Abstract:
A seat assembly for an off-road vehicle includes a seat having a bottom surface, and a resilient seat suspension supporting the seat. The seat is supported at least in part by a first bumper element carried by the seat suspension. The first bumper element includes a protruding portion interposed between the seat bottom surface and the seat suspension, the protruding portion supporting a portion of the seat from the seat suspension. The seat suspension and the first bumper element are arranged to adjust a length of the protruding portion. The length of the protruding portion can be adjusted to set an elevation of the seat at the point of support by the first bumper element. The seat can also be adjustably connected to another part of the resilient seat suspension by use of a seat bracket with selectable holes to register with holes provided on the resilient seat suspension.

Description:
TECHNICAL FIELD OF THE INVENTION  
         [0001]    The present invention relates to seat suspension systems and more particularly to an improved seat suspension system having a mechanism for adjusting the vertical elevation and tilt of the seat.  
         BACKGROUND OF THE INVENTION  
         [0002]    It is known to provide seat suspension systems which dampen vertical seat movement in response to vehicle motion. It is also known and common to provide a fixed amount of vertical resiliency.  
           [0003]    In off-road vehicles such as lawn and garden tractors, one conventional seat suspension systems consists of two vertically arranged springs between the seat and tractor body for cushioning the force transmitted to an operator sitting in the seat.  
           [0004]    Operators of different heights or weights may desire vertical adjustment of the seat for comfortable riding. Some prior seat suspension systems are not adjustable or require tool adjustment of the seat height to accomplish this adjustment.  
           [0005]    The present inventor has recognized it would be desirable to provide a seat suspension system that was vertically adjustable with little or no need for tool adjustment.  
           [0006]    The present inventor has recognized that it would be desirable to provide an elastomer bumper that supports a portion of a seat, the elastomer bumper being adjustable in effective length by a simple manipulation without the necessity of tool adjustment.  
         SUMMARY OF THE INVENTION  
         [0007]    The invention provides a seat assembly for an off-road vehicle, wherein the height and/or angle of tilt of a driver&#39;s seat can be easily adjusted by the provision of at least a first elastomer bumper.  
           [0008]    According to one exemplary embodiment of the invention, the seat assembly includes a seat having a bottom surface, and a resilient seat suspension supporting the seat. The seat is supported at least in part by the first bumper element carried by the seat suspension. The first bumper element includes a protruding portion interposed between the seat bottom surface and the seat suspension, the protruding portion supporting a portion of the seat from the seat suspension. The seat suspension and the first bumper element are arranged to adjust a length of the protruding portion.  
           [0009]    The length of the protruding portion can be adjusted to set an elevation of the seat at the point of support by the first bumper element. The seat can also be adjustably connected to another part of the resilient seat suspension by use of a seat bracket with selectable holes to register with holes provided on the resilient seat suspension.  
           [0010]    The seat suspension can comprises an upper support plate. The upper support plate comprises a first elongated opening having a wide region and a narrow region, and the first bumper element comprises one or more grooves spaced apart along a length of the bumper element. The narrow region is shaped to receive the first bumper element therein with a select one of the grooves receiving portions of the upper support plate therein to fix the first bumper element to the upper support plate.  
           [0011]    The seat assembly can comprise a second bumper element identical to the first bumper element, and the upper support plate can comprise a second elongated opening identical to the first elongated opening. The first and second bumper elements can be arranged laterally spaced apart and fixed to the upper support plate.  
           [0012]    The seat suspension can include a baseplate and two springs arranged between the baseplate and the upper support plate. A front pair of links can be pivotally connected to the baseplate at a front end thereof and pivotally connected at a rear end thereof to the upper support plate. A rear pair of links can be pivotally connected at a front end thereof to the baseplate and at a rear end thereof to the upper support plate.  
           [0013]    The first and second bumper elements can each comprise a cylinder having one annular groove or plural spaced apart annular grooves, and the upper support plate can comprise elongated openings each having a first region sized to allow entrance of the cylinder vertically therethrough, and a second region open to the first region and having a width that prevents vertical entrance of the cylinder through the second region. The second region is of a width that accepts a width of the cylinder taken through the selected annular groove, to allow lateral sliding movement of the cylinder into the second region with wall portions of the upper support plate adjacent opposite sides of the second region entering a select one of the grooves. The width of the cylinder taken through the annular groove can be slightly greater than the width of the second region but can be resiliently compressed to fit within the second region to lock the cylinder to the upper support plate.  
