IMPROVEMENTS IN OR APPLICABLE TO STEAM AND AIR ENGINES."
Year: 1881

page_text: LETTERS PATENT to George Sellers, of Birstall, in the County of York,
Engineer, for an Invention of "IMPROVEMENTS IN OR APPLICABLE TO STEAM
AND AIR ENGINES."
PROVISIONAL SPECIFICATION left by the said George Sellers at the Office
of the Commissioners of Patents on the 17th February 1881.
GEORGE SELLERS, of Birstall, in the County of York, Engineer. "IMPROVEMENTS
IN OR APPLICABLE TO STEAM AND AIR ENGINES.
This Invention relates,-
Firstly. To the expansion gear or automatic cut off apparatus employed in steam
or air engines, for the purpose of closing the passages for the inlet of steam or air
into the cylinders of steam or air engines at earlier or later periods in the stroke
of the piston as and when required. For this purpose when applied to a beam
engine 1 attach a suitably shaped fixing to the side of the steam chest or other
suitable place, and connect thereto a bell crank or other lever, one end of which is
connected to the cut off valve spindle, and the other end connected to the upright
rod of a vacuum cylinder, or weight or spring may be employed, for instantaneously
dropping the bell crank lever after it has been lifted by another upright rod, the
upper end of which is connected to the said bell crank lever, and its lower end
connected to and operated by a series of levers and rods from the "governors." On
the bottom of the latter mentioned upright rod is a suitably shaped socket, having
a ball therein resting or bearing upon a cam attached to or forming part of a
revolving circular or other shaped plate, employed for the purpose of raising one
end of the bell crank lever, and so regulating the position of the cut off valves.
Secondly. The Invention relates to the means or method of mounting the
expansion valve or cut off valve working on the back of the main slide valve. This
I accomplish by inserting the cut off valve within V grooves formed on the slide valve,
and in attaching a bracket or saddle to the cut off valve, extending across the face

page_text: thereof, and connected by nuts or other means to the cut off valve spindle, which
actuates the same.
The saddle is extended at right angles for receiving anti-friction pullies which
embrace the cut.off valve for the purpose of reducing friction. -
By these means the cut off valve is kept in proper position with the slide valve,
and is effectually prevented from getting disarranged or twisted sideways.
Thirdly. To the means of expanding or forcing the metallic packing rings of the
piston against the inside of the cylinder, and this I accomplish by means of a coiled
spring (after the manner of an air spring), which is placed within the piston, one
-end being secured to a stud, and the other end loose, by which means the pressure
of the spring will force the metallic packing-rings against the inside of the
cylinder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Sellers in the Great Scal Patent Office on the 17th
August 1881.
George SELLERS, of Birstall, in the County of York, Engineer. “IMPROVEMENTS
IN OR APPLICABLE TO STEAM AND AIR ENGINES."
This Invention relates,-
Firstly. To the expansion gear or automatic cut off apparatus employed in steam
or air engines, for the purpose of closing the passages for the inlet of steam or air
into the cylinders of steam or air engines at earlier or later periods in the stroke
of the piston as and when required. For this purpose, when applied to a beam
engine, I attach a suitably shaped fixing to the side of the steam chest or other
suitable place, and connect thereto a bell crank or other lever, one end of which is
connected to the cut off valve spindle, and the other end connected to the upright
rod of a vacuum cylinder, or weight or spring may be employed, for instantaneously
dropping the bell crank lever after it as been lifted by another upright rod, the
upper end of which is connected to the bell crank lever, and its lower end con-
nected to and operated by a series of levers and rods from the "governors." On
the bottom of the latter mentioned upright rod is a suitably shaped socket, having
one or more balls therein resting or bearing upon a cam attached to or forming part,
of a revolving circular or other shaped plate, employed for the purpose of raising
one end of the bell crank lever, and so regulating the position of the cut off valves.
In order that these improvements may be better understood, I herein give
reference to the accompanying Sheets of Drawings, wherein Fig. 1 shews the first
part of my Invention applied to a McNaught beam engine. A represents the steam
chest, to which is bolted the fixing B for supporting the various parts. C is a ram
connected to the cut off valve spindle D by adjusting thread and nut, the other end
of the said ram being connected to a bell crank lever E, such bell crank lever being
connected to the upright rod F, working in a vacuum cylinder G for "dropping" or
allowing the bell crank lever to instantaneously lower when it is set at liberty.
H is a revolving disc having a cam formed on its upper surface, shewn more clearly
in Figs. 2 and 3, employed for the purpose of actuating in one direction the cut off
valve rod D, which is accomplished by raising the rod I attached to the bell crank
lever E. On the bottom of this rod I is an anti-friction ball or balls, revolving
within a suitably shaped socket J, which lessens the friction and allows the free
movement of the ball upon the surface of the cam. It will thus be seen that the
point of expansion or "cut off" is altered from time to time by the varying speed
of the governors K, which operates the rod L, sliding or pushing the anti-friction
ball backward and forward upon the cam, and so controling and regulating the
cut off valve spindle; and consequently opening and closing the passage for the
inlet of steam or air into the cylinders. In Figs. 4 and 5 I have shewn the appli-
cation of my Invention to engines fitted with rotary steam and exhaust valves,
both working in one cylindrical chamber, and fitted with steam inlet and outlet
ports, as shewn fully in section of cylinder, Fig. 5, in which a are the cut off valves,
b the exhaust valves, c the steam inlet, and d the exhaust or outlet. In Fig. 4 I
have shewn full elevation of cylinder governing apparatus, including the cams H,
which are connected to cut off valves by rods M and lever N, a spring P being
employed to keep the bowl on the rod M up to the face of the cam.
Secondly. The Invention relates to the means or method of mounting the
expansion valve or cut off valve working on the back face of the main slide valve.
This I accomplish by inserting the cut off valve within V grooves formed on the
slide valve, and in attaching a bracket or saddle to the cut off valve, extending

