Cut Sheet

Volume 8—Sensing Solutions CA08100010E—November 2012 www.eaton.com V8-T12-11
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12.1
Sensor Learning Course
Learning Module 23: Limit Switches, Proximity Sensors and Photoelectric Sensors
Plunger Actuators, continued
Mounting Considerations
When applying mechanical limit switches, consideration of the type of actuation needed,
the mounting locale of the device and the speed of actuation are very important.
Cam Design
The cam angle should equal
the lever arm angle for
applications where the cam
will not overtravel the
actuator. Where relatively
fast motions are involved, the
cam should be of a shape
that does not allow the
actuator to receive a severe
impact, or that releases the
actuator suddenly allowing it
to snap back freely.
Cam Design When using side-push or top-
push plunger actuators, be
sure the cam operates in line
with the push rod axis. Do
not use the limit switch
body to act as a mechanical
stop for the cam in
overtravel applications.
Some other type of barrier
must be provided as the stop.
Lever Type Application
Straight Used where the actuating element travels in same axis as plunger. Available in
standard and extended lengths.
Lever Used in applications where the cam actuates in line with the plunger but may
require a larger differential or where an appreciable side thrust is present.
Roller level Used in applications where the cam will pass by the switch laterally.
Roller plunger Used in applications where the cam may present some degree of side thrust.
Roller helps deflect this.
Cat whisker and wobble stick Typically used in conveyor applications to count objects as they pass by. Can be
actuated in any direction.
Straight
Lever
Roller Level
Roller Plunger
Cat Whisker and
Wobble Stick
48°
48°
48°
Cam