IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1873

page_text: LETTERS PATENT to Thomas Common Brown, of Ipswich, in the
County of Suffolk, Mechanical Engineer, and George Arthur
Biddell, of Ipswich, aforesaid, Mechanical Engineer, for the
Invention of "IMPROVEMENTS IN STEAM ENGINES AND BOILERS."
Sealed the 3rd June 1873, and dated the 8th April 1873.
PROVISIONAL SPECIFICATION left by the said Thomas Common
Brown and George Arthur Biddell at the Office of the Com-
missioners of Patents, with their Petition, on the 8th April 1873.
We, THOMAS COMMON BROWN, of Ipswich, in the County of Suffolk,
Mechanical Engineer, and GEORGE ARTHUR BIDDELL, of Ipswich,
aforesaid, Mechanical Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN STEAM ENGINES AND BOILERS," to be as
follows:-

page_text: .
Firstly. In a new arrangement of mechanism for regulating the
admission of the steam to the cylinder, so as to cut off the supply at
any portion of the stroke of the piston within certain limits, and thus
work the steam with variable expansion, according to the load and
pressure.
Secondly. In attaching the cut-off apparatus direct to the governor or
to a steam or water pressure apparatus, which is under the control of
the governor, and which is supplied with steam or water direct from the
boiler, by which the motion of the engine is so regulated that nearly the
same number of strokes in a given time can be obtained whatever the
load may be or however the pressure of the load may vary, so long as
there is sufficient pressure to overcome the resistance of the load on the
engine.
Thirdly. In an improved revolving pendulum governor so arranged
as to preserve the engine at a nearly constant speed.
Fourthly. In an improved method of drying or superheating the
steam in the boiler before entering the cylinder.
Our improvements we carry into effect in the following manner :-On
the crank shaft of the engine we fix two eccentrics, one placed at such
an angle in relation to the crank as to effect an early, and the other a
late suppression of the steam. The outer ends of the rods attached to
the straps embracing these eccentrics we connect together by a link;
the middle part of the link between the ends of the eccentric rods is
embraced by and is capable of sliding through a block carried by the
slide valve rod, thus forming a cut-off apparatus.
being attached either to the cut-off valve or the main slide valve
according as the engine is fitted with or without a cut-off valve.
The slide valve rod
By a weigh shaft and suitable arms and rods we attach the cut-off
apparatus to the governor, so that the whole acts in the following
manner-When the load on the engine is diminished or increased the
governor instantly begins and continues to revolve above or below its
proper speed, until it shifts the link and brings the valve more or less
under the influence of the early or late cut-off eccentric, and so adjusts
the supply of steam to the altered load, and the engine again revolves at
its proper speed.

page_text: Instead of attaching the cut-off apparatus direct to the governor we
sometimes interpose between it and the governor a steam or water
pressure apparatus, which consists of a small cylinder with a piston
working in it tight under pressure, to the piston rod of which is attached
the cut-off apparatus. The governor in this case is attached to a lever
working a valve, which admits steam or water from the boiler to either
side of the piston in the small cylinder, which thus gives motion to it
and alters the position of the link and the supply of steam as required.
The object of using the steam or water pressure apparatus is to relieve
the governor of the work required to be done in varying the position of
the cut-off apparatus and to lessen the size of the governor.
Our improvements in governors consists in applying to the ordinary
revolving pendulum governor a bent lever, which revolves with the
governor, the horizontal arm of which rests upon its sliding collar, which
is raised or lowered by the balls, as the quicker or slower speed causes
them to revolve further from or nearer to the centre of motion. On the
other arm of the bent lever and in the centre of motion of the governor
we place a weight or a spring to oppose the centrifugal force of the
balls. This arm of the bent lever is placed at such an angle that
through its rapidly varying leverage as it is raised or lowered the
pressure of the weight or spring upon it will just balance the centrifugal
force of the balls in all positions when the governor revolves at a
constant speed.
Instead of placing the weight or spring in the centre of motion,
around which the balls revolve, we sometimes place it on an arm fixed
on a separate weigh shaft actuated by the governor. This arm is placed
at such an angle that the effect of the weight or spring upon it in all
positions will nearly balance the centrifugal force of the balls when
the governor and engine revolve at a constant speed. This arrangement
has the advantage of enabling the speed of the engine to be varied at
pleasure by altering the distance of the weight from the centre of the
weigh shaft.
The superheating apparatus consists of one or more metal tubes
leading from the fire-box or furnace of the boiler directly through the
steam space of the same, and into the smoke flue or chimney.
Portions of the heated gases from the fire pass through the tube or
tubes. We surround each of the hot tubes by another tube of thin

