Separator for a food-product grinding machine with ring adjustment

A grinding machine for grinding food-products, such as meat or the like, includes an orifice plate at the outlet of a grinding head. The orifice plate has collection passages that discharge a mixture of soft material and hard material through the orifice plate. A separator assembly, including a separator screw and separation chamber, is located downstream of the orifice plate for separating the soft material from the hard material. A ring adjustment assembly includes a ring valve having an internal conical portion in communication with a nose portion of the separator screw, and a ring valve carrier configured to reciprocally displace the ring valve in an axial direction relative to the separator screw so as to vary a gap between the nose portion of the separator screw and the internal conical portion of the ring valve. Adjustment of the gap distance determines an amount of the hard material that is passed toward the discharge outlet.

BACKGROUND OF THE INVENTION

This disclosure relates to a grinding machine for foodstuffs such as meat, and more particularly to a recovery system for an orifice plate-type grinding machine that includes a hard material collection arrangement with a ring-based adjustment mechanism.

A typical grinding machine includes a hopper that receives material to be ground and an advancement mechanism such as a rotatable auger that conveys the material away from the hopper toward a grinding head. The grinding head typically includes a discharge opening or outlet within which an orifice plate is positioned. A knife assembly is located between the end of the auger and the orifice plate, and is typically engaged with the auger and rotatable in response to rotation of the auger. The knives of the knife assembly cooperate to shear the material as it is forced through the orifices of the orifice plate.

Systems have been developed for the purpose of preventing hard material from passing through the orifices of the orifice plate. In a meat grinding application, for example, such systems function to route hard material such as bone, gristle and sinew away from the grinding orifices of the orifice plate. Representative hard material collection systems are shown and described in U.S. Pat. No. 7,461,800 issued Dec. 9, 2008; U.S. Pat. No. 5,344,086 issued Sep. 6, 1994; U.S. Pat. No. 5,289,979 issued Mar. 1, 1994; and U.S. Pat. No. 5,251,829 issued Oct. 12, 1993, the entire disclosures of which are hereby incorporated by reference. Typically, hard material collection systems of this type route the hard material to collection passages located toward the center of the orifice plate, where the hard material is supplied to a discharge tube or the like.

The hard material that is discharged through the collection passages is typically contained within a mixture that includes both hard material and soft, usable material. Various arrangements have been developed to recover the soft, usable material within the mixture, some of which are shown and described in the above-noted patents.

SUMMARY OF THE INVENTION

Some embodiments of the present invention provide an improved system for recovering the soft, usable material in the mixture of hard and soft material that is discharged from hard material collection passages in an orifice plate-type grinding machine. Other embodiments of the invention provide such a system that requires little or no adaptation of the grinding components of the grinding machine. In other embodiments of the invention, such a system is capable of adjustment for accommodating different types of material.

In accordance with embodiments of present invention, a recovery arrangement for a grinding machine is in the form of a separator assembly located downstream of the orifice plate of the grinding machine. The separator assembly includes an upstream inlet that receives the mixture of soft material and hard material from the collection passages of the orifice plate, in combination with a separator chamber having a wall that defines an axially extending tapered separator passage. The separator passage receives the mixture of soft material and hard material from the upstream inlet. The wall of the separator chamber includes a series of perforations that communicate between the separator passage and an outer surface defined by the wall. The separator assembly further includes a separator screw disposed within the separator passage of the separator chamber. The separator screw is interconnected with the rotatable advancement member and is rotatable within the separator passage in response to rotation of the rotatable advancement member. Rotation of the separator screw causes separation of soft material from the mixture of soft material and hard material, and forces the soft material through the perforations in the wall of the separator chamber. The separator chamber defines a downstream end that includes an outlet for discharging hard material.

The separator assembly may include an open support extending outwardly from the grinding head, and the separator chamber is engaged with and supported by the support at a location downstream of the orifice plate. In one embodiment, a centering pin extends from the rotatable advancement member. The centering pin rotates with the rotatable advancement member and is engaged within a center opening defined by the orifice plate, and the separator screw may be engaged with the centering pin so as to be rotatable with the rotatable advancement member via engagement with the centering pin. Engagement structure is interposed between the centering pin and the separator screw for non-rotatably securing the separator screw to the centering pin. An adjustment arrangement is operable to adjust the axial position of the separator screw within the separator passage, and the engagement structure between the separator screw and the centering pin is configured to accommodate axial movement of the separator screw relative to the centering pin by operation of the adjustment arrangement. Representatively, the engagement structure may be in the form of a bore in the separator screw within which the centering pin is received, a transverse passage in the centering pin, a slot in the separator screw that overlaps the transverse passage, and a transverse engagement pin that extends through the slot and the transverse passage. With this arrangement, the slot accommodates axial movement of the separator screw relative to the centering pin.

