GLOSSARY

Brief Glossary of Jewellery & Horology Terms

A part of the escapement of the same name, so called because (you guessed it) it looks like an upside down anchor. (It is the grey piece with the 2 red stones in the above illustration of the escapement) This is the frame which carries the two pallet stones in a Lever escapement. It is this part of the watch which release one tooth at a time the escape wheel and whihc also gives the impulse to the balance

pallet frame, jewelled-lever

This is the spindle element of a clock/watch wheel-set. It is the (usually) steel spindle on which the wheel, and pinion, are mounted and which has the bearing surfaces (pivots) at each end.

Axle,pinion,shaft

Balance

This primary part of the regulating element of the timepiece. It is the *wheel which rotates rapidly back and forth. It controls the rate of release (or 'going') of the clock or watch
* Note: A Balance is a wheel in most cases, but could be a bar with, or without weights.
See "Foliot"

Oscillator, flywheel

Balance Spring

This is the heart of the regulating element of the timepiece. A very fine spiral spring, one end of which is fixed to the balance and the other end to the frame, it is this which with the balance wheel forms the regulating oscillator to control the release of energy from the mainspring.

hair-spring, "wire of the wee oscillator-thingy" ...duohh!

Balance Staff

The Arbor on which the Balance (whether a wheel or a bar)is Mounted

Bezel

A ring, usually of brass on clocks, which surrounds the dial and is used to hold the glass. On watches it is similar but is usually machined as part of the case.

Glass-ring

Bolt Ring

A jewellery catch in the form of a circle with a section that opens when a finger is used to slide back the 'bolt'. The common type of 'catch' found on chains, etc.

Catch, locking piece

In watches, this is the 'Crown' by which the wearer sets the time and/or winds the watch.

Crown,winding bit,winding wheel

Button & Stem

This refers to the Button (more correctly this is the 'Crown') of a watch along with the specially shaped 'arbor' ('Stem') used to transfer the movement of the button/Crown to the internal mechanism of the watch, as in setting the time, or winding the mainspring.

Crown,Winding axle,hand setting lever

Chapters

The hour numerals on a dial

Chapter Ring

That element of the clock's overall dial, on which is marked, or applied,the chapters.

Clepsydra

Literally: Thief of Water. One of the earliest forms of clock which consisted of little more than a leaking canister. The container was filled with water and it took a measured time to empty.

Chronograph

A high -calibre watch used for timing intervals. Usually comprising multiple dials on the face to record various timing elements (e.g. minutes elapsed) it has a a centre sweep-second hand which can be controlled by a stop, start, and reset-to-zero buttons

Chronometer (English)

A Chronometer is basically a watch or clock which offers superlative timekeeping regularity. In England it is defined as a mechanism having a Spring-Detente escapement, which is a form of 'extra' detached escapement where the balance receives impulse only every alternate arc... (i.e. imagine a watch which only 'ticks' rather than 'tick-tock's). For a graphical look at Escapement types you might like to visit Mark Headrick's website where he has created excellent animated GIFs of each of the main escapement. Mark has labelled the Spring-Detente as the 'Chronometer Escapement' Click Here to view the 'Spring-Detente' or 'Chronometer' escapement

Chronometer (Swiss)

In Switzerland the term Chronometer is reserved for any timepiece which meets certain accuracy standards. Therefore, a Swiss Chronometer can have various types of escapement with the most prevalent being the 'standard' Jewelled Lever. Only watches which have been certified as having passed the timekeeping standards are allowed to be called Swiss Chronometers

Cock

A 'bracket' or 'bridge' device which is screwed to the plates of a clock, or watch, and whcih holds the end pivot point of an Arbor.

Bridge,bracket,finger

Collet

On a timepiece it can be a brass collar used to fit a wheel to its arbor; but is more commonly the small ring of brass fitting over the balance staff, which serves as the anchorage of the inner terminal of the hairspring;
When used in discussion of a Lathe it is a chuck which is partially "split", or cut in three, equally spaced parts. Used to hold bar material to fine tolerances

Contrate Wheel

Usually found in 'Carriage' style clocks.(Those with a Platform Escapement).This wheel has its teeth cut at right angles to the plane of the wheel itself. This allows the transfer of motion to be passed through 90 degrees from the 'usual' plane of motion.

