Abstract:
A rotary cutter assembly has a spindle journaled by a bearing assembly. A cutter mounting member is fixed to the spindle for rotation therewith and has an outermost annular skirt that flares radially outwardly and downwardly to a lowermost peripheral edge. The bearing housing that supports the bearing has an upstanding rib that surrounds the lower peripheral edge of the mounting member and projects upwardly beyond the same for a short distance. This overlapping relationship between the rib and the lower skirt periphery prevents the ingress of foreign materials into close proximity with the bearing assembly to thereby prolong its useful life.

Description:
TECHNICAL FIELD 
   The present invention relates to the field of rotary cutters such as the type used in farm equipment for mowing standing crop materials. More particularly, it relates to a way of inhibiting the migration of stringy materials and foreign matter deeply into the interior of such cutter assemblies where they can cause damage and premature component failure. 
   BACKGROUND AND SUMMARY 
   High speed rotary cutters are well known in the art. However, one nagging problem with such cutters is that foreign materials such as baling twine, wire or stringy crop materials can sometimes migrate into the bearing cavity of the cutters and wrap around the rotating spindle. This can cause damage to seals associated with the bearings and lead to premature bearing failure. Even if the materials do not reach the bearing cavity, they can still become wrapped tightly under the cutter mounting member of the assembly and build up to such a point that they generate an inordinate amount of heat, which can also result in premature bearing failure. 
   Accordingly, an important object of the present invention is to provide a rotary cutter assembly that inhibits the migration of deleterious materials into the immediate vicinity of the bearing assembly of the unit. It is also an important object of the invention to provide a cutter design that encourages foreign materials that would otherwise migrate to the center of the assembly to instead wrap around more exterior portions of the assembly in places less likely to cause damage and where they can be more easily removed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top front isometric view of a rotary cutter bed of the type typically utilized in connection with windrowers, mower-conditioners and other mowing equipment and which may incorporate the principles of the present invention; 
       FIG. 2  is an enlarged, fragmentary, exploded isometric view of one of the rotary cutter assemblies of the cutter bed in  FIG. 1 , illustrating details of construction; 
       FIG. 3  is an enlarged, transverse cross-sectional view through one of the cutter assemblies taken substantially along line  3 - 3  of  FIG. 1 ; 
       FIG. 3   a  is a further enlarged, fragmentary view of the assembly in  FIG. 3  illustrating the manner in which a construction in accordance with the present invention inhibits the migration of foreign materials into the center of the assembly; 
       FIG. 4  is a transverse cross-sectional view of a prior art cutter assembly; and 
       FIG. 4   a  is an enlarged, fragmentary cross-sectional view of the prior art assembly of  FIG. 4  illustrating the way in which foreign materials migrate into the center of the assembly. 
   

   DETAILED DESCRIPTION 
   The present invention is susceptible of embodiment in many different forms. While the drawings illustrate and the specification describes certain preferred embodiments of the invention, it is to be understood that such disclosure is by way of example only. There is no intent to limit the principles of the present invention to the particular disclosed embodiments. 
   The rotary cutter bed  10  illustrated in  FIG. 1  has a series of individual cutter assemblies  12  that are essentially identical to one another. Among other things, each assembly  12  includes an elliptical-shaped disc  14  that rotates at relatively high speeds about an upright axis and which carries a pair of flail-type cutter blades  16  at opposite ends thereof for impacting and severing standing crop materials as the disc rotates. Cutter assemblies  12  are timed relative to one another so that blades  16  of adjacent assemblies do not strike one another, even though their paths of travel overlap. In the illustrated embodiment, the two outboard assemblies  12  at opposite ends of bed  10  rotate in the same direction, i.e., generally toward the center of the cutter bed, while the six remaining inboard assemblies  12  rotate in mutually opposite directions, i.e., in oppositely rotating pairs. As will be seen, this arrangement can obviously be varied without impacting the principles of the present invention. 
   As illustrated particularly in  FIGS. 2 ,  3  and  3   a , each cutter assembly  12  further includes an upright, rotatable spindle  18  that defines the axis of rotation of disc  14 . Spindle  18  is journaled by a bearing assembly  20  that is captured within an upright bore  22  in the central hub  24  of a stationary bearing housing  26 . Bearing housing  26  rests upon an upwardly projecting rim  28  around a hole  30  in a generally flat, hollow gear case  32  of the cutter bed  10 . In the illustrated embodiment, gear case  32  is comprised of a series of interconnected modules, but this construction can vary without affecting the principles of the present invention. 