           [0014]    Numerous other advantages and features of the present invention will be become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view of an off-road vehicle incorporating the seat suspension system of the present invention;  
         [0016]    [0016]FIG. 2 is an enlarged side view of the seat and seat suspension system of FIG. 1;  
         [0017]    [0017]FIG. 3 is a bottom perspective view, partially exploded, of the seat and seat suspension system of FIG. 2;  
         [0018]    [0018]FIG. 4 is an exploded perspective view of the seat and seat suspension system of FIG. 2;  
         [0019]    [0019]FIG. 5 is a plan view of a portion of the seat suspension system;  
         [0020]    [0020]FIG. 6 is a sectional view taken generally through line  6 - 6  of FIG. 5; and  
         [0021]    [0021]FIG. 7 is an elevational view of an alternate embodiment bumper.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.  
         [0023]    [0023]FIG. 1 illustrates an off-road vehicle  10 , such as a lawn tractor of a type such as JOHN DEERE lawn and garden tractor models 425, 445 or 455. The vehicle  10  includes a vehicle seat  14  supported on a seat suspension system  18  that is mounted on a vehicle body  19 .  
         [0024]    FIGS.  2 - 4  illustrate the seat  14  and the suspension system  18  in more detail. The suspension system includes a seat bracket  20 , a resilient suspension assembly  24 , and support channels  26 ,  27  connected by a crossmember  28  (FIG. 3). The seat bracket  20  is fastened to the seat  14  and to the suspension assembly  24  by a connecting rod  29 . The suspension assembly  24  is slidingly carried on the channels  26 ,  27  that are fastened to the vehicle body  19  via the crossmember  28  at a front side and by fasteners  30  at a rear side. A crossmember can also be used at the rear side if necessary to reinforce the connection to the vehicle body  19 .  
         [0025]    The seat bracket  20  includes a horizontal member  32  attached to a bottom of the seat  14  with fasteners, and two vertical attachment members  34 . The two vertical attachment members  34  each include attachment holes  36   a ,  36   b ,  36   c  arranged along an oblique line tilted rearward from the lowest hole  36   a  to the highest hole  36   c.    
         [0026]    The suspension assembly  24  includes an upper support plate  42  and a baseplate  46 . A pair of front links  50 ,  52 , angled rearward, connects a front portion of the baseplate  46  to the upper support plate  42 , via pivot rods  66 ,  68 .  
         [0027]    Two springs  70 ,  72  are carried on the baseplate  46  and support the pivot rod  68 , which effectively supports the upper support plate  42  that is connected to the pivot rod  68 . A suspension bumper  78  is carried by the baseplate  46  and located to the rear of the springs  70 ,  72 . In normal operation, when riding over smooth terrain, the upper support plate  42  is entirely supported by the springs  70 ,  72 . The suspension bumper  78  is impacted by the upper support plate  42  when the vehicle  10  experiences excessive seat amplitude, such as when the vehicle strikes an object or a hole, or rides over rough terrain.  
         [0028]    The upper support plate  42  includes holes  84 ,  86  that are registerable with a select one of the holes  36   a - 36   c  of each vertical member  34  to adjust the height of a front of the seat  14 . A connecting rod  92  is inserted through the selected pair of holes  36   a ,  36   a ;  36   b ,  36   b ; or  36   c ,  36   c  of the holes  36   a - 36   c  of the vertical members  34 ,  34  and the holes  84 ,  86  to connect the bracket  20  to the upper support plate  42 .  
         [0029]    A pair of rear links  94 ,  96 , angled rearward, connect a rear portion of the baseplate  46  to the rear portion of the upper support plate  42 , via connection by two pivot rods  98 ,  100 .  
         [0030]    The baseplate  46  is fastened to slide rails  106 ,  108  that are slidably engaged to the channels  26 ,  27 . Front elastomer bushings  110 ,  111  are arranged between the slide rails  106 ,  108  and the baseplate  46 . A lever  112  is operatively connected to a latching mechanism  116  that is used by an operator to select a relative sliding position of the rails  106 ,  108  on the channels  26 ,  27 . The latching mechanism has a prong  116   a  that is biased into a notch  116   b  in the respective rail  106 ,  108 , to engage a select one hole of a plurality of holes (not shown) arranged along the inside facing wall of the channel  26 .  
         [0031]    Two elastomer bumpers  120 ,  122  are carried by the upper support plate  42  and support a rear portion of the seat  14  from the upper support plate  42 , as described below with respect to FIGS. 5 and 6.  
