IMPROVEMENTS IN VALVES AND VALVE GEAR FOR MOTOR ENGINES WORKED BY STEAM AND OTHER ELASTIC FLUIDS."
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Henry Simon at the Office of the
Commissioners of Patents on the 21st October 1880. A communication
from abroad by Robert Kuechen, of Bielefeld, in the German Empire.
26
HENRY SIMON, of No. 7, St. Peters Square, Manchester, in the County of
Lancaster. IMPROVEMENTS IN VALVES AND VALVE GEAR FOR MOTOR ENGINES
WORKED BY STEAM AND OTHER ELASTIC FLUIDS." [A communication from abroad
by Robert Kuechen, of Bielefeld, in the German Empire].
This Invention has reference to an improved construction of expansion valve
gear for lift valves, whereby simplicity of construction is combined with great
strength, and whereby any desired degree of expansion may be obtained, the valves
being made to work with a constant lead with very small dead space, and to open
rapidly to full steam.
For this purpose the admission and exhaust valves are made to work each with
a double seat upon a cylindrical framing that forms the seating for both the valves,
the exhaust valve being situated immediately below the admission valve, the
former having its seats outside and the latter inside the framing. The rods to the
respective valves pass in opposite directions through the valve box, and have slots,
in each of which works the one end of a bell crank lever pivotted to brackets on the
valve box, or to any other suitable fixed point, the other end of each bell crank
lever being actuated by a revolving cam, arranged as follows:-The spindle of a
ball governor of any known construction drives by toothed bevil gear a spindle, on
which is fixed one of two discs that face each other with the free ends of the
beforementioned bell crank levers between them. The second disc is carried by a
tubular spindle surrounding the first named spindle, and carries a toothed segment
in gear with which is another toothed segment, that is turned backwards or
forwards by the governor slide through a greater or less angle according as the
slide rises or falls, whereby the hollow spindle and its disc are also turned
backwards or forwards to a greater or less degree. The first named disc that
revolves with its spindle carries a curved or cam shaped piece, one end of which is
pivotted to the disc, while the other end can move inwards or outwards within
certain limits against the face of the disc, according as it is acted upon by a spiral
cam fixed on the face of the second disc, such spiral cam being so arranged that as
the pivotted cam is carried round by its disc, the other cam bears with its outer
face against its inner face, and so causes it to move outwards more or less at a
certain point of its revolution. The free end of the bell crank lever that actuates
Povice 2.71

page_text: the admission valve, carries within a slot an adjustable block that bears against the
outer surface of the pivotted cam, which has a drop at each end, so that as it
rotates it actuates the lever so as to open the admission valve rapidly and keep it
open for a time, the duration of which is determined by the position of the spiral
cam actuated by the governor, that is to say, when the speed of the engine decreases
the governor slide moves the spiral cam so as to bring the pivotted cam into
position for keeping the admission valve open a greater length of time, and vice
versa.
The revolving disc also has a cam path, in which works a roller carried by the
end of the bell crank lever that actuates the exhaust valve, so that by the rotation
of such cam path the valve is opened and closed at the required time. If desired,
instead of working the expansion gear by means of a governor, the toothed segment
that actuates the tubular spindle with its disc and spiral cam can be worked by
hand.
It will be readily understood that where there are admission and exhaust valves
at each end of the working cylinder, both sets of valve gear are worked by one
and the same spindle, receiving motion from the governor by bevil gear at or
about the middle of its length.