IE52213B1 - Rotable drum,particularly for food processing and door mechanism therefor - Google Patents

Abstract

A drum for the kneading of food pieces or the blending of food constituents is mounted on an inclined axis and there are spiral flights 24 along the side wall of the drum. Charging and discharging the drum is effected through an open end and the drum includes a door 23 for airtight sealing of the drum. A vacuum can be drawn via a pipe 46 to the drum for different types of processing or there can be pressure applied. A kneading action can be applied to massaging or tumbling meat chunks, and treatment liquids can be added to the drum and/or the food pieces for processing. Steam heating can be supplied. A door-operating mechanism for a door for the mouth of the rotatable drum includes a moveable arm 47 hingedly mounted with anchoring means 48 on the side of the frame of the drum. The arm may be coupled by clamps for connection with a stub shaft extending from the door. When the door is closed on the mouth of the drum, the clamps are disengaged from the stub shaft so that the door is secured, under vacuum pressure within the drum, as an integral part of the rotating drum. Force is thus avoided on the hinged, moveable arm, and stub shaft of the door and door-operating mechanism.

Description

This invention relates to processing food and products for food. In particular» the invention is directed to the kneading of a multiplicity of substantially integral food pieces, for instance, chunks of meat, fruits or cheese wheels or the like. The invention concerns the. processing of products in a rotatable drum, usually with the drum mounted on an axis inclined to the horizontal.

The invention also relates to a door-operating lo mechanism. Particularly, the invention is concerned with such a mechanism as applied to a door for a rotating drum in which products are processed.

The prior art of food processing is described with reference to the massaging and tumbling of chunks of meat, and in this regard the meat products are, for example, cured hams, ham products, bacon bellies, corn beef briskets, or fresh meats, such as, meat beef rounds, roasts, turkey breasts, or other poultry products. Such meats have been subjected to a tumbling or massaging in various kinds of known apparatus. -3Cured meat products are normally needle injected with a curing brine prior to mechanical tumbling or massaging at atmospheric pressure, or alternatively under a vacuum. The purpose of tumbling and massaging is to accelerate the curing process, improve distribution of the curing ingredient and to extract the bind protein myosin.

The extraction of myosin results in a sticky or tacky meat surface which improves moisture absorption and retention and enhances product coherency during processing.

Massaging boneless hams can improve and accelerate the distribution of injected curing brine resulting in a better cure in less time and, most importantly, the yield of the ham after cooking is increased by 5% to 7%. Tumbling of beef rounds or turkey breasts results in a condition that permits several pieces to be stuffed in casings or placed in molds for precooking. After chilling, the agglomerated meat can be thinly sliced without falling apart. Tumbling or massaging also results in other benefits such as improving uniformity of color, tenderness, pliability, control of shrinkage, and reduced cooking losses.

Generally, pale, soft meat such as pork and chicken is massaged while dark, firm meat such as beef, mutton and turkey is tumbled. Tumbling involves the result of impact energy influences on muscle such as would occur in allowing meat to fall from the upper part of a rotating drum, or striking it with paddles or baffles.

Massaging is a less physically vigorous process and involves frictional energy resulting from the rubbing of one meat surface on another, or on a smooth surface of a container.

Known apparatus for this massage processing includes vertical paddle massagers which are shown in U.S. Patent 4,038,426 (Jespersen) and U.S. Patent 3,934,860 (Michels). In such vertical paddle massaging, the paddles are -4suspended from above to engage the product, and the units may be portable and transportable from the brine injector lines to a process area. Unloading of the tanks is accomplished by tipping the entire unit with hydraulical5 ly actuated dumpers. Such paddle massagers are not suitable for bone-in ham due to product damage and are used almost exclusively for boneless ham production.

Even for such boneless products, the rotating paddles or stirring blades drag products through the mass of the load. This results in the tearing away and separation of pieces from the main chunks.

Vacuum massagers are basically of two kinds. One incorporates a drum or barrel shaped vessel which rotates in a horizontal position on powered rollers. Such a unit is internally equipped with longitudinal or angularly rotated shelves to effect lifting and mixing. The drum is loaded from the top while in a vertical position and then tilted down 90° for tumbling on rollers. Such massagers require considerable labor for loading and unloading. An example of such an arrangement is shown in U.S. Patent 3,860,067 (Hoffman).

The second kind of vacuum massager is of the sort illustrated in U.S. Patents 4,029,824 (Langen), 4,036,122 (Langen), and 3,746,316 (Langen). This system involves an elaborate *Y configuration vessel with one leg of the *Y detachable. The drum rotates about a central axis to allow the meat to tumble under the vacuum from one chamber to the next. This system usually involves several detachable chambers or round stainless steel meat tubs mounted on wheels which are used as product collection and transportation containers. Food containers are attached, to a conveyor system for indexing to the *Y drum area. Brine injector heads equipped with a pattern of injection needles may be provided in the two perma35 nent chambers. Because of the height from which the chunks of meat fall from chamber to chamber, damage in the sense of bruising the meat occurs. Where injector -5needles ace employed, tearing oc shredding of the muscle is additionally caused.

