Seed planting device

Claim 1

In a seed planting device of the type having a pick-up head including seed pick-up apertures for picking up individual seeds from a bulk supply at one location and transferring such seeds to a second location for dispersal in a spaced array, improved air transfer apparatus for selectively providing a positive, negative or neutral pressure condition at said apertures, said apparatus comprising: (a) a vacuum source having a suction port and an exhaust port; (b) first tubular transfer means for connecting said suction port to the pick-up head; (c) second tubular transfer means for connecting said exhaust port to the pick-up head; and (d) valve means having a hollow body portion and connecting said first tubular transfer means to said pick-up head, said valve means including closure means movable within said hollow body portion from a first lower position enabling suction from said first tubular transfer means to be applied to the pick-up head to a second higher and vertically opposite position enabling such suction to be cut off from the pick-up head, means normally biasing said valve closure means to said first position, said valve means body portion having the discharge end of said second tubular transfer means terminating therein and controlled by said closure means, said discharge end being sealed off by said closure means when said valve is in said first position and being opened when said valve closure means is raised to said second position, manual closure operator means connected internally of said body portion to said valve closure means and having an operator portion slidably mounted in said body portion for vertical movement and engagable externally thereof against said biasing means to position said closure means, and manually operable exhaust control means on said second tubular transfer means for selectively connecting or disconnecting said vacuum source exhaust port to supply a flow of exhaust air at said discharge end, whereby with said vacuum source energized, said valve means when said closure means is placed in said first position provides a negative pressure condition at said apertures, when said closure means is moved to said second position provides a neutral pressure condition at said apertures and when said closure means is moved to said second position said manual exhaust control means enables said exhaust port to be operatively connected to said second tubular transfer means discharge end to provide a positive pressure condition at said apertures.