Abstract:
A scrapping plate assembly for cotton harvesters includes a series of elongated trapezoidal ribs on the pressure plate defining separate paths for each picker spindle and providing an increased zone for compressively engaging the cotton bolls and extending the contact zone with the spindle barbs thereby increasing removal of bolls from the plant stalks and reducing dropage.

Description:
FIELD OF THE INVENTION 
     The present invention relates to cotton harvesters and, in particular, to a scrapping plate assembly for a cotton harvester row unit. 
     BACKGROUND OF THE INVENTION 
     Cotton harvesting has always been economically sensitive. When productivity increases were necessary to meet demand, manual picking was replaced by machinery. Though requiring less labor content, the machinery was capital intensive and less efficient in harvesting the available crop, failing to pick immature cotton bolls and dropping to the ground otherwise utile product. Gains were made in production speed and harvest efficiency as multi-row harvesters became available. Notwithstanding these improvements, to remain competitive in cost and supply, dual pass harvesting was employed to reap the cotton missed in the first harvest. 
     As the cotton sector evolves, smaller tracts of land are being supplanted by large fields, typically 1,000 acres or more. When all the costs and times associated with the larger fields have been considered, it is generally deemed uneconomical to conduct multiple pass harvesting, and the dropage and incomplete harvesting considered inescapable yield losses. Experience has shown that as much as 10% to 15% of the cotton lint remains on the stalks or on the ground after a single harvesting path. 
     Accessories such as scrapping plates have been employed for increasing efficiencies, but have not been considered acceptable for initial harvesting particularly for heavy cotton or use with short knotty cotton. These scrapping plates carried on the pressure plates are used in conjunction with spindle-type pickers, such as the John Deere 9965 series and as disclosed in U.S. Pat. Nos. 5,203,152 to Deutsch et al.; U.S. Pat. No. 5,519,988 to Copley; U.S. Pat. No. 5,557,910 to Del Rosario; U.S. Pat. No. 6,293,078 to Deutsch el al.; and U.S. Pat. No. Re. 32,699 to Fachini. Therein, vertical rows of rotating spindles carried on an orbiting drum engage the cotton bolls with pointed barbs, carry the entangled cotton between grid bars to doffer columns whereat the cotton is removed from the spindles and discharged to a vacuum conveyor system for delivery to the storage container. The scrapping plates have projecting triangular ribs that coact with alternate spindles to compressively force the cotton through the passage therebetween, engaging and capturing bolls that would otherwise not be harvested. The contact path is relatively short, about 3 inches, and shallow, about 1 inch, such that only about two barbs contact the compressed boll thereby limiting engagement with the result that cotton bolls may drop to the ground or be dislodged by the grid bars. 
     In view of the foregoing, it would be desirable to provide a cotton harvester adjunct for use in single pass cotton harvesting to provide increased yields through reduction in dropage and an increase in stalk picking. 
     SUMMARY OF THE INVENTION 
     The foregoing is accomplished in the present invention by a scrapping plate assembly that employs elongated tapered ribs adjacent each passing spindle to increase the contact path while the cotton in a compacted condition thereby increasing barb engagement and contact time with the spindle, increasing harvesting from the stalks and reducing dropage. The scrapping plate assembly includes a base plate, fixed at existing mounting holes on the rear of the row unit pressure plate, and carrying a plurality of elongated ribs providing independent parallel paths for each spindle. The ribs have a tapered entry section for progressively engaging the product, a center section for engaging multiple barbs with the product over a substantial distance and height, and a tapered exit section extending beyond the pressure plate and gradually reducing contact with the product adjacent the grid bars. The scrapping plate assembly markedly increases the cotton removed from the stalks in a single pass and decreases the product lost through dropage. 
     Accordingly, it is an object of the present invention to provide an accessory for increasing the cotton harvesting on a row unit cotton harvester. 
     Another object of the invention is to provide an improved scrapping plate yielding an improved cotton removal and retrieval in a single harvesting operation. 