In the prior art of tumblers, it is known to provide atmospheric pressure tumblers which are horizontal drums, conical at each end and equipped with a manually operated door. Internal horizontal shelves effect the necessary lifting of the product. Such tumblers are used primarily for extracting the bind protein myosin in the preparation of precooked sectioned and formed beef products.

Vacuum tumblers incorporate a horizontal drum running on powered rollers and function much like a laundry tumbler in that it tilts to discharge. The product is loaded through a fold-away chute located at the drum center. The chute is pivoted out of the way and a vacuum door is placed over the charging opening during processing.

There are various other devices designed for other purposes that may have been used or tried by the meat processing industry from time to time, such as ribbon blenders employing helical paddles mounted on and rotated by a central shaft in a cylinder that are used in the chemical industry and small tilting drum-type concrete mixers, but insofar as can be determined, none of such devices has been considered satisfactory or successful, since they have not been adopted.

In the field of kneading food pieces and in view of the above limitations and disadvantages of the prior art, there is a need to provide a means for and method of food processing which can provide a gentle low speed rolling or massaging action on the food pieces.

In particular, with the processing of meat it is necessary to minimize bruising of the product and situations where static load conditions can cause tearoffs or separation. Also in regard to the vacuum tum35 bling or massaging of meat there is also the need to produce high quality meat products which are uniform in cure, bright in color, free of bruises with the entire -6meat structure intact and dense in mess.

Furthermore, there is a need for a single high productivity meat massager which permits for prompt processing of slaughtered animals, thereby to minimize the time during which muscles contract and rigor mortis sets in. There is thus a need for a masssager which requires less down time during which the curing brine would only penetrate through osmosis.

There is also a need for a processer which can operate both as a massager and a tumbler, and the prior art discloses units which are either only tumblers or massagers. In such a composite unit there is therefore the requirement for slow speed massaging and a higher speed dynamic tumbling where a requisite amount of physical abrasion is desirable.

Additional needs include those of a reduced capital cost, power, and handling requirements, working space and maintenance. It is also desirable to have a processor which is substantially more self-cleaning than existing processors.

By this invention there is provided apparatus and a method for kneading a multiplicity of substantially integral food pieces in a rotatable drum having spiralling flight means mounted about the inside wall between a closed end and an open end of the drum. Upon rotation of the drum, the food pieces are kneaded by contact with each other, with the type and magnitude of the kneading action being variable by changes in drum speed and direction of rotation. A further aspect of the invention includes door means provided on the open end of the drum, and, in some preferred forms of the invention, a means for drawing a vacuum in the drum during processing.

The invention also has application to various requirements in the processing of food products such as the blending of different constituents for a final food 53213 -7product, cooking food products and adding heat by steam injection or otherwise, introducing flavoring additives into the drum so as to process effectively the product as desired, either at atmospheric, vacuum, or above atmospheric pressure.

In some formsof the invention where there is a door there is provided a door operating mechanism for the door of the mouth of a rotatable drum which includes clamp means releasably to engage and disengage with a protruding shaft from the face of the door. There is an arcuately moveable arm mounted about anchoring means hinged on a support located adjacent the drum. The support is mounted on an extension of the foundation on which the rotating drum is mounted. The clamp means is mounted at the end of the moveable arm and is adapted to engage securely the door shaft until a predetermined vacuum pressure which is drawn in the drum, closed by the door, is reached. Release of the clamping means thereupon permits the door and drum to rotate integrally without imparting stress or force on the anchorage for the door.

When the vacuum is released and the pressure of the vacuum decreases towards atmospheric pressure, there is a movement effected by the arm axially relative to the rotating axis of the drum and away from the door. There is also a time delay prior to the clamp means again engaging the door shaft.

The mechanism includes a door swing cylinder for operating the moveable arm, and cylinders are provided for operating the clamping means. Vacuum sensing switches are operable with the cylinders and there is switching circuitry to effect a predetermined sequential operation of the cylinders of the mechanism relative to the vacuum pressure in the drum.

Adjustment bolts ace provided about the hinged anchorage support so that the moveable means through its hinge pin can be adjusted transversely and axially -8relative the rotational axis of the drum. The door can thus be adjusted relative to the drum mouth to adapt for manufacturing tolerances and misalignment due to wear as the drum rotates on its foundation.

According to the invention there is provided apparatus for processing a food product having a rotatable drum having a side wall, a closed end to the drum, and an open end for feeding the food product into the drum and discharging the food pieces from the drum, the open end being opposite the closed end; a mounting for the drum to permit drum rotation about a longitudinal axis extending between the ends at an incline to the horizontal, the mounting being connected with the drum at least about the side wall remotely located from the closed end, a spiralling flight mounted on the inside of the side wall of the drum and extending over at least a substantial part of the length between the closed end to the open end of the drum, and a drive adapted for drivingly engaging the drum thereby to permit drum rotation wherein said spiralling flight provides a configuration to cause continuous movement of substantially all the food product within the drum during drum rotation whereby for a food product being a multiplicity of substantially integral food pieces, there is a substantially kneading effect on said product and said food product pieces contained in the drum are kneaded by contact with each other.

In a preferred form of the invention where the food product is a multiplicity of substantially integral food pieces, the spiralling flight means has a configuration to cause continuous movement of substantially all the food pieces within the drum during rotation.

