Which method uses limit nuts traveling on the limit shaft to mechanically trip limit switches?

Which method uses limit nuts traveling on the limit shaft to mechanically trip limit switches?

• A. Limit nuts traveling on the limit shaft will mechanically trip limit switches to stop the gate at the desired position. Must be a minimum of two limit switches, one at each end.
• B. Use a timing chain driven by a secondary sprocket on the drive shaft rotating a timing sprocket which in turn rotates a limit shaft.
• C. Rely on motor run times, positioning systems, or some type of counter to determine the limits.
• D. Electronic sensors and programmable logic determine the travel limits.

Answer: (A)

This method provides a direct, purely mechanical way to define end positions. Limit nuts ride along a limit shaft as the gate moves; when a nut reaches the actuator for a limit switch, it physically depresses the switch, causing the motor to stop at the end of travel. Using at least two limit switches—one at each end—gives defined stops in both directions and adds safety by preventing overtravel if one side fails. This is different from methods that rely on timing, run times, or electronic sensors and logic, which depend on software, timers, or sensing rather than a hard mechanical stop. The timing-chain approach is still motion-based but uses a different mechanical arrangement and doesn’t involve nuts sliding on a shaft to trip the switches in the same direct way.

This method provides a direct, purely mechanical way to define end positions. Limit nuts ride along a limit shaft as the gate moves; when a nut reaches the actuator for a limit switch, it physically depresses the switch, causing the motor to stop at the end of travel. Using at least two limit switches—one at each end—gives defined stops in both directions and adds safety by preventing overtravel if one side fails. This is different from methods that rely on timing, run times, or electronic sensors and logic, which depend on software, timers, or sensing rather than a hard mechanical stop. The timing-chain approach is still motion-based but uses a different mechanical arrangement and doesn’t involve nuts sliding on a shaft to trip the switches in the same direct way.