Abstract: An adjustable down pressure mechanism is disclosed for use in association with a furrow forming apparatus of a seed planter. A parallel linkage arrangement is provided for mounting the apparatus on a tool bar of a tractor or the like, whereby the apparatus can follow the contour of the ground for efficient and consistent furrow formation. The down pressure mechanism comprises one or more springs operatively extending between upper and lower links of the parallel linkage. An upper support member for the springs is configured for convenient adjustable positioning along the upper links, whereby the pressure exerted by the springs on the furrow forming apparatus can be readily varied.

Abstract: A row unit with a mechanism which provides normal planting via a parallel bar linkage connection to the planter and which can be locked up in a raised, non-planting position when desired. The mechanism includes curved slotted openings in the lower bars of the linkage for frame mounted spacers as the frame pivots about the connection with the upper bars, and locking structure having detents to engage the spacers in the lowered working and raised non-working positions. The mechanism also prevents the release of the locking structure until the row unit weight is lifted therefrom.

Abstract: An air diffuses for use in a seed delivery tube of a pneumatic type of seed planter. This air diffuser is a short length of pipe which is perforated with a plurality of holes. The effective open area of the holes being approximately fifty-percent greater than the open area within the pipe taken on a cross-section of the pipe at the location of the holes. The air diffuser is spliced into the tube at a determinant length from the seed discharge end of the tube. It helps to maintain a uniform spacing of seed planted in the ground by preventing the buildup of back pressure upstream from the seed discharge end of the tube. If back pressure is permitted to build up in the tube, it will change the velocity of the seed traveling through the tube and effect the spacing of the seed planted in the ground.