Patent Publication Number: US-2007107404-A1

Title: Height adjustment system for a lawn maintenance device

Description:
FIELD OF THE DISCLOSURE  
      The present disclosure generally related to lawn maintenance devices, and more particularly, to a height adjustment system for a lawn maintenance device.  
     BACKGROUND  
      Typically, the left and right hand drive wheels of conventional lawn sweepers are connected by a tube or bar that allows a user to adjust the brush height by a single lever located between the wheels. Disadvantages of this conventional configuration include increased costs, due to the number of parts and difficulty in operation when parts begin to wear and bind. Additionally, other lawn implements have incorporated height adjustment mechanisms at each wheel. However, such implements do not address the particular requirements of lawn sweepers in that the ground engaging wheels of a lawn sweeper must drive the brush that extends between the wheels. Accordingly, conventional lawn sweepers have been configured as described above and independent side-to-side adjustment has been unsuccessful due to issues of binding and misalignment with respect to drive mechanisms. Consequently, the teachings and suggestions of other lawn implements are inapplicable to lawn sweepers.  
      Therefore, there exists a need in the art for a lawn sweeper brush height adjustment that is independent from side-to-side and overcomes disadvantages described above but also uses less material, is easier to assemble and is less costly and provides improved performance in use. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Certain embodiments are shown in the drawings. However, it is understood that the present disclosure is not limited to the arrangements and instrumentality shown in the attached drawings, wherein:  
       FIG. 1  illustrates a side view of a lawn maintenance device having a height adjustment mechanism in accordance with the teachings of the present disclosure;  
       FIG. 2  illustrates an exploded perspective view of the height adjustment mechanism of  FIG. 1 ;  
       FIG. 3  illustrates a perspective fragmentary view of a side portion of the lawn maintenance device of  FIG. 1 ; and  
       FIG. 4  illustrates a perspective bottom view of the lawn maintenance device of  FIG. 1 . 
    
    
     DETAILED DESCRIPTION  
      For the purposes of promoting and understanding the principles disclosed herein, reference will now be made to the preferred embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope is thereby intended. Such alterations and further modifications in the illustrated device and such further applications are the principles disclosed as illustrated therein as being contemplated as would normally occur to one skilled in the art to which this disclosure relates.  
      Referring to  FIG. 1 , a lawn maintenance device  10  constructed in accordance with the teachings of the present disclosure is shown. The lawn maintenance device  10  includes a body  12  having a pair of opposed sidewalls  14 . An axle  16  is housed in the body  12  such that each end  18  of the axle  16  is rotatably mounted to a corresponding sidewall  14 . The lawn maintenance device  10  also includes a pair of height adjustment brackets  20  (as shown in  FIGS. 2 and 3 ). Each height adjustment bracket  20  is rotatably mounted to a corresponding sidewall  14 .  
      Referring to  FIG. 2 , each bracket  20  includes a first end portion  30  that engages a front portion  32  of the sidewall  14 . The front portion  32  of the sidewall  14  includes a first arcuate slot  34 , relative to which the first end portion  30  of the bracket  20  traverses. The bracket  20  also includes a second end portion  40  that is disposed relative to a rear portion  42  of the sidewall  14 . The sidewall  14  includes a second arcuate slot  44  disposed in the rear portion  42 . The second end portion  40  of the bracket  20  traverses relative to the second arcuate slot  44 . The second end portion  40  of the bracket  20  can also engage the sidewall  14  to prevent unintended rotation of the bracket  20  relative to the sidewall  14 . The bracket  20  also includes a pivot portion  50  located between the first end portion  30  and the second end portion  40 . The pivot portion  50  is rotatably connected to a corresponding end  18  of the axle  16 . The lawn maintenance device  10  may also include a pair of wheels  60 , with each wheel being rotatably mounted to the first end portion  30  of the corresponding bracket  20 . Each wheel  60  is operatively coupled to a corresponding end  18  of the axle  16 . Accordingly, rotation of each wheel  60  rotates the axle  16 . The height of the body  12  from the ground can be adjusted by rotation of each of the brackets  20  relative to the corresponding sidewall  14  about the pivot portion  50 .  
