Abstract:
Disclosed herein is a food product portioning apparatus comprising: a rotary-to-linear movement device; a support device, such as a platform, connected to the rotary-to-linear movement for receiving the food product thereon and moveable to position the food product at a predetermined height; and a cutting apparatus to portion the food product at the predetermined height. Also disclosed is a method of portioning food product at a predetermined size. Applicable food products can include, but are not limited to, cheese and various other soft, malleable, portionable food products.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/258,703 filed Dec. 28, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention generally relates to the portioning of food product into portions having a predetermined size. In one aspect, the invention relates to forming cheese blocks of a predetermined size in a cheese block former.  
           [0003]    Food products are often produced in portions of predetermined size, the size corresponding to a particular weight, e.g., a 1-lb block, 2-lb block and so forth. One food product that is typically produced in portions of predetermined size is cheese. Cheese block formers are commonly used to produce large blocks or block portions of a variety of types of cheeses (e.g., cheddar, colby, monterey jack, mozzarella, brick, muenster, among others). They generally do so by means of providing a tower or column having a large interior area. Various aspects of cheese block formers are generally known and are taught in U.S. Pat. Nos. 5,572,925 and 6,180,153 each of which is incorporated herein by reference.  
           [0004]    At the top of the tower, a mixture of curd and whey is typically fed into the column under a vacuum. As the mixture flows down through the column, the whey is drained or otherwise extracted from the mixture. The curd, usually under its own weight, becomes a solid pillar of cheese as it flows in a downward direction through the column. More specifically, as the height of the pillar of curd increases within the column, the curd in the lower portion of the pillar is compressed by the weight of superimposed curd such that additional whey is pressed out of the pillar and the curd is consolidated into a compacted cheese pillar. The pillar or column of cheese is then cut into blocks using a cutting apparatus, such as a guillotine blade, often located adjacent the bottom of the tower. Thus, the cutting typically takes place near the bottom of the tower section. Following cutting, the cheese blocks are prepared for packaging and later shipment. A block former can be designed for independent operation and/or for operation in conjunction with one or more additional cheese block formers.  
           [0005]    As noted above, cheese blocks are cut into a predetermined size to provide a block having a particular weight. Since the interior of the column determines a known, fixed space in which to permit cheese to flow down and through, obtaining a cheese block of the predetermined size can be accomplished by portioning or cutting the cheese column at a distance or height that corresponds to a predetermined height. Of course, this presupposes that the block formers effectively produce cheese blocks having consistent weights and uniform moisture content from block to block. Assuming this to be the case, an actuator in operative association with the block former causes the lowering of the cheese block the distance corresponding to the predetermined cheese block height. The actuator is typically located inside of a finishing station, which is often disposed adjacent, and usually below, the tower.  
           [0006]    In the past, pneumatic actuators have been used to control and adjust the distance that the cheese block is lowered within the column to achieve a desired or predetermined height. These pneumatic devices, however, have been limited at least insofar as they have not provided a wide control range over which the block heights can be controlled or adjusted to achieve the desired weight. In addition, they have not provided the necessary control over the block lowering/raising speed as the block is raised or lowered to a height corresponding to the predetermined height. Servo-controlled linear actuators have also been utilized to control the block sizing operation. However, since servo-controlled linear actuators lack absolute feedback, they too have proven to be less than adequate in obtaining properly sized blocks of cheese (i.e., cheese blocks corresponding to the predetermined height). For instance, servo-controlled actuators require “homing”, meaning that they need to be brought to a known and repeatable position every time the power is turned off and back on again. In addition, servo-controlled actuators are typically quite complex and costly to implement.  
           [0007]    Accordingly, it would be desirable to design a device that can provide properly-sized portions of food products, such as cheese. The device would ideally solve the aforementioned problems, thus allowing even rather large blocks of cheese, or other like food product portions, to be produced in a cost effective, rapid, and reliable manner. Such a device would ideally be rugged and easy to use, thereby permitting the cheese blocks or other food product portions to be produced with a minimum of apparatus downtime.  