     A further object of the invention is to provide a scrapping assembly for a cotton harvester row unit that increases the capture of cotton by the picker spindles. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The above and other objects and advantages of the present invention will become apparent upon reading the following written description taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a top view of a row unit for a cotton harvester provided with a scrapping plate assembly in accordance with a preferred embodiment of the invention; 
     FIG. 2 is a top view of the scrapping plate assembly; 
     FIG. 3 is a bottom view of the scrapping plate assembly; 
     FIG. 4 is a side view of the scrapping plate assembly of FIG. 1 mounted on a pressure plate of the row unit and indicating the spindle path in dashed lines; 
     FIG. 5 is a perspective view of the scrapping plate assembly and pressure plate; 
     FIG. 6 is a perspective view of a prior art scrapping plates mounted on a pressure plate; 
     FIG. 7 is a side elevational view of the scrapping plate assembly; and 
     FIG. 8 is a side view of the ribs of the scrapping plate assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings for the purpose of illustrating a preferred embodiment of the invention and not for limiting same, FIG. 1 shows a cotton harvester  10  having transversely spaced row units  12 , a single unit being representatively shown. Each row unit  12  is conventionally mounted on a support structure and a tractor for forward movement over a field to harvest parallel rows  16  of cotton plants. A suitable harvester for the present invention is the John Deere 9965 Cotton Picker. 
     Each row unit  12  includes a housing  20  having a row receiving area  22  between left and right stalk lifters  24 ,  26 . Front and rear picker drums  30 ,  32  are longitudinally disposed about vertical rotational axes  33 ,  34 . A plurality of spindles  36  are supported on the drums by picker bars  38  and mutually separated by horizontal grid bars  39 . 
     The picker drums  30 ,  32  include a cam arm and roller  40  supported in a cam track  42  for determining the spindle position during orbiting on the track. Doffer columns  50  are rotationally supported on vertical axes downstream of the respective picker drums for doffing cotton from the spindles  36 . Moistener columns  54  are supported at the front of the picker drums  30 ,  32  for wiping the spindles  36  after doffing of the cotton therefrom. 
     Adjustable vertically disposed pressure plates  60  are carried by the structure of the row unit opposite and slightly upstream of the picker drums. A scrapping plate assembly  62  is carried on the pressure plate  60  and is longitudinally traversed by the spindles  36 , as illustrated, during counterclockwise movement along the track  42 . During movement through the scrapping plate assembly  62 , additional cotton bolls, not securely initially gripped by the barbs of the spindles, are forced into extended affirmative contact, thereby increasing the amount of cotton engaged by the spindle barbs, passed between the grid bars  39 , and presented to the doffer columns  50  for removal. 
     The scrapping plate assembly  62  is illustrated in FIG. 5. A prior art scraping plate configuration is illustrated in FIG.  6 . Each version is mounted on a conventional pressure plate  60 . The pressure plate  60  includes a leading end  64  including a shaft  65  for conventional adjustable pivotal mounting on the row unit support structure, a curvilinear center section  66  having a curved crest  67 , and a rectangular slightly included planar end strip  68 . 
     Referring to the prior art arrangement of FIG. 6, a plurality of scrapping plates  70  are attached by fasteners  71  at vertically spaced locations along the trailing end of the pressure plate  60  at a plurality of spaced holes in the center section  66  and end strip  68 . The scrapping plates  70  are generally U-shaped having planar horizontally extending triangular ribs  72 ,  74  interconnected by a bent base  76 . The base  76  includes a front section  78  at the rear of the center section  66 , and a rear section  80  at the end strip  68 . In operation, a pair of spindles traverse each groove between the ribs. In other words, one spindle passes between the fasteners  71  and rib  72 , and another spindle passes between the fasteners  71  and the rib  74 . The next pair of spindles pass between adjacent ribs. All spindles rotate in a common direction. Accordingly, as a spindle traverses the path illustrated in the dashed lines in FIG. 4, the smaller cotton bolls will be wedged between the spindle and the adjacent rib during the transit time resulting in additional barbs penetrating the boll wall and entangling the fibers. If sufficient pick up is attained the cotton will remain on the spindle and pass between the grid bars  39  for removal at the doffer columns  50 , and resultant harvesting. Experience has revealed that secure retention is problematic and cotton drops to the ground, or dislodged at the grid bars. Moreover the second spindle of the pair does not benefit from the other rib interface inasmuch as the relative rotation tends to dislodge any gripping at the barbs against the trailing edge of the rib, generally resulting in dropage and/or non-harvesting. 