In one embodiment, the support and the orifice plate are configured and arranged to prevent axial movement of the separator chamber. The adjustment arrangement may be carried by the support and interconnected with the separator screw for providing axial movement of the separator screw within the separator passage. The adjustment arrangement may be in the form of an axially extending threaded adjustment member that extends through the support and into engagement with a threaded passage extending inwardly from a downstream end defined by the separator screw.

In another embodiment the grinding machine includes a grinding head defining an opening and a rotatable food-product advancement member contained within the grinding head. An orifice plate is located within the opening of the grinding head, where the orifice plate defines an upstream surface and a downstream surface, and includes a plurality of outer grinding openings extending between the upstream surface and the downstream surface for discharging soft material through the orifice plate upon rotation of the rotatable food-product advancement member. One or more collection passages extend between the upstream surface and the downstream surface for discharging a mixture of soft material and hard material through the orifice plate upon rotation of the rotatable food-product advancement member. A separator assembly is located downstream of the orifice plate, wherein the separator assembly includes an upstream inlet that receives the mixture of soft material and hard material from the collection passages, a cylindrical separator chamber having a sidewall that defines a constant diameter separator passage, wherein the separator passage receives the mixture of soft material and hard material from the upstream inlet, and where the sidewall of the separator chamber includes a plurality of apertures, and a separator screw disposed within the separator passage of the separator chamber, and where the separator screw has a constant major diameter and may have a constant or variable minor diameter along a body portion thereof. In some embodiments, the minor diameter may be constant, while in other embodiments, the minor diameter may be fixed or constant. The separator screw is interconnected with the rotatable food-product advancement member and is rotatable within the separator passage in response to rotation of the rotatable food-product advancement member, where rotation of the separator screw causes separation of soft material from the mixture of soft material and hard material, and forces the soft material through the apertures in the sidewall of the separator chamber, and advances the hard material in the downstream direction toward a discharge outlet.

Also included is a ring adjustment assembly including a ring valve having an internal conical portion in communication with a nose portion of the separator screw, where the ring valve is in axial alignment with the separator screw. A ring valve carrier is configured to reciprocally displace the ring valve in an axial direction relative to the separator screw so as to vary a gap between the nose portion of the separator screw and an internal conical portion of the ring valve, wherein the size of the gap determines an amount, and in some embodiments, a size of the hard material that is passed toward the discharge outlet.

In another embodiment, a ring adjustment assembly for a grinding machine includes a grinding head in communication with a cylindrical separator chamber, where the cylindrical separator chamber has a sidewall that defines a constant diameter separator passage, and where the sidewall includes a plurality of apertures. The separator chamber has an inlet end and an outlet end, and the inlet end is configured to receive a mixture of soft material and hard material from an upstream portion of the grinding head. A separator screw disposed within the separator passage of the separator chamber, and has a body portion and a nose portion. Also includes is a ring valve having an internal conical portion in communication with the nose portion of the separator screw, where the ring valve is in axial alignment with the separator screw. A ring valve carrier is configured to reciprocally displace the ring valve in an axial direction relative to the separator screw so as to vary a gap between the nose portion of the separator screw and the internal conical portion of the ring valve. The size of the gap determines an amount of the hard material that is passed toward a discharge outlet of the ring adjustment assembly.

DETAILED DESCRIPTION

The present invention is directed to a separator assembly10that can be coupled to a discharge or outlet end of a grinding machine, such as grinding machine12. As generally known in the art, grinding machine12has a hopper14and a grinding arrangement shown generally at16. In a manner as is known, grinding arrangement16includes a housing or head18which includes a mounting ring20that secures and orifice plate32within an opening or discharge outlet in the downstream end of grinding head18. With reference toFIGS. 2 and 5, grinding machine12further includes a rotatable advancement member which may be in the form of a teed auger or screw26that is rotatably mounted within head18so that, upon rotation of feed screw26within head18, material is advanced from hopper14through the interior of head18. A knife holder28is mounted at the end of, and rotates with, feed screw26. Knife holder28has a number of arms30a-30fand a corresponding number of knife inserts, one corresponding to each of arms30a-f, and it is understood that any number of arms and corresponding inserts may be employed.

