Draw-wires for distance measurement

News Editor

ifm electronic is now offering a range of draw-wire mechanisms that provide a simple, reliable and accurate way of measuring position and distance over long straight spans. Featuring robust construction that ensures reliable operation in demanding environments, even when the draw wire is subjected to continuous strain, the new E614xx mechanisms are suitable for use with almost any encoder that has a 58 mm synchro flange and a 6 mm shaft.

Typical applications include monitoring the height of fork-lift truck forks, the extension of crane booms and the vertical position of trolleys in high-bay warehouses. Essentially, the wire-draw mechanisms comprise a housing containing a spool of wire cable, the end of which is attached to the target object. As the target moves, the spool rotates and this rotation is captured by the encoder that has been attached to the mechanism, allowing position of the target to be evaluated.

The draw wire encoders have high shock and vibration resistance thanks to their magnetic sensing principle and can be used in harsh environments where alternative technologies might struggle.

ifm is currently offering the draw-wire mechanisms in four versions: E61439 which is suitable for cable spans up to 1.9 m with linearity of ±0.02%, E61440 for spans up to 2.4 m with linearity of ±0.1%, E61441 for spans up to 3 m with linearity of ±0.01% and E61442 for spans up to 5 m with a linearity of ±0.01%. Special versions for spans up to a maximum of 15 m can be supplied upon request.