Abstract:
A tiller ( 10 ) having an engine ( 24 ), a plurality of rotating times ( 20 ), and a handle ( 26 ) which are rotatable with respect to a main frame ( 12 ) of the tiller ( 10 ) and cooperate with pivoting wheels ( 14 ) to facilitate turning of the tiller ( 10 ) while maintaining balance and stability.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
         [0001]    This application claims the benefit of U.S. provisional patent application Serial No. 60/192,857, filed Mar. 29, 2000.  
         FIELD OF THE INVENTION  
         [0002]    The present invention relates to a tiller and more particularly to a tiller including an engine, a plurality of rotating tines, and a handle which rotate with respect to a main frame of the tiller.  
         BACKGROUND OF THE INVENTION  
         [0003]    Tillers are typically used to cultivate soil in flower and vegetable gardens, lawns, and the like. The tiller prepares the ground for planting of seeds and seedling plants. Conventional tillers require considerable strength by the user to control and steer the tiller due to the size, weight, and lack of stability of the tiller.  
           [0004]    Some tillers have tines or soil churning members disposed at the rear of the tiller behind a pair of wheels and an engine. Other tillers have tines disposed at the front of the tiller in front of the wheels and the engine. Tillers have been produced, such as disclosed in U.S. Pat. No. 5,896,931, where the handle of the tiller can be pivoted with respect to a main frame of the tiller. The pivoting of the handle converts the tiller from a rear tine type to a front tine type. With the pivoting handle tillers of the prior art, considerable strength is still required by the user to control and steer the tiller due to the size, weight, and lack of stability of the tiller.  
           [0005]    It would be desirable to produce a tiller which maximizes the stability of the tiller, minimizes the strength required by the user to turn and control the tiller, and remains level with the ground during operation.  
         SUMMARY OF THE INVENTION  
         [0006]    Consistent and consonant with the present invention, a tiller which maximizes the stability of the tiller, minimizes the strength required by the user to turn and control the tiller, and remains level with the ground during operation, has surprisingly been discovered. The tiller comprises: a main frame; a plurality of ground engaging wheels, the wheels being spaced apart to support the main frame for movement on the ground; a plurality of tilling tines mounted to rotate about a first axis and to rotate relative to the base about a second axis; a prime mover mounted to deliver power to the tines to effect rotation about the first axis; and a handle adapted for rotating the tines about the second axis. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    The above, as well as other objects, features, and advantages of the present invention will be understood from the detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings, in which:  
         [0008]    [0008]FIG. 1 is a top view of the tiller incorporating the features of the invention;  
         [0009]    [0009]FIG. 2 is a top view of the tiller illustrated in FIG. 1 showing the handle, engine, and tines rotated 180 degrees from the position illustrated in FIG. 1;  
         [0010]    [0010]FIG. 3 is an elevation view of the tiller illustrated in FIGS. 1 and 2;  
         [0011]    [0011]FIG. 4 is a partial elevation view showing the means for raising and lowering the tines of the tiller illustrated in FIGS. 1, 2, and  3  with the track shown in section;  
         [0012]    [0012]FIG. 5 is a partial elevation view showing the drag assembly of the tiller illustrated in FIGS. 1, 2, and  3 ; and  
         [0013]    [0013]FIG. 6 is a partial perspective view showing the upper idler wheel, the lower idler wheel, the guide track and the tension adjuster of the drag assembly illustrated in FIG. 5. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]    Referring now to the drawings, and particularly FIG. 1, there is shown generally at  10  a tiller incorporating the features of the invention. The tiller  10  includes a main frame  12 . Two ground engaging front wheels  14  are disposed on the front portion of the main frame  12 . It is understood that other wheel configurations can be used. One end of a connecting arm  16  is disposed on the main frame  12  and the connecting arm  16  extends forwardly and laterally from the front portion of the main frame  12 . The front wheels  14  are pivotally disposed on the distal end of the connecting arm  16  to permit the front wheels  14  to pivot through 360 degrees. A plurality of mounting holes  18  for the connecting arm  16  are disposed on the main frame  12  for selectively adjusting the wheel track or the distance between the front wheels  14 .  
