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Title: |
1882 Article-F. J. L. Blandy, Double Circular Sawmill |
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Source: |
American Machinist, 28 Oct 1882, pg. 5 |
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Insert Date: |
3/18/2015 9:20:53 PM |
Improved Double Circular Saw-Mill.
The double circular saw-mill here represented carries two saw mandrels, one placed above the other, as shown in the engraving. The saw collars are forged solid upon these mandrels, and after being turned, the mandrels are finished upon their bearings to insure perfect accuracy. The collars upon the mandrels are recessed, to cover the ends of the boxes, thus preventing the leakage of oil or the admission of grit and dirt. The boxes are sell-adjusting, being pivoted in such a way that a perfect alignment is always insured. The upper mill being made entirely of iron is detachable, and can at any time be attached to a single mill. The mandrel passes through a single casting with journal boxes at each end. The box at the saw end is pivoted to the frame, while the box at the other end, having a lateral movement, is controlled by a screw. This arrangement allows the lead of the saw to be changed, which insures perfect alignment in the two saws. The pulleys are turned both inside and out, thus securing a perfect balance of rotating parts when running at high speeds. The carriage being shod with iron prevents excessive wear and facilitates the shifting of head blocks.
Ways are of heavy wood, being heavily ironed both sides. The feed of the carriage consists of a small friction paper-wheel in contact with the face of a turned iron pulley. These pulleys are on independent feed shafts, and not on either of the saw arbors. The direction of the feed is controlled by one lever, and may be made to move the carriage either forward or backward, or it may remain at rest wherever desired. The feed may be varied by shifting a belt upon cone pulleys having four steps each. The axles of the carriage are of wrought iron, the length of which is the full width of carriage. The axles are fastened in the wheels, and have turned journals running in Babbitted, cast iron boxes. The large wheels at each end of these shafts have turned faces. The iron rack has large teeth and is of unusual strength. Set works arc composed of simultaneous detachable lever head blocks, with pawl lifters. It is well understood that upon the efficient operation of this mechanism depends the evenness and smoothness of the work produced. By using a device known as a pawl lifter, one lever only is used, whereas by some other systems more levers, with extra attachments, are used. By the use of one lever the sawyer can, without moving from his position, engage or disengage the pawls controlling the movements of one or both head-blocks, as may be desired. The teeth of the ratchets and gear wheels, as well as the rack of the head-block knees, are all cut in machines for that purpose. With cut gears and proper graduations, the thickness of lumber can be accurately regulated. The log can be moved distances varying from one-eighth of an inch to three inches, as required, by one throw of the lever.
These saw-mills are made by F. J. L. Blandy, Zanesville, O. |
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1882 F. J. L. Blandy, Double Circular Sawmill
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