Cut Sheet

V8-T12-10 Volume 8—Sensing Solutions CA08100010E—November 2012 www.eaton.com
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12.1
Sensor Learning Course
Learning Module 23: Limit Switches, Proximity Sensors and Photoelectric Sensors
Rotary Lever Actuators, continued
Plunger Actuators
A typical plunger actuator
functions something like this:
a cam or plate hits the end
of the plunger, which is
pressed in and operates the
contacts in the switch.
A plunger actuator is the best
choice to monitor short,
controlled machine
movements, or where space
or mounting restrictions will
not permit the use of a lever
actuator.
Lets take a look at the
different plunger actuator
types available.
Plunger Actuators of Various Limit Switches
Lever Type Application
One-way roller Used with reversible cams where operation in one direction only is required.
Rod or loop Used where unusual shape is required. Rod is typically made of steel or nylon.
The loop is made of Nylatron.
Spring rod Used on conveyors where jam-ups may occur. Flexible rod moves in any direction
and eliminates damage to arm or switch.
Rod or Loop
Spring Rod
One-Way Roller
Lever Type Application
Top push rod Actuation must be done in line with plunger axis. Care should be taken to avoid
exceeding the overtravel stated by the manufacturer. A mechanical stop should
be used where the possibility of overtravel exists.
Side push rod Should be used where the mounting permits operating from the side only and not
the top. As with the top push rod, avoid exceeding recommended overtravel.
Available in both momentary and maintained styles.
Top and side push roller The function is similar to push rod styles, except there is a roller attached to the
end of the rod. Typically used where a lever arm will not fit for lateral actuation.
Roller can be positioned either vertically or horizontally.
Pin Most often used where extremely small differentials and operating forces are
required.
Top Push Rod
Side Push Rod
Top and Side
Push Roller
Pin