Auger Outlet Extension

Abstract

An outlet extension is disclosed for an auger. The extension includes a forming core and a surrounding sleeve which are rigidly interconnected to the core of the auger. The forming core has a forming path defined in the surface thereof. The forming path is parallel to the axis of rotation of the forming core for the major portion of the length thereof and curved at the auger end thereof to form a continuation of the helix of the auger.

Parent Case Text

This application is a division of our copending application, Ser. No. 380,890, filed July 7, 1964 now U.S. Pat. No. 3,498,793, issued Mar. 3, 1970.

Description

PRODUCTS.

This invention relates to the art of producing food products high in protein and composed of edible protein fibers. More particularly, the invention concerns an auger outlet extension, such as may be used for manufacturing simulated meat products.

It is an object of the present invention to provide apparatus suitable for producing a fibrous food protein product which contains a substantial portion of protein and resembles a meat product.

A further object of the present invention is to provide a new and improved apparatus of sanitary design which can be operated on a continuous basis.

The invention contemplates a novel apparatus, which may include a mixer for combining a fibrous protein product with any additive and intimately intermixing the materials. The mixed materials are then discharged from the mixer into an auger where the material is heated to set a binder which is part of the additive and in which the fibers of the fibrous protein product are oriented in order to simulate the fiber orientation of the meat product. The auger is designed so that the product is compressed to remove air and to compact the fibrous product prior to discharge. At the discharge end of the auger an auger attachment is provided for controlling the discharge of the fibers in order to facilitate cutting or further processing of the processed product. A heating jacket may be utilized in connection with the auger wall in order to heat the combined materials and set the binder.

A complete understanding of the invention may be obtained from the following detailed description of an apparatus forming specific embodiments when read in conjunction with the drawing, in which;

FIG. 1 is a front view of an apparatus according to the present invention showing a mixer and an auger in partial cross section in relation to other elements of the apparatus,

FIG. 2 is a cross section view of the auger shown in FIG. 1 and showing the fibrous protein products in the auger,

FIG. 3 is a block diagram illustrating a process in which the present invention may be used,

FIG. 4 is a cross section view taken along lines 4-4 of FIG. 1,

FIG. 5 is an isometric view of a segment of the fibrous protein product prior to processing in the present invention,

FIG. 6 is an alternate embodiment of an auger which might be utilized in the apparatus shown in FIG. 1 and FIG. 2,

FIG. 7 is an alternate embodiment of an auger which might be used in the apparatus in FIGS. 1 and FIG. 2,

FIG. 8 is an end view of a section which might be attached to the auger illustrated in FIGS. 2, 6, and 7,

FIG. 9 is a segmented view partially in cross section of an alternate embodiment of FIG. 8 which may be attached to the end of the auger assembly as illustrated in FIG. 2,

FIG. 10 is an illustration of a problem which exists in the handling of fibrous protein material, and

FIG. 11 is a cross section view taken along lines 11-11 of FIG. 9.

The spun protein products can be produced using apparatus including the present invention. A wide variety of protein materials which are edible can be used in preparing the product. Representative of such materials are soybean, corn, peanuts, and pea proteins, as well as various animal proteins such as casein. The edible proteins spun into fibrous form may be prepared, for example, by first dispersing dry or water slurried protein in an alkaline medium. The amount of protein dispersed may range from about 10 to 30 percent by weight. A suitable alkaline medium is water containing an alkali metal hydroxide, that is about 5 to 10 percent by weight sodium hydroxide. The pH of the spinning solution can be varied to within relatively wide limits but may generally be in the range of 9 to 13.5. The viscosity and temperature of such dispersions is generally within the range of about 10,000 to 20,000 centipoises and about 25 to 45.degree.C., respectively. Viscosity, pH, temperature, and concentrations of alkaline metal hydroxide and protein will vary somewhat with the particular protein being dispersed. Also, dispersion may amount to a colloidal solution.

The spinning dispersion or dope is forced through a porous membrane such as a spinneret used in the production of rayon, and into a coagulating bath which is generally an acid and salt solution.

Individually spun filaments from the various spinnerettes are brought together in bundles or tows and stretched by pulling them from the coagulating bath over take up rolls. A variety of methods may be used to stretch the fibers composing the various tows. The stretching process alters textural characteristics by changing the diameter and strength of the individual fibers.

