Abstract: A method for in-situ measuring the corrosion rate of a corroding site on an underground metal structure buried in soil, the structure being under cathodic protection. The structure-to-soil potential at varying depths above the pipeline is measured to a depth above, but not reaching the structure. These measurements are extrapolated to obtain data representing the structure-to-soil potential at the surface of the structure under the probe. The gradient of the electrical potential at this surface is used to calculate the corrosion rate of the defect. A special probe may be used to obtain the potential measurement data.

Abstract: A method of soil preparation simultaneously ploughs soil and tills soil ploughed in a previous pass. An apparatus for tilling soil provides tilling members mounted for deployment on either side of a tractor. The tilling members on one side of the tractor may be brought into engagement with the soil while tilling members on the other side of the tractor are lifted away from the soil. The tilling members are located to coincide with an adjacent strip of land ploughed in a previous pass of the tractor.

Abstract: On a tractor having a main frame channel that includes an overhead wall and depending side walls and a lift arm mounted on a rockshaft for raising and lowering a tractor-supported implement, a power means for rocking the rockshaft with a lost motion connection between the power means and the rockshaft, a vertical member extending through the overhead wall and freely swivable therein and having a manual controllable portion above the transverse wall structure and an axially hollow section beneath the wall structure, a fixed pipe-like member in axial alignment with the swivel member and having an internal threaded portion, a stud threaded into the pipe-like member and having a head seated in and connected to the hollow section of the swivel member to swivel therewith, and a vertically disposed rod having an upper end portion extending to and engaging the lower end of the stud and a lower end connected to the rockshaft in radial offset relation to its axis.

Abstract: An apparatus for a tractor having a rear and front implement attachment mechanism. Each such mechanism has a hydraulic power lift which acts on it. The power lifts have in common a regulator and control device with a changeover valve. By activating this changeover valve, selectively one of the power lifts can be regulated in conformity with the provided adjustment features, such as the actual values of the position, of the cylinder pressure, etc., while at the same time the other power lift is connected with a control member for random influence of this last-mentioned power lift.