IMPROVEMENTS IN STEAM ENGINES
Year: 1873

page_text: LETTERS PATENT to William Inglis, of Bolton-le-Moors, in the
County of Lancaster, and John Frederick Spencer, of the City
of Westminster, Engineers, for the Invention of "IMPROVEMENTS IN
STEAM ENGINES."
·Sealed the 30th December 1873, and dated the 4th July 1873.
PROVISIONAL SPECIFICATION left by the said William Inglis and
John Frederick Spencer at the Office of the Commissioners of
Patents, with their Petition, on the 4th July 1873.
We, WILLIAM INGLIS, of Bolton-le-Moors, in the County of Lan-
caster, and JOHN FREDERICK SPENCER, of the City of Westminster,
Engineers, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN STEAM ENGINES," to be as follows:-
! This Invention has for its object to improve the action of steam
engines, and consists in applying to each end of each cylinder a small
additional steam admission valve to admit a little steam in each case,
by preference after the respective exhaust has terminated, and just
prior to the end of the stroke, in order to provide an earlier and denser

page_text: cushion at the end of the stroke than can be conveniently obtained
with ordinary valves, either by causing the exhaust to terminate early,
or by giving lead to the steam admission, and also to prevent percussive
action by the sudden entrance of a large quantity of steam on the quick
opening of the main valve.
Hitherto, in adjusting the movements of the existing steam admission
and exhaust valves restrictions have been imposed by the necessity of
arranging them to work with the least possible percussive action, but
when such action is completely provided against, as it is by the small
additional admission valves, the action of the main valves may be most
conveniently arranged to give the best results quite independently of
the restrictions referred to.
By a second improvement the steam admitted by the additional
valves instead of being of the same temperature as that entering by
the main valves is superheated, in order that by imparting heat to
the cylinder to neutralise the cooling action due to the exhaust, the
condensation of the fresh steam entering by the main valves may be
diminished, and that without the tendency to injure the main valves
and port faces which exists when the whole supply of steam is super-
heated.
The additional valves may be small equilibrium valves worked from
the engine shaft, or from any conveniently revolving, reciprocating, or
oscillating part of the engines, the working details being by preference
made adjustable so as to vary the admission of steam, as regards period
or quantity, as may be found desirable or requisite, and being also made
capable of being thrown out of gear when required, as for example, in
the case of marine engines when working very slowly, or manoeuvring.
Also, instead of there being a separate valve to each end of each
cylinder, a single slide valve may be arranged to work over two ports
-leading to the cylinder ends.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Inglis and John Frederick Spencer in the
Great Seal Patent Office on the 2nd January 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
INGLIS, of Bolton-le-Moors, in the County of Lancaster, and JOHN
FREDERICK SPENCER, of the City of Westminster, Engineers, 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-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said William Inglis and John
Frederick Spencer, Her special licence that we, the said William Inglis
and John Frederick Spencer, our executors, administrators, and assigns,
or such others as we, the said William Inglis and John Frederick
Spencer, our 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 condition (amongst others)
that we, the said William Inglis and John Frederick Spencer, our
executors or administrators, by an instrument in writing under our,
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 we, the said William Inglis and John Frederick
Spencer, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement in writing, reference
being had to the accompanying Drawings, that is to say :-
Our said Invention has for its object to improve the action of steam
engines, and consists in applying to each end of each cylinder a small
additional steam admission valve to admit a little steam in each case,

