IE51398B1 - Method and apparatus for stuffing a boneless whole meat article into a casing - Google Patents

Abstract

A whole boneless ham is stuffed under continuous pressure into a preclipped end of a length of casing deshirred from a continuous shirred casing length while providing for the continuous venting of air from the interior of the casing length, the stuffed casing length being then closed by a clip. The ham is placed in a chamber 34, a lid 42 is closed, a piston is operated to compress the ham laterally and a piston 54 is advanced to force the ham into a tube 30 and the central part of the piston then continues to advance to push the ham right through the tube, into the casing as in U.S. Specification 4044426. Air escapes through holes 62 and between the shirred casing and its support. Rings 26, 28 hold back the casing from slipping forwardly as in U.S. Specification 4077090.

Description

This invention relates to meat packing, particularly to the stuffing of boneless whole meat articles into casings to· make unitary packaged meat articles and, more particularly, to the packaging of whole boneless hams into lengths of casing deshirred from a continuous shirred casing supply.

Techniques for the stuffing of continuous length flexible food casings with viscous meat emulsion are now fairly well known in the meat packing and processed meat industries. The more recent developments in this area of the technology utilize long shirred lengths of flexible tubular food casing for stuffing on high speed automatic stuffing apparatus to produce large size sausage products such as bolognas, liverwursts, and the like, as described, for instance, in considerable detail in U. S. Patents 4,017,941 to Raudys et al, and 4,044,426 to Kupcikevicius et al.

In another somewhat technologically related area of the meat packing industry, whole boneless meat articles, such as hams, have been packed into lengths of flexible tubular food casing and tied off at the ends to make discrete unitary packaged food articles. Such packaging techniques generally have involved slow and labor intensive operations. In such practice, a whole boneless meat article, a ham typically, is manually inserted loosely into a cut length of presoaked casing 2. which has been pretied or clip-closed at one end. Insertion of the ham into the casing is accomplished manually or is assisted by means of one or another commercially available meat presses. In a subsequent pressure packing operation, the ham is tightly packed within the casing, simultaneously expelling entrapped air and shaping the ham. The operator may also stick” the casing during the pressure packing operation, providing holes to further assist in expelling air from within the packed casing.

The open end of the packed casing is then tied or clipclosed to complete the encased food article. Typical pressure packing techniques for boneless meat articles are shown and described in U. S. Patents 3,115,733 to Tipper and 3,065,585 to Rumsey, Jr. Somewhat greater automation in the boneless whole meat article stuffing technology is shown and described in U. S. Patent 3,919,739 to Kawai. Kawai utilizes a continuous band casing soaker in combination with a carriage means to continually put the open casing end into registration with a nozzle of a packing element. With the casing soaked and thus in place, a meat article is loosely packed into the temporarily held casing length. After a first clip is applied, the unclipped end of the packed casing is pulled tight around the meat 25 article thereby shaping said meat article and expelling air entrapped within said packed casing. The unclipped end of the casing is then tied or clip-closed and the resulting encased meat article is severed from the casing supply feed length.

While the Kawai '739 apparatus represents an advance towards the goal of automatic ham stuffing, it does not provide a completely satisfactory technique. 3.

A significant disadvantage lies in the feeding of the casing being stuffed in a direction opposite the direction of progression of the articles being stuffed. Each stuffing action constitutes a sort of head on collision between the ham and the casing length into, which it is to be packaged. Since, because of the apparatus design, there is no way to continually stuff the continuous casing band in a unidirectional mode with the direction of progression of the hams in process, this counterflow \O relationship between the casing band and the hams constitutes an inherent mechanical inefficiency. Another factor in the '739 Patent technique which detracts from efficient packaging is that the hams are inserted into a loosely fitting casing which is subsequently drawn tight to shape said hams and to express air out of the package article. These and other inefficiencies and drawbacks are overcome by the present invention as will be appreciated from the disclosure herein.

With this then being the state of the art, the 2,o present invention was conceived and developed. 4.