The knife holder28is located adjacent an inner grinding surface of orifice plate32, which is secured in the open end of head18by mounting ring20. The knife inserts bear against the inner grinding surface of orifice plate32. In accordance with known construction, the end of head18is provided with a series of external threads38, and mounting ring20includes a series of internal threads40adapted to engage the external threads38of head18. Mounting ring20further includes an opening42defining an inner lip44. While a threaded connection between mounting ring34and head18is shown, it is understood that mounting ring34and head18may be secured together in any other satisfactory manner.

A center pin52has its inner end located within a central bore54formed in the end of feed screw26, and the outer end of center pin52extends through a central passage56formed in a central hub area of knife holder28and through the center of a bushing58. In a manner to be explained, center pin52has a construction that is modified from that of a typical center pin, in order to accommodate the components of separator assembly10. Bushing58supports center pin52, and thereby the outer end of feed screw26. In a manner to be explained, bushing58also functions to support certain components of the separator assembly10relative to orifice plate32. The center pin52is non-rotatably secured to feed screw26, such as by means of recessed keyways (not shown) on center pin52that correspond to keys (not shown) on the hub of knife holder28, although it is understood that any other satisfactory engagement structure may be employed for ensuring that center pin52rotates with feed screw26. Accordingly, rotation of feed screw26functions to rotate both center pin52and knife assembly60, consisting of knife holder28and the knife inserts supported by the arms30a-30fof knife holder28. Bushing58and orifice plate32remain stationary, and rotatably support the end of center pin52.

As understood in the art, the head18is generally tubular and thus includes an axial bore68in which feed screw26is rotatably mounted. Bore68is typically provided with flutes70for controlling the flow of material through head18, i.e. for preventing material from simply rotating with feed screw and for providing a downstream flow path to prevent backpressure from pushing material back into hopper14. Also as is known, the dimension of flutes70may vary along the flute length to produce different effects. Head18may have an increased diameter at its downstream end. Flutes70may be primarily located adjacent or along this increased diameter area. Flutes70may be dimensioned to move material more efficiently across the transition area between the main body of head18and the increased diameter area of head18.

Referring toFIG. 6, the orifice plate32has an outer section72that includes a large number of relatively small grinding openings74, and an inner section76that includes a series of radially spaced collection passages78. The size of grinding openings74varies according to the type of material being ground and the desired end characteristics of the ground material. In accordance with known grinding principles, material within head18is forced toward orifice plate32by rotation of feed screw26and through openings74, with the knife inserts of rotating knife assembly60acting to sever the material against the inner grinding surface of orifice plate32prior to the material passing through openings74.

In some instances, pieces of hard material, such as bone or gristle, which may be too large to pass through grinding openings74, will be present along with the soft, useable material. These pieces, which are not cut by the action of the knife inserts against plate32, are pushed toward inner section76of plate32by the rotating action of knife assembly60, where the pieces of hard material can be removed from the primary ground material stream through collection passages78. Collection passages78are large relative to grinding openings74, and may be generally triangular, though it is understood that collection passages78may have any configuration as desired. Each of collection passages78may be provided with a ramped entryway80opening onto the surface of orifice plate32. Ramped entryways80may be provided on both sides of plate32, which may be double sided so as to extend the lifetime of use of plate32.

Inevitably, the hard material that passes through collection passages78carries with it a certain amount of usable soft material. This mixture of soft and hard material passes through collection passages78of orifice plate32to the separator assembly10, where it can be subjected to a secondary grinding and/or separation process to maximize ground material output. While it is advantageous to have separated as much usable soft material as possible from the hard material before it passes through the orifice plate32, nevertheless, in most instances, good, usable soft material is carried with the hard material through the collection passages78. In the past, conventional grinding machines have simply collected the hard material together with the soft material and treated them both as waste. The separator assembly10of the present invention, however, is designed to separate the usable soft material from the hard material that passes through the collection passages78of the orifice plate32, deliver the soft material to an appropriate outlet, and pass the hard material to a discharge or collection arrangement.

Referring toFIGS. 2 and 5, the separator assembly10includes a separator auger or screw62that is secured to, and rotates with, the center pin52. The separator assembly10also includes a separator chamber or tube64that defines a separator passage66that communicates with a collection tube or receptacle. Separator screw62is driven by feed screw26, and extends through the passage of separator chamber64and into and through discharge passage66. In addition, the separator assembly10includes a support84, which serves to support the outer ends of separator screw62and separator chamber64.