     The harvesting rate is increased and the dropage rate reduced by the scrapping plate assembly  62  of the present invention as shown in FIGS. 2 through 4. Therein, the scrapping plate assembly  62  comprises a base plate  90  carrying a plurality of uniformly spaced, transversely extending ribs  92  defining therebetween spindle paths for a single spindle. The ribs  92  comprise a first set corresponding in vertical location to the ribs  72 ,  74  of the above mentioned prior art construction of FIG. 5, and a second set interspaced therebetween and overlying the fasteners  71 . 
     Referring to FIG. 7, the base plate  90  includes a front section  96  terminating with a downwardly inclined lip  97 , and a rear section  98 . The front section  96  and rear section  98  are relatively inclined at a shallow angle of about 26° conforming to the transition angle between the center section  66  and rear strip  68  of the pressure plate  60 . The lip  97  overlies the crest  67  of the center section of the pressure plate  60 , having an include angle of about 135° with respect to the front section to provide a conforming fit thereat. The rear section  98  overlies the rear strip  68 . The sections  96 ,  98  include a series of square holes  102  aligned with the corresponding holes in the pressure plate  60 . It will be appreciated, accordingly, that the base plate  90  spans a substantially longer length than the prior art scrapping plate. 
     Referring to FIG. 8, the ribs  92  are a parallel array of generally inverted trapezoids thin plates welded to the base plate  90 . The ribs are formed of heavy gage plate, a thickness of about ⅛ to {fraction (3/16)} inch being preferred. Each rib  92  is vertically defined by an upper wall  100  and a bottom wall  106  parallel thereto. The rib has a height of about 1.5 inches. The upper wall  100  frontally terminates with a nose wall  102  inclined downwardly with respect thereto at a shallow angle of about 24°. The upper wall  100  rearwardly terminates with a reversely inclined exit wall  104  including a rounded tip  105 . The included angle between the upper wall  100  and the exit wall is about 30°. The exit wall  104  merges the bottom wall  106 . In assembly, the bottom wall  106  engages the rear strip  98  and extends substantially rearwardly therebeyond. A transition wall  108  extends upwardly from the front of the base wall  106  and intersects a downwardly inclined wall  110  frontally merging with the wall  102 . The walls  106  and  108  are welded to the walls  96 ,  98 . Downwardly opening semicircular slots  114  are formed in the ribs  92  registering with the holes  102  in the base plate  90 . In assembly, as shown in FIG. 4, the slots  114  allow the bolt  120  of the fasteners  71  to be inserted through the aligned openings and assembled with nut  122  to fixedly connect the scrapping plate assembly  62  to the pressure plate  60 . 
     Referring to FIG. 7, the ribs  92  present an entry section  130  of progressively increasing height, a center section  132  of relatively constant height, and a tail section  134  of progressively decreasing height. In operation, the cotton bolls will be preliminarily engaged by the spindle in the entry section  130 , increasingly entangled in the center section  132  and progressively released in the entangled state at the tail section  134  for passage between the grid bars  39 , thereby avoid any dropping or stripping at the grid bars and resulting in substantially improved yield. Further, all spindle traverse a similar scrapping path further increasing production. Tests to date have indicated that upwards of 6% to 10% more cotton lint are harvested with the present scrapping plate assembly in comparison to prior approaches, with or without scrapping plates. 
     Alternative to the accessory mounting of the ribs  92  is will be appreciated the benefits of the invention may be directly incorporated in the manufacture of the pressure plate or equivalent structure to thereby provide independent bounded paths for the spindles to compressively engage the cotton product passing therethrough. 
     Having thus described a presently preferred embodiment of the present invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the sprit and scope of the present invention. The disclosures and description herein are intended to be illustrative and are not in any sense limiting of the invention, which is defined solely in accordance with the following claims.