminates the problems posed by the bad orientation of the flesh and the fat and by the unpleasant twisting of the ham during its stuffing in

  the stuffing mandrel assembly and the envelope.

  The retainer carriage 20 is moved to the transverse loading position. A food article 22, pre-packed in a pleated envelope, is placed on the support sleeve 24, the attachment being made by means of the fingers of the calibration disc 26. The carriage deretenue 20 is then moved transversely so that the central axis of the retaining ring 28 is aligned with the central axis of the

central support tube 30.

  With the apparatus returned to the starting position (FIG. 1), a whole ham 32 without bone is placed in the chamber 34 for loading the meat. As shown in Figures 2 and 3, the initial position of the compression side bar 36 provides a suitable side space and the depth of the meat loading chamber (about 12.5 cm while the diameter of the central support tube is about 9 cm or less) suitably allows the meat mass to be arranged conveniently and properly prior to stuffing. In other words, the flesh 38 of the ham is arranged parallel to the direction of the stuffing and the layer 40 of fat is placed to remain on the outer surface of the mass of meat after stuffing. When the door 42 of the meat loading chamber is closed, a limit switch 44, shown in FIG. 5, is actuated to trigger the operating cycle of the apparatus. All subsequent operations by the device constitute an automatic cycle. The retainer carriage 20 moves to the stuffing position, as shown in FIG. 4. The latches 46 of the meat load chamber door are actuated by the jacks 48. The product compression bar 36 is moved laterally by jacks 50 to compress the mass of meat to an initial diameter "A" shown in Figure 5. When the compression side bar 36 is advanced to the maximum, it is

locked in position.

  The piston 54 of the first stage, controlled by a pneumatic cylinder 56, pushes the mass 32 of meat into the

  central support tube 30, as shown in FIG.

  At the end of the stroke of this piston 54 of the first stage, the piston 58 of the second stage begins to push the mass of meat in the central support tube and in a narrowed section of the envelope 60 for food products. The piston 54 of the first stage then assumes the function of cylinders

  pneumatic control piston 58 of the second stage.

  When the mass of meat is pushed from the loading chamber 34 into a narrowed end of a casing 60 previously attached, it is preceded by a relatively large volume of air. This volume of air is retained between the mass of meat and the attached end of the envelope and is proportional to the volume of the central support tube. Means shall be provided to allow the escape of air during jamming of the ham in the central support tube and in the casing to prevent swelling and opening of the attached end of the ham. envelope. Vents 62, formed in the calibration disk 26, allow the air to escape, the retained air can pass through these vents and escape between the wall of the light 64 of the stick formed by the pleated envelope and the outer surface of the support sleeve 24. The importance of this ventilation of the air and other means realizing it

are described previously.

  The application of continuous pressure on the meat mass and the dimensional control are maintained

  during stuffing by the application of a restraining force.

  This retaining force can be exerted by cooperation of the retaining ring 28 of the calibration disc 26, in a manner similar to that described in the aforementioned patent NI 4,077,090. Although a sealing ring 66 cooperates with the central support tube 30 to prevent the meat from coming back in the sections of the envelope being unfolded which are not yet filled, the clearance between this ring of sealing and the central support tube then allows to escape freely from the casing and to flow through the vents 62 of the disc 26 of calibration. The pressure exerted on the mass of meat is maintained during the stuffing and the installation of the fasteners, which avoids having to proceed to a

  separate and subsequent operation of ligation to the press.

  At the end of the second stage piston stroke, as shown in FIG. 7, the jack 68 expanding the casing moves the pleated rod mounted on the support sleeve 24 forward and backward. This action provides a free envelope stub. The piston 58 of the second stage remains in position at the discharge end of the central support tube 30 while the expansion operation of the envelope has

  place, which keeps the pressure on the product wrapped.

  The portion of the casing immediately behind the wrapped meat is tightened and attached by means of a second fastener device 70. The compression bar 36 is unlocked while the piston 54 of the

  first stage and the piston 58 of the second stage are retracted.

  As the second fastener device 70 is still engaged, the restraint carriage 20 advances to the position of installation of the first fastener, as shown in FIG.

  figure 8, taking with him the wrapped product.

  When the piston, 54 of the first floor is totally

  retracted, the compression side bar 36 retracts.

  The latches 46 of the door of the meat loading chamber are released and the pneumatic cylinder 72 opens the door

  42 of the room. The device is ready to be recharged.

  The reloading can begin while the first fastener is automatically placed on the free section of the envelope, behind the stuffed and ligated product, this first fastener being placed by the device 74. A knife 76 of sectioning the envelope then cuts the latter between the end closed by a fastener of the wrapped product and the first fastener. The two fastening devices are then opened and the cutting knife of the envelope is retracted. The retainer carriage returns to the "stuffing" position, as shown in FIG. 4, before the stuffing begins. If the holding carriage has not returned to the "stuffing" position at the moment the "start" switch 44 is actuated by manual closing of the meat loading chamber door 42, the jam is delayed automatically until the restraint carriage-has returned to the position of

"Stuffing".

