Patent ID: 6591217
Filing Date: 2003-07-08
Classification: G01P,H03M

Abstract:
An arrangement for safely monitoring a rotary motion of a shaft, comprising:a shaft being capable of a rotary motion, a drive motor for rotating said shaft, a drive controller connected to said drive motor for controlling said rotary motion of said shaft, said drive controller receiving power from a power supply and a release signal, a measuring means being coupled to said shaft, said measuring means providing a first and a second signal, wherein said first signal includes first instantaneous values and a sine-shaped envelope, and wherein said second signal includes second instantaneous values and a cosine-shaped envelope, said first and second signals representing said rotary motion of said shaft, and an evaluator which receives said first and said second instantaneous values, said evaluator including a comparator which is capable of comparing said instantaneous values using a predefined geometric relation, wherein said evaluator is in the position to stop said rotary motion via a first and a second cut-off path, namely by interrupting said power from said power supply and by blocking said release signal.