Abstract:
These and other objects are attained by providing an improved harvester header side shield and latch mechanism consisting of a shield vertically pivotable upwardly and rearwardly about a horizontal hinge located on the upper rear portion of the header. The shield is lockable in the operational position and automatically engages a latch mechanism in the raised position that is manually released by the operator for lowering. Guides are provided on the inner side sheet of the header to assure that the shield moves into, and stays, in the proper location during operation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The invention is this application is related to that disclosed and claimed in U.S. applications Ser. Nos. 10/349,442 and 10/348,882, entitled “Vertically Pivoting Plastic Header Side Shield” and “Vertically Pivoting Plastic Header Side Shield and Latch Mechanism”. The first referenced application was filed on the same date as the instant application, in the names of Kenneth R. Underhill and Keith J. Corner, and the second was filed on Jan. 22, 2003, in the name of Kenneth R. Underhill. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to an agricultural crop harvester header, and more particularly to a unique side shield and latch mechanism for the outside ends of such headers. 
     In modern agriculture, especially in regard to harvesting forage crops, it is the current practice to cut a relatively wide swath of the crop within a range of anywhere between 10 and 16 or more feet in width, and then consolidate the crop into a narrower, substantially continuous windrow, in which form the crop is left to dry in the field until the moisture content has been reduced to a value suitable for subsequent harvesting operations, such as baling. 
     The most recent designs of windrower headers employ a consolidating auger operationally behind a cutterhead and rotating reel to receive the cut crop material and convey it centrally of the header from either lateral end portion thereof for feeding into a crop-conditioning mechanism, conditioning rolls, for instance. A header of this general type is shown and described in U.S. Pat. No. 3,324,639 issued to L. M. Halls et al. on Jun. 13, 1967 and U.S. Pat. No. 4,296,592 issued to Irwin D. McIlwain on Oct. 27, 1981. 
     Typically, the major components of all harvester crop headers, including side shields, have been formed from sheet metal. One aspect of the instant invention is that the shield be formed by a rotational molding process. 
     Rotational molding is a known process used for manufacturing plastic components by first creating a mold formed in the shape of the component to be formed, and then pouring a suitable quantity of powdered polyethylene resin into the mold, after which the mold is closed, heated to about 600° F. and slowly rotated for approximately ten minutes to evenly distribute the resin to the periphery of the mold. The heating process converts the powdered resin into an integral plastic sheeting having a generally uniform thickness conforming to the shape of the mold. The material thickness of the component part being formed is dependent on the amount of resin material first poured into the mold. By precise formation of the mold and careful calculation of the amount of resin to be applied, a generally hollow polymer component can be formed from this process. 
     The rotational molding process has not been traditionally used in constructing parts for agricultural equipment. Such component parts have typically been cast of metal or formed from sheet metal to provide the desired durability and function. Nevertheless, rotationally molded components are manufactured with significantly less cost than corresponding metallic parts and contain significantly less weight. Furthermore, the function of metallic components have heretofore not been duplicated, such as providing hinged closures and liquid-tight connections. 
     Traditional header side shields of the type under consideration herein are attached to the header or side sheet by generally vertical hinges. To open the shield for access to the shielded components, the shield is pivoted outwardly and rearwardly from the front. 
     Additionally, headers of this type are subject to considerable physical abuse. Not infrequently, the ends of the headers strike fence and gateposts, rocks, tree stumps, bales of hay, and the like. Often, encounters of this kind result in dents and breakage of the shield. 
     Plastics have been found to present particular problems in agricultural applications that relates to high ambient temperatures. One of the biggest single markets for windrower headers is in the Imperial Valley where ambient temperatures are known to rise as high as 160° F. Plastics, particularly large pieces of plastic tend to expand more than other materials, such as steel, raising fit and alignment problems. 
     Accordingly, it would be highly desirable to provide a unique structure for a rotationally molded side shield and latch mechanism for a harvester header side shield that overcome the above-identified problems. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a header side shield and latch mechanism that is stable, convenient and locks automatically and safely into the raised position. 
     It is a further object of the present invention to provide a header side shield that pivots upwardly and rearwardly to provide complete access to the operational components of the header for lubrication, inspection, adjustment, and repair, and latches “hands-free” into place until manually released by the operator. 
     It is a still further objected of the present invention to provide a header side shield that pivots upwardly and rearwardly about a horizontal hinge located away from most damaging obstacles and allows for access in tight quarters, such as a narrow shed or service bay, where a side opening shield could not be fully opened. 
     Another object of the present invention is to provide a header side shield and latch mechanism that minimizes the interference to the flow of uncut crop material rearwardly along the side of the header. 
     Another object of the present invention is to provide a header styled, streamlined and modern looking in appearance that is crop-friendly to minimize crop knock down and has no sharp edges or protrusions to run down or hairpin crop materials. 
