| 摘要 |
PURPOSE:To detect abnormal envelopes, by providing envelope detectors for moving envelopes and comparing the difference of generation time between respective detection signals with a set value and generating an alarm signal if this difference is larger than the set value. CONSTITUTION:Two switches are provided for detecting an envelope 11, and switch operating lever L are arranged in the direction orthogonal to the advance direction of the envelope 11. When the envelope 11 advances in the normal state, levers L are brought into contact with the envelope 11 simultaneously, and detection signals are generated from switches SW simultaneously. Meanwhile, when the envelope 11 is bent very much, the envelope 11 is judged to be abnormal because of the difference of detection time between levers L. |
