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1892 article on 60" band resaw |
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Manufacturer and builder / Volume 24, Issue 9; September 1892 |
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1/5/2015 8:32:03 PM |
Article text:
A NEW RE-SAWING BAND-SAW MACHINE.
The machine herewith illustrated will use saws as thin as 24 gauge and up to 6 inches wide, and, according to the maker's claim, will saw 16,000 to 20,000 feet per day, making a kerf of only 1/20 of an inch, or less, where most re-saws make 3/32 to 1/8, and more. The feeding is effected by four strongly-geared live rolls, while two smaller idle rolls guide the last end of the stock up to the finish cut. Strong springs hold the rolls upon one side up to their work, and enable them to yield to all inequalities of thickness or shape, while the rolls upon the other side form a guide in true line with the saw, thus insuring a cut parallel with one side of the stock. A friction device, controlled by a single lever, enables the feed to be instantly stopped and started, or to be run at any speed desired, without changing belts.
With machines employing step pulleys or gears for changing the feed, one speed may be just a little too much and the next one not near enough, resulting in decreased output.
The saw runs between hardened steel plates, filled with dogwood plugs, with the end grain in contact with the saw, and each plate can be
accurately adjusted by a single screw. The back of the saw has a bearing 1 1/2 inches long on the beveled edge of a conical roller of a special composition, harder than steel. What little wear does occur takes place across the full width of the beveled surface, and therefore does not form grooves, as would be the case with a plain roller. The upper guide is counterbalanced, and is adjustable, vertically, by a hand- wheel. This hand-wheel, the lever for controlling the feed, the hand- wheel for setting the feed rolls, and the scale showing to what thickness they are set, are all accessible from the sawyer?s working position. The upper wheel has a rim of bent ash, with steel spokes, and the lower one is a heavy iron casting. The lower wheel being thus much the heavier, acts as a fly-wheel to prevent sudden and violent fluctuations of speed, as in starting and stopping, and thus prevents the over-running of the upper wheel, which, being lighter, is capable of following the motion of the lower one without causing the saw to slip or to become slack on the working side. The rims of both wheels overhang the ends of the bearings, which latter are self-oiling. The overhanging feature effects the same result that some makers attain by the use of a clumsy and complicated arrangement of outside bearings.
The upper shaft can be angled while in motion. An adjustable spring maintains a proper tension on the saw and renders it much more secure against breakage than the weights commonly used for this purpose, as the inertia of weights prevents them from yielding quickly enough when a chip gets between the saw and the wheel, the result being a broken saw. To provide doubly against such an accident, a wood- en block is fitted in the throat between the saw and the wheel, so as to catch all chips and sawdust and discharge them beyond the rim. The lower wheel is kept from accumulations of sawdust by a scraper, and the upper one by a brush.
The body is a box-shaped casting in one piece, very strong and rigid, and it can be placed on any good floor without a special foundation.
The loose pulley is self-oiling, one inch smaller in diameter than the tight pulley, to slacken the belt when the machine is stopped, and it is provided with a step at the inner edge to cause the belt to shift easily.
Height of machine, 10 feet 7 inches; width, 7 feet 5 inches; depth, 6 1/2 feet; weight, complete, 7,000 pounds; diameter of wheels, 60 inches; driving pulley, 22 to 30 inches diameter, as ordered for an 8 inch belt; speed, 450 to 523 turns per minute, according to kind and width of lumber; thickness taken be- tween feed rolls, 21 inches, 12 inches on one side of the saw and 9 inches on the other; height of stock that can be sawed off, 30 inches.
The manufacturer is P. Pryibil, 521-533 West Forty-first street, New York, from whom additional information may be had on application. |
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