Diagrams

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Labelled plates

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What each of the 13 plates shows

• Pocket watch anatomyThe principal external and case-level parts of an open-face pocket watch: case, crystal, dial, hands, crown, pendant and bow.7 labelled parts — Case, Crystal, Dial, Hands, Crown, Pendant, Bow
• Mechanical watch movementA going-barrel lever movement viewed from the top-plate side: barrel, train, escapement and balance between the plates.8 labelled parts — Barrel, Centre wheel, Third wheel, Fourth wheel, Escape wheel, Pallet fork, Balance & hairspring, Keyless work
• Wristwatch anatomyThe external architecture inherited from the pocket watch and adapted to the wrist: case, lugs, crown, crystal, dial, hands, strap and case back.8 labelled parts — Strap, Lugs, Crystal, Dial, Hands, Crown, Case, Case back
• Clock movementA weight- or spring-driven clock movement: mainspring or weight drive, going train, escapement and pendulum, plus the striking train.6 labelled parts — Weight or mainspring, Going train, Escapement, Pendulum, Striking train, Motion work
• Gear trainThe stepped-up wheel train from barrel to escape wheel — shown here as a live simulator rather than a static plate.5 labelled parts — Barrel, Centre wheel, Third wheel, Fourth wheel, Escape wheel
• EscapementLock, impulse and detachment animated: how a lever escapement meters the train's release in step with the balance.Animated sequence
• Balance assemblyThe balance wheel, hairspring, roller and balance staff — the oscillator that sets a watch's rate.6 labelled parts — Balance wheel, Hairspring, Balance staff, Roller & impulse jewel, Regulator (index), Balance cock
• Fusee and chainThe conical pulley-and-chain mechanism used to equalise mainspring torque across its wind.5 labelled parts — Mainspring barrel, Chain, Fusee cone, Great wheel, Maintaining/stop work
• PendulumThe suspension, rod, bob and compensation elements of a precision clock pendulum.5 labelled parts — Suspension spring, Rod, Bob, Rating nut, Compensation elements
• RepeaterThe striking-on-demand mechanism that chimes the time acoustically via snail cams, racks and hammers.5 labelled parts — Activating slide/pusher, Snail cams, Racks, Hammers, Gongs
• ChronographThe switchable elapsed-time train and its column-wheel or cam-based control system.5 labelled parts — Pushers, Column wheel, Coupling clutch, Chronograph seconds wheel, Heart-piece (reset) cam
• Calendar workThe date-ring mechanism, jumper spring and (where fitted) perpetual month-length cam.4 labelled parts — Hour-wheel take-off, Date ring/disc, Jumper spring, Month-length cam (perpetual only)
• Case anatomyThe construction of a hunter or open-face pocket watch case: back, bezel, cuvette, hinge and closures.5 labelled parts — Bezel, Case band (middle), Case back, Cuvette (dust cover), Hinge

Further reading

Go deeper on this subject

The plates show where parts sit and what each one does; the pages below explain how they work together, in the order a reader would meet them when opening a movement.