Limit Switch

(redirected from limit switches)

limit switch

[′lim·ət ‚swich]
(electricity)
A switch designed to cut off power automatically at or near the limit of travel of a moving object controlled by electrical means.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Limit Switch

 

(or end switch), an electrical device used in switching control circuits of electrical machine drives or their elements at certain points of their motion.

Limit switches are actuated by the motion of the mechanism itself, usually at the end of its travel or at a predetermined point on the path of its motion. For example, in hoisting machinery a limit switch disconnects the motor and applies the brake upon approaching the end point, thus protecting the mechanism from damage. Limit switches may be of the contact or contactless type. According to their design they are classified as pressure (push-button), lever, shaft, and rotary switches.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

limit switch

An electric switch, operated by a power-driven machine or by the movement of the car which it drives, which alters or controls the electric circuit associated with the machine, e.g., a switch which slows down and stops an elevator car or dumbwaiter car automatically at or near the top or bottom terminal landing; operates independently of the device which normally controls movement of the car.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
Fitted with an electric stop function as standard equipment on the version B, the safety of maximum upper and lower positioning of the hook is ensured by these electric limit switches and the switches themselves activated in turn by two rope slack stops.
Limit switches are easily mounted and feature an adjustable actuating arm for movement in one direction (such as up and down).
The IN65 series of standard limit switches available from Altech Corp.
That plate would compress the springs onto four limit switches wired to a safety mat control unit, which would stop the molding machine immediately.
The optional microelectric actuator determines accurate positioning without limit switches or user adjustment.
Don't bypass limit switches. Limit switches can take a beating during travel and then they stop working.
There are two limit switches, zero limit trip switches and the count limit trip switch.
Emerson Process Management has expanded its Smart Wireless solutions family with the release of the Fisher[R] 4320 Wireless Position Monitor with On/Off Control Output Option, which changes the economics of automating discrete valves as an alternative to solenoids and limit switches. Project cost and project time are reduced by minimizing engineering time, materials, control system I/O, and installation labor.
For safety, the saws are equipped with a safety enclosure monitored by limit switches. The machine cover must be closed for the saw to cycle.
The THLS-8000 provides a far superior level of performance than existing electro-mechanical type high limit switches at a competitive price.
Products have IP 66 sealing against dust and heavy seas, internal limit switches, and optional potentiometer feedback.