Abstract:
A double disk C-spring standard assembly utilizes bearings mounted to a simple carrier plate. The plate is connected to the lower end of a single C-spring oriented in the fore-and-aft direction. Bearing assembly mounting holes in the plate define the necessary gang angles. Compact disk blade hub assemblies facilitate side-by-side mounting of the center bearing assemblies.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to bearings for agricultural disk blades and, more specifically, to a disk blade assembly for working the soil at the juncture of angled disk gangs. 
   BACKGROUND OF THE INVENTION 
   Recently developed combination tillage implements have employed disk blades with individually mounted bearing blade assemblies which are able to run in wetter fall soil conditions. Many of the combination tillage implements include bulky C-spring standards supporting angled gang tubes which meet in at the implement center. The C-springs are angled toward one another, and mounting requirements for the springs force the center blades to be more widely spaced than desired. The wide spacing of the center blades results in an inadequate cut of the soil at the center of the machine. The center disk spacing problem typically is overcome either by employing a special standard bearing assembly to mount two disk blades or by utilizing an intermediate short gang tube in the middle to carry the two disk assemblies. Both solutions require a costly weldment or assembly. 
   The disk blade bearings are subjected to high loads in a severe environment. Bearing seal failure leading to premature bearing failure has been an ongoing problem. For years, the main attempt at a solution to the problem has been the utilization of a grease fitting with frequent scheduled greasing to flush contaminates out of the bearing. For most disk gang bearing applications, frequent greasing has been a generally acceptable practice since each bearing normally supports from three to six blades and the grease fittings are reasonably accessible. However, the frequent greasing is time-consuming and reduces the productivity of the implement. Machines with individually mounted blades create two new problems relative to the grease method of flushing the bearings. First, wetter field conditions are harder on the seals. Mud packs into the seal area and ultimately works into the bearing to cause permanent damage to the seals. 
   To overcome the mud problem, the frequency of required re-greasing to flush the contaminates and prevent bearing failure has to be increased. The individually mounted blade bearing assemblies result in more bearings to carry the same number of blades as a disk gang. The combination of more grease fittings to grease and an increased maintenance frequency results in a difficult time-consuming maintenance chore. In addition, the mounting requirements for the C-springs force the center blades to be more widely spaced than desired adjacent the juncture of the angled tubes supporting the C-springs results in an uneven tillage pattern near the center of the machine. 
   SUMMARY OF THE INVENTION 
   A double disk C-spring standard utilizes the bearing assemblies mounted to a simple carrier plate. Bearing assembly mounting holes in the plate define the necessary gang angles. Compact disk blade hub assemblies facilitate side-by-side mounting of the center bearing assemblies. The plate is connected to the lower end of a single C-spring oriented in the fore-and-aft direction. The C-spring is supported from the implement frame utilizing front to rear tie plate and two-hole straps both added to the outsides of gang tube half connecting plates. 
   The mounting system is compact and economical. Bearing assemblies identical to those used on the remainder of the machine can be used on double C-spring standard. An even soil cut is obtained at the juncture of angled gang tubes without need for costly and cumbersome special two disk bearing assemblies or an intermediate short gang tube. A simple fore-and-aft C-spring orientation provides necessary support for two center cutting disks. The spring section does not need to be heavier than on a single disk system since the primary force is thrust load and the double disk C-spring actually sees less resultant load since the thrust loads of the two mounted disks are substantially equal and opposite and therefore balance out. 
   The bearing mounting facilitates supporting two disk closely together at the tool-receiving end of the C-spring. If desired, the disks arrangement can be configured to be symmetrical about an upright fore-and-aft extending plane with each bearing housing terminating near the plane so that the housings do not interfere with each other. 
   These and other objects, features and advantages of the present invention will become apparent from the detailed description below in view of the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a portion of an agricultural implement having disk blade assemblies supported from converging gang tubes. 
       FIG. 2  is an enlarged sectional view of one of the disk blade assemblies shown in  FIG. 1   
       FIG. 3  is an exploded view of the disk blade assembly of FIG.  2 . 
       FIG. 4  is a lower front perspective view showing the single standard double disk structure adjacent the central gang tube connection in FIG.  1 . 
