Bonser safety frame for David Brown tractors 850, 880, 900, 950 and 990

Abstract

Strength tests were made using testing apparatus similar to that used by the Swedish National Institute for Testing Agricultural Machinery and the National Institute of Agricultural Engineering, Silsoe, England, to establish whether the safety frame could be expected to protect a driver during an overturning accident. The deformation of the frame during impact and crushing tests was small enough to indicate that the operator would not be crushed during an overturning accident. The tractor was operated, with and without a frame, pulling a cultivator and a trailer, to determine what effect, if any, the frame had on noise levels. No significant change was detected. The frame did not unduly affect accessibility, visibility or maintenance. However, it was impossible to operate the hand-brake on the tractor tested due to the proximity of one of the frame uprights.