Page 6 - MICRO SWITCH Hermetic Sealed Basic Switches

HM Series

ELECTROMECHANICAL SWITCHES Operating Position (O.P.) – Position of Overtravel (O.T.) – Plunger or actuator
Definitions below explain the meaning of switch plunger or actuator at which point travel safely available beyond operating
operating characteristics. Characteristics contacts snap from normal to operated position.
shown in tables were chosen as most position. Note that in the case of flexible Pretravel (P.T.) – Distance or angle trav-
significant. They are taken at normal room or adjustable actuators, the operating eled in moving plunger or actuator from
temperature and humidity. These may vary position is measured from the end of the free position to operating position.
as temperature and humidity conditions lever or its maximum length. Location of Release Force (R.F.) – Amount of force
differ. Sketches show how characteristics operating position measurement shown on still applied to switch plunger or actuator
are measured for in-line plunger actuation. mounting dimension drawings. at moment contacts snap from operated
Linear dimensions for in-line actuation are Operating Force (O.F.) – Amount of force position to unoperated position.
from top of plunger to a reference line, applied to switch plunger or actuator to Total Travel (T.T.) – Distance from actuator
usually the center of the mounting holes. cause contact ‘‘snap-over.’’ Note in the
case of adjustable actuators, the force is free position to overtravel limit position.
Differential Travel (D.T.) – Plunger or measured from the maximum length posi-
actuator travel from point where contacts tion of the lever.
‘‘snap-over’’ to point where they ‘‘snap-
back.’’
Free Position (F.P.) – Position of switch
plunger or actuator when no external force
is applied (other than gravity).
Full Overtravel Force – Force required to
attain full overtravel of actuator.

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