Abstract:
A hinge assembly hingedly connects a first mower frame member defining a first frame hole to a second mower frame member defining a second frame hole, wherein at least one of the first and second frame members is a frame member of a mower deck of the mower. The hinge assembly comprises a first bushing having a first bushing hole and a first bushing axis, being sized for press fit receipt in the first frame hole, and being sized to rotatably coaxially receive a pin therein; a second bushing having a second bushing hole and a second bushing axis, being sized for axially non-rotating receipt in the second frame hole, and being sized to rotatably coaxially receive a pin therein; a pin having inboard and outboard ends and a pin axis, the pin sized to extend coaxially through the first and second bushing holes; a connector connected to the outboard end of the pin and for connecting the pin to the second frame member and holding the pin against horizontal movement relative to the second frame member and for providing a stop for limiting movement of the second bushing toward the outboard end of the pin; and, a retention member connected proximal to the inboard end of the pin and limiting movement of the bushings inwardly of the retention member.

Description:
REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation of my prior application, Ser. No. 10/200,838, filed on Jul. 19, 2002. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to the field of lawn mowers, and more particularly, to hinge systems for interconnecting articulating lawn mower decks.  
         BACKGROUND OF THE INVENTION  
         [0003]    To decrease the amount of time needed for cutting large areas of grass, mowers with multiple blades providing greatly increased cutting widths were designed. But because the world of grass is not flat, the cut was usually uneven and patches of grass were often scalped. Mounting the blades in individual mower decks and articulating the decks—that is, hingedly connecting the decks to one another—permitted the multiple deck mower to more closely follow the contour of the grass being cut. Over time, and especially in commercial applications of such articulating deck mowers, such as on golf courses, the constant articulation caused the hinge pins connecting adjacent decks to wear down. Replacement of the pins can be a time consuming, multi-step process, requiring the decks to be disassembled.  
           [0004]    What is needed is a hinge system that resists wear and facilitates servicing and replacement.  
         SUMMARY OF THE INVENTION  
         [0005]    Generally speaking, a hinge system is provided that resists wear and facilitates servicing and replacement. The hinge system include a front and a rear hinge assembly that hingedly connects a first mower deck to a second mower deck or a first mower deck to a portion of the mower that is not a mower deck.  
           [0006]    A hinge assembly hingedly connects a first mower frame member defining a first frame hole to a second mower frame member defining a second frame hole, wherein at least one of the first and second frame members is a frame member of a mower deck of the mower. The hinge assembly comprises a first bushing having a first bushing hole and a first bushing axis, being sized for press fit receipt in the first frame hole, and being sized to rotatably coaxially receive a pin therein; a second bushing having a second bushing hole and a second bushing axis, being sized for axially non-rotating receipt in the second frame hole, and being sized to rotatably coaxially receive a pin therein; a pin having inboard and outboard ends and a pin axis, the pin sized to extend coaxially through the first and second bushing holes; a connector connected to the outboard end of the pin and for connecting the pin to the second frame member and holding the pin against horizontal movement relative to the second frame member and for providing a stop for limiting movement of the second bushing toward the outboard end of the pin; and, a retention member connected proximal to the inboard end of the pin and limiting movement of the bushings inwardly of the retention member.  
           [0007]    It is an object of the present invention to provide an improved hinge system for articulating mower decks.  
           [0008]    Further objects and advantages will become apparent from the following description of the preferred embodiment.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a front, perspective view of a lawn mower  10  incorporating a hinge system for hingedly connecting the articulating mower decks in accordance with the present invention.  
         [0010]    [0010]FIG. 2 is a front, perspective view of the mower decks  11 - 14  of the lawn mower  10  of FIG. 1.  
         [0011]    [0011]FIG. 3 is an exploded, perspective view of a hinge assembly  22  of the hinge system  17  for hingedly interconnecting decks  12  and  13  of the lawn mower  10  of FIG. 1.  
         [0012]    [0012]FIG. 4 is a perspective view of the hinge assembly  22  of FIG. 3 and shown in the assembled condition.  
         [0013]    [0013]FIG. 5 is an end view of the hinge assembly  22  of FIG. 4.  
         [0014]    [0014]FIG. 6 is a side, cross-sectional view of the hinge assembly  22  of FIG. 5 taken along the lines  6 - 6  and viewed in the direction of the arrows.  
