CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1876

page_text: LETTERS PATENT to Edward James Coleman, of Hyde Park, in the County
of Norfolk, State of Massachusetts, United States of America, at present
residing at Brixton, in the County of Surrey, in England, for the Invention of
"CERTAIN IMPROVEMENTS IN STEAM ENGINES." A communication from abroad
by Hiram Stevens Maxim, of the City, County, and State of New York,
United States.
led the 5th January 1877, and dated the 10th July 1876.
PROVISIONAL SPECIFICATION left by the said Edward James Coleman at the
Office of the Commissioners of Patents on the 10th July 1876.
EDWARD JAMES COLEMAN, of Hyde Park, in the County of Norfolk, State of
Massachusetts, United States of America, at present residing at Brixton, in the
County of Surrey, in England. "CERTAIN IMPROVEMENTS IN STEAM ENGINES."
A communication from abroad by Hiram Stevens Maxim, of the City, County,
and State of New York, United States.
The object of this Invention is the construction of a steam engine and boiler
which shall be at once cheap to build, economical in fuel, automatic in its action,
casily operated, occupying but little space, and producing the highest attainable
results with so few and inexpensive parts that they may be applied not only to
large and expensive engines, but may also be applied to small and cheap engines.
The Invention consists of two parts, first, governor and cut-off'; and, second,
a peculiar arrangement or configuration of the cylinder steam chest, exhaust
steam jacket, and feed water heater.
The first part relates to the governor and cut-off which control the speed of
the engine, and belong to that class of governors that control the speed of the
engine by the length of time they allow the steam valve to remain open rather
than the distance that the said valve opens. When an engine having this governor
is running with but little load the steam is cut off early in the stroke. When
the load is increased then the steam follows farther and is cut off at a much later
period of the stroke.
"
It is a well-known fact in steam engineering that there is a great loss of power
in checking the steam before it enters the cylinder, as is the rule with all ordinary
governors, and to obviate this fault known as "wire drawing the steam many
attempts have been made, but the character of governors heretofore used that
[Price 6d.]

page_text: operated directly on the point of cut-off have been so very complicated, cumber-
some, and expensive as to preclude their use, except in very large engines, besides,
none of them have been suitable for quick running engines, therefore all small
engines have been compelled to use the old fashioned governor, which simply
throttles and renders inert a portion of the energy of the steam before it enters the
cylinder at all.
The object of this my present Invention is to make an automatic cut-off and
steam engine governor so simple, cheap, and reliable that it can be applied to the
less expensive class of engines, and at the same time produce the best attainable
results, and being placed within the belt, pulley, or wheel it necessitates no belt or
cog wheels to transmit motion to it.
This governor may be applied to any kind of engine equally well, but I will
illustrate it by detailing how it may be applied to oscillating engines. I use a
crank shaft, a belt, pulley, and weights or balls of governor, also two-armed lever,
which transmits motion from a cam to the valve; said cam has advancing faces
parallel to the axis of the shaft, and the receding terminations are cut spirally;
spiral springs are used which draw the weights together, and counteract their
centrifugal force. Arms are formed on part of the same casting as the weights, the
whole moving freely on pivots, and operating as a lever of the second order on the
cain, said cam having an adjustable follower. A piston is also attached to said
cam, fitted loosely to recess in the limb of pulley wheel, forming an air cushion
or controlling chamber to prevent a too sudden movement longitudinally of the
A balanced cut-off valve is also employed.
cam.
The operation of this automatic cut-off and governor is as follows:-Steam being
admitted at the valve chamber it passes upwards through valve and enters the
cylinder and gives motion to the engine. While the engine is still running slow
the steam will enter the cylinder with the full boiler pressure so long as the valve
remains open, and said valve will remain open only while the upper end of the
lever rests upon the projections of cam, which projections extend through degrees
sufficient to hold the valve open about three-fourths of the time occupied by the
piston making one forward and backward stroke. When the speed of the
engine has increased until the centrifugal force of the weights is more than equal
to the tension of the springs then said weights will be thrown outwards, and the
cam will be drawn back by the arms, thus bringing a shorter portion of the
projections under the lever, and allowing the valve to close at an earlier period of
the stroke. Any increase in the speed of the engine shortens the point of cut-off,
while a decrease lengthens it. The advancing faces of the said projections are
in line with the shaft, so that the sliding of the cam does not change the point
at which the steam is let into the cylinder, but the receding face is cut spirally
in such a manner that a slight change in the position of the cam changes the point
at which the lever falls back from the projection to the cylindrical portion of the
cam, and as the valve is only open during the time the lever is riding the projections
it is obvious that the closing of the valve and the consequent cutting off of the
steam depends only on the position of the cam in relation to the lever, and as the
position of said cam is controlled solely by the weights, and they again by the speed
of the engine, it will therefore be seen that the speed of the engine operates directly
and at once on the point of cut-off.
