Abstract: The left and right truss rod assemblies of a truss that supports the span of an irrigation pipeline are bridged by a single sensor device. A movable linear connector in the sensor receives oppositely directed loads from axially spaced members of the two truss rod assemblies and provides a linear motion that can be transmitted to a control device to shut down the system if tension force in the truss becomes excessive. Movement of the linear connector is yieldably resisted by a resilient element, which resistance is overcome if and when the tension force in the truss exceeds a threshold level.

Abstract: A flow-through joint in an irrigation machine between the main pipeline section and a swing span, such as a corner span, permits a limited amount of generally linear displacement of the swing span within the joint for speed control or other purposes. A turret that rotates freely on the upright outlet port of the main pipeline section has a pair of coupling assemblies on opposite sides of the upright pivot axis through the outlet port, one of such coupling assemblies having a ball joint and the other being provided with relatively displaceable components. The arms of a connecting yoke on the inner end of the swing span are coupled with the ball joint on the one hand and the displaceable components on the other so as to provide the necessary swinging and pivoting motions while at the same time allowing displacing movement as necessary for control purposes.

Abstract: A compression safety for a span of an agricultural irrigation system detects changes in the condition of truss rods associated with the framework of the span. When one portion of the truss rod assembly goes slack relative to another, such condition is detected by the safety to shut down the entire system. In a preferred embodiment, the safety is mounted at one of the V-braces forming part of the truss framework below the water conduit of the span. Truss rods are connected to and extend in opposite directions from the V-brace, one of such rods supporting a switch of the safety and the other supporting the switch actuator of the safety. The actuator comprises a long tubular member that is supported intermediate its ends by a fulcrum mount at the apex of the V-brace so that the operating lever of the switch is actuated by the actuator when it rocks about the fulcrum in response to a predetermined level of tension changes in the two truss rods.

Abstract: Mobile towers of an irrigation system have drive wheel assemblies that propel the towers along the ground. At least certain of the wheel assemblies may comprise dual wheels that share a common axis of rotation but are separately driven by their own drive motor. By driving the two separate wheels in unison but with their own individual drive shafts, increased ground-engaging surface area can be obtained without a consequential increase in load for any one motor.