Also in some preferred forms of the invention there are door means mounted for movement between a position of closure with the open end of the drum and a position removed from the open end, said door means being adapted to form an airtight seal with the open end of the drum in the closed operative position. -9According to another aspect of the invention there is provided a method of operating a rotatable processing drum wherein food pieces are fed into the rotatable drum which is mounted with its axis inclined, said drum having a spiralling flight provided internally thereof, rotating the drum in a first direction about its axis whereby the food pieces contact each other, the rotation of the drum and the action of the flight tending to draw the food pieces inwardly into the drum and causing a continuous kneading effect on substantially all the food pieces throughout the drum, and reversing the direction of the rotation of the drum thereby to discharge the food pieces from the drum tinder the action of the spiralling flight.

The invention is further described with reference to the accompanying drawings, in which: Fig. 1 is a side view of the apparatus showing the drum partly in section, Fig. 2 is an end view along line 2-2 of Fig. 1 showing the drum from the open end with the door means closed on the end, Fig. 3 is a partial sectional side view showing details of a first embodiment of the door means and also illustrating, in phantom lines, the door means in an open position, Fig. 4 is a detailed sectional side view showing the engagement reinforcing flange of the door means with the engagement reinforcing flange about the open end of the drum.

Fig. 5 is a sectional end view through the drum along line 5-5 of Fig. 1 in the direction towards the open end of the drum, Fig. 6 is a sectional end view through the drum along line 6-6 of Fig. 1 in a direction toward the closed end of the drum, Fig. 7 is a detailed sectional end view through a vane of the flight means in the drum, and showing the connection of the vane to the side wall of the drum, -10Fig. 8 is a detailed sectional side view showing the hatch means in the side wall of the drum; Fig. 9 is an end view of a door-operating mechanism of a second embodiment of a door means for a rotatable drum with portion of the hinged anchorage for the mechanism being shown in section, and also showing the cylinders for operating clamp means of the mechanism; Fig. 10 is a side view of the door-operating mechanism of Fig. 9 showing a partial view of the door, a door swing cylinder and piston for the moveable arm together with solenoid vacuum valves for operating the door swing cylinder and cylinders of the clamp means; and Fig. 11 is a top view of the door-operating mechanism of Fig. 9 illustrating portion of the rotating drum, the door in abutment over the mouth of the drum, the moveable arm, the door swing cylinder laterally located on the support means adjacent the rotating drum, and also showing in phantom lines the door in the open position.

This invention is firstly described with reference to the embodiment illustrated in Figures 1 to 8.

The apparatus for kneading a multiplicity of substantially integral food pieces, such as chunks of meat, includes a rotatable drum 10 of stainless steel and having a glass bead blasted finish mounted on an axis inclined to the horizontal and suported by pedestals 11 and 12. The drum includes a side wall 13 made up of four segments 13a, 13b, 13c and 13d so that segment 13a tapers away from a closed end 14 to a larger diameter about the central section 13b and thereafter tapers at segments 13c and 13d gradually towards a smaller diameter at an open end of the drum 10. The closed end 14 of the drum 10 includes a centrally located internal conical housing 15. This housing 15 is formed by a portion 16 of end wall 14, a conical internal wall 17, and central circular segment -Ills inside the drum 10. The conical housing 15 defines an area through which a relatively conventional direct hydrostatic drive means 19 can be drivingly coupled to the closed end 14 of drum 10. The hydrostatic drive 19 is itself mounted on the pedestal 11 and thereby effects the drum mounting support axially at the closed end 14 of the drum 10.

Pedestal 12 is located about the side wall 13 remotely from the closed end 14 and thereby provides an additional mounting to the drum 10. On top of pedestal 12 there are rollers 20 on which a track 21 on the side wall 13d of the drum is adapted to run. In this manner, the drum is rotatable about its longitudinal axis which is inclined to the horizontal in a range between about 10° to 15°, preferably 12®.

The drum 10 provides an open end 22 which is closed by door means 23 as may be required in operation of the drum 10. The flight means are mounted on the inside of the side wall 13 and extend substantially over the length of the drum 10 between the closed end 14 and the open end 22. The flight means are defined by two spiralling vanes 24 which are 180° out of phase with each other and are mounted about the inside of the side wall 13 of the drum 10. The lead angle of the vane 24 is designed relative to the side wall segments 13a, 13b, 13c, and 13d such that upon rotation in a first direction the food pieces or food product 25 within the drum 10 are urged towards the closed end 14 of drum 10. Rotation in the opposite direction causes the contents 25 to be urged toward open end 22 and, when the door means 23 is opened, to be discharged through the open end 22 of drum 10. The lead angle in the central areas 13b and 13c of the drum 10 is about 26* and is somewhat less at the discharge section 13d of the side wall 13 due to the decreasing diameters of the side wall 13.

Vanes 24 meet the conical wall 17 at the closed end 14 substantially at right angles, and this is achieved by 82213 -12providing lips 26 substantially right angularly directed relative to the normal planar section 27 of the vanes 24. Such right angular engagement of the vanes 24 and wall 17 ensures that food pieces 25 do not wedge in a narrowing tight angle which would otherwise be formed if the vane sections 27 gradually tapered into engagement with the conical wall 17.

