CERTAIN IMPROVEMENTS IN STEAM ENGINES, AND IN THE WORKING OF STEAM BOLLERS OR GENERATORS, AND IN APPARATUS CONNECTED THEREWITH
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
AULD, of the City of Glasgow, North Britain, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Nineteenth day of
December, in the fourteenth year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said David Auld, Her especial
licence, full power, sole privilege and authority, that I, the said David Auld,
my exors, admors, and assigns, and such others as I, the said David Auld, my
exors, admors, 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,
Wales, and the Town of Berwick upon Tweed, my Invention of "CERTAIN
IMPROVEMENTS IN STEAM ENGINES, AND IN THE WORKING OF STEAM BOLLERS OR
GENERATORS, AND IN APPARATUS CONNECTED THEREWITH;" in which said Letters
Patent is contained a proviso, requiring that I, the said David Auld, by an
instrument in writing under my hand and seal, shall particularly describe and
ascertain the nature of my said Invention, and in what manner the same is
to be performed, and shall cause the same to be inrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
David Auld, do hereby declare the nature of my. Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by this present instrument in writing as follows, reference being
had to the Drawings hereunto attached, and to the letters and figures marked
thereon, that is to say:-
My said Invention relates, first, to various novel arrangements of mechanism,
apparatus, or means to be employed in connection with steam engines and
steam machinery for supplying steam boilers with water, and for the economic
regulation of such supply, and for the regulation or adjustment of the dampers
or flue valves of boilers. Second, to certain arrangements of mechanism,
apparatus, or means for the self-acting reduction or regulation of the steam
pressure in boilers, whereby low pressure steam may be drawn off from a boiler
or boilers working at a higher pressure, so that high and low pressure engines
may be worked or actuated from one boiler. Third, to a peculiar form or
arrangement of furnaces, flues, and apparatus connected therewith for the
purpose of economising the consumption of fuel, increasing the generation of
steam, and preventing the formation of smoke. Fourth, to a system or mode
of actuating or working the expansion valves of steam engines in connection
with a governor, wherein the action of the valves is regulated or adjusted by
the governor, through the intervention of a steam cylinder and piston, or other
apparatus of a like nature or effect. And in order that my said Invention may
be readily understood, I shall now proceed to describe the various Figures on
the Sheets of Drawings hereunto attached. Figure 1 on Sheet 1 of my
Drawings is a front or end elevation of a portion of a range of steam boilers,
in which two boilers only are delineated fitted with my self-acting water feeding
or supplying apparatus. The boilers and steam pipes therefrom are repre-
sented in complete external elevation, whilst the feeding apparatus is in vertical
section. A, A, are the two boilers working in connection, and supplying steam
to the engine by the main pipe B passing overhead. The feed water is supplied
to the boilers by the smaller pipe C running along their front ends, and having
branches and stop-cocks D, D, to each boiler, and also a branch at E leading
into the bottom of the steam and water chest F. This chest is placed upon
the brickwork of the boiler seating at such a level that the water contained in
it may correspond with the working water level in the boilers. Its upper or
steam portion is connected by the short branch G with the main steam pipe B
of the boilers, and the steam pressure thus directed to the top of the chest
consequently balances that due from the water pipe branch E at the bottom;
therefore the water level in the entire range of boilers at all times coincides

page_text: with that in the chest. The water supply is in this arrangement brought by
the pump. H from the reservoir I through the suction or lift pipe J, and forced
through the 'valve and branch K to the chest of the equilibrium or double-beat
valve L, situated at the bend of the pipe. In the chest F is contained a regulating
float M, fast on a vertical spindle passing out through a stuffing box in the top
of the chest, and through the external guide N of the pillar bracket O bolted
to the cover of the chest. This float spindle is connected by a slot at P with
one end of the double lever vibrating on a stud centre carried by the pillar O.
The opposite end of this lever is similarly connected at R with the spindle of
the equilibrium valve L, which passes through the top of the valve chest, and
is guided at S by the opposite arm of the pillar O. When the water level in
the boilers is at the proper working height, as delineated in my Drawings, the
float M, acting through the lever Q, keeps the 'equilibrium valve L closed, so
as to prevent the admission of the water from the pump H to the boiler, the
water supply so brought being allowed to flow off through the loaded valve T
and escape. When, however, the water level falls in the boilers, the corre-
sponding fall in the chest Flowers the float M, and through its movement
opens the valve L to admit water from the pump H through the valve into the
pipe C. In this way the water so applied is fed into all the boilers alike until
the attainment of the proper working level causes the float M to be again
elevated in the chest F, closing the valve L, and stopping the further supply.