According to a first aspect of the invention there is provided an appratus for the continual stuffing of boneless whole meat articles into discrete lengths of flexible tubular casing comprising a frame; a stuffing horn assembly mounted on said frame, said stuffing horn assembly comprising shirred casing holding means and a tubular passaqe means, said shirred casing holding means being arranged and disposed to provide a continuous deshirred supply of casing to be stuffed with said boneless whole meat articles; and said tubular passage means being disposed coaxially within said shirred casing holding means and having a discharge end, a main bore and a flared inlet end; an article loading chamber in communication with the flared inlet end of the tubular passage means; closure means on said article loading chamber movable between open and closed positions providing lateral access to said article loading chamber when in the open position; a compression means extending longitudinally of said article loading chamber, movable between a retracted position and an extended position, said compression means having a formed face which defines a wall portion of the article loading chamber, the cross-sectional area of said loading chamber when said compression means is in said extended position being larger than the cross-sectional area of the main bore of the tubular passage means, but smaller than the cross-sectional area of said loading chamber when said compression means is in said retracted position, whereby on moving said compression means from said retracted position to said extended position a boneless whole meat article when placed in said loading chamber is laterally compressed to a condition wherein its cross-sectional area is smaller than its initial cross-sectional area and larger than the cross-sectional area of the main bore of the tubular passage means, actuating means operably connected to move the compression means selectively into its retracted and extended positions; piston means disposed in longitudinally axial alignment with the tubular passage means of the stuffing horn assembly, having an article contacting face; actuating means operably connected to said piston means arranged and disposed to move said piston means in multistage operation sequentially in a first stage from a first position wherein said article contacting face is disposed at the rearward end of the article loading chamber, through said article loading chamber into a second position wherein said article contacting face is disposed at the flared inlet end of the tubular passage means, and in a second stage from a first position wherein said article contacting face is disposed at the flared inlet end of the tubular passage means, through said tubular passage means into a second position wherein at least part of said article contacting face is disposed at the discharge end of the tubular passage means and maintained there under pressure exerted by said actuating means until the discrete casing length which has just been filled is clip-closed; air passage means arranged and disposed for the venting of air expelled from said tubular passage means and from the package article being formed; holdback means arranged and disposed for restraining said continuous deshirred supply of casing during stuffing of said flexible tubular casing and casing clipping and casing severing means to clip casing discrete lengths closed, and to sever between clipped sections so as to make individual lengths of product.

According to a second aspect of the invention there is provided a method for the stuffing of a boneless whole meat article into flexible tubular casing comprising: a) depositing a boneless whole meat article in alignment with a tubular passage means adjacent an inlet end thereof; b) laterally compressing the whole meat article to a condition wherein its cross-sectional area is smaller than its initial crosssectional area and larger than the cross-sectional area of the main bore of the tubular passage means; c) longitidinally forcing the compressed whole meat article into the tubular passage means; d) pushing the compressed whole meat article through said tubular passage means to and through the end thereof and into a clip closed end of a casing length; e) continually supplying under a restraining holdback force, a casing length from an initially shirred supply thereof concurrently with the pushing of the pliable article thereinto until said whole meat article is completely encased; f) continually venting air, which would otherwise be entrained in the casing length, from the casing length as it is being stuffed with the whole meat article; g) clip closing the casing length on the encased whole meat article; h) maintaining said whole meat article under constant pressurization during steps (b) through (g) by combination of said holdback force of step (e) and the action of step (d); and i) severing the encased whole meat article from the continuous casing length.

Accordingly, the invention provides a method and apparatus for inserting a whole boneless meat article, such as a ham, into a preclipped end of a preshirred and mounted length of casing, under continuous pressure, while allowing the continuous escape of air tending to become entrapped during the insertion or stuffing process, gathering and clipping the open end of the stuffed casing while maintaining the encased product in a pressurized condition, gathering and clipping the deshirred end of a contiguous succeeding preshirred casing length, severing the completed stuffed product from the succeeding casing, and repeating the aforedescribed cycle after loading a next sequential meat article into the apparatus. 51308 The basic concept and development of the present invention involves the adaptation and application of some of the principles and features of large size sausage casing manufacture with automatic machinery, such as described in the aforementioned U.S. Patents Nos. 4 017 941 and 4 044 426, to automatic stuffing of whole boneless hams or the like meat articles into casing lengths to made discrete tightly packed encased food articles.

