US700A - Photo-litho - Google Patents

Description

UNITED srArEs 4afirmar oinnoE.r

JNO. C. YAIES, 0F COLUMBIA, TENNESSEE.

SAWMILL WITHOUT SAW-GATE.

. Specification of Letters Patent No. 4700, dated April 21, 17838.

To all whom it may concern:

Be it known that I, JOHN C. YATEs, of Columbia, in the county of Maury and State of Tennessee, have invented a new and useful Improvement in the Construction of Sawmills, called Yates Gateless Sawmill, which is described as follows, reference being had to the annexed drawings of the same, making part of this specication.

The frame A, Figure l, may be made of any convenient form, size, and strength for the purpose intended. A vibrating beam B, Figs. 1 and 2, is placed at the top of the frame. Its fulcrum G, is triangular or polygonal, instead of round. It moves in rectangular boxes D, instead of curved. The sides of the fulcrum moving on the bottoms of the boxes may be made convex to prevent jarring, as the beam vibrates. To each end of the vibrating beam is attached a straight saw E, E, in the following manner, whose lower ends are attached to a crank shaft F, below. As the saws T heads,

rods, &c., at both ends of the vibrating beam are the same, only those at one end need be described. Then, to the end of the beam is attached in the usual manner by a joint a connecting rod G: to the lower end of this connecting rod a T head H: to the T head a harp-iron I with nuts J to raise or lower it z' to the harp iron the upper end of the saw E, the lower end of said saw being attached to another harp iron, or it may be attached immediately to a lower T head K, the last mentioned T head K being connected with the crank shaft by a pitman rod L.

The saw E is made to work vertically by means of rods M passing throu h the T heads over which rods they worr loosely, said rods being sustained in a vertical position by arms N projecting Vhorizontally from the main frame or in any convenient manner.

The nuts J on the ends of the harp iron are for straining the saws when they require it.

The other connecting rod, upper T head, harp iron, saw, lower T head, pitman, rod, &c., attached to the other end of the vibrating beam being made similar to those just described need not, therefore, be more particularly described.

. The crank shaft may be turned by pulleys and bands; or cog wheels, by steam; or

by water by means of a flutter wheel, 'or otherwise, applying the power directly to the crank shaft, or by the power of steam applied directly to the crank shaft.

There may be more than two saws, and

the saws may be arranged `in gangs, or

otherwise.

The operation of the machine Vis as follows: The crank shaft F being put in motion, one of the cranks will be up while the other is down, the pitman rod, saw, and connecting rod on one side draws down one end of the beam, at the same time raising the other end with the opposite saw, the

,beam vibrating on the triangular fulcrum. When one end of the beam is down it of course will rest on the corners of the ful-` crum nearest said vdepressed end of the beam, at the same time changing theV center by `raising it from the box and increasing the length of the other end of the beam, thus keeping the saws always strained to a proper degree of tension and 1so vice versa.

The object of having the fulcrum made in this shape is not only to change the center of vibration alternately by which the arms of the beam are alternately lengthened thus compensating for a loss experienced at every halfV revolution of the crank shaft by the extension ofthe pitman rods but also to prevent the saws or works being brokenfor when the cranks are horizontal the pitman rods form the hypothenuses of two triangles, which of course will produce longer lines than the perpendiculars` or the lines extending from the center of the joint or connection with the lower J head to the center of the crankshaft, and consequently produces a strain or drawing down at each end of the beam, simultaneously: and the plummer boxes being immovable and the center ofthe cylindrical fulcrum as of a steam engine for instance remaining unchanged. Of course the saws must either be broken or stretched, or some part ofthe connection be lengthened or injured. But the fulcrum being made of a triangular, or polygonal shape, with the lower side or that which moves over the bottom of the box fiat, or nearly so, the center of the vibrating beam is made to descend or approach nearer to the crank shaft at the moment the pitman Vrods are extended when the beam and cranks vceded from them in any of the most improved modes in use, known to mechanics;

but as no claim is made to this partei? the machine a particular description is notr deemed necessary.

What the subscriber claims as his inven- 2 i e voo tion and Which he desires to secure by Letters Patent eonsistsv In the form ofthe fulcrum of the vvibranting beam in Combination With the reetangw lar boxes in Whieh'it moves.

JOHN e. YATES.

Witnesses: y n,

WVM. l). ELLIOT, W. BISHOP.V

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