Force bolt at a machine joint has stress strings, linked to sensors, with oscillations to indicate distortion at the bolt through excessive force

摘要

The force measurement system (16), e.g. at a joint in an agricultural machine, registers distortion at a measurement bolt (12). At least one stress string (28,30), within longitudinal drillings (44,46) in the bolt, is linked to a sensor (32.34) as an acoustic alarm, where its oscillations are taken as an indication of bolt distortion.