         [0015]    [0015]FIG. 7 is a perspective view of the pin assembly  34  of FIG. 6.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment 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 of the invention is thereby intended, and that any alterations or modifications in the illustrated device, and any further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0017]    Referring to FIGS. 1-3, there is shown a lawn mower  10  having articulating decks  11 - 14  and hinge systems  16 - 18  for interconnecting each adjacent pair of mower decks  11 - 12 ,  12 - 13 , and  13 - 14 , respectively. Each hinge system  16 - 18  includes a pair of hinge assemblies operable to allow one deck to pivot about an axis relative to an adjacent deck. Only the forward hinge assemblies  21 - 23  for each hinge system  16 - 18 , respectively, are shown in FIG. 1, at the front side of the decks. The companion, rear hinge assemblies for each forward hinge assembly  21 - 23  hingedly interconnect their decks at the opposing, rear and unshown sides of the decks. Only one hinge assembly  22  will be described herein, it being understood that the other two forward hinge assemblies  21  and  23  and the three rear, unshown companion hinge assemblies each includes the same components and each interconnects its pair of decks in the same manner as hinge assembly  22 , except where otherwise indicated.  
         [0018]    Referring to FIGS. 3-7, the outer frame of deck  10  extends laterally at frame extension  26  toward deck  11 . Frame extension  26  (a frame member of deck  10 ) has defined therein an upper, limit hole  27  and a lower, hinge hole  28 . Deck  11  includes a forward frame panel  29  and an angle bracket  30  that is fixed to panel  29  by any appropriate means such as welding. Panel  29  and bracket  30  (both frame members of deck  11 ) together define a slot  31  into which frame extension  26  is received when decks  10  and  11  are brought together.  
         [0019]    Hinge assembly  22  includes a pin assembly  34 , an anti-rotation bushing  35 , a spacer  36 , a main bushing  37 , a retention ring  38 , and a shaped hole  39  that is defined in bracket  30 . Pin assembly  34  (FIG. 6) includes a hinge pin  42  and a pin mount  43  that is fixedly connected to pin  42  by any appropriate means such as welding. In alternative embodiments, mount  43  may be removably connected to pin  42  by any appropriate means such as threading. Pin  42  is generally a rod made of die hardened chrome to reduce wear, but other compositions of pin  42  are contemplated. Pin  42  has defined therein three circumferential recesses  44 ,  45  and  46 . Recess  44  is actually a circumferential weldment groove  44  located near the outboard end  48  of pin  42 . Weldment applied at the juncture of pin mount  43  and pin  42  at groove  44  lodges partially within groove  44 , which provides a stronger bond between pin  42  and mount  43 , especially as mount  43  is pulled away from the decks, as will be described herein. The outboard end  48  includes the outermost face or surface of pin  42  (as directly indicated at  48  in FIG. 6) as well as a portion of pin  42  proximal the outermost face or surface of pin  42 . Opposite outboard end  48  is inboard end  49 , which likewise includes not only the innermost surface or face (as directly indicated at  49 ), but also a portion of pin  42  proximal the innermost surface or face of pin  42 .  
         [0020]    Recesses  45  and  46  are located closer to the inboard end  49 , as shown in FIG. 6. Recess  45  is actually an annular grease channel  45 , and recess  46  is actually a circumferential retention pin slot  46 . A central passageway  50  is defined to extend from outboard end  48  and approximately to channel  45  where a radial passageway  51  extends to provide fluid communication between central passageway  50  and channel  45 . A grease fitting  53  is secured to outboard end  48  and in communication with central passageway  50  to permit the injection of grease from fitting  53  to channel  45 . A cylindrical collar  54  is secured to the end of pin  42  by any appropriate means, such as welding, to protect grease fitting  53  from debris and damage.  
         [0021]    Pin mount  43  includes a central opening  56 , a bolt mounting hole  57 , and a pair of opposing, threaded thrust holes  58  and  59 . Main bushing  37  is made of oil impregnated powered metal and is sized externally for a press fit into hinge hole  28 . The internal diameter of bushing  37  is set to be just slightly larger than the outer diameter of pin  42  to permit pin  42  to rotate freely within bushing  37 . The axial length of bushing  37  is substantially equal to the thickness of frame extension  26 , as shown in FIG. 6.  
