Patent ID: 8615320

Claim:
A machine tool monitoring device, comprising: an identification unit for identifying an unexpected or inappropriate use of a work piece on a machine tool, wherein the identification unit is configured to identify the unexpected or inappropriate use using at least one distance variable, the identification unit configured to identify the unexpected or inappropriate use with the aid of a set of distance variables, wherein identification of the unexpected or inappropriate use is based on a difference between a plurality of distance variables of the set of distance variables; and at least two sensor elements for detecting the at least one distance variable, wherein the at least one distance variable is a vertical distance between at least one of the sensor elements and at least one of: a work piece processing plane and a work piece lying on the work piece processing plane, wherein the at least two sensor elements are each arranged to designate a monitoring area along a conveying direction of the machine tool, and wherein at least two sensor elements of the at least two sensor elements are arranged on a first and second side of a parting plane of the machine tool each for detecting at least one distance variable of the set of distance variables.