Abstract:
A rotary mower deck assembly has a caster assembly mounted within a spindle hub. The spindle hub is rotated within a hub, which is permanently and rigidly mounted to the mower deck. When rotated, the spindle hub rotates cutting blades mounted within the mower deck. The spindle hub is disposed within the spindle hub to bear the weight of the mower deck assembly.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119(e) to, and hereby incorporates by reference, U.S. Provisional Application No. 61/536,108 filed 19 Sep. 2011. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to mowers and, in particular, this invention relates to self-propelled mowers having mower decks which mow vegetation adjacent to structures, such as fences, buildings and the like. 
     2. Background 
     An inherent design flaw in lawnmower decks is that the casters or supporting structures are outboard of the mower blades. This makes it impossible to trim closely with these interferences adjacent vertical features, such as fences, buildings and the like. Consequently, extensive trimming is necessary to achieve a neat, clipped appearance adjacent these vertical features. 
     SUMMARY OF THE INVENTION 
     This invention provides a mower which can mow significantly closer to these vertical features, thereby eliminating or greatly reducing the additional trimming necessary to achieve a neat and desirable appearance. 
     This machine may include a fixed hub mounted to a mowing deck. Within this hub are angular contact bearings in one embodiment. 
     In one embodiment within these bearings is a second hub, which rotates inside the fixed hub. This second hub is secured by sliding through the bearings from the bottom until a shoulder stops against the previously installed bearings; for example, one at the top and one at the bottom of the fixed hub. 
     The rotating hub may have external threads and a key slot to accept locking nuts, key, and pulley. If present, these are tightened to lock the rotating hub in place. 
     At the bottom of the rotating hub may be a T-shaped flange, which rotates inside a circular groove in the fixed hub to keep dirt out. The spindle portion of the rotating hub may have through holes to admit grease from outside to inside for lubrication. The flange depicted has holes machined in a circle for the purpose of mounting a disk-shaped device to which cutting blades are attached. The spindle portion of the hub may be bored through internally, and caged needle bearings may be press fit inside each end. 
     Inside the rotating hub is a stem and caster assembly in the embodiment shown. The stem is fit to rotate independent of the rotating hub within the caged needle bearings. At the top of the caster stem is a drilled and tapped bolt hole, which accepts a thrust bearing and shoulder bolt. The shoulder bolt and thrust bearing secure the caster assembly in position. 
     Above the caster is a beam mounted rigidly to the mower deck. This beam has a hole through which a height adjustment device rests on top of the thrust bearings on the casters. The deck is carried on the casters while allowing the cutting spindle to rotate independently. Cutting height is adjusted by moving the caster up or down vertically and locking it in place. 
     This machine can be mounted singularly or in multiple units synchronized with each other to obtain a wider cutting area. 
     Some nonlimiting features of this design include: 
     
         
         1) Ability to mow more closely with less need for trimming. 
         2) Lack of wheel marks in the grass because the blade passes behind the caster. 
         3) Lack of “scalping” caused by uneven mowing. 
         4) Easy mowing height adjustment. 
         5) Time and money savings. 
         6) Elimination of outboard obstructions, caster brackets, antiscalp casters, etc. 
         7) Option for rigid mount or floating. 
         8) Adjustable rake angle. 
       
    
     Accordingly, a mower deck assembly is provided by this invention, the mower deck assembly having a deck, an exterior hub, a spindle hub, a plurality of first bearings, a pulley, a cutting blade assembly, a caster assembly, at least one second bearing, and a lubrication pathway. The exterior hub may be mounted to the deck such that the hub cannot move independently of the deck. The spindle hub may be rotatively disposable within the exterior hub. The plurality of first bearings may be disposed so as to allow rotation of the spindle hub independent of the exterior hub. The pulley may be rigidly attached to the spindle hub. The cutting blade assembly may be rotated by the spindle hub. The vertically adjustable caster assembly may be rotatively disposable within the spindle hub. The at least one second bearing may be disposable so as to allow the spindle hub to rotate independently of the caster assembly. The lubrication pathway may extend from an exterior surface of the exterior hub, through the spindle hub to the caster assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial sectional view of one embodiment of the mower deck of this invention. 
         FIG. 2  is a partial sectional view of the mower deck of  FIG. 1 . 
         FIG. 3  is bottom view of one embodiment of the cutting blade assembly of this invention. 
     
    
    