Bevel or Bevelled Wheel

Crown

The Button of the watch winding and hand setting mechanism.

Button

Dead Beat

A dead beat escapement is one where no 'backward movement' (or recoil)is imparted to the escape wheel. It is unlikely that the retailer or Trading Partner is ever likely to need to use this term

Detent

A locking device. Usually in clockwork this is a curved 'arrow-shaped' piece held against a wheel by the action of a spring to lock the wheel in place temporarily.

Often confused with Detente, which is a specialised form of escapement used within English Chronometers

Dome

In clocks it is the glass covering for such as Skeleton Clocks. (Note: Do NOT send the dome with any clock for repair). In watches it refers to the height of the watch glass, or crystal, above the face of the dial. As in "High Dome" and "Low Dome". A Low Dome crystal has its outer surface level with the edges of the Bezel, whilst a High Dome has a vertical step away from the Bezel to give increased clearance to the hands of the watch.

Ebauche

An unfinished or 'rough' movement (of a watch). Unfinished is a relative term and an ebauche is in fact complete from the factory but minus it's hands, dial, etc.

Movement, mechanism, watchworks

Escapement

This is the link between the going train (or so-called gear train) and the pendulum or balance. It is through the escapement that the impulse is given to the pendulum or balance, and through which in turn the regulation of the timepiece is achieved.

In watches... oscillator,regulator,anchor

Fly

A fan-like device fitted to the Arbor of a part of the clock (usually the striking train) which is used to govern, or regulate the speed of the trains release

Governor

Foliot

A Bar balance used with the Verge escapement found in very early clocks (15th to 17th century)

Fusee

This is the device in a clock or watch which is placed between the barrel containing the mainspring and the rest of the train. It is connected to the Barrel by either a gut line or a chain. The name fusee comes from the medieval Latin fusata which means a spindle full of threads, and this is what the fusee resembles. It looks like a cone-shaped screw. It is in reality a clever style of continously variable gearing used to even out the pull of the mainspring as it unwinds thus imparting a smooth amount of power to the train.

Gathering Pallet

A single leafed pinion, used in rack-striking of clocks etc. This 'gathers' or lifts the rack one tooth at a time. Used to regulate the number of times a bell is struck to represent the hour of day.

Going Barrel

The mainspring of a clock or watch is contained within a 'barrel'. Barrels can be of 2 types... one being plain and connected to a Fusee, the other has a wheel attached to it, or the teeth of a wheel cut into its rim. This latter is a going barrel, one which incorporates the Great Wheel.

Going Train

This is the train of wheels and pinions through which the hands are driven. Strcitly speaking it does not include the Escapement which is a part of the overall movement, but which has a different purpose than driving the hands.

This is the tiny 'push' that the balance or pendulum receives from the mainspring, (via the escapement), which keeps it in motion. Without impulse the arc or rotation of the balance/pendulum would continually decrease until eventually coming to rest, at which point the timepiece stops.

Impulse face

Any part of the Escapement which receives an impulse from the escape wheel. The retailer/partner should never need to refer to this in their everyday dealings. It is a technically related term.

Incabloc

Trade name for a specific form of anti-shock protection for the extremely fine balance staff pivots

Isochronism

The quality of keeping equal-time during the normal run of the power source (e.g.mainspring)

Jump Ring

A simple circle of silver or gold used to link 2 parts of a chain together. Normally soldered these are designed not to be opened after fitting, unlike a Bolt-ring.

Link,split ring

A small carriage which carries the escapement and rotates in order to even out the discrepancies caused by positional errors (causing a watch to gain or lose time when it is worn predominantly in one position). Invented by Bahhne Bonniksen, a Lecturer at the Coventry Technical School, 1893

Carousel, Tourbillon, Karousel

Lantern Pinion

This is a rudimentary, but still very efficient, form of pinion used to drive wheels in a Going Train (Note: Pinions always drive wheels, not the reverse). This form, rather than having leaves which are cut into the steel of the arbor, consist of a circle of pins held between two flat disks. It resembles a small circular cage mounted upon an arbor.