It is obvious that by this arrangement any number of boilers placed on the
same level and working in connection, may have their feed water regulated by
a single apparatus of the kind which I have described; the feed pipe from the
regulating apparatus being passed in a true horizontal: line along the range of
boilers. Figure 2 on Sheet 1 of my Drawings represents another arrangement
for the regulation of the water supply of steam boilers, wherein the proper
adjustment of the feed water is obtained from a float in the boiler acting upon
a valve in the suction or lift pipe of the feed pump. This Figure represents
an end or transverse section of a single boiler, with the regulating float and
connections with the feed pump and cistern; but before describing this modi-
fication I shall refer to the portion of the Figure drawn in dotted lines in expla-
nation of a modification of the arrangement already delineated in reference to
Figure 1. The object of this latter modification is to enable the plan, Figure 1,
to be worked without involving the necessity of using a loaded valve, as at T
in Figure 1; for the discharge of the superfluous water. The dotted portion in
Figure 2 explains how this may be accomplished. A is the pipe leading from
the feed pump B to the boiler C, but represented as broken away in the Figure.
Instead of causing the feed water to pass through an equilibrium valve, as at

page_text: Lin Figure 1, the water way is left uninterrupted from the pump to the boiler,
except by the clack valve D opening towards the boiler. The equilibrium
valve as at E, its chest being set on a short branch on the upper side of the
pipe A, and its action is just the reverse of that described in reference to the
same detail in Figure 1. Its spindle F passes upwards through the top of the
chest, and is connected to a float contained either in the interior of the boiler
or in a steam and water chest in connection therewith, the float action being
such that when the water level falls, the valve E shall be closed. Similarly
when the water in the boiler rises above or up to the proper working level the
valve E is opened. The effect of this arrangement is, that so long as the valve E
. is closed, owing to the water being too low in the boiler, the feed supplied along
the pipe A having no other escape overcomes the steam pressure on the clack D
and passes into the boiler. So soon, however, as the water level arrives at its
proper height the action of the float opens the valve E, and the feed water
from the pipe A thus finding an easier mode of escape passes up through the
valve, and flows off by the outlet branch G, instead of overcoming the pressure
on the clack D, and by it entering the boiler. The remaining portion of
Figure 2, as drawn in sharp lines, exhibits a system of regulating the supply
of feed water a valve in the suction pipe of the pump. The regulating
float H is in this case placed within the boiler, its guide spindle passing upwards
through a stuffing box in the top of the boiler, and through the guide I in the
curved top of the pillar J bolted to the boiler. The float spindle is connected
at K with one end of a double lever L turning on a fixed centre at M in the
pillar J. The opposite lever arm is connected by a link N to a bell crank O,
carried on a fixed centre at P. The lower arm of the bell crank is again con-
nected by a rod Q, with the lever of a valve or stop-cock R in the suction or
lift-pipe S of the feed pump. The obvious effect of this arrangement is, that
as the regulating float H rises or falls with the varying water level in the
boiler, its action affects the valve R, correspondingly admitting more or less
water to pass up to the pump through the pipe S. By another plan, instead
of placing the valve R upon the suction pipe itself, it may be placed upon a
branch opening to the external atmosphere. In this way, when less or no
water is needed, the opening of the valve on this branch will admit air to vitiate
or destroy the action of the pump. Or by another modification the valve R
may be placed on a branch pipe communicating directly with the pump barrel,
so that the opening of the valve will admit a quantity of air or water to the
pump between the inlet and outlet clacks, accordingly as the branch is made
to open into the atmosphere or into water. In either case the admission
of the air or water will affect the action of the pump, so as to cause it to deliver

page_text: more or less water as may be required; with such an arrangement the pump
communicates directly with the boiler through the clack T.
Although in
Figure 2 I have represented a single boiler only as fitted with these several
plans of feed apparatus, it will yet be evident to practical men that a single
float may be made to answer for an entire range of boilers by placing it in a
detached steam and water chest in connection with series of boilers by a hori-
zontal feed pipe, as delineated in Figure 1.
