Abstract:
A mower deck assembly which essentially “flips up” or raises from a mowing configuration to an access configuration-with minimal manipulation of controls and manual lifting. A deck is connected to a frame by a parallelogram suspension which includes front and rear support arms. A rear of the deck removably connects through a height adjustment mechanism that includes the hook and capture device selectively allows the rear of the deck to swing freely so that when the mower is in a non mowing configuration. The deck has mounted thereon a plurality of pulleys, including blade pulleys connected by a single drive belt and driven by a single motor. One of said the pulleys is a tension pulley that can be manipulated to disengage the pulley system. The front of the suspension includes a fine height adjustment mechanism.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to a riding lawn mower and more particularly to a midmount riding lawn mower having a mower deck that is swingable from a mowing configuration to an access configuration having a height adjustment mechanism that easily captures the mower deck for mowing and releases the deck for access and a pair of arms which form a parallelogram when the deck is in the mowing configuration and extend outwardly in the access configuration.  
         [0002]     Prior mowers have included a mower deck that is mounted such that the deck can tilt or rotate to a position conducive for maintenance of the deck&#39;s under housing (e.g. cleaning, replacing blades, etc). Typically, decks of this type have been described as “tiltable” or “tilting” such as in the Sameshima U.S. Pat. No. 5,079,907 and Shroeder U.S. Pat. No. 4,779,406 respectively. Prior art structures have been complicated, hard to operate, expensive to manufacture and/or present other problems both in use in mowing and in trying to convert between a mowing configuration and an access configuration.  
         [0003]     The present invention is especially useful in conjunction with a midmount mower wherein the mower deck is mounted between the front and rear wheels of the device. In such a device, it is desirable to make conversion between the mowing configuration and the access configuration easy and quick. Nevertheless, it is also necessary to provide a support structure for the deck that maintains the deck level during mowing and allows for easy cutting height adjustment. It is also desirable to provide such a device that utilizes a single drive belt that can be easily removed to allow for conversion. Also, a simple to use level adjustment mechanism is desirable to allow for fine adjustment of deck level that is required to correct for damage, tolerance variation or to modify the deck to be slightly non parallel to the ground in accordance with the desires of the operator.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention is directed to a midmount riding mower having improved mechanism for allowing a mowing deck thereof to be easily moved between a mowing configuration and an access configuration wherein an underside of the mower deck is exposed for repair or maintenance.  
         [0005]     The mower includes a support structure for maintaining the mower deck so the blades cut in planes that are generally horizontal relative to the ground. The support structure includes a pair of laterally spaced front legs and a pair of laterally spaced rear legs. The front and rear legs are pivotally connected to a frame of the mower at the same location. The rear legs are medially hinged having an upper portion that abuts the frame along the length thereof during mowing such that the front and rear legs along with a portion of the mower deck between pivotal attachments of the front and rear legs with the mower deck generally form an adjustable support parallelogram to maintain the cutting blades so as to cut generally horizontal to the ground surface.  
         [0006]     Associated with and part of the support structure is the height adjustment mechanism. The height adjustment mechanism includes a pivot bar with a radially extending operating handle and a pair of spaced radially extending arms jointed by an engagement bar at the distal ends thereof. The deck includes hook members that are sized and positioned to engage the engagement bar when the deck is positioned in a non raised position as the pivot bar is rotated by the handle so as to first be captured and then raised. As the deck raises, the parallelogram formed by the support arms keeps the deck level. A pin is used with a blocking arm to keep the deck from inadvertently becoming disengaged from the engagement bar.  
         [0007]     When in the non raised and non engaged position, the deck can be pulled forward on the support arms and thus the front can be raised to an access configuration by extending the rear support arms to an almost linear configuration. The process is reversed to return to a non raised configuration, rejoined with the height adjustment mechanism after which the deck is in the mowing configuration.  
         [0008]     Unlike mowers that normally have a main drive belt and a secondary drive belt that actually turns cutting blades, the drive belt of the mower of this application is a unitary single belt that is reeved to engage the motor as well as pulleys driving each of the cutting blades. A tension release mechanism is provided to release tension from the belt to allow the belt to be removed from a motor pulley and thereby allow the mower deck to be raised to the access configuration thereof.  
