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Carlo Croce, Cogorno, Italy. 2000. 25"h x 15"w x 9"d. Custom design, completely hand made. Arnfield gravity escapement regulator with perpetual calendar work, moonphase and equation of time. The movement is fully jeweled up to the motion works, including impulse arm. Pendulum has an invar rod with with bi-metal bob. The complexity of this clock brings in the parts count at over 440.

The Arnfield gravity escapement was invented in 1986. This variant of the gravity escapement achieved the goal of a detached gravity escapement pendulum, see video below. In normal gravity escapements, the impulse is achieved without contact with the rest of the train, however the way a standard gravity escapement is designed as in the case of Lord Grimthorpes' double-three legged escapement, the unlocking is not detached, but is of small significance. (See an example of this escapement in the tower clock section). Grimthorpes' escapement is used in 'Big Ben', London, England and his real contribution to the development of the gravity escapement was the addition of the air brake. This device is located on the escape arbor and is attached by a friction clutch. The inertial action of this fan keeps the gravity arms from bouncing off the pallets; thus avoiding the tripping of the escapement that plagued earlier designs. For more information on the Arnfield gravity escapement see My Own Right Time, Philip Woodward, pp. 29-30.

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