         SUMMARY  
         [0008]    The present invention generally provides for the portioning of food products, such as cheese, into portions of predetermined size. More specifically, the invention provides for food product portioning which overcomes the aforementioned problems.  
           [0009]    Various embodiments of the present invention include, but are not limited to: a cheese block former comprising a finishing station; a cheese block former for making large blocks of bulk cheese from a cheese curd mixture, the former having a finishing station; a cheese block portioning station; a finishing station for use with a food product; a food product portioning apparatus; a method of portioning a column of cheese to obtain a cheese block of a desired size; and a method of portioning food product at a predetermined size, among others.  
           [0010]    Generally, a device, system, and method that permits a food product, such as cheese, to be portioned without the need for homing is provided. Accordingly, in one embodiment for food product portioning is accompanied by effectively and appropriately controlling the weight of food products, such as cheese, in response to the food product height. Flexibility is provided to an end user, as least one aspect of the flexibility characterized in that the end user can obtain a desired food product portion, the portion corresponding to a predetermined food product portion height. A system is provided that permits a food product to be portioned at a programmable speed. A properly-portioned food product, such as cheese, can be provided by an apparatus that permits an infinitely adjustable and programmable food product size corresponding to a programmable food product height. Portioning of a food product, such as cheese, is accomplished in a manner that is cost effective, simple to implement and operate, and rugged, so as to minimize any downtime. 
       
    
    
       [0011]    Various other features and aspects of the embodiments will be made apparent from the following detailed description and the drawings.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The drawings illustrate the best mode presently contemplated for carrying out the invention.  
         [0013]    In the drawings:  
         [0014]    [0014]FIG. 1 is a schematic front view of a portion of a cheese block former according to one aspect of the invention.  
         [0015]    [0015]FIG. 2 is a detailed partial schematic view of one embodiment of a lower portion of FIG. 1 comprising a finishing station.  
         [0016]    [0016]FIG. 3 is a partial cross-sectional view taken along line  3 - 3  of FIG. 2.  
         [0017]    [0017]FIG. 4A is a partial schematic cross-sectional view of a finishing station showing the cheese prior to being portioned into a cheese block.  
         [0018]    [0018]FIG. 4B is a partial schematic cross-sectional view of a finishing station showing the cheese being portioned into a cheese block.  
         [0019]    [0019]FIG. 4C is a partial schematic cross-sectional view of a finishing station showing a cheese block being discharged.  
         [0020]    [0020]FIG. 5A is a partial schematic cross-sectional view of a portion of a finishing station showing the cheese as it is lowered prior to being portioned into a cheese block.  
         [0021]    [0021]FIG. 5B is a partial schematic cross-sectional view of a portion of FIG. 5A showing the cheese portioned into a properly sized cheese block.  
         [0022]    [0022]FIG. 5C is a partial schematic cross-sectional view of a portion of FIG. 5A showing a cheese block lowered prior to its discharge.  
         [0023]    [0023]FIG. 5D is a partial schematic cross-sectional view of a portion of FIG. 5A showing a cheese block as it is discharged. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    In the detailed description of this invention, like numerals are employed to designate like parts throughout the same. Various items of equipment, such as fasteners, fittings, etc., in addition to various other elements and specific principles of their operation are omitted to simplify the description. However, those skilled in the art will realize that such conventional equipment and principles of operation can be employed as desired. It is understood that the described cheese block former can be utilized with a variety of food products. For purposes of explanation only, the operation of the block former for producing cheese blocks is described herein.  