         [0009]     A fine tuning level adjustment is also provided with each of the support front legs which allows fine adjustment of the alignment of the mower deck to adjust level that may be required because of variations due to construction variations, damage, or because an operator wants to have the front slightly higher than the rear to better attack grass being cut. The level adjustment includes a clevis that is pivotally joined to each the front leg and which is adjustable from front to rear relative to the mowing deck.  
       OBJECTS AND ADVANTAGES OF THE INVENTION  
       [0010]     Therefore, the objects of the present invention are: to provide a midmount mower having a support structure that maintains the deck generally horizontal to the ground during mowing, but allows the deck to be swung easily to an access configuration for repair or maintenance; to provide such a mower deck having a parallelogram leg configuration to allow the deck to maintain a generally horizontal position at any cutting height during mowing and wherein a rear leg can be extended to allow the deck to easily swing from the mowing configuration to the access configuration; to provide such a mower deck wherein converting from the mowing configuration to the access configuration requires minimal manipulation of controls or apparatus; to provide such a mower with a support structure that extends to an over center configuration, so that when the deck is raised to the access configuration, the configuration is stable; to provide such a mower having a height adjustment mechanism that operates in conjunction with the support structure to allow the mower deck to be easily converted from the access configuration to the mowing configuration, allows for height of cutting adjustment and helps support the rear of the mower deck all under the control of a single adjustment lever by the operator; to provide a plurality of cutter blade pulleys and guide pulleys that are connected by a single belt to a motor pulley, so that a single tension pulley can release tension from the entire system to allow disengagement of the belt; to provide a fine height-adjustment mechanism to allow the front of the deck to be adjusted in both height and angle to accommodate the particular deck and desires of the user; to provide such a mower having a height adjustment mechanism with a rod that can be captured by deck hook by simple movement of the height adjustment lever; to provide such a mower having a mower deck that can be positioned forward of the remainder of the mower for ease of access and simplicity; to provide such a mower that is easy to use, relatively inexpensive to make because of simpler mechanisms and especially well adapted for the intended usage thereof.  
         [0011]     Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.  
         [0012]     The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of a lower heavy mowing deck and a suspension apparatus for the deck in accordance with the present invention.  
         [0014]      FIG. 2  is a side elevational view of the mower illustrating the mowing deck in a mowing and raised configuration.  
         [0015]      FIG. 3  is an enlarged and fragmentary side elevational view of the mower with mower deck in a mowing configuration.  
         [0016]      FIG. 4  is a side elevational view of the mower with the mower deck in a mowing and lowered configuration and just prior to rear disengagement of the mower deck from remainder of the mower to allow flip up of the mower deck.  
         [0017]      FIG. 5  is an enlarged and fragmentary side elevational view illustrating the mower deck in a lowered configuration and showing the supporting mechanism for the mowing deck in a captured configuration in solid lines and in a release configuration in dash lines.  
         [0018]      FIG. 6  is a side elevational view of the mower showing the mowing deck at a mid position between conversion from the mowing configuration to an access configuration.  
         [0019]      FIG. 7  is a side elevational view of the mower showing the mower deck in the access configuration thereof.  
         [0020]      FIG. 8  is a greatly enlarged and fragmentary perspective view of a top of the mower deck and the support mechanism and adjustment devices for use in conjunction with the mower deck.  
         [0021]      FIG. 9  is a fragmentary and enlarged perspective view of a portion of the mower deck and remaining mower with a frontward support and adjustment mechanism thereof. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.  
         [0023]     The reference numeral  1  generally represents a mower incorporating improvements in accordance with the present invention. The mower  1  includes a mobile frame  5 , a mower deck  6  and a support and adjustment structure or mechanism  7  for joining the mower deck  6  to the frame  5 .  
         [0024]     The frame  5  includes a pair of generally parallel, laterally spaced and longitudinally extending tubes or channels  12  and  13  that are sized shaped and positioned to be generally parallel to the ground when the mower  1  is operating as a mower and cutting grass and the like. The channels  12  and  13  are spaced by transverse members, such as front transverse member  15  and by plating such as floor plating  16  and forward cowling  17 , so as to form an overall solid structure to support the mower deck  6 , as described below.  
