Abstract:
A rotary knife includes a handle, a rotatable annular blade, an expandle blade housing, and a housing support. The blade housing is movable relative to the handle between a blade-securing condition, in which the blade housing securely supports the blade for rotational operation, and a relatively expanded blade-releasing condition, in which the blade housing permits removal and installation of the blade relative to the blade housing. The housing support is coupled to the handle and supports the housing in the blade-securing and blade-releasing conditions. The support and housing include interengaging surfaces that contact one another in the blade-securing condition, with at least one of the interengaging surfaces including an applied high-friction coating.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The present invention relates generally to powered knives, such as those commonly used in meat processing plants. More specifically, embodiments of the present invention concern a rotary knife with a blade housing having a high-grip connection. 
         [0003]    2. Discussion of Prior Art 
         [0004]    Powered rotary knives that are used in the meat processing industry for dressing an animal carcass are known in the art. The process of dressing the carcass normally involves the removal of meat and fat from various bones as well as cutting various bones. Powered rotary knives enable workers to perform this process with great efficiency. 
         [0005]    Turning to  FIGS. 1-4 , one such prior art rotary knife K includes a handle H, a blade housing BH, an annular blade B, a pinion housing PH, and a pinion cover C. The blade B is rotatably supported by the blade housing BH. As is customary, the blade housing BH is releasably clamped between the pinion housing PH and pinion cover C. The blade housing BH and pinion cover C each present grooved surfaces S that frictionally engage one another when the blade housing BH is clamped into position. The frictional engagement between grooved surfaces S restricts relative movement between the blade housing BH and the pinion cover C when the blade housing BH is secured. Reliable securement of the blade housing BH is important to maintain uniform and smooth rotating engagement between the blade B and blade housing BH. Movement of the blade housing BH relative to pinion cover C out of the secured position can cause excessive wear and/or malfunction of the blade housing BH, blade B, or both. 
         [0006]    It has been found that prior art rotary knives suffer from certain deficiencies. For instance, the high-speed rotational movement of the annular blade, which is ideal for quickly and efficiently processing meat, causes the cutting edge of the annular blade to quickly become dull and require frequent sharpening or replacement. As a result, conventional rotary knives suffer from problems associated with knife maintenance. For example, the grooved surfaces S can become worn over time so as to lose frictional engagement (e.g., due to repeated knife assembly and disassembly for blade sharpening and replacement and/or due to the blade housing being too loosely or firmly clamped into the operating position). Thus, because the illustrated frictional connection provided by grooved surfaces S between the blade housing BH and pinion cover C is prone to wear, such wear can result in unintended relative movement between the blade housing BH and pinion cover C that causes excessive wear and/or malfunction of the blade housing BH, blade B, or both. 
       SUMMARY 
       [0007]    The following brief summary is provided to indicate the nature of the subject matter disclosed herein. While certain aspects of the present invention are described below, the summary is not intended to limit the scope of the present invention. 
         [0008]    Embodiments of the present invention provide a rotary knife that does not suffer from the problems and limitations of the prior art knives set forth above. 
         [0009]    A first aspect of the present invention concerns a rotary knife that broadly includes a handle, a rotatable annular blade, an expandable blade housing, and a housing support. The expandable blade housing is configured to removably support the blade. The blade housing is movable relative to the handle between a blade-securing condition, in which the blade housing securely supports the blade for rotational operation, and a relatively expanded blade-releasing condition, in which the blade housing permits removal and installation of the blade relative to the blade housing. The housing support is coupled to the handle and supports the housing on the handle in the blade-securing and blade-releasing conditions. The support and housing include interengaging surfaces that contact one another when the housing is in the blade-securing condition, with at least one of the interengaging surfaces including an applied high-friction coating so as to enhance frictional engagement between the housing and support and thereby restrict inadvertent expansion of the housing to the blade-releasing condition. 
         [0010]    A second aspect of the present invention concerns a pinion cover for a rotary knife, wherein the knife includes a rotatable annular blade removably supported by an expandable housing that is at least in part clamped between the pinion cover and a pinion housing member to releasably retain the housing in a blade-securing condition. The pinion cover broadly includes a generally arcuately shaped body. The body presents a radially outwardly facing clamping face that is configured to be in an opposing relationship with the pinion housing. The clamping face is configured to contact at least a portion of the housing. The clamping face includes an applied high-friction coating so as to enhance frictional engagement with the at least a portion of the housing and thereby restrict inadvertent expansion of the housing out of the blade-releasing condition. 