In such a process, the fibrous tow is first severed across its longitudinal axis into segments 12 such as that illustrated on the conveyor 11 of FIG. 1 in the drawing. The tow may be severed by conventional means and segments 12 deposited on the conveyor 11. The tow is cut into segments 12 in order that the segments may be processed to thoroughly impregnate the individual bundles of fibers with an additive which contains the individual constituents which provide the color, taste, smell and other characteristics of a meat product.

Next the segments 12 are combined with the additive which together with the fiber segments provide the physical characteristics of a product which resembles meat. An additive is formulated which contains constituents necessary to produce a particular type of meat products. Generally speaking, the additive will include a coloring agent to provide the meat color, a binder to bind the individual filaments of the fibrous protein product, a flavoring agent which will depend upon the meat to be simulated, a fat in order to increase the fat content of the finished product to a level normally associated with the meat involved, and other ingredients which might be utilized to enhance the stability of a product.

Binders are added to the fibrous protein product in order to bind the individual fibers together so that the fibrous texture of the product will resemble that of meat. The unbound fibers tend to separate when they are further processed, handled or cooked. When a binder is added, the mass of fibers appear to have the connective tissue normally associated with the connective tissue of ordinary meat.

Another major constituent of the additive is fat. All meat-type products have a certain quantity of fat associated with the protein of the meat product. This fat occurs in various flavors, concentrations, and physical forms depending upon the type of meat considered.

A number of vegetable oils both hydrogenated and unhydrogenated have been found to be useful. Examples of these are cottonseed oil, corn oil, soybean oil, coconut oil, and similar vegetable oils. Examples of animal fats may include lard, tallow, chicken fat, butter, fish oils, and various other animal and seafood fats. Other oils such as mineral oils, olive oil and the like might also be considered. It is to be pointed out here that the above fats are listed by way of example and not in terms of limiting the scope of the invention herein.

A number of other ingredients go into making up the additive. Examples of some of these additional constituents are skim milk solids which may be used as a filler and as a binder. Sugar, starch, monosodium glutamate as a flavor enhancer, hydrolyzed protein as a flavoring agent, spices, onions, salt, dried egg whites, wheat gluten, garlic, white pepper, and onion powder, and other ingredients which will produce the final flavor and characteristics of the meat being simulated. The number and type of ingredients is only limited in part by the characteristics which are desired in the end product considering such things as the final use to which the product will be placed such as a chilled product or a cooked product, a dry product or a wet product, the type of meat to be simulated, the period of stability desired in the product and similar factors.

The segments 12 are next combined with the additive containing the above-described constituents. The combining may take place by simply pouring the additive together with the segment 12 into a suitable container for containing the mass. At this point the combined segments and additive are agitated in some manner in order to impregnate the fibers with the additives. This impregnation step is illustrated by block 13 in the block diagram shown in FIG. 3 of the drawings.

At this point, the viscous mass containing the fibers and the impregnating additive does not resemble a meat product for several reasons. First the mass is in a sense viscous. Secondly, the fibers are not aligned in any fashion in a manner normally recognizable in meat. Further, the fibers do not have the compact consistency normally associated with meat. Accordingly, the viscous mass is next worked or treated in order to impart many of the physical characteristics associated with meat to the fibrous protein product. The mass containing the randomly aligned fibers is accordingly drawn out and worked so that the fibers become aligned in a somewhat uniform fashion. Meat normally has a fiber alignment characteristic of the muscle involved in the meat cut. Accordingly, the mass may be layed out in a thin stream in order to achieve some degree of fiber alignment. An apparatus which might also be utilized for accomplishing the fiber alignment is illustrated in the drawings and is described hereinafter. An auger is utilized for this purpose and tends to align the fibers as the material travels from the feed end of the auger to the discharge end thereof. This augering action tends to align the fibers and simulate the fibered texture and characteristics of meat.

As illustrated in box 14 of the block diagram shown in FIG. 3, the alignment and compression of the fibers may take place at the same time. A squeezing action is applied to the mass of viscous material so that the fibers are forced together or into contact with each other thus substantially achieving the compactness of the fiber bundle of a meat product. The compression may be accomplished in varying degrees in order to simulate the various meat products which may be reproduced. For instance, a beef-type product will normally have more compact fiber structure than might be expected in a fish-type product. Accordingly, application of more or less pressure to the viscous fibrous mass is utilized in order to accomplish the end result desired. This compression can be accomplished by simply squeezing the fibers together by mechanical means or by hand. The requirement is that the fibers be compacted. Again an example of an apparatus which might be utilized for this purpose is illustrated in the drawings and will be described as noted.

