The Shutters

The shutters fit between the sail frame openings, the Fulbourn Mill would require 184 shutters. Each shutter is connected to a push rod with a hinged bracket; the push rod is connected to the spider gearing infront of the cannister at the centre of the sails. The spider gear (photo bottom left) will push or pull a striker rod that goes through the middle of the windshaft to the rear of the cap. Here it is connected to a arc gear which is attached to a curved lever and is controlled be a chain hanging down to ground level in a loop (photo bottom right). If the wind is very strong the shutters will hinge back lifting the weight on the chain, when the wind eases the weight will close the shutters to catch the maximum wind power. The chain can be used manually to open and close the shutters; used when Mill is not in use. The majority of the shutters at Fulbourn are cloth covered frames, but originally a number were solid wood.