         [0011]    A third aspect of the present invention concerns a method of refurbishing a rotary knife, wherein the knife includes a rotatable annular blade removably supported by an expandable housing element that is at least in part clamped between clamping elements to releasably retain the housing element in a blade-securing condition, with each clamping element cooperating with the housing element to define interengaging surfaces that contact one another when the housing element is in the blade-securing condition. The knife refurbishing method broadly includes the steps of preparing at least one of the elements to receive a high-friction coating thereon; and applying a high-friction coating to the at least one of the elements such that the high-friction coating at least partly defines the corresponding interengaging surface, with the high-friction coating serving to enhance frictional engagement between the elements and thereby restrict inadvertent expansion of the housing out of the blade-securing condition. 
         [0012]    Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0013]    Preferred embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein: 
           [0014]      FIG. 1  is an upper perspective of a prior art rotary knife including a handle, a blade housing, an annular blade rotatably mounted in the blade housing, and a housing support that secures the blade housing to the handle, with the housing support including a pinion housing and a pinion cover; 
           [0015]      FIG. 2  is a fragmentary cross section of the prior art rotary knife taken along line  2 - 2  in  FIG. 1 , showing a radially inwardly facing engagement surface of the blade housing and a radially outwardly facing engagement surface of the pinion cover, with the engagement surfaces each presenting a plurality of spaced apart grooves to enhance frictional engagement between the surfaces; 
           [0016]      FIG. 3  is an enlarged fragmentary perspective of the pinion cover shown in  FIGS. 1 and 2 , showing the grooved engagement surface of the pinion cover; 
           [0017]      FIG. 4  is an enlarged fragmentary perspective of the blade housing shown in  FIGS. 1 and 2 , showing the grooved engagement surface of the blade housing; 
           [0018]      FIG. 5  is an upper perspective of a rotary knife constructed in accordance with a preferred embodiment of the present invention, with the rotary knife including a handle, a blade housing, an annular blade rotatably mounted in the blade housing, and a housing support that secures the blade housing to the handle, with the housing support including a pinion housing and a pinion cover; 
           [0019]      FIG. 6  is a fragmentary cross section taken along line  6 - 6  in  FIG. 5 , showing a radially inwardly facing surface of the blade housing and a radially outwardly facing surface of the pinion cover each including a high-friction coating applied to the underlying substrate, with the surfaces being in frictional engagement with one another; 
           [0020]      FIG. 7  is an exploded fragmentary perspective of the rotary knife shown in  FIGS. 5 and 6 ; 
           [0021]      FIG. 8  is an exploded fragmentary perspective of the rotary knife similar to  FIG. 7  but taken from an opposite side of the knife; 
           [0022]      FIG. 9  is an enlarged fragmentary perspective of the pinion cover shown in  FIGS. 5-8 , showing the high-friction coating of the pinion cover; and 
           [0023]      FIG. 10  is an enlarged fragmentary perspective of the blade housing shown in  FIGS. 5-8 , showing the high-friction coating of the blade housing. 
       
    
    
       [0024]    The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the preferred embodiment. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    Turning initially to  FIG. 5 , a rotary knife  20  is constructed in accordance with a preferred embodiment of the present invention. The illustrated rotary knife  20  is particularly well suited for use in meat processing facilities, although other knife applications are entirely within the ambit of the present invention. The illustrated rotary knife  20  is preferably pneumatically powered by a pressurized air source (not shown), e.g., an air compressor. However, the principles of the present invention are equally applicable where the rotary knife is driven by alternative external power sources, such as sources that transmit power through hydraulic power or electrical power. The rotary knife  20  broadly includes a handle  22 , an expandable split blade housing  24 , a rotating annular blade  26 , a pinion housing  27 , and a pinion cover  28 . 
