Abstract:
A lawn mower includes a cutting deck, a cutting blade positioned underneath the cutting deck, a prime mover driving rotation of the blade, a plurality of wheels supporting the cutting deck, a handle extending upward from the deck, and a clamp mechanism. The clamp mechanism is actuable without the use of tools to clamp the handle against a portion of the deck to fix by friction alone the handle against pivoting with respect to the deck. The mechanism may also be unclamped to permit the handle to pivot with respect to the deck. The clamp mechanism may in some embodiments include first and second clamp mechanism that clamp first and second portions of the handle to respective first and second portions of the deck.

Description:
BACKGROUND 
       [0001]    The present invention relates to a quick release clamp for permitting the quick adjustment of the height of a handlebar on a lawn mower. 
       SUMMARY 
       [0002]    In one embodiment, the invention provides a lawn mower comprising: a cutting deck; a cutting blade positioned underneath the cutting deck; a prime mover driving rotation of the blade; a plurality of wheels supporting the cutting deck; a handle extending upward from the deck; and a clamp mechanism actuable without the use of tools to clamp the handle against a portion of the deck to fix by friction alone the handle against pivoting with respect to the deck, and to unclamp the handle from the deck to permit the handle to pivot with respect to the deck. 
         [0003]    In another embodiment, the invention provides a lawn mower comprising: a cutting deck having first and second mounting portions; a cutting blade positioned underneath the cutting deck; a prime mover to rotate the blade; a plurality of wheels supporting the cutting deck; a handle having first and second legs and being pivotable with respect to the deck to position the handle at a desired height for an operator; and a first and second mechanisms that clamp the respective first and second legs to the respective first and second mounting portions of the deck to fix with friction alone the handle against pivoting with respect to the deck when the mechanisms are in clamped positions, and that permit pivoting of the handle with respect to the deck when the mechanisms are in unclamped positions. 
         [0004]    In another embodiment, the invention provides a method of adjusting the height of a handle of a lawn mower that includes a deck, a cutting blade positioned below the deck, and an internal combustion engine driving rotation of the cutting blade, the method comprising: pivotably coupling a lower end of the handle to the lawn mower deck; pivoting the handle with respect to the deck to position the handle at a desired height; and clamping a portion of the handle to a portion of the deck to fix by friction alone the handle against pivotal movement with respect to the deck. 
         [0005]    Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a perspective view of a lawn mower and clamp mechanism according to one embodiment of the invention. 
           [0007]      FIG. 1A  is an enlarged side view of the lawn mower and clamp mechanism of  FIG. 1 . 
           [0008]      FIG. 2  is a cross-sectional view taken along line  2 - 2  in  FIG. 1A , and illustrating the clamp mechanism in an unlocked condition. 
           [0009]      FIG. 3  is a cross-sectional view taken along line  2 - 2  in  FIG. 1A , and illustrating the clamp mechanism in a locked condition. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
         [0011]      FIG. 1  shows a walk behind lawn mower  10  having a cutting deck  15  and a rotatable blade  17  positioned below the cutting deck  15 . A prime mover, such as an internal combustion engine  20  drives the blade  17 . The lawn mower  10  is movably supported by a plurality of wheels  25 , any or all of which may in some embodiments be driven by the engine  20  or roll passively under the influence of an operator pushing the lawn mower  10 . The lawn mower  10  further includes a handle  30  extending upwards at an angle Θ from rear deck portions or mounting portions  35 . A first rear deck portion  35  is positioned above a first rear wheel  25  and a second rear deck portion  35  is positioned above a second rear wheel  25  on the other side of the lawn mower  10 . The second rear deck portion  35  is obstructed from view in  FIG. 1  by the engine  20 , but is a substantial mirror image of the first rear deck portion  35 . 
         [0012]    The handle  30  includes first and second legs  37 ,  38  that include ends positioned adjacent to the respective first and second rear deck portions  35 . Each leg  37 ,  38  of the handle  30  is rotatably or pivotably coupled to the associated rear deck portion  35  with a pivot bolt  39  that defines a pivot axis for the leg  37  or  38 . The handle is releasably secured against pivoting about the pivot bolt  39  by way of an adjustable clamp mechanism  40  that will be described in greater detail with reference to  FIGS. 2 and 3 . The pivot axes defined by the pivot bolts  39  are preferably collinear to define a single pivot axis P for the overall handle  30 . A dead man handle  42  is provided on the upper portion of the handle  30 . The dead man handle  42  is electrically connected to the engine  20  such that if the handle  42  is released it opens the engine ignition circuit to kill the engine  20 . 
         [0013]    As seen in  FIG. 1A , a portion of each adjustable mechanism  40  is in an arcuate slot  45  in the rear deck portion  35 . As will be described in more detail below, each adjustable mechanism  40  can be actuated to clamp the associated handle leg  37  or  38  to the associated rear deck portion  35 , or can be actuated to release the leg for movement with respect to the associated rear deck portion  35 . When both adjustable mechanisms  40  are released, the handle  30  is free to pivot about the pivot axis P defined by the pivot bolts  39 . While the handle  30  is pivoted about the pivot bolts  39 , the height and angle Θ of the handle  30  are adjusted and the adjustable mechanisms  40  move along their associated arcuate slots  45 . In other embodiments, it is possible that the adjustable mechanisms  40  may act as the pivot points of the legs  37 ,  38 , thereby removing the need for the arcuate slots  45  and pivot bolts  39 . 
