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Title: |
1868 Article-Brookbank, Charles H., Eagle Sawmill Head-Block |
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Source: |
Scientific American 02 Sep 1868 pg 152 |
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Insert Date: |
5/1/2012 8:55:43 PM |
Improvement In Sawmill Head-Blocks
The object of this improvement is to overcome the difficulty existing in other machines which will not allow the increasing or diminishing the thickness of boards lees than by eighths of inches, and at the same time work accurately, leaving the last board always perfectly even. With this device the thickness of the board can be regulated to the smallest fraction of an inch.
A represents a saw carriage and B the bases of the head-blocks. These may be of any suitable material or form. C is a four-threaded screw with inch and a-half pitch, two inches diameter. D is the standard or knee sliding on the Base, B, and having a nut on the under side engaging with the screw, C, and a set bolt to hold it steadily in place.
One revolution of the screw advances or recedes the knee one and a-half inches. E, on the front of the machine, is a horizontal bar to which is secured by set screws the two racks, n, the teeth of which mesh in pinions turning loosely on the screw shaft, C, the pinions having cast on them ratchets in which engage pawls pivoted to the balance wheels. An inside ratchet is keyed fast to the screw shaft, and is merely for the purpose of holding to its place the screw after it is set. The whole is operated by a hand bar or lover, as shown in the engraving, a full throw of the lever setting the heads for a one and a-half inches board, and a set screw regulating its throw for other thicknesses. The edges of the bases, B, are graduated to inches and their fractions, as a guide to the eye. The simplicity, accuracy, and durability of these head blocks have commended them to the proprietors of a number of the largest mills in the country, and they have never yet failed to give entire satisfaction. Patented through the Scientific American Patent Agency, Nov. 19, 1867, by Charles H. Brookbank, Connersville, Ind., whom address for machines and shop rights.
Patent # 70,950 |
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1868 Brookbank, Charles H., Eagle Sawmill Head-Block
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