Harvesters – Cotton – Pneumatic
Reexamination Certificate
2000-03-22
2001-11-27
Pezzuto, Robert E. (Department: 3671)
Harvesters
Cotton
Pneumatic
Reexamination Certificate
active
06321516
ABSTRACT:
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates generally to crop conveying ducts for harvesters, and, more specifically, to a conveying duct for a cotton harvester.
2) Related Art
Cotton harvesters such as the John Deere Model 7455 Cotton Stripper include a large central duct for conveying cotton upwardly and rearwardly from the stripping units toward a cleaning grate adjacent a cotton cleaner and a basket on the harvester. Several problems exist with the previously available ducts. The ducts, which are fabricated from relatively heavy sheet metal and require welding, are expensive to manufacture. Large flat surfaces on the duct are very prone to flexing or “oil canning” motion caused by turbulent air flow within the duct. The motion results in fatigue, particularly at joints which are spot-welded, and decreases duct reliability. To reduce such motion, additional structure is provided on a portion of the duct, increasing cost and weight.
The trajectory of the cotton is influenced by the duct configuration, and present duct configurations fail to provide good air flow and evenly distributed cotton flow across the width of the duct, thereby decreasing conveying, separation grate and cleaner efficiency. The cotton tends to concentrate in the central portion of the duct so that the effective cleaning area of the separation grates is reduced. The central concentration also results in bunching of material on the grate assembly eventually leading to plugging, usually when there is low air speed on one side of the assembly. On some grate assemblies, plates are provided at the sides of the grates in the areas where there are relative dead spaces. To distribute the centrally concentrated material across the width of the cleaner, vanes are added to the cleaner inlet area.
BRIEF SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved conveying duct for a harvester. It is a further object to provide such an improved duct which eliminates most or all of the aforementioned problems.
It is a further object of the present invention to provide an improved conveying duct for a cotton harvester which is stronger yet lighter and less expensive to manufacture than at least most previously available ducts. It is a further object to provide such a duct which is more reliable than most previously available ducts.
It is still another object of the present invention to provide an improved duct for a cotton harvester which reduces or eliminates fatigue failures caused by flexing or oil-canning effects without need for separate stiffeners or the like which increase the cost and weight of the duct. It is another object to provide such a duct which obviates welds, reduces assembly time, and requires a minimum of additional hardware.
It is yet another object to provide such a cotton conveying duct with improved air and cotton distribution characteristics. It is a further object to provide such a duct which distributes the cotton more evenly across the duct width than most previously available ducts. It is still another object to provide such a duct which eliminates dead spaces so special side plates on the grate assembly are unnecessary and which distributes cotton more uniformly across the width of the duct to obviate vanes in the cleaner input duct. It is another object to provide such a duct which distributes cotton in the duct for better flow adjacent the separation grates so more trash is removed and plugging is minimized.
A cotton conveying duct constructed in accordance with the teachings of the present invention includes a generally continuously curved panel configuration providing both strength and excellent material distribution characteristics. The duct, as viewed from a side of the harvester, has a gentle S-shape which encourages the material to move towards the front side of the duct in the upward direction for a better upper duct flow pattern and more efficient separation grate action. Distribution across the width of the cleaner is also enhanced, and special vanes or the like for spreading the flow of material are eliminated. The cross sectional area of the duct is maintained generally constant as the depth decreases in the upward direction, with a slight increase in area from bottom to top.
The curved configuration provides stiffness and strength and eliminates the weight and cost of special stiffeners. Oil canning is eliminated. Use of a Pittsburgh lock joint construction eliminates welding and weld fatigue cracking and speeds assembly. The cost to manufacture the improved duct is only a fraction of that of conventional ducts, and duct weight is reduced. The increased strength of the new construction also permits use of thinner gauge stock material having a thickness substantially less than 0.060 inches (0.15 cm.), further reducing cost and weight.
These and other objects, features and advantages of the present invention will become apparent to one skilled in the art upon reading the following detailed description in view of the drawings.
REFERENCES:
patent: 4579375 (1986-04-01), Fischer et al.
patent: 4606177 (1986-08-01), Schlueter
patent: 5394679 (1995-03-01), Schlueter
patent: 5857908 (1999-01-01), Snyder et al.
patent: 6205756 (2001-03-01), Orsborn et al.
Goering Kevin Jacob
Wigdahl Jeffrey Scott
Deere & Company
Pezzuto Robert E.
LandOfFree
Cotton conveying duct does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cotton conveying duct, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cotton conveying duct will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2584139