A principal objective of the present invention is to provide a fast automatic method and apparatus for the pressure packing of whole boneless hams, or similar meat cuts, into large size tubular flexible casings.

The invention further provides positive and consistently reproducible control over the continually formed products with minimal human labour and handling of the food product, and with an efficient and relatively uncomplicated apparatus.

An advantageous feature of the invention is its ability to use shirred and compacted casing lengths, such as those shown and described in U.S. Patent No. 4 007 761, which do not require any prestuffing soaking.

A further feature of the invention is its ability to effect size control of the end product if this is desired.

Still further advantageous features of the invention are its capabilities to stuff product with virtually complete elimination of entrained air, and to consistently make stuffed products with proper external fat cover and proper muscle orientation.

The invention further provides for the constant pressurization of the meat during stuffing and clipping, thus eliminating the need for a separate pressure packing or squeezing step operation to effect air removal and to shape the meat.

Further, and of significant import, is the invention's provision of greatly increased production rates with decreased operator manpower requirements.

Preferably locking means are provided to secure said closure means in the closed position and preferably said compression means comprises a compression bar.

In a preferred embodiment the piston means comprises first piston means disposed in longitudinally axial alignment with the tubular passage means of the stuffing horn assembly having an article contacting face and being movable between a first position wherein the article contacting face is disposed at the rearward end of the article loading chamber, and a second position wherein the article contacting face is disposed in the flared inlet end of the tubular passage means; second piston means disposed coaxially within said first piston means having an article contacting face reciprocally movable between a first position wherein said article contacting face is disposed in the flared inlet end of the tubular passage means and the second position wherein the article contacting face is disposed at the discharge end of the tubular passage means of the stuffing horn assembly.

The stuffing horn assembly which includes the tubular passage means with the inlet end and the discharge end serves as a conduit to convey whole boneless hams from the meat loading chamber connected at its flared inlet end into a casing which is deshirred from a mounted shirred casing supply stick arranged concentrically over the assembly. The meat loading chamber has a first end in communication with the flared inlet end of the tubular passage means, a chamber door including means for the closing, locking and automatic reopening of the door,and is provided with means for the lateral compression of a meat mass placed within said chamber. The second or rearward end of the meat loading chamber connects to a longitudinal product stuffing means comprising first and second pistons.

The longitudinal product stuffing means comprises a multistage piston adapted to be advanced and retracted longitudinally in axial alignment with the meat loading chamber and the tubular passage means.

The first stage of the piston array is adapted to move through the meat loading chamber to the flared inlet end of the tubular passage means and thereby advance a meat mass from the meat loading chamber into the tubular passage means. The second stage of the piston means moves concentrically through the first stage piston through the tubular passage means to its discharge end thus further advancing the meat mass completely into’a deshirred length of the prepackaged food casing article. The movement of the second piston means begins after the completion of the movement of the first piston means.

