Industrial procedure for the manufacture of crystals for all kinds of watches and metering devices of different systems (Machine-translation by Google Translate, not legally binding)

摘要

Industrial process for the manufacture of crystals for all kinds of watches and measuring devices, essentially characterized in that the plastic material and the powdered and granulated glass are placed in a plunger coated with an electrical resistance to convert said ingredients into a liquid state. (Machine-translation by Google Translate, not legally binding)