A very interesting look at some of the most unusual Swiss movements ever, the Tissot cal. 2250 that ran without lubrication. Only the balance wheel and some the the gears were metal, the rest was plastic. Fascinating.
The Tissot cal. 2250, also known as the “Astrolon” or “Sytal”, (an acronym for “Systeme Total d’Autolubrification”) was produced in the early 1970’s. It was available in several variations, with and without calendar. Though it is basically conventional in layout, it is markedly different from other mechanical watches in that most of its components are injection moulded plastic. It was semi-automatically assembled and required no lubrication at all. The parts count was reduced from 91 as found in a standard Swiss movement to 52 in the Astrolon, and no screws are employed at all. The only metal components are the balance assembly, the mainspring and barrel, and the keyless winding mechanism. The train wheels run either in the plastic plates or, mostly, on small metal plugs with fine spigots, pressed into the plates. A nice touch was to make the different components in different colors.
The Tissot “Astrolon” Plastic Watch [4/2/00] [TimeZone]