         [0025]    [0025]FIG. 1 shows a cheese block former  10  situated adjacent to, and more particularly on top of, a finishing station  50 , which itself is positioned on a base  12  and supported by supporting legs  13 . As shown, the cheese block former includes an upper tower section  14  and a lower tower section  16 , which together form tower  30 . A block former comprising a single tower section is contemplated for use with the present invention. The block former further includes a curd feed inlet tube  18  to supply curd feed into the cheese block former, as well as a vacuum port  20  to draw curd into upper tower section  14  of the cheese block former from upstream equipment (not shown). Lower tower section  16  typically can include a vacuum port (not shown) connected to a source for providing vacuum (also not shown) that is used to draw whey away from the curd. Upper tower section  14  includes wall  15  having inner surface  15   a . Lower tower section  16  includes wall  17  having inner surface  17   a . The respective inner surfaces  15   a  and  17  define the interior area of the tower for holding and forming the cheese curd as it flows down through the column.  
         [0026]    While it should be understood that the cheese block former can be designed to include only a single tower section, if the tower includes upper and lower tower sections (as is shown), the sections can be separated by a vacuum separator  22 . A vacuum separator can permit different pressures to exist simultaneously in the upper and lower tower sections. The separator can comprise a mechanism such as a valve to permit the pressure differential. Alternatively, the separator can comprise a straight-through chute, which can include a rectangular, circular, or oval-shaped chute, as well as a cylinder, a tube, or any other similar type of hollow material conveying apparatus. U. S. Pat. No. 6,108,153 describes such cheese block formers in greater detail.  
         [0027]    Referring to FIG. 2, a detailed, partially schematic, view of the finishing station  50  is shown. The finishing station provides a sanitary area in which cheese block cutting, portioning, and pressing can take place. The station comprises an inner chamber  52  defined by an interior surface  53   a  of housing  53 , which is a housing supported by legs  13 , which, as mentioned above, rest on base  12 . An elevator  54  having an elevator shaft or arm  56  can retract downwardly and extend upwardly through the inner chamber  52 . The elevator movement is further characterized in that, with respect to the illustrated embodiment, it is coaxial with respect to the tower  30 . Elevator arm  56  is attached to, at its top end, a platform  58  having an upper surface  58   a  upon which food product, such as the bottom portion of cheese column  60 , can rest. Mechanical ejection ram  62 , operable here by a two-pronged shaft  64 , is connected to and driven by a piston or other actuator  65 . Ejection ram  62 , as illustrated, is aligned to extend and move linearly through inner chamber  52  to push a food portion, such as a cheese block, out access/exit door  66 . This will be discussed further in the description that follows.  
         [0028]    Cutting apparatus  68  includes a guillotine or blade member  70  having top surface  70   a bottom surface  70   b  and cutting edge  70   c . The cutting edge is preferably beveled with the leading edge adjacent to the top surface of the blade so as to facilitate the cutting of the cheese column into an appropriately-sized block of cheese. An actuating device  72 , such as a piston, can be used to move blade  70  between a first or retracted position (as is illustrated in FIG. 2) in which the finishing station chamber  52  is in communication with the lower tower section  16  above it (when the elevator  54  is retracted), and a second or extended position (not shown) in which the finishing station chamber  52  is closed off to the lower tower section  16 . Movement of the blade  70  is described in greater detail below.  
         [0029]    Referring now to both FIGS. 2 and 3, FIG. 3 illustrating a partial cross-sectional view taken along line  3 - 3  of FIG. 2, the finishing station also includes a rotary-to-linear actuator  80 . The rotary to linear actuator raises and/or lowers the elevator platform  58 , thereby raising and/or lowering the food product  60  resting thereon, such as the exemplary cheese of the illustrated embodiment. In a preferred embodiment, the rotary-to-linear actuator  80  comprises a rack and pinion assembly having a rack portion  81  comprising teeth  81  a (seen in FIG. 3) that mesh or engage teeth  82   a  (seen in FIG. 3) of pinion portion  82 . The rack portion  81  is preferably coupled directly to elevator arm  56  such that movement of the rack corresponds with movement of the arm. The rack  81  is preferably made of stainless steel. The pinion portion  82  is also preferably made of a stainless steel material, or alternatively, a composite material. Other suitable rotary-to-linear actuators can include, but are not limited to, ballscrews, jackscrews, and the like (none of which are not illustrated separately herein).  
