Some of the operating elements for wrist watches are the so-called crowns for setting the hands and for winding the movement in the case of mechanical watches, as well as the so-called pushers which serve to initiate, stop or switch functions.
These operating elements basically consist of a shaft which is guided through the wall of the watch case, with its inner end interacting with functional elements of the watch movement and its outer end provided with or connected to a head that forms the actual operating component. A major problem consists of achieving a lasting pressure-tight passage of the shaft through said case wall. In general O-rings made of an elastic material are used for this purpose, but these have the disadvantage that they are rapidly subject to increased material output as a result of the rotation and the axial sliding movement of the shaft, so that the passage leaks already after a short period of operation and hence moisture or water can penetrate into the interior of the watch case.
Precisely this problem was the starting point for the development of our lubricant cell. This is basically a tube which is located between two sealing elements and filled with viscous, paste-like lubricating agents. The two Viton sealing elements prevent leakage and migrating of the lubricating agent. However, it will only fill the microscopic surface roughness of the crown or pusher stem that still remains after the polishing. During any axial or radial movement of the pusher or crown shaft, the sealing elements thus slide over a fine lubricating film. Wear of the sealing elements is thus completely reduced to zero.
This small, useful detailed solution is protected by a utility model and patents for our company.