The design and performance of a gimbal-type mounting for sprayer booms 1. Development procedure

Abstract

A spray boom suspension comprising horizontal and vertical pivots through the centre of gravity of the boom was developed. With this pair of mutually-perpendicular pivots—a gimbal-type of mounting—the boom was restrained in both planes by tension springs and movements were restricted by viscous dampers. Measurements were made of its effectiveness in reducing undesirable spray boom movements. Comparability of test conditions was ensured by making runs over a standard bumpy test track. The horizontal pivot considerably reduced vertical boom tip movements and the vertical pivot reduced the yawing movement of the boom. It was recognized that the values of spring stiffness, damping coefficient and boom inertia profoundly affected behaviour and that optimum values of each would more effectively be determined by analytical than by empirical methods. The trial arrangement of the gimbal mounting was more effective in reducing transmission to the boom of the rolling and yawing movements of the sprayer frame than both a commercial, vertically-sprung suspension and a simple, experimental, pendulum arrangement.