Improving the design of the trolley for the manual harvesting of strawberry

The main goal of the research is to identify the degree of influence of the asymmetry of the resistance forces on the rolling wheels of a trolley designed to relocate the picker in the strawberry garden plantation when hand picking berries on the stability of its straight-line movement. The theoretical hypothesis was formulated in relation to a three-wheeled cart, the front wheel of which is controllable and located in the central aisle, and the rear wheels - in two adjacent wheels. According to the results of calculations, with such an arrangement of the cart, ensuring the straightness of its movement only by varying the position of the reference point for the collector's leg when it is pushed away from the aisle surface is already difficult with a twofold increase in the resistance to rolling for one of the wheels. As a result of an experimental three-wheeled trolley test, it was found that when using wheels from a 700-mm diameter bike and its additional loading with ballast weighing 704,6 N, simulating the average weight of the picker, the triple difference between the wheel rolling forces occurs when an additional obstacle appears in front of one of they are only 13 mm high. When raising the height of an additional obstacle to 45 mm, the degree of differentiation between the forces of resistance to rolling wheels increased to 8,3 times. In this regard, it is advisable to supply the trolley with a device for additional manual adjustment of the process of its straight-line movement along the rows. In the experimental version of the trolley for this purpose, a lever was mounted on the axis of rotation of the front wheel fork, the free end of which was brought into a zone convenient for access by the assembler’s left hand.

berries, strawberries, a trolley for manual harvesting, resistance to rolling, straightness of movement