The edge 28 of vanes 24 provides a thickened crosssection 29 so as to minimize deleterious action on the food pieces during Operation of drum 10. Such action could be the bruising of chunks of meat, or unwanted severage of pieces of meat from the greater pieces 25.

The thickened cross-section 29 is formed by welding a tubular pipe section 29 on top of the plate forming the vanes 24.

The door means 23 is defined by a dish-shaped plate Centrally through the plate 30 there is provided a port 31 which is connected with a pipe 32. Between the port 31 and the interior of drum 10 there is provided a strainer 33 which prevents the passage of particles of food pieces into the port 31 and pipe 32. About the dish 30, there is a circular reinforcing flange 34 which is provided with a circular slot 35 in which is located a sealing ring 36. The flange 34 provides a tapered edge 37 relative to the plane of the dish 30 which is arranged to abut with a tapered edge 38 formed in a circular reinforcing flange 39 which is welded to the segment 13d at its end 40, namely the open end 22 of the drum 10.

The mating tapered edges 37 and 38 facilitate self30 aligning of the door means 23 with the open end 22 such that an air-tight seal can be created together with sealing ring 36 engaging with the tapered edge 38 as shown.

In the side wall 13 of the drum 10, there are two hatch means 54 and 55. The hatch means are offset from each other in a lateral and longitudinal direction. Each hatch means 54 and 55 includes an opening 56 in the a side wall 13, and a cover 57 which is arranged to move -13into and from engagement in an axial direction with the opening 56 such that effective sealing of the openings 56 can be made. A sealing ring 58 abuts with the mouth 59 around opening 56. Handle 60, and transverse bar 62 effectively provide for operation of the covers 57.

About the open end 22 to drum 10 there is a mounted shield 61 which covers the mounting rollers 20 and track 21 and effectively screens the opening 22 from those portions of the drum and drive mechanisms 19 and 14 rearwards of the shield 61 in the direction towards the closed end 14 of the drum 10. Affixed to the shield 61 is a delivery hopper 62 so that food pieces 25 discharged from the drum 10 can be fed suitably to a removal means.

A vacuum can be drawn in the inside of drum 10 through pipe 32 by means of a vacuum pump 41 which is mounted on the framework 42 below the drum 10. Generally, pipe 32 is defined by a lead section 43 which is connected with the port 31 and rotating union 44, and elbow 45 connected with flexible vacuum tubing 46 or the like.

A valve can be provided in the pipe 32 at any suitable place so that the vacuum pump 41 and drum 10 can be isolated from or connected with each other as desirable.

In some cases the union 44 may be removed and, after a suitable vacuum is drawn through the pipe 32, the valve is closed. The vacuum pump 41 is thus isolated from the door means 23 and drum 10.

The door means 23 is connected with an arm 47 projecting from and about the lead section 43 of pipe 32 to a mounting 48 laterally spaced from the side wall 12 of the drum 10. The mounting 48 of projecting arm 47 forms a hinge 49 about which the door means 23 is movable. By having the hinge 49 remote from the dish-shaped plate 30, there is sufficient flexibility permitted to the door means 23 such that the self-alignment of the door means 23 with the open end 22 is facilitated. From the mounting 48 there is a stub 50 which is connected with a piston rod 51 which passes into cylinder 52. Such a piston and -14cylinder means can be pneumatically driven through the supply pipes 53 to open and close the door means 23 as required. In operation of the processing apparatus the door means 23 is open and chunks of meat 25 are fed into drum 10. If desired, a curing fluid or the like 63 is also introduced into the drum to a requisite level. Alternatively the curing fluid 63 can be injected into the meat chunks 25 prior to loading into the drum 10.

Door 23 is then closed and the drum is rotated in a first direction causing a general force in a direction towards the closed end 14. This acts to massage the meat chunks 25 until the desired properties and characteristics of the meat chunks 25 are obtained. As required, the drum can also be rotated in a reverse direction and, in this event, with the door closed a different and opposite force is applied to the meat chunks 25, thereby imparting different properties to the meat chunks. In some processes, the drum can be retained stationary for desired time periods so as to impart other requisite characteristics to the food pieces 25 in the drum 10.

Discharge of the meat chunks 25 is effected by opening the door 23 and rotating the drum 10 in the appropriate direction such that the meat chunks 25 are drawn upwardly towards the open end 22 from where they fall into the delivery hopper 62 and are removed.

In another application of the invention when the door 23 is closed a suitable vacuum is applied to the drum, which could be up to about one atmosphere, by activating the vacuum pump 41. A pressure gauge 64 measures the vacuum within the drum 10. With the rotary union 44, the vacuum pump 41 is retained connected to the drum 10. In other cases, the vacuum tubing 46 can be disconnected from the door means 23. The vacuum acts to enhance the properties imparted to the meat chunks 25 and also increases the speed with such improved properties can be imparted to the meat. For different processes, -15different degrees of vacuum and pressure can be imparted to the drum 10.

