IMPROVEMENTS IN VALVE GEAR FOR MOTIVE-POWER ENGINES
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Alfred Vincent Newton at the
Office of the Commissioners of Patents, with his Petition, on the
21st December 1871.--A communication from abroad by Johann
Radinger, of Vienna, in the Empire of Austria.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN VALVE
GEAR FOR MOTIVE-POWER ENGINES," to be as follows:-
__
The chief object of this Invention is to provide steam engines that are
driven at high speeds with valve gear that will work easily, be little
liable to wear, and will admit of facile adjustment for the purpose of
making the cut-off at any desired portion of the stroke.
The Invention, which admits of some modifications, may be described
as consisting mainly of two concentric cylindrical valves working one
within the other, and rotating in opposite directions in a suitable valve
box in connection with the steam cylinder for the purpose of supplying
steam thereto and opening a passage for the exhaust, or if thought

page_text: steam from the cylinder.
desirable, additional valves may be used for the discharge of the exhaust
These concentric valves are jacketed to form
ways within them for the passage of the steam, and they are slotted
longitudinally to open these passages to the steam passages of the working
cylinder and to each other. The inner valve is mounted loosely on a
spindle which receives motion through bevilled gearing from the crank
shaft of the engine. This valve has a sleeve shaft continuation
extending upwards to near the top of the valve spindle, or to a level
with a centrifugal governor mounted on the spindle. A sliding collar
surrounding this sleeve shaft continuation is connected with the
governor by links, and it serves to carry a cross pin which passes
through the sleeve shaft and through the valve spindle. Straight
longitudinal slots are made in the sleeve shaft to receive this pin, and
there is also a helical or twisted slot cut through the spindle to receive
the pin, which pin acts as a key in that it holds the sleeve shaft and
spindle together, but it allows and indeed causes the sleeve shaft and
consequently the inner valve to receive an independent axial motion by
the movement of the pin along the helical or twisted slot, which
movement may be effected automatically by the action of the governor,
or by the attendant lifting the spindle through a lever acted upon by a
hand wheel and screw. This movement causes an alteration in the
relative position of the edges of the outer and inner valves, thereby
regulating the admission of steam to the cylinder.
To provide for the endway motion of the spindle (to produce this
result) it is connected by a feather to the bevil wheel which drives it.
The outer valve has also a tubular or sleeve extension to which is
fitted a bevil wheel that receives rotary motion from the crank shaft,
but in an opposite direction to the bevil wheel of the spindle. Thus
the two concentric valves rotate in opposite directions, and they will be
required to make each half a revolution for every stroke of the piston.
The steam as it is supplied to the engine first passes through coinciding
slots in the sides of the two valves to an annular space in the inner
valve, and then from that space through other coinciding slots to the
inlet port of the steam cylinder. As both the valves are rotating in
opposite directions while this takes place the cut-off will be sudden,
and thus no wire drawing of the steam will occur. Moreover as the
inner valve admits of adjustment, the cut-off may be retarded or

page_text: advanced as circumstances may require. The exhaust steam will enter
between the walls of the outer valve, and escape by the open ends
thereof. When independent exhaust valves are used, the walls of this
outer valve will not require to be made hollow.
advanced as circumstances may require. The exhaust steam will enter
between the walls of the outer valve, and escape by the open ends
thereof. When independent exhaust valves are used, the walls of this
outer valve will not require to be made hollow.
To facilitate fitting and to provide for wear, these concentric valves