Restoration of a Miniature Patek Philippe
By Ernest R. Tope CMW
Making
the bezel and fitting the crystal were fairly strait forward and
familiar tasks but making and fitting the tiny cylinder was more
challenging. The following is a chronicle of the
process of making the cylinder. Some technical
observations have been added. I hope you will
find the information informative and entertaining.
The cylinder escapement is not rare. Invented by Thomas Tompion in the later 17th century, it was the first improvement over the verge escapement. Millions of cylinder watches have been produced. Although it is considered inferior to the more detached lever escapement, it is capable of respectable performance in practical use. Unfortunately many modern watchmakers do not respect them. One thing is for certain. Craftsmen should be familiar with its function before attempting to provide service for them.
Some watches were constructed using a piece of ruby or sapphire as the cylinder section of the balance staff (see below). More commonly the cylinder is a small hollow tube of steel that forms the very center of the balance assembly of a cylinder escapement watch. A portion of the tube is cut away allowing the teeth of the escape wheel to pass through. As these teeth go by the lips of the cylinder they push the cylinder, first one way then the other, causing the balance to swing like the pendulum of a clock. It is a dead-beat escapement with no recoil. read more