Figure 1 on Sheet 2 of my Drawings represents another form of improved feed
apparatus for steam boilers, wherein the ordinary elevated feed pipe as applied
to low pressure boilers in existing arrangements is used. In this arrangement
a single feed pipe answers for the regulation of the water supply of any number
of boilers in a range, and admits of the combined action of the entire series
upon a single regulating float for actuating the damper. In this Figure is
delineated a set of three boilers A, A, A, a range connected by their overhead
main steam pipe B, and having a continuous horizontal feed pipe C traversing
along their front ends. The three boilers are represented in external elevation,
whilst the whole of the feed apparatus is in vertical section. The vertical feed
pipe, the ascent or descent of the water column in which regulates the damper
of the boiler flues, is at D, its lower end opening at E into the horizontal
pipe C. In this way the vertical pipe D is in communication with the entire
range of boilers, any variations in the steam pressure in which causes a corre-
sponding variation in the height of the water column, thus raising or lowering
the balanced float F and adjusting the damper accordingly, so that each individual
boiler exercises its own due effect upon the damper in combination with the rest
of the series. The supply of water through the vertical pipe D is adjusted by
the steam and water chamber G, which has a branch steam pipe H. opening
into the main pipe B, whilst its lower end is in connection with the horizontal
feed water pipe C by the branch at I. In my Drawings I have represented
the working water level of the boilers by dotted lines at J, J, J, and as the
pressure of the steam in the upper portion of the chest G balances the pressure
arising from the water in the lower portion, the water stands at the same level
in the chest as in the series of boilers. Then as this level varies, the rise or fall
of the float K in the chest acts through the rod L upon the lever M, which is
carried on a fixed centre N on the top of the small receiver O, surmounting the
vertical pipe D. The opposite arm of this lever is linked at P to a small
conical valve Q in the seat of the receiver, so that as the water level falls in
the chest G the descent of the float elevates the valve Q and admits water from
the receiver to the vertical pipe D for the supply of the boilers through the
pipe C. In the Drawing the water supply is supposed to be delivered to the

page_text: receiver Oby the branch R, whilst the surplus flows off by the opposite branch S.
It will be obvious to the practical man that instead of the steam, and water
chamber G a regulating float may be placed in one or more of the boilers, and
arranged to act upon the valve Q. In Figure 2.on Sheet 2 of my Drawings I
have delineated an arrangement which I adopt for the purpose of obtaining or
drawing off low pressure steam from a high pressure boiler. In this Figure a
boiler is represented in transverse or end section, with the adjusting apparatus
for the steam pressure. partly in vertical section. A is the boiler, which I shall
suppose to be working at a pressure very considerably higher than that at which
it is intended to draw off steam for another purpose. The main steam pipe for
constructing the ordinary high pressure steam to. the engine or machinery is
at B, the flow being governed by a stop valve C. At the opposite side of the
chest in which the stop valve is contained is a smaller steam pipe D, governed
by a sluice valve E, and extended onwards as at F. At G is a steam and water
chamber, from the top of. which a branch steam pipe H opens into the exten-
sion of the steam pipe F through the chest I of a loaded valve set on the upper
side of the pipe F. The lower part of the chest G is occupied by water, into
which the open lower end of a vertical pipe J is made to dip after passing through
the cover of the chamber. The steam from the pipe F, passing through the
valve chest I and branch H, presses upon the surface of the water in the
chamber G, and elevates a water column in the pipe J to a height corresponding
to the steam pressure. In the pipe J is a float K, a chain from which passes
over the fixed guide pulley Land descends to the segmental lever M, to which
it is attached. This lever M is fast on the spindle of the steam regulating valve N,
placed in the pipe F, immediately behind the valve E. The effect of this
arrangement is, that steam from the high pressure boiler passing along the
pipe D, F, elevates the loaded valve in the chest I, and entering the chamber G,
elevates a water column, in the pipe J, and with it the float K, producing a
partial closing of the valve N in the steam pipe D, F, and thus reduces the
steam pressure in the extension of the pipe F, whence it may be drawn off
In putting an apparatus of this class into action, the valve in the chest I
is loaded with a weight somewhat less than that necessary to keep the valve
closed against the pressure of the required low pressure steam; and the slight
elevation of the column of water in the pipe J, produced by the escape of steam
through this valve, then actuates the regulating valve N, adjusting the thorough-
fare for the passage of the high pressure steam through it to bring down the
pressure in the pipe beyond this valve to the point required. Thus whilst the
steam pressure on the side of the valve N next the boiler remains at its initial
height, that on the other side of the valve in the extension of the. pipe F is
for use.

