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The Visitor 5
Careful inspection at all stages


At every stage of production at Gurnos Works it is apparent that great care is given to inspection. Special inspection benches are located at strategic points in the factory, and every batch of parts is checked and examined by a specially trained staff armed with accurate gauges and very high magnification optical
instruments. This sort of check-up takes place many times as the various component parts of the watch movements pass on, stage by stage, towards the point where they are finally passed as correct for assembly. Defective parts are detected astonishingly quickly, for inspection has the dual purpose of preventing incorrectly made components from passing to assembly, and of locating the error in manufacture which caused them.
Wheel and pinion production follows the accepted lines, and is maintained at a high standard. Wheel blanks are produced from high-quality strip by press-tools that deliver a particularly flat and burr-free output, and after careful inspection, these blanks are mounted on special group-fixtures and cut in batches on automatic machines, a long line of which is kept busy with. this work. One of the most fascinating experiences of the whole tour of the factory is to watch a batch of wheel blanks gradually acquiring their teeth. 
  Pinions and escape wheels are cut on indexing machines. The pinion blanks from the automatic lathes are set up and cut with precision and speed.
  Jewel setting
Every process has something of interest for the visitor, but it is only possible to select a few for brief description. Jewel setting is one, for it is a triumph of good tooling. The setting for the pressed-in jewel is cut to the exact size, and the jewel placed in position by a girl and pressed home by a small, accurately controlled press so swiftly that a number of jewels have been inserted into their plates or bridges before the onlooker has followed the details of the operation. 
The finished part stores is attractive to anyone with a tidy and methodical turn of mind. Large quantities of parts are stored in glass jars which make some sections look rather like a sweet shop. Each calibre of watch has its own colour-code, which appears on each jar or storage bin (some parts, obviously, do not lend themselves to storage in jars) and, indeed, on all labels, tools, drawings, etc. relating to that particular calibre.
  Storage of parts is carefully arranged to give maximum accessibility. Issuing is done in batches, the method of counting small parts usually being by weight on precise ratio scales. In operating these, a sample part is placed in the "ratio" scale-pan to act as a standard of reference, and the parts to be issued are then piled into the weighing pan until the scale indicates that the correct number has been reached. 
  Another type of scale used is the "Shadoweight", in which the reading is given by the movement of an optically projected shadow over a scale, and this gives great precision. It is used for a very small components, and it operates on the counterbalance principle. 

 13 ligne gents wristwatch assembly

In any watch factory, however, the supremely interesting point is the assembly department where all the planning and precise work devoted to the various component parts becomes centred in the working, time-measuring movements. At the Gurnos Works, this division of the factory really is a division, housed in a separate semi air-conditioned and dust-proofed two-storey building behind the machine shops. There is even a small ceremony before one enters, for everyone must (this is an order) put on overshoes that are designed to prevent any dirt that may linger on even carefully-wiped shoes from reaching the spotless floors. 
  There are 7 pages on the visit in 1962. Use the box links below to see the other pages