         [0015]    Rotating tines  20 , an engine base  22 , a prime mover or engine  24 , and a handle  26  are rotatingly mounted in the central portion of the main frame  12 . The handle  26  extends upwardly and laterally from the base  22 . The tines  20  are disposed on a tine shaft  28 , illustrated in FIG. 3. The tine shaft  28  maintains the tines  20  fixed relative to each other. The tine shaft  28  and the tines  20  depend from the base  22 . In alternative embodiments of the invention, the tines  20  are replaced with attachments for conducting lawn and garden maintenance such as, a plug or spike aerator, a power rake, a dethatcher, a snow blower, a trencher, a mowing deck, or a lawn edger, for example. A tine guard  30  is disposed to cover the tines  20 . The tine guard  30  is pivotable with the tines  20 , the base  22 , the engine  24 , and the handle  26  to militate against dirt being thrown into moving parts of the tiller  10  thereby causing undesirable wear.  
         [0016]    In the embodiment shown, a linkage mechanism  32  for raising and lowering the tine shaft  28  and the tines  20  is disposed on the base  22 , as illustrated in FIG. 4. One end of a first linkage arm  34  pivotally depends from the base  22 . The other end of the first linkage arm  34  is connected at a pivot point  36  to one end of a second linkage arm  38 . The other end of the second linkage arm  38  is pivotally connected to one end of a cover  39  which rotatingly supports the tine shaft  28 . One end of a third linkage arm  40  is connected at the pivot point  36  to the first linkage arm  34  and the second linkage arm  38 . The other end of the third linkage arm  40  has a roller  42  disposed thereon. A fourth linkage arm  44  has one end pivotally connected to the roller  42  and the other end pivotally connected to a lever  46 . The lever  46  has one end pivotally disposed on a lever mounting bracket  48  which is fixedly disposed on the base  22 .  
         [0017]    A plurality of locking holes or notches  50  are formed in the mounting bracket  48 . A spring loaded locking mechanism  52  is provided on the lever  46  to engage the locking holes  50  to selectively position the lever  46  at a variety of settings. The locking mechanism  52  is actuated by a knob or handle  54  connected to the locking mechanism  52  by a rigid cable or rod  56 . The roller  42  is disposed in a track  58  to permit the second linkage arm  38  to axially move within the track  58 . The track  58  is fixedly disposed on the base  22  and extends upwardly and angularly from the base  22 .  
         [0018]    The linkage mechanism  32  is shown in FIG. 4 with the tine shaft  28  in a partially raised position. When the tine shaft  28  is in the fully lowered position, a stop  60  prevents the linkage mechanism  32  from being further operated.  
         [0019]    The cover  39  is pivotally connected to a drive shaft  62  at the end opposite from the tine shaft  28 . The cover  39  conceals a drive chain (not shown) and a plurality of sprockets (not shown) which drivingly connect the tine shaft  28  and the drive shaft  62 . The tine shaft  28  and drive shaft  62  are drivingly coupled to the engine  24  through a speed reduction device (not shown). Any conventional coupling means may be used such as, for example, a drive chain, a drive belt, and the like. The tines  20  can be driven forward or in reverse. The drive shaft  62  is rotatingly supported by a bracket  64  which depends from the base  22 .  
         [0020]    A counter weight  66  is disposed at the end of the cover  39  adjacent the drive shaft  62  to minimize the force required to raise the tine shaft  28 . A spring (not shown) can be disposed between the base  22  and one or more of the first linkage arm  34 , the second linkage arm  38 , and the cover  39 . The spring urges the one or more of the first linkage arm  34 , the second linkage arm  38 , and the cover  39  to minimize the force required to raise the tine shaft  28 .  
         [0021]    It is understood that other linkage mechanisms could be used such as, for example, cables or rods directly connected to the tine shaft  28  and other combinations of linkage arms.  