         [0025]     The mobile frame  5  also includes a pair of front castor wheels  18  and a pair of rear drive wheels  21 . The mower  1  of the present invention is a mid mount or underbelly type mower wherein all or substantially almost all of both the mower deck  6  and support and adjustment mechanism  7  is located from front to rear between the front wheels  18  and the rear wheels  21  wherein the mower  1  is being utilized to cut grass, as is seen in the illustrations shown in  FIGS. 1 and 2 .  
         [0026]     Mounted on the rear of the frame  5  is a motor assembly  25  which operably provides power to the drive and operate the mower  1  through well known hydraulic wheel drivers driven by a belt and a power pulley (not shown) by the motor assembly  25 . The motor assembly  25  also has a lower powered drive pulley  26  which operably powers cutting blades on the mower deck  6 , as will be discussed below. The mower  1  of the illustrated embodiment happens to be a zero radius turning mower in which each of the rear wheels  21  and  22  is driven by an independent hydraulic motor (not shown) which is in turn driven by the motor assembly  25 . A joystick  27  is mounted on the frame  5  and is located so as to be accessible by the operator to allow the operator to selectively control drive to each of the rear wheels  21 , thus controlling the direction and speed of the mower  1 . Mowers of the same general type are well known in the industry. While the mower  1  of the present invention happens to be a zero radius turning type mower and has hydraulic units associated with the wheels, it is foreseen that other types of mowers could readily be used in conjunction with the present invention.  
         [0027]     The mobile frame  5  also includes an operator seat  29  which allows an operator to be seated during operation of the mower  1  and to control the mower  1  via the joystick  27 .  
         [0028]     The mower deck  6  has a top wall  34  and a peripheral side wall  35  that depends from the top wall  34  except in the area of a chute (not shown) for allowing discharge grass therefrom. A middle front roller  38  and a pair of side front rollers  39  are mounted on the front or to the left of the mower deck  6 . A pair of rear side rollers  41  are mounted on the rear of the mower deck  6 . The rollers  38 ,  39  and  41  keep the deck  6  somewhat spaced from a ground surface that the deck  6  is traversing and helps prevent scalping of the grass whenever the deck  6  gets too close to the ground due to uneven terrain.  
         [0029]     Three cutting blades  44  are mounted on the underside of the mower deck  6  in a spaced relationship with one another and so that their cutting patterns overlap from front to rear in a manner that is well known in the art. Each of the cutting blades  44  is rotatably mounted on a shaft  45  which is in turn mounted on the deck top wall  34  and driven by a blade pulley  47 . As shown in  FIG. 8 , also rotatably mounted on top of the deck top wall  34  are three guide pulleys  49 ,  50  and  51 . A tension control pulley  54  is also mounted on the deck top wall  34  and is moveable along a path to selectively reduce or increase belt tension, as described below. As seen in  FIG. 10 , tension control pulley  54  is attached to a V-shaped lever arm  55  which is centrally pivoted about a pivot  56  located beneath the center of the pulley  51 . The lever arm  55  is in turn attached to a spring  57  that is in turn connected to a second V-shaped lever arm  58  which is in turn connected to an L-shaped lever arm  59  extending to an operator handle  60  and a fixed pivot  61  opposite the operator handle  60  so as to allow an operator to swing the lever arm  59  about the pivot  61  thereby also swinging the lever arm  58  about a pivot  62  whereat it is joined with the lever arm  59  so as to selectively position the tension control pulley  54 . Tension applying and tension releasing positions for the pulley  54  and associated mechanism are shown in  FIG. 10  in solid and phantom lines respectively.  
         [0030]     A drive belt  65  is reeved or looped about each of the pulleys  47 ,  49 ,  50 ,  51 ,  54  and the engine drive pulley  26  so as to provide drive power between the engine and the blade pulleys  47  so as to rotate the blades  44  when desired and when the tensioning pulley  54  is providing tension to the drive belt  65 . The drive belt  65  traverses a path that is generally planar except for slight variations due to raising or lowering of the mower deck  6 . In particular, the tensioning pulley  54  provides tension to the belt  65  when the operator handle  60  is in a first configuration thereof, as is shown in solid lines in  FIG. 10 . The operator handle  60  can be selectively moved to a second configuration, wherein the tensioning pulley  54  moves to the location shown by phantom lines in  FIG. 10  and which removes tension from the drive belt  65  and allows the drive belt  65  to be easily disconnected from the engine drive pulley  26  for manipulation from the mower deck  6 , as described below.  