         [0022]    Like main bushing  37 , anti-rotation bushing  35  has an inner diameter that is just slightly larger than the outer diameter of pin  42  so that pin  42  may rotate freely within bushing  35 . However, in assembly as shown in FIG. 6 and during operation, both pin  42  and bushing  35  are constrained from rotating relative to angle bracket  30 , and consequently, pin  42  does not rotate relative to bushing  35 . That is, similar to a standard nut, the outer surface  60  of anti-rotation bushing  35  is hexagonally shaped. Shaped hole  39  is likewise hexagonally sized and shaped to snugly and matingly receive anti-rotation bushing  35  whereby bushing  35  is prevented from rotating relative to bracket  30  while it disposed within hole  39 . Anti-rotation bushing  35  has an axial length that is either equal to or greater than the thickness of angle bracket  30 . In the embodiment shown in FIGS. 1-6, the axial length of anti-rotation bushing  35  is greater than the thickness of angle bracket  30  to accommodate a spacer plate  62  that is interposed between pin mount  43  and angle bracket  30 . Spacer plate  62  has a shaped hole  63  that is identically sized and shaped to align with shaped hole  39  and to likewise snugly and matingly receive anti-rotation bushing  35 . Spacer plate  62  also defines a bolt mounting hole  64  that will align with bolt mounting hole  57  of pin mount  43  when shaped holes  39  and  63  are aligned, as shown in FIGS. 3 and 6. The axial length of anti-rotation bushing  35  is equal to the combined thickness of angle bracket  30  and spacer plate  62 . If no spacer plate  62  is not used, then the axial length of anti-rotation bushing  35  will be substantially equal to the thickness of angle bracket  30 .  
         [0023]    In the assembled condition shown in FIG. 6, spacer  36  is a ring that surrounds pin  42  between anti-rotation bushing  35  and main bushing  37 . Spacer  36  has an axial length designed to position main bushing  35  in the proper position along pin  42  whereby, when frame extension  26  is properly positioned within slot  31  of deck  11 , anti-rotation bushing  35  and main bushing  37  will both be properly aligned within their respective openings ( 63  and  39  and  28 ), as shown in FIG. 6. Retention ring  38  is secured within retention ring slot  46  to limit the inward movement of main bushing  37  beyond slot  46 . Retention ring  38  is a coil retention ring and permits slight radial expansion and assembly onto pin  42 . Alternatively, retention ring  38  may comprise other configurations or structure, such as a C-clip, so long as it may be applied to and/or used with pin  42  to limit the inward movement of main bushing  37  beyond the desired point. Frame panel  29  defines a hole  66  that is aligned with shaped hole  39  of angle bracket  30  so that when pin assembly  34  is inserted, the inboard end  49  of pin  42  will pass through hole  66  for support.  
         [0024]    In assembly, anti-rotation bushing  35 , spacer  36  and main bushing  37  are telescopically positioned onto pin  42 , up against the inward surface of pin mount  43  and in the order shown. Retention ring  46  is secured in retention ring slot  46  to hold bushing  35 , spacer  36  and bushing  37  in position. With decks  10  and  11  positioned to properly position frame extension  26  within slot  31  so that shaped hole  39  axially aligns with hinge hole  28 , the inboard end of pin assembly  34  is inserted through the aligned holes  63 ,  39  and  28  until main bushing  37  reaches hinge hole  28 . Because hole  28  and bushing  37  are sized for a press fit, bushing  37  will not easily enter hole  28 , and additional force such as by a mallet must be applied to the outboard side of pin assembly  34 . After several blows have been applied, main bushing  37  will have been forced into hinge hole  28 . As pin assembly is being struck and bushing  37  is forcibly moved into hinge hole  28 , anti-rotation bushing  35  will approach shaped holes  63  and  39 . The assembler will manually rotate anti-rotation bushing  35 , as necessary, at the start of entry of bushing  35  into its mating, shaped hole  63  (or at the start of entry into shaped hole  39  if spacer plate  62  is not included). Thereafter, anti-rotation bushing  35  will slide easily into shaped holes  63  and  39 . Likewise, as pin assembly  34  advances into holes  63 ,  39  and  28 , the assembler will rotate pin mount  43 , as necessary, to align bolt mounting hole  57  with mating, bolt mounting hole  64  and threaded bolt mounting hole  68  (or just mating threaded bolt mounting hole  68  if spacer plate  62  is not present). A bolt  70  is inserted through a bolt locking tab  72  and then through holes  57  and  64  and then threadedly through hole  68  until tight.  
         [0025]    Bolt locking tab  72  is a flat metal member with a central hole  73  for receiving bolt  70 . Extending radially outward from hole  73  are a plurality of bendable tabs. In the embodiment of FIG. 5, there are three tabs  75 - 77 , and the angle formed between two adjacent tabs is not equal to the angle formed between a different two adjacent tabs. For example, tabs  76  and  77  are about 90° apart, while the angle formed between tabs  75  and  76  is about 65°. When bolt  70  is tightened as desired, tab  77  is bent down and flat against flat side edge  80  of pin mount  43 , and at least one of the tabs  75  and  76  should be in a position to bend up and flat against one of the six side faces of hexagonal bolt head  78 . If one of the tabs  75  and  76  is not sufficiently aligned with one of the six side edges, then bolt  70  need be backed out or tightened no more than about 30° to align one of tabs  75  and  76  with a side edge of hexagonal head  78 .  