         [0022]    A ground engaging rear wheel  68  is centrally disposed on the rear portion of the main frame  12 , as illustrated in FIG. 1. In the embodiment shown, the rear wheel  68  rotates in a fixed direction. Alternatively, the rear wheel  68  is pivotally mounted and the front wheels  14  are rotated in a fixed direction. In another embodiment, dual rear wheels are provided. In yet another embodiment, the rear wheel  68  is driven by the engine  24  through a variable speed reducer permitting the rear wheel  6 B to be driven both forward and in reverse.  
         [0023]    A locking device  70  is provided to hold the base  22  in the desired position. The locking device  70  employs a spring-loaded pin  72  which cooperates with one of a plurality of protuberances  74  on the main frame  12  arranged circumferentially and radially outwardly of the base  22 . The pin  72  is manipulated using a rigid rod  76  connected to a trigger  78 . The spring urges the pin  72  into engagement with one of the protuberances  74  to militate against turning of the base  22  relative to the main frame  12 . It is understood that other devices could be used to manipulate the pin  72  such as a cable in conduit linkage device, for example.  
         [0024]    A drag assembly  80  is disposed on the rear portion of the main frame  12 , as illustrated in FIGS. 3, 5, and  6 . The drag assembly  80  ensures efficient operation of the tiller  10  by restricting the forward movement of the tiller  10  and causing the tines  20  to work to the desired depth. The drag assembly  80  also breaks up the soil compacted by the rear wheel  68 .  
         [0025]    One end of a drag linkage  82  is pivotally disposed on an axle  84  of the rear wheel  68 . A drag blade or depth stake  86  is disposed on the other end of the drag linkage  82 . The drag blade  86  extends downwardly from the drag linkage  82  for engaging the ground. A foot pad  88  is disposed at the upper end of the drag blade  86  to be engaged by the operator&#39;s foot to cause the drag blade  86  to engage the ground in hard soil conditions, for example.  
         [0026]    One end of a guide track  90  is pivotally disposed on the drag linkage  82  adjacent the drag blade  86 . The guide track  90  is arcuate in shape and extends upwardly and forwardly from the drag linkage  82 , generally following the peripheral surface of the rear wheel  68 . The distal end of the guide track  90  is disposed between an upper idler wheel  92  and a lower idler wheel  94  The lower idler wheel is disposed in a slot  96  formed in the main frame  12 . One end of an upper idler wheel bracket  98  rotatingly supports the upper idler wheel  92 . The other end of the upper idler wheel bracket  98  is pivotally disposed in the main frame  12 .  
         [0027]    A threaded tension adjuster  100  is disposed in a threaded collar  102 . The threaded collar  102  is disposed on the main frame  12 . One end of the tension adjuster  100  abuts the upper idler wheel bracket  98 . The tension adjuster  100  is rotated to selectively cause the tension adjuster  100  to urge the upper idler wheel bracket  98  and the upper idler wheel  92  downwardly against the guide track  90  or lessen the force exerted on the upper idler wheel bracket  98 .  
         [0028]    A locking mechanism  104  is disposed on a central portion of the drag linkage  82 . The locking mechanism  104  includes a spring  105 . The spring  105  urges the locking mechanism  104  to engage a locking stud  106  disposed on the main frame  12  when the drag assembly  80  is in the raised position. The locking mechanism  104  and the locking stud  106  cooperate to lock the drag assembly  80  in a disengaged position out of the soil when the tiller  10  is being transported or operated in reverse.  
         [0029]    It is understood that a conventional drag assembly  80  could be used such as a manual assembly which is manually locked in the desired position, for example. Alternatively, a spring (not shown) could be used to urge the drag assembly  80  downwardly.  
         [0030]    The tiller  10  controls are disposed on the handle  26 . The controls include a drive lever  108  for engaging and disengaging the drive unit for the tines  20 , throttle for the engine  24 , and safety devices, for example.  
         [0031]    A plurality of weight mounting devices (not shown) is disposed on the front and rear portions of the main frame  12  and the base  22 . The weight mounting devices permit weight to be added to the tiller  10 . The additional weight keeps the weight distribution constant relative to the tines  20  during use. The additional weight also ensures that the maximum digging depth of the tines  20  is reached.  