In the illustrated embodiment, the support84is in the form of a generally reverse C-shaped member including a pair of legs86that are connected together by an outer bridge section88. The inner ends of legs86are adapted to be secured to the structure of grinding head18, such as to the outwardly facing annular surface defined by mounting ring20. Representatively, the inner ends of legs86may be secured to mounting ring20by welding, although it is understood that any other satisfactory arrangement may be employed. Support84provides an open configuration downstream of orifice plate32, in that support84does not obstruct the discharge of material from the downstream surface of orifice plate32. In addition, while support84is shown as a reverse C-shaped member, it is understood that support84may have any other satisfactory configuration.

At the center of bridge section88, support84includes a support area shown generally at90. Support area90functions to engage and support the outer end of separator chamber64. In the illustrated embodiment, the support area90includes an annular lip92which defines a recess that faces orifice plate32. The end of separator chamber64has a reduced diameter area94defining a shoulder that is received within the recess defined by the lip92, which functions to securely engage and retain separator chamber64between support area90and orifice plate32. With this arrangement, separator chamber64is engaged to between orifice plate32and support area90in a manner that prevents axial movement of separator chamber64. Alternatively, the separator chamber64may be attached using a threaded arrangement.

The separator chamber64of separator assembly10is in the form of a generally elongated and tubular body that tapers or narrows from an intake end96at the downstream surface of orifice plate32to a discharge end98that interfaces with the support area90of support84as noted above. The separator passage66of separator chamber64is configured to allow the separator screw62to be passed through the separator chamber64and coupled to the feed screw26, so that the separator screw62rotates with the feed screw26. It is understood, however, that the separator screw62could be directly coupled to the feed screw26or coupled using a suitable coupler.

In the illustrated embodiment as best shown inFIGS. 2 and 5, the separator chamber64has a two-piece construction. It is understood, however, that the separator chamber64may also have a one-piece construction or maybe formed of any other number of components. As shown, the intake end96of separator chamber64has a generally conical shaped inlet that defines a frustoconical inlet volume82, which alternatively may be a series of individual inlet passages. The diameter of the intake end84is slightly greater than that of the inner section76of the orifice plate32so that the hard material that is passed through hard material collection passages78of the orifice plate32is received by the frustoconical inlet volume82of separator assembly10.

The intake end96of separator chamber64, in some embodiments, may be formed with spiral flutes83. Similarly, the discharge end98of separator chamber64, in some embodiments, may be provided with spiral flutes85. The spiral flutes83cooperate with separator screw62to provide positive engagement and downstream advancement of the material as it passes through inlet volume82at the upstream end of separator chamber64. Likewise, the spiral flutes85at the downstream end of separator chamber passage66provide positive engagement and downstream advancement of the material as it is discharged from separator chamber66.

The separator screw62includes helical pressure flights87that extend along its length. The diameter of the helical pressure flights87decreases from the intake end96to the discharge end98. In this regard, the diameters of the pressure flights87decrease along the length of the separator screw62to match the taper of the passage66defined by the wall of the separator chamber64, shown at97. A series of discharge perforations or openings99are formed in the wall97of the separator chamber64. The discharge openings99are formed in a perforation or hole zone of the separator chamber64located between the intake end96and the discharge end98, and are designed to pass soft material from the passage66of the separator chamber64to the exterior of the separator chamber64. The openings99are located between the spiral flutes83at the intake and96and the spiral flutes85at the discharge and98of separator chamber64. The separator chamber wall97defines a smooth inner surface within the perforation or whole zone of the separator chamber64.

The pressure flights87serve two primary functions. First, the flights87advance the mixture of soft and hard material from the collection passages78toward the discharge end98through the passage66of the separator chamber64. Second, the flights87force the mixture of soft and hard material against the inner surface of the wall97of the separator chamber64. As the separator screw62is rotated, flow of the mixture of soft and hard material through the passage66is restricted by the tapered inner surface of the wall97. This restriction functions to separate the soft material from the hard material, and the pressure within the passage66of the separator chamber64functions to force the separated soft material through the discharge openings99in the wall97. Moreover, since the separator chamber64is tapered, a shearing force applied to the mixture of soft and hard material by rotation of separator screw62remains relatively constant as it travels along the length of the separator chamber passage66. As a result, a continuous shearing force is applied to the hard material even as it is reduced in size as it is forced through passage66.