This device operates equally as well as a marine governor, as a very slightl
When a
increase of speed in the engine instantaneously closes off the steam.
governor only is required a cone can be substituted for the cam and accompanying
devices.
As an illustration of the second part of my Invention I take an engine of a
The
common slide valve type, and the operation of the governor is identical.
steam being cut off before it enters the steam chest, and a three-armed lever being
substituted for the two-armed lever of the oscillating engine. The third arm has
a spring attached, which causes the upper end of the lever to follow closely the
movements of the cam, thus closing the cut-off valve at the proper time.
"
The

page_text: tension of the spring may be adjusted by lock nuts. A chamber holding the
cut-off valve is used also with the safety valve, throttle valve, with usual cylinder,
and the exhaust steam jacket. An exhaust steam pipe is used with jet for inducing
draught; also supplementary exhaust for removing the water of condensation by
heating feed, thereby giving dry steam for the jet. A pipe conveys feed water from
heater to water leg of boiler.
The operation is as follows:-Water being supplied to the boiler, and a fire
started on the grate, the products of combustion pass upwards through tubes in
a space, and then downwards through larger tubes, imparting heat to the water,
and escaping through the smoke pipe.
Steam being generated of a sufficient pressure, and. the throttle valve being
opened, the steam will enter the pipe, and after passing through the cut-off and
slide valve will enter the cylinder very nearly the full boiler pressure. When the
speed of the engine has attained a point where the centrifugal force of the revolving
weights in the fly wheel is more than equal to the tension of the two springs, the
said weights will fly outward, and thus draw the cam back, presenting a shorter
projection under the adjustable follower, and thus cut the steam off at an earlier
point of the stroke, as before described. The exhaust steam, escaping in the usual
way, enters the annulus around the cylinder and steam chest, and this keeps them
at about the right temperature.
I am aware that some makers of steam engines have placed the cylinder directly
in the boiler, but this is objectionable, from the fact that the cylinder will be
somewhat hotter than the expanding steam, thus preventing the deposition of
water on the inside of the cylinder; this leads to dryness, and consequent rapid
wear and abrasions, besides the difference of temperature between the steam in the
boiler and the mean temperature of the steam in the cylinder is quite equal to the
difference between the exhaust steam and expanding steam of the cylinder, there-
fore the loss in either case is about equal.
In one case condensation is produced in the boiler with no beneficial results what-
ever, while in the other case what little condensation occurs acts as a lubricant in
exactly the right spot.
About the steam jacket is a water space encased by a strong casing. Into this
space the cold feed water is pumped, where it soon attains a higher temperature,
and enters the boiler through a suitable pipe. One of the exhaust pipes extends
to near the bottom of the jacket; this should be provided with a suitable stop-
cock or valve that may be opened or closed at will, but never entirely closed.
About one-sixth of all the steam is condensed in the jacket, and may be drawn off
as water from this pipe. Should it be desirable at any time to cause a strong
draught, then this cock may be nearly closed, only being opened enough to allow
the condensation to escape, then the remaining five-sixths of the steam will escape
through the pipe before mentioned and its jet, and thus produce the well-known
effect in the smoke pipe. Thus it will be seen that by my Invention the feed
water may be heated, and at the same time plenty of dry steam is available to
blow the fire.
Very much trouble has occurred in the use of engines placed directly on top
of the boiler from the overheating of the parts, the whole top of the boiler is
exposed, and of a temperature due to the high pressure of steam; this has often
ruined belts, and caused governors operated by belts to become inoperative,
endangering life and property, besides wasting much heat and rendering the sur-
rounding air oppressively hot. This is obviated in my Invention by placing the
feed water heater between the boiler and engine. Thus an engine very compact
in form, very reliable in action, very economical in use, very cheaply and strongly
constructed, and of great beauty, is produced suitable for amateurs and manufac-
turers when a small and reliable power is required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Edward James Coleman in the Great Seal Patent Office on 10th January
1877.
EDWARD JAMES COLEMAN, of Hyde Park, in the County of Norfolk, State of
Massachusetts, United States of America, but at present residing at Brixton, in the
County of Surrey, in England. "CERTAIN IMPROVEMENTS IN STEAM ENGINES." A
communication from abroad by Hiram Stevens Maxim, of the City, County, and
State of New York, United States.
The object of my Invention is the construction of a steam engine and boiler which
shall be at one cheap to build, economical in fuel, automatic in its action, easily
operated, occupying but little space, and producing the highest attainable results,
with so few and inexpensive parts that they may be applied not only to large
and expensive engines, but may also be applied to small and cheap engines.
My Invention consists of two parts, first, governor and cut-off; and, second, a
peculiar arrangement or configuration of the cylinder, steam chest, exhaust steam
jacket, and feed water heater.
