IMPROVEMENTS IN STEAM ENGINES.
Year: 1874

page_text: LETTERS PATENT to William Dawes, of Kingston Grove, Leeds, in
the County of York, Engineer, and Henry Percy Holt, of Royal
Insurance Buildings, Leeds, in the County of York, Civil Engineer,
for the Invention of
86
IMPROVEMENTS IN STEAM ENGINES.' "
PROVISIONAL SPECIFICATION left by the said William Dawes and
Henry Percy Holt at the Office of the Commissioners of Patents,
with their Petition, on the 15th May 1874.
We, WILLIAM DAWES, of, Kingston Grove, Leeds, in the County of
York, Engineer, and HENRY PERCY HOLT, of Royal Insurance Buildings,
Leeds, in the County of York, Civil Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN STEAM ENGINES," to be
as follows:-
:-
The first part of this Invention consists in obtaining by an improved:
arrangement of certain parts, and the combined employment of others, :
an engine of the vertical, compound,. condensing type or construction,.

page_text: which shall embody features of ccxellence or desirability which such
engines have not hitherto collectively possessed; it may be thus
described: Upon a pair of "A frame" or other strong and suitable
standards we fix either with or without an additional or intervening
table or platform, the two usual "double-acting" steam cylinders with
their pistons and rods inverted, and so placed that their "line of centres"
shall be at right angles to the crank shaft which lies transversly of tho
before-named standards, and, by preference, with the centre of the larger
or "low-pressure" cylinder directly over the crank or crank pin bearing,
as in ordinary "direct acting" inverted engines.
The position of the smaller or "high-pressure" cylinder upon the
said standards, and with respect to the "low-pressure" cylinder, is
parallel with and as near to it as the separating or distributing valves will
permit; then, for the purpose of obtaining a reverse or contrary action
of the two pistons with the attendant advantages, both of balance and
economy through small amount of
clearance," we employ an
arrangement of levers or "beams" for coupling and transmitting the
power or thrust of the high-pressure piston, which shall at the same
time constitute a "parallel motion" guide to both the piston rods and of
the strongest and most durable kind, as the proper areas or proportions
of the "bearings or working surfaces and other parts, for the first-named
duly. (transmitting) will render the second (guiding) so comparatively
or proportionately small or "light" as to produce scarcely any wear or
alteration in them.
"
"
The before-named lever and "parallel motion" arrangement consists,
first, of a pair of "half beams or levers of the second order, the inner
ends of which are coupled to the piston rods (one to each), and the outer
ends to a pair of upright "reeling frames" or standards carried by
brackets and "bearings" upon the outer sides or edges of the main
standards, and thus causing the said "half beams or levers to lie "end
to end of each other, and separated by the necessary or given distance
between the two cylinder centres; then to a pair of "gudgeons" (one
to each) fixed through and into these half beams, at a point or distance
along them suitable for the "parallel motion" or guiding duty or effect,"
we couple the ends of a strong double beam or lever of the first order
set sufficiently wide between the "cheeks" or "flitches" to admit the
said half beams with the piston rod ends and bearings between them;
the bearings of the central "main gudgeon" which carries this central

page_text: The second part of this Invention consists in the double or twofold
use of a horizontal cylinder and piston (placed on the centre line of the
main shaft, coupled by means of rods or otherwise to the crank pin),
with suitable valves, gear, and connections to enable it to act as an air
pump for the condenser, and when required as a steam cylinder and
piston for the purpose of obtaining, virtually at the time of starting or
reversing, the effect or convenience of pair of engines without a dead
centre.
The above position of this cylinder refers only to vertical engines, but
in its application to other kinds the said combined "air pump" and
pusher" is still placed at right angles or thereabouts to the main
cylinders with suitable valves and gears, which can be thrown in or out
of action for either duty. This arrangement is more particularly useful
in marine engines to be used as a "pusher" or pair of engines when
entering or leaving port, and at other times as an air pump in the usual
manner.
The third part of this Invention consists in a novel and more com-
plete arrangement of apparatus than has hitherto been used for starting,
stopping, reversing, and controlling, "or handling" steam engines of
such dimensions as cannot be "handled" by manual power alone. For
this purpose we employ as the motive power a steam cylinder and piston,
with the necessary and convenient valve arrangement for admitting
steam to or exhausting from either side of piston, and in connexion with
these we employ either a second cylinder and piston or a pair of plungers
or "rams" and suitable working barrels (which may when desirable be
considerably smaller in area than the steam cylinder and piston before.
named), which thro' the medium of water, oil, or other liquid, shall
check or control the speed and distance traversed by these parts and
their effect upon the gear and valves of the engine to which they aro
connected.
For the purpose of obtaining absolute control we employ a peculiar
arrangement of valves or their equivalent in connection with the liquid
or controling cylinders or barrels, these being so arranged that whilst the
exit valves or appertures are contracted to a sufficient extent for checking
the speed, or entirely closed for holding (as before explained) the inlet
valves for readmitting the liquid on the return stroke, are of more ample
arca in consideration of the difference of the pressure during exit and
maturn

