This is an example of Elgin's grade 478, 16 size, 21 jewel, movement, made about 1924. It is a B. W. Raymond named movement.
This watch had broken pivots on the balance staff, a very common problem as that is the most fragile part or a watch. Here are the components of the balance assembly, including a two-piece double roller.
This is the replacement staff.
Here is where the balance wheel sits. The roller jewel engages the pallet fork as it turns one way and the other. At the other end of from the fork are the pallet jewels which engage the teeth of the escape wheel, one side and the other, allow the mechanism to move forward in jumps - or allowing power to "escape" in small bits.
Contrary to the way it may seem, the speed of the gear train's actual motion is not a significant factor in the accuracy of the watch. A watch that measures time too fast or too slow is usually allowing the train to advance, via the escapement, too frequently, or not frequently enough. This rate is dictated by the mass of the escape wheel and the length of the hairspring, which together from a simple pendulum.
It's all physics and geometry, no magic is required.
This shows installing the double roller on tho the new staff, after riveting the wheel.
This is a lever-setting movement, railroad grade.
No comments:
Post a Comment