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10.Trip

Tren

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7. Hand. Frame Spring & hand

H

it.

These are then taken off, and another tier cut in the same manner, that is, when the log is large enough to admit of two tiers.

References to the Plate.

Fig. 1. gives a top view of the machine with the log in it ready for working.

2. gives a side view of the same.

3. an end view of the same with a log as partly cut.

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Reference to the several Parts as put together.

AA. The Frame, which is made of timber about 8 by 14 inches and put together by screws.

BB. The Carriage, made of timber about 7 by 8 inches, put together by screws.

C. The Log as dogged and put into the machine.

D. Saw and Sappers.

E. Main Pulley and Shaft.

F. Feed Pulley and Shifting gear, which is connected to the rack, under the carriage.

G. Tightening Pulleys.

HH. Regulating Pulleys and Shaft.

I. I.

J.

Friction Rollers and Stands.

Index.

K. Index, Shaft and Dog.

L. Centre iron and Dog.

MM. Iron Slides bolted to the sides of the frame for the trucks to travel upon.

NN. Revolving Lever and Springs.

O. Pin, which attaches the Lever to the sides of the frame, and is the Fulcrum on which it works.

P. Knob on the side of the carriage, that works the shifting lever. Q. Hand-frame, Spring and Hand.

R. Shifting Iron and Long Pointer.

S. Setting iron, which is bolted to the under side of the Carriage, and strikes the acute angle of the Shifting iron, when the carriage returns to set.

T. Trip Iron, which unlocks the hand from the Index, when the carriage returns to set.

UU. Stirrup Screws.

Remarks, &c.

This machine furnishes a new method of manufacturing lumber for various useful purposes. Though the circular saw had previously been in operation in this country, and in Europe, for cutting small stuff, it had not, within the know]edge of the writer, been successfully applied to solids of great depth; to effect which, the use of section teeth are almost indispensable.

In my first attempts to employ the circular saw for the purpose of manufacturing clapboards, I used one nearly full of teeth, for cutting five or six inches in depth into fine logs. The operation required a degree of power almost impossible to be obtained with the use of the band; the heat caused the plate to expand, and the saw to warp, or, as it is termed, to get out of true. To obviate these difficulties, I had recourse to the use of section teeth, and the experiment completely succeeded. The power required to perform a given quantity of work by the other method, was, by this, diminished at least three quarters. The work, formerly performed by 70 or 80 teeth, was by the last method performed by 8 teeth ; the saw dust, which before had been reduced to the fineness of meal, was coarser, but the surface of the lumber much smoother, than when cut with the full teethed saw.

The teeth are made in the form of a hawk's bill, and cut the log up, or from the circumference to the centre. The saw may be carried by an eight inch band, when driven a proper speed, (which is from ten to twelve hundred times per minute,) will cut nine or ten inches in depth into the hardest white oak timber with the greatest ease. The sappers at the same time cut off from one to two inches of the sap, and straighten the thick edges of the lumber.

The facility with which this saw will cut into such hard materials, may be supposed to result from the well established principle, that where two substances in motion come in contact, their respective action on each other is in direct proportion to their respective velocities; thus, a circular plate of iron, put into a quick rotary motion, will with great ease penetrate hardened steel, or cut off a file, when applied to its circumference; and the same principle is applicable to a rotary saw for cutting wood. The requisite degree of velocity is obtained by the continuous motion of the circular saw; by which also it has greatly the advantage of one that has but a slow motion on account of dulling, as the teeth are but little affected, and being only eight in number, but a few moments labor is required to sharpen them. If the velocity of

the saw were slackened to a speed of but 40 or 50 times per minute, it would require at least four such bands to carry it through a log as above described.

One machine will cut from 18 to 20 hundred square feet of pine lumber per day, and two of them may be driven by a common tub wheel 7 or 8 feet in diameter, having 6 or 7 feet head of water, with a cog wheel, and trundle head so highly geared, as to give a quick motion to the drums, which should be about four feet in diameter. The machine is so constructed, as to manufacture lumber from 4 to 10 feet in length, and from two to ten inches in width, and of any required thick

ness.

It has been introduced into most of the New-England states, and has given perfect satisfaction. The superiority of the lumber has for three years past been sufficiently proved in this town, (Brunswick, Me.) where there have been annually erected from fifteen to twenty wooden buildings, and for covering the walls of which, this kind has been almost universally used. The principal cause of its superiority to mill sawed lumber, is in the manner in which it is manufactured, viz. in being cut towards the centre of the log, like the radii of a circle; this leaves the lumber feather edged in the exact shape in which it should be, to set close on a building, and is the only way of the grain, in which weather boards of any kind can be manufactured to withstand the influence of the weather, without shrinking, swelling, or warping off the building. Staves and heading, also, must be rived in the same way of the grain in order to pass inspection. The mill sawed lumber, which, I believe, is now universally used in the middle and southern states, and in the West-Indies, for covering the walls of wooden buildings, is partly cut in a wrong direction of the grain, which is the cause of its cracking and warping off, and of the early decay of the buildings by the admission of moisture. That such is the operation, may be inferred by examining a stick of timber which has been exposed to the weather: the cracks, caused by its shrinking, all tend towards the heart or centre, which proves that the shrinking is directly the other way of the grain. It follows, that lumber cut through or across the cracks would not stand the weather in a sound state in any degree to be compared with that which is cut in the same direction with them. have no hesitation in stating, that one half the quantity of lumber, manufactured in this way, will cover and keep tight and sound the same number of buildings for an hundred years, that is now used and consumed in fifty years. Add to

I

Remarks, &c.

This machine furnishes a new method of manufacturing lumber for various useful purposes. Though the circular saw had previously been in operation in this country, and in Europe, for cutting small stuff, it had not, within the knowledge of the writer, been successfully applied to solids of great depth; to effect which, the use of section teeth are almost indispensable.

In my first attempts to employ the circular saw for the purpose of manufacturing clapboards, I used one nearly full of teeth, for cutting five or six inches in depth into fine logs. The operation required a degree of power almost impossible to be obtained with the use of the band; the heat caused the plate to expand, and the saw to warp, or, as it is termed, to get out of true. To obviate these difficulties, I had recourse to the use of section teeth, and the experiment completely succeeded. The power required to perform a given quantity of work by the other method, was, by this, diminished at least three quarters. The work, formerly performed by 70 or 80 teeth, was by the last method performed by 8 teeth; the saw dust, which before had been reduced to the fineness of meal, was coarser, but the surface of the lumber much smoother, than when cut with the full teethed saw.

The teeth are made in the form of a hawk's bill, and cut the log up, or from the circumference to the centre. The saw may be carried by an eight inch band, when driven a proper speed, (which is from ten to twelve hundred times per minute,) will cut nine or ten inches in depth into the hardest white oak timber with the greatest ease. The sappers at the same time cut off from one to two inches of the sap, and straighten the thick edges of the lumber.

The facility with which this saw will cut into such hard materials, may be supposed to result from the well established principle, that where two substances in motion come in contact, their respective action on each other is in direct proportion to their respective velocities; thus, a circular plate of iron, put into a quick rotary motion, will with great ease penetrate hardened steel, or cut off a file, when applied to its circumference; and the same principle is applicable to a rotary saw for cutting wood. The requisite degree of velocity is obtained by the continuous motion of the circular saw; by which also it has greatly the advantage of one that has but a slow motion on account of dulling, as the teeth are but little affected, and being only eight in number, but a few moments labor is required to sharpen them. If the velocity of

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