     Another object of the present invention is to provide a header side shield and latch mechanism that provides a stabilizing support in side-wind conditions, reducing damaging loads on the shield hinge. 
     It is another object of the instant invention to provide a header side shield and latch mechanism that reduces the build-up of cut crop material and chaff between the shield and the component supporting structure (side sheet) of the header. 
     It is yet another object of this invention to provide an improved header side shield and latch mechanism that is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple and effective to set up, adjust and use. 
     It is yet another object of the present invention to provide an improved side shield that maximizes operator&#39;s sight line, provides no sharp edges or protrusions to run down or hairpin crop materials, and uses molded-in inserts to attach latches, light brackets and hinges. 
     It is a still further object of the present invention to provide a side shield for a harvester header that is formed from a rotational molding process. 
     It is a still further object of the present invention to provide a double-walled dent-resistant side shield for a harvester header that is rotomolded of UV stabilized polyethylene material. 
     These and other objects are attained by providing an improved harvester header side shield and latch mechanism consisting of a shield vertically pivotable upwardly and rearwardly about a horizontal hinge located on the upper rear portion of the header. The shield is lockable in the operational position and automatically engages a latch mechanism in the raised position that is manually released by the operator for lowering. Guides are provided on the inner side sheet of the header to assure that the shield moves into and stays in the proper location during operation. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: 
     FIG. 1 is a partial top plan view of an agricultural header including the shield and latch mechanism of the instant invention; 
     FIG. 2 is a side elevational view of the header of FIG. 1, taken along lines  2 — 2  showing the shield and latch mechanism of the instant invention and the drive subsystems of the header in phantom; 
     FIG. 3 is a side elevational view, similar to FIG. 2, showing the shield of the instant invention in the raised and locked position; 
     FIG. 4 is a cross-sectional view of the shield taken along lines  4 — 4  of FIG. 3; 
     FIG. 5 is a partial side view of the latch mechanism of the instant invention; 
     FIG. 6 is a partial cross-sectional view of the latch mechanism taken along lines  6 — 6  of FIG.  5 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following description, right hand and left hand references are determined by standing at the rear of the machine and facing in the direction of forward travel. Also, in the following description, it is to be understood that such terms as “forward,” “left,” “upwardly,” etc., are words of convenience and are not to be construed as limiting terms. 
     Referring now to the drawings, and particularly to FIG. 1, there is partially shown a crop-harvesting machine, such as a self-propelled windrower, generally indicated by numeral  10 , incorporating the principles of the present invention. While the machine  10  is of the self-propelled type, the improved structure incorporated therein may readily be incorporated into a pull-type machine, or a header attached to a traditional tractor. 
     The machine  10  is provided with a mobile frame, generally designated  12 , which is commonly referred to as a power unit or tractor and adapted to move forwardly across a field. An elongated header  14  is disposed forwardly of the tractor  12  and extends transversely to the forward direction for harvesting crop material from the field as the tractor  12  advances forwardly. 
     The tractor  12  includes a main frame with a pair of laterally spaced rear castor-type wheels (not shown) depending from the rear end thereof (not shown). Depending from the front end of the main frame is a pair of laterally spaced front wheels  16 . The tractor  12  further includes a power source (not shown) mounted adjacent the rear end thereof and suitable known drive components (not shown) for transmitting power to the front wheels  16  and the header  14 . For a more complete understanding of an exemplary arrangement of the power source and drive components, attention is directed to U.S. Pat. Nos. 3,699,754 and 3,777,833. A more detailed description of such features need not be presented herein for a complete understanding of the present invention. 
     The header  14  includes a pair of vertical side sheets  18 ,  20  and a curved floor  22  extending laterally therebetween. Centrally defined in a rear vertical portion of the floor  22  is a generally rectangular discharge opening (not shown). As will be subsequently described in greater detail, the header  14  is adapted for flotation on the field by a suspension system, generally designated by numeral  24 , which supports most of the weight of the header  14 . The remaining weight of the header  14  is supported on the field by a pair of ground engaging skid shoes  2  (not shown) fixed to the lower outside portions of the header  14 . 
     Further, the header  14  includes a transversely extending reel  30  being rotatably mounted at its opposite ends forwardly between the header side sheets  18 ,  20 . The reel  30  is provided with a series of tines  32  laterally spaced about the periphery thereof and, as the reel  30  is rotated in counterclockwise fashion, adapted to engage the oncoming standing crop and sweep it rearwardly over a cutterbar assembly  34  mounted at its opposite ends forwardly between the header side sheets  18 ,  20  and along the forward edge of the header floor  22  at a transversely-extending position spaced below the reel  30  and just above the ground. Disposed behind the reel  30  is a transversely-extending auger  36  also being mounted at its opposite ends to the header side sheets  18 ,  20  and adapted to receive the cut crop moved rearwardly up the floor  22  by the reel  30 , consolidate it and discharge it into the discharge opening defined in the rear vertical portion of the floor  22 . A well-known conditioning unit  38  is mounted beneath the forward end of the main frame and between the front wheels  16  will receive the crop material moved rearwardly through the header discharge opening, condition it and deposit it in a windrow back on the field. Such arrangement of the conditioning unit is disclosed in greater detail in U.S. Pat. No. 3,699,754. A more detailed description of such arrangement need not be presented herein for a complete understanding of the present invention. 