         [0026]    The handle  22  includes a grip housing  30 . The grip housing  30  has a generally cylindrical shape and extends between a proximal connector end  34  and a distal end  36 . The proximal end  34  is configured for quick connection to a pneumatic supply (not shown) or alternative power source. The grip housing  30  further presents an internal passage that houses a pneumatic motor (not shown). 
         [0027]    Turning to  FIGS. 5-10 , the pinion housing  27 , pinion cover  28 , and fasteners preferably cooperatively provide a housing support that supports the blade housing  24  relative to the handle  22 . In particular, the pinion housing  27  and pinion cover  28  serve as clamping components that clamp and thereby support the blade housing  24 . However, as will be described in greater detail, the illustrated housing support could be alternatively configured without departing from the scope of the present invention. 
         [0028]    The pinion housing  27  is preferably fixed to the grip housing  30  at the distal end  36  and includes an arcuate clamping surface  38 , a pinion-receiving socket  40 , and holes  42 . The arcuate clamping surface  38  defines a laterally extending rib  44  for positioning the blade housing  24 , as will be discussed (see  FIG. 7 ). The socket  40  is sized to receive and permit rotation of a drive pinion  46 . The drive pinion  46  is interconnected with and is rotatably powered by the pneumatic motor. 
         [0029]    The expandable split blade housing  24  is substantially unitary and can be flexed so as to expand and contract between a blade-securing condition and a relative expanded blade-releasing condition. The blade housing  24  is annular and includes adjacent ends  48 , an annular ring  50 , and a flange  52 . The blade housing  24  preferably presents a pinion-receiving opening  54  defined between the ends  48 . The blade housing  24  also preferably presents arcuate inner and outer housing surfaces  56 , 58 , with the outer housing surface  58  facing in a radially outward direction and the inner housing surface  56  facing oppositely to the outer housing surface  58  in a radially inward direction. The arcuate outer housing surface  58  defines a circumferential outer housing groove  60  that generally extends laterally along the flange  52 . The outer housing surface  58  also presents axial slots  62  (see  FIG. 8 ). The inner housing surface  44  defines circumferential rib segments  64  and a circumferential inner housing groove  66  (see  FIGS. 7 and 8 ). The inner housing groove  66  serves as a race for rotatably supporting the blade  26  as will be discussed. Between the ends  48 , the inner housing groove  66  extends substantially along the perimeter of the ring  50 . 
         [0030]    While the illustrated blade housing  24  preferably includes the single inner housing groove  66 , it is consistent with the principles of the present invention for the blade housing  24  to include an alternative groove configuration for rotatably supporting the blade  26 , e.g., an alternative number of grooves or an alternative groove shape. Preferred features of such alternative blade housing and groove constructions are disclosed in U.S. Pat. No. 8,037,611, issued Oct. 18, 2011, entitled ROTARY KNIFE WITH BLADE BUSHING, and U.S. application Ser. No. 13/283,324, filed Oct. 27, 2011, entitled ROTARY KNIFE WITH MECHANISM FOR CONTROLLING BLADE HOUSING, both of which are incorporated in their entirety by reference herein. 
         [0031]    The handle  22 , blade housing  24 , pinion housing  27 , and pinion cover  28  are preferably manufactured from a tempered steel to resist oxidation and corrosion within the adverse environment of a slaughterhouse. However, the principles of the present invention are equally applicable where the handle  22 , blade housing  24 , pinion housing  27 , and pinion cover  28  include other metallic or non-metallic materials such as brass, aluminum, or stainless steel. 
         [0032]    In the illustrated embodiment, the blade housing  24  also preferably includes a high-friction coating  68  applied to the substrate housing material along the flange  52 . Preferably, the inner housing surface  56  of the blade housing  24  includes the coating  68 . Also, the coating  68  is preferably a single material layer that is applied in sections adjacent to each end  48 . As defined herein, a high-friction coating refers to a coating applied to the surface of a substrate (e.g., where the coating is adhered to the substrate surface) so that when the combined substrate and coating frictionally engages another surface, the resulting coefficient of friction is greater than the coefficient of friction associated with frictional engagement between the substrate surface and the another surface. As will be discussed, the coating  68  is most preferably designed to frictionally engage another coating applied to the pinion cover  28 . 