Cage

Lever

The part in a lever escapement assembly which rocks back and forth imparting impulse to the balance wheel and which carries the pallet stones(or pins) which lock and release the escape wheel. (See escapement in image above).

Minute wheel

The wheel in the dial train that connects the cannon pinion (which carries the minute hand) to the hour wheel

Motion Work

The wheels and pinions mounted behind the dial, which drive the hands of a timepiece, and usually incorporate the final 12:1 reduction ratio.

Overwound

Aaarghh!
The amateur and publics' favourite expression of why a watch or clock isn't working; ... and the professionals most hated phrase.
IMPORTANT NOTE: ...if you want to be taken seriously by the professionals you MUST NEVER use this phrase.
There is generally no such thing as "overwound"!
This phrase is guaranteed to give a professional watchmaker that hideous sinking feeling in the pit of their stomach. Especially when combined with the other gut wrencing statement.. "Honestly, it's not really needing much to fix it because I've already given it a spray of *paraffin/*WD40/*petrol/*diesel ...it's just overwound!". *Delete as appropriate. Aaaaaarrrrgghhh!

Pallet

The parts of the escapement upon which the escape wheel acts. On some escapements one part may be locking and the other for receiving an impulse.

Lever,jewel-stones

Pinion

A wheel with a few teeth called leaves. (Teeth are only on wheels, never pinions). Normally, except in the case of Lantern Pinions, the leaves are cut from the same steel as the Arbor. The pinion is the second part of the Wheel-Pinion pair which creates the ratio reductions used to transfer power efficiently from the mainspring through the Going Train.

Gear,spur-wheel

Platform (Escapement)

In the case of Carriage clocks, etc; this is an escapement mounted horizontally atop and across the plates of the clock movement. This carries a balance wheel, escape wheel and various forms of escapement (usually Lever or Cylinder) and recieves it's impulse power via a Contrate Wheel.

Bridge escapement

Regulator

Part of the balance assembly of a watch (or clock with platform escapement). It looks like a small Tennis Racquet and has vertical pins which straddle the hairspring. When the regulator moves towards the stud, the effective length of the hairspring is made longer and the balance slows in speed; when the pins are moved farther from the stud, the hairspring is made shorter and the watch goes faster

Repeater-

A watch or clock whichs rings the last significant time period when a push piece is activated. They can be either Hour, Quarter, or 'Full' (minute) repeaters.

Rose cutter

A hollow, steel tube with cutting teeth around its top

Roskopf watch

A particular design of watch invented by the German watchmaker Georges-Frederic Roskopf (1813-1889). He produced the first cheap watch in 1868, which won a bronze medal when it was exhibited at the Paris Universal Exhibition of that year. Roskopf's design was ingenious. The barrel takes the place of the traditional centre of the movement (i.e. it is a watch with no separate centre wheel). The dial train (hour and minute wheel assembly) being actioned via the minute wheel which is carried atop the barrel cover. Most importantly, to save costs considerably he simplified the escapement, replacing the cylinder of the time with a form of pin-pallet which was much cheaper to make. 'Oris' used to be famous for these cheap style watches prior to relauncing and rebranding themselves in the 1990's as a maker of quality timepieces.

Run

Is a term applied to the sliding action of a gear tooth caused by draw (or reverse angle) of the landing face. It is also the action of the pallet in a jewel-lever escapement which pulls lever assembly towards the banking pin.

Safety roller

Part of the escapement of a watch, etc. It is the small, crescent shaped disc above the 'impulse' pin (or roller). Once assembled it is rarely encountered as a soure of errors, even in the trade.

Screw-head tool

A small tool used to polish the tops of screw-heads, especially for use in clocks

Screw-head file

A knife-edged file for slotting the screw-head

Screw-plate

A steel plate with varying sized holes, each threaded with a cutting edge, used to form watch screws

Setting lever

The arm (detent) which fits into the slot of the stem and operates the clutch lever

Set-up

This is the amoount by which a spring remains wound when the clock is run down. Set-up is means of pre-tensioning a mainspring in order to get useful power from it during its entire wind-unwind cycle.

