Reinventing Draw-Wire Sensors – Introduction

Linear position sensor for subsea and ATEX rated

Perhaps one of the most memorable moments of my career at CPI happened over a decade ago, when CPI was first asked to produce a robust hydraulic position sensor for a large well known maker of construction vehicles and equipment. In their larger machines, rod-type sensors were being used in the control system of long stroke hydraulics but their installation was problematic, and they often failed in rough conditions.

After many months of engineering and testing CPI produced the first version of our SL series sensors. Our new sensor was durable, accurate, and used a well accepted linear position measurement principle, the draw wire.  In our solution however, the draw wire mechanism was completely re-conceived and re-engineered for harsh duty and improved accuracy. The mechanical rotations of the draw wire were ingeniously coupled to an LVDT transducer system so the whole solution was non-contacting and virtually immune to all the environmental hazards, temperature and EMI your average 15 ton wheel loader runs into. The system was so unique and unlike anything that existed that we were able to receive several patents from it.

Proudly we demonstrated our achievement to our client, certain that we were onto something big here. Do you know what they said?   (wait for it….)

“Not high-tech enough”.

Maybe you’ve experienced this: one of those moments when words fail you and you’re quite sure your head will explode shortly.  You see, having witnessed the amount of research into material science, alloy’s, precision engineering, and component testing that went into our sensor, all I could think was “well define high-tech!”.

And so now a decade later, having seen our unique sensor gain wide acceptance in applications more diverse that we ever imagined (including construction vehicles), I’m calm enough to explain in this upcoming series, just exactly what constitutes “high-tech” in our hardened linear position sensor solution, and more importantly, why it outperforms every other sensor technology in the world for extreme duty, long stroke, or subsea applications.

Coming Next:  Can a mechanical draw wire system be “High-Tech”?  (pretty sure you know what we think!)