This windmill was patented in 1912 and is one of the earliest oil bath windmills produced in the world. By the time ALSTON patented this model his company had already sold over 30,000 windmills and dominated the Australian market as well as exporting overseas.
There are two oil wells, one in the sealed nose section and one in the bottom of the main casting. It was designed as a heavy duty pumper and has only three moving parts with ball bearings used throughout, except for the roller thrust bearing in the nose. The drive was by a crank which operated within a guide casting attached directly to the pump rod. The pump rod entered the main engine casting at the base and exited at the top under a waterproof metal tube.
James ALSTON's intention with this design was to get an exactly centred stroke from the normally circular motion of a direct action crank plate and pin design. This he did successfully, and wear of the pump rod as it slides up and down through guides in the main casting, does not seem to have been a problem in the smaller mills.
From illustrations it appears that larger models, as shown in the drawing on this page, had some sort of replaceable packing arrangement. Some changes were made to the main casting through the years to allow for a greater depth of oil to be used. A curved brass fitting on the crank disc scooped oil up as the wheel rotated and ran it back onto the moving parts in the top section of the head. There are at least three variations in the crank roller guide, and other parts such as the tail buffer spring reflected general changes which ALSTON tended to make across the board to all of his mills.
This design was available at least up until 1941. The ALSTON GEARLESS mills were not a cheap windmill compared to others offered by ALSTON, but they seem to have been well supported by the buying public.
The ALSTON 'GEARLESS' was originally available in wind wheel sizes from 8 through 10, 12, 14, 16, 18 to 20 foot. Later a 22.5 foot model was added. All those sizes were still available in 1934/5 and general advertisements for the 'GEARLESS' windmill are recorded for December 1941. The largest 'GEARLESS' made had a 25 foot diameter wind wheel. This, James ALSTON states, had a choice of three strokes, but from existing information it is unclear how this was possible, unless this particular mill was provided with a choice of crank pin sites on the crank disc.