         [0032]    In operation, the tines  20  cultivate the soil and propel the tiller  10  in the desired direction. When turning the tiller  10 , at the end of a row for example, the pin  72  is removed from engagement with one of the protuberances  74 . The pin  72  is retracted by depressing the trigger  78  causing the pin  72  to disengage with the one of the protuberances  74  currently engaged. When the pin  72  is in the disengaged position, the base  22  is permitted to freely rotate relative to the main frame  12 . A lateral force is applied to the handle  26  to thereby cause the tines  20 , the base  22 , and the engine  24  to rotate with respect to the main frame  12 . The front wheels  14  are caused to turn and the tines  20  propel the tiller  10  in the desired direction, thereby causing the tiller  10  to turn. Once the turn is complete, a lateral force is applied to the handle  26  to cause the tines  20 , the base  22 , and the engine  24  to rotate to the desired position to effect the desired motion. The trigger  78  is then released to re-engage the pin  72  with one of the protuberances  74 .  
         [0033]    Raising and lowering of the tine shaft  28  and the tines  20  are accomplished by manipulating the linkage mechanism  32 . To raise the tine shaft  28  and the tines  20 , the handle  54  is manipulated to disengage the locking mechanism  52  from one of the locking holes so and the handle  54  is moved forwardly which causes the fourth linkage arm  44  to axially move the third linkage arm  40  forwardly. The third linkage arm  40  thereby causes the first linkage arm  34  and the second linkage arm  38  to be pivoted with respect to the base  22  and the cover  39 , respectively. The cover  39  thereby is caused to pivot upwardly with respect to the base  22 , causing the tine shaft  28  and the tines  20  to be raised. To lower the tine shaft  28  and the tines  20 , the handle  54  is moved rearwardly which causes the fourth linkage arm  44  to axially move the third linkage arm  40  rearwardly. The third linkage arm  40  thereby causes the first linkage arm  34  and the second linkage arm  38  to be pivoted with respect to the base  22  and the cover  39 , respectively. The cover  39  is caused to pivot downwardly with respect to the base  22  thereby causing the tine shaft  28  and the tines  20  to be lowered. The tine shaft  28  and the tines  20  can be locked at a desired position by engaging the locking mechanism  52  with one of the locking holes  50 .  
         [0034]    The drag assembly  80  is operated by engagement of the rear wheel  68  and the lower idler wheel  94 . The lower idler wheel  94  is caused to rotate by the rear wheel  68 . When the tiller  10  is operating in the forward direction, the lower idler wheel  94  causes the guide track  90  to be driven downwardly to cause engagement of the drag blade  86  with the soil. The amount of engagement force between the lower idler wheel  94  and the rear wheel  68  is adjusted by selectively rotating the tension adjuster  100  which increases or decreases the force being applied to the upper idler wheel  92 . As the upper idler wheel  92  is urged downwardly against the guide track  90 , the guide track  90  is urged against the lower idler wheel  94 . The lower idler wheel  94  is caused to slide downwardly in the slot  96  and the engagement force between the lower idler wheel  94  and the rear wheel  68  is increased. The increased engagement force causes the downward force on the guide track  90  and the drag blade  86  to increase. Conversely, as the upper idler wheel  92  is cause to move upwardly, the force on the guide track  90  is decreased. The lower idler wheel  94  is permitted to slide upwardly in the slot  96  and the engagement force between the lower idler wheel  94  and the rear wheel  68  is decreased. The decreased engagement force causes the downward force on the guide track  90  and the drag blade  86  to decrease.  
         [0035]    When the tiller  10  is operated in the reverse direction, the reverse rotation of the rear wheel  68  causes the lower idler wheel  94  to drive the guide track  90  upwardly. Therefore, the drag blade  86  is caused to disengage with the soil. If the tiller  10  is driven a sufficient distance in reverse, the locking mechanism  104  will engage the locking stud  106  and lock the drag linkage  82  in the disengaged position. The tiller  10  can then be stored, or the locking mechanism  104  released and the tiller  10  returned to operation.  
         [0036]    From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.