page_text: reduced accordingly as this valve N is set to give a large or small thoroughfare
with a given height of water column in the pipe J. It is obvious that the
weight upon the loaded valve in the chest I may be any weight less than that
which would entirely prevent any escape of the steam through the valve, the
office of this valve being simply to allow as much steam to pass as will elevate
a short column of water in the pipe J, the actual regulation of the low pressure
discharge being effected entirely by the setting of the valve N. Thus, in
practice, it will be found that the weight per square inch upon the loaded valve
must be slightly less than the pressure at which it is desired to draw off low
pressure steam from the pipe F. By slight modifications of this arrangement
the vertical pipe J and water column, as well as the loaded valve of the chest I,
may all be dispensed with. According to one of these plans, a small steam
cylinder, with a piston, may be fitted upon the low pressure steam pipe, such
piston being weighted or held down by a spring and made to work in connection
with the regulating valve N. By this mode the rise or fall of the piston will
correspondingly affect the regulating valve, and open it only so far as to admit
steam to pass at the reduced pressure required. Or instead of this arrange-
ment of cylinder and piston, a chest may be fitted upon the low pressure steam
pipe F, and having within it a weighted disc or diaphragm of some elastic
material. The under side of this elastic diaphragm being open to the steam
pressure beneath, the material will be expanded or pressed upwards in a degree
corresponding with the actual pressure exerted. The movement of the diaphragm
thus produced may be communicated to the regulating valve N by a rod or
plunger on the upper side of the disc, so as to open or close the valve as may
be necessary for the desired low pressure. I may here remark that this power
of withdrawing steam from a boiler at any given variable pressure may be turned
to considerable advantage in various manufacturing processes where several
pressures may be required. Or the same system may be adopted in working
steam engines or machinery, so that one engine or machine may be worked by
a high pressure and another by a low pressure from the same boiler. Figure 3
on Sheet 2 of my Drawings represents a longitudinal section of my improved
furnace or fire-place and fluc, with the hopper or receiver for supplying the
fuel. Figure 4 on the same Sheet is a plan or horizontal section of the same.
The fuel is supplied by the receiver A, in the bottom of which is a sliding door
B to regulate the fall of coals through into the furnace, as at C. All the fuel
is supplied by this system, so that it is unnecessary to open the doors D at the
front of the furnace. The requisite supplies of coal are from time to time
pushed forward from the heap C by the rods or scrapers E, E. In the centre
of the flue, behind the grate bars, is placed a division of brickwork or other

page_text: material F, having expanded wings or curved sides G, G, on the end furthest
from the grate bars. As the gaseous current passes off from the grate, these
curved sides cause it to diverge outwards in two separate divisions, as indicated
by the arrows, and immediately after passing these surfaces the currents so
diverted come in contact with the second curved surfaces H, H, set against the
sides of the flue. The action of these curved or inclined surfaces is such that
the gascous particles are more effectually intermingled with each other, and
produce more perfect combustion, than is obtained by the ordinary form of flue.
The same system of reacting or intermingling curved or inclined surfaces may
be carried out to a still greater extent if necessary by placing a second or a
third series at intervals along the flue; or, by another modification, the upper
side or edge of the bridge I may be curved or inclined to produce the same
effect in connection with corresponding side surfaces, having the same reference
to the bridge as the surfaces H, H, bear to G, G. In working a series or range
of boilers in connection, I also propose to effect the better combustion of the
gaseous products of the furnaces by arranging the flues in such manner that
the gases shall pass through or in contact with the incandescent fuel or
flame in a furnace or flue previous to entering the chimney. In this way
the combined current of unconsumed gasés passing from the several fur-
naces is finally consumed instead of being permitted to escape wastefully;
or, in a single boiler with two or more fires in it, the unconsumed gases
from one or more of such fires may be passed through or in contact with
the flame or heated matter of one of the others previous to escaping from
beneath the boiler. Figure 5, on Sheet 2 of my Drawings, represents a side
elevation of a portion of a steam engine, to which improved mechanism and
arrangements for working the valves is attached. Figure 6, on the same
Sheet, is a corresponding plan of the same parts. In these views a portion of
the steam cylinder is delineated at A, having the ordinary nozzles B, B, attached.
The steam is supplied by the pipe C, where a common throttle valve D is
fitted, being worked from the upper ring E of the governor. In this arrange-
ment the nozzles contain four conical lift valves, one for the admission, and
one for the exhaust action of the steam, at each end of the cylinder. The
positions of these four valves are represented by the circles in the plan,
Figure 5, the whole set being worked from the two horizontal revolving
shafts F, G, each of which carries two cams H, I, and J, K, for this purpose.