If a binder is properly chosen, one which will coagulate and set under compressive action, the binder will coagulate and agglutinate or bind the individual fibers together in somewhat the same manner that the connective tissue in a muscle fiber bind the various fibers of a meat product together. This binding function of the binding constituent in the additive thus imparts firmness to the product. Thus with the fibers aligned in substantially the same manner as that in the meat product and with the fibers bound together by a suitable binder such as one of the types listed, the fibrous protein product takes on the consistency of a meat product. If the proper combination of ingredients is chosen, and processed in this manner, the resultant product will have a toughness and resistance to disintegration which is characteristic of meat.

Depending upon the particular characteristics of the binder utilized, the heat or whatever coagulating agent is utilized, may be applied prior to the compression of the product as well as during the compression of the product. One of the essential results which is to be achieved is compaction of the fibrous material so that the individual fibers of the mass will be securely bound together. The binder also serves one other function and that involves the "locking" of the various ingredients or constituents of the additive in position, within the fibrous segments 12. The coagulated binder acts as an agent for locking the distributed ingredients of the additive about the fibers so that the thorough distribution of the additive achieved by the agitation remains constant after the product has been processed to a finished product. This is essential of course in order to insure uniformity of the product and a sustained high quality of the product. The binder also prevents the flavoring agents and coloring material from leaching out of the finished product.

At this point in the process, the product is an unbroken coagulated mass of simulated meat product which has the essential characteristics of a meat product. The unbroken mass may now be further processed to enhance the characteristics of the product if desired. For instance, if hamburger is desired as the finished product, a further processing step of grinding may be necessary to bring the simulated meat product to the consistency of hamburger. If a seafood, fish, or fowl-type product is to be simulated, the product may be diced, cubed or sliced in order to simulate the usual characteristics of these products. If a ham product is to be simulated, slicing of the product or for that matter, cubing the product may be desirable.

Since the product described at this point is essentially a moist product, having a quantity of water trapped by the coagulated binder, a further step may be taken to make the product marketable. This step involves drying the product so that it may be packed in ordinary packages and stored without refrigeration. The drying brings the moisture content of the product to about 2 percent to about 8 percent by weight. Preferably, the product is dried to a range of from about 4 percent to about 5 percent by weight. Thus a hamburger product may be dried so that the resulting product is granular in form. It has been found that this granular product can be stored without refrigeration and is easily rehydrated by simply heating the product in the presence of moisture. The drying illustrated by box 17 in the block diagram of FIG. 3 may be accomplished by any number of well-known methods of drying granular material or cubed material.

Most of these steps described above in connection with processing the fibrous protein product from a raw fiber to a finished simulated meat can be accomplished by readily available equipment or can be accomplished by simple hand operated means. Also, one embodiment of a novel and preferred apparatus in which the process of the invention may be accomplished is set forth in the attached drawings.

After the segments 12 have been cut by conventional cutting means, they are deposited as noted above on the conveyor belt 11. This conveyor belt carries the segments to an inlet 18 of a mixer 19. Housing 21 of mixer 19 is an enclosed tank or reservoir for containing combined segments 12 and additive. The additive is combined with the segments 12 at the inlet 18 flow from tanks 22 and 23. Tank 22 contains a discharge 24 for introducing fat into inlet 18 of mixer 19. The discharge 24 contains a valve 26 for controlling the rate of flow of fat from the tank 22 so that a precise amount of fat may be added to the segments 12 depending on end characteristics desired in the finished simulated meat product. A serum is mixed and consists essentially of all the other previously described ingredients. The serum is stored in tank 23. From this tank 23, the serum flows through discharge 27 and is combined with the segments 12 and the fat from the tank 22. A combined fat and serum make up the additive as the term is used in this specification. (If proper emulsifiers are used, the fat can be premixed with the serum ingredients.) A valve 28 is utilized to control the quantity of serum flowing from the serum tank 23. As with the fat, a control for regulating the amount of serum introduced into combination with the segments is necessary in order to arrive at a desired end characteristics in the simulated meat product. The fat and serum are essentially in a liquid form and therefore the housing 21 must be of such a nature that the liquid can be contained.