     As briefly mentioned hereinabove, the header  14  is adapted for flotation on the field by an exemplary suspension system  24  that pivotally mounts the header  14  from the tractor  12 . The suspension system  24  includes a pair of laterally spaced apart lift arms  40 ,  41 . The arms  40 ,  41  at their forward ends are pivotally connected to respective lower, laterally spaced portions of the header  14 . 
     The suspension system  24  further includes a stabilizing bar  42  being centrally located, extending between and pivotally interconnecting the forward end of the main frame and an upper central portion of the header  14 . 
     Referring now to FIGS. 1-3, it can be seen that the central shaft  50  of reel  30  is rotated from the left side of header  14  by reel drive sprocket  52 , fixed to shaft  50 . A reel sheave  54  is affixed to stub shaft  56  and to a smaller reel drive sprocket  58 . A drive chain  60  engages the teeth on sprockets  52  and  58  such that rotation of sheave  54  results in rotation of reel  30 . A tensioning sprocket  62  may be provided to maintain the appropriate chain tension. The relative operational diameters of the sprockets and sheaves are selected to provide the appropriate reel speed to ground speed ratios. 
     A v-belt  64  is fitted to the two sheaves  54  and  66  such that rotation of sheave  66  results in rotation of the reel  30 . As discussed above, an adjustable tensioning pulley  68  may be advantageously added to extend the operational life of the v-belt  64  and improve the operation of the drive system. 
     Auger  36  is provided with an axial shaft  70  about which the auger rotates. On the left outward end of shaft  70  there is located a drive sprocket  72 . Drive chain  74  engages the teeth on sprockets  72  and  76  such that rotation of sprocket  76  causes auger  30  to rotate in a relationship determined by the relative diameters of the two sprockets. A tensioning sprocket  78  can be added to take up unwanted slack in chain  74 . 
     During field operation a large quantity of cut crop material flows through the header, generating considerable chaff and other debris that has a tendency to find its way to the various drive components and accumulate thereon. This build-up of materials causes extra wear on these components and may, in some instances result in a breakdown. In FIGS. 1 and 3 it can be seen clearly that the side sheet  18 , on the left side of header  10 , is an additional structural element of the header  10  that provides support for the various drive components thereof as well as a barrier to cut crop material, chaff and other debris from contact with the drive components on the exterior of the side sheet  18 . The common well-known shielding for similar headers is made of sheet metal in the form of an open-sided box, hinged to the side sheet or other structural member by a generally vertical hinge along the rear of the header. The shield was non-conforming to the drive components and generally created a uniform enclosure for those components with the side sheet when in the operational position. 
     As can be seen in the figures, particularly FIGS. 3 and 4, the improved side shield  80  of the present invention is comprised of a single molded double-walled component of a durable plastic resin, such as polyethylene. In sectional view, see FIG. 4, the shield is shown more or less molded to accommodate the drive components, i.e., to vary in depth to match the drive components and reduce the amount of open space between the shield  80  and the side sheet  20 . This reduction in space reduces the build-up of cut crop material, chaff and debris, with the resultant improved performance and reduced maintenance. It should be noted from these figures also that the molding is not completely around the various operational components, but rather is such that there is adequate space provided to permit the shield to rotate upwardly into the open position without interference between the shield and these components. 
     To further inhibit the build-up of materials, shield  80  is, as seen in FIG. 4, open along the bottom thereof, i.e., the shield does not have a lip across the bottom portion thereof so that any materials that do enter the closed area of the shield may fall through the bottom onto the ground. 
     The double-walled configuration is made possible by rotational molding (also referred to as “rotomolding”) techniques, and advantageously produces a shield that is of sufficient rigidity so as not to require a frame structure, is rust-free, is lighter in weight than its sheet metal predecessor, requires fewer parts, need not be painted, and can withstand considerable physical abuse without breaking or becoming misshapen. The design and construction of shield  80  is such that it additionally reduces rattles and may conveniently have a textured outer surface to minimize scratch mark visibility. The double-walled configuration is fully enclosed to prevent dirt and moisture from entering the shield cavity that would make it heavy to raise to the open position. Another advantage of the molding process is that integral handhold depressions can be easily formed in the outer side of the shield, such as at  99  in FIGS. 2-4. In the instant application, it has been determined that the walls of the shield should be approximately {fraction (3/16)}ths of an inch thick. 