      The lawn maintenance device  10  may be any type of device that is commonly used to provide lawn and general landscaping functions. For example, the lawn maintenance device  10  may be a lawn mower such that the axle  16  is connected to plurality of lawn cutting blades (not shown) so that when the lawn maintenance device  10  is pushed or pulled forward the wheels  60  rotate the axle  16  to cut the lawn. In another example, the lawn maintenance device  10  may be a lawn sweeper, such that the axle  16  is connected to a plurality of sweeper blades  62 . Accordingly, when the lawn maintenance device  10  is pushed or pulled forward, the sweeper blades  62  can sweep leaves or other debris off the lawn and push or pull the collected debris into a catch bag  64  that may be mounted to the body  12  at the rear portion of the lawn maintenance device  10 . In the examples disclosed herein, the lawn maintenance device  10  will be described as a lawn sweeper. However, one of ordinary skill in the art will appreciate that the lawn maintenance device  10  may be any type of lawn or landscaping device such as a lawn mower, a fertilizer spreader, an aerator, a thatcher or the like.  
      With typical lawn maintenance devices, regardless of what type of function it provides, a user may push or pull the lawn maintenance device  10  with a handle  66  so that the wheels  60  rotate to thereby rotate the axle  16  to perform the function that is derived by the rotation of the axle  16 . However, in most lawn maintenance devices  10 , it may be necessary to adjust the height of the body  12  relative to the ground to change the degree of functionality that is provided by the lawn maintenance device  10 . For instance, in a lawn mower, the height of the body  12  relative to the ground determines the height of the grass that is cut from the lawn. When the lawn maintenance  10  is a lawn sweeper as illustrated and described herein, the height of the body  12  relative to the ground may determine the number and size of the leaves and other debris that can be collected by the lawn sweeper. Accordingly, the brackets  20  and their associated components that will be described in detail herein, provide height adjustment of the body  12  relative to the ground.  
      Referring to  FIG. 2 , the first end portion  30  of the bracket  20  includes a spindle  70  on which a corresponding wheel  60  is mounted. Accordingly, the wheel  60  rotates on the spindle  70 . The wheel  60  is maintained on the spindle  70  by a bolt  72  that engages a bore  74  of the spindle  70  from the inside of the sidewall  14  through the first arcuate slot  34 . A nut  76  is fastened to the end of the bolt  72  to maintain the wheel  60  on the spindle  70 , while allowing the wheel  60  to spin relative to the spindle  70 . Additionally, the bolt  72  and the nut  76  provide for the first end portion  30  of the bracket  20  to traverse along the first arcuate slot  34 , while preventing the first end portion  30  from disengaging from the first arcuate slot  34 . Therefore, the first end portion  30  of the bracket  20  traverses along the first arcuate slot  34  while being maintained within the path defined by the first arcuate slot  34 . Accordingly, when the first end portion  30  is moved along the arcuate slot  34 , the position of the wheel  60  relative to the body  12  changes such that if the wheel  60  is contacting the ground, the body  12  can be lowered or raised relative to the ground.  
      Referring to  FIGS. 3 and 4 , the wheel  60  includes a wheel housing  80 , in which a wheel gear  82  and an axle gear  84  are housed. The wheel gear  82  is concentric with the wheel  60  and is rotationally mounted on the spindle  70 . Accordingly, the wheel  60  and the wheel gear  82  rotate relative to the spindle  70  while mounted on the spindle  70 . The axle gear  84  is fixedly attached to the end of the axle that protrudes from the sidewall  14  and is housed in the wheel housing  80 . The wheel gear  82  is coupled to the axle gear  84  in such a manner that rotation of the wheel gear  82  will rotate the axle gear  84  only in one desired direction. Therefore when the lawn maintenance device  10  is pushed or pulled such that the wheel  60  turns, the wheel gear  82  rotates thereby causing the rotation of the axle gear  84 , which will rotate to axle  16  to provide the function that is provided by the lawn maintenance device  10 , i.e., rotating the lawn sweeper blades  85 .  
