Abstract: Transducer structure for a steerable axle includes a transducer assembly having a housing and a cup-shaped journal, having an apertured bottom portion, fixed to the spindle of a steerable wheel by the spindle bolt for rotation with the spindle about the spindle axis. A bracket connected to the guide axle knee nonrotatably supports housing structure above the spindle, and the journal is rotatably received within a bearing and seal in the housing structure. The journal includes apertures which receive mating pins which constrain the rotary member for rotation with the journal relative to the housing structure. A special fixture supported by the tie-rod bolt accurately centers the journal during assembly and facilitates calibration of the transducer.

Abstract: A row marker featuring tandem cutting discs, each with convex and concave surfaces, which are disposed to present the convex surfaces to opposite sides of a cutting line. The disc's cutting edges are rotatably adjustable, either individually or as a pair, whereby they can be rotated to widen or narrow the furrow if desired. The cutting edges are set to cut along the same line or overlap slightly at their deepest points. The trailing disc cuts the earth to a deeper point than the lead disc. The depth of the marker furrow can be varied by adjusting a forwardly disposed ground wheel. An extension arm connects the tandem cutting discs to a planter at a selected distance to provide the precise location of the marker furrow. An adjustable joint allows realignment of the cutting edges to insure contact with the soil in a true vertical position when extension arm length is altered.