At the discharge and of the separator chamber64, the passage66defined by the separator chamber64communicates with an outlet passage100that extends through support area90of support84. In the illustrated embodiment, the outlet passage100is in the form of a constant diameter passage that extends from the downstream end of support area90to the upstream end, with the downstream end having a diameter that corresponds to the diameter of separator chamber passage66at discharge and98. It is understood, however, that outlet passage100may flare outwardly in an upstream-to-downstream direction so as to relieve pressure when the hard material is discharged from separator chamber passage66, to effectively release the hard material so that it can be propelled through outlet passage100to a collection arrangement, which may be a receptacle or a discharge conduit in a manner as is known.

Referring toFIGS. 2 and 5, centering pin52generally includes an inner section102that is configured to be received within the bore54in the end of feed screw26. In addition, centering pin52includes a knife mounting section104that is engaged within passage56in the hub section of knife holder28, and a bushing engagement section106that is received within the passage of bushing58, to rotatably support the centering and52relative to orifice plate32. In addition, the centering pin52includes a separator screw mounting section108adjacent bushing engagement section106, and an extension section110that extends outwardly from separator screw mounting section108. A transverse passage112extends through separator screw mounting section108.

Separator screw62has a generally hollow construction, defining an axial passage114extending throughout its length. At the inner or downstream end of separator screw62, passage114has a slightly enlarged diameter relative to the remainder of the length of the passage114, so as to define a recess116that extends into the inner end of separator screw62. At its outer or downstream end, passage112is formed with a series of internal threads118. In assembly, separator screw62is engaged with centering pin52such that extension section110of centering pin52is received within axial passage114of separator screw62. When separator screw62is fully engaged with centering pin52, separator screw mounting section108of centering pin52is received within recess116in the inner or downstream end of separator screw62. As shown inFIG. 5, there are close tolerances between the outside surfaces of separator screw mounting section108and extension section110and the respective facing surfaces of recess116and axial passage114, so that separator screw62is centered on the longitudinal axis of centering pin52.

Referring toFIGS. 3 and 4, the inner end of separator screw and62may be formed with a pair of transversely aligned slots120, which extend in a downstream direction from the inner or upstream end of separator screw62. To non-rotatably mount the separator screw62to centering pin52, a drive pin122may extend through transverse passage112in the separator screw mounting section108such that its ends are positioned within slots120. In this manner, separator screw62is mounted to drive pin52in a manner that ensures separator screw62rotates with centering pin52, while enabling axial movement of separator screw62relative to drive pin52by movement of slots120relative to drive pin122.

An adjustment arrangement124is engaged with the downstream end of separator screw62in order to enable adjustment in the axial position of separator screw62within passage66defined by separator chamber64. In this manner, the clearance between separator screw pressure flights87and the inner surface of separator chamber wall97can be adjusted to accommodate different material characteristics. Adjustment arrangement124includes a threaded adjustment member126, which may generally be in the form of a bolt having a head128and a shank130that is threaded throughout its length, in combination with a spacer or sleeve132and a locking member134, which may be in the form of a lock nut that is engageable with the threads of adjustment member126. As shown inFIGS. 5 and 8, sleeve132and shank130of adjustment member126extend through passage100in support area and90defined by support84, so that the outer end of sleeve132, locking member134and head128of adjustment member126are located outwardly of the downstream end of support area90. With this construction, sleeve132cooperates with passage100to form an annular discharge passage that is in communication with the downstream end of separator chamber passage66and extends through support area90, so as to enable hard material discharged from the downstream end of separator chamber passage66to flow through support area90for collection or discharge.

Locking member134is engaged with the threads of adjustment member shank130and is located toward head128. Shank130of adjustment member126extends through sleeve132and is engaged with internal threads118at the downstream end of axial passage114in separator screw62. In operation, the end of adjustment member shank130is engaged with the facing end of extension section110of centering pin52, and the inner end of sleeve132is engaged with the downstream end of separator screw62. Locking member134is rotatably advanced into engagement with the outer or downstream end of sleeve132, which thus prevents rotation of adjustment member126and locks the axial position of separator screw62. When it is desired to change the axial position of separator screw62so as to adjust the spacing between pressure fights87and the inner surface of separator chamber wall97, locking member134is moved toward head128so as to enable adjustment member126to be rotated. The user then rotates adjustment member126using head128, and engagement between separator screw threads118and the threads of shank130function to change the axial position of separator screw62. Relative axial movement between separator screw62and drive pin52is accommodated by slots120in the inner end of separator screw62. Once the desired axial position of separator screw62is attained, sleeve132is advanced inwardly so that its inner end is engaged with the end of separator screw62, and locking member134is again advanced into engagement with the outer end of sleeve132so as to secure the axial position of separator screw62.