A support sleeve may be advantageously journaled on the tubular passage means and provides means adapted to mount and detachably secure a sizing disc which is implanted in a preshirred tubular food casing article used in the packaging method. In the embodiments illustrated in the drawing the sizing means or disc is adapted to allow the escape of air displaced from the tubular passage means during the stuffing operation. Said adapted disc also permits the continuous escape of any air which may be entrained within the encased food product as stuffing progresses. The air passes from the forward end of the section of casing being stuffed up over the discharge end of the tubular passage means of the stuffing horn assembly, through the space between the inner surface of the casing and the outer surface of the tubular passage means of the stuffing horn assembly and through the passages provided in the sizing disc. It is extremely important to emphasize at this point in the disclosure the necessity to provide for the escape of air which would otherwise be entrapped within the encased food product during the stuffing operation. Towards this end, various alternative forms of air venting may be provided. In the embodiment of apparatus according to the invention illustrated in the drawing, air vents 62 are provided in the sizing disc 26 In other embodiments of the apparatus according to the invention, those for instance wherein a sizing disc may not be involved in the apparatus but holdback of the casing is achieved by the application of an external peripheral force around the casing in a snubbing action, the provision for air vents may take the form of a loose sleeve fit between the tubular passage means and a support sleeve or a loose fit between the tubular passage means or the support sleeve and a sleeve holding the shirred casing in place. The venting of air rearward from the stuffing operation may also be accomplished by providing longitudinally extending flutes in the surface of the tubular passage means'. The air would thus pass through the longitudinally extending flutes or notches rearward to be expelled through the open end of the bore of the casing. Other forms of air venting will, in the light of this disclosure, undoubtedly occur to persons familiar with the art, and it is sufficient to note here that provision for air venting must he made in order to insure the elimination of air which would otherwise be entrapped in the finished product, this provision being by any of the aforedescribed structural features or their combinations or their equivalents.

The prepackaged food casing article utilized with this apparatus, comprising a sizing/air venting means and a preshirred tubular food casing, is preferably like those described in detail in U.S. Patent 4,007,761. The support sleeve is adapted to be reciprocated to-and-fro to thereby manipulate the secured sizing/air venting means to predetermined fore-and-aft positions while supporting the shirred tubular casing thereon.

The apparatus also employs a snubbing means 10 including a snubbing carriage adapted to be axially aligned with the tubular passage means of the stuffing horn assembly and mounting an annular snubbing ring adapted to be advanced over and retracted therefrom.

The snubbing means coacts with the sizing/air venting means to effect product size (diameter) control in the same manner as that described in U. S. Patent 4,164,057. The snubbing carriage also mounts conventional clip-closing means and a severing means. In its retracted position, distally spaced from the stuffing horn assembly, the snubbing carriage is also adapted to be moved transversely from and to the axis of the tubular passage means to permit the loading and securing of the prepackaged shirred casing article onto the support sleeve means.

Motive means are provided to operate the support sleeve means and the snubbing means to regulate the position of the snubbing means with respect to the tubular passage means and the position of the support sleeve means relative to the snubbing means. 5133» Pneumatic actuation and control means are used to operate the support sleeve means, the meat loading chamber locking means, the lateral compression means, the longitudinal product stuffing means, and other elements of the snubbing carriage, in combination to selectively control continual cycles of successive compression, stuffing, clipping, and severing operations, and thereby produce a pressurized, stuffed, clip-closed whole boneless ham product encased in a flexible tubular casing.

It should be pointed out that while the disclosed embodiments utilize full pneumatic control, hydraulic electro/pneumatic actuation and control means would be fully satisfactory alternatives.

The present invention will now be described further, by way of example only, with reference to the accompanying drawings, in which:14 Figure 1 is a sectionalized side elevation of apparatus according to the invention showing a boned whole ham in position in the apparatus loading chamber; Figure 2 is a partial top view of the apparatus of Figure 1 showing the manner in which the meat article to be stuffed is initially put under compression; Figure 3 is a sectional view of Figure 2 taken along lines 3-3 showing an end view of the loading chamber and meat compression apparatus; Figure 4 is the apparatus of Figure 1 shown with the loading chamber cover closed and with lateral compression fully effected; Figure 5 is a sectional view of Figure 4 taken along the lines 5-5 showing an end view of the meat article in the chamber in its compressed condition; Figure 6 is the apparatus of Figure 1 shown with the meat article pushed into and partially through the stuffing horn by the first piston means; Figure 7 shows the meat article pushed completely through the stuffing horn and into the casing by the second piston means; Figure 8 shows the apparatus of Figure 1 with the meat article completely encased, the casing severed, the piston means fully retracted, and with the loading chamber opened; and Figure 9 is an isometric view of the loading chamber illustrating the product orientation guides or ribs.

