Patent Application
20110209452
The present invention relates generally to cotton harvesters and, more specifically, to a low cost cotton picker having row unit drive synchronized with vehicle ground speed.
A large percentage of cotton growing areas in the world rely on low-cost manual labor or custom harvesters to harvest crop. Most commercially available cotton harvesters are too expensive to effectively compete in these cotton growing areas.
A large portion of the cotton that is grown in the world today is still hand picked. Although there is a desire in many areas to mechanize picking, most current four row and six row pickers are too expensive for many of these markets. Lower cost two row harvesters are available, such as the John Deere 7260 Cotton Picker and the Pamak Ptm2 tractor mounted picking machine, but the transition away from hand picking and custom harvesting is still hindered by cost.
At the time cotton harvesting was being mechanized in North America and Australia, the two row self propelled picker was the premium product, and one row tractor mounted pickers were the low cost solution. While the one row tractor mounted picker worked and was relatively low in cost, productivity was also low. Other disadvantages were the time and effort required for mounting and dismounting, the complexity of design necessary to provide mounting structure to accommodate a wide variety of tractors, and the lack of synchronization of row unit speed directly to ground speed for efficient operation of the picker spindles as they engaged the cotton plants. As a result, production of the tractor mount pickers lasted only a short time. Two row self propelled pickers became predominant. Later, the two row self propelled machines were replaced by the presently available four, five and six row machines. The need exists for an improved lower cost, efficient harvester that overcomes the mounting and speed synchronizing problems encountered with many of the previous low cost designs.
A low cost cotton harvester particularly desirable for emerging markets includes the incorporation of a tractor chassis with many components removed which are not necessary for operation of a cotton harvester. The tractor chassis is operated in the reverse direction, compared to the normal operation of a tractor, somewhat similar in fashion to the tractor mounted pickers that were prevalent around 1950 in North America. A row unit is located forwardly of the drive wheels, and an operator station is situated above the drive wheels to provide good visibility. A basket is mounted above the engine and the steerable wheels. Unlike the previous tractor mounted pickers, however, the chassis is substantially dedicated to cotton harvesting. In addition, the transmission on the chassis includes a mechanical front wheel drive (MFWD) output located between the drive wheels and the steerable rear wheels. In a conventional tractor chassis, the MFWD output would be drivingly connected to the steerable wheels. For the cotton harvester, the MFWD output is instead connected to the row unit drive. Since MFWD drive output is already synchronized with the tractor drive wheel speed, row unit drive is conveniently synchronized to ground speed using well established tractor drive technology and available components. When the tractor chassis stops, starts or changes speed, the row unit speed will change accordingly. By maintaining picking unit speed in synchronization with harvester ground speed, picking efficiency is increased and plant damage is decreased.
The harvester fan which provides air flow for propelling cotton between the row unit and the basket is driven by the existing power take off (PTO) shaft on the tractor chassis independently of the row unit drive. Therefore the fan can be run without need to drive the row units at the same time.
By providing a dedicated chassis, only a single set of controls is necessary so that duplication of operator station controls typically present in the afore-mentioned one row tractor mounted harvesters is avoided. The transmission gearing and tire size can be established to propel the machine at full speed in the harvester forward direction (the tractor reverse direction). Tire size may be specified to provide adequate ground clearance and to insure row unit synchronization to ground speed. The above-described configuration also advantageously places most of the harvester weight on the drive tires and aids mobility in adverse field conditions. The layout provides improved visibility and maneuverability to help the operator keep the harvester on the row. The leading row unit allows the operator to look forwardly and steer the unit directly on the row, and it assures less cotton is run over when a new field is opened.
Drop wheel axle structure for the drive wheels may be used to provide crop clearance and to facilitate use of the chassis as a sprayer when the row unit is removed. A sprayer pump is driven by the PTO shaft when the chassis is converted for spraying. A fully equipped tractor chassis rather than a stripped down tractor chassis may be used if the operator desires to convert the machine to normal tractor operation after the harvest season.
These and other objects, features and advantages of the present invention will become apparent from a reading of the description which follows when taken with the drawings.
Referring now to
For the configuration shown, the chassis 12 is operated in a reverse mode with the drive wheels 20 in the leading position and the steerable wheels 18 trailing the drive wheels 20. The conventional tractor operator station above the axles 20a and between the drive wheels 20 is replaced with an elevated operator station 36 offset in the forward direction F from the axles 20a generally above hitch structure 38. Alternatively, if the chassis is to be converted for normal tractor operation part of the year, the conventional tractor operator station may still be provided at location 36a and the elevated station 36 may be removed.
A row unit mounting frame 40 is connected to the forward end hitch structure 38. The hitch structure 38 as shown is a conventional three-point tractor hitch and is movable vertically to raise and lower the frame 40. A harvester row unit 46 is connected to the mounting frame 40 and is movable vertically with the frame 40 between the field-working positions (shown) and a raised transport position with activation of the hitch structure 38. The row unit 46 is shown as a conventional cotton harvester row unit of the type shown and described in U.S. Pat. No. 5,519,988 issued May 28, 1996 and assigned to Deere & Company. The unit 46 includes spindle drums 48 rotated by a row unit drive 50 connected to a telescoping drive shaft 52 powered from the engine 22. The spindles of the drums 48 are rotated in contact with the cotton plants in a row of crop 14 to remove cotton form the plants, and doffer structure (not shown) doffs the cotton from the spindles and directs the cotton into row unit door structure 56 in a well-known manner. An air duct 58 conveys the removed crop from the door structure 56 to a basket 60 supported over the engine 22. Air from a fan 62 is blown upwardly through a nozzle 63 into the central portion of the duct 58 in a conventional manner to induce airflow up from the door structure 56 and then propel cotton upwardly and rearwardly into the basket 60.
To synchronize the row unit drive speed with the ground speed of the chassis 12, the drive shaft 52 is driven from the MFWD output 30. A pulley 64 on the output 30 is connected by a belt 66 connected to a second pulley 68 on the aft end of a connecting drive 70 supported above one of the axles 20a. The drive 70 extends forwardly over the axle 18a to a universal connection 74 which, in turn, is connected to the aft end of the drive shaft 52. Since the speed of the MFWD output 30 is tied directly to the speed of the chassis 12, any increase or decrease in speed will result in a corresponding increase or decrease in the drive speed of the rotating drums 48 to maintain synchronization of spindle velocity with the cotton plants passing through the row unit 46.
To provide drive of the fan 62 independently of operation of the row unit drive 50, the fan 62 may be powered from the PTO 32. As shown, a pulley 76 is connected to the PTO 32, and a belt 78 (
If desired, the chassis 12 may be converted to normal tractor operation by providing a conventional operator station at the location 36a and removing the row unit 46, basket 60 and any other hardware required for the harvester operation but not needed for tractor operation. A drive from the MFWD output 30 to drive assist structure on the steerable wheels 18 may also be reattached if necessary.
As shown in
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. For example, although a cotton harvester row unit driven by the MFWD output 30 is shown, other implements requiring ground speed synchronization could also be mounted on the chassis 12 and driven by the MFWD output 30 and other crop inputs could also be conveyed using an independent PTO drive.