The first part relates to the governor and cut-off which control the speed of the
engine, and belongs to that class of governor that controls the speed of the engine
by the length of time they allow the steam valve to remain open rather than
the distance that said valve opens. When an engine having this governor is
running with but little load the steam is cut off early in the stroke. When the
load is increased, then the steam follows farther and is cut off at a much later
period of the stroke. It is a well-known fact in in steam engineering that there is a
great loss of power in checking the steam before it enters the cylinder, as is the
rule with all ordinary governors, and to obviate this fault, known as "wire drawing
the steam," many attempts have been made, but the character of governors hereto-
fore used, that operated directly on the point of cut-off, have been so very complicated,
cumbersome, and expensive, as to preclude their use except on very large engines,
besides, none of them have been suitable for quick running engines, therefore all
small engines have been compelled to use the old fashioned governor which simply
throttles and renders inert a portion of the energy of the steam before it enters the
cylinder at all.
The object of this my present Invention is to make an automatic cut-off and
steam engine governor so simple, cheap, and reliable that it can be applied to the
less expensive class of engines, at the same time produce the best attainable results,
and being placed within the belt pulley or wheel it necessitates no belt or cog
wheel to transmit motion to it.
This governor may be applied to any kind of an engine equally well. I have
shown it as applied to oscillating engines in Sheet No. 1, Fig. 1 being a side
elevation exhibiting the belt pulley with the governor weights contained therein,
Fig. 2 is a vertical central section.
Fig. 3 is a perpendicular section, showing the vibrating lever, revolving cam, and
the cut-off valve in motion.
Fig. 4 represents a plan of the revolving spiral cam.
Description as applied to oscillating engines. Similar letters refer to similar parts.
A, A, crank shaft; 'B, B, belt pulley; C, C, weights or balls of governor; D, two
armed lever which transmits motion from cam F to valve L; E, governor valve
chamber; F, cam with advancing faces parallel to the axis of the shaft, and the
receding terminations cut spiral; G, G, spiral springs which draw the weights C, C,
together and counteract their centrifugal force; H, H, arms forming a part of the
same casting as the weights C, C, the whole moving freely on pivots d, d, and
operating as a lever of the second order on cam F; J, adjustable follower of cam F;
K, piston attached to cam F, and fitted closely to recess in the hub of pulley wheel
forming an air cushion or controlling chamber to prevent a too sudden movement
longitudinally of the cam F; L, balanced cut-off valve.

page_text: The operation of this automatic cut-off and governor is as follows:-Steam being
admitted at the valve chamber E in the direction of the arrows it passes upward
through valve L, enters the cylinder, and gives motion to the engine. While the
engine is still running slow the steam will enter the cylinder with the full boiler
pressure so long as the valve L remains open, and said valve will remain open only
while the upper end J of the lever D rests upon the projections M, M, of cam F,
which projection extends through degrees sufficient to hold the valve open about
three-fourths of the time occupied by the piston making one forward and back
stroke. When the speed of the engine has increased until the centrifugal force of
the weights C, C, is more than equal to the tension of the springs G, G, then said
weights will be thrown outward, and the cam F will be drawn back by the
arins H, H, thus bringing a shorter portion of the projections M, M, under the
lever D, and allowing the valve L to close at an earlier period of the stroke. Any
increase in the speed of the engine shortens the point of cut-off, while a decrease
lengthens it. The advancing faces of the projections M, M, are in line with the
shaft so that the sliding of the cam F does not change the point at which the steam
is let into the cylinder, but the receding face is cut spiral in such a manner that a
slight change in the position of the cain F changes the point at which the lever D
falls back from the projection M, M, to the cylindrical portion of the cain F, and
as the valve L is only open during the time the lever is riding the projections it is
obvious that the closing of the valve, and the consequent cutting-off of the steam
depends only on the position of cam F in relation to the lever D, and as the position
of said cam is controlled solely by the weights C, C, and they again by the speed of
the engine, it will therefore be seen that the speed of the engine operates directly
and at once on the point of cut-off.
This device operates equally as well as a marine governor, as a very slight in-
crease of speed in the engine instantaneously closes off the steam. When a governor
only is required a cone can be substituted for the cam F and accompanying devices.
Description of Sheet No. 2.-Fig. 5 is a vertical central section of a portion of
my Invention cut through X, Y. Fig. 6 is a vertical central section through V, W.
Fig. 7 is a horizontal section of the boiler and smoke pipe.
Fig. 8 is a side elevation exhibiting the fly wheel side of the engine.
Fig. 9 is a plan of the feed-water heater and boiler.
