Henry Haering, New York city.--This is an improved device for
operating the slide valve of a steam engine from the piston rod of
said engine, in such a way that the valve will be moved slightly to
partially uncover the inlet and exhaust ports as the piston completes
its stroke, and its motion will be continued in the same direction as
the piston begins to move upon the return stroke, until the ports are
fully opened, and will then stand still, with the ports fully open,
until the piston has nearly completed its return stroke. It consists
in the combination of a three-armed bar, two levers, connecting bar,
and connecting lever, with the piston rod and the valve stem of
a steam engine; and in the combination of a lockbar, spring, two
cylinders, and pin, with the two levers and the three-armed bar.
As the piston approaches the end of its stroke, the upper end of an
upright arm of a bar strikes the concaved side of the upper part of
one of the levers operating it, and moving the slide valve to close
the ports and admit steam in front of the piston. As the piston begins
its return stroke the inclined upper surface of one of the side arms
of the three-armed bar comes in contact with the lower end of the said
lever, and continues its motion in the same direction, fully opening
the said inlet port, which remains fully open until the piston has
again nearly completed its stroke.