Toothed belt for non contact measurement of distance and speed of the belt using magnetic material for inductive sensing of the distance travelled using magnetic sensors

摘要

The toothed belt (1) is made of a plastic material or a rubber type material and comprises a carrier (3) and a row of teeth (2) at predetermined spacing. The teeth are augmented with magnetic material (4) such as iron rods or iron powder. The magnetic material allows the distance travelled by the belt to be inductively determined using magnetic sensors. Alternatively holes can be provided between the teeth to enable the travelled distance to be determined using optical sensors. Alternatively markings can be printed on the back of the belt for detection by an optical reflex light box. Alternatively strips of copper foil can be applied to the back of the belt for detection by capacitive sensors.