United States Patent Office.

Be it known that I, ELON A. MARSh, of Battle Creek, in the
county of Calhoun and State of Michigan, have invented a new and
useful Improvement in Steam-Engine Valve-Gear, of which the
following is a specification.

My invention relates to certain improvements in reversing – gear
for steam-engines; and it consists in the combination, with the
main shaft of the engine and the valve-rod, of two intermeshing
gear-wheels of equal diameter, one mounted on the main shaft and
the other upon a lever fulerumed to the main shaft and connecting
with the valve-rod by a wristpin in such manner that the
last-mentioned wheel may be thrown to either side of a line on the
plane of the reciprocation of the valve and the center of the main
driving-shaft, and thus change the motion of the valve and
engine.

In the accompanying drawings, Figure 1 represents a side
elevation of a portion of an engine, showing my improved
reversing-gear; and Fig. 2, a detached view of the reversing
lever.

The letter A indicates the bed of the engine, B the
pillow-block, and C the main driving-shaft, which may be of the
ordinary description.

The letter D indicates a lever, having a bearing, e, by which it
may be fulerumed to the driving-shaft near one end, and a similar
bearing, f, for the journal of the toothed gearwheel G. The said
wheel, when the parts are in place, intermeshes with a wheel, J,
equal in diameter and similar in all respects to the wheel G, the
said wheel J being rigidly secured to the driving-shaft C, so as to
rotate with it and impart motion to the wheel G.

The letter g indicates a wrist-pin secured to the wheel G, to
which one end of the valve-rod H is pivoted.

The free end of the lever D is provided with a handle, d, and a
spring-pawl, L, which is adapted to engage the detents m1 m2 in the
edge of a quadrant, P. The letter M indicates the fly-wheel of the
engine, a portion being broken away to show the intermeshing
gears.

The operation of my invention is as follows: When the parts are
in the position or with the lever on the line a a the wheel G will
be above a horizontal line drawn through the center of the
driving-shaft and the plane of reciprocation of the slide-valve,
causing the valve to move in one direction. To reverse the engine,
it is evident that it is only necessary to alter the position of
the lever so as to bring it on. the line b b, carrying the wheel
below the plane of reciprocation of the valve and the center of the
shaft C, and thus changing the motion of the valve.

Having thus fully described my invention, what I claim, and
desire to secure by Letters Patent, is

In combination with the main driving-shaft of an engine and the
valve-rod thereof, the inter gearing cog-wheels of equal diameter,
one fixed on the driving-shaft and the other capable of a movement
partially around the first mentioned, the latter having a
wrist-pin, to which the valve-rod of the engine is connected,
whereby said valve rod is adapted to reciprocate the valve and
operate the same to reverse the engine, substantially as
specified.

ELON A. MARSH, Witnesses: E. B. Smith, W. G. MOREHOUSE.

The letter on the Marsh Valve Gear Patent. It is the courtesy of
Vic Winter mantel of Box 4200, Bellevue, Pennsylvania, and he gives
credit to Mr. Arthur Bisek for getting this copy for him. It is an
interesting document and you will want to keep it for historical
reasons.