Device for monitoring the location of a tool or tool holder on a work spindle

摘要

A measuring unit (11) arranged at stator (6) has receiving unit to receive reflected electromagnetic signal from channel portion (8) in work spindle (1). A signal processing device determines the position of tool/tool carrier with respect to work spindle, based on reflected signal. A bi-directional symmetrical passive microwave coupler has two coupler portions arranged at channel portions (8,10) in spindle and stator such that two coupler portions are opposingly arranged in preset angular position with work spindle for transmission of microwave signal through air gap (7).