COQUERET. A steel end-plate. After about 1735, a coqueret is found on French watches to give a bearing for
the top balance staff pivot. It is screwed to the balance cock. By 1770 it was in general use on the continent for
better quality watches until the introduction of jewelling from England. The underside was highly polished to give
a good bearing for the pivot
COUNT WHEEL. A wheel in the striking train that controls the number of hours struck. It consists of a series of eleven notches cut on the periphery of the wheel at increasing distances between each corresponding to the hours struck. A detent or L-shaped lever rides over the raised portions and drops into the slots as the count wheel revolves, which it is allowed to do at each hour when the detent is raised. The striking train is free to run when the detent is lifted, and the watch strikes for as long as the detent is held raised by the projections. There is no projection for 1 o'clock since the detent is merely lifted for a sufficient interval for one blow to be struck, and dropped again. Similarly, if half-hours are struck, the notches are sufficiently long to allow the detent to lift once and drop again before the next projection isreached. The system, though simple, has the disadvantage that the hours are struck in regular progression without reference to the positions of the hour hand.
The alternative name for the count wheel is 'locking plate'. 'Rack-striking' superseded it.
COUNTERPOISE-PALLETS. In some high-quality Swiss levers of the 19th century a counterpoise to balance the pallets and fork was provided, the pallet arms, fork and counterpoise being filed out of one piece and highly polished.
CRANK LEVER ESCAPEMENT. A detached escapement sometimes referred to as the 'crank roller', or more recently as 'Massey's escapement'. This escapement, as designed by Edward Massey in 1814, would appear to have been derived from the Lither-land rack lever (q.v.). The rack has disappeared and substituted for the pinion is a roller mounted on the staff and having an impulse pin resembling a single leaf of a pinion; this projects from the circumference of the roller. The impulse pin acts in a square notch cut in the end of the lever, the notch being at right angles to the pallets. Two fork-like prongs extend either side of the notch and these provide the safety action, preventing the lever getting out of engagement until either of them enter slots cut on each side of the impulse pin. Shortly after 1815, the acting surface of the impulse pin became a jewel - i.e. a jewel held between upper and lower sections of the 'pinion leaf'. A little later, a further change resulted in the pin itself becoming a jewel.
There are thus three stages of the crank lever. In the original form, draw seems to be absent, but in the later variants it was introduced. The crank lever led in due course to the single table roller (q.v.). Edward Massey died in 1852 and is buried in St John's, Islington. He also invented a form of keyless winding. A true cranked roller - i.e. where the roller is a separate entity to the balance staff - was used by Emery, the roller being pivoted, before 1800.
CRANK ROLLER. See CRANK LEVER ESCAPEMENT.
CROWN-WHEEL ESCAPEMENT. Another name for the verge escapement (q.v.). The name derives from the form of the escape wheel which somewhat resembles a medieval crown.
CRESCENT. The crescent-shaped hollow cut out of the roller in a lever escapement to permit the guard pin or dart to pass.
CURB COMPENSATION. See COMPENSATION CURB.
CURB - PINS. Two pins which embrace the balance spring at its outer end near to its attachment. The pins are fixed to the regulator or index; 'index-pins' is an alternative term. The time of vibration of a balance is adjusted by altering the position of the pins. If the pins are moved towards the outer attachment point, the effective length of the spring is increased and the watch is made to lose; if the regulator (and therefore the curb-pins) is moved the opposite way, the reverse takes place. A similar effect to lengthening the spring is achieved by increasing the distance between the curb pins. See Fig. III.
CUT BIMETALLIC BALANCE. See BALANCE.
CUVETTE. An inside cover to protect the movement, hinged and sprung, often of brass even in good quality gold continental watches. The cuvette is sometimes provided with holes for the winding and set-hand squares, and is frequently, engraved with the maker's name and movement number and often with the type of escapement and the number of jewels embodied in the movement.