Distance measurement system with limit markers - contains measurement and reference scales with distance and limit markers and associated sensing units

摘要

The system contains a limit marker transducer which stops a moving part when it passes a limit marker. A scale carrier has measurement (4) and reference scale (6) tracks with detectable limit markers (16,16a,17,17a) and associated sensors in a sensing head. A reference unit (12) with reference marker sensors and a measurement unit (10) are attached to the moving part (15) via first and second transfer elements. The units produce reference and measurement marker and limit marker detection signals. USE/ADVANTAGE - For protection of machinery against moving parts moving beyond travel limits of working ranges with a compact, low-cost system of minimal structural cost.