  A preferred embodiment of the apparatus according to the invention can be constructed exactly according to the details shown in the figures. The elements of the structure of this apparatus are preferably made of stainless steel or aluminum, the plastic parts, for example the configured face of the compression side bar, being made of "nylon", high-density polyethylene or any other suitable material conventionally used for the handling of food products. The parts are preferably assembled by welding rigid parts that do not have to be dismantled for maintenance operations, the parts to be dismantled for such operations being assembled by means of nuts, lock washers, etc. The preferred form of energy used to operate the apparatus is compressed air available in a normal installation, for example at a pressure of 560 kPa, the control pressure being reduced in a pressure reducer station to a manometric value of 350 kPa. Experience has shown that the preferred value of the angle formed by the flared rear edge of the central tube defining the stuffing mandrel should be about 150 relative to the horizontal. This results in a gradual decrease in the area of the cross section of the meat, which prevents blocking or deformation of the flesh and the layer of fat. The ribs 82 of the side walls of the loading chamber 34, one of these ribs being shown on the face 35 of the compression side bar 36, are preferably made of stainless steel. Suitable grooves may be provided in the circumferential walls of the piston member to allow the piston to move along the guide members as it progresses into the article loading chamber. The surface of the piston element intended to come into contact with the articles may advantageously be pierced with vent holes so that, when it retracts from the discharge end of the central tube, it does not establish a depression. between the piston face and the end closed by a fastener of the next section of envelope to be filled. The establishment of such a depression would obviously tend to bring the envelope back into the central tube of the stuffing mandrel assembly, undesirably affecting the operation of the apparatus or slowing it down. Ruptures of envelopes can therefore be avoided by the mere presence of

  perforations in the piston face.

  The apparatus according to the invention described above and produced and dimensioned as shown in the figures can operate successfully at filling rates of 8 to 9 hams per minute, on batches of 30 hams. With well-trained staff, the device can reach the pace

  packing of 10 hams per minute.

  It goes without saying that many modifications can be made to the apparatus described and represented without

depart from the scope of the invention.

Claims (9)

  Apparatus for continuously tamping soft articles (32) in staple lengths of flexible tubular casing (60), characterized in that it comprises a frame (16), a set (18) with mounted stuffing mandrel on the frame, a central tube (30) for supporting the stuffing mandrel assembly, disposed coaxially with this assembly and having a discharge end (29) and an inlet flared end (31), a chamber (34) ) for loading an article which communicates with the flared end of the central support tube, a closure element (42) placed on the loading chamber and movable between opening and closing positions to allow lateral access to the loading chamber when this element (42) is in the open position, a compression element (36) extending longitudinally to the loading chamber which can be moved between a. position. and a feed position and having a configured face (35) forming a part of a wall of the loading chamber when this element (36) is in the advance position, a control device (50) connected operatively to the compression member to selectively move between its withdrawal and advance positions, a piston member (54) disposed axially and longitudinally with the central support tube of the stuffing mandrel assembly and having a face intended to come into contact with an article, a control device (56) operatively connected to said piston element and arranged and arranged to move said piston element in a plurality of steps constituting a cycle of which a first step consists of a moving in the loading chamber of an article, a first position in which the contact face with an article is disposed at the rear end of this chamber until a second position in which this contact face is disposed at the flared end of the central support tube, and a second step consists of a displacement in the central support tube, between a first position in which said face of contact with an article is disposed at the flared end of the central support tube to a second position in which the contact face is disposed at the discharge end of the central support tube, elements (62). are arranged and arranged to allow venting of air expelled from the central support tube and the article being packaged, a device (24) being adapted to hold the air pleated casing (60) disposed coaxially on the stuffing mandrel assembly,   device being designed and arranged to provide a   continuous delivery in unfolded envelope to be filled with said soft articles, and retaining elements (26, 28) being designed and arranged to retain the continuous envelope and unfolded while stuffing.   2. Apparatus according to claim 1, characterized   characterized in that it comprises means (74, 76) for fastening and cutting the envelope, intended to close by means of fasteners discontinuous lengths of envelope and to cut the envelope between the sections attached to train   separate lengths of product (78).   3. Apparatus according to claim 1, characterized   characterized in that the piston element comprises a first piston (54) which has a face intended to come into contact with an article, and a second piston (58) concentrically arranged in the first piston and also having a face intended to enter. in contact with an article, the contact face of the first piston and that of the second piston forming   together said contact face of said piston element.   4. Apparatus according to claim 3, characterized   in that the control device (56) connected   piston member is adapted to move the first and second pistons together in the first step and to move the second piston during the first step. second step.   5. Apparatus according to claim 3, characterized   in that the second piston has a face intended to come into contact with an article and pierced with vent holes.   6. Apparatus according to claim 1, characterized   characterized in that the article loading chamber comprises elements (82) for orienting and guiding the soft articles in a linear and precise manner when the piston member is moved from the first position of its first step to the 'to the second position of its second stage. 7. A method for filling a soft article in a flexible tubular casing, characterized in that it consists of: a) depositing a soft article in alignment with a tubular channel (30), near an end (31) of inlet of this channel b) compress laterally the soft article so that the area of its cross section is less than the value it had initially and is greater than that of the tubular channel; c) forcing longitudinally the soft and compressed article in the tubular channel; d) pushing the soft and compressed article into the tubular channel so as to bring it out through the other end thereof and into an end of envelope length closed by a fastener; e) providing continuously, under a certain holding force, a length of envelope at the same time that the soft article is pushed into the envelope, until said article is completely wrapped; f) continually ventilating the air, otherwise drawn into the envelope length, to pull it out of this envelope length during stuffing of the envelope with the soft article; g) closing by means of a fastener the length of envelope on the soft and wrapped article; and h) sectioning the soft and wrapped article (78)   the continuous length of envelope.   Method according to claim 7, characterized in that the holding force is sufficient to hold the soft article under constant pressure during operations b) to g).   9. A method according to claim 8, characterized in that the soft article is a piece (73) 3e; ianie and in that the retaining force is sufficient for this piece of meat is wrapped under a pressure large enough to avoid to have to compress and shape under pressure, then, the wrapped meat.