Abstract:
An agricultural harvesting machine that comprises a crop processing mechanism and an elevator assembly for conveying harvested crop material to the crop processing mechanism is provided. The elevator assembly comprises an elevator housing, an elevator mechanism mounted in the housing, at least two flexible endless members and a plurality of slats mounted transversely to the flexible members. The slats have an S-shaped cross section that provides additional strength to the slats while reducing the chance of damage to the crop conveyed by these slats.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This patent application is a Divisional of, and claims priority to under 35 U.S.C. §120, U.S. patent application Ser. No. 10/476,273, filed on Oct. 27, 2003, now U.S. Pat. No. 6,922,983, entitled, “Elevator Slats For An Agricultural Harvesting Machine” and having Jose G. T. Gryspeerdt as the Inventor. The full disclosure of U.S. patent application Ser. No. 10/476,273 is hereby fully incorporated by reference. 

   FIELD OF INVENTION 
   The present invention relates to an elevator for an agricultural harvesting machine which is equipped for collecting crop material from a field and processing the same. In particular, it relates to the elevator which conveys the collected crop to the crop processing mechanism and slats used in such elevator. 
   BACKGROUND OF INVENTION 
   Agricultural harvesting machines such as combine harvesters generally are developed to handle a large variety of crops. For example a combine harvester may be used to harvest small grain crops such as wheat and rye, rape or grass seed or large grain crops such as peas or corn. In this manner the use of the harvester, which is a high investment tool, can be extended over a longer season. 
   Conventionally the harvester is equipped with a detachable crop collecting attachment, such as a grain or corn header, which cuts the stems of the crop standing in the field and conveys the same to the inlet of an elevator housing. Alternatively crop which has been cut previously can be lifted up from the field by a pick-up attachment and conveyed to the same inlet. Elevator mechanism, commonly a chain elevator with transverse slats, grab the collected crop deposited in front of the inlet and convey it rearwardly and upwardly towards the crop processing mechanism, conventionally a threshing drum and concave or grate assembly. 
   The transverse slats of the elevator can be made out of angled steel profiles. However, because of the increasing capacity of modern harvesters, these slats are subject to increasing loads which may result in a permanent deformation of the slats. To increase their strength, the slats may be made out of more complicated profiles such as a U- or V-shaped profile as shown in U.S. Pat. Nos. 4,369,617 and 5,346,429. However it has been experienced that near the outlet of the elevator the trailing edge of the slats may notch the corn grains in the ears, thereby seriously reducing their capacity for storage. Hence there is a need for a sturdy slat which does not damage the kernels. 
   SUMMARY OF INVENTION 
   According to one aspect of the present invention there is provided an agricultural harvesting machine comprising crop processing mechanism and an elevator assembly for conveying harvested crop material to said crop processing mechanism, the elevator assembly is comprised of an elevator housing and elevator mechansim in said housing and comprising at least two fleible endless members and a plurality of slats mounted transversely to said flexible members.
         wherein said slats have an S-shaped cross section.       

   This particular shape provides additional strength to the slats, while the reinforcing portions do not damage the harvested crop material. 
   According to a further aspect of the present invention there is provided a method for making slats with an S-shaped cross section, including the steps of cutting flat slats of steel plate; using a compound rolling process for providing the flat slats with an S-shaped cross section; and cutting the profiled slats to length. 
   This compound rolling process may equally comprise the step of providing an edge of said flat slats with notches. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     An agricultural harvester in accordance with the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings in which: 
       FIG. 1  is a diagrammatic, partly sectional side view of a combine harvester having a forwardly extending straw elevator; 
       FIG. 2  is cross sectional view of the straw elevator of  FIG. 1 ; 
       FIG. 3  is an enlarged cross sectional view of the rear end of the straw elevator; 
       FIG. 4  is a side view of an elevator slat for use in the straw elevator of  FIG. 2 ; and 
       FIGS. 5 and 6  are bottom and rear views of the slat of  FIG. 4 , taken in the direction of arrows V and VI, respectively. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The terms “grain”, “straw” and “tailings” are used principally throughout this specification for convenience but it is to be understood that these terms are not intended to be limiting. Thus “grain” refers to that part of the crop material which is threshed and separated from the discardable part of the crop material which is referred to as “straw”. Incompletely threshed crop material is referred to as “tailings”. Also the terms “forward”, “rearward”, “left” and “right”, when used in connection with the combine harvester and/or components thereof are usually determined with reference to the direction of forward operative travel of the combine harvester, but again, they should not be construed as limiting. The terms “longitudinal” and “transverse” are determined with reference to the fore-and-aft direction of the harvester and are equally not to be construed as limiting. 