         [0030]    Still referring to FIGS. 2 and 3, motor  84  (shown in phantom in FIG. 3) and gearbox  85 , which are typically fixedly connected to the finishing station  50 , are used to drive pinion portion  82 . The pinion portion in turn drives rack portion  81 . In one preferred embodiment, the motor uses or incorporates a Variable Frequency Drive, or “VFD”, which is described further below. One suitable motor for use in the present invention is a one (1) horsepower HP motor, three (3)-phase motor. A servomotor, dc motor, or other similar devices can also work to drive the rotary-to-linear actuator.  
         [0031]    A linear transducer, as noted previously, is an electronic position sensing means that can transmit a signal representative of an object&#39;s position. As shown in FIG. 2, absolute feedback of a cheese column displacement (upward or downward) is preferably obtained via linear transducer  86 . Here, the linear transducer is in operative association with the rack portion  81 , the rack portion is directly coupled to the elevator shaft  56  and the cheese tower or column  30  rests on the elevator shaft. Therefore, by sensing the position of the rack portion  81 , the linear transducer  86  can sense a signal that is representative of a cheese pillar displacement. This displacement corresponds to the height of the to-be-cut cheese block or other food product portion, and thus, as a practical matter, the linear transducer can sense and transmit a signal representative of the cheese or other food product portion height.  
         [0032]    In one preferred embodiment, the linear transducer  86  is a Linear Variable Displacement Transducer, or “LVDT”. Such a transducer itself can preferably include an ultrasonic time-of-flight sensor, a linear resistive element (for example, a reostat or potentiometer) and a magnet to obtain requisite position information. One linear transducer suitable for use in the present invention is a magnetostrictive transducer, available from Patriot Tm, located in Clawson, Michigan.  
         [0033]    Referring to FIG. 2, the linear transducer is in operative association with a controller  88 , for example, a Programmable Logic Controller (“PLC”). The controller, as shown, is also in operative association with motor  84 , blade actuator  72 , shaft actuator  65 , and transducer  86 . The controller can use the absolute feedback signal representative of the food product height to control these elements (described further below).  
         [0034]    To begin the cheese block portioning process, a desired or predetermined cheese block is established. FIGS.  4 A-C show partial schematic cross-sectional views of a portion of a cheese block tower system (i.e. the system in this case defined to include a finishing station  50 ) the food product (e.g., the cheese) shown as it is portioned to a predetermined size. In particular, FIG. 4A shows the cheese  60  (a lower portion of a cheese column) prior to being portioned into a cheese block  61  of predetermined or desired size. When the column of cheese  60  in the tower section  16  has reached a specified height (detected, for instance, by a separate height sensor that is not illustrated here), blade is withdrawn to permit the column of cheese to be drawn down onto elevator platform  58  under its own weight. At this point, the cheese can be lowered into inner chamber  52  of finishing station via the elevator  54 . In general, the distance D the cheese column is lowered prior to its being cut by the cutting apparatus represents the cheese block height. Further, and as noted previously, proper and consistent cheese preparation or forming ensures that this block height corresponds to the weight of the cheese block  61 .  
         [0035]    As noted above, the linear transducer  86  senses a linear displacement of the rotary-to-linear actuator  80 . Using the feedback signal representative of the position of the cheese column  60  that is generated by and transmitted from transducer  86  to the controller (FIG. 2), motor  84  and gearbox  86  move pinion portion  82  in counterclockwise fashion. This rotation is indicated by arrow  90 . The VFD which drives the motor receives a control signal that is generated by and transmitted from the controller. The control signal is representative of a speed command to the VFD, which is decelerated as the actuator nears its set-point, i.e., the predetermined height.  