Turning to the drawing, Figure 1 shows apparatus according to the invention comprising a frame 16 on which is mounted a stuffing hofn assembly 18, The stuffing horn assembly comprises in turn a tubular passage 5 means having a discharge end 29, and a flared inlet end 31. Rearward and communicating with the flared inlet end 31 of the tubular passage means 30, an article loading chamber 34 is provided. Article loading chamber 34 has a door' or other closure means 42 which lifts hingedly or slideably to permit access to the article loading chamber. When the closure means 42 of article loading chamber 34 is in-its fully open position, the chamber appears as shown in Figure 2, that is to say with its maximum volume condition available for loading the article to be packed.

Figure 3 of the drawing shows an end view of the apparatus in this condition. Loading chamber door lock cylinders or locking means 48 are provided to secure the closure means 42 in the closed position.

An article compression bar 36 extends longitudinally of the article loading chamber 34 and is provided with a formed face 35. Compression bar 36 is actuated reciprocally by lateral compression bar cylinders 50 shown in Figures 2 and 3 in the retracted position.

When these actuating cylinders are energized the compression-bar 36.is extended to the position shown in Figure 5 of the drawing wherein the formed face 35 defines a wall portion of the article loading chamber 34.

A multiple acting piston arrangement is provided comprising first piston means 54 and a second piston means 58, arranged in alignment with the article loading chamber 34 and with the tubular nassage means 30 of •S' the stuffing horn assembly 18. In the embodiment shown, the second piston means 58 is arranged coaxially within a cylinder formed in the first piston means 54 so that initially, the two units together constitute one acting piston. The pistons may be served by one face of the second piston or, alternatively, as in the embodiment of the drawings, be provided with separate article contacting races, one being annular in form and being in effect the rim end or edge of the first piston means 54, and the other circular in form being the face of the second piston IS means 58. In any case, it is only necessary that the piston means be provided so as to operate in two stages, one stage to push the laterally compressed body of meat or whatever other pliable article is involved forward through the loading chamber when it is in its closed 20 condition into and through the flared end of the tubular passage means and then, in the second stage of operation, completely through the tubular passage means to the discharge end thereof where the meat is put into contact with the clip closed leading edge of the casing being filled. In order to avoid the possibility of trapping portions of meat between the end of the first piston means 54 and the flared inlet end 31 of the tubular passage means 30, the face of second piston means 58 should never be allowed to extend beyond the rim end or edge of first piston means 54 until the stuffing motion of first piston means 54 has been fully completed.

The embodiment illustrated in the drawing provides for the front end mounting of a shirred casing 3>5 stick 22 coaxilly disposed on the support slebve 24 of the stuffing horn assembly 18. The casing mounted in this manner is controlled with regard to its movement by means of a sizing disc 26 mounted in a retainer recess in the support sleeve 24 and controlled with regard to maintaining feed pressure as it is being deshirred by means of a casing slack cylinder 68.

The operable features and characteristics of the casing stick 22 as it is controllably deshirred in this manner are the same as those explained in U. S. Patent 4,044,426. A snubbing carriage 20 is provided at the |0 front or discharge end of the apparatus and comprises clipping means 70 and 74 and severing means 76 to clip the casing discrete lengths closed and to sever between clipped sections so as to make individual lengths of product 78. An automatically actuated pneumatic cylinder 56 is arranged with one end fixed and a moveable end attached to a yoke which drives the multistaged piston means 54, 58 through, its sequential cycles .

In a given instance, it is conceivable that lo someone may to wish to operate the apparatus according to the invention without the clipping and severing features, that is to say to perform these functions at some other point in the production line.