page_text: metal, leaving a small annular space between them, and arrange to pass
all or a portion only of the steam as it goes to the cylinder of the engine
through this annular space in contact with the hot tubes, and thus dry
or superheat the steam.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Common Brown and George Arthur
Biddell in the Great Seal Patent Office on the 7th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
COMMON BROWN, of Ipswich, in the County of Suffolk, Mechanical
Engineer, and GEORGE ARTHUR BIDDELL, of Ipswich, aforesaid,
Mechanical Engineer, send greeting.
WHEREAS
Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of April, 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 suc-
cessors, give and grant unto us, the said Thomas Common Brown and
George Arthur Biddell, Her special license that we, the said Thomas
Common Brown and George Arthur Biddell, our executors, adminis-
trators, and assigns, or such others as we, the said Thomas Common
Brown and George Arthur Biddell, 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 AND
BOILEBB," upon the condition (amongst others) that we, the said Thomas
Common Brown and George Arthur Biddell, our executors or adminis-
trators, by an instrument in writing under our or their hands and seals,
or under the hand and seal of one of us or them, 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 George Arthur Biddell, on behalf
of myself and the said Thomas Common Brown, do hereby declare the

page_text: nature of the said Invention, and in what manner the same is to be
performed to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
The object of our Invention is to economise fuel and to obtain constant
uniform motion in the speed of the engine.
Our Invention consists,-
Firstly. In a new arrangement of mechanism for regulating the
admission of the steam to the cylinder, so as to cut off the supply at
any portion of the stroke of the piston within certain limits, and thus
work the steam with variable expansion, according to the load and
pressure.
Secondly. In attaching the cut-off apparatus direct to the governor,
or to a steam or water pressure apparatus which is under the control of
the governor, and which is supplied with steam or water direct from the
boiler, by which the motion of the engine is so regulated that nearly the
same number of strokes in a given time can be obtained whatever the
load may be, or however the pressure of the load may vary, so long as
there is sufficient pressure to overcome the resistance of the load on the
engine.
Thirdly. In an improved revolving pendulum governor so arranged
as to preserve the engine at a nearly constant speed.
Fourthly. In an improved method of drying or superheating the steam
in the boiler before entering the cylinder.
Our improvements we carry into effect in the following manner:-On
the crank shaft of the engine we fix two eccentrics, one placed at such
an angle in relation to the crank as to effect an early, and the other a late
suppression of the steam. The outer ends of the rods attached to the
straps embracing these eccentrics we connect together by a link; the
middle part of the link between the ends of the eccentric rods is
embraced by, and is capable of, sliding through a block carried by the
slide valve rod, thus forming a cut-off apparatus. The slide valve rod
being attached either to the cut-off valve or the main slide valve,
according as the engine is fitted with or without a cut-off valve.
By a weigh shaft and suitable arms and rods we attach the cut-off
apparatus to the governor, so that the whole acts in the following
manner: -When the load on the engine is diminished or increased the

page_text: governor instantly begins and continues to revolve above or below its
proper speed until it shifts the link and brings the valve more or less
under the influence of the early or late cut-off eccentric, and so adjusts
the supply of steam to the altered load, and the engine again revolves at
its proper speed.
Instead of attaching the cut-off apparatus direct to the governor, we
sometimes interpose between it and the governor a steam or water
pressure apparatus, which consists of a small cylinder with a piston
working in it tight under pressure, to the piston rod of which is attached
the cut-off apparatus; the governor in this case is attached to a lever
working a valve, which admits steam or water from the boiler to either
side of the piston in a small cylinder, which thus gives motion to it and
alters the position of the link and the supply of steam as required.
The object of using the steam or water pressure apparatus is to relieve
the governor of the work required to be done in varying the position of
the cut-off apparatus, and to lessen the size of the governor.
Our improvements in governors consist in applying to the ordinary
revolving pendulum governor a bent lever, which revolves with the
governor, the horizontal arm of which rests upon its sliding collar, which
is raised or lowered by the balls, as the quicker or slower speed causes
them to revolve further from or nearer to the centre of motion; on the
other arm of the bent lever, and in the centre of motion of the governor,
we place a weight or a spring to oppose the centrifugal force of the
balls; this arm of the bent lever is placed at such an angle that through
its rapidly varying leverage, as it is raised or lowered, the pressure of
the weight or spring upon it will just balance the centrifugal force of
the balls in all positions when the governor revolves at a constant
speed.
Instead of placing the weight or spring in the centre of motion around
which the balls revolve, we sometimes place it on an arm fixed on a
separate weigh shaft actuated by the governor; this arm is placed at
such an angle that the effect of the weight or spring upon it in all
positions will nearly balance the centrifugal force of the balls when the
governor and engine revolve at a constant speed. This arrangement has
the advantage of enabling the speed of the engine to be varied at
pleasure by altering the distance of the weight from the centre of the
weigh shaft.