Sidereal time

The standard of time used by astronomers. A sidereal day is 3 minutes, 56.9 seconds faster than a mean solar day

Springing

The act of co-ordinating a hairspring with a balance so that the vibrations will equal a given number per hour

Spotting

To decorate a plate or wheel by a series of equally spaced spots or whirls made by a revolving abrading rod

Stake

A steel die holder, bench anvil, or rest

Star wheel

A steel wheel used in chronographs and alarms to lift levers

The squared shaft going through the winding pinion and clutch wheel onto which the 'Button' is screwed. Used to wind the watch and set the hands.

Step chuck

A lathe chuck with steps of graduating diameters used to hold wheels or other fiat, round objects

Stop-work (Geneva Stop Work)

The mechanism on a barrel of a watch or clock that permits only the central portion of the mainspring to be wound

Stud

The small metal piece of the balance cock into which the outer end of the hairspring is attached

Tail-stock

The body on the lathe bed opposite the head-stock used to support work held between centers

Tempering

A method of preparing metal to a desired hardness by the application of heat

Third wheel

The train wheel between the center and fourth wheel

Timing screws

Tiny screws mounted in the rim of the balance to decrease or increase the effective diameter in order to retard or advance its vibrations (see the illustration at the top of this page)

A form of positional compensation in which the escapement, mounted on a carriage attached to the fourth pinion, revolves around the stationary fourth wheel

Train

A number of wheels and pinions geared to one another. In watch and clock work this is generally the collection of the clockwork mechanism.

Movement, gearbox, gearing, wheelset

Tripoli

A decomposed siliceous limestone used as a polishing powder

Tripping

A malfunction caused by the failure of the escape tooth to lock upon the locking surface of the pallets

Turning

The work performed upon objects held in the lathe while it is turning

Turns

A small hand-powered (bowed) lathe with dead centers

Umbrella chuck

A split cone step chuck with graduating diameters. Used to hold small, round bezels and rings. The gripping action is to spread the chuck by pulling the underside of the cupped back against the head-stock spindle axle

Up-and-down indicator

The semicircular dial on chronometers that tells how much the mainspring has been unwound and thus indicates when the spring should be wound

Verge

An outmoded recoil frictional escapement with a crown escape wheel and pallets set at right angles to the axis of the escape wheel

Vibration(s)

In watchwork this refers to the oscillations of the Balance wheel. By listening to the vibrations of a watch, using expensive specialist timing equipment, the regulation of the watch can be printed out onto a paper strip. This strip can show the efficiency of the escapement, but also more importantly depicts the rate of gain or loss of the timepiece.
KlokWurX always include the printout from the timing machine examinations with all watch repairs they undertake. This important evidence demonstrates the quality of timekeeping to be expected following our repairs. (Note: Like an MOT examination for a car, the results of this test are only guaranteed on the day they were taken. Although they should remain valid for some months following the initial repair, elements outwith our control will effect the results; ...e.g. fresh dust ingress to the watch after cleaning)

Vibrating tool

A master balance of certified accuracy as to vibrations per hour which is mounted in a box with glass top. The box may be swivelled to set the balance into its vibratory arcs. The balance to be compared or vibrated is suspended by its hairspring attached to a scaffold and when the box is twisted on its platform both balances will start vibrating. Thus the suspended balance may be compared (in speed) with the master balance and its hairspring lengthened or shortened until both balances swing in unison

Waterproof

A vague term which has been challenged in the US Courts. Many watches used to be sold as being waterproof with vague descriptions of what "waterproof" meant. Many though were little more than splash-proof at best. This term should not now be used unless in connection with a warranted Divers' Watch or one designed with a sealed case and for prolonged submersion in water

Wax chuck

A cement chuck on which objects that cannot be held accurately in the split chuck are cemented to a brass rod held in this chuck

Winding pinion

The first winding wheel through which the stem enters. A wheel with two sets of teeth. One is set radial to its center and the other is set upright, crown style with ratchet teeth. The wheel above the clutch wheel

Wig wag

A small machine or tool to polish pinion leaves by a back-and-forth motion. Also called polishing shovels when used in conjunction with an eccentric pin set into the face of a tail-stock taper

Yoke

Part of the setting mechanism which holds down other setting parts. Also called the setting bridge and sometimes (incorrectly) meaning the clutch lever. A small metal piece holding down or straddling other (loose) parts