The engine shown in the above Figures (vizt., 5, 6, 7, 8, and 9) is that of a common
slide valve type, and the operation of the governor is identical. The steam being
cut off before it enters the steam chest, and the three-armed lever e being sub-
stituted for the two-armed lever of oscillating engine. The third arm has a spring f
attached which causes the upper end of the lever to follow closely the movements
of the cam, thus closing the cut-off valve at the proper time; the tension of the
spring may be adjusted by the lock nuts g. M is the chamber holding the cut-off
valve; N, the safety valve; O, the throttle valve; P, the cylinder; Q, the exhaust
steam jacket; R, exhaust steam pipe with jet for inducing draft; S, supple-
mentary exhaust for removing the water of condensation by heating feed, thereby
giving dry steam for the jet; T, pipe conveying feed water from heater to water
leg of boiler; u, stem of cut-off valve; 1, feed puinp.
The operation is as follows:-Water being supplied to the boiler, and a fire
started on the grate, the products of combustion pass upward through the tubes
,,, to the space V, V, and then downward through the larger tubes J, J, im-
parting its heat to the water and escaping through the smoke pipe K, as shown by
the arrows.
Steam being generated of a sufficient pressure, and the throttle valve O being
opened, the steam will enter pipe 7, and after passing through the cut-off and slide
valve will enter the cylinder very nearly the full boiler pressure. When the speed
of the engine has attained a point when the centrifugal force of the revolving
weights S, S, in the fly wheel is more than equal to the tension of the two
springs X, X, the said weights will fly outward, and thus draw the cam back, pre-
senting a shorter projection under the adjustable follower, and thus cut the steam
off at an earlier point of stroke, as before described. The exhaust steam escaping

page_text: in the usual way enters the annulus around the cylinder and steam chest, and this
keeps them at about the right temperature.
I am aware that some makers of steam engines have placed the cylinder directly
in the boiler, but this is objectionable, from the fact that the cylinder will be some-
what hotter than the expanding steam, thus preventing the deposition of water
'on the inside of the cylinder. This leads to dryness and consequent rapid wear
and abrasions, besides the difference of temperature between the steam in the
boiler, and the mean temperature of the steam in the cylinder is quite equal to the
difference between the exhaust steam and the expanding steam of the cylinder,
therefore the loss in either case are about equal.
In one case condensation is produced in the boiler with no beneficial results
whatever, while in the other case what little condensation occurs acts as a lubri-
cant in exactly the right spot.
About the steam jacket is a water space, encased by the strong casing m, m, into
this space the cold feed water is pumped, where it soon attains a high temperature
and enters the boiler through pipe T. I have shown two exhaust pipes leading
from the exhaust jacket, one of them S extends to near the, bottom of the jacket,
this should be provided with a suitable stop-cock or valve, that may be opened or
closed at will, but never entirely closed. About one-sixth of all the steam is con-
Should it be
densed in the jacket and may be drawn off as water from this pipe.
desirable at any time to cause a strong draft then this cock may be nearly closed,
only being opened enough to allow the condensation to escape, then the remaining
five-sixths of the steam will escape through the pipe R and its jet, and thus
produce the well-known effect in the smoke pipe. Thus it will be seen by
my Invention the feed water may be heated, and at the same time plenty of dry
steam available to blow the fire.
Very much trouble has occurred in the use of engines placed directly on top of
the boiler from the overheating of the parts, the whole top of the boiler exposed,
and of a temperature due to the high pressure of steam; this has often ruined belts
and caused governors operated by belts to become inoperative, endangering life
and property, besides wasting much heat and rendering the surrounding air oppres-
sively hot. This is obviated in my Invention by placing the feed water heater
between the boiler and engine.
Thus an engine very compact in form, very reliable in action, very economical in
use, very cheaply and strongly constructed, and of great beauty is produced suitable
for amateurs and manufacturers where a small and reliable power is required.
Having now particularly described and ascertained the nature and object of the
said Invention, and in what manner the same is to be performed or carried out in
practice I hereby declare that I claim-
1st. The sliding cam F, when provided with one or more projections, having
spiral terminations, said cain moving longitudinally on the main shaft, allowing
the cut-off valve in engines to close more or less early in its stroke, as said cam
is moved longitudinally, in the manner herein-before set forth and described.
2nd. The combination, of the crank shaft A, belt pulley B, springs G, G, weights
Ć, C, two and three-armed levers D, piston K, and balanced cut-off valve L, when
operating, as shewn and specified, in connection with a cam having spiral termina-
tions to its projections for the purpose specified.
3rd. Feed water heater m, exhaust steam space Q, exhaust steam pipes S and R,
and casting, provided with the safety valve N, throttle valve O, and steam pipe
7, substantially as shewn and described.
In witness whereof, I, the said Edward James Coleman, have hereunto set
my hand and seal, this Ninth day of January, in the year of our Lord One
thousand eight hundred and seventy-seven.
EDWARD J. COLEMAN, (L.S.)