Abstract: An instrument and method for variable depth tillage is provided. A soil engaging implement has a pair of load cells and at least one strain gauge set mounted thereon. The load cells are used to determine a linear trend of topsoil resistance pressure change with depth as the soil engaging implement is drawn through the soil. The strain gauges are used to measure torque on the soil engaging implement caused by the load transmitted through the at least two load cells as well as the load applied to the point of the soil engaging implement. The linear trend of topsoil resistance pressure change with depth and the torque on the soil engaging implement are then used to determine both measured and predicted mechanical soil resistance to penetration applied to the point and the difference between the two values serves as an input for tillage depth adjustment.

Abstract: A PTO transmission includes a split power transmission unit having an output member connected to a PTO shaft, a first input connected to an engine output shaft and a second input connected the output of a variable speed drive unit. A control unit controls the speed of the variable speed drive unit as a function of sensed engine speed and maintains the PTO shaft at a constant speed. The split power transmission is preferably a planetary gear unit. The variable speed drive unit preferably includes a variable displacement hydrostatic pump driving a fixed displacement hydrostatic motor which drives a sun gear of the planetary gear unit. This system transmits power to the PTO shaft from both the engine and from the variable speed drive unit. The control unit may also control the variable speed drive unit so that the speed of the PTO shaft is maintained at a desired ratio with respect to the ground speed, or so that the speed of the PTO shaft is maintained at a speed set by an operator.

Abstract: A PTO transmission includes a split power transmission unit having an output member connected to a PTO shaft, a first input connected to an engine output shaft and a second input connected the output of a variable speed drive unit. A control unit controls the speed of the variable speed drive unit as a function of sensed engine speed and maintains the PTO shaft at a constant speed. The split power transmission is preferably a planetary gear unit. The variable speed drive unit preferably includes a variable displacement hydrostatic pump driving a fixed displacement hydrostatic motor which drives a sun gear of the planetary gear unit. This system transmits power to the PTO shaft from both the engine and from the variable speed drive unit. The control unit may also control the variable speed drive unit so that the speed of the PTO shaft is maintained at a desired ratio with respect to the ground speed, or so that the speed of the PTO shaft is maintained at a speed set by an operator.