HOW DOES A SHINGLE MILL WORK?
September/October 1978
Larry B. Schdknecht
5408 Genessee Street, Lancaster, New York 14086
In the March-April 1978 of GEM, J. M. Huckabee asked 'How
does a shingle mill work?' I hope this short article may help
him, and others who often wonder the same question.
Before I go into the details of these mills, it should be
remembered that just like gas engines and tractors, no two
companies build shingle mills the same. Each company came up with
their own novel ideas which were supposed to be better than their
competition. The exception to this rule is the Chase Turbine Mfg.
Company, and the Lane Mfg. Company whose shingle mills were about
identical.
There are chiefly two different types of shingle mills, the
'Vertical' and the 'horizontal.' This refers to the
position of the blade. Often the 'horizontals' are also
called 'merry-go-round' shingle mills. The mills made by
Chase Turbine Mfg. Company, American Sawmill Machinery Company and
DeLoach are good examples of this kind. Good examples of the
'vertical' kind are the ones made by the Lyon iron Works
known as the 'Ireland', Chase Turbine Mfg. Company, Lane
Mfg. Company, and the Trevor Company.
The blocks of wood (bolts) to be sawn were held as a carriage
which fed them into the saw. The saw always cut with the grain, of
course, but the blocks were either held sideways and cut through
the length, or the block was held endways and the saw cut through
the ends from one to the other.
The carriages were either fed into the saw by hand, by the use
of a rock and pinion, or a crank or bull gear and a connecting rod.
I believe the type using the crank and connecting rod was the most
common. A good example of this type of feed is found on the Ireland
mill built by the Lyon Iron Works. All shingle mills except the
hand feed, used simple friction clutches to engage and disengage
the carriage feed.
The block feed on the carriage is quite a simple affair in
principle, but is often complicated by many parts. The dogs which
hold the blocks are toothed wheels mounted on a rotating shaft. By
the use of a rotating eccentric and a tapered wedge, first the top
dogs rotate more than the bottom ones, to put the taper in that
shingle, then as the carriage returns, the eccentric is turned 180
degrees and the bottom dogs rotate more than the top ones, thus
adjusting for the taper of the next shingle. This is how the
Ireland mill operates. Many of the 'horizontal' mills
simply had a pair of knives with teeth on them which closed, on the
ends of the blocks, griping it like fingers. After each shingle was
cut, these knives or dogs would be opened, allowing the block to be
dropped to a pre-set stop plate, which would set it up with the
right taper for the next cut. The only ''vertical'
shingle mill using this type of dogging is the Trevor made in
Lockport, New York. Of course, there may be many others which I
don't know about.