   The combine harvester  10  shown in  FIG. 1  of the accompanying drawings, is of the axial-flow type, wherein crop material is threshed and separated while it is advanced by and along a longitudinally arranged rotor  27 . The combine harvester comprises a chassis or main frame  11  having a pair of driven, ground-engaging front wheels  12  and a pair of smaller, steerable rear wheels  13 . Supported on the main frame  11  are an operator&#39;s platform  14  with an operator&#39;s cab  15 , a threshing and separating assembly  16 , a grain cleaning assembly  17 , a grain tank  18  and a power plant or engine  19 . A conventional grain header  22  and a straw elevator assembly  23  extend forwardly of the main chassis  11  and are pivotally secured thereto for generally vertical movement which is controlled by appropriate actuators, such as hydraulic cylinders (not shown). 
   As the combine harvester  10  is propelled forwardly over a field with standing crop, the latter is severed from the stubble by a sickle bar  24  at the front of the header  22  and delivered by a header auger  25  to the inlet of the straw elevator assembly  23 , which supplies the cut crop to the threshing and separating assembly  16 . 
   The threshing and separating assembly  16  comprises a generally cylindrical chamber  26  in which a rotor  27  is rotated to thresh and separate the crop received therein, that is to say, the crop is rubbed and beaten between the rotors  27  and the inner surfaces of the chambers  26 , whereby the grain, seed or the like, is loosened and separated from the straw. 
   Grain which has been separated by the threshing and separating assembly  16  falls onto a first grain pan  30  of the cleaning assembly  17  which further also comprises a pre-cleaning sieve  31 , positioned above a second grain pan  32 , a pair of sieves  33 ,  34 , disposed the one above the other, and a cleaning fan  35 . The grain pans  30 ,  32  and the sieves  31 ,  33 ,  34  are oscillated generally back-and-forth for transporting threshed and separated grain from the first grain pan  30  to the pre-cleaning sieve  31  and the second grain pan  32  and therefrom to the sieves  33 ,  34 . The same oscillatory movement spreads said grain across said sieves  31 ,  33 ,  34 , while permitting the passage of cleaned grain by gravity through the apertures of these sieves. The grain on the sieves  31 ,  33 ,  34  is subjected to a cleaning action by the fan  35  which provides an air flow through said sieves to remove chaff and other impurities such as dust from the grain by making this material airborne for discharge from the machine through an outlet  37  of the straw hood  38 . 
   Clean grain falls to a clean grain auger  40  in a clean grain auger trough  41  and is subsequently transferred therefrom by a grain elevator  44  to the grain tank  18 . Tailings fall to a tailings auger (not shown) in a tailings auger trough  42 . The tailings are transported sideways by said tailings auger to a separate rethresher  43  and returned by a tailings conveyor  45  to the cleaning assembly  17  for repeated cleaning action. 
   A pair of grain tank augers  46  at the bottom of the grain tank  18  is used to urge the clean grain sideways to an unloading tube  47  for discharge from the combine harvester  10 . 
   As shown in greater detail in  FIG. 2 , the straw elevator assembly  23  comprises a welded, substantially parallelepiped housing  50  which is pivotably secured to the main frame  11  below the operator&#39;s platform  14 . The housing  50  comprises an upper wall  52  and a lower wall  53 , interconnected by a pair of side walls  54 . The rear end of the housing  50  is provided with a transverse drive shaft  56  which extends through the side walls  54  and is provided with a plurality of (e.g. four) sprockets  57 . At the front end of the elevator assembly  23 , a drum  59  is installed for rotation between the side walls  54 . The drum has a front shaft  60  extending through apertures in the side walls and received in bearings  61  which are mounted to pivot arms  63 . At their rear ends these arms  63  are pivotably affixed to the outside of the side walls  54  at pivots  64 . 
