Plover Tsai: Study on Clocks/Watches

Type of Clocks

1. Lantern clock

Introduced around 1620.
Original lantern clocks were all weight driven.
Occasionally a spring-driven clocks may be found

2. Bracket clock (Spring clock)

3. Longcase clock

Tall, weight driven pendulum clock
The longcase is not to be confused with the regulator clock

4. English dial clock

5. American wall clock

6. Carriage clock

7. French clock with a drum movement

8. Vienna regulator

Made about 1790 and 1910
Normally use a Graham dead-beat escapement and a wooden pendulum rod with large, disk-like bob in polished brass.

以上資料從 BHI 擷取。

判斷擺鐘為 Vienna regulator，答答答的聲音就是 escapement 發出來的。

Escapement

The escapement is THE part of a clock/watch that prevents the weight of the winding mechanism plunging to the floor or prevents the mainspring to relax within seconds and which makes sure, that the pendulum (balance) swings remotely.

因為擺鐘下面有一個擺垂，我又聽聲音，合理懷疑是 Graham escapement

參考資料：

http://www.clockwatch.de/index.html?html/tec/hem/gra.htm ((動態))
http://www.princeton.edu/~timeteam/mainframe.htm ((靜態))

到這邊我們還是不知道擺鐘運作的原理，機械鐘最重要的元素就是 oscillator。擺垂是很棒的 oscillator。但我們也知道光桿擺垂沒有動力的話遲早也停擺，那麼整個故事是怎麼一回事呢？

這樣就很清楚了，有了 framework，接下來每個 module 怎麼實作就各憑本事了。

整個主流程就是：

A motive force drives a gear train
The gear train operates some form of time indication
A speed controller (= escapement + oscillator) controls the speed of the gear train

motive force 大致就是 weights 或 springs。

A weight stores energy by lifting from the ground, and releases the energy as it descends.
A spring stores energy by winding it up, and releases the energy as it unwinds.

Gear train