The cap consists of a framework of wooden ribs supporting a metal covering. Originally this covering was of lead, but now it is made of aluminium. The cap and the sails have to be rotated into the wind by a hand-operated winch before the mill can work. Between the cap and the top of the wall is a system of rollers running in a channel or track plate.
The windshaft is the main axle on which the sails and brakewheel are carried. It is made of oak, about 22 feet in length and with a section up to 24 inches square. The windshaft weighs about two tons. The brakewheel transfers power from the sails to all the internal machinery. It also carries the brake to stop the mill. This eight-foot diameter wheel is made of oak and has sixty cogs of hornbeam. It weighs about one ton.
The wallower converts the vertical movement of the sails into the horizontal movement needed to drive the millstones. This particular wallower is of an early design known as a lantern pinion. This design is rare in England, but common in continental windmills.
The great spurwheel transfers power to the millstones. It drives the stone nuts which are located below each pair of millstones. The stone nuts turn the upper millstones. They are made of iron and each is attached to an iron spindle which passes through the centre of each pair of millstones.
The hurst frame supports the millstones and the machinery which supplies their power. This is an unusual arrangement in a windmill. Normally the millstones were positioned on one floor with the drive mechanism on the floor below.
Each pair of millstones consists of a fixed lower and rotating upper stone. They are enclosed by a wooden casing which supports a hopper above the stones. The hopper contains the grain, which is fed to the stones by means of a spout or shoe.
To ensure the grain flows evenly into the stones, the angle of the shoe may be altered by means of a cord attached to a twist peg.
The sack hoist brings bags of grain up into the mill from ground level. It takes its power from the vertical main shaft. A chain goes from the hoist up to a pulley on the floor above and then back down through the sack traps to the ground. |