- What is a mechanical pocket watch?
A mechanical pocket watch is a watch that uses a clockwork mechanism to measure the passage of time, as opposed to quartz clocks that work electronically via a small battery, or radio clocks, which are quartz.
A mechanical clock is driven by a main spring that must be wound either periodically by hand or via a self-winding mechanism. Its power is transmitted through a series of gears to drive the balance wheel, a weighted wheel which will swing back and forth at a constant speed.
A device called an escape releases the clock wheel to move a small amount forward with each swing of the balance wheel and move the hands of the clock forward at a constant speed. Relaxation is what makes the 'ticking' sound that one hears in a mechanical watch that works.
Mechanical clocks evolved in Europe in the 17th century from spring-driven clocks that appeared first in the 15th century.
How does a mechanical pocket watch work?
The internal mechanism of this mechanical pocket watch, excluding the face and hands, is called movement. All mechanical pocket watches have these five parts:
- A main spring that stores mechanical energy to drive the watch.
A gear, called a wheel train that has the dual function of transmitting the power of the main spring to the balance wheel and combining the turns of the balance wheel to obtain units in seconds, minutes and hours. A separate part of the gear lever, called keyless work, allows the user to wind up the main spring and allows the hands to move to set the time.
- A balance wheel that swings back and forth. Each turn on the balance wheel takes exactly the same time. This is the timing element of the watch.
An escape mechanism that has the dual function of keeping the balance wheel vibrating by giving it a push at each oscillation and allowing the clock gear to move forward or 'escape' by a certain amount with each oscillation. The periodic stop of the gear at the escape gives the 'ticking' sound from the mechanical clock.
- An indicator wheel, usually a traditional dial with rotating hands, to show the time in human readable form.