Linear actuator no longer needs homing routine

Paul Boughton

Tol-O-Matic is announcing its new Absolute Position Feedback (APF)technology, which is claimed to be the first fully-integrated linear actuator sensor that eliminates the need for homing routines. APF-equipped Tol-O-Matic actuators provide analogue feedback to the controller or PLC to determine actual load position.

Work point variances can also be accommodated throughout the cycle, thereby eliminating stoppages for manual set-ups. Systems with APF provide position feedback as soon as power is applied, allowing immediate resumption from shutdowns, resets and power losses.

The APF option is currently available for Tol-O-Matic BC3 pneumatic and B3S electric series actuators and, unlike fixed-length sensors, can be ordered in incremental stroke lengths from 51mm to 3962mm (2 to 156in).

"APF is fully integrated within the actuator body, eliminating the need for complex mounting and also reducing the chance of damage to the transducer," says Michael Dornfeld, Tol-O-Matic project engineer.

"The technology utilises a non-contact, linear displacement transducer that offers high life expectancy, high speed, high linearity and repeatability compared to conventional linear potentiometers."

Dornfeld adds that because the APF magnetostrictive transducer measures position directly, the effects of screw/nut backlash can be eliminated from position feedback information.

In pneumatic applications using BC3-series actuators, APF can eliminate the need for hard-wired event triggers, and events can be easily programmed using a PLC, without having to manually add or adjust switches.

An analogue signal of 0 to 10V dc or -10 to 10 V dc can be selected (based on the control device used) to make full use of the controller's analogue-to-digital conversion capabilities.

Tol-O-Matic's APF technology is said to open the door to greater productivity in a number of applications that demand load position location at operation start-up, or high-performance/high-volume production, including valve positioning, winding, measurement, stacking, inspection machinery, X-Y positioning set-up, load sensing and assembly machinery.

For more information, visit


Recent Issues