DEVELOPMENT OF A SEEDLING PICK–UP DEVICE FOR VEGETABLE TRANSPLANTERS

A new seedling pick–up device for vegetable transplanters was developed and evaluated in a laboratory. The pick–up device extracts seedlings from a 200–cell tray and transfers them to a position from which they can be transplanted into the soil. The device consists of a path generator, pick–up pins, and a pin driver. The path generator is a five–bar mechanism comprised of a fixed slot, a driving link, a driven link, a connecting link, and a slider. The slider is constrained to move along the driven link and a fixed slot of combined straight–line and circular paths. The connecting link joins the driving link and the slider. When the slider moves along the straight–line path of the slot, it takes a seedling from a cell. When it moves along the circular path, it transfers the seedling to the transplanting hopper. The slider is an assemblage of pick–up pins and a pin driver, which are integral parts of the device. Operational parameters such as seedling age, approach direction of the pins, penetration depth of the pins into the cell, seedling holding method, and extracting velocity were examined using a prototype. The device extracted 30 seedlings per minute with a success ratio of 97% using 23–day–old seedlings.