The rotary limit switch is used to control the movement of industrial machinery. It operates as an auxiliary controller of electrical motors through a power interface, such as a contactor or PLC. Suitable for heavy duty, its shaft is connected to the motor and, after a set number of revolutions, the cams operate the switches, thus starting the predetermined movement. A worm gear and a helical toothed gear combined with one or more pairs of straight toothed gears are used for the transmission of the movement from the input shaft to the output shaft.
Revolution ratios ranging from 1:1 to 1:295 result from the use of different combinations of gear wheels between the input shaft and the output shaft, which is connected to the cams operating the switches.
Transmission and gear driving shafts are made of stainless steel to prevent oxidation and wear. The gear wheels and the driving bushes are made of self-lubricating thermoplastic material, suitably chosen to reduce the wear to a minimum and to maintain the accuracy of the couplings over time. Sintered bronze bushes are moulded into the base of the limit switch to optimise the shaft rotation and to prevent rubbing with plastic material.
Each cam can be set with great accuracy thanks to the cam adjusting screws. The auxiliary switches are of a positive opening type, thus suitable for safety functions. It is available with direct control switches for operating directly on the motor.
The cam-switch sets can be substituted for potentiometers suitable for the connection to electronic equipment.
Materials and components are wear resistant and protect the equipment against water and dust. The limit switch is available with a flange for direct coupling to the motor and it can be customised with labels and colours according to the customer’s requirements.
PF2C is an electromechanical device for low-voltage control circuits (EN 60947-1, EN 60947-5-1) to be used as electrical equipment of machines (EN 60204-1) in compliance with the fundamental requirements of the Low Voltage Directive 2006/95/CE and of the Machine Directive 2006/42/CE.