       FIG. 5  is a bottom view of the disk structure of FIG.  4 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , therein is shown a portion of an agricultural tillage implement  10  such as a mulch ripper or other implement having a frame  12  supporting disk blade assemblies indicated generally at  14 ,  15  and  16 . The implement frame  12  includes angled gang tubes  20  and  22  forming opposite halves centrally connected by gang tube plate bracket structure  25 . Standard bracket structures  36 ,  38  and  40  connect the disk blade assemblies  14 ,  15  and  16  to the tubes  20  and  22  to generally define disk gangs  44  and  46  angled with respect to a direction transverse to the forward direction (F). 
   The disk blade assemblies  14 ,  15  and  16  are shown with identical disk bearing hub assemblies  50  ( FIGS. 2 and 3 ) which are shown and described in copending and commonly assigned U.S. application Ser. No. 10/437,756 filed concurrently herewith and entitled Disk Blade Bearing Hub Assembly. The hub assemblies  50  are connected to the lower tool-receiving ends of curved shanks or C-springs  54  and  55  in either concave right (assemblies  14 ) or concave left (assemblies  15 ) configuration. The hub assemblies  50  are reversible on the C-springs, and therefore a single hub configuration may be utilized for all the assemblies  14 ,  15  and  16 . The hub assembly for the blade assemblies  14  will be described in detail below, and it is to be understood that the hub configuration for the remaining assemblies  15  and  16  is generally identical. Although shown with a cushion standards  58 , the blade assemblies  14 , 15  and  16  can also be utilized with a rigid standard construction. 
   The uppermost end of the C-spring  54  is connected to the tube  20  by the clamp  34  ( FIG. 1 ) in generally a fore-and-aft configuration with the C-spring opening in the rearward direction. The lower tool-receiving end of the C-spring approaches a horizontal orientation directly below the clamp  34  and is apertured at fore-and-aft spaced locations to receive a pair of mounting bolts  58  which connect the hub assembly  50  to the C-spring. 
   The hub assembly  50  includes a main housing  60  having a generally cylindrically shaped outer surface  62  with a first or blade-side end  64  and a second or innermost end  66 . The upper portion of the main housing  60  includes forward and aft projecting apertured lugs  68  symmetrically arranged relative to the housing for receiving the mounting bolts  58  which secure the housing to the underside of the tool-receiving end of the C-spring  54 . 
   The housing  60  includes a central stepped bore  70  extending from the first side  64  through to the second side  66 . The bore is machined with the diameter of each section of the bore decreasing in diameter from the side  64  to the side  66 . A factory sealed and preset double row tapered roller bearing  76 , such as a Timken® UNIPAC™ bearing, is seated in a central machined section  80  of the bore  70  and secured therein by a snap ring  82  (FIG.  2 ). A seal such as a triple lip seal  86  and a seal cup  88  are located in a machined outer bore section  90 . The seal  86  is offset axially outwardly of the outermost extremity of the tapered roller bearing  76  to define a grease-receiving cavity or area  92  adjacent the step between the sections  80  and  90  which provides an intermediate grease layer barrier reducing contaminants reaching the bearing  76 . An annular plastic or Teflon® seal protector  100  is located at the opening in the side  64 . An outer grease cavity or area  102  is defined between the seal protector and the seal  86 . 
   A forged alloy steel spindle  110  having a stepped cylindrical surface extending into the bore  70  includes a machined innermost section  116  extending through the inner race of the bearing  76 . The circumference of the spindle  110  increases at section  118  to extend radially outwardly around the outer end of the bearing  76  adjacent the snap ring  82  and supports the body or base of the seal  86 . An outer section  120 , having a diameter slightly greater than that of the section  118 , extends to the end of the bore  70  in contact with the seal protector  100 . 
   An enlarged outermost end of the spindle  110  includes a housing overlap portion  120  projecting radially outwardly of the first side  64  of the housing  60 . The overlap portion includes a protective lip  124  extending in the axial direction towards the inner end of the spindle  110  at a location adjacent the outer surface  62  of the first side of the housing. A blade-receiving non-circular projection  126  projects axially outwardly from a central portion of the outermost end of the spindle  110  to support a conventional concave outwardly disk blade  128  via mating aperture  129 . 
   A standard grade 8 bolt  130  extends through a washer  132 , a blade clamp casting  134  and a central bore  136  in the spindle  110 . The threaded end of the bolt  130  projects axially through the bore  136  beyond the innermost end of the bearing  76  but is protectively maintained within the bore  70  of the housing  62 . A washer  140  is inserted over the threaded end, and a nut  142  is threaded onto the bolt to urge the washer against the end of the spindle  110  and against the inner race of the bearing  76 . The headed end of the bolt  130  draws the blade clamp casting  134  against the blade  128  to sandwich the blade between the casting and the outermost end of the spindle  110 . The bolt  130 , blade  128 , spindle  110  and inner race of the bearing  76  are constrained to rotate together about a disk blade axis  148 . 
