Abstract:
A mower comprising a mower housing with an open bottom for mowing underneath the housing. A mower blade is positioned with the housing and is driven by a motor mounted to the housing. A linkage assembly attaches a prime mover to the housing and supports the mower relative to the prime mover wherein the linkage assembly provides vertical and rotational movement of the housing about an axis along a path of travel of the mower.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to linkage assembly for mounting an attachment to a prime mover. In particular, the linkage assembly enables a pitch of the attachment to be initially set and maintained during operation while allowing for vertical movement and rotational movement of the attachment about an axis along a forward path of travel while restricting lateral movement of the attachment.  
         [0002]     Attachments, such as mowers, that are mounted to prime movers, such as skid steer loaders, are known in the art. However, the linkage that attaches the attachment to the prime mover typically does not allow the pitch of the attachment to be set prior to use and maintained during use even as the attachment travels over uneven terrain. Additionally, linkages that mount attachments to prime movers in the prior art do not allow the attachment to float over the terrain by providing for vertical and rotational movement of the attachment. Especially in the case of a mower, the inability of the mower to float about the terrain causes an uneven cutting which may provide a unsatisfactory result.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention includes a mower having a housing with an open bottom for mowing underneath the housing. A mower blade or blades are positioned within the housing and is driven by a motor mounted to the housing. A linkage assembly connects a prime mover to the mower housing where the prime mover moves the housing. The linkage assembly allows the housing to vertically move and rotationally move about an axis along a path of travel while limiting the lateral movement of the mower housing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]      FIG. 1  is a perspective view of a linkage assembly mounting a mower to a prime mover;  
         [0005]      FIG. 2  is a right side view of the linkage assembly of the present invention;  
         [0006]      FIG. 3  is a left side view of the linkage assembly of the present invention;  
         [0007]      FIG. 4  is a sectional view of a ball joint of the present invention along section line  4 - 4  in  FIG. 2 ;  
         [0008]      FIG. 5  is a side view of a shut off valve of the present invention; and  
         [0009]      FIG. 6  is a front view of the linkage assembly of the present invention allowing an attachment to tilt. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0010]     A linkage assembly of the present invention is generally illustrated at  10  in  FIG. 1 . The linkage assembly  10  attaches a flail mower  12  to a prime mover  16 , such as a loader.  
         [0011]     The linkage assembly  10  allows the flail mower  12  to move vertically and rotate about an axis  14  of movement along a forward path of travel while limiting the lateral movement of the flail mower  12  with respect to the loader  16 . The linkage assembly  10  can also be used to mount other attachments besides a flail mower to the loader  16 .  
         [0012]     Referring to  FIGS. 1-3 , the linkage assembly  10  preferably includes three linkages generally parallelly aligned along the axis  14  of the forward path of travel. A left linkage  18  is attached to a left side panel  21  of flail mower housing  24  and proximate a lower left corner  33  of an attachment plate  32  that is mounted to the loader  16 . A right linkage  20  is attached to a right side panel  23  of the flail mower housing  24  and also proximate a lower right corner  31  of the attachment plate  32 . A top linkage  22  is attached proximate a top end  30  of the flail mower housing  24  with a mower mounting bracket  62  and also proximate a top end  38  of the attachment plate  32  with an attachment plate mounting bracket  66 .  
         [0013]     Each of the linkages  18 , 20 , 22  is preferably a rigid member and are approximately the same length. Each of the linkages  18 , 20 , 22  also have ball joints  40  proximate each end for attaching each linkage  18 , 20 , 22  to the flail mower  12  and to the prime mover  16 . Although a linkage assembly  10  having three linkages is preferred, a linkage assembly having four or more linkages is also within the scope of the present invention.  
         [0014]     Each ball joint  40  in the left linkage  18 , the right linkage  20 , and the top linkage  22  are similarly constructed and the components of the ball joint  40  are given the same reference characters. Referring to  FIG. 4 , each ball joint  40  includes a ball  42  that is rotatably captivated with a through bore  44  in the linkage  18 , 20 , 22  defined by an convex arcuate surface  46 . The ball  42  has a width similar to a width of the linkage  18 , 20 , 22 . The ball  42  is retained to either the attachment  12  or the prime mover  16  with a bolt  50  inserted through a through bore  52  in the ball  42  and also through aligned apertures  54  in a mounting bracket  56 . The bolt  50  is threadably retained to the mounting bracket  56  with a threaded engagement with a nut  58 . The mounting bracket  56  may also include only one plate to which the ball joint is attached.  
         [0015]     Although a generally uniform radius ball  42  is preferred, a spheroidal member is also within the scope of the present invention. What is meant by spheroidal is objects having portions of the outer surface which are arcuate although the portion of the outer surface need not be defined by a consistent radial distance from a center of the member such as ellipsoids.  
         [0016]     Referring to  FIGS. 1-3 , the top linkage  22  is mounted to the top mower mounting bracket  62  that is fixedly secured to the flail mower housing  24  proximate the end  30 . The top mounting bracket  62  includes parallel vertical plates  64  that have aligned apertures  54  which are aligned with the through bore  52  in the ball  42 . The bolt  50  is positioned through the aligned through bore  52  and the apertures  54  and secured therein with the nut  58  thereby mounting one end of the top linkage  22  to the flail mower housing  24 .  
         [0017]     The other end of the top linkage  22  is mounted to the attachment plate mounting bracket  66  fixedly attached proximate the top end  38  of the attachment plate  32 . The top linkage  22  is positioned between two parallel vertical plates  68  having aligned apertures  54  and retained to the attachment plate mounting bracket  66  with the bolt  50  positioned through the aligned apertures  54  in the plates  68  and the through bore  52  in the ball  42 .  