Figure 9 of the drawing is an isometric illustration of the article loading chamber shown in open condition and with the piston means disposed in free body orientation, the lateral compression bar 36 and its actuating cylinders 50 shown in their retracted position, and illustrating an embodiment of the invention which involves the employment of ribs 82 arranged longitudinally in the wall portions of the loading chamber. One of the ribs 82 is incorporated into the lateral compression bar as shown and the other two are arranged in the arcuate wall of the fixed portion of the article loading chamber. The purpose of these ribs when used in an embodiment of apparatus according to the invention, is to provide IO orientation lands or rifling features for the guidance of the ham being packaged in a correct- and accurate linear mode. It has been found in practice that the inclusion of such ribs in the apparatus avoids the problems of muscle and fat disorientation and the unattractive twisting of the ham product as it is being stuffed into the stuffing horn assembly and the casing.

The typical mode of operation is as foilows:The snubbing carriage 20 is moved to the trans'Λο verse loading position. A prepackaged shirred food casing article 22 is placed on the support sleeve 24, attachment being made via the fingers of the sizing disc 26.

The snubbing carriage 20 is then moved transversely so that the central axis of the snubbing ring 28 is aligned with the central axis of the tubular passage means 30.

With the apparatus in the reset position, Fig. 1, a whole boneless ham 32 is placed in meat loading chamber 34. As shown in Figs. 2 and 3, the initial position of lateral compression bar 36 allows adequate space laterally, and the depth of the meat loading chamber (approximately 5 inches compared to the tubular passage means diameter of approximately 3.5 inches or less)-allows adequate depth so that the meat mass can be properly arranged preparatory to stuffing. That is to say the ham muscles 38 are arranged to lie parallel to the direction of stuffing, and the fat cover 40 is positioned so that it remains as the outside layer of the meat mass after stuffing.

\O As the meat loading chamber door 42 is closed, limit switch 44 shown in Figure 5 is activated initiating the machine cycle. All subsequent machine actions are automatically sequenced. The snubbing carriage 20 moves to the stuffing position, as shown in Fig. 4.

Meat loading chamber door locks 46 are activated by cylinders 48. The product compression bar 36 is moved laterally by compression bar cylinders 50, compressing the meat mass to initial diameter A as show, in Fig. 5. When the lateral compression bar 36 is fully extended, 2.0 it is locked in place.

First-stage piston 54, activated by pneumatic cylinder 56, pushes the meat mass 32 into the tubular passage means 30, as shown in Fig. 6. At the completion of the stroke of first-stage piston 54, second-stage piston 58 starts pushing the meat mass through the tubular passage means and into a deshirred section of food casing 60. The first-stage piston 54 serves as the pneumatic cylinder for the activation of the’secondstage piston 58.

As the meat mass is pushed from the meat loading chamber 34 into a deshirred end of the preclipped casing 60, it is preceeded by a relatively large volume of air. Said volume of air is entrapped between said meat mass and the clipped end of the casing, and is proportional to the volume of the tubular passage means. Provision must be made for the release of said air as the ham is stuffed into the tubular passage means and into the casing so as to avoid blowing the clipped end of the casing open. Air escape lo paths are provided by means of vents 62 in sizing disc 26, allowing entrapped air to pass through said vents and escape between the bore 64 of the shirred casing stick and the outer surface of the support sleeve 24. The importance of and alternative modes of air venting are discussed hereinabove.

Continuous pressurization of the meat mass and size control of the stuffed product are maintained during stuffing through the application of a holdback force. Said holdback force may be achieved through the coaction of 2.0 annular snubbing ring 28 and sizing disc 26 in a manner similar to that described in U. S. Patent 4,077,090. While sealing ring 66 coacts with tubular passage means 30 to prevent meat product from backflowing into the as yet unfilled zones in the deshirring casing, the clearance between said sealing ring and said tubular passage means allows the free escape of air from the casing to and through the vents 62 in the sizing disc 26. Pressurization of the meat mass is maintained during stuffing and clipping, eliminating the necessity for a separate and subsequent 2>o press-tying operation.