Refer now to FIG. 4 of the drawings where the mixer 19 is shown. The mixer 19 has two agitators 29 mounted side by side in the housing 21. These agitators 29 each contain a shaft 31 with radially extending paddles 32 along the length of the shaft. Each shaft 31 is mounted at either end of the housing 21 by bearing supports 30 and 33. The agitators are driven through a sprocket and chain drive which is connected to motor 34. The motor 34 drives sprocket 36 through a gear system 37. The sprocket 36 and sprocket 38, which is connected to the drive shaft 29 are interconnected by a chain 41. The sprocket 38 is connected to a gear system 39 which transmits the power from the motor 34 to both of the shafts 31 thus rotating the agitators 29. The gear systems 37 and 39 may be utilized to operate the agitators at any speed desired. Also, manipulation of the gear systems can accomplish rotation of the agitators in clockwise or counterclockwise directions depending upon the degree and kind of agitation desired for the combined segments and additive.

The mixer thoroughly and violently agitates the combined segments and additive so that the fibrous bundles or segments 12 develop an appearance similar to liquid saturated balls of cotton. This agitating action by the paddles 32 results in thoroughly impregnating the fibrous segments with the additive so that the resulting mass as noted previously, appears to be a rather viscous mass containing fibers. The fibers thus saturated are randomly aligned due to the intense agitation to which they have been subjected. The mixer 19 may be slightly tilted toward the discharge end 42 or the paddles 32 may be slanted so that the mass of material moves from the inlet 18 toward the outlet 42 of the mixer 19. The fibrous mass of material is discharged directly into the inlet 43 of an auger cooker generally designated by the number 44. The fibrous mass of material 46 enters the opening 43 where it encounters the flights 47 of an auger generally designated by the numeral 48.

The auger 48 (FIG. 2) is driven through a drive system by a motor 49. (See also FIG. 1.) This motor 49 can be directly connected to the core 51 of the auger 48 as shown in FIG. 2 or it may be connected to the auger 48 through a sprocket and gear chain system as illustrated in FIG. 1 of the drawings. In the FIG. 1 system, the motor 49 is connected to a shaft 52 through a sprocket 53, a chain 54 and a sprocket 56. This sprocket system is in turn driven by motor 49 through a gear reducer 57. The gear reducer permits control of the speed of the auger 48. The auger 48 is mounted within the auger housing 58 by mounting the auger 48 on a suitable bearing block 61. The auger 48 may be cantilever mounted such as that shown in the FIG. 2 so that the discharge end 59 is not mounted on a bearing block to disrupt the flow of material along the flights 47 of the auger. If, however, the auger 48 is too large to be cantilever mounted on a bearing 61 as shown in FIG. 2, then a bearing block and bearing may be attached to the discharge end 59 to support the auger 48. These are mere mechanical manipulations within the skill of the art.

The mass of viscous fiber material engages the flight 47 at the auger input 62 and is conveyed by rotation of the auger 48 from the input end 62 to the discharge end 59. The fibrous mass enters the auger 48 as a mass of material having the appearance of saturated fibrous cotton with random alignment of the fibers in the mass. During the movement of the fibrous mass from the input end 62 to the output end 59, the auger tends to align the fibers. This alignment apparently comes from the plug-type movement of the material as it is moved along the auger flights 47. Experience has shown that the fibrous mass tends to be transformed from a mass of randomly aligned fibers at the input end 62 to a mass having a noticeable fiber alignment at the discharge end 59.

The fibrous mass is compressed between the auger flights 47, the core 51, and the wall of the housing 58 as it moves along the length of the auger 48. This compression forces the individual fibers of the mass together thereby compacting the fibrous material removing excess air from between the fibers and enhancing its meatlike characteristics.