         [0026]    With the tabs bent as described, bolt  70  is held firmly in place and restrained from backing out. Alternative elements may be employed to restrain or lock bolt  70  from backing out, including but not limited to lock washers, Loctite adhesive, and a wire retainer tied through a hole in the head of the bolt. Whatever element is used, it should be able to hold the bolt in place, preferably until it is intentionally and manually removed, despite the often severe vibration to which it is subjected from the mower action. Alternative elements are contemplated to connect pin mount  43  to the mower frame member including, but not limited to, one or more screws, clamps, clips, hasps or other mechanical configurations that securely hold pin mount  43  to angle bracket  30  or similar mower frame element, as necessary to hold pin  42  in place for its intended operation, and where such element may be unfastened with little difficulty to release pin mount  43  from its secure connection to the mower frame element. Alternative configurations are contemplated for securely mounting pin  42  to pin mount  43  including, a threaded connection between pin  42  and pin mount  43 , an insert and twist key-hole type connection between pin  42  and pin mount  43 , alternative elements such as brackets connected separately to both pin  42  and pin mount  43 , and any other configuration that securely connects pin  42  with pin mount  43 , either permanently or removably.  
         [0027]    Eventually, pin  42 , one or more of the bushings, other of the hinge assembly elements, or other parts of the mower will require hinge assembly  22  (or one of the other hinge assemblies) to be disassembled. This is accomplished by first bending back the tabs of bolt locking tab  72  and removing bolt  70 . Then, a pair of thrust bolts  91  and  92  are inserted into threaded thrust holes  58  and  59  and advanced until their leading ends contact spacer plate  62  (or angle bracket  30  if a thrust plate is not used). Alternatively, each thrust bolt  91  and  92  is then advanced a small increment (e.g. a quarter turn). As the leading ends of the thrust bolts bear against spacer plate  62  (or angle bracket  30 ), pin mount  43  is forcibly backed away from spacer plate  62  and angle bracket  30 , which by virtue of retention ring  38 , pulls anti-rotation bushing  35  and spacer  36  therewith and, most importantly, pulls main bushing  37  out of its press fit position within hinge hole  28 .  
         [0028]    Angle bracket  30  defines a threaded hole  83  (FIG. 6) that, when decks  10  and  11  are hingedly connected by pin assembly  34 , aligns with limit hole  27  of frame extension  26 . A bolt  84  is threadedly received within hole  83  and extends into oversized hole  27 . The clearance  85  provided between bolt  84  and hole  27  permits deck  11  to pivot about the axis of pin  42  (and its companion pin, which is not shown, but hingedly connects decks  10  and  11  at the rear side of the decks). The difference in diameter between the shank of bolt  84  and hole  27  defines the degree of articulation (hinged movement) about the corresponding hinge pins  42 . This bolt and oversized hole combination that governs the limits of deck articulation is provided at hinge systems  16  and  17 , but not at hinge system  18 . The limits of articulation between decks  13  and  14  is provided by a deck pivoting system  88  that controls the angle of pivot of deck  14  relative to deck  13 , which includes deck  13  pivoting up approximately 90 degrees for a narrower mowing width and for transport.  
         [0029]    The present invention has been described as including pin assemblies for hingedly connecting articulating mower decks to one another. Alternative embodiments are contemplated wherein one or more pin assemblies may hingedly connect a mower deck to a portion of the mower that is not a mower deck, but may instead be a section of the mower frame. The present invention shows the shaped hexagonal holes  39  and  63  as being on the angle bracket  30 . Alternative embodiments contemplate other shapes of holes  39  (and hole  63  if a spacer plate  62  is used) and include other manners of making bushing  35  non-rotational. For example, alternative embodiments contemplate bushing  35  having a round outer shape and being press fit into its hole to preclude rotation. Other embodiments contemplate bushing  35  being permitted to rotate within its corresponding hole. Other embodiments contemplate the shaped hole  39  being located in the frame extension  26 , or in either one of a first mating mower deck and a second mower deck or mower structure. Alternative embodiments are contemplated wherein spacer  36  is replaced by having one or both of bushings  35  and  37  having a greater in axially length or similarly modified in any appropriate manner to achieve the desired spacing among the corresponding components.  
         [0030]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrated and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.