         [0014]      FIGS. 2 and 3  show one of the adjustable mechanisms  40 . The following description of the adjustable mechanism  40  applies with equal force to the other adjustable mechanism  40 , which may be a substantial mirror image of the one illustrated. The illustrated mechanism  40  shown is similar in function to Southco Part No. 19-14-10. A generally planar portion  47  of the handle  30  is positioned adjacent and generally parallel to a generally planar portion  48  of the rear deck portion  35 . 
         [0015]    The mechanism  40  includes a lever  50  and a body  55 . The illustrated lever  50  has a cam surface  65  and an abutment portion  70 . The abutment portion  70  serves as a stop to limit movement of the lever  50 . In another embodiment, the lever  50  does not have an abutment portion  70 . The cam surface  65  is in contact with a washer  80 . The washer  80  has a surface  85  adjacent to a generally planar portion  90  of the lawn mower handle  30 . 
         [0016]    The body  55  includes a nut  95  having a surface  100 , and a shaft  105 . The surface  100  is adjacent to a generally planar portion  110  of the deck  15 . The nut  95  is threaded onto the shaft  105  and moves with the shaft  105 . The shaft  105  extends through the slot  45 , handle  30 , and washer  80 , and is pivotably coupled to the lever  50  by a dowel  115 . The shaft  105  is movable with respect to the washer  80 . In the unlocked or unclamped position (shown in  FIG. 2 ), the distance between the nut  95  and washer  80  is maximized and the distance between the dowel  115  and the washer  80  is minimized—thereby relieving clamping pressure. When clamp pressure is relieved, the handlebar  30  can pivot to the desired angle Θ and height. 
         [0017]    In other embodiments of the invention, the relative positions of the handle  30  and rear deck portion  35  can be reversed (or the mechanism  40  reversed) such that the handle  30  is on the nut  95  side and the rear deck portion  35  is on the lever  50  side. Also, in different embodiments the surfaces  85 ,  100  of the washer  80  and nut  95  may be smooth or serrated to facilitate a frictional engagement with the surfaces  90 ,  110 . 
         [0018]    Turning to  FIG. 3 , when the lever  50  is pivoted to the locked or clamped position, the cam surface  65  bears against the washer  80 , and the geometry of the cam surface  65  draws the dowel  115  to move to the left as viewed in  FIG. 3 . As the dowel  115  moves to the left so do the shaft  105  and nut  95 . Friction between the surfaces  85 ,  100  and the respective generally planar portions  90 ,  110 , and friction between the generally planar portions  47 ,  48 , inhibits relative pivotal movement of the handlebar  30  and the rear frame portion  35 . In other words, the handle legs  37 ,  38  are clamped to the rear deck portions  35  when the lever  50  is pivoted to the locked or clamped position. In the locked position, the distance between the nut  95  and washer  80  is minimized and the distance between the dowel  115  and the washer  80  is maximized. Although the nut  95  and washer  80  are used in the illustrated embodiment, the mechanism  40  may include any other suitable first and second members to squeeze the legs  37 ,  38  against the respective deck portions  35 . 
         [0019]    In the illustrated embodiment, the handle  30  is not locked by a ratchet, finger, or detent system that only allow locking at specific intervals or angular positions. Rather, the handle  30  and adjustable mechanism  40  can be infinitely adjusted within a range of angles Θ and heights, because the handle  30  and deck portion  35  are inhibited from pivoting with respect to each other by frictional clamping forces (i.e., between the planar surfaces  47 ,  48 , and between the surfaces  85 ,  100  and the respective planar surfaces  90 ,  110 ) alone. The frictional interface can be enhanced or improved by incorporating a friction-increasing surface on the generally planar portions  47 ,  48 . Such friction-increasing surfaces may include for example, a roughened surface or a rubber or other high-friction material applied to one or both of the generally planar portions  47 ,  48 . 
         [0020]    In operation, to move the handle  30  to a different position, the lever  50  is pivoted to the unlocked position, as shown in  FIG. 2 , which releases the clamping force on the handle  30  and the rear frame member  35 . The handle  30  is then pivoted about the pivot axis P defined by the pivot bolts  39  to any desired position or angle Θ within the range of possible positions or angles as the shaft  105  moves within the slot  45 . To lock the lawn mower handle  30  in the desired position or angle Θ, the adjustable mechanism  40  is moved from the unlocked position to the locked position. In the locked position, the handle  30  and the rear frame member  35  are clamped together on one or both the left and the right sides of the lawn mower  10 . No tools are needed for an operator to adjust the height or angle Θ of the handle  30  because the lever  50  is actuated by hand. 
         [0021]    In the illustrated embodiment, one mechanism  40  is provided on each side of the handle  30  to clamp the ends of the legs  37 ,  38  of the handle  30  against respective rear frame portions  35  on the lawn mower  10 . The first mechanism  40  clamps the surfaces  85 ,  100  against the respective generally planar surfaces  90 ,  110 , and clamps generally planar portions  47  and  48  together, on a first side of the lawn mower  10 . The second mechanism  40  clamps the surfaces  85 ,  100  against the respective generally planar surfaces  90 ,  110  and clamps generally planar portions  47  and  48  together, on a second side of the lawn mower  10 . 
         [0022]    In other embodiments, one mechanism  40  may clamp one of the legs  37 ,  38  of the handle  30  to a rear frame portion  35  on only one side of the lawn mower  10 . In yet another embodiment, it is envisioned that one mechanism  40  will simultaneously clamp first and second side members or the left and right sides of the handle  30  to the left and right rear frame portions  35 . For example, a single shaft  105  may extend between the rear frame portions  35  and slide axially in response to actuation of a single lever  50  to simultaneously tighten the left and right sides of the handle  30  to the respective rear portions  35 . 
         [0023]    Various features and advantages of the invention are set forth in the following claims.