         [0033]    It is also within the scope of the present invention where the blade housing  24  includes, either entirely or partly, an outermost material layer for other purposes, such as corrosion resistance, aesthetic qualities, or other performance requirements. For instance, the blade housing  24  could have a layer of brass, aluminum, or stainless steel that is suitable for surface-to-surface engagement with the blade  26 . In this manner, such an outermost layer, whether coated, adhered, or otherwise secured onto the base material, may provide an optimal surface for low-friction bearing engagement with the blade  26 . 
         [0034]    The blade housing  24  is attached to the pinion housing  27  by arranging the outer housing surface  58  in engagement with the clamping surface  38  so that the ribs  44  are positioned within the outer housing groove  60  and the drive pinion  46  is aligned with the pinion-receiving opening  54 . As will be discussed, the pinion cover  28  and fasteners  70  secure the blade housing  24  to the pinion housing  27  and permit adjustable clamping of the blade housing  24  between the pinion housing  27  and pinion cover  28 . 
         [0035]    Turning to  FIGS. 7 and 8 , the annular blade  26  is preferably unitary and is substantially continuous around its circumference. The blade  26  includes a blade wall  72  and a ring gear  74  extending from the blade wall  72  for mating with the drive pinion  46 . The blade wall  72  presents a sharp cutting edge  76  and an arcuate outer blade groove  78 . The blade  26  is preferably rotatably mounted in the blade housing  24  by positioning the rib segments  64  in sliding engagement within the outer blade groove  78 . 
         [0036]    If desired, the blade  26  may be alternatively configured to include other types of edges. For example, instead of the sharp edge  76 , the blade  26  could alternatively include an abrasive edge (e.g., with a surface that is gritted), a bristled edge, or a brush-type shredding edge. Similar to the blade housing  24 , it is consistent with the principles of the present invention for the blade  26  to include an alternative groove configuration, such as an alternative number of grooves or an alternative groove shape. 
         [0037]    The blade  26  is preferably manufactured from tempered steel. However, similar to the handle  22 , blade housing  24 , pinion housing  27 , and pinion cover  28 , the principles of the present invention are applicable where the blade  26  includes other metallic or non-metallic materials, such as brass, aluminum, or stainless steel. Alternatively, the blade  26 , either entirely or partly, may include an outermost layer of brass, aluminum, or stainless steel that is suitable for surface-to-surface engagement with the blade housing  24 . In this manner, such an outermost layer, whether coated, adhered, or otherwise secured onto the base material, may provide an optimal surface for low-friction bearing engagement. However, the outermost layer may be included for other purposes, such as corrosion resistance, aesthetic qualities, or other performance requirements. It will also be appreciated that the blade  26  could be mounted within the blade housing  24  using an annular bushing to restrict wear of the blade  26  and/or blade housing  24 . Embodiments of a rotary knife with preferred features of an annular blade bushing are disclosed in the above-incorporated &#39;611 patent and &#39;324 application. 
         [0038]    The pinion cover  28  preferably includes a unitary body with a curved wall  80  and internally-threaded bosses  82  that are integrally formed with the wall  80 . The wall  80  includes a pair of oppositely positioned tab ends  84 . The pinion cover  28  also preferably includes a high-friction coating  86 . The illustrated coating  86  is preferably a single material layer applied continuously from one tab end  84  to the other tab end  84 . Thus, the pinion cover  28  presents a clamping surface  88  that faces in a radially outward direction and includes the coating  86 . 
         [0039]    The coatings  68 , 86  are preferably formed with a liquid epoxy and discrete aluminum oxide particles interspersed within the epoxy to provide a gritted coating surface. However, it is also within the scope of the present invention where an alternative coating is used, e.g., to provide a suitable coefficient of friction. For instance, an alternative synthetic resin could be used to form the coatings  68 , 86 . Also, discrete grit particles made from an alternative material, such as silicon carbide or diamond, could be employed with the epoxy. For some aspects of the present invention, the coatings  68 , 86  could also be devoid of grit particles. 
         [0040]    Again, the illustrated coatings  68 , 86  each preferably comprise a single layer of the combined epoxy and particles. However, it is within the ambit of the present invention where multiple layers of epoxy and particles are applied to form the coatings  68 , 86 . For instance, it may be necessary to adjust the thickness dimensions T 1 ,T 2  of the coatings  68 , 86 , e.g., where the thickness dimension T is increased to compensate for wear of the corresponding substrate (see  FIG. 6 ). While the thickness dimensions T 1 ,T 2  are preferably substantially the same, the coatings  68 , 86  could have different thicknesses without departing from the scope of the present invention. 
