Abstract:
A rear deck service ladder for combine harvesters having rear M.O.G. discharge ports, said ladders being retractable and extendible without interfering with the discharge port.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to devices and methods for accessing the engine servicing platforms of combine harvesters, and it particularly relates to platform ladders and methods for using such ladders at the rear of a combine. 
       BACKGROUND ART 
       [0002]    A variety of different ladders are presently known to provide access between the ground and the engine service platform of a combine. Folding ladders incorporating spring biased over-centering linkages to hold the ladders in stowed or closed positions without the need of a separate latching mechanism, have been known since 1978 from U.S. Pat. No. 4,131,293 by Kindle. However, typical ladders for combines remain relatively short, on the order of three to five steps, and typically the ladders simply swing or pivot from deployed position into a position for storage. Additionally, several folding step arrangements are in the prior art. Also ladders that fold into or against a vehicle body are known, and there are known embodiments utilizing tracks to align a ladder into a storage hold. 
         [0003]    However, there are certain recent model combines which have functional drawbacks inhibiting the deployment of ladders at the extreme rear end of the combine. Principally, among these drawbacks, is the difficulty of accommodating the discharge of straw and other M.O.G. (material other than grain) at the rear of the combine. That is, the ladder must be stored while also allowing ample room for the discharging straw and M.O.G. to flow freely, without being obstructed by the ladder. For purposes of homologation, the ladder, when deployed, must be long enough to extend beyond the discharge opening. Also prior art ladders do not accommodate variations in vehicle height resulting from variation in the tire package. Furthermore, the ladders, when in the storage position at the rear, will accumulate straw and M.O.G. discharge, which subsequently spills onto the operator when he manually deploys the ladder into the service position. 
         [0004]    An access device or ladder, and a method for storing and deploying same while overcoming the above-described drawbacks, would provide an unexpected advancement in combine harvester design, while satisfying a longfelt need for accessing combine harvester engine service platforms, when there is a discharge port located at the rear of the combine, which location heretofore necessitated having the access ladders on the right-hand side of the combine service platform, rather than at the rear. 
       SUMMARY OF THE INVENTION 
       [0005]    The above-described drawbacks and others which will be apparent to those skilled in the art are overcome by the access ladder and method of the present invention which embodies a ladder having a smaller portion that flips up at the bottom of the ladder, which bottom portion of the ladder connects to adjustable trim panel on the combine allowing cooperation with variations in vehicle height and width. The trim panels enable the ladder&#39;s deployment from machines of varying height or width without the need to modify the individual ladder or platform assembly. The ladder also has an upper portion which, in the storage position, allows the ladder to be in the same plane as the hand railing on the engine servicing platform, but which upper portion slides both vertically and rearwardly, along tracks, when deployed, without the necessity of spring-biased linkages for holding the ladder in a stowed or closed position. The upper portion is connected to contoured lower support arms that wrap around the straw and M.O.G. discharge door, which support arms neck into a narrow position, but allowing the deployed ladder to clear the discharge door for the straw and M.O.G. discharge port. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a left side elevation of the rear of a combine incorporating the present invention; 
           [0007]      FIG. 2  is a perspective view of a prior art combine having its access ladder on the right-hand side of the combine; 
           [0008]      FIG. 3  is a perspective view of a combine showing the rear access ladder of the present invention in its stored position; 
           [0009]      FIG. 4  is a left side view of an engine service platform embodying the rear access ladder of the present invention in its stored position; 
           [0010]      FIG. 5  is a left side view of an engine service platform embodying the rear access ladder of the present invention, said ladder being deployed halfway but prior to unfolding its bottom portion; 
           [0011]      FIG. 6  shows a left side view of an engine service platform embodying the rear access ladder of the present invention being fully deployed downward but without unfolding its lower portion; 
           [0012]      FIG. 7  is a perspective view of an engine service platform embodying the rear access ladder of the present invention being fully deployed and having its lower portion unfolded; and 
           [0013]      FIG. 8  illustrates a rear elevational view of a combine including its engine service platform embodying the rear access ladder of the present invention in its fully stored position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    Referring generally to the accompanying drawings, the invention disclosed herein can be illustrated on an agricultural vehicle such as the combine shown generally as  10 . The combine will typically include a chassis or body  12  having vertical side walls  14 . The body  12  is supported on a pair of large driven wheels  16  at the front of the combine  10  and a pair of wheels  20  at the rear thereof. An operator&#39;s platform  32  and cab  50 , a crop gathering header (not shown), a feeder  26  and a grain delivery chute  80  are conventional. An engine service and access platform or catwalk  32  having guardrails  34  is provided at the rear end  36  of the combine. Referring to  FIG. 2 , the rear access ladder  40  of the present invention is integrally stored in upright fashion on the rear access platform  32  so as to define a movable extension of the handrails  34 . This configuration is in contrast to the prior art access ladder  400  configuration as shown in  FIG. 2  which is located on the right-hand side (as opposed to being located at the rear) of the engine service platform  32  and when stored merely swings into the up position and swings into the down position when deployed. 
         [0015]    Referring to  FIGS. 4 ,  5  and  6 , the drawings progress from  FIG. 4  where the rear access ladder  40  of the platform  32  is fully stowed away, to  FIG. 5  where the ladder  40  is partially deployed into service, to  FIG. 6  where the ladder  40  is more advanced into service, and onto  FIG. 7  where ladder  40  is fully deployed and unfolded. Ladder  40  comprises two hinged portions  41  and  42 . Ladder portion  41  defines a longer upper portion of ladder  40 , which portion  41  is slidingly engaged at its top end  44  to up and down along two rails of handrails  34 . Trim panel attachments  51  and  52  attach to the uprights  45  and  46  respectively of the ladder lower portion  42 . These trim panel connections allow the majority of the trim panels of varying width machines to remain the same while the panel&#39;s width changes to accommodate varying widths. Lower support arms  60  and  61  are contoured to wrap around straw door opening  70  as shown in  FIG. 8 . 
         [0016]    It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.