FIG. 9is an enlarged view of the wall97of separator chamber64, showing the discharge perforations or openings99that extend through the wall97so as to establish communication between separator chamber passage66and the exterior of separator chamber64. The openings99as shown inFIG. 9have a constant diameter throughout the length of each opening99. In an alternative construction as shown inFIG. 10, the openings in the separator chamber wall97may be formed so as to have a reduced dimension inlet portion136and an expanded dimension outer portion138. The expanded dimension outer portion138may be formed with a transverse inner surface shown at140, which provides a relatively sudden transition between inlet portion136and outer portion138. In an alternative embodiment as shown inFIG. 11, an expanded dimension outer portion142may be formed with flared side walls which provide a more gradual transition between inlet portion136and the exterior surface of wall97. In both alternative embodiments, the expanded dimension outer portion provides pressure relief so as to facilitate the passage of material from passage66in separator chamber64through the openings or perforations in separator chamber wall97to the exterior of separator chamber64.

FIGS. 12-17disclose an alternate embodiment of the grinding arrangement16. Referring toFIGS. 12, 13A, and 13B,FIG. 12shows the grinder head18and mounting ring20, which may be similar to or the same as the components shown in the embodiment ofFIGS. 2 and 5. The mounting ring20may be supported by a ring lifter trolley1202, which supports a front-end of the grinding arrangement16at an attachment point1204. Rather than the tapered separator chamber64ofFIG. 2, this embodiment may include a cylindrical separator chamber1208or tubular structure having a cylindrical (parallel) sidewall1210that defines a constant diameter separator passage1304. The sidewall1210may include a plurality of sidewall apertures1216. The direction of product flow (a downsteam direction) is shown generally as1218.

FIGS. 13A and 13Bshow the mounting ring20further coupled to a support bridge1308, which includes a circular bridge ring1310and two or more support bridge ribs1312. Only a small cut-away portion of a support bridge rib1312is shown inFIG. 12for purposes of clarity. The support bridge1308performs a similar support function as the bridge section88and support84shown in the embodiment ofFIG. 2. The support bridge ribs1312may couple a bridge collar1336to the circular bridge ring1310. The circular bridge ring1310may have threads1314and a shoulder1316, which operatively couple the bridge ring1310with corresponding threads1224on the mounting ring20. Alternatively, the shoulder may be formed in mounting ring20.

The cylindrical separator chamber1208includes a flared input flange1320and a flared output flange1322, and both may be integrally formed with the cylindrical separator chamber1208. The flared input flange1320operatively mates with the bushing58so as to receive the food-product material via the collection passages78(and through corresponding apertures in the bushing58) in the orifice plate32(FIG. 5).

FIGS. 14 and 15illustrate some of the same components as shown inFIGS. 2, 5, and6, such as the center pin52, the knife holder28, the blades30a-30f, the orifice plate32, and the bushing58. Moreover, the embodiments ofFIGS. 12-17discloses differences from the embodiments ofFIGS. 2, 5, and 6, such as a constant diameter separator screw1410and the cylindrical separator chamber1208. Also included in this embodiment is a ring valve assembly1420having a ring valve1424, a ring valve carrier1426, and a ring lock1428. The ring valve assembly1420provides an adjustment to control an amount, and in some embodiments, the size, of the hard material processed through the separation chamber1208, as described below.

The ring valve1424has an internal conical portion1434(best seen inFIG. 17C) in communication with the nose portion1506of the separator screw1410, where the ring valve1424is in axial alignment with the separator screw1410. The ring valve carrier1426is configured to reciprocally displace the ring valve1424in an axial direction relative to the separator screw1410so as to vary a gap1440between the nose portion1506of the separator screw1410and the internal conical portion1434of the ring valve1424. The size of the gap1440determines an amount, and in some embodiments, a size of the hard material (along with some soft material) that may be passed toward a discharge outlet1450. In particular, the gap1440in the axial direction directly determines the amount of space between the inside diameter of the ring valve1423and the nose1506separator screw1410, and thus determines an amount, and in some embodiments, the size of hard matter, that can pass therethrough. The discharge outlet1450may be a pipe1802(seeFIG. 18) or other conduit operatively coupled to an end of the ring lock1428. The discharge outlet leads to a waste container (not shown).