         [0036]    In general, rotary-to-linear actuator  80  is driven by motor  84 . More specifically, pinion portion  82  is in meshing engagement with rack portion  81 , and the rack portion is coupled to elevator arm (shaft)  56  of elevator  54 . Thus, pinion portion ( 82 ) drives the rack portion  80  to raise and/or lower elevator platform  58  via elevator shaft  56  to which it is coupled. The downward action of the shaft is shown by arrow  92 . Ejection ram  62  is in its retracted position and door  66  is closed. It is noted that the phantom lines shown in FIGS. 3 and 4 illustrate an alternative position of the rack portion and transducer.  
         [0037]    Referring to FIG. 4B, once elevator  54  (via the rack portion  80 ) is positioned at a height corresponding to the predetermined height of a cheese block  61 , blade  70  is moved to an extended or closed position, and in so doing, the blade cuts a portion of cheese from the lower end of the column of cheese curd  60 . This action is shown by arrow  94 . Ejection ram  62  remains in its retracted position and door  66  is closed. In FIG. 4C, a cheese block  61  of predetermined height (i.e., having a height “x”) is shown discharged from finishing station  50 . Ejection ram  62  is in an extended position, as shown by arrow  63 , and door  66  is opened, permitting the cheese block to be pushed or otherwise forced out of the finishing station where it can be bagged or transported for further handling (not shown).  
         [0038]    FIGS.  5 A- 5 D are also partial schematic cross-sectional views of a portion of the finishing station  50 . In these figures, cheese column  60  is shown being portioned to a cheese block  61   a  having height x′ (versus height x of FIGS.  4 A- 4 C). In FIG. 5A, cheese column  60  rests on platform  58  of elevator  54 . Blade  70  is in an “open” or retracted position. Pinion portion  82  moves in a counterclockwise fashion, as indicated by arrow  96 . Elevator  54  is lowered, thereby lowering the cheese column  60 . This movement is indicated by downward arrow  98 . As described previously, the cheese column is lowered into inner chamber  52  of finishing station  50 , ultimately to a height corresponding to a predetermined height of the to-be-cut cheese block  61 . As noted earlier, this height corresponds to the desired weight of the cheese block. Ejection ram  62  is in its retracted position and door  66  is closed.  
         [0039]    In FIG. 5B, guillotine blade  70  is moved to its closed or extended position, and in so doing, the blade cuts a block of cheese  61   a  at a height x′ corresponding to the desired cheese block height, and thus, weight. This action is illustrated by arrow  100 , and once again, ejection ram  62  is in its retracted position and door  66  is closed. It is noted again that the phantom lines shown in FIGS. 5A and 5B illustrate an alternative position of the rack portion  81  and transducer  86 . Referring to FIG. 5C, elevator platform  58  is shown being lowered to a retracted position. This is performed so that the block  61   a  can be properly discharged from the finishing station. And in FIG. 5D, a sized block of cheese  61   a  is shown, the block having a height x′. The block is shown as it is being discharged from the finishing station. Access door  66  is opened and ejection ram  62  is actuated to push or eject the cheese block out of the finishing station where the block can encounter later handling and/or packaging. This action is shown by arrow  102 .  
         [0040]    Referring to FIGS. 4B and 5B, in one preferred embodiment, elevator  54  can also lift platform  58  so as to force the cheese block upward against bottom surface  70   b  of guillotine blade  70  so as to press the cheese block for a predetermined amount of time. Phantom lines  104  and  106  of FIGS. 4B and 5B, respectively, illustrate the compressive force that can be applied to accomplish pressing of the cheese block or other food product as necessary. A cheese block of desired size can be molded to have a finished surface(s) that is appropriate for later packaging. Blade bottom surface  70   b , elevator platform top surface  58   a , ejection ram  62  and access/exit door  66  can function as such a mold for the cheese block to achieve such obtain finished surface(s).  
