US11365A - Mode of driving and straining saws - Google Patents

Description

UNITED STATES PATENT OFFICE.

JAMES FISHWICK AND JOHN FISHVICK, OF LEXINGTON, KENTUCKY.

MODE OF DRIVING AND STRAINING SAWS,

Speccaton of Letters Patent No. 11,365, dated July 25, 1854:.v

To alliwhom t may concern Be it known that we, JAMES FrsHwioK and JOHN Fisi-iwioir, of the city of Lexington, county of Fayette, and State of Kentucky, have `invented a new and useful lmprovement in the Application of Steam for the Purpose of Driving 'Saws and Keeping Them Sti-aimed; and we do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l, is a perspective view of a saw mill, having our invention applied. Fig-2, is a vertical section of the steam cylinders.

Similar letters of reference indicatecorresponding parts in both figures.

Our invention relates tothe direct driving of the saw by its attachment directly to a piston working in a steam cylinder, and

. to the strainingof the same without a gate,

by the action of steam upon two above and the other below. i

lt consists inthe employment of two cylinclers andpistons of unequal. size, the lower cylinder and Qpiston being of suitable area pistons, one

to drive the saw, and `only receiving the steam during the down stroke or cut, and the upper cylinder and `piston being always full of steam, but being only just of suilicient area to keep the saw properly strained, and to raise it., i

To enablethose skilledin the art to make and use our invention, we will proceed to describe its construction and operation.

A, is the framing of the `machine support-` ing the large lower cylinder, B, and the small upper cylinder, C, whose axes are both in line. The cylinder, B, is open at the bottom, but closed at the top `where the rod, D, of its piston, E, passes through a stufling boX, andis furnished with a-valve chest, F, like any other single acting steam cylinder, ittedwith a slide valve, G, which opens the port, a, leading tothe top of the cylinder, and brings it in communication with the eX- haust port, b. The valve chest is supplied with steam by a pipe, c. The upper cylinder, O, is open at `the top,but closed at the bottom, where` the rod, H, of its piston, I, passes through aistuiling boX, and it receives steam under the piston by means of a pipe, d, from the valve chest.

The saw, J, is connected to the upper piston rod by a cross head, K, working on guides, and to the lower piston rod by a cross head, L, which also works on guides, and which has a long straight slat at right angles `to the piston rod, to receive a sliding box, f,

in which works the crank pin,e, of a crank, M, on a shaft, N, which carries afly wheel, O, and an eccentric, P, to work the slide valve.

The piston, I, of the smaller cylinder, H,

being always exposed to the steam, serves the purpose of straining the saw while the steam acts upon the larger piston, and drives down the saw, but as soon as the steam is exhausted from the large cylinder, the small piston raises the saw and the large piston.

The advantages of `driving the saw, by

iconnecting it directly to the piston, `and of straining it without a gate by steam acting on pistons, are well known; but these two n features have never been combined so advantageously 'as in our invention, the principal advantages ofwhich are, that a large cylinder, full of steam, is only used to drive downthe saw, and make the cut, and a small one to raise it, thereby saving steam, and `that the same steam which drives the saw,

strains it.`

l/Ve do not claim the straining of saws by `steamfor other elastic fluid, neither do we keep the saw strained while cutting, and to raise it and thelarger piston, substantially as herein described.

` JAMES FISHWIOK. JOHN FISHWICK.

Vit-nesses 1 n JN0. S. HANsBRo, D. M. BARKLEY.

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