      As discussed in the foregoing, the wheel  60 , including the wheel housing  80  is movable along the first arcuate slot  34  so as to raise and lower the body  12  relative to the ground. Accordingly, the wheel  60  including the wheel housing  80  can traverse along the first arcuate slot  34  without affecting the aforementioned coupling between the wheel gear  82  and the axle gear  84 . The axle  16  protrudes from the sidewall  14  through the pivot portion  50  of the bracket  20  and through the wheel housing  80  as described above. Axle gear  84  is then fixedly attached to the end of the axle  16 , which terminates inside the wheel housing  80 . Therefore the bracket  20  is pivotally mounted on the sidewall  14  by the pivot portion  50  being rotationally mounted on the axle  16 .  
      The second end portion  40  of the bracket  20  enables an operator of the lawn maintenance device  10  to adjust the height of the body  12  relative to the ground. Accordingly, the second end portion  40  simply functions as a handle so that an operator can move the first end portion  30  of the bracket  20  along the first arcuate slot  30  to adjusted height of the body  12  relative to the ground. To maintain the height of the body  12  relative to the ground once the height is adjusted to a desired level, the second end portion  40  includes a protrusion  90  facing the sidewall  14 . A plurality of apertures  92  are disposed at the rear portion  42  of the sidewall  14  in an arc to correspond with the arc that the protrusion  90  of the second end portion  40  traces along the sidewall  14  when the bracket  20  is pivoted about the axle  16 . The apertures  92  may be disposed in equal distances from each other such as to provide discreet and equal height variations for the body relative to the ground. The apertures  92  are sized so as to receive the protrusion  90  when the protrusion  90  is aligned with any one of the apertures  92 . To remove the protrusion  90  from an aperture  92  to adjust the height of the body relative to the ground, the second end portion  40  of the bracket  20  can be pulled outward relative to the sidewall  14  by the operator, so that the protrusion  90  disengages from the aperture  92 . The operator can then pivot the bracket  20  about the pivot portion  50 , i.e. about the axle  16 , to align the protrusion  90  with another one of the apertures  92 . Once the protrusion  90  is aligned with another aperture  92 , the operator can release the second end portion  40  thereby causing the protrusion  90  to engage the aperture  92 . However, to maintain the protrusion  90  engaged with an aperture  92  after the height of the body  12  is adjusted relative to the ground, the bracket  20  includes a locking knob  100  that engages a screw  102  through an aperture  104  in the second end portion  40 . The screw is mounted from the inside of the sidewall  14  through the second arcuate slot  44  and through the aperture  104  thereby allowing the locking knob to be tightened to the end thereof. Therefore by tightening the locking knob  100 , the second end portion  40  can be securely maintained at a desired position along the second arcuate slot  44  once the height of the body  12  is adjusted relative to the ground. Additionally, the locking knob  100  and the screw  102  ensure that the second end portion  40  of the bracket  20  traverses within the second arcuate slot  44  while preventing the second end portion  40  to disengage from the second arcuate slot  44 .  
      As described in the foregoing, an operator can move the second end portion  40  of the bracket  20  along the second arcuate slot  44  and cause the pivoting of the bracket  20  about the axle  16 , thereby moving the first end portion  30  along the first arcuate slot  34  to adjust the height of the body  12  relative to the ground. Therefore, the height of the body  12  relative to the ground can be adjusted through a height that is defined by the range of motion of the first end portion  30  and the second end portion  40  through the first arcuate slot  34  and the second arcuate slot  44 , respectively. The bracket  20  and the above-described associated mechanisms, provide for adjustment of the height of the body  12  relative to the ground without disturbing the drive mechanism by which the wheel  60  can drive the axle  16  to operate the lawn maintenance device  10 . Furthermore, the bracket  20  and its associated mechanisms maintain the adjusted height of the body  12  relative to the ground by engagement of the protrusion  90  with the plurality of apertures  92  and engagement of the locking knob  100  and the screw  102  with the second arcuate slot  44 . Additionally, the engagement of the protrusion  90  with the apertures  92  allow an operator to simply adjust the height of the body  12  relative to the ground by rotating the second end portion  40  of the bracket  20  along the second arcuate slot  44  through the discreet height variations provided by the apertures  92 .  
      Furthermore, while the particular preferred embodiments have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the teaching of the disclosure. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as limitation. The actual scope of the disclosure is intended to be defined in the following claims when viewed in their proper perspective based on the related art.