MECHANICAL HARVESTER FOR PROCESS ORANGES

Abstract

An experimental, direct-drive, double-spiked-drum canopy shaker was developed to harvest oranges from highdensity groves. Each drum was 2.44 m (8 ft) in diameter and had six horizontal whorls spaced 300 mm (12 in.) apart on avertical shaft. Each whorl had 16 nylon rods, 32 mm (1.25 in.) in diameter, spaced at equal angles. Maximum rodpenetration into the canopy was 1 m (39 in.), shaking frequency was 4 to 5 Hz, and maximum horizontal displacement ofthe rod tip was of 250 mm (10 in.). The shaker was towed by a tractor along a tree row at travel speeds ranging from 1.4to 3.2 kph (0.9 to 2 mph). In the canopy space penetrated by the shaking rods, mature fruit removal averaged 71 to 91%.These promising results prompted the development of a prototype harvesting system. The shaker drums were enlarged to3.66 m (12 ft) in diameter and increased in height to harvest trees up to 4 m (13 ft) high. Fruit catching and conveyingcomponents were added under the shaker mechanism to collect and transport the detached oranges to the rear, row-centerof the shaker unit. A self-propelled bulk transport unit followed the harvest unit at a synchronized speed. The bulktransport unit had a conveying system that received the oranges from the harvester and transferred them to its rearhopper (6 t capacity). Both the harvester and the bulk transport unit had trash removal devices. Tests during the winterand spring of 1997 demonstrated potential of the system as an effective high-capacity harvesting alternative if compatibletree training and machine design parameters can be achieved. Fruit receiving grade at the processing plant was as goodas hand-harvested fruit.