page_text: For the sake of simplicity of arrangement and also the working, all
the before-named valves or equivalents are connected with and actuated
by the starting or reversing lever. Thus by the employment of thic
before-named apparatus, in which is embodied both the variable opening
and entire closing of the appertures or passages for regulating the escape
of the liquid, perfect control is obtained by merely sufficient manual
power to work this small valve gear instead of the main gear of the
engine.
In some cases we employ the above-named combined steam and liquid
controling apparatus for governing the cut-off and ratio of expansion of
the engine (thro' the medium of link or other motion) by connecting
the valve gearing of the same with a governor, which by this arrange-
ment only has to overcome the resistance of this small valve gear
instead of that of the engine main valves, and therefore is more rapid
and efficient in its action.
:
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said
William Dawes and Henry Percy Holt in the Great Seal Patent
Office on the 19th November 1874.
:
TO ALL TO WHOM THESE PRESENTS SHALL COME, WC, WILLIAM
DAWES, of Kingston Grove, Leeds, in the County of York, Engineer, and
HENRY PERCY HOLT, of Royal Insurance Buildings, Leeds, in the
County of York, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of May, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said William Dawes and Henry
Percy Holt, Her special licence, that we, the said William Dawes and
Henry Percy Holt, our executors, administrators, and assigns, or sucli
others as we, the said William Dawes and Henry Percy Holt, 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,
£

page_text: 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 Dawes and Henry Percy Holt, 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 on or before the Twentieth day of November One thousand eight
hundred and seventy-four.
NOW KNOW YE, that we, the said William Dawes and Henry Percy
Holt, 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 :-
:_
The first part of this Invention consists in obtaining by an improved
arrangement of certain parts, and the combined employment of others,
an engine of the vertical, compound, condensing type or construction,
which shall embody features of excellence or desirability, which such
engines have not hitherto collectively possessed; it may be thus
described-Upon a pair of "A frame" or other strong and suitable
standards we fix, either with or without an additional or intervening
table or platform, the two usual." double-acting" steam cylinders, with
their pistons and rods inverted, and so placed that their "line of centres "
shall be at right angles to the crank shaft which lies transversely of the
before-named standards; and by preference with the centre of the
.larger or low pressure" cylinder, directly over the crank or crank pin
bearing, as in ordinary "direct-acting" inverted engines.
<
The position of the smaller or high-pressure" cylinder upon the
said standards, and with respect to the "low-pressure" cylinder is
parallel with, and as near to it as the separating or distributing valves
will permit; then for the purpose of obtaining a reverse or contrary
action of the two pistons, with the attendant advantages both of balance
and economy through small amount of "clearance." We employ an
arrangement of levers or "beams" for coupling and transmitting the
power or thrust of the high-pressure piston, which shall at the same
time constitute a "parallel motion" guide to both the piston rods, and
of the strongest and most durable kind, as the proper areas or pro-

page_text: portions of the "bearings" or working surfaces and other parts, for
the first named duty (transmitting) will render the second (guiding) so
comparatively or proportionately small or "light" as to produce scarcely
any wear or alteration in them.
The before-named lever and "parallel motion" arrangement consists
first, of a pair of "half beams" or levers of the second order, the inner
ends of which are coupled to the piston rods (one to each), and the
outer ends to a pair of upright "reeling frames or standards, carried
by brackets and bearings" upon the outer sides or edges of the main
standards or from the cylinders, and thus causing the said "half beams"
or levers to be at the necessary or given distance between the two cylinder
centres; then to a pair of "gudgeons" (one to each) fixed through and
into these half beams, at a point or distance along them, suitable for the
"parallel motion" or guiding duty or effect, we couple the ends of a
strong double beam or lever of the first order, set sufficiently wide between
the "checks or "flitches" to admit the said half beams with the piston
rod ends and bearings between them; the bearings of the central "main
gudgeon" which carries this central beam or lever, being secured to tho
cross bar or other suitable part of the main standards. The whole of
the bearings of or connected to all three beams or levers, being on the
same horizontal planc or level, when the two pistons are level with or
opposite to each other, or at "half stroke."
"
"
"
:
""
The upper end of the one connecting rod" which transmits the
power or thrust of both the pistons is coupled or jointed to the "low
pressure" piston rod, working upon the same "pin or gudgeon
which is secured to or "fixed in" the inner end of one of the first named
half beams or levers, the lower end (of the connecting rod) being
attached to the crank in the usual manner, thus constituting the "low
pressure" and most powerful cylinder, and part of the engine "direct
acting," and that of the best kind or construction, having a strong
simple and durable "parallel motion" in lieu of the ordinary "slides"
and blocks.
"
We prefer to use for one of the air pumps a single-acting or lifting
vertical "air pump," and we place and work this as well as the
"
boiler or other pumps under the high-pressure side or part of the
engine, so that their "duty" will assist in perfecting the balance of the
whole engine.