         [0041]    In summary, weight of cheese blocks can be effectively controlled by the height of the block. An actuator inside of the block-forming machine lowers a column of cheese into a chamber to a predetermined height. In the past the actuator that has controlled this height adjustment has typically been pneumatic. Such pneumatic devices have lacked the necessary feedback to the controller and have been limited in their range of weight control. Other devices that have been utilized for this operation include, for instance, servo-controlled linear actuators. However, these types of actuators have proven to be too complex, expensive, and further, they have required “homing” due to the lack of absolute feedback.  
         [0042]    The present invention incorporates a rack and pinion assembly connected to a gearbox and motor. Absolute feedback of position is sent to the controller via a linear transducer. With this feedback, the PLC controls the motor by way of a Variable Frequency Drive (VFD). This gives the end-user what is in essence an infinitely adjustable and programmable block height range, as well as a programmable food product lowering speed.  
         [0043]    The present invention results in many advantages over existing concepts currently in place. The rack and pinion actuator assembly provides extreme ruggedness and simplicity and thus can be operated and maintained by fairly easily. In its various embodiments, the present invention provides the flexibility to program a food product height of any size. A column of food product, such as cheese, can be lowered at virtually any programmable desired speed. Absolute feedback from the linear transducer eliminates the need for “homing”. The device is also significantly less expensive to manufacture than previous solutions. Off the shelf components can be incorporated such that there is minimal lead-time to and/or from the vendor. More specifically, the invention can include a stainless steel rack driven by a pinion gear that can be made of stainless steel, or alternatively, a composite material. Other concepts that can work for rotary-to-linear assembly include ballscrews jackscrews, or other comparably component. Preferably, a 3-phase motor and gearbox drive the actuator, while a VFD controls the motor speed. Connected to the rack is a linear transducer that sends a signal proportional to the height of the rack to the PLC. Other motors that can be used include, but are not limited to: servo, stepper, AC or DC motors. A platform inside the chamber is attached to a shaft that can preferably be directly coupled to the rack.  
         [0044]    A preferred procedure for portioning cheese blocks of a predetermined size is provided here succinct fashion. Initially, the cutting apparatus door is closed and the elevator platform is in its lowered or retracted position (also called a “backed off” position). The elevator and its attached platform are then driven up using the rotary to linear actuator, which itself is in operative association with a motor and gearbox. The cutting blade retracts and opens the column to the inner chamber of the finishing station and the cheese column lowers onto the elevator platform. The platform is then driven via the rotary to linear actuator in conjunction with the transducer, controller and motor to the desired block height. The cutting blade extends or closes so as to cut or portion the cheese block at the desired block height. The elevator is then driven to the lowered or “backed off” position and then driven upward so as to press the block for a period of time. The elevator is then lowered again and the access door opens to eject the cheese block.  
         [0045]    An operator interface (not shown) is typically used to provide a means for entering or programming requisite product specifications (e.g., the product type, weight, and the like.) that are to be received by the controller.  
         [0046]    The present invention has been described with respect to its use with a cheese block former having a tower through which cheese product can move. However, those skilled in the art will understand that the present invention described in its various embodiments in detail above can function in conjunction with other types of food producing, processing and or handling devices in which food can move as the product is formed, portioned, and/or otherwise handled.  
         [0047]    The present invention is not limited to cheese block formers for use with cheese products. It is clear that the present invention can be used with other food products that can be sized or portioned as desired in accordance with the principals and elements described herein. Such other food products can include, for example, tofu, meats or meat products, cheese-like products, various dairy products, and other food products or materials that can be formed into blocks of varying shapes and sizes.  
         [0048]    The steps of the methods described and claimed herein are set forth to provide the teachings of best mode and preferred embodiments of the invention, for purposes of clarity and particularity, and are not provided by way of limitation. The steps can be combined, divided, interchanged or otherwise rearranged, with such and other changes alterations and modifications apparent to one of skill in the art and contemplated and within the scope of the present invention.  
         [0049]    In general, while the principles of this invention have been described in connection with specific embodiments, it is evident that the description is exemplary and not intended to limit the scope of the invention.