ROLLER

In watchmaking, the Roller is a small rotating part, cylindrical or conical in shape, made of a Material that is hard and resistant to wear — synthetic corundum (Ruby / Jewel), hardened Steel or hard Metal. Its function is to replace sliding friction with rolling friction, which is far less dissipative: by rolling rather than sliding, the Roller minimizes energy loss and wear at the point of contact. It is found in particular in certain Automatic winding mechanisms (roller-type reversers), where Rollers locked in one direction and free in the other convert the rotor’s oscillations into unidirectional rotation, as well as in various devices where a Roller acts as a follower for a Cam or rolling support. The use of the Roller illustrates a constant preoccupation of horology: reducing friction to improve efficiency and longevity, favoring, where possible, rolling over sliding motion. Its Hardness and its Polished finish determine its efficiency and durability.