         [0031]     A pair of shields  67  are also mounted on the mower deck top wall  34  in covering relationship to the outside blade pulleys  47  so as to reduce the possibility of an operator inadvertently getting caught between the drive belt  65  and the pulleys  47 .  
         [0032]     The support adjustment structure  7  supports the mower deck  6  relative on the mobile frame  5 , allows selective adjustment of the cutting height of the mower deck  6  during operation and provides for selective positioning of the mower deck  6  relative to the mobile frame  5  for purposes other than cutting of grass. The support and adjustment structure  7  includes a pair of front support arms  75  and a pair of rear support arms  76  and a height adjustment and release mechanism  79 .  
         [0033]     One of the pair of front support arms  75  is positioned on each side of the frame  5  and pivotally attached to an ear  82  within a respective channel  12  and  13 . The lower part of each front support arm  75  is pivotally attached by a connector assembly  83  that is secured to the mower deck top wall  34 . One of the pair of rear support arms  76  is located on opposite sides of the mobile frame  5  and are pivotally attached at an upper end thereof to respective ears  82  and at a lower end thereof to respective ears  86  mounted near the rear end of the deck top wall  34 . Each of the ears  86  has a rearwardly extending hook member  87  near the top thereof.  
         [0034]     Each of the rear support arms  76  has an upper section or portion  89  and a lower section or portion  90  which are joined at a pivot  91 . The rear support arm lower portions  90  are essentially the same length as the front support arms  75  and the rear support arm upper portions  89  are essentially the same length as the distance between the locations whereat the front support arms  75  join connector assemblies  83  and the rear support arms  76  join ears  86 . In this manner, a parallelogram-like structure is generally formed in conjunction with the arms  75 ,  76  and that portion of the deck top wall  34  that extends therebetween. However, the dimensions of the parallelogram-like structure can be varied somewhat as noted below. The rear support arm upper portion  89  is joined to the frame  5  only at the ear  82 ; however, each rear support arm upper portion  89  is designed to abut against the under surface of respective channels  12  and  13 , as is seen in  FIG. 2  during operation of the mower  1  during the cutting of grass or the like. In this manner, the mower deck  6  can swing about the front support arm  75  and rear support arm lower portion  90 , while being maintained in a generally parallel configuration with the frame channels  12  and  13 .  
         [0035]     Furthermore, when the mower deck  6  is detached from the height adjustment and release mechanism  79 , as will be discussed below, the frame  5  can be raised at the front thereof and the mower deck  6  can be swung downwardly and forwardly relative to the remainder of the frame  5 , as is seen in  FIG. 6  until the front support arm  75  and the rear support arm lower portions  90  become generally perpendicular to the frame channels  12  and  13 . Thereafter, the mower deck  6  can be swung still more forwardly near the rear thereof so as to rotate the rear arm upper portions  89  away from the channels  12  and  13 , as is seen in  FIG. 7  so as to expose the underside of the mower deck  6  to an operator to allow the operator to work on the mower cutting blades  44 , to clean the underside of the mower deck  6  or otherwise perform maintenance on the structure.  
         [0036]     In certain embodiments, it is foreseen that a pin, hook or other structure could be equivalently provided on the front support arm  75  or the rear support arm upper portion  89  to engage the opposite in such a way as to hold the upper portion  89  in a parallel configuration relative to the top of the deck  6  and in this way preform the same function as the engagement of the upper portion  89  with the frame  5  that is shown in the illustrated embodiment.  
         [0037]     The mower deck  6  preferably has a slightly over-center configuration when in the exposed configuration, as is also seen in  FIG. 7  wherein the rear support arms  76  are stretched outwardly and substantially in line relative to one another and the original rear, now bottom, of the mower deck  6  is slightly forward of the original front, now top, thereof, so as to form a stable exposed configuration to allow an operator to work on the device without easy collapse thereof.  