In a particular example of the processor of the invention for massaging bone-in and boneless meat products, pieces weighing between 49 lbs. to 57 lbs. per cubic foot would be introduced into the drum 10. The pieces 25 are injected with up to 40% curing brine 63. Aside from the seepage of injected brine and a minor amount of free brine, there would be little float present in the load. During massaging all of the free moisture would be absorbed by the meat 25. Upon completion of the process, the load would be more viscous, yet, remain slippery and easy to handle.

The apparatus can be used for the kneading and processing of other food pieces. In this regard, examples are massaging of citrus products whereby the fruit is softened prior to squeezing or pulping. Likewise, the massaging of cheese wheels to effect homogenous conditions within the cheese is another process. There are also applications for the blending of food products and various components for food products in the apparatus. Also, there is the use of the drum for cooking food products, such as wheat kernels, under added pressure generated by a pressure pump or vacuum or atmospheric pressure. Heat can be added by steam injection or otherwise. Flavoring additives can also be suitably introduced.

Inspection of the contents of the drum 10 is made possible through the hatch means 54 and 55. By having the hatches 54 and 55 displaced on the drum 10 as indicated, inspection of different areas within the drum is possible. The hatch means also facilitate flushing of the drum during cleansing, by keeping in the cleansing operation, a cleansing fluid is added to the drum, the hatch means 54 and 55 are closed as is the door 23, and the drum is rotated in either or both directions so as to effect a suitable cleansing action. Thereafter, flushing 2 213 -16and draining is effected through the hatch means 54 and 55. or through the open end 22 when the drum 10 is rotated in reverse.

By having the ring 36 mounted in the flange 34 of the door means 23 it is possible to remove the ring 36 simply so as to facilitate the cleansing of the slot 35, and thus enhances the sanitation associated with the apparatus.

A suitable delivery hopper is provided on casters for feeding food pieces 25 such as meat chunks into the drum 10 and in this connection it is desirable that the delivery hopper have a chute which enters the open end 22 of the drum 10. This avoids spillage of liquid which has a high protein content and this can al.so avoid a loss in the final yield of the product.

The vacuum pump 41 can be mounted separately from the framework 42 in other embodiments of tbe invention. Automatic programmed operation of the vacuum pump 41 and hydrostatic drive 19 can be arranged so that preferred operation cycles of processing can be followed.

Advantages of the apparatus include the feature that the structure permits for the increased productivity with less equipment than prior art apparatus necessary for such productivity. For instance, one unit of the inven25 tion with a 15,000 lb. capacity is equivalent to nine vertical paddle massagers of 1,700 lb. each. Whereas the unit of this invention operating under vacuum requires only a 6 to 7-hour cycle time, the vertical paddle would require three times as much time for the same massaged end product. Similarly, a vacuum tumbler system of the Langen kind referred to in the prior art above would require two systems to equal the same production output.

Under atmospheric pressure, massaging occurs over a period of about 18 to 24 hours. The speed of rotation during massaging is normally about 2 to 4 rpm. Preliminary tests with the invention have indicated that a fast massaging of meat chunks is possible at a speed of about -1710 rpm without causing deleterious effects to the product.

The invented apparatus, operating on a gentle low speed rolling action or at the higher speed massaging, effectively provides a superior product with minimized damage, whether operating under vacuum or at atmosphere.

Furthermore, the massager can also tumble meat or other food pieces at atmosphere or under vacuum, at a speed up to 12 rpm and this versatility and multiple application of the invention is an additional important advantage and contribution of the invention in the art of food processors.

Initial capital costs are substantially reduced with the present invention as is the operating labor and expenses. The costs and labor for cleansing the apparatus are reduced and this can be effected at a rotational speed of about 10-12 rpm.

In different embodiments of the invention it is possible to have the lead angle of the vane 24 in the central areas 13b and 13c of the drum 10 -in a range between 20s and 45s. It apears that the most desirable is in the vicinity of 25° to 30°. One factor which will determine the desirable lead angle is the angle of inclination of the drum to the horizontal, which is also variable according to specific product requirements.

In yet a different form of the invention it is possible to have the hatch means 54 and 55 only longitudinally or only laterally offset from each other.

The hatch means 54 and 55 can be in a single section 13a, 13b, 13c, or 13d of the side wall 13, and the hatch means, can be midway between the vanes 24 of the flight means.

In place of the piston 51 and cylinder 52 being pneumatically operated, the door means 23 c»n be hydraulically operated or any other suitable actuator c»« be used.

In yet a further embodiment of the invention a different sealing arrangement between the door 23 and open end 22 is provided. The door 23 is arranged with a -18face, rather than a flange 34, which engages the perimeter of the open end 22, and between the face and perimeter there is a sealing 36.

In some embodiments of the apparatus the door is mounted on a support structure which is part of the foundation supporting the drum. Despite the correct alignment of the drum and door when the apparatus is new, it has been found that due to wear, for instance, of the rollers on which the drum is supported or due to manufac13 taring tolerance characteristics, a misalignment can take place between the mouth of the drum and the door which is used to close the drum mouth.

As it is important for this closure to be tight, so as to enable a suitable vacuum to be drawn, it has been found that the operating characteristics of the drum of the first embodiment of Figures 1 to 8 are not always as efficient as desirable. In view of this misalignment, undue stress can be placed on the drum mounting mechanism, and particularly the hinge formation of the door operating mechanism which is an extended part of the structure from the foundation on which the drum rests.