     It is understood that the above-described figures are only illustrative of the present invention and are not contemplated to limit the scope thereof. 
     DETAILED DESCRIPTION 
     Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. The materials, methods, and examples described and depicted are illustrative only and not intended to be limiting. 
     Any references to such relative terms as vertical or the like are intended for convenience of description and are not intended to limit the present invention or its components to any one positional or spatial orientation. Dimensions of the components in the attached figures may vary with a potential design and the intended use of an embodiment of the invention without departing from the scope of the invention. 
     Each of the additional features and methods disclosed herein may be utilized separately or in conjunction with other features and methods to provide improved devices of this invention and methods for making and using the same. Representative examples of the teachings of the present invention, which examples utilize many of these additional features and methods in conjunction, will now be described in detail with reference to the drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Therefore, only combinations of features and methods disclosed in the following detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative and preferred embodiments of the invention. 
     A person of ordinary skill in the art will readily appreciate that individual components shown on various embodiments of the present invention are interchangeable to some extent and may be added or interchanged on other embodiments without departing from the spirit and scope of this invention. 
     The foundation of one embodiment of the mower deck assembly  60  of this invention is an exterior hub  5  fixed permanently and rigidly to mower deck  23  top or bottom side such that the hub  5  cannot move or displace independently of the mower deck  23 . Within this hub  5  is a bore  29  with two larger bores  28 ,  29   a , one at each end, each creating a shoulder  30 ,  31 . On these shoulders  30 ,  31  are pressed the outer races  32 ,  33  of angular contact bearings  18 . On the outside of the fixed hub  5  is an externally mounted grease zerk  19  with passage  34  to the angular contact bearings  18  and caged needle bearings  6 . 
     A hollow flanged spindle hub  20  is allowed to slide from the bottom through the two angular contact bearings  18 . The flanged hub  20  has a shoulder  35 , which rests against the bottom bearing  18 . At the top of the flanged spindle hub  20  is a threaded section  36  with a key slot  37  running vertically to which is installed a large washer seal  17 . On top of this washer seal  17  is a threaded nut  16   a  with a key slot  38 , which is screwed down to make contact with the washer seal  17 . The nut  16   a  is screwed down snugly but not so tight as to impede rotation of the spindle hub  20  within the fixed hub  5 . On top of this nut  16   a  is a spider-like lock washer  15  with an internal tang  39   a , which rests within the key slot  37  on the exterior of the spindle hub  20 . A pulley  4  with a second spindle nut  16   b  is threaded on top of the lock washer  15 . One of the external tangs  39   b  of the lock washer  15  is engaged into the receptacle slot  40  in the bottom nut  16   a , fixing it securely to the rotating spindle hub  20 , key slot  38  and receptacle slot  40  being identical. The top nut  16   b  is secured with the pulley  4  sandwiched between the lock washer  15  and itself, i.e., top nut  16   b.    
     Within the spindle hub  20  is a bore  44  with two larger bores  42 ,  43 , one at each end, each creating a shoulder  44 ,  45 . On these shoulders  44 ,  45  are pressed caged needle bearings  6 . The unthreaded portion of spindle hub  20  has through holes  46  to allow grease to migrate from the external fixed hub  5  through the flanged spindle hub  20  to caged needle bearings  6 . The flange  47  itself is recessed on the inner side  48  with a raised section  49  about its circumference. On the face of the flange  47  are drilled and tapped bolt mounting holes  50  to which a cutting blade assembly  61  may be attached. In the embodiment shown, the cutting blade assembly has a disk-shaped device  7  with cutting blades  9 , which are attached with disk mounting bolts  21 . 
     The raised section of flange  49  mates with a circular groove  51  in the bottom of the fixed hub  5 . These mating parts  5 ,  20  have clearance to allow the raised section of flange  49  to rotate within the groove  51  of the fixed hub  5  while acting as a dam to keep dirt and contaminants out. 
     The disk device  7  has two or more detachably mounted cutting blades  9 , which in one embodiment may be turned over to expose a sharp edge on an opposite side or removed to sharpen or replace. The blades  9  are mounted on shouldered blade mounts  10 , which allow the blades  9  to rotate freely about bolt mounting axis to avoid obstruction damage while the disk  7  is revolving, as opposed to a fixed blade. The disk  7  also has a large hole  52  in the center, through which the caster assembly  25  is installed and bolt mounting holes  50  to attach to the rotating hub flange  47 . 
     The caster assembly  25  consists of a wheel  53  and caster  54  on one end and an internal threaded hole  55  on top of the hardened steel shaft  14 , which acts as the inner race for the caged needle bearings  6 . The caster assembly  25  is assembled through the disk  7 , rotating flanged hub  20 , both sets of caged needle bearings  6 , and secured top-side with a shoulder bolt  12  and thrust bearing  13 . The caster assembly  25 , thrust bearing  13 , and shoulder bolt  12  are free to slide axially, e.g., vertically, within caged needle bearings  6  to accommodate adjustment height of cutting blades  9  while allowing flanged hub blades  9  and disk  7  to revolve around caster assembly axis freely for cutting of vegetation. To the top of the mower deck  23  is mounted two posts  3  rising vertically and terminating at a hollow tube or beam  2  connecting the two posts  3  horizontally. The hollow tube  2  with a through hole  56  is mounted permanently to the beam  2  vertically above the center axis of the caster assembly  25 . A hollow height adjusting tube  1  with offset through holes  57 , 90 degrees apart, is allowed through the beam tube  2  to rest one end of top of thrust bearings  13 . A pin  26  or equivalent connector, will slide through the beam tube hole  56  and aligned hole  57  in adjusting tube  1 . Moving adjusting tube  1  up and down and rotating 90 degrees will give a series of height adjustments above the caster stem  14  to regulate various cut heights of rotating blades  9 . A person of ordinary skill in the art will readily recognize other height-adjusting methods, e.g., threaded bolts and nuts or hydraulic rams, would be within the scope of this invention. 
     A compression spring  58   a  may be present about connecting posts  3  to allow horizontal beam  2  or a spring  58   b  above caster spindle thrust bearing  13  to vertically translate and maintain contact, or compensate for uneven surfaces being mowed. 
     Lubrication is obtained by an external-mounted grease zerk  19  on deck-mounted hub  5  in an entry to a lubrication pathway  63 . The grease migrates in the lubrication pathway  63  through the passage to lubricate the two angular contact bearings  18 , which allows the hollow flanged spindle hub  20  to rotate within the mounted hub  5 . From there the grease moves through lubrication passage holes within the hollow flanged spindle hub  20  to the 2 caged needle bearings  6  mounted inside the flanged spindle hub  20 . These bearings allow the flanged spindle hub  20  to spin around the caster stem  14  while allowing the caster stem  14  to rotate and slide up and down vertically for height adjustment. 
     This spindle assembly may be used singly, doubly, or three or more may be ganged up totally from underneath, without the need for external deck supports. 
     Because numerous modifications of this invention may be made without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. Rather, the scope of the invention is to be determined by the appended claims and their equivalents.