Nut Sweeper

Overview

A nut sweeper gathers nuts that have fallen to the orchard floor into a single tidy row, a windrow, so a pickup machine can collect them in one clean pass. Tree nuts like almonds, walnuts, pecans, and pistachios are shaken from the trees onto the ground, where they lie scattered across the whole orchard floor mixed with leaves, twigs, and dust. Picking them up directly would be slow and would lift a lot of dirt. The sweeper instead brushes and blows the nuts off the open ground and out from under the trunks into a narrow centred row, leaving them clean and concentrated so the harvester that follows works efficiently and lifts little soil.

The machine combines the angled Sweeping Broom that does the brushing, an Air Blower that clears nuts the broom cannot reach, the Chassis and Engine that drives it, an alternative PTO Driveline for trailed models, the Windrow Shaper that forms the row, and the Operator Controls the operator works from.

The sweeping broom

The Sweeping Broom is the working heart of the machine. A Broom Core shaft carries a dozen Bristle Band rings of stiff polypropylene bristle, spun by a Broom Motor hydraulic motor. The whole broom is held at an angle by the Angle Frame so that as it rotates it flicks the nuts sideways and casts them steadily toward the row centre rather than straight back. Stiff but springy bristles move nuts along without crushing the shell or the kernel inside. A pair of Height Wheel gauge wheels on Ball Bearing mounts hold the broom just clear of the dirt, since a broom set too low scrubs soil into the windrow and one set too high leaves nuts behind.

The air blower

The broom cannot reach everywhere, so the Air Blower finishes the job. A high-volume Blower Fan in a scroll Fan Housing, driven by a Fan Motor on Ball Bearing mounts, sends air to a set of Air Nozzle nozzles aimed under the trunks and along the berm where the broom cannot sweep. The blast rolls nuts out from the tree base and along the raised soil berm into the broom's path. The blower matters most for the nuts that lodge against the trunk and in the irrigation berm, which are exactly the ones a broom alone leaves behind, and those add up to real losses over a large orchard.

Chassis and engine

Most sweepers are self-propelled. The Chassis and Engine is a narrow Main Frame sized to work between rows, with a Diesel Engine diesel driving a Hydraulic Pump that feeds the broom, fan, and the Wheel Motor motors on the four Drive Wheel turf wheels, fed from a Fuel Tank, all on Ball Bearing mounts and held with a Fastener Set. Hydrostatic travel gives the slow steady speed the work needs and lets one engine power every function. The machine creeps down each row, sweeping a full inter-row width per pass.

The trailed alternative

Some sweepers are pulled and powered by a tractor instead of carrying their own engine, and for those the PTO Driveline takes the place of the onboard hydraulic pack. A PTO Shaft takes power from the tractor power take-off into a Gearbox Housing whose Helical Gear Pair bevel set and two Drive Belt belts drive the broom and fan, sealed by two Oil Seal seals on Ball Bearing mounts. Trailed models cost less and suit growers who already own a suitable tractor, while self-propelled models are faster and more maneuverable in tight blocks.

Shaping the windrow

How clean the harvest is depends on the windrow, and the Windrow Shaper forms it. A trailing Finger Rake with springy Shaper Finger fingers combs the swept nuts inward to a single narrow row, and a Rubber Skirt rubber skirt on the Shaper Frame walls the row so the next pass does not scatter it. The fingers gather nuts without flicking dirt into the row, because every gram of soil in the windrow is grit the harvester and huller have to deal with later. A clean, narrow, well-walled windrow is what makes the pickup machine fast and the crop clean.

Controls and use

The Operator Controls run the machine from the seat. A Bare PCB controller and Microcontroller tie together a Drive Joystick that sets travel and a Valve Bank that meters oil to broom, fan, and wheels, wired through Connector and Wire Bundle links, with a Dust Sensor so the operator can trim fan speed to limit the dust cloud. Nut sweepers are the first step of mechanical nut harvest in almond, walnut, pecan, and pistachio orchards: after the trees are shaken, the sweeper windrows the crop, and a pickup harvester follows to lift it. The sweeper sets the pace and cleanliness of the whole harvest, since a fast clean windrow feeds a fast clean pickup, and one operator can sweep many acres a day.