DANGER PREVENTIVE CONTROL DEVICE FOR SEQUENTIALLY OPERATING MACHINE

摘要

PURPOSE:To reduce the number of component parts required for the titled machine by a method wherein two bistable circuits, a specific counter, a selecting device and the like are used and the counter is reset by specific input signals and operating position signals. CONSTITUTION:AND gates 7, 8 and 9 are operated by output terminals 0, 1, 2 and 3 of the counter 6 operative through an OR gate 5 and the signals (d), (e) and (f) indicating the sequential operation positions and the counter 6 is reset through a safety position signal selecting device 10 and the two bistable circuits 1 and 2. Further, a start signal (a) generating for a predetermined period of time through a switch (not shown) and the output of the bistable circuit 1 are inputted to an OR gate 3. When the start signal (a) is generated, the counter 6 is released by a clock pulse (b) through the bistable circuit 2 and steps to 1 to zero by a succeeding pulse (b). Thus, when the signal (a) goes OFF before the signal (d) is inputted to the counter 6 after the counter 6 has stepped to 1, the bistable circuit 2 is reset so that the counter 6 returns to zero.