If the fibrous mass introduced into the opening 49 contains an additive having a eat coagulable binder such as egg albumin in a preferred embodiment, a hot water jacket 63 is placed about the auger housing 58 so that hot water or steam may be introduced through inlet 64 to contact the outer walls of the auger housing 58. (This heat unit might also be electric or the like.) This heating medium warms the walls of auger housing 58 and heats the mass between the flights 47 to a temperature sufficient to coagulate the binder. Accordingly, as the fibrous mass moves along the length of the auger 48 to the discharge end 59, the binder is coagulated at a controlled rate depending upon the temperatures applied to the auger housing 58 and is completely coagulated when the product reaches the discharge end 59. The binder coagulates and traps the ingredients of the additive throughout the fibrous mass for uniform distribution and locks these ingredients in place throughout the cross section of the resulting product. Further, the heat coagulable binder in this case binds the fibers together so that the finished product discharged from the discharge end 59 has the firm consistency of a meat product. The compression of the fibrous material during the coagulation of the binder forces the individual fibers of the mass closer together so that the binder effectively binds the individual fibers together in addition to trapping the ingredients of the additive in the overall mass of material. The resulting product discharged at 59 is a plug of material 66 which has a recognizable fiber alignment which simulates that of meat and which has a texture, physical appearance, and other characteristics of a meat product. The hot water which enters through inlet 64 is discharged through outlet 67 so that a complete circulation of heating water or steam is accomplished throughout the jacket 63. The temperature supplied to the walls were noted previously in connection with the description of the process involved. The hot water jacket 63 may have several compartments 65 so that a separate water supply at inputs 64, 70, 75 and 85 can be used to heat the wall of the housing 58. See FIG. 1. This permits temperature control along the length of the auger. The valves 80 individually control the rate of flow of steam and/or hot water to the respective compartments. The auger core 51 may also be made hollow (see FIG. 4) so that a heat unit 55 can be inserted This additional heat unit permits more effective control of the temperatures within the housing 58.

Since the finished product 63 emerges as a long plug of simulated meat product, the product does not resemble the physically recognizable cuts of meat ordinarily encountered in a butcher shop. A cutter 68 is attached to the end of the auger housing 58 so that blades 69 inserted within the cutter 68 will cut the plug of material 66 into chunks sufficiently small to be further processed. The auger flights 47 simply force the plug of material 66 against the sharp knives 69 thus severing the plug of material 66 at various points. The chunks of material are then discharged for further processing.

Ordinarily one associates a difference in texture and compactness with the different meat products. This difference in texture and firmness can often be measured in terms of compactness or toughness of the meat product. This characteristic can be achieved in part by compressing the fibrous mass to a greater degree than possibly by a simple auger such as 48 where the core 51 is straight and the auger flights are uniform depth and pitch. An auger, typical of those on which the present invention may be mounted, is disclosed in FIG. 6. Auger 71 has a core 72 which tapers from the input end 73 to the output end 74. In other words the depth of the individual flight 76 becomes less toward the output end 74 of the auger 71. A further change in auger 71 is the change in the pitch of the flight 76. The pitch is decreased toward the output end 74. This combination of decreased toward the output end 74. This combination of decreased depth of flight and decreased pitch of the flights result in a reduced volume into which the fibrous mass is compressed with respect to the wall of the auger housing 58. The result of this reduced volume of course results in an increase in the compression applied to the fibrous mass as it moves from the input end 73 to the discharge end 74. An auger such as this has been successfully utilized for the production of red meat-type products.

Another embodiment of an auger which might be utilized in the apparatus disclosed in FIG. 1 is the auger 77 illustrated in FIG. 7 of the drawings. Auger 77 contains flights 78 which have a varying pitch. The core 79 of the extruder 77 is also varied in diameter so that the depth of the flight 78 varies from the input end to the output end thus producing the squeezing or compressing action achieved in the auger 71 of FIG. 6. Auger 77, however, contains an additional section 81 connected to the output end of the auger for manipulating the fibrous plug of material at the output end 82. In the auger illustrated in FIGS. 2 and 6, the plug of material leaves the augers and forms a helix in substantially the form of a coil spring. The plug of material from such an auger moves parallel to the central axis of the coil and consequently there may be some problem in handling the material. For instance, in further processing, it may be desired to cut the finished fibrous protein product in a certain manner but to cut it along the length of the plug rather than cross section the plug. Therefore, section 81 provides a means for aligning the plug of material so that the plug of material ultimately emerges from the auger 77 in a continuous straight stream of material. Section 81 contains a pair of channels 83 and 86 which are a continuation of the space between flights 78. These channels are essentially extensions of the helical path between flights 78. A plug of material which arrives at point 84 is separated by the extension 86 so that a portion of the plug follows channel 83 and a second portion of the plug moves along channel 86. Channels 83 and 86 gradually change direction until the channels are parallel to the central axis of the auger 77 and thus material travelling along the length of the channels 83 and 86 emerge from the auger 77 parallel to the axis thereof and travelling in a forward direction along the length of the plug. This permits cutting the plug of material across the length of the plug. More than two channels may be utilized and such an auger with three channels has been used with success.