As shown inFIGS. 13A and 131, the flared output flange1332includes one or more slots1330that communicate with corresponding pins1332in the fixed support collar1336. Further, the ring valve1424may be reciprocally and axially displaced relative to the fixed bridge support collar1336. The ring valve1424, the ring valve carrier1426, and the ring lock1428of the ring valve assembly1420are configured to adjust the axial displacement of the ring valve1424relative to the support collar1336. This, in turn, adjusts the distance or gap1440between the nose portion1506of the separator screw1410and the internal conical portion1434of the ring valve1424. Note that the separator screw1410may be driven by rotation of the center pin52(FIG. 14) as in the embodiments ofFIGS. 2, 5, and 6, and may be coupled to the center pin52using a spline fitting (seeFIG. 16G) or other known interlocking configuration.

As best shown inFIG. 15, the support collar1336includes a threaded portion1502. Further, the ring valve1424includes a threaded portion1510, the ring valve carrier1426includes a threaded portion1512, and the ring lock1428also includes a threaded portion1516. To adjust the gap1440, the threaded portion1512of the ring valve carrier1426, when rotated cooperates with the internal threaded portion1502of the support collar1336to axially displace the ring valve1424within the ring valve carrier1426. When the ring valve carrier1426is tightened against the support collar1336, a shoulder1518of the ring valve1424is urged against a corresponding shoulder1520of the ring valve carrier1426so as to urge the ring valve1424toward the separation chamber1208. Accordingly, rotation of the ring valve carrier1426in the axially direction may displace the ring valve1424within the collar1336. Once the desired gap is achieved, the ring lock1428is tightened using a wrench1526or other suitable tool to prevent further rotation of the ring valve carrier1426.

FIGS. 16A-16Hshow the separator screw1410in greater detail. The separator screw1410is disposed within the separator passage1304of the separator chamber1208, and includes a thread1604, also referred to as a non-tapering helical pressure flight. The separator screw1410is defined by constant major diameter1610and a constant minor diameter1612along its body portion1616. However, in some embodiments, the separator screw1410may have a variable minor diameter1612. Rotation of the separator screw1410within the separator chamber1208causes separation of soft material from the mixture of soft material and hard material, and forces most of the soft material through the apertures1216in the sidewall1210of the separator chamber1208, and advances the hard material that does not fit through the apertures1216in the downstream direction1218toward the discharge outlet1450.

The nose portion1506may include a plurality of angled ports or grooves1620. Preferably, the separator screw1410includes six grooves1620, however any suitable number of grooves1620may be included. Hard matter that is transported toward the nose1506of the separator screw1410within the separator chamber1208is partially crushed and advanced forwardly as the nose portion1506rotates proximate to the internal conical portion1434of the ring valve1424. The grooves1620in the nose portion1506and scalloped depressions1710in the valve ring1424assist in grinding down and reducing in size hard material that may be too large to pass through the discharge end1450. Note that approximately 99.8% of the soft material is collected through the apertures1215with only about 0.2% of the soft material inadvertently exiting toward the discharge end1450as waste along with the hard material. This percentage may vary slightly depending on the size of the gap1440.

FIGS. 17A-17Dshow the ring valve1424in greater detail.FIG. 17Cparticularly shows the internal conical portion1434of the ring valve1424, which preferably includes the eight equidistantly spaced scalloped depressions1710. However, any suitable number of scalloped depressions may be used. The scallop depressions1710, in conjunction with the nose1506of the separator screw1410and associated grooves1620, may regulate the amount or size of hard material passed out through a passageway formed in the ring valve1424, the ring valve carrier1426, and the ring lock1428.

The ring valve assembly1420provides a quick, easy, and accurate mechanism for manually adjusting the grinder16parameters, typically relating to a particular batch of food-product to process. Once set for a particular desired type of food processing, the amount of rejected material, and hence overall yield, is relatively fixed and constant.

FIG. 18Ais an exploded assembly view of pertinent components of the grinding arrangement16ofFIGS. 12-17, whileFIGS. 18B and 18Care side and end views, respectively of the grinding arrangement ofFIG. 18A.