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.
The Ireland, Chase and Lane were the best of all the shingle mills being built from the 1890's to the 1920's. This could be called the 'Golden Era of Shingle Mills.' It was during these years that the shingle mill enjoyed its greatest popularity and became a simple, efficient machine, and after this period, began decline in both popularity and advancement. Shingle mills still exist which are known to have been built in the 1850's and 1860's, but I doubt if any were made earlier than that, because the circular saw did not become popular until the 1830's, and even then it was very crude and inefficient. Almost all the blades were made the same as the sawmill blade. They were of a very thin gauge, and were attached to a tapered plate which was about half the diameter of the blade. This plate came to practically a knife edge around the outside, and its center varied from a half-inch to several inches. This plate performed three very important functions.
First, it strengthened the thin blade, and helped to keep it sawing with the grain and from sawing around knots. Second, it acted as a flywheel, keeping up the momentum of the saw as it cut through the block, allowing faster feeds to be used, and to be run with less horsepower. Third, as the shingle was sawn, the plate separated or spread it from the block and saw, preventing any binding or pinching which may otherwise occur.
The blades for shingle mills were usually about nine gauge and ranged from 24' to 42' in diameter.
Also accompanying most shingle mills was an edger. This was nothing more than a rotating iron plate with about five knives fastened to it, and on a slight skew to the radius of the plate.
In front of the plate was a narrow table that the shingle was set on. With the shingle resting on this table, it was fed by hand into the rotating knives, which quickly trimmed off all bark and squared the shingle.
I hope this will be of help to GEM readers and if it is favorably accepted, I have a lot more information on sawmills and Orog saws that I can submit later.