While, as regards the frictioned rings, we have a new type described below:
· This new kind of friction ring has got some balls inside which create a "bearing effect". This "bearing effect" makes the friction very sensitive and this allows the ring to keep the blocking elements underneath the external diameter (while the other frictions are provided with blocking elements that stick out of the external diameter).
Thanks to this fact there will be no more carton dust during the unloading phase.
· The two parts of the ring are made in anodized aluminum so that the friction is lighter than the ones made in steel. Nevertheless, the friction has got a compressive strength which is comparable to the steel one and that's possible thanks to the balls inside the ring because they create an internal reinforcement.
· The rings are provided with a mechanical stop and this allows the blocking elements to expand without ruining the cavity in which they are slotted.
· Patent pending