In the second embodiment now described with reference to Figures 9 to 11 there is a door-operating mechanism wherein a moveable container and the door to the mouth of the container are permitted to be aligned so as to minimize the misalignment due to wear or otherwise normal manufacturing tolerances, and prevent deterioration of the hinged support mounting for the door, and other deleterious effect on the support means of the door operating mechanism. There is also provided means for adjusting the relative position of the door with the drum, in a facile manner, so that effective sealing of the door with the drum mouth can be achieved.

A door-operating mechanism for a door 310 to the mouth 311 of a rotatable drum 312 includes clamp means 313. The clamp means includes a pair of levered elements 314 which each together define at their one end a pair of -19jaws 315. The jaws 315 are arranged to receive a hollow shaft 316 through which a vacuum can be drawn in the drum 312. Removed from the jaws 315, the lever elements 314 provide a common pivot point 317 with the end of an extension 31B remote to an arm 319 which is part of a moveable means 320 for moving the door 310 from a position closing the mouth 311 of the rotatable drum 312 to a position removed from the mouth 311.

Between the arm 319 and the extension 31β, there is a mounting plate 321 on which a pair of pneumatic cylinders 322 are fixed. The ends of the cylinders 322 provide pistons 323 which are connected to free ends 324 of the lever elements 314. The opposite ends 325 of the cylinders 322 are connected with a pneumatic power source through hoses 326 which are connected to the T-piece 327. The hose 328 is connected tc a pneumatic source through a solenoid valve 329 and a hose 330 as will be discussed in greater detail below.

The end 331 of arm 319 remote from the anchoring means 313 is secured to a tubular wall 332 forming a hinged anchorage means 333 for the door 310.

The tubular wall 332 is pivotally mounted about a central hinge pin 334 rotatable about an axis substantially rectilinear to the rotational axis 335 of the drum 312. The hinge pin 334 is held in position by means of two sets of four adjusting bolts 336 at the top and four adjusting bolts 336 at the bottom of the hinge pin 334.

The bolts 336 are circumferentially spaced around the pin 334 at approximately ninety-degree intervals.

The bolts 336 are threaded in a circular support ring 337 and by adjusting nuts 338 the relative projection of bolts 336 into interior of wall 332 can be adjusted. The hinge pin 334 of the hinged anchorage means 333 can be moved transversely and axially relative to the rotational axis 335 of the drum 312. Thus, alignment of the door 310 relative to the mouth 311 of the drum 312 can be accurately effected and adjusted -20to account for manufacturing tolerances and wear during operation of the drum 312.

Wall 332 forms together with bushings 339, spacer plate 340, and thrust ring bearing 341 a composite housing for the hinged pivoted anchorage means 333, A bracket arm 342 is affixed by bolts 343 to a post 344 of the foundation means 345 for the door operating mechanism. This post 344 forms part of the foundation means 345 on which the rotatable drum 312 is mounted. Between the drum 312 and the foundation means 345 there are rollers and tracks on which the drum 312 can rotate.

Supported below the hinged anchorage assembly 333 there is provided a bracket 200 on which is mounted the solenoid valve 329 and a solenoid valve 346. Hose 347 is connnected through elbow member 348 to an open door port 349 of a door swing cylinder 350. Hose 351 is also connected with elbow 348 and is connected to a closed door port 352 of the door swing cylinder 350.

Bracket 342 provides an end wall 353 which is bored 20 with an aperture to provide a shaft 354 which is an extension to the end 355 of the door swing cylinder 350. The shaft 354 is mounted on lugs 356 affixed to the end 355. Nuts 357 to either side of the end wall 353 permit for the adjustment of the shaft 354 and hence the adjust25 ment of the relative position of the door swing cylinder 350 in relation to the moveable arm 320. In this fashion, the effective degree of movement forward and rearward of the piston 358 is adjustable. Hereby the amount of movement or pressure of the door 310 on the 30 mouth 311 of the drum 312 can be, varied as required. The end of the piston 358 is provided with an eye 359 through which passes a bolt 360 to affix a pair of lugs 361 with the eye 359. The bolt 360 is affixed by means of a nut 362. The lugs 361 extend from the side wall 332 of the anchorage assembly 333 and as the piston 358 of the door swing cylinder 350 moves forwardly and rearwardly, the arm 319 is caused to move from the position wherein -21the door 310 is closed against the mouth 311 of the rotatable drum 312 or is removed from the mouth 311.

Around the perimeter 201 of the door 310, there are provided spaced lugs 202 which fit about the mouth 311 of the rotatable drum 312. These lugs 202 assist in aligning the door 310 with the mouth 311 such that if there has been undue wear or gross misalignment, interference will be encountered between the lugs 202 and the perimeter 201 of the outside of the wall 364 of the rotatable drum 312.

