Abstract: A polymer-lined fluid transmission line includes various structures, including a first polymer-lined pipe, a second polymer-lined pipe, and one or more sleeve retainers installed at a pipe junction between the polymer-lined pipes. Among other things, the sleeve retainers may include one or more protuberances to frictionally engage the polymer-lined pipes or a one or more portions that protrude into a space between the polymer-lined pipes to help retain and protect polymer sleeves.

Abstract: A polymer-lined fluid transmission line includes various structures, including a first polymer-lined pipe, a second polymer-lined pipe, and one or more sleeve retainers installed at a pipe junction between the polymer-lined pipes. Among other things, the sleeve retainers may include one or more protuberances to frictionally engage the polymer-lined pipes or a one or more portions that protrude into a space between the polymer-lined pipes to help retain and protect polymer sleeves.

Abstract: An irrigation system having a pipeline supported by one or more towers includes an improved truss connection system having a means for readily adjusting a crown height of the pipeline. A pair of cooperating members define a joint which selectively couples headed ends of adjacent truss rods together to form a truss rail of a truss system that supports the pipeline. A single fastener may fasten the cooperating members, a strut, and a cross-member together at the joint. A length of the truss rail may be decreased by holding the truss rods closer together. In an aspect, the headed ends of the adjacent truss rods are held closer together by inserting a shim in one of the joints. Decreasing the length of the truss rail increases the deflection of the pipeline and raises the crown height.

Abstract: Systems and methods for determining optimal water capacity or distribution for each of a plurality of sections of a field to be irrigated by an ancillary span of an irrigation system are provided. A path is determined for a steering tower of the ancillary span that is comprised of a plurality of position-based coordinates. The position of the ancillary span steering tower (and thus the position of the ancillary span) relative to the determined path is always known and, accordingly, the optimal water capacity or distribution for the needs of its location can be readily determined based upon a calculated area factor percentage.

Abstract: A self-propelled irrigation system has an elongated pipeline supported above a field by a plurality of drive towers. The drive towers each have a base beam assembly, a tower structure extending above the base beam assembly for supporting the elongated pipeline, and a plurality of drive wheel assemblies for moving the base beam assembly over a field. The drive assemblies include first and second drive assemblies mounted to respective ends of the base beam assembly. At least one of the drive towers also has a third drive assembly mounted to the base beam assembly between the first and second drive assemblies. The base beam assembly supporting the third drive assembly is articulated between its first and second ends and pivotally connected to the lower ends of the tower structure to allow the third drive assembly to move vertically relative to the first and second drive assemblies when traversing uneven terrain.

Abstract: A GPS-based control system for irrigation systems includes a power supply, a nonvolatile memory for storing a first set of coordinates corresponding to a reference position for the irrigation system, circuitry for receiving GPS data and using the data to generate a second set of coordinates corresponding to a current position of the irrigation system, and a microprocessor for calculating the azimuth and the distance between the reference position and the current position using the first and second sets of coordinates. The control system communicates with a main controller of the irrigation system to control a function of the irrigation system, such as stopping, reversing, end gun operation, application rate, or other auxiliary output, at a selected distance or azimuth value of the current position relative to the reference position. The control system can be used with either a center pivot irrigation system or a linear move irrigation system.

Abstract: A guidance system for controlling the steering of a swing arm on a center pivot irrigation system is provided through the use of two satellite signal receiving antennas associated with a drive tower for the swing arm. The signal receiving antennas are mounted from the swing tower so that one of the antennas is in a position forwardly of a steerable wheel for the tower and the other antenna is located in a position rearwardly of the steerable wheel. The signal receiving antennas are mounted in such fashion that they rotate in a direct relation to the steering of the steerable wheel so as to provide position information for the steering of the drive tower that more efficiently and effectively maintains the drive tower on a desired path of travel.

Abstract: A guidance system for providing a steering control for a swing arm on a center pivot irrigation system is provided through the use of two satellite signal receivers. A first signal receiver is located at the center pivot to provide calculated position information for a comparison with the known position of the center pivot. An error signal is generated and is utilized to adjust position information provided by the second signal receiver to produce an improved position information for the swing arm. Such improved position information is compared to the desired path of travel for the swing arm and a steering signal is generated therefrom, which steering signal controls the steering of the swing arm along its desired path of travel.

Abstract: A guidance system for maintaining a lateral move irrigation machine along its intended path of movement. The center support tower of the machine carries a guide arm which is pivotal relative to the tower about a vertical axis. A guide wheel on the arm travels in a furrow which is formed in the field to extend in the intended direction of travel of the machine. The guide wheel remains in the furrow so that if the machine departs from the desired path, relative rotation occurs between the tower and guide arm. A switch actuator is then pivoted in a direction to open a switch which deenergizes the drive motor of the end support tower which is furthest ahead.