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 .
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 .