         [0038]     With reference to  FIG. 8 , the height adjustment and release mechanism  79  includes an elongate and laterally extending pivot rod  95  laterally mounted on and extending outwardly therefrom. Near opposite ends of the rod  95  are a pair of rigidly joined lever arms  98 . The lever arms  98  that each have an elongate slot  99  near the distal end thereof through which a capture rod or bail  102  is mounted so as to extend generally parallel to the rod  95 . A spring  104  is sleeved on each of the lever arms  98  and extends between the rod  95  and the rod  102  so as to urge the rod  102  outwardly relative within the slots  99 . A second spring  107  is mounted between each of the distal ends of the lever arms  98  and the frame floor plating  16  so as to cushion movement of the mechanism  79  at the capture rod  102 .  
         [0039]     Medially extending outwardly from the rod  95  between the lever arms  98  is an operator handle or arm  110  that is fixably attached to the rod  95  and rigidly extending therefrom above the frame floor plating  16  and in the region where the operator can access the handle  110  while in the seat  29 . A stop lever arm  113  also extends rigidly outward from the rod  95  near the channel  12 . The stop lever arm  113  is positioned so that swinging of the lever arm  113  by rotation of the rod  95  moves the lever arm  113  into abutting engagement with a stop pin  116  selectively located in receiver  117 . In this manner the rotation of the rod  95  is limited when the pin  116  is in the receiver  117  and the rod  95  free to rotate further when the pin  116  is removed from the receiver  117 . It is foreseen that in some embodiments the stop operably provided by the arm  113  engaging the pin  116  could be provided by other types of devices. For example, a slide, rotatable plate or the like could be operably placed under the handle  110  so as to engage the handle upon downward movement and wherein such device could be moved manually to allow an operator to further lower the handle  110 .  
         [0040]     Each connector assembly  83 , as is best seen in  FIG. 9  comprises an outer U-shaped member  120  and an inner U-shaped member  121 . The outer member  120  is fixedly attached by welding or the like to the mower deck top wall  34  and includes a pair of longitudinally extending slots  124  in each forward arm thereof. The inner U-shaped member  121  is slideable relative to the outer member  120  and each forward wall includes aligned bores  125  that also align with the slots  124  and receive a pin  127 . The bottom end of a respective arm  75  is positioned to be surrounded by the inner member  121  and has a bore  129  that also receives the pin  127 . A rear wall  130  of the inner member  121  also has attached thereto a bolt  132  that extends rearwardly and passes through a bore  134  in a rear wall  135  of the outer member  120 . A nut  137  allows adjustment of the position of the bolt  132  to slide the inner member  121  relative to the outer member  120  and thereby vary the angle of the front arms  75 . This allows height of the front sides of the mower deck  6  to be adjusted slightly, if some irregularity exists or to even raise the mower deck  6  front slightly relative to the rear thereof for certain cutting operations. It is foreseen that in some embodiments, a connector assembly  83  may be used to connect each of the rear support arms  76  to the deck  6  or, where the top of the arms  75  and  76  are independently joined to the frame  5 , then a connector assembly  83  could be utilized to connect either support arm  75  or  76  to the frame  5 .  
         [0041]     During use, the height adjustment and release mechanism  79  functions in the following way. When the pin  116  is located in the receiver  117 , the movement of the operator handle  110  rotates the rod  95  and swings the capture rod  102  about through a similar angle of rotation as is incurred by the operator handle  110  so as to move the mower deck  6  upwardly or downwardly as desired by the operator to adjust the cutting height of the mower deck  6 . Once the pin  116  is removed from the receiver  117 , the operator handle  110  can rotate the rod  95  so that the capture rod  102  moves rearwardly and downwardly and disengages from the hook members  87 . This frees the mowing deck  6  from the adjustment and release mechanism  79 . Further operation of the operator handle  60  associated with the tensioning pulley  54  releases tension on the tensioning pulley  54  so that the drive belt  65  can be released from the motor drive pulley  26  and thereby allow the mower deck  6  to be swung through the position shown in  FIGS. 6 and 7  to allow the mower deck to move from a mowing configuration thereof as seen in  FIG. 2  to a maintenance configuration thereof, as seen in  FIG. 7 . The processes reverse to move the mower deck  6  back into the mowing configuration thereof and the operator handle  60  is rotated again so that the capture rod  102  comes into engagement and is captured on the hook members  87  and thereafter for the rotation of the operator handle  60  raises the mowing deck  6  to a desired cutting level thereof.  
         [0042]     It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.