Upon completion of the stroke of th'e secondstage piston as shown in Fig. 7, the casing slack cylinder 68 extends and retracts the shirred stick mounted on support sleeve 24, This action provides a section of loose casing. The second-stage piston 58 remains in position at the discharge end of the tubular passage means while slacking takes place, thus maintaining pressurization of the encased product. The casing immediately behind the encased meat product is gathered and clipped by the second tie clipper 70. The compression bar 36 is unlocked as the first-stage piston 54 and second-stage piston 58 are retracted.

With the second tie clipper 70 still engaged, the snubbing carriage 20 indexes to the pretie clip position as shown in Fig. 8, carrying the encased product io with it. When the first-stage piston 54 has been fully retracted, the lateral compression bar 36 retracts. The meat loading chamber door locks 46 disengage, and the chamber door 42 is opened by pneumatic cylinder 72. The machine is now ready for reloading.

Reloading can proceed as the pretie clip is automatically applied to the loose section of casing behind the clipped-closed stuffed product by the pretie clipper 74. The casing severing knife 76 then severs the casing between the clipped-closed end of the lo encased product and the pretie clip. Both clippers are then opened and the casing knife is retracted. The snubbing carriage 20 returns to the stuff position as shown in Fig. 4, prior to the commencement of stuffing.

If the snubbing carriage has not returned to the stuff position at the time the start limit switch 44 is activated by the manual closing of the meat loading chamber door 42, the stuffing cycle is automatically ' delayed until the snubbing carriage moves to- said stuff position.

A preferred apparatus according to the invention can be constructed exactly in accordance with the detail of the figures of the drawing presented herein. The structural components are made preferably of stainless steel or aluminum with the plastic part thereof, such as for instance the formed face portion of the lateral compression bar, made of nylon, high density polyethylene or the like suitable materials conventionally used in the handling of food products .

Assembly of the parts is made preferably with welding for the rigid parts which are not to be disassembled for routine maintenance and with the parts that are to be disassembled for routine maintenance with nuts, lock washers, etc.

The preferred energy for actuation of the machine is standard plant air pressure at,for example, psig with control pressure reduced through a pressure reducing station to 50 psig. It has been found through experience that the preferred angle rate of the tapered edge at the rear of the tubular passage means which defines the stuffing horn should be about 15° from the horizontal. This presents a gradual reduction in the cross sectional area of the meat which avoids undue jamming or distortion of the muscle structure and fat cover. The ribs 82 installed in the side walls of the article loading chamber 34, one of them being shown in the face 35 of lateral compression bar 36, are preferably made of stainless steel. Appropriate notches can be formed in the circumferential walls of the piston means to accommodate passage of the piston along the guide members as the piston progresses through che article loading chamber. The article contacting surface of the piston means may advantageously be perforated with venting holes so that in retracting same from the discharge end of the tubular passage means, no vacuum will be formed between the piston face and clip vo closed end of the next to be filled casing segment.

The formation of such vacuum would, of course, tend to pull the casing back into the tubular passage means and create an undesireable malfunction or slow down the operation. Casing breaks can therefore be avoided by the simple expedient of including perforations in the piston face.

With an apparatus constructed in accordance with the above outlined specifications and physically and dimensionally in accordance with the drawing included in the application, apparatus according to the invention has been successfully operated at stuffing rates of between 8 and 9 hams per minute on 30 ham piece runs. With complete training of personnel who operate the machine it is possible to attain the rate of the packaging at 10 hams per minute.

Claims (9)