   It will also be seen that in the illustrated embodiment, spindle  18  is driven by an integrally joined spur gear  34  within the open compartment  36  of gear case  32  below hole  30 . Spur gear  34  has a pair of idlers  38  (only one being shown) engaged therewith on opposite sides of spindle  18  for the purpose of receiving driving power from an adjacent module and transferring it along the gear train to the next adjacent module. Numerous variations of this type of gear train may also be utilized without affecting the principles of the present invention including, for example, utilizing shafts and intermeshing bevel gears within gear case  32 . The axes of rotation of idlers  38  are slightly behind spindle  18  and are represented in  FIG. 2  by the hexagonal sockets  40  and  42  associated with bearing assemblies for the idlers  38 . 
   As illustrated in  FIG. 2  spindle  18  includes a splined portion  44  as illustrated in Fig. that mates with the internally splined bore  46  of a generally conical cutter mounting member  48  so that member  48  rotates with spindle  18 . Mounting member  48  includes a central hub  50  through which bore  46  passes, the hub  50  being disposed in stacked relation to the hub  24  of bearing housing  26 . Of course, member  48  rotates relative to bearing housing  26 , which is secured to gear case  32  by a plurality of bolt assemblies  52  about the periphery of housing  26 . A nut  54  and washer  56  on an uppermost externally threaded portion  58  of spindle  18  are utilized to secure mounting member  48  in place on spindle  18 . 
   Projecting radially outwardly from hub  50  of mounting member  48  is a horizontal, annular, flat flange  60 . At the radially outermost extremity of flange  60 , an annular skirt  62  is affixed thereto and extends downwardly and outwardly therefrom. The outermost and lowermost extremity of skirt  62  defines a peripheral edge  64  of mounting member  48 . Skirt  62  thus presents a radially outer face  66  of member  48  that slopes upwardly and inwardly from peripheral edge  64 , giving member  48  its overall conical appearance as illustrated in  FIG. 2 . Due to the skirted construction of member  48 , the underside of flange  60  and radially inside of skirt  62  define an annular void region  68  above bearing housing  26 . 
   Bearing housing  26  also is provided with an annular, generally flat, horizontally extending flange  70  that projects outwardly from hub  24 . In the top surface of flange  70 , an upstanding, annular rib  72  is defined in surrounding relationship to the peripheral edge  64  of mounting member  48 . Rib  72  projects upwardly beyond peripheral edge  64  and cooperates with the hub  24  to define a continuous, annular recess  74  in the top face of flange  70  that receives skirt edge  64 . As illustrated particularly in  FIG. 3   a , rib  72  is generally triangular in cross-sectional configuration so as to present an outer, upwardly and inwardly sloping face  76 . Thus, face  76  of rib  72  and face  66  of skirt  62  slope generally upwardly and inwardly in the same direction, although in the illustrated embodiment, face  76  of rib  72  has a slightly lower slope angle than face  66  of skirt  62  such that face  76  slopes generally toward face  66 . In a most preferred embodiment of the invention, rib  72  is a continuous rib about the periphery of mounting member  48 , although it is within the principles of the present invention to have such rib discontinuous as well. 
   The upper surface of flange  60  of mounting member  48  is provided with four drilled and tapped holes  78 . Such holes  78  threadably receive four bolts  80  to detachably secure disc  14  to mounting member  48 . Corresponding holes  82  in disc  14  register with holes  78  in mounting member  48  to allow the shanks of bolts  80  to pass through disc  14  and into threaded engagement with mounting member  48 . A larger centrally disposed hole  84  in disc  14  receives the upper portion of hub  50  when disc  14  is in place on mounting member  48 . A domed cap  86  may be fastened to disc  14  in overlying relationship to large hole  84  and the upper end of spindle  18  and nut  54  for covering such structures. Cap  86  is provided with four bolt holes  88  that align with holes  78  and  82  so that bolts  80  may be utilized to secure cap  86  in place. 