   The elevator assembly  23  includes elevator mechanism comprising a plurality of endless, flexible members, e.g. chains  66 , which are trained along parallel paths over the sprockets  57  and the front drum  59 . The chains are driven by the sprockets  57  on the drive shaft  56 . Mounted across and to the chains is a plurality of generally transverse slats  68  which will be described in further detail hereinafter. 
   The lower wall  53  of the housing  50  may be provided with a wear plate along which the lower run  66   a  of the elevator mechanism conveys the harvested crop to the inlet of the threshing and separating assembly  16 . During operation of the elevator assembly  23 , the drive shaft  56  is rotated CCW as seen in  FIG. 2  to make the slats  68  adjacent the front drum  59  engage and grab the crop material which is delivered thereto by the header auger  25 . The slats of the lower run  66   a  convey the crop rearwardly and upwardly along the lower wall  53  or the wear plate, if present, to the outlet of housing  50 , where the crop is combed away from the elevator mechanism by the front portion of the threshing rotor  27 . 
   In order to prevent that stray material that was not removed immediately from the elevator mechanism, falls back from the upper run  66   b  onto the lower run  66   a  and starts wrapping around the drive shaft  56  or accumulating around the sprockets  57 , an intermediary shielding mechanism is provided between the lower and upper runs  66   a ,  66   b  of the elevator mechanism. In the present embodiment, the shielding mechanism consists of a stationary rear plate  70  and a removable front plate  71 . The rear plate  70  is welded between and to the side walls  54  and to a transverse tubular reinforcement  73  disposed near the drive sprockets  57 . The front plate  71  extends forwardly from the front edge of the rear plate  70  towards the front drum  59  and is attached by bolt mechanism  75  to the side walls  54  of the housing  50 . 
   As illustrated in  FIGS. 3 to 6  the elevator slats  68  are made out of a generally S-shaped profiles. They have a substantially flat middle portion  120  provided with holes for attaching the slats  68  to the chains  66 . The front portion  122  is substantially perpendicular to this middle portion and has a lower edge which is provided with notches  123 . During conveyor operation the front portion  122  engages the harvested crop material, while its lower edge moves adjacent to or slides over the lower housing wall  53 . The notches  123  may be applied to the profile by a continuous rolling operation. 
   The rear portion  124  extends from the middle portion  120  and has an upwardly curved cross section. The part adjacent the middle portion may be bent downwardly, but the outer edge faces upwardly. This rear portion provides additional strength to the whole slat  68 , such that the distance between the parallel chains  66  and the corresponding length of the slats  68  can be extended without making the slats prone to distortion during harvesting operations. 
   As the chains  66  follow a curved path around the sprockets  57 , the slats  68  attached thereto are equally rotated. In this area the rear portion  124  momentarily moves downwardly to the lower wall  53  and is forced into the conveyed crop. The edge of the rear portion  124  is directed away from the normal crop flow such that it does not damage the crop material. For instance, this arrangement prevents additional cuts in the kernels when corn ears are transported. 
   The slats  68  are made out of flat steel material to which the S-shaped profile is provided in a compound, continuous rolling operation. The S-shaped cross section has first and second surfaces  125  and  126 , respectively, interconnected by first and second edges  127  and  128 , respectively, along sides of the slat. This rolling operation may also include the addition of notches  123  to the front portion  122  alone the first edge  127 . The notches  123  extend inwardly from the first edge  127  of the slat into the first and second surfaces  125  and  126 . 
   Although the present invention has been described with reference to a particular machine and structure, other embodiments can be thought of without departing however from the scope of the invention as defined in the claims. For instance it is conceivable to provide the rear portion  124  with a forwardly curved profile.