CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1847

page_text: BACON AND DIXON'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
BACON, and THOMAS, DIXON, both of Bury, in the County of Lancaster,
Engineers, send greeting.
4
WHEREAS, Her present most Excellent. Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Nineteenth day of August, in the eleventh year of Her reign,
and in the year of our Lord One thousand eight hundred and forty-seven, did,
for Herself, Her heirs, and successors, give and grant unto us, the said
William Bacon and Thomas Dixon, Her especial licence, full power, sole
privilege and authority, that we, the said William Bacon and Thomas Dixon,
our executors, administrators, and assigns, and such others as we, the said
William Bacon and Thomas Dixon, our executors, administrators, or assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein expressed, should and lawfully might
make, use, exercise, and vend, within England and Wales and the Town
of Berwick-upon-Tweed, our Invention of "CERTAIN IMPROVEMENTS IN STEAM
ENGINES;" in which said. Letters Patent is contained a proviso that we, the
said William Bacon and Thomas Dixon, shall cause a particular description
of the nature of our said Invention, and what manner the same is to be
performed, to be enrolled in Her Majesty High Court of Chancery within
six calendar months next and immediately after the date of the said in
part recited Letters Patent, as in and by the same, reference being thereunto
had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, we, the said
William Bacon and Thomas Dixon, do hereby declare that the nature of the
said Invention, and the manner in which the same is to be performed,
is particularly described and ascertained in and by the Drawings hereto
annexed, and the following explanation thereof (that is to say) :-
Our Invention of Improvements in Steam Engines apply to that class of
steam engines generally termed Woolf's, or compound cylinder engines, and in
one case, herein-after specified, is also applicable to single cylinder engines.
In the ordinary arrangement of compound cylinder engines the content of the
passage (from the exhausting valve for the high-pressure cylinder to the inside
of the low-pressure cylinder) forms a large proportion to the content of the
high-pressure cylinder; this content or space is filled (at the conclusion of
each stroke, whether upwards or downwards, of the low-pressure piston)
with steam of the same density as in the low-pressure cylinder, which in many
cases is six or seven pounds below the pressure of the atmosphere, or even of
still less density. On the return of the pistons the steam used in the preceding
stroke of the piston in the high-pressure cylinder is admitted into the passage
or space above mentioned, and into the low-pressure cylinder, mixing with
the above-mentioned rarified steam, and consequently the steam, in pro-
ceeding from the high-pressure cylinder, is considerably reduced in pressure
without producing a corresponding useful effect on the pistons.
The principal objects of our improvements are to remedy in a great measure
the defect above mentioned, and at the same time to simplify the construction
and increase the efficiency of compound cylinder engines; to effect which
objects, we arrange the passages, valves, and openings in such a manner that
the exhausting valves for the high-pressure steam cylinder (or steam valves for
the low-pressure steam cylinder) are placed as near as possible to the ports
or entrances of the low-pressure cylinder. In consequence of these arrange-
ments the passage between the steam valve for either end of the low pressure
cylinder and the opposite end of the high-pressure cylinder is constantly filled
with steam of the same density as that in the high-pressure cylinder, therefore
the contents of the passage, from the valve to the entrance of the low-pressure
cylinder, is the extent of the increase of space the steam will have to occupy for
the commencement of the stroke of the low-pressure piston, consequently the
pressure of the steam will be reduced, but in a very slight degree, and we
thereby obtain a more perfect expansion of the steam in the cylinder, and pro-
duce a more effective motive power from the engine.
Our improvements consist, firstly, in arranging the valves, openings, and
passages in such a manner that one valve box and one double hollow valve, or