         [0041]    The coatings  68 , 86  are preferably applied to the respective underlying substrate. Prior to application of coatings  68 , 86 , one or more steps are preferably required to prepare the substrate surface (e.g., so that adhesion is maximized between the substrate and coating). Preferably, the substrate surface is prepared by cleaning the surface (e.g., with a solvent), then abrading the surface, and then cleaning the abraded surface again. Preparation of the surface might also involve complete or partial removal of any previous coating layers. However, preparation of the substrate surface could involve just one of the foregoing steps. Furthermore, it will be appreciated that other preparatory steps could be required before coating application. The process of abrading the substrate surface is preferably done using sandpaper with a grit size that ranges from about one hundred (100) grit to about four hundred (400) grit. However, the substrate surface could be roughened by techniques other than abrasion, e.g., by etching the substrate surface, without departing from the scope of the present invention. 
         [0042]    Application of coatings  68 , 86  is preferably done manually, although the principles of the present invention are applicable where a machine is employed to apply the coatings. For application of a single coating layer, the coating material is initially mixed. In particular, grit particles and epoxy are preferably mixed to provided the illustrated coating material. The mixed coating material is then applied to the prepared substrate surface in a coating layer. The applied coating layer is then allowed to set prior to use of the single coating layer and substrate. 
         [0043]    To form the coatings  68 , 86  by applying multiple coating layers, coating material is mixed, a first coating layer is then applied to the prepared substrate surface, and the first applied coating layer is then allowed to set. Each subsequent coating layer is applied to the previous coating layer after the previous coating layer has set. Each subsequent coating layer is then allowed to set prior to application of another coating layer or use of the combined coating and underlying substrate. 
         [0044]    Application of the high-friction coatings to the corresponding substrate is preferably intended to be performed as part of a knife refurbishment process, as will be described further. However, it is also within the scope of the present invention where the coatings are applied as part of the original knife component manufacturing process. 
         [0045]    The pinion housing  27  and pinion cover  28  are shiftable relative to each other and preferably used to removably attach and support the blade housing  24  relative to the handle  22 . In particular, fasteners  70  preferably extend through holes  42  in the pinion housing  27 , along openings  90  presented by the flange  52 , and are threaded into the threaded holes presented by the bosses  82  so that the blade housing  24  is clamped between the pinion cover  28  and the pinion housing  27 . With the pinion housing  27  and pinion cover  28  holding the blade housing  24  in clamping engagement, further tightening of the fasteners  70  serves to increase the gripping force applied to the blade housing  24  by the pinion housing  27  and pinion cover  28 . 
         [0046]    Similarly, with the pinion housing  27  and pinion cover  28  in clamping engagement, loosening of the fasteners  70  serves to decrease the applied gripping force. Thus, the secured blade housing  24  can be disassembled from the knife  20  by loosening the fasteners  70  and shifting the pinion cover  28  away from the pinion housing  27 . Such disengagement of the pinion housing  27  and pinion cover  28  permits removal of the blade housing  24  therefrom. Subsequently, the removed blade housing  24  can be selectively expanded from the blade-securing condition to the blade-releasing condition to permit removal of blade  26  from the blade housing  24 . 
         [0047]    Blade housing removal may accompany one or more of various knife maintenance procedures. For instance, blade housing removal may be followed by application of the illustrated coatings  68 , 86 . Alternatively, blade housing removal may be followed by sharpening of the removed blade, followed by reinstallation of the sharpened blade. Yet further, blade housing removal could be followed by installation of another blade, such as an entirely new annular blade. 
