Safety ensuring apparatus

A safety ensuring apparatus comprising:

• a rotation detecting means detecting rotation of a movable section and outputting a detection signal corresponding to a rotation rate thereof;
• a rotation monitoring circuit, to which said detection signal from said rotation detecting means is provided, outputting a rotation-presence signal when said detection signal indicates that said movable section is rotating;
• a rotation stop monitoring circuit, to which said detection signal from said rotation detecting means is provided, outputting a rotation stop signal when said detection signal indicates a rotation rate lower than a predetermined rotation rate;
• a movable section control circuit using at least either of said rotation-presence signal or said rotation stop signal and an external command signal for input signals, to control said movable section with logic thereof, with;
• said movable section being enclosed by a fence and a door at a portion of said fence, and;
• said door being provided with a locking device which is controlled by said movable section control circuit, wherein:
• said movable section control circuit includes an operating switch, a door switch and a means for switching;
• said operating switch outputting either a movable section ON signal or a movable section OFF signal;
• said door switch outputting an ON signal which indicates that said door is open, and;
• said means for switching constitutes a self-holding circuit which uses an AND signal constituted of said movable section OFF signal from said operating switch and said rotation stop signal as a reset input signal and an OR signal constituted of said ON signal from said door switch and said rotation-presence signal as a trigger signal to provide said locking device with a control signal.