page_text: The cylinder valves of this engine may be of any convenient kind or
type, but we prefer to use a pair (one top and one bottom) of simple
slide valves with "governable" expansion plates and gear for the first
or admission valves; a-pair of "gridiron" valves working horizontally
for the separating or distributing valves, and a pair of simple slides
(reversed) for the exhaust valves of the low-pressure cylinder; though
in some cases we use one long valve or one pair coupled in lieu of the
three pairs first described.
○ The necessary gear and intervening connecting parts for giving
motion to these valves may be of any convenient kind, according to the
valves employed; but when three pairs of valves are used we prefer to
employ reciprocating cams for the intermediate and exhaust valves, for
the purpose of obtaining rest except at the time of opening or closing;
the high-pressure valves having the ordinary motion; and we generally
use two link motions, one for admitting the other exhausting, with
suitable connections for the exact timeing of the valves.
The second part of this Invention consists in the double or twofold
use of a horizontal cylinder and piston (placed on the centre line of the
main shaft, coupled by means of rods or otherwise to the crank pin)
with suitable valves, gear, and connections, to enable it to act as an air
pump for the condenser, and when required as a steam cylinder and
piston for the purpose of obtaining virtually at the time of starting or
reversing the effect or convenience of a pair of engines without a dead
centre.
The above position of this cylinder refers only to vertical engines, but
in its application to other kinds the said combined "air pump and
pusher" is still placed at right angles or thereabouts to the main
cylinder with suitable valves and gears, which can be thrown in or out
of action for either duty. This arrangement is more particularly useful.
in marine engines to be used as a "pusher" or pair of engines when
entering or leaving port, and at other times as an air pump in the usual
manner.
The third part of this Invention consists in a novel and more complete
arrangement of apparatus than, has hitherto been used for stopping,
starting, reversing, and controlling "or handling" steam engines, of
such dimensions as cannot be "handled" by manual power alone. For
this purpose we employ as the motive power a steam cylinder and

page_text: piston with the necessary and convenient valve arrangement for
admitting steam to or exhausting from either side of piston, and in con-
nexion with these we employ either a second cylinder and piston or a
pair of plungers or." rams
"and suitable working barrels (which may
when desirable be considerably smaller in area than the steam cylinder
and piston before named), which through the medium of water, oil,
or other liquid shall check or control the speed and distance traversed
by these parts, and their effect upon the gear and valves of the engine
to which they are connected.
In some cases we prefer to dispense with the -before-named steam
cylinder, and to obtain both motive and controlling power or effect by-
means of the hydraulic cylinder only; the same being of larger diameter
and the exhaust water from this cylinder being delivered into the con-.
denser (as a supplementary injection), and thus the difference in
pressure between the atmosphere and the condenser is used in lieu of
any other artificial pressure as the motive power.
For the purpose of obtaining absolute control we employ a peculiar
arrangement of valves and gear or their equivalent in connection
with the liquid or controlling cylinders, so arranged that whilst
O the exit valves or apertures are contracted to a sufficient extent for
checking the speed or entirely closed for holding (as before explained),
the inlet valves for readmitting the liquid on the return stroke are of
more ample area in consideration of the difference of the pressure during
exit and return.
In some cases instead of using the double valve before named, we
obtain the same effect by the use of a single valve for both supply and
exhaust, the opening of this being performed either by the reversing
lever or the governor, and the closing being effected by the responding
motion of the piston and its connections.
For the sake of simplicity of arrangement and also of the working, all
the before-named valves or equivalents are connected with and actuated
by the starting or reversing lever. Thus by the employment of the
before-named apparatus, in which is embodied both the variable opening
and entire closing of the apparatus or passages for regulating the escape
of the liquid, perfect control is obtained by merely sufficient manual
power to work this small valve gear instead of the main gear of the
engine.
·

page_text: Secondly. The combined arrangement of air pump and steam pusher
to get over the dead centre.
Thirdly. The arrangement of auxiliary hydraulic controlling apparatus
for attaining ease and freedom of action, both for handling the engines
and governing automatically by expansion. .
In witness whereof, we, the said William Dawes and Henry Percy
Holt, have hereunto set our hands and seals, this Thirteenth
day of November, in the year of our Lord One thousand eight
hundred and seventy-four.
Witness,
JOHN HANDSLEY DALES,
Burley Street,
Leeds.
(L.S.)
WILLIAM DAWES.
HENRY PERCY HOLT. (L.S.)