PrecisionLine Vario – a metrological masterpiece

Pforzheim (Germany)-based company Kleiner GmbH’s wide-ranging product portfolio  includes micro stampings (uses include plugs in hearing aids), snap domes (found in many keyboards and switches) and lead-frames, which are replacing classical printed circuit boards in many areas. 

The trend towards miniaturization of mechanical, mechatronic and electronic functions is visible everywhere and this is reflected in Kleiner GmbH’s product range. Drastically increased demands on operation, manufacturing accuracy and material properties are the order of the day for Head of Development Stefan Grosskopf: “We often approach the limits of feasibility.”

Testing technology manufacturer Zwick had to meet these new challenges and develop new, high-precision testing systems. Close collaboration with Mr. Großkopf and his team of developers resulted in a version of PrecisionLine Vario which allows testing of snap domes (in two size ranges - small and extremely small) up to 60 Nm, as well as complete switching systems and components up to a nominal load of 500 N. Tests covered include the spring characteristic of snap domes, spring washers and tiny contact springs, plus push-in tests and analysis of push-in zones. If required, the electrical characteristic values for complete switching systems, such as switching moments and switching hysteresis, are also determined. A T-slotted platform allows devices and specimen holders to be installed in the testing machine.

What Mr. Grosskopf has to say:
“The machine is a metrological masterpiece. What impressed me immediately was the patented compensation for load-cell self-deformation and the accuracy of the testing machine. The machine is extremely stiff and displays virtually no hysteresis in the load range  we work in. Using this machine to test components produced by our company enables us to see effects which were previously not visible with conventional testing machines. Even characteristics of springs with a maximum force of 25 cN  (0.25 N) can be measured exactly and reproducibly. The machine helps us to develop production-friendly products and maintain our high quality standards in the face of ever finer tolerances.”