Case Screws. Modern Casing. The Hunting Case
In the American system of casing movements, the movement was not jointed to the case but held in place by means of case screws. These case screws at first were merely short screws similar to pillar screws and screwed into the top plate so close to the outside edge that the heads projected far enough outside the plate to catch on the case and thus hold the movement in place. At D in figure 8 is shown such a case screw. In the lower plate, that is on the dial side of the movement, was placed a pin, E in figure 9. This pin fitted into a hole drilled in the case directly under the point of the arrow G in figure 10. In this way the movement would he held in the case at two opposite points, the case screw at D and the pin which would be on the dial side and directly under the point of the arrow F in figure 8. This pin also served another important purpose. By means of it the movement was always placed in the case in a fixed position so that the figure 12 on the dial was in exact line with the center of the pendant as shown in figure 10.
Half Head and Full Head Case Screws
Next the case screws were made long enough to extend through the top plate and threaded into the lower plate. These screws were made with half heads, so that by turning the screw half way round, the movement was released and could be taken out of the case. These half head screws however, being of tempered steel, had the effect of a milling cutter and in some instances by much use, the screw would cut through the softer metal of the case making it necessary to put a washer under the head of the screw in order to hold the movement in the case. This cutting of the case by the half head case screws has been overcome by using full head screws instead, and with this style it is best to take the screw entirely out before removing the movement from the case. By half head is meant a screw in which nearly half the head is cut away. Full head screws are those in which the heads are left full round as the screw at D figure 8. At H in figure 9 is a drawing of a full head case screw. At K is shown a full head screw as it appears from above and at L a half head.
Formerly the retail dealer in American watches was accustomed to buy separate movements and cases and then do his own “casing” by which is meant the fitting of the watch movement to the watch case. In American watches this “casing” was not at all difficult on account of the precision with which both the movements and the cases were made. Thus it would require very little skill to fit any standard American made 16 size open face movement into a 16 size open face ease made by some other American manufacturer – sometimes in pendant set movements a slight alteration in the stem or adjustment of the sleeve. In lever set movements it might be necessary to file a slot in which the lever could slide. The Swiss movements, cased in American or Imported cases, presented a more difficult problem on account of their lack of being standardized to the extent that the American products were. Now nearly all American and Swiss movements are being cased by the manufacturer or importer, coming to the retail dealer ready to be delivered to his customers so that the watchmaker has less of this work to do than formerly. However, it will be necessary for you to do some casing in any store but by understanding the relationship of certain parts which will be explained to you, this work should offer very little difficulty.
The Hunting Case
Formerly the Hunting Case was popular in both men’s and ladies watches, but today the favorite in all sizes is the Open Face. By Hunting Case we mean that kind of a case with two lids or backs as shown in figure 11, one of which, on the dial side, can be opened by pressing on the crown at H. The different parts that make up a Hunting Case are as follows: the two backs A and B in figure 11, B on the dial side in the language of the casemaker known as the “front back” and A as the “back back”.
Generally this is shortened to “front” and “back”.
C is the “cap”.
D is the “center”.
E in which the watch glass or crystal is fitted is the “Bezel”.
The two “backs” are hinged to the “center” by what are known in the trade as “joints” as shown at F. The “cap” also is connected to the “center” by means of a “joint”. The “bezel” is snapped on the “center”. G is the “pendant”. H is the “crown”. K is the “bow”. The “stem” by means of which the watch is wound is attached to the “crown”, generally being screwed into that part so that the “crown” and “stem” act as one solid unit. In figure 12 is shown a dial view of the Hunting Case with front opened. In this photograph the letters represent the same parts as in figure 11. Thus the arrow D indicates the center, B the front, K the bow, H the crown, G the pendant, and E the bezel.
Screw Bezel and Screw Bach Cases. Swing Ring Cases
Assembling Fancy Shaped Cases The Fancy Shaped Cases come under the class of "snap cases" and are generally provided with a key or pin on the center which fits into a "key seat" or opening on the bezel or back. In figure 15 is shown a movement in an octagon shaped case
|« Chuck holders, gravers, saw||Open Face Cases. Position of the Lip »|