   The bearing  76  supports the spindle  110  and blade  128  for rotation about the axis  148 . The lip  124  of the hub overlap portion deflects dirt and debris away from the seal protector  100  and prevents wrapping by stringy material such as vines and twine. The seal protector  100  keeps dirt and debris from pushing directly into external seal lips of the multiple lip seal  86 . A layer of grease in the cavity  102  provides another barrier which protects the seal  86  from dirt and debris. The lip seal  86  provides positive sealing and is backed up by a grease layer barrier in the cavity  92 . The hub overlap, plastic seal protector, multiple lip seal and grease barriers protect the seal of the bearing  76 . The above-described bearing structure with protective arrangement has been shown to increase average bearing life many times over that of conventional disk bearing structures. 
   The back side of the bearing hub is also positively sealed using an O-ring  152  and dust cap  154 . As best seen in  FIG. 2 , the cap  154  is recessed within the innermost end  66  of the housing  62  and protects the threads of the bolt  130  and the nut  142 . The structure eliminates a large dust cap on the blade side of the assembly that would otherwise hinder scouring of the blade  128 . The overall width of the bearing assembly is reduced to facilitate close side-by-side disk blade mounting near the center of a machine adjacent the intersection of gang tube halves as shown at  15  in FIG.  1 . 
   To facilitate easy removal of the bearing  76  from the housing  62 , the bore  70  includes inner ledge structure  160  near the innermost end  66  for facilitating support of a bearing removal tool within the housing. A screw-threaded insert (not shown) may be positioned against the ledge structure  160  and a bolt threaded into the bore  70 . The bolt will contact and force the spindle  110  outwardly as the bolt is threaded into the bore. Thereafter, the procedure is repeated with an enlarged end placed on the bolt which contacts and forces the bearing  76  outwardly. 
   As shown in  FIGS. 1 ,  4  and  5 , the cushioned assembly  15  includes a C-spring oriented generally in the fore-and-aft direction and having an upper mounting end connected to the gang tube plate bracket structure  25  which secures the gang tubes  20  and  22  at a central location. The C-spring extends forwardly and downwardly from the connection with the bracket structure  25  and then curves rearwardly and terminates in a generally horizontal lower tool-receiving end  190  located below the aft portion of the gang tube plate bracket structure  25 . An upper, apertured plate  194  having forwardly converging sides is fixed to the upper surface of the end  190  by two bolts  198 . The apertures for the two bolts  198  are spaced a distance apart equal to the spacing between the bolts  58  on the assemblies  14  and  16  so that the same standards can be used for the single disk and double disk assemblies if desired. 
   Two sets of spacer plates  202  are sandwiched between the bottom surface of the plate  194  and the hub assemblies  50  on opposite sides of the end  190 . The spacer plates  202  assure that the hub assemblies  50  are positioned at the same height above the ground whether connected is a single disk configuration directly to the end  190  ( FIG. 2 ) or in a double disk configuration ( FIG. 4 ) to the plate  194 . 
   As shown, the plate  194  is symmetrical about a fore-and-aft centerline and includes pairs of housing bolt-receiving apertures lying on a line which angles inwardly in the forward direction to define opposite and generally equal disk gang angles which correlate with the disk gang angles defined by the gang tubes  20  and  22  (FIG.  1 ). The spacer plates have inner sides which abut the sides of the end  190  and include apertures corresponding to those in the plate  194 . Bolts  258  extend through the apertures and secure the housings  60  to the standard  55 . As best seen in  FIG. 5 , the forwardmost bolts  258  lie closely adjacent the sides of the end  190  and the innermost ends  66  of the housings are in close proximity to each other. The reduced width of the housings  60 , substantially less than twice the width of the standard, and the plate mounting structure facilitate support of the disks  128  at an ideal spacing and angle relative to each other to work the soil below the center of the machine without need for a special standard or a short additional gang tube. The thrust loads of the two mounted disks are substantially equal and opposite and therefore balance out thereby reducing the thrust loads on the standard. The mounting bolts and the spindle bolts can be of conventional standard grade construction generally identical to each other to reduce component costs and number of different parts required. 
   Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.