page_text: two sliding valves of the common form, are adapted to serve for both high and
low-pressure cylinders; the same passage in the valve which admits steam to
the top of the low-pressure cylinder (from the bottom of the high-pressure
cylinder), in the downward stroke of the pistons, also forms the passage from
the top of the low-pressure cylinder to the condenser in the upward stroke of
the pistons, and the same passage in the valve which admits the steam to the
bottom of the low-pressure cylinder (from the top of the high-pressure cylinder),
in the upward stroke of the pistons, also forms the passage from the bottom of
the low-pressure cylinder to the condenser in the downward stroke of the
pistons, and the same part of the valve which admits the steam to the low-
pressure cylinder forms the exhausting valve for the opposite end of the high-
pressure cylinder.
Secondly, our improvements consist in using separate plate or other valves
for the admission of steam to the high-pressure cylinder, using these valves. as
expansion valves to cut off steam from the high-pressure cylinder, and ar-
ranging them so that the amount of expansion may be varied to any required
extent in the high-pressure cylinder, without interfering with the ingress or
egress of steam to and from the low-pressure cylinder.
Thirdly, our improvements consist in arranging conical cornish or other
description of disc valves for compound cylinder engines, so as to effect the
same object as by the slide valves above described, and in arranging each valve
to be lifted up by a separate tappet (or by other mechanical means), so that
any one valve can be closed without interfering with any of the others, and by
which means any amount of expansion or compression of steam in either high
or low pressure cylinder can be obtained.
In order that the practical application of our improvements may be more
fully explained and better understood, we have attached to these presents four
Sheets of Drawings, representing our several improvements, being drawn to a
scale of about one inch to a foot, and shewn as applied to vertical cylinders
placed side by side, and with the valves in the position for effecting the down-
ward stroke of the pistons; but of course it will be evident that the same ar-
rangement of valves, passages, &c., will be equally applicable to vertical
cylinders placed opposite the end of each other (in which one piston rod serves
for both high and low pressure-pistons, and in either case, (whether the cylinders
are placed side by side or opposite the end of each other), the cylinders may be
placed in vertical, horizontal, or inclined positions.
In Sheet 1 Figures 1, 2, 3, and 4, represent an arrangement, by which one
valve box, six openings, and two common single hollow sliding valves are
adapted to serve both high and low pressure steam cylinders. Figure 1 shew-

page_text: ing a vertical section of the passages and the high-pressure cylinder in eleva-
tion. Figure 2 is a transverse section through the low-pressure steam cylinder
valve, casing, and passages. Figure 3 is a section of the valve casing and
valves, and elevation of the high-pressure cylinder. Figure 4 is a plan view
of the same (with pistons removed), shewing sections of high and low pres-
sure steam cylinders and section of valve casing and passages. A is the valve
casing B, the high-pressure steam cylinder; C, the low-pressure steam
cylinder; and D, the piston for the low-pressure cylinder. a is the entrance
and exit opening for steam for the top of the cylinder B, and a¹ is the
entrance and exit opening for steam for the bottom of the cylinder B. b, b,
is the entrance and exit opening and passage for the top of the cylinder C, and
61, 61, is the entrance and exit opening and passage for the top of the cylinder C.
c, c', are exhaust openings for the top and bottom of the cylinder C. d is
the passage from the opening a to the top of the cylinder B. d¹ is the
passage from the opening a, a', to the bottom of the cylinder B. e, c', are the
top and bottom slide valves, the valve e being adapted to give direction to the
current of steam to and from the bottom of high-pressure cylinder B, and to
and from the top of low-pressure cylinder C, and the valve e¹, being adapted
to give direction to the current of steam to and from the top of cylinder B,
and to and from the bottom of cylinder C. f.f, is a lap on one end of each
valve to cover alternately the exhaust openings c, c¹.
Figures 5, 6, and 7 represent an arrangement, by which one valve casing,
five openings, and one double hollow slide valve are made to serve for
two high-pressure cylinders and one low-pressure cylinder; Figure 5 being a
section of the valve casing and passages; Figure 6, a transverse section of the
same; and Figure 7, a face view of the double hollow slide valve. The same
description and letters of reference will apply to these as to the preceding
Figures, excepting that the laps f,f, above described, are dispensed with, and
the exhaust opening c is used for both the top and bottom of cylinder C, and
is covered alternately by the hollows of the valve e¹, e. The working of the
engine is as follows:-The steam is conveyed from the boiler into the valve
casing A, passes through the opening a and passage d to the top of the high-
pressure cylinder B, at the same time the steam from the bottom of the said
cylinder B passes through the passage d' and opening a¹ through the valve e
and opening and passage b. to the top of the low-pressure cylinder C,
whilst the steam from the bottom of the said cylinder C passes through
the passage and opening 61, valve e¹, and opening c¹, to the exhaust
pipe and condenser, and the lap f, on the valve e, covers the upper
exhausting opening c leading to the condenser.
When the motion of

