The new SICK|STEGMANN BTF/PRF range of wire driven incremental and absolute encoders provide linear measurement up to 50 metres with a resolution of 0.025mm. They are quick and easy to fit, (just bolt on the stationary part, pull out the wire and hook it onto the moving part) and are ideal for applications such as crane, drilling and excavator systems, presses, punching and injection machines, weir systems and locks, high-bay shelving, theatre stages, woodworking and stone processing machines, medical equipment and many others.

Each unit consists of a high quality incremental or absolute encoder coupled to a robust wire drive mechanism. The drive mechanism contains a precision drum onto which a stainless steel measuring wire wraps. The wire is kept in constant tension at all speeds up to 4m/sec by a robust and stable coil spring. As the wire is pulled from the drive, the drum turns the rotary encoder to produce a signal proportional to the linear movement. As the drum turns, it travels across the mechanism to ensure that there is no overlapping of the measuring wire and that system accuracy is maintained.

The drive mechanism is fitted with a scraper to keep the wire clean. Any remaining dirt and moisture is then removed by a set of brushes and a grease chamber before it enters the wire drive. These ensure that the wire drive has a long and reliable life even in the most arduous of applications, such as steel works or mobile cranes.

Interface options are available to suit all applications. For incremental encoders, these include HTL or TTL signals. For the absolute encoders, SSI, Parallel, Profibus-DP, Device-Net or CANopen outputs are available.

All these benefits are certain to ensure that the new Sick|Stegmann BTF/PRF encoders become a very popular addition to the existing range of measuring devices available from Sick Ltd.