page_text: by preference after the respective exhaust has terminated and just prior
to the end of the stroke.
By a further improvement we cause superheated steam to be admitted
by the additional valves, herein-before referred to, instead of steam of
the same temperature as that entering by the main valves.
And in order that our said Invention and the manner of performing
the same may be properly understood, we hereunto append a Sheet of
explanatory Drawings to be herein-after referred to, and showing a
simple and convenient arrangement for practically applying our im-
provements. In these Drawings the same reference numerals are used
to mark the same or like parts wherever they are repeated.
Figure 1 of the Drawings is a sectional side elevation, and Figure 2
is a vertical section as at right angles to Figure 1, showing a portion of
an inverted cylinder steam engine. The cylinder 1 is shown as formed
with the usual passages and ports 2, 3, 4, for the main supply of steam, 1
an ordinary slide valve 5 being provided for distributing that steam; it
must however be understood that our improvements are applicable in
combination with most of the existing arrangements of main valve
apparatus.
For the purposes of our Invention the cylinder 1 is made with two a
additional passages 6, 7, one at each end, each of these passages being
controlled by valves 8, 9, which are represented as of the equilibrium
or double-beat kind, and which are moved by spindles 10, 11, passing
out through stuffing boxes. The valve spindles 10, 11, are acted on
by cam slide blocks 12, 13, carried in guide grooves formed on brackets a
14, 15, which are cast in connection with the casings containing the
valves 8, 9. The cam blocks 12, 13, are connected by rods 16, 17,
with right-and-left screw couplings to bell-crank levers 18, 19, which
are connected by a rod 20, and of which one 19 is connected by a rod 21
to the air-pump lever 22 of the engine.
3
The motions of the valves 8, 9, may be derived in any other con-
venient way, or from any suitably moving part of the engines; whilst
various kinds of valves may be substituted for those 8, 9, shown.
By using small additional steam admission valves in the manner
herein-before described, an carlier and denser cushion can be provided å
at the end of the stroke than is conveniently obtainable with ordinary
valves, either by causing the exhaust to terminate carly, or by giving

page_text: lead to the steam admission, and the admitting of a little steam in this
way in anticipation of the main supply serves also to prevent percussive
action by the sudden entrance of a large quantity of steam on the quick
opening of the main valve.
Hitherto, in adjusting the movements of the existing steam admission
and exhaust valves restrictions have been imposed by the necessity of
arranging them to work with the least possible percussive action; but
when such action is completely provided against, as it is by our small
additional admission valves, the action of the main valves may be
most conveniently arranged as regards the various parts of their action
to give the best results quite independently of the restrictions referred
to.
The using of our small additional valves (8, 9,) to admit superheated
steam, or steam of higher temperature than that of the main supply,
will have the important practical advantage of imparting heat to the
cylinder to neutralise the cooling action which is due to the exhaust,
and which ordinarily induces considerable condensation of the steam
freshly entering the cylinder without the tendency to injure the main
valves and port faces which exists when the whole supply of steam is
superheated.
We prefer to arrange the actuating mechanism of our small additional
steam admission valves so as to be adjustable for the purpose of varying
the admission of steam by them, as regards period or quantity, as may
be found desirable or requisite in practice; and the valves may also be
made capable of being thrown out of gear or otherwise rendered inactive
when desirable, as for example, in the case of marine engines when
working very slowly or manoeuvring in or near port.
In the example shown in the Drawings the adjustment can be effected
by turning the couplings of the rods 16, 17, so as to alter the effective
lengths of these rods.
In the Drawings pipes 23, 24, are shown for leading steam to the
casings of the valves 8, 9, these being branch pipes from the main steam
pipe or valve chest, or from a superheater.
In the case of compound engines the small additional valves of the
low-pressure cylinder may receive the steam from the receiver or inter-
mediate valve casing, or from a superheater.

page_text: Instead of there being a separate valve (8, 9,) to each end of each
cylinder, a single slide valve may be arranged to work over two ports
leading to the cylinder ends.
Having thus particularly described our said Invention, and the
manner of performing the same, we have to state that we do not
restrict ourselves to the precise details herein described or delineated,
but that what we believe to be novel and original, and claim as the
Invention secured to us by the herein-before in part recited Letters
Patent is,-
1. The providing of steam engine cylinders with small additional
steam admission valves, as and for the purposes herein-before described.
2. The admitting to steam engine cylinders at the commencement of
each stroke of supplies of steam which are separate from the main
supplies, and which are superheated, or of higher temperature than the
main supplies, as and for the purposes herein-before described.
In witness whereof, I, the said William Inglis, on behalf of myself
and 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.
WILLIAM INGLIS. (L.S.)