The section 81 illustrated in FIG. 7 shows two channels 83 and 87 which are formed from a single flight extruder. Refer now to FIG. 8 for a similar section 88 which is an extension of a double flight extruder 89. In such an extruder 89, no point 86 necessary to separate the plug of material leaving the auger flight. In this case two plugs of material, one in each of two separate channels 91 and 92 simply move along the longitudinal axis of the auger 88 without separating into two parts. It is to be noted at this point that a number of channels 91 which might be utilized in an end section 88 may be varied from 1 to several such channels.

Since the end channels which align the product along the central axis along the auger results in a product having the fiber alignment substantially parallel to the central axis of the core of the auger, a special problem arises. The problem is illustrated in FIG. 10 of the drawings where the fibrous product 93 is shown in cross section. The core 94 of the auger or end section 81 such as that shown in FIG. 7, is surrounded by a sleeve 96. This sleeve normally would be an extension of the wall of the housing 58 shown in FIG. 2 and is stationary. Since the core 94 is rotating in the clockwise direction and the individual fibers of the product 93 are parallel to the central axis as noted of the core 94, the relative movement between the auger core 94 and the stationary housing 96 forces a few fibers 97 between the moving surfaces of the core 94 and the sleeve 96 into the space 98. This material 97 produces clogging of the working mechanisms and produces a damaged and unsanitary finished product. The damage occurs because the fibers 99 next the inside wall of the sleeve 96 tend to cling to the sleeve and are not properly carried with channel 101. This condition occurs in the end section referred to and discussed in FIGS. 7 and 8 of the drawings because of the realignment of the plug of fibrous product. Accordingly, the present invention provides a solution to this problem and is illustrated in FIGS. 9 and 11 of the drawings. The housing of the auger 102 contains a flange 103 at the output end. Within this flange a sleeve 104 is fitted by a moving connection such as a bearing 106. The sleeve 104 is rigidly connected by a setscrew 107 to the forming core 108. Thus it will be noted that as the auger 109 rotates, the end section 111 also moves but the sleeve 104 moves with the forming core 108 thus no fibers will slide in the space 98 illustrated in FIG. 10 and clog the outlet end of the auger. This result is achieved because at a place where the plug is moving in a helical fashion within the housing no clogging problem occurs since the fibers engage the stationary wall along their length. The clogging only occurs when the fibers simultaneously move parallel to their own axis and engage a stationary wall while the fibers are also moving about the core of the auger in a channel 101. The effect of the mechanism in FIG. 9 is to remove the later relative movement between the fibers and a containing wall 104. The end section illustrated in FIG. 9 may be connected to the auger 109 by a bolt 112 as illustrated in FIG. 9 or it may be an integral part of the auger as illustrated in FIG. 7 of the drawings.

It is to be understood that the examples, embodiments and variations are merely illustrative of the invention and numerous modifications will occur to those skilled in the art which fall within the scope of the invention.

Claims

We claim:

1. An outlet extension for an auger and housing which comprises a forming core rigidly connected to the core of said auger, said forming core having a forming path in the surface of said forming core and parallel for a major portion of the length of said forming core to the axis of rotation of said forming core, said forming path being curved at the auger end of said forming core to form a continuation of the helix of said auger, a sleeve surrounding said forming core and rigidly connected to said forming core, said sleeve having an inside diameter equal to the inside diameter of the housing surrounding said auger, and bearing means interconnecting said sleeve and housing.

2. An outlet extension for an auger and housing which comprises a forming core rigidly connected to the core of said auger, said forming core having at least two forming paths in the surface of said forming core each parallel for a major portion of the length of said forming core to the axis of rotation of said forming core, each of said paths being curved at the auger end of said forming core to form a continuation of the helix of said auger, a sleeve surrounding said forming core and rigidly connected to said forming core, said sleeve having an inside diameter equal to the inside diameter of the housing surrounding said auger and bearing means interconnecting said sleeve and housing.