IMPROVEMENTS IN STEAM ENGINES
Year: 1873

page_text: LETTERS PATENT to John Frederick Spencer, of the City of West-
minster, Consulting Engineer, for the Invention of "IMPROVEMENTS
IN STEAM ENGINES."
Sealed the 1st January 1874, and dated the 4th July 1873.
PROVISIONAL SPECIFICATION left by the said John Frederick
Spencer at the Office of the Commissioners of Patents, with his
Petition, on the 4th July 1873.
I, JOHN FREDERICK SPENCER, of the City of Westminster, Consulting
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
This Invention relates to improved arrangements or combinations of
the parts of steam engines, which are specially designed for driving the
screw propeller, although they may also be advantageously employed in
other cases admitting of the use of similar engines.
In one arrangement or combination two inverted cylinders placed
above a crank shaft are provided, each with separate steam admission

page_text: valves, and separate exhaust valves, by preference of the kind known as
Corliss valves, such valves being placed transversely as regards the crank
shaft. The valves are worked from eccentrics fixed on a countershaft
placed parallel to and at one side of the crank shaft, there being by
preference separate eccentrics for the admission and exhaust valves,
although the exhaust valves may in some cases be worked from the same
eccentrics as the admission valves. The eccentric rods are jointed to
slide blocks working in guides, and rods jointed to the slide blocks are
connected to "wrist" or oscillating plates mounted on studs on the
cylinder sides, the valve levers being connected to pins on the "wrist" 1
plates by rods as usual with Corliss valve gear. If preferred, the
exhaust valve levers may be connected directly to the slide blocks
instead of to wrist plates, that is, when they are worked by separate
eccentrics.
The counter or valve shaft is driven from the main shaft through 1
gearing arranged for conveniently reversing the engines. A spur wheel
fast on the crank shaft gears with an equal sized spur wheel, which, with
a bevil wheel fast to it, is loose on the countershaft. The bevil wheel
is in gear with an intermediate bevil wheel, which is movable round the
countershaft on a spindle at right angles thereto, and which is in gear 2
with a third bevil wheel fixed on the countershaft. As long as the
spindle of the intermediate bevil wheel is stationary the countershaft
revolves simultaneously with the crank shaft, the eccentrics preserving
their relative positions, but on the intermediate bevil wheel being moved
round the countershaft this shaft is thereby made to change its position 2
relatively to the crank shaft, and the eccentrics are brought into the
relative positions proper for the desired reversed motion of the engines.
The intermediate bevil wheel may be moved or adjusted by hand gear or
by means of a steam cylinder, hand gear being, however, also by pre-
ference, provided in the latter case.
3
In a modified arrangement or combination the valves are placed
longitudinally at the sides of the engines, and are worked from wrist
plates at the ends, the wrist plates being connected to levers, the other
ends of which are connected to the eccentrics on the counter shaft. The
other parts remain substantially as in the arrangement or combination 3
first herein-before described.
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page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Frederick Spencer in the Great Seal Patent
Office on the 1st January 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
FREDERICK SPENCER, of Westminster, in the County of Middlesex,
Consulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of July, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Frederick Spencer, Her
special licence that I, the said John Frederick Spencer, my executors,
administrators, and assigns, or such others as I, the said John Frederick
Spencer, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN STEAM ENGINES," upon the con-
dition (amongst others) that I, the said John Frederick Spencer, my
executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said John Frederick Spencer, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the accompanying
Sheet of Drawings:-
This Invention relates to improved arrangements or combinations of
the parts of steam engines which are specially designed for driving the
screw propeller, although they may also be advantageously employed in
other cases admitting of the use of similar engines.

