Geiger-Lund Model MH2026 2-row Selective Asparagus Harvester

Specifications:

Length:   9 feet
Width:   10 feet
Height:    5 feet
Weight: 2,700 pounds
Mounting: 3-point hitch. Class 3
Hydraulics: Requires 4 circuits. Max 1,500psi. Total flow from all four circuits less than 20 gallons per minute
Electrical: Requires 12 volts DC, max current draw 30 amps.
Estimated recovery (yield):  75%-85% of what a hand crew would get.
Estimated maximum harvesting speed: 3.5 mph.  (With 48-inch row centers that would be about 2.34 acres per hour, or 56 acres in 24 hours.)

Detailed Description

Mounted on the toolbar are two headers and an air compressor.  The compressor is driven by a hydraulic motor. Maximum flow for the motor is about 8 gallons per minute. The compressor runs continuously. The compressor has a receiver tank that has a bleed-off valve which opens if the pressure rises above 145psi.  The output from the receiver is fed to the regulated air tanks, one on each header.

The two headers are mounted to the toolbar in a similar fashion to a forklift. The headers are capable of 8 inches of vertical travel. Each header has a bed-height sensor and a hydraulic cylinder to keep the header at a pre-determined height above the bed.

The spear sensor is an assembly with vertical sheet metal vanes spaced three inches apart across the bed. The two outer vanes have two photo-electric beams spaced two inches apart. When a spear passes through those two beams it tells the machine how fast it is going. Each of the inner vanes has a photo-electric beam receiver and transmitter. If a spear is tall enough to break the beam this will tell the machine which channel it is in, thus which cylinder must be fired.  Knowing the speed of the machine, and the distance from the spear sensor, the machine calculates and implements the proper time to delay the cut.  Quite simple.

After passing through the spear sensor, the spears encounter the bottom pick-up unit.  There are ten counter rotating shafts covered with soft rubber fingers and inclined to the ground at about 30 degrees.  The finger rollers gently pull the spears into the proper set of rollers and while they are being pulled upward the blade cuts the spears slightly above the ground.  The spear is lifted up through the remaining pickup units and lands on the cross conveyor.  The baffle plates above the conveyor cause the spears to land butt-first onto the conveyor which pulls them towards the lug box butt-first.  As the conveyor fills the lug box it gets pulled forward in small increments. The filling process is controlled by a fixed-field optical sensor.

Above the toolbar each header has an electrical enclosure which houses the circuit board and controls for adjusting the cylinder stroke length and fine tuning the cut-timing.

There is a hydraulic flow control on each side of each electrical enclosure for setting the conveyor and pickup roller speed.

Each header has an air tank which is tightly regulated to plus or minus 1psi.  Tight air regulation is required for a consistent repeatable stroke length from the cutting air cylinders.

At the front of the machine, on the outside edge of each header, is a conveyor system that has a vertical rack holding 4 empty lug boxes. With four in the rack, and two on the conveyor prior to starting the machine will hold six empty lugs on each header.  After two lug boxes are full with another filling, a full lug must either be dropped into the furrow, or off-loaded at the end of the row.

Mounting the machine on a three point hitch instead of a tractor pull unit has several advantages.

• Works better in muddy conditions.
• It takes less room and less time to turn around at the ends of the field.
• Less ground compaction.