A manual watch operates using mechanical energy stored in a coiled spring, which is then released in a controlled manner to power the movement and tell time.
Manual watches, often called hand-wound watches, require regular winding of the crown to function. This action tightens a coiled spring, known as the mainspring, which acts as the watch's power source.
The Basic Mechanism
At its core, a manual watch works through the interaction of several key components:
- Mainspring: Stores the energy when the watch is wound. As the mainspring unwinds, it releases this stored energy.
- Gear Train: A series of interconnected gears (sometimes called wheels) that transmit the energy from the mainspring to the rest of the watch. The gears that connect the mainspring and escapement turn at various speeds allowing the watch to tell time. This train includes the center wheel, third wheel, fourth wheel, and escape wheel, each rotating at different speeds that ultimately relate to seconds, minutes, and hours.
- Escapement: This critical component is the "heartbeat" of the watch. It receives energy from the gear train in controlled pulses, regulating the release of power from the mainspring and driving the balance wheel.
- Balance Wheel: A weighted wheel that oscillates back and forth at a precise frequency. It is regulated by the escapement and dictates the pace at which the gear train moves, thus ensuring accurate timekeeping.
- Hairspring: A tiny, delicate spring attached to the balance wheel. Its expansion and contraction control the oscillation rate of the balance wheel.
- Dial Train: A separate set of gears driven by the main gear train, specifically designed to move the hour, minute, and (if present) second hands on the watch face.
How it All Connects
When you wind a manual watch, you tighten the mainspring. The unwinding mainspring turns the first gear in the gear train. This energy is transmitted through the series of gears to the escapement.
The escapement allows the escape wheel to rotate one tooth at a time, creating a ticking sound and impulse that keeps the balance wheel oscillating. The regular, precise oscillation of the balance wheel controls the speed of the escape wheel, which in turn regulates the speed of the entire gear train.
Since the gears that connect the mainspring and escapement turn at various speeds allowing the watch to tell time, this controlled motion is precisely translated by the gear train to the hands on the dial, indicating the hours, minutes, and seconds.
Essentially, the winding stores the energy, the gear train transfers it, and the escapement and balance wheel regulate its release to keep time accurately.