     Affixed to side sheet  20 , toward the front thereof is a shield support  86  (see FIG.  3 ). The shield support includes a lower angled portion  88  and an upper portion  90  formed with an angled outside lip  92  thereon. The forward portion  94  of shield  80  matches the shape of the support  86  and is additionally formed with a reduced thickness segment  96  that fits snugly in the upper portion  90  of support  86 . When moved into the lowered operational position, the front portion  94  of shield  80  is guided into position relative to the support  86  by upper portion  90  of the support and also held in the appropriate lateral position thereby. Support  86  is dimensioned such that it will function properly even when shield  80  has expanded due to high ambient temperatures. An elastic rubber hold-down  98  is affixed to the front of support  86  to manually engage pin  100  on the upper front of shield  80  and further hold the shield in the operational position. This easy access front hold-down keeps the shield  80  will not move toward, or swing outwardly, an open position—the majority of the weight biases the shield into the closed position. Additionally, support  86  may be flared slightly outwardly to promote the guidance characteristic when the shield is expanded due to high temperatures. 
     The figures further show a multi-purpose latch bracket  110  (only one of which will be described) on either side of the rear of header  14 . The bracket  110  (FIGS. 5 and 6) is comprised of a u-shaped primary support member  112  affixed to a structural component at the rear of header  14 , as by bolts  114 , for example. Affixed to the legs of the u-shaped primary support member  112 , by bolts  115 , for example, is a pair of bracket arms  116 ,  118  that extend upwardly therefrom. Bracket arms  116 ,  118  are formed into a rigid latch structure by the addition of cross member  120  at the top and a leg  122  formed near the bottom in support member  112 . The cross member  120  and leg  122  may be conveniently welded to the bracket arms  116 ,  118  for a rigid latch structure firmly affixed to header  14 . 
     The actual latching mechanism  124  is within the latch structure between cross member  120  and leg  122 . The latching mechanism comprises a latch  126  in the form of a small plate freely pivotable about bolt  128  and a second cross member  130 . Cross member  130  has a generally square aperture therethrough  132  through which a portion of latch  126  extends such that latch  126  is limited by the sides of aperture  132  in the amount of free rotation. The latch geometry somewhat utilizes the mechanics of a ratchet when allowing the latch hole  156  to pass the latch  126  when raising the shield, but entraps the latch within the latch hole  156  when trying to lower shield  80 . Latch  126  is allowed to pivot away from the latch hole  156  when raising shield  80 , but does not have a full range of pivot in the opposite direction when lowering, preventing the shield from dropping unless and until latch  126  is manually tripped. 
     A hinge  140  is affixed to the top rear portion of shield  80  by, for example, bolts  142 . Hinge pin  144 , in the form of a bolt, is fixed to the primary support member  112  by a pair of ears  146 ,  148 . Hinge plate  150  includes, at one end, a barrel  152  that wraps around pin  144  for rotation, and a latch arm  154  at the other. Latch arm  154  has a latching hole therethrough  156  that is slightly larger than the width of latch  126 . In operation, as can be seen in FIG. 5, by raising shield  80  it is pivoted about hinge  140 , bringing the upper end  158  of latch arm  154  into contact with latch  126 , causing it to pivot rearwardly. As the shield is raised further, latch  126  falls into latch hole  156 . By releasing the shield at this point, it is locked into place by the interference created between latch  126  and the rear wall of aperture  132 . To release the shield  80 , the shield must be raised a small distance so that the operator may manually push latch  126  into the dotted line position shown in FIG. 5, eliminating the interference and allowing the shield to be pivoted forwardly into the operational position. This arrangement provides for automatic latching in the raised position, requiring manual intervention to release and replace the shield into the operational position. Further, shield  80  is easily removed from the header by the removal of a single hinge bolt  144 . 
     A important issue that is raised by an upwardly pivoting shield relates to winds moving across the field. In the raised position, the shield  80  provides a significant surface area that, when hit by a side-wind, would produce considerable bending forces on the hinge  140 —forces that could break or damage the hinge or shield. Hinge  140  is intended to be quite strong; however, the design of the latching mechanism is such that it provides additional structural strength to maintain operational integrity even in relatively high side-wind conditions. Latch arm  154  fits, in the raised position, between bracket arms  116 ,  118  of bracket  110 , generally adding the structural strength of bracket  110  to that of the hinge to counter the forces on the shield due to the side-winds (see FIGS.  3  and  5 ). 
     Conveniently, a warning light  160  may be affixed to the latch structure to enhance the safe field and road operation of the equipment. 
     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 inventions. 
     Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.