         [0032]    [0032]FIGS. 2 and 4 also illustrate an operator presence switch  117  which is fit above a seat bottom wall  118  and below a plate spring  119 . When an operator compresses a seat cushion  14   a  of the seat  14  by sitting down, the plate spring flattens and actuates the presence switch  117 . When the operator leaves the seat, the plate spring  119  rebounds and the switch  117  is deactivated. The state of the switch  117  is used in vehicle safety controls.  
         [0033]    As illustrated in FIGS. 5 and 6, each bumper  120 ,  122  includes a cylindrical body  124  having two annular grooves  126 ,  128  spaced apart along a length of the body  124 .  
         [0034]    The upper support plate  42  includes two elongated openings  130 ,  132  each having a wide region  134  and a narrow region  136 . The wide region  134  can be circular and is large enough to vertically pass the cylindrical body  124  therethrough. The narrow region  136  is defined in part by wall portions  138 ,  140  that are spaced apart to resiliently enter a select one of the grooves  122 ,  124  to grippingly lock the cylindrical body  124  to the upper support plate  42 . The selected grooves  122 ,  124  set the vertical extension P of the cylindrical body with respect to the upper support plate  42 .  
         [0035]    [0035]FIGS. 5 and 6 illustrate the elastomer bumper  120  fixed to the upper support plate  42  at the opening  130 . The configuration of bumper  122  and the opening  132  is identical. As illustrated, the bumper  120  is set at one of several available vertical extensions P by the engagement of the annular groove  126  to the upper support plate portions  138 ,  140 . The uncompressed diameter d1 of the bumper  120  inside each of the grooves  126 ,  128  is slightly larger than the width d2 of the narrow region  136 . The bumper  120  includes an axial bore or channel  150  that allows for radial compression of the bumper body  124  within the grooves  126 ,  128 . This compression provides a resilient gripping of the bumper  120  by the upper support plate  42 .  
         [0036]    Several vertical extensions P are theoretically available depending on the groove  126 ,  128  selected to be engaged by the upper support plate  42  and the selected orientation of the bumper body  124 , i.e., the orientation selected between top side up as shown or inverted to top side down.  
         [0037]    According to an exemplary embodiment of the invention, the elastomer bumpers  120 ,  122  are composed of polyisoprene having a durometer of 65. The overall diameter of each of the bumpers  120 ,  122  can be about 32 mm. The uncompressed groove diameter d1 can be about 22 mm. The top groove  126  can be a distance g1 of about 6.5 mm from a top side  154  of the bumper and a distance g2 of about 36.5 mm from a bottom side  156  of the bumper. The lower groove  128  can be a distance g3 of about 21.5 mm from the bottom side  156  of the bumper and a distance g4 of about 21.5 mm from the topside  154  of the bumper. The grooves can have a height g5 of about 3.2 mm. The bore  150  can have a diameter d3 of about 6.5-9.5 mm.  
         [0038]    Along with the selected hole pairs of the holes  36   a - 36   c  of the vertical members  34 ,  34 , the selection of the groove  122 ,  124  and/or the orientation of the bumpers  120 ,  122  sets both the vertical height and the angular tilt of the seat  14 . According to an exemplary embodiment of the invention, two grooves  122 ,  124  are used on the bumpers  120 ,  122 . However, a single groove or more than two grooves could be used and are encompassed by the invention. Furthermore, although the exemplary embodiment includes three adjustment holes  36   a - 36   c , more or fewer adjustment holes could be used and such is encompassed by the invention. According to the exemplary embodiment using three holes  36   a - 36   c  and two grooves  122 ,  124 , the seat can be adjusted over approximately a one inch vertical range. The seat can also be adjusted over a {fraction (1/2)} inch horizontal range due to the oblique arrangement of the holes  36   a - 36   c.    
         [0039]    [0039]FIG. 7 illustrates an alternate embodiment bumper  160  which can replace, in a pair of bumpers  160 ,  160 , the previously described bumpers  120 ,  122 . The bumper  160  is cylindrical and has an overall length of about 52 mm and an overall diameter of about 32 mm. The bumper includes one annular groove  162  having a height h1 of about 3.2 mm and an uncompressed inside diameter d1 of about 22 mm. The distance h2 from a top side  166  of the bumper  160  and the groove is about 36.5 mm. The distance h3 between the groove and a bottom side  168  of the bumper  160  is about 12.5 mm.  
         [0040]    The bumper  160  of FIG. 7 can be installed as shown in FIG. 6 to provide an extension P equal to the distance h2 or inverted and reinstall to provide an extension P equal to the distance h3.  
         [0041]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.