         [0048]    In any event, the blade to be installed in the knife  20  can be rotatably mounted in the expanded blade housing  24  following any application and setting of coatings  68 , 86 . The blade is inserted by expanding the blade housing from the blade-securing condition to the blade-releasing condition, positioning the blade in rotatable engagement with the inner housing surface  56 , and returning the blade housing  24  to the blade-securing condition. After blade insertion, the blade housing  24  can be secured between the pinion housing  27  and pinion cover  28 . Securement of the blade housing  24  includes the steps of positioning the flange  52  between the pinion housing  27  and pinion cover  28 , with the outer housing surface  58  adjacent the clamping surface  38  and the inner housing surface  56  adjacent the clamping surface  88 . The fasteners  70  are then inserted through the pinion housing  27 , threaded into the pinion cover  28 , and tightened so as to clamp the blade housing  24  in place. 
         [0049]    With the blade housing  24  secured relative to the handle  22 , the clamping surface  38  of pinion housing  27  is preferably opposed to and interengaged with the outer housing surface  58 . Also, the clamping surface  88  of pinion cover  28  is preferably opposed to and interengaged with the inner housing surface  56 . Furthermore, the clamping surfaces  38 , 88  are preferably opposed to each other. 
         [0050]    In this manner, the fasteners  70  hold the pinion housing  27  and pinion cover  28  in clamping engagement with the blade housing  24 . However, for some aspects of the present invention, the pinion cover  28  could be constructed so as not to be used to secure the blade housing  24 . For instance, the blade housing  24  could simply be secured to the pinion housing  27  with fasteners. 
         [0051]    Preferably, the coatings  68 , 86  frictionally engage one another when the pinion housing  27  and pinion cover  28  are clamped to and secure the blade housing  24 . Also, the pinion cover  28  preferably substantially covers the drive pinion  46  while permitting intermeshing engagement between the drive pinion  46  and the blade  26 . 
         [0052]    While the knife  20  is preferably constructed so that the pinion cover  28  is separate from the blade housing  24 , it is also within the scope of the present invention where the pinion cover  28  is provided as part of the blade housing  24  and/or pinion housing  27 . 
         [0053]    The illustrated knife  20  preferably includes both of the illustrated coatings  68 , 86  so that the coatings  68 , 86  cooperatively provide a high coefficient of friction between the pinion cover  28  and blade housing  24 . However, for some aspects of the present invention, the knife  20  could be provided with only one of the coatings  68 , 86 . For example, the knife  20  could have only the coating  86  on the pinion cover  28 , with the coating  86  being in frictional engagement with the substrate of the flange  52 . 
         [0054]    It is also within the ambit of the present invention where the coatings  68 , 86  are alternatively positioned to frictionally hold the blade housing  24  in the desired position. For instance, the coatings  68 , 86  could be applied to the pinion housing  27  to define at least part of the curved clamping surface  38  and to the blade housing  24  to define at least part of the outer housing surface  58 . In this manner, the coatings  68 , 86  could provide direct frictional engagement between the blade housing  24  and the pinion housing  27 . Also, the clamping surfaces  38 , 88  and housing surfaces  56 , 58  could all include coatings to provide additional frictional engagement. 
         [0055]    In operation, the knife  20  is preferably maintained by periodic refurbishment of interengaging surfaces of the pinion housing  27  and the blade housing  24 . It is to be understood that knife refurbishment can involve not only re-coating of a surface that has previously been provided with the coating material but also newly applying the coating material to a new or used knife component. For example, the blade housing BH and pinion cover C of the knife K shown in  FIGS. 1-4  may have one or more coating layers applied thereto once the grooved surfaces S have become worn. In any case, surface refurbishment is initiated by removing the blade housing  24  and blade  26  from the pinion housing  27 . Removal of the blade housing  24  and blade  26  preferably exposes the clamping surfaces  38 , 88  and the inner and outer housing surfaces  56 , 58 . Consequently, blade housing removal also serves to expose surfaces for application of coatings  68 , 86 . 
         [0056]    Prior to the coating application, knife refurbishment continues by preparing the underlying substrate surfaces of the blade housing  24  and pinion cover  28 . As described, such preparation preferably involves a desired sequence of cleaning and abrading the surface. Coating material is then mixed and prepared. The mixed coating material is then applied to the prepared surfaces to form a coating layer. The coating layer is then allowed to set. Once the coatings are set, the blade housing  24  is secured to the handle  22  by the pinion housing  27  and the pinion cover  28  with fasteners  70 . 
         [0057]    The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. 
         [0058]    The inventor hereby states his intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.