         [0018]     The left and right linkages  18 , 20  are adjustably attached to the left and right side panels  21 , 23 , respectively, by positioning the bolt  50  of the ball joint  40  into one of the plurality of apertures  74 , 76  in left and right side panels  21 , 23 , respectively. The apertures  74 , 76  are in a generally arcuate alignment within the side panels  21 , 23  such that adjusting the position of the left and right linkages  18 , 20  on the left and right side panels  21 , 23  of the mower housing  24  adjusts a pitch of the flail mower  12  relative to the attachment plate  32 . By pitch is meant the height of a front end  25  of the housing  24  relative to a back end  27  of the housing  24  at which the attachment is operated. The plurality of arcuate apertures  74 , 76  allows the pitch of the housing  24  to be adjusted from generally parallel to ground level to a raised pitch that raises the front end  25  of the housing  24  such that the flail mower  12  better accepts and cuts brush and other tall vegetation.  
         [0019]     With the mower housing  24  at the selected pitch, the mower housing  24  is moveable in three axes of movement. However, the lateral movement of the mower housing  24  relative to the prime mover  16  is limited by the left and right linkages  18 , 20  contacting the mower housing  24 .  
         [0020]     The left linkage  18  and the right linkage  30  are mounted to both the attachment plate  32  and the flail mower housing  24  to limit lateral movement of the flail mower  12  relative to the loader  16  and also to maintain a parallel alignment of the left and right linkages  18 , 20 , respectively. The left and right linkages  18 , 20 , while each allowing lateral movement of the flail mower housing  24  away from the attachment plate  32 , together limit the lateral movement of the flail mower housing  24  relative to the loader  16 . When the mower housing  24  begins to move laterally left, the left linkage  18  contacts the mower housing  24  thereby limiting lateral movement in a left direction. Similarly, as the flail mower housing  24  begins to move in a right direction, the right linkage  20  contacts the mower housing  24  thereby limiting movement in a right lateral direction. Therefore, the cooperation of the left and right linkages  18 , 20  prevents lateral movement of the mower  12  relative to the attachment plate  32  and the prime mover  16 .  
         [0021]     A height of the flail mower  12  is adjusted with the prime mover  16  by raising or lowering the attachment plate  32  which also raises and lowers the flail mower housing  24 . The housing  24  is lowered until a roller  80  attached proximate a bottom edge  19  of the mower housing  24  contacts a ground surface. Although a roller is illustrated, other ground contacting mechanisms are also within the scope of the present invention including, but not limited to, a skid plate.  
         [0022]     Referring to  FIG. 6 , with the roller  80  engaging the ground, the mower  12  is moved along a path of travel, the left linkage  18 , right linkage  20  and top linkage  22  allow the mower  12  to float on the ground surface whether even or uneven. As the ground surface becomes uneven, the ball joints  40  in the linkages  18 , 20 , 22  allow the mower housing  24  to rotate about the axis  14  of travel and follow the contour of the ground as indicated by the angle θ. Rotation about the axis  14  along the path of travel allows one side of the mower housing  24  to raise or conversely lower while the other side remains at the same vertical position or lowers to follow the contour of the ground.  
         [0023]     Additionally, the mower housing  24  can adjust vertically to follow the contour of the ground. An upper vertical limit is reached when the mower housing  24  engages arms  82  attached to the attachment plate  32  and extending over the housing  24 . Preferably, the arms  82  have pads  84  that contact the mower housing  24  and cushion the impact between the mower housing  24  and the arms  82  when raised by the terrain. When the flail mower  12  is in operation, the floating linkage assembly  10  preferably allows the mower housing  24  to vertically travel about 12 inches.  
         [0024]     Additionally, the linkages  18 , 20 , 22  are also designed to limit the fore and aft movement of the mower housing  24 . Because the linkages  18 , 20 , 22  are of a rigid construction that does not readily expand or contract, the fore and aft movement is limited to between preferably about zero and four inches.  
         [0025]     The mower  12  is raised by raising the attachment plate  32  with the prime mover  16 . As the attachment plate  32  is raised, the left, right and middle linkages  18 , 20 , 22  begin to pivot about the ball joints  40 . The pivoting left and right linkages  18 , 20  contact left and right stops  90 , 92  extending from the mower housing  24 . The contact of the left and right stops  90 , 92  with the left and right linkages  18 , 20 , respectively, prevents further pivotal movement of the left and right linkages  18 , 20  and causes the mower  12  to raise as the attachment plate  32  raises. Preferably, the stops  90 , 92  are constructed of a compressive material such as rubber or a compression spring to limit damage caused by the impact of the left and right linkages  18 , 20  and the left and right stops  90 , 92 .  
         [0026]     Referring to  FIGS. 2 and 5 , as the attachment plate  32  is vertically raised, a cam member  94  that is pivotally attached to a shut off valve  96  contacts the attachment plate  32  and begins to exert a force upon the shut off valve  96 . When the attachment plate  32  is raised to a relative height to the mower housing  24 , the cam member  94  exerts a sufficient force upon the shut off valve  96  to shut off hydraulic power to a motor  98  driving flail blades  100 . The shut off valve  96  prevents the flail mower  12  from running at a predetermined height which could be dangerous to the operator or bystanders. Although a shut off valve  96  for a hydraulic system is preferred other actuator mechanisms and different powered systems such as a pneumatic system or an electric system are within the scope of the present invention.  
         [0027]     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.