page_text: across the face thereof and connected by nuts or other means to the cut off valve
spindle which actuates the same. The saddle is extended at right angles for
receiving anti-friction pullies, which embrace the cut off valve for the purpose of
reducing friction. By these means the cut off valve is kept in proper position with
the slide valve, and is effectually prevented from getting disarranged or twisted
sideways.
This part of my Invention is illustrated in Figs. 6, 7, and 8, in which I have
shewn plan, cross section, and longitudinal section of a slide valve and expansion
or cut off valve, working in grooves C on the back face of the main slide valve.
The cut off valve is connected with the spindle D by means of a saddle composed
of a plate E and anti-friction pullies F, which, whilst preserving a firm hold upon
the valve, allow of a slight lateral motion, thus accomodating the saddle to the
movement of the valve and preventing frictional strain.
Thirdly. To the means of expanding or forcing the metallic packing rings of the
piston against the inside of the cylinder, and this I accomplish by means of a coiled
spring (after the manner of a hair spring), which is placed within the piston, one
end being secured to a stud and the other end loose, by which means the pressure
of the spring will force the metallic packing-rings against the inside of the cylinder
and top and bottom of piston flanges.
This part of my Invention is illustrated in Figs. 9. and 10, shewing elevation and
plan (partly in section) of my improved packing rings. I employ three rings, a, b, c,
which are nearly triangular in section, and so arranged that the inner ring a when
pressed outward will press the other two rings b and c both against the sides of
the cylinder and against the top and bottom flange d, e. The ring & is pushed
outward by a coiled spring f, one end of which is secured to the stud g.
Having thus described the nature and object of this my said Invention, together
with the manner in which the same may be performed or carried into practical
effect, I would have it understood that I do not confine myself to the precise details
herein shewn and described, as the same may be varied without essentially departing
from my Invention, but what I believe to be new and therefore claim as my
Invention is,-
Firstly. The application of the revolving cam plate H, for purposes substantially
as herein shewn and described.
Secondly. The adjustable universal toe piece J and sliding bar L, acutated by the
governors, substantially as shewn and described.
Thirdly. The means or method of mounting the expansion valve on back of
main slide valve, substantially as herein shewn and described.
Fourthly. The use and employment of a hair spring for forcing the metallic
packing rings of the piston against the inside of the cylinder, substantially as
described.
In witness whereof, I, the said George Sellers, have bereunto set my hand
and seal, this Thirteenth day of August, in the year of our Lord One
thousand eight hundred and eighty one.
GEORGE SELLERS. (L.S.)