page_text: The superheating apparatus consists of one or more metal tubes
leading from the fire-box or furnace of the boiler directly through the
steam space of the same and into the smoke flue or chimney.
Portions of the heated gases from the fire pass through the tube or
tubes; we surround each of the hot tubes by another tube of thin metal,
leaving a small annular space between them, and arrange to pass all or a
portion only of the steam as it goes to the cylinder of the engine through
this annular space in contact with the hot tubes, and thus dry or super-
heat the steam.
In order that our said Invention may be most fully understood and
readily carried into effect, we will proceed to describe the Drawings
hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
On Sheet 1 Figure 1 is a plan; Figure 2, a side elevation; and
Figure 3, an end elevation of so much of a portable steam engine as will
suffice to shew the application of the first and second parts of our In-
vention to engines of this class when fitted with double slide valves.
a is the main slide eccentric; b and c are the two eccentrics for
moving the cut-off slide, the eccentric b being set at such an angle with
the crank as to cause the steam to be cut off at about half the stroke of
the piston. The eccentric c is set to cut off the steam very early in the
stroke, say, at about th. The eccentric rods b¹ and c' are connected
by the link d. The rod e (of the cut-off slide valve) has a box or
socket formed upon it for retaining the block in which the link d is
fitted to slide smoothly, thus forming a cut-off apparatus giving a vari-
able expansion within the limits mentioned. An ordinary governor A is
connected with the link d by means of the weigh shaft h, lever i, and
connecting rod 1. To the weigh shaft is fixed the arm m upon which
the weight n slides, and is adjustable radially, and may be fixed in any
position by the set screw o. The arm m is fixed upon the weigh shaft h
at such an angle with the horizontal that the varying horizontal leverage
of the weight as nearly as possible counteracts the variations of the
centrifugal force of the governor balls throughout their range at one
and the same speed of revolution. The dotted lines shew an inter-
mediate position of the link.
On Sheet II. Figure 1 is a plan; Figure 2, a side elevation; and
Figure 3, an end elevation of a modification, such of the parts shewn, as

page_text: above described, being indicated by similar letters. In this modification
instead of attaching the governor directly to the cut-off apparatus, the
lever is connected with the slide valve of a small steam or water
cylinder which is connected with the steam or water space of the
boiler by the pipe j; the pipe k is the escape pipe. The cylinder g has
a steam-tight piston, the rod of which is connected with one end of the
link d by the connecting rod 7. The governor A moves the slide valve,
and directs the pressure of the boiler above or below the piston of the
cylinder g, and thus raises or lowers the link d.
We prefer and apply this modification in cases where it is desirable
to have a very small and light governor, or where a very large slide
valve has to be moved, the arrangement shewn on Sheet I, being more
applicable to governors of considerable size and weight, on account of
the pressure on the collar due to the action of the counterweight n.
Sheet III. shews parts of our improvements in governors; Figures 1
and 2 are two views of a governor constructed according to our improve-
ments. a is the spindle having a projecting part, forming a fulcrum
at b for the levers c at each side of the spindle; the levers are attached
to the weight d by the links e, e, and have a projecting part so shaped
as to bear centrally upon the sliding collar f of the governor. The
weight d acting upon the collar f through the links e, and the varying
angle of the levers c will exactly counteract the varying centrifugal
force of the balls in all positions, the pressure upon the collar being
always proportionate to the lifting power of the balls.
Figures 3 and 4 shew a modification in which a spring g is employed
in place of the weight d, and in this case the spring is compressed.
Figures 5 and 6 shew an arrangement in which the spring is extended.
In both cases the levers c and links e are proportioned so as to com-
pensate for the increasing pressure in compressing or extending the
spring, and to cause the pressure upon the sliding collar of the governor
to be always proportionate to the lifting power of the balls.
Sheet IV. shews our improvements in drying and superheating
steam.
Figure 1 is a plan; Figure 2, a side elevation in section; Figure 3, an
end view in section; and Figure 4, a view of the smoke box end of parts
of a portable steam engine boiler. A is the fire-box: a and b are two

page_text: GEORGE ARTHUR BIDDELL. (L.B.)