Every steel mill facility has a significant number of spring-driven cable reels in operation.  These are primarily used at the top of overhead cranes, those that have magnets or grapples to move materials, and on transfer cars that move materials horizontally.  Historically, reels on the market retract the cable using a set of concentrically wound springs, like those used in a spring-driven clock.  To get more power, the springs are often ganged together “in parallel” to achieve the needed torque to retract the cable.  The cables involved are often quite heavy to power the magnet or other device.  The cable is quite long — 60–80 feet — and the reel must be able to lift the cable upwards to the spool as the magnet is raised.  Reels in this application operate almost continuously, so the number of duty-cycles required is quite high.
 
The problem with existing spring-driven cable reels is that spring life is limited to roughly 30,000 cycles before one or more of them fail.  It is costly to stock extra spring motors and a major job replace them in the field.  A spring reel failure can cause downtime in critical applications.
 
Engineers at Conductix-Wampfler have developed a radically new spring motor concept: the Linear Spring.  By using a ball screw coupled with a coil spring — the same type used in motor vehicles — a reel has been developed that will offer three-times the spring life before they should be replaced.  In other words, 100,000 cycles versus 30,000.  If a spring ever needs to be replaced, it is an easy matter of releasing the tension and inserting a new one.  The design has been awarded US Patent No. 8888033B2.  Besides the exceptional spring motor life, the rest of the reel is ruggedly built and designed for very demanding conditions found in mills.
 
The new reel — dubbed the RHINOREEL™ — will be introduced at AISTech 2015 at Conductix-Wampfler booth # 2623.