Limit switch design has several key terms. Here is a quick overview of these terms for reference:

Action Travel (pre-travel) - Indicates the distance or Angle at which the actuator on the limit switch needs to travel before the travel switch is touched.

Action Point - Indicates the position of the actuator when the switch contact is moved to the operating position

Release point - Indicates the actuator's position when the contact is returned to its original condition

Differential - The interval or angular displacement (degree) between the operating point and the release point (i.e. the interval between contact trip and reset)

Do you know all the buzzwords about limit switches?

Overstroke - Any movement of the actuator assembly beyond the switch trip point

Initial Bearing - Indicates the bearing of the switch actuator without any external force

Operating force (torque) - Indicates the force required to produce actuator motion (or torque used for angular motion).

Small return force (torque) - Indicates the force (or angular motion torque) required to bring the switch actuator back to its initial position

Total travel - the maximum distance the actuator can travel during its operating cycle

Repeat precision - A measure of the extent to which a limit switch can repeat its characteristics during repeated (successive) operations.