Controlling carding device using density sensor upstream of feed rolls - to vary feed or delivery roll speeds to ensure uniform density

摘要

The parent patent describes a carding device including a density sensor to measure the density of the fibre lap and continuously adjust the speed of the fibre feed or fibre delivery rolls to maintain the density of the lap constant. The sensor pref. comprises a radioactive source and a radioactive sensor which detects radioactivity passing through the lap in or adjacent to a zone in which the lap passes through a nip formed between a presser roller and a fixed table. In the improvement the density sensor is positioned immediately upstream of the feed rools through which the lap passes into the carding device. The tension on the lap between the fixed table and feed rolls simplifies control of the volume of matl. Since the density of the lap is measured as it passes into the carding device the delay in controlling the fibre feed or fibre delivery rolls doesn' have to be built into the control system.