page_text: the pistons is reversed, the steam from the valve casing A passes through
opening a and passage d to the bottom of the high-pressure cylinder
B, at the same time the steam from the: top of the said cylinder B
passes through the passage d'and opening a, through the valve e and
opening and passage b, to the bottom of the low-pressure cylinder C, whilst
the steam from the top of the said cylinder C passes through the passage and
opening 6, valve e, and opening c, to the exhaust pipe and condensor, and the
lapf, on the lower valve e¹, covers the exhausting opening c¹, leading to
condensor.
In Sheet 2 of the Drawings, Figures 1, 2, 3, and 4 represent an arrange-
ment by which one valve box, eight openings, two plate expansion valves, and
two common single hollow sliding valves, are adapted to serve for one high-
pressure cylinder and one low-pressure cylinder; Figure 1 being a vertical
section of the passages, &c., and Figure 2 a transverse section of the same,
exhibiting the low-pressure cylinder and valve casing, also in section; Figure 3
is an elevation of the high-pressure cylinder, with the front of the valve casing
removed so as to shew the arrangement of the several openings; and Figure 4
is a face view of the valves. A is the valve casing; B, the high-pressure steam
cylinder; C, the low-pressure steam cylinder; and D, the piston for cylinder C.
a is the opening for admitting the steam from the valve casing to the top of the
cylinder B; a' is the opening for admitting the steam from the valve casing to
the bottom of the cylinder B; b, valve for covering the opening a, and 6¹ the
valve for covering the opening a'. The valves b, b¹, are furnished with suitable
apparatus for regulating the amount of expansion in the high-pressure cylin
der; c is the valve for the top of cylinder C, and c¹ the valve for the bottom
of the same; d is the opening for admitting steam from the bottom of cylinder
B to the valve c, for the top of cylinder C, and d¹ is an opening for admitting
steam from the top of the cylinder B to the valve c', for the bottom of the
cylinder C; e is the entrance and exit opening and passage for the top of the
cylinder C, e is the entrance and exit opening, and passage for the bottom of
the cylinder C; is an exhaust opening leading to the condensor from the top
of the cylinder C; f¹ is an exhaust opening leading to the condensor from the
bottom of the cylinder C; g is a passage connecting the opening a, the top of
the cylinder B. and the opening d; g. is a passage connecting the opening a¹,
the bottom of the cylinder B, and the opening d; h, h, are the laps of the
valves c, c¹, to cover alternately the openings f, d, and f, d. The steam is
conveyed from the boiler into the valve casing A, passes through the opening
a along the passage 9 into the top of the cylinder B, filling at the same time
the passage 9 as far as the opening d, which is covered by the lap h on the top

page_text: of the valve c'; the steam from the bottom of the cylinder B passes along the
passage g to the opening d, through the valve c, and opening and passage e, to
the top of the cylinder C. At this time the expansion valve 1 covers the opening
a', whilst the steam from the bottom of the cylinder C passes through the passage
and opening e', valve c¹, and opening f¹, to the condensor, and the lap h, on the
top of the valve c, covers the top exhausting opening f, and the lap h, on top
of the valve c', covers the steam opening d. To effect the ascending stroke of
the pistons the valves are then reversed, the steam from the valve casing passes
through opening a', passage g¹, into the bottom of cylinder B, filling at the
same time the passage g¹, as far as opening d, which is then covered by the
lap h, on the bottom of the valve c; the steam from the top of cylinder B
passes along the passage g to the opening d¹, through the valve c', the opening
and passage e¹, to the bottom of cylinder C. At this time the expansion valve
6 covers the opening a, whilst the steam from the top of cylinder C passes
through the passage and opening e, valve c, and opening f, to the condensor,
and the lap h, on the bottom of the valve c', covers the bottom exhausting
opening f, and the lap h, on the bottom of the valve c¹; covers the steam
opening d. Independently of the simplicity of these arrangements, the object
here aimed at is to produce a greater effective pressure on the low-pressure
piston at the commencement of its stroke, and consequently a greater average
pressure throughout the stroke.
In Sheet 3 of the Drawings, Figures 1, 2, and 3 shew an arrangement, by
which conical, cornish, or other description of disc valves, are adapted to serve
both high and low pressure steam cylinders; Figure 1 being an elevation of
the high and low pressure cylinders, shewing in section the passages which
communicate between the same; Figure 2 is a section taken through the
valve casing and side pipes, shewing the arrangement of the valves; and
Figure 3. is an horizontal section of the valve casing and high and low pressure
cylinders. A is the valve casing; B, the high-pressure cylinder; C, the low-
pressure cylinder. a is the steam valve for the top of cylinder B; a', the
steam valve for the bottom of cylinder B. 61 is the steam valve for the top
of cylinder C, and exhausting valve for bottom of the cylinder B; 6' is the
steam valve for bottom of cylinder C, and exhausting valve for the top of
cylinder B. c is the opening and passage to the top of the cylinder C, and
c¹ is the opening and passage to the bottom of the cylinder C; d is the ex-
hausting valve to the condensor from the bottom of the cylinder C; d¹ is the
exhausting valve to the condensor from the top of the cylinder C. e is a
from the bottom of the cylinder B to the steam valve for the top of
cylinder C; and e¹ is a passage from the top of the cylinder B to the steam
passage