Tne hollow shaft 316 is affixed to the face 203 of the door 310 through a mounting plate 365 formed in the door face 203 substantially centrally about the rotational axis 335 of the rotatable drum 312. The end of the hollow shaft 316 for location on the mounting plate 365 provides a matching plate 366 which is suitably affixed by bolts 367 to the door face 203. The opposite end 368 of the hollow shaft 316 provides threads 369 for attachment of vacuum generating apparatus. Spaced inwardly of the threads 369, there is a collar 370 so that between another collar 300 on the stub shaft 316 and the collar 370 there is a defined space for accommodating the width of the jaws 315 between ends 204 and 205 of the lever elements 314 which effect anchorage with the door shaft 316. As illustrated in Figure 11, it will seen that a small gap 371, measuring approximately one-quarter inch, exists between the end of collar 370 and the end portion 372 of the jaws 315. This gap 371 exists when tne door 310 is closed about the mouth 311 and the arm 319 is extended in its furthest position as projected by the piston 358. In this position, the jaws 315 are in the position released or disengaged from the outside of the hollow shaft 316.

At commencement of operation of the door-activating mechanism, the jaws 315 are held fast with the hollow shaft 316 and the door is in an open position. After the drum 312 is loaded, the door is closed under action of -22the operating mechanism. After the vacuum pressure within the drum 312, as generated through the vacuum pump, reaches the predetermined level of 4 Hg, the jaws 315 of the lever elements 314 are released from the shaft 316 by activation of the pistons 323 of the cylinders 322. The drum shaft 316 is now free to rotate as is the door 310 as a substantially integral unit together with the rotatable drum 312. In this fashion, the force, movement and vibration to the shaft 316 and hinge mech10 anism of the anchorage means 333 on the post 344 through arm 319 is minimized. Effective sealing of the drum through 311 and door 310 is maintained in this manner with the minimum of wear on the shaft 316 and hinge anchorage means 333. There is retained a residual pressure in the door swing cylinder 350 so that after release cf the jaws 315 from the hollow shaft 316, the arm 319 swings slightly further inwardly towards the door face 203 under the residual pressure of the door swing cylinder 350. This creates the 1/4 inch gap between the end 372 of jaws 315 and collar 370.

In case of failure of the vacuum within the rotatable drum 312, the collar 370 insures that the jaws 315 are retained about the hollow shaft 316 so that although the shaft 316 is not restricted from rotating, the collar 370 and jaws 315 do restrict the door shaft 316 and door 310 from separating inadvertently from the arm 319.

As the rotatable drum wears during operation, any necessary adjustment to the position of the door 310 relative to the rotatable drum 312 can be effected by movement of the adjusting bolts 336 on the anchorage means 333 so that the door can be moved transversely or axially relative to the rotatable axis 335.

When the processing is complete, the vacuum is released and at about 4 Hg the door swing piston 350 causes the arm 319 to swing and the end 372 of jaws 315 to engage the collar 370. After a one-second time delay, the cylinders 322 are activated to cause the jaws 315 to -23clamp about the hollow shaft 316 and when the pressure within the rotatable drum is reduced to substantially atmospheric, the arm 319 under the action of the drum swing piston 350 draws the door 310 from the rotatable drum mouth 11.

Between the door 310 and the mouth 311 of the drum, there is provided an O-ring seal to insure that effective sealing of the closed drum can be achieved. The drum 312 provides on the inside 206 of wall 364 helical vanes or flights which permit processing of the drum contents, which can be food pieces such as meat chunks. The axis 335 of drum 312 is in this embodiment of the invention inclined to the horizontal axis so that drum rotation is effected at an incline. The end of drum 312 remote from the mouth 311 is a closed end.

Although, in the embodiment of the invention described, shaft 316 is hollow and is used for vacuum to be drawn in the drum 312, it is possible in other embodiments for the stub shaft 316 to be solid and for a suitable vacuum for the drum 312 to be provided at an appropriate central point on the axis at the closed end of the drum. In place of a stub shaft 316 for receiving the clamp means 313 an alternative receiving means on the door can be provided for engagement by the clamp means 313. Further, although a time-delay feature of one second has been described between the movement of the jaws 315 abutting the collar 370 and the time of engagement of the jaws 315 with the shaft 316, it will be appreciated that different time intervals can be set according to different predetermined operating characteristics.

In a different embodiment employing a door where the drum operates under atmospheric or higher pressure a suitable latching may be used to hold the door onto drum free of the mounting means. 53313

Claims (27)

1. Apparatus for processing a food product having a rotatable drum having a side wall, a closed end to the drum, and an open end for feeding the 5 food product into the drum and discharging the food pieces from the drum, the open end being opposite the closed end; a mounting for the drum to permit drum rotation about a longitudinal axis extending between the ends at an incline to the horizontal, the mounting being connected with the 10 drum at least about the side wall remotely located from the closed end, a spiralling flight mounted on the inside of the side wall of the drum and extending over at least a substantial part of the length between the closed end to the open end of the drum, and a drive adapted for 15 drivingly engaging the drum thereby to permit drum rotation wherein said spiralling flight provides a configuration to cause continuous movement of substantially all the food product within the drum during drum rotation whereby for a food product being a multiplicity of substantially integral 20 food pieces, there is a substantially kneading effect on said product and said food product pieces contained in the drum are kneaded by contact with each other,

2. Apparatus as claimed in claim 1, including a door mounted for movement between a position of closure with 25 the open end of the drum and a position remote from the open end.