page_text: Two inverted cylinders placed above a crank shaft are provided each
with separate steam admission valves and separate exhaust valves by
preference of the kind known as "Corliss" valves, such valves being
placed transversely as regards the crank shaft. The valves are worked
from eccentrics fixed on a countershaft placed parallel to and at one
side of the crank shaft, there being by preference separate eccentrics
for the admission and exhaust valves, although the exhaust valves
may, in some cases, be worked from the same eccentrics as the
admission valves. The eccentric rods are jointed to slide blocks
working in guides, and rods jointed to the slide blocks are connected to
"wrist" or oscillating plates mounted on studs on the cylinder sides, the
valve levers being connected to pins on the "wrist plates" by rods, as
usual with Corliss valve gear. If preferred, the exhaust valve levers
may be connected directly to the slide blocks instead of to" wrist plates,"
that is, when they are worked by separate eccentrics.
The counter or valve shaft is driven from the main shaft through
gearing arranged for conveniently reversing the engines. A spur wheel
fast on crank shaft, gears with an equal sized spur wheel, which, with a
bevel wheel fast to it, is loose on the countershaft. The bevel wheel is
in gear with an intermediate bevel wheel, which is movable round the
countershaft on a spindle at right angles thereto, and which is in gear
with a third bevel wheel fixed on the countershaft. As long as the
spindle of the intermediate bevel wheel is stationary the counter-
shaft revolves simultaneously with the crank shaft, the eccentrics
preserving their relative positions, but on the intermediate bevel
wheel being moved round the countershaft, this shaft is thereby made
to change its position relatively to the crank shaft, and the eccentrics
are brought into the relative positions proper for the desired reversed
motion of the engines. The intermediate bevel wheel may be moved or
adjusted by hand gear, or by means of a steam cylinder, hand gear being,
however, also by preference provided in the latter case.
And in order that my Invention, and the manner of performing the
same, may be properly understood, I have hereto appended a Sheet of
explanatory Drawings to be herein-after referred to, and representing, by
way of example, the main features of a pair of engines embodying the
combination or arrangement before described.
View 1 is a side elevation, and view 2 a transverse section of a pair of
engines of the description known as compound. A being the smaller or

page_text: high-pressure cylinder, and B the larger or low-pressure cylinder, each
having in this modification two steam and two exhaust valves of the
description known as "Corliss."
These valves are worked as follows:-A spur wheel D fixed on main
crank shaft C, gears in a spur wheel E of equal diameter, which revolves
freely on a countershaft I placed parallel with crank shaft, and mounted
in proper carriages V, V. This second spur wheel E has secured to it a
mitre or bevel wheel F, and a similar one H is fixed on countershaft I
at a certain distance from the first; the power required to drive the
countershaft being transmitted from one to the other through a third
mitre or bevel planet wheel G, mounted on a spindle O, the lower end of
which works on the countershaft as a fulcrum, a bearing being formed,
half in enlarged end of spindle, and half in a frame P, to which it is
secured. This planet wheel can now be moved round on the counter-
shaft by means of a hand wheel R, connected with a worm Q, which
works in suitably formed teeth on lower side of frame P, thus altering
the position of the countershaft relatively to the crank shaft, as required
for the purpose of starting or reversing engines; and this motion may be
performed either wholly by hand power or with the assistance of a
cylinder S, the piston T of which is connected with frame P at pin U,
steam or water from boiler being admitted to either side of piston by
suitably arranged valves.
The steam and exhaust valves of each cylinder are worked from pins
L, L, placed eccentrically in discs K, K, secured to each end of counter-
shaft I, which pins, being connected to sliding blocks M, M, and the
latter to the "wrist plates" N, N, work the valves in the usual manner,
as is well understood.
In carrying out this Invention eccentrics may be substituted for the
discs & pins, and separate eccentrics may be used for working the steam
and the exhaust valves, in which case double " wrist plates" are required,
or, if preferred, the exhaust valves may be worked direct without the
intervention of a "wrist plate."
Although the engine shewn in the accompanying Drawing is of the
kind known as compound, it is obvious that the gearing and connections
for working the valves herein-before described may also be applied to
engines in which the expansion of the steam is begun and completed in
the same cylinder.

page_text: Having thus particularly described this Invention, and the manner in
which it is to be performed, I claim the method, substantially as herein
described, of working the steam and the exhaust valves of steam engines
when such valves are of the "Corliss" kind, worked transversely to the
engine shaft by means of cranks or eccentrics on a counter shaft parallel
to the crank shaft and connected thereto by bevel planet gearing, whereby
the engines can be readily reversed.
In witness whereof, I, the said John Frederick Spencer, have
hereunto set my hand and seal, this First day of January, in
the year of our Lord One thousand eight hundred and seventy-
four.