   As illustrated especially in  FIG. 3   a , when disc  14  is rotating at high speeds, stringy crop materials, twine and other foreign matter can slip beneath disc  14  as illustrated by the arrow  90  into an outer annular void region  92  defined between the underside of disc  14 , the top of bearing housing  26  outboard of mounting member  48 , and skirt  66  of mounting member  48 . However, once the materials are within the outer void region  92 , they can travel no further into the interior of the cutter assembly due to the barriers presented by rib  72  and skirt  62 . Although the materials can wrap around skirt  62 , such materials tend to migrate toward the portion of least diameter of skirt  62 , i.e., the top of skirt  62  adjacent flange  60 , rather than work their way down and under peripheral edge  64  into the inner void region  68  closer to bearing assembly  20 . There is no relative rotation between mounting member  48  and disc  14 ; thus, materials that accumulate up in the “corner” between member  48  and disc  14  are not subjected to friction and heat buildup from high speed, relatively moving surfaces. This keeps bearing assembly  20  protected against the abrasive effects of the wrapping materials and prevents the build-up of excessive heat within interior void region  68  which might otherwise adversely affect the useful life of bearing assembly  20 . 
   In the event it becomes necessary or desirable to remove accumulating materials from within the outer void region  92 , this can be readily accomplished by simply removing bolts  80 , pulling off cap  86  and discs  14 , and removing the accumulated materials from around the outside of mounting member  48 . Thereafter, disc  14  and cover  86  are quickly and easily reinstalled and bolts  80  are tightened down to return the components to their normal operating conditions. 
   Note that it is not necessary to remove mounting member  48  because materials should not be accumulating within the inner void region  68 . Thus, there is no need to loosen and remove the main nut  54  on spindle  18  and lift off mounting member  48 . This is a great time-saver and also avoids the risk of failing to re-establish proper timing relationship in the cutter assembly when mounting member  48  is replaced on spindle  18  and nut  54  is tightened down. 
     FIGS. 4 and 4   a  illustrate a prior art construction which allows debris and other foreign materials to enter deeply into the cutter assembly and cause damage to the bearing assembly or premature failure thereof. In these views, the prior art cutter assembly is designated by the numeral  100  and includes many of the same components as cutter assembly  12 , but in different configurations. For example, in prior art cutter assembly  100 , the spindle  102  is journaled by a bearing assembly  104  that is in turn retained by a bearing housing  106  secured to the gear case  108 . A cutter mounting member  110  is secured to spindle  102  for rotation therewith relative to bearing housing  106 , and a disc  112  is secured to mounting member  110  for rotation therewith. 
   Mounting member  110  has a radially outermost, downwardly projecting, annular skirt  114  that presents a lowermost peripheral edge  116  spaced only a short distance above bearing housing  106  so as to provide running clearance. Skirt  114  has a vertical, non-tapering outer face  118 . An inner annular void region  120  is defined above the flange of bearing housing  106  and inboard of skirt  114 , while an outer annual void region  122  is defined under the outer portion of disc  112  and outboard of skirt  118  above bearing housing flange  106 . 
   In this prior art cutter assembly  100 , foreign materials can slip under discs  112  as illustrated by the arrow  124 . Instead of remaining in the outer void region  122 , however, such materials have a tendency to work their way under the peripheral edge  116  of skirt  118  and into the more sensitive inner void region  120 . Once within inner void region  120 , the materials can work their way through the interface between mounting member  110  and the hub of bearing housing  106  to enter the bearing cavity where the bearing assembly  104  is located. Once in that region, the materials can destroy the seal the bearing assembly, allowing the grease to escape and causing the bearing to fail in that manner. Even if the materials do not fully find their way into the bearing cavity, their build-up within inner void region  120  can result in the generation of excessive heat in that area caused by the frictional interengagement of rotating mounting member  110  and the trapped foreign matter, leading to premature bearing failure for that reason. This bearing failure then necessitates complete disassembly and rework of the cutter assembly. This is a very undesirable and frustrating circumstance, also causing significant loss of time during the repair and rebuild operations. 
   However, with the present invention as noted earlier, the foreign materials have no opportunity to enter the inner void region  68 . Instead, the most that can happen is that they are guided upwardly by the sloping outer face  66  of mounting member  48  to migrate toward the top corner of the outer void region  92 , where they accumulate beneath the underside of disc  14 . Such materials can then be quickly and easily removed by simply pulling off the disc  14  and removing the materials. 
   The inventor(s) hereby state(s) his/their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his/their invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.