Be it known that I, WILLIAM DUNN, of the city of Hamilton, County of Wentworth, Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements [sic] in Machines for Setting the Teeth of Saws, and more especially the teeth of band-saws,¹ and of which the following is a full, clear and exact description, reference being had to the accompanying drawings which form part of the same.

My invention consists first in constructing the clamping jaws along their faces with vertical recesses and an adjustable rest constructed with a series of projections or corrugations on each side adapted to fit between said jaws for the purpose of preventing the saw falling below the upper edge of the rest, or between it and either jaw when they are open and at the same time to allow the clamping jaws to come sufficiently close together to securely clamp the saw. The rest is capable of being raised or lowered by means of screws or other appliances to accomodate saws of various widths.

My invention consists, secondly, in a pair of levers connected together by a bar, each lever provided with an adjustable pean, operating in connection with an adjustable and removable plate on each side of the clamping jaws, said levers being adjustably pivoted at their ends at each side of the jaws to lugs provided with a series of holes, the holes allowing the pivot end of the levers to be elevated or depressed, as may be required.

My invention consists, thirdly, in lugs formed on both sides of the machine for the purpose of containing and pivoting the levers and these lugs are provided with a number of pivot-holes for the purpose of arranging the levers to assume any desired angle at the point of contact with the saw-teeth.

My invention consists, fourthly, in combining with the principal lever an arrangement of devices or mechanisms for moving the saw forward as the teeth are being set, the same consisting of a sliding plate reciprocating at right angles to the oscillation of the lever, constructed with a portion of its face inclined and a portion straight, and at its rear portion with a slot-connecting block, adjustably secured to the plate by set-screw, draw-hook pivoted to the connecting block and spring for retracting the parts, all constructed and arranged to operate as and for the purposes hereinafter more fully set forth and shown.

My invention consists, fifthly, in a novel, removable, independent support for that part of the saw extending beyond the clamps or jaws, composed of a screw-shank with movable clamping-collar, two vertical axes provided with anti-friction rollers and horizontal anti-friction roller, as and for the purposes hereinafter more fully described.

¹ Dunn had several patents, mostly improvements to devices already in use. Isaac McQuesten had helped sponsor some of Dunn's efforts to sell his patents to manufacturers for a profit, but Dunn was quite unsuccessful and offered to repay Isaac. See W2554a for more about Dunn.