3. Apparatus as claimed in either claim 1 or 2, including a moveable arm for mounting the door to open and close the door with the mouth, the moveable arm having a 30 clamp for selectively engaging or releasing the door from the moveable arm, the clamp being selectively operable to engage or release the door therefrom when the door is in closed position such that the door and drum can form an integral unit substantially free of the moveable arm and 35 the door can thereby rotate substantially freely with the drum. -254. Apparatus as claimed in Claim 3, wherein the clamp is adapted to engage the door when the door is in closed position with a vacuum within the drum below a predetermined level, and being adapted to release the door

4. 5 when the vacuum is above said predetermined level. 5. Apparatus as claimed in any one of claims 2 to 4, including a port to the interior of the drum for permitting the pressure in the drum to be changed relative to atmospheric pressure, said port being connected with a pipe, 10 and said pipe being adapted for connection to a vacuum or pressure pump.

5. 6. Apparatus as claimed in Claim 5, wherein the port is in the door.

6. 7. Apparatus as claimed in either Claim 5 or 6, 15 including a valve in the pipe thereby to permit the door opening and closure.

7. 8. Apparatus as claimed in any one of Claims 5, 6 or 7, including a rotary union in the pipe thereby permitting the pump to be continuously connected with the port during 20 drum rotation.

8. 9. Apparatus as claimed in any one of Claims 5,6, 7 or e, wherein the pressure change is in the range of up to substantially one atmosphere pressure.

9. 10. Apparatus as claimed in any one of Claims 2 to 25 9, wherein the door includes a dish-shaped plate extending outwardly from the drum and is adapted to form an airtight seal with the open end of the drum when in the closed position.

10. 11. Apparatus as claimed in any one of Claims 2 to 30 9, including a slot around the edge of the door said slot being adapted to accommodate a sealing ring for mating location against an adjacent mating edge around the open end of the drum. -2612. Apparatus as claimed in Claim 11. wherein the edge of the door means accommodating the slot is tapered relative to the plane of the door, and wherein the abutting edge of the open end includes a mating taper, said mating 5 tapered edge facilitating alignment of the door with the open end.

11. 13. Apparatus as claimed in any one of Claims 6 to 8, including a strainer element mounted on the door, said strainer being located inwardly of the port in the door 10 thereby to prevent the passage of food from the drum into the pipe.

12. 14. Apparatus as claimed in either Claim 3 or 4, wherein the moveable arm projects from the door, and said arm connects the door to a mounting laterally spaced from

13. 15 the side wall of the drum, said mounting providing a hinge for the door. 15. Apparatus as claimed in any one of Claims 3 to 5 or claim 14, including a powered actuator for activating the moveable arm of the door thereby to permit door 20 movement between the position of closure and opening.

14. 16. Apparatus as claimed in any preceding claim, including at least one hatch in the side wall of the drum.

15. 17. Apparatus as claimed in claim 16, including at least two hatches in the side wall of the drum, said 25 hatches being offset relative to each other.

16. 18. Apparatus as claimed in any one of Claims 1, 2, and 4 to 17, wherein the flight includes at least two vanes offset from each other.

17. 19. Apparatus as claimed in claim 18, wherein the 30 edge of the vanes remote from the side wall is thickened thereby to minimize deleterious action of the vanes on the food pieces or product.

18. 20. Apparatus as claimed in any one of claims 1, 2 and 4 to 18, wherein said flight provides a lip section in 35 a direction substantially right-angularly directed -27relative to the normal direction of the flight, and wherein said lip section meets the closed end of the drum at substantially right angles. ti. Appetiaiut: as claimed in any preceding claim, 5 wherein the product being processed includes chunks of meat, such chunks being massaged by kneading action.

19. 22. Apparatus as claimed in any preceding claim, including a supply for introducing heat into the drum during processing. 10

20. 23. A method of operating a rotatable processing drum wherein food pieces are fed into the rotatable drum which is mounted with its axis inclined, said drum having a spiralling flight provided internally thereof, rotating the drum in a first direction about its axis whereby the 15 food pieces contact each other, the rotation of the drum and the action of the flight tending to draw the food pieces inwardly into the drum and causing a continuous kneading effect on substantially all the food pieces throughout the drum, and reversing the direction of the 20 rotation of the drum thereby to discharge the food pieces from the drum under the action of the spiralling flight.

21. 24. A method as claimed in claim 23, wherein the drum is closed with a door after feeding of the food pieces thereinto.

22. 25 25. A method as claimed in claim 24, wherein the pressure in the drum is changed relative to atmospheric pressure.

23. 26. A method as claimed in claim 24, wherein the pressure in the drum is reduced below atmospheric pressure 30 during rotation thereof in said first direction.

24. 27. A method as claimed in any one of Claims 23 to 25, wherein a treating liquid is added to the food pieces in the drum. -282Ρ·. A method as claimed in any one of claims 23 to 2/, whet bin heat io introduced into the drum during food processing.

25. 29. A method as claimed in any one of claims 23 to 5 28. wherein the food pieces comprise chunks of meat.

26. 30. A method of operating a rotatable processing drum substantially as herein described with reference to the accompanying drawings.

27. 31. Apparatus for processing a food product, such 10 apparatus being constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings. F. R. KELLY & CO., AGENTS FOR THE APPLICANTS.