1. An apparatus for the continual stuffing of boneless whole meat articles into discrete lengths of flexible tubular casing comprising a frame; a stuffing horn assembly mounted on said frame, said stuffing horn assembly comprising shirred casing holding means and a tubular passage means, said shirred casing holding means being arranged and disposed to provide a continuous deshirred supply of casing to be stuffed with said boneless whole meat articles; and said tubular passage means being disposed coaxially within said shirred casing holding means and having a discharge end, a main bore and a flared inlet end; an article loading chamber in communication with the flared inlet end of the tubular passage means · closure means on said article loading chamber movable between open and closed positions providing lateral access to said article loading chamber when in the open position; a compression means extending longitudinally of said article loading chamber, movable between a retracted position and an extended position, said compression means having a formed face which defines a wall portion of the article loading chamber, the cross-sectional area of said loading chamber when said compression means is in said extended position being larger than the cross-sectional area of the main bore of the tubular passage means, but smaller than the cross-sectional area of said loading chamber when said compression means is in said retracted postition, whereby on moving said compression means from said retracted position to said extended position a boneless whole meat article when placed in said loading chamber is laterally compressed to a condition wherein its cross-sectional area is smaller than its initial crosssectional area and larger than the cross-sectional area of the main bore of the tubular passage means, actuating means operably connected to move the compression means selectively into its retracted and extended positions; piston means disposed in longitudinally axial alignment with the tubular passaqe means of the stuffing horn assembly, having an article contacting face; actuating means operably connected to said piston means arranged and disposed to move said piston means in multistage operation sequentially in a first stage from a first position wherein said article contacting face is disposed at the rearward end of the article loading chamber, through said article loading chamber into a second position wherein said article contacting face is disposed at the flared inlet end of the tubular passage means, and in a second stage from a first position wherein said article contacting face is disposed at the flared inlet end of the tubular passage means ; through said tubular passage means into a second position wherein at least part of said article contacting face is disposed at the discharge end of the tubular passage means and maintained there under pressure exerted by said actuating means until the discrete casing length which has just been filled is clip-closed; air passage means arranged and disposed for the venting of air expelled from said tubular passage means and from the package article being formed; holdback means arranged and disposed for restraining said continuous deshirred supply of casing during stuffing of said flexible tubular casing; and casing clipping and casing severing means to clip casing discrete lengths closed, and to sever between clipped sections so as to make individual lengths of product.

2. Apparatus as claimed in claim 1, in which'said piston means comprises a first piston having a face which forms part of said article contacting face and a second piston concentrically disposed in the first piston and having a face which forms part of said article contacting face, said face on the first piston and said face on the second piston together comprising said article contacting face on said piston means.

3. Apparatus as claimed in claim 2 in which the activating means operably connected to said piston means is arranged to move said first piston and said second piston together through said first stage, and said second piston through said second stage.

4. Apparatus as claimed in claim 2 or 3, in which said second piston has an article contacting face which is perforated with venting holes.

5. Apparatus as claimed in any preceding claim wherein said article loading chamber comprises means providing orientation and guidance of said whole meat articles in an accurate linear mode when said piston means is actuated from said first stage first position to said second stage second position.

6. A method for the stuffing of a boneless whole meat article into flexible tubular casing comprising: a) depositing a boneless whole meat article in alignment with a tubular passage means adjacent an inlet end thereof; b) laterally compressing the whole meat article to a condition wherein its cross-sectional area is smaller than its initial crosssectional area and larger than the cross-sectional area of the main bore of the tubular passage means; c) longitudinally forcing the compressed whole meat article into the tubular passage means; d) pushing the compressed whole meat article through said tubular passage means to and through the end thereof and into a clip closed end of a casing length; e) continually supplying under a restraining holdback force, a casing length from an initially shirred supply thereof concurrently with the pushing of the pliable article thereinto until said whole meat article is completely encased; f) continually venting air, which would otherwise be entrained in the casing length, from the casing length as it is being stuffed with the whole meat article; g) clip closing the casing length on the encased whole meat article; h) maintaining said whole meat article under constant pressurization during steps (b) through (g) by combination of said holdback force of step (e) and the action of step (d); and i) severing the encased whole meat article from the continuous casing length.

7. A method as claimed in claim 6 wherein said holdback force is sufficient to encase the meat article under pressurization sufficient to eliminate the need for subsequent pressure packing 15 and shaping of the encased meat.

8. Apparatus for the stuffing of a boneless wholemeat article into discrete lengths of flexible tubular casing constructed and arranged and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings. 20

9. A method for the stuffing of a boneless wholemeat article into a flexible tubular casing substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.