page_text: valve for the bottom of the cylinder C. The steam is conveyed from the
boiler into the valve box A, and passes through the valve a, and passage e¹, to
the top of the high-pressure cylinder B; at the same time the steam from
bottom of the cylinder B passes through the passage e, and valve b, through
the opening c, to the top of the cylinder C. whilst the steam from the bottom
of the said cylinder C passes through the opening and passage c', and valve d,
through the exhaust pipe to the condensor. When the motion of the pistons
is reversed the steam will pass through valve a, and passage e, to bottom of the
cylinder B; at the same time the steam from the top of the said cylinder B
passes through the passage e', and valve b', through opening c', to the bottom
of the cylinder C, whilst the steam from the top of the said cylinder C passes
through the opening and passage c, and valve d', through the exhaust pipe, to
the condensor.
Sheet 4 of the Drawings shews another arrangement by which conical,.
cornish; or other disc valves are adapted to serve for both high and low pres-
sure cylinders; Figure 1 being an elevation of the valve casing and side pipes,
shewing the arrangement for working the valves; Figure 2 is a vertical
section taken through the passages which communicate between the high and
low pressure cylinders; Figure 3 is a section of the valve casing and side
pipes, shewing the position of the valves; and Figure 4 an horizontal section
of the valve casing and high and low pressure steam cylinders. It is unnecessary
to describe the working of this arrangement, as the same description will
answer for this as for Sheet 3; similar letters of reference being placed upon
corresponding parts of the mechanism in both Sheets of the Drawings.
In connection with the before-mentioned improvements we also use an
improved method (when starting an engine) for what is technically termed
blowing through. This improved method is for the purpose of preventing the
engine from starting in the wrong direction, and consists in arranging two
passages from the blow-through valve to the low-pressure cylinder. One of
these passages being connected from the blow-through valve to the top of the
low-pressure cylinder, and the other passage from the blow-through valve to
the bottom of the low-pressure cylinder, and the openings into these passages
regulated in such a manner (by cock, sliding, or conical valves) that when the
operation of blowing through is performed, the steam is admitted simul-
taneously to each side of the piston, and when the said valve is closed there
is no communication between one passage and the other.
In Sheet 4 of the Drawings, Figure 5 represents an arrangement of three-
way cock and passages in section. To obtain the object we have in view, a is
the blow-through cock and stopper; b, the passage for steam from boiler or

page_text: engine valve casing to a; c is the passage from the cock a to the top of
cylinder, and c, the passage from the cock a to the bottom of the cylinder.
The Drawing represents the cock open, and it will be evident that the openings
to passages c, c¹, will be simultaneously closed by moving the stopper one
quarter round.
Having now fully described the nature and object of our said improve-
ments, together with the method of carrying the same into practical effect, we
would remark, in conclusion, that we do not claim as of our Invention the
application or use of a single valve box to one high-pressure and one low-
pressure steam cylinder, but what we claim is,-
Firstly, the peculiar arrangement of the valves and openings, as shewn in
the Drawings, and above particularly described, that is, the adaptation and appli-
cation of a reduced number of valves of the ordinary construction to effect the
necessary communication between the steam chest cylinders and condensor, and
the arrangement of ports whereby the steam is reduced as little as possible
in passing from the high-pressure to the low-pressure steam cylinder.
Secondly, we claim the application of two high-pressure steam cylinders to
one low-pressure steam cylinder, and the arrangement of the steam ports
whereby the same number of valve boxes, valves, and openings which serve for
one high and one low pressure steam cylinder, will also serve for two or more
high-pressure steam cylinders and one low-pressure steam cylinder.
Thirdly, we desire it to be understood that we do not confine the application
of our improvements exclusively to compound cylinder engines with conden -
sation, but we also claim the application of these improvements to compound
cylinders without condensation, passing the steam from the second or low-
pressure cylinder into the atmosphere instead of a condenser.
And, lastly, we claim the application of our improved method of blowing
through for starting engines as applicable to all descriptions of double-acting
condensing engines, whether with compound or single cylinders; and we also
claim any combination of our improvements, whereby the objects described in
this Specification may be accomplished.
In witness whereof, we, the said William Bacon and Thomas Dixon,
have hereunto set our hands and seals, this Seventeenth day of
February, in the year of our Lord One thousand eight hundred and
forty-eight.
WILLIAM (L.S.) BACON. THOMAS (L.S.) DIXON.

page_text: AND BE IT REMEMBERED, that on the same Seventeenth day of
February, in the year above mentioned, the aforesaid William Bacon and
Thomas Dixon came before, our Lady the Queen in Her Chancery, and
acknowledged the Specification aforesaid, and all and every thing therein con-
contained, in form above written. And also the Specification aforesaid was
stamped according to the tenor of the Statute in that case made and
provided.
Inrolled the Eighteenth day of February, in the year above written.