Abstract: A marker assembly for use with an agricultural implement includes a marker wheel that may caster as needed to reduce loading of the marker assembly during deployment of the marker assembly, in response to variations in surface contour, and in response to changes in travel direction of the agricultural implement.

Abstract: An agricultural marker assembly is disclosed for use with a marker arm that extends from an agricultural vehicle wherein the vehicle moves along a primary travel direction during operation. The assembly includes an extension assembly including at least first and second members, each of the first and second members having first and second ends, the first member supported by the arm and extending generally in the direction opposite the primary travel direction, the second member supported by a first portion of the first member and extending at least in part away from the first portion of the first member along a trajectory lateral to the primary travel direction when the vehicle is moving in the primary travel direction. The assembly also includes a marker supported by the second member and separated from the first portion of the first member.

Abstract: A process for treating earth materials such as rock heaps to prevent acid rock drainage therefrom is disclosed. First, the oxygen concentration in the gas-phase of the rock heap is decreased, that is, displaced and/or depleted. This first step may be accomplished physically, chemically or biologically. Then, the gas-phase oxygen concentration in the heap is maintained at a low level. This second step may be provided for in a self-sustaining manner, like, for example, by covering the rock heap with soil and vegetation so that acid rock drainage is prevented indefinitely. Alternatively, the density of the gas-phase of the rock heap may be increased, and maintained at an elevated level indefinitely. The process is applicable to waste heaps from mining and industrial operations such as power generation and minerals processing, and to rubble collections in open and closed mines.

Abstract: Disclosed is a method for controlling the above-ground "raise height" of a seed-planting row unit on an agricultural planter having a row marker, a marker switch and a positioning assembly such as a solenoid valve and hydraulic cylinder for raising and lowering the row unit. The method includes enabling the positioning assembly to raise the row unit and changing the marker switch from its first to its second position when the row unit reaches a predetermined height. The positioning assembly is thereby disabled. Such assembly is re-enabled after a brief time delay. The method is carried out using a unique implement control circuit connected to the marker switch and the positioning assembly.

Abstract: A tri-fold row marker comprises three arm segments, a winglet pivotally coupled to the toolbar, an inner arm pivotally coupled to the winglet, and an outer arm pivotally coupled to the inner arm. A marker disc is mounted to the distal end of the outer arm for marking the ground surface when said row marker is its extended working position. The winglet is provided with a first bell crank extending upwardly from the winglet and a second bell crank extending downwardly from the winglet. The inner arm is provided with a third bell crank extending downwardly therefrom. A double acting hydraulic cylinder is pivotally coupled to the agricultural implement and the first bell crank for retracting and extending the row marker. An inner control arm is pivotally coupled to the agricultural implement and the third bell crank for pivoting the inner arm relative to the winglet when the hydraulic cylinder is extended or retracted. An outer control arm is pivotally coupled to the second bell crank.

Abstract: A sequencing valve utilized with a tractor-propelled planter having two row arms which pivot downward to the ground in an alternating sequence as the planter changes directions in the field. The sequencing valve is connected with the conventional hydraulic system which raises and lowers the planter at the end of each row so as to automatically lower alternate marker arms. This is achieved by pressurizing opposite ends of the sequencing valve spool for longitudinal movement through a cam means, causing the spool to rotate during movement in one direction whereby alternating lowering of the planter arms is achieved each time the planter is hydraulically lowered to the ground.