The two cams I and K work the exhaust valves for the top and bottom of
the cylinder respectively. These are subject to no alteration, as they are set
to retain their valves constantly open throughout the respective exhaust
strokes. The other two cams H and J are constructed with their eccentric

page_text: prominences, set spirally in reference to their shafts; or, in other terms, they
resemble flat wedges wound upon a cylinder, so that by traversing them longitu-
dinally upon their shafts, they are caused to keep their valves open for a longer or
shorter time according to the motion given to them. Each cam is adjusted upon a
fixed feather in its shaft, so that it may traverse longitudinally whilst it is carried
round on the shaft. The spindles of the two steam admission valves are.
at L, M. That for the upper valve marked.L is linked to a lever oscillating
on a fixed centre at N, the opposite end of the lever being connected to the link
rod O, passing downwards to the actuating cam H, and having at its lower end
an open frame piece P, in which the cam works in giving motion to the valve.
The spindle M of the lower steam admission valve has its frame Q, for the
cam formed upon it, and passes directly from the cam to the valve. As the
cams revolve, their eccentric sides acting against the anti-friction pulleys R, R,
in the upper sides of their frames lift the valves for the admission of steam to
the cylinder, the valves falling down by their own weight to close the ports
when released from the cam action; or they may be drawn back in the
manner represented at S, where each cam frame has a projecting spindle,
having attached to it a small piston working in a water cylinder, the action of
the apparatus being very similar to that of the "cataract" as employed in
pumping, and well understood by practical men. The requisite longitudinal
movement of the cams for varying the duration of the opening of the valves
and, consequently, the degree of expansion, is obtained from the small hori-
zontal steam cylinder T, the action of which again is regulated by the governor's
lower sliding ring U. This ring is connected by the shafts and links V, W,
with the steam admission valve X, at the bottom of the cylinder T, so that as
the ring slides up or down from any variations in the speed of the engine, it
actuates the valve X, and admits steam to one or other end of the cylinder
accordingly as it may be set. Or instead of using steam to move the piston,
the cylinder may be connected with the condenser, so as to take advantage of the
atmospheric pressure to shift the cams. The piston rod Y of the cylinder has
upon its end a short cross-head Z, attached by a pair of collars to ring grooves
in the ends of the cams H and J. In this way, when a variation in the rate
of the engine causes steam to be admitted behind or beneath the piston of the
cylinder T, the consequent traverse of the piston causes a corresponding traverse
of the cams for the alteration of the degree of expansion in the manner which
I have already described. By this arrangement, the rate of the engine is
made through the medium of the governor to be the means of accurately
regulating the amount of expansion, whilst the employment of the actuating
steam cylinder for the traverse of the cams affords a varying action much

page_text: quicker and more certain and effective than that attainable by ordinary modes
now in use.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or restrict myself
to the precise details or arrangements which I have had occasion to describe
or refer to, as many variations may be made therefrom without deviating from
the principles or main features of my Invention, but what I consider to be
novel and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent is,--
First, the system or mode of regulating or adjusting the water supply of
steam boilers by means of a steam and water chamber and float in connection
with an adjustable valve on the feed water supply pipe, as herein-before
described.
Second, the system or mode of supplying water to a range or series of steam
boilers working in connection by a single regulating apparatus communicating
with a continuous horizontal water pipe.
Third, the system or mode of regulating the water supply by means of an
adjustable valve arranged to permit the surplus water to pass through it when
the feed is cut off from the boilers.
Fourth, the system or mode of regulating the water supply by means of an
adjustable valve placed on the lift or suction pipe of the feed pump, or by a
valve arranged to vitiate the action of the pump or supplying apparatus as
herein-before described.
Fifth, the system or mode of working or adjusting the dampers or flue valves
of a series or range of boilers by a single regulating apparatus, as herein-before
described.
Sixth, the application and use of a steam and water chamber and regulating
float, or of a float working in one boiler to an overhead feed pipe, for the
supply of a range of boilers.
Seventh, the system or mode of obtaining or drawing off steam at a lower
pressure than that contained in the supplying boiler, by means of a valve placed
in or working in connection with the low pressure steam pipe, branch, or receiver,
for the regulation of the action of the supply valve as herein-before described.
Eighth, the application and use of a valve placed in or working in connec-
tion with the low pressure pipe for the regulation of the low pressure supply as
herein-before described.
Ninth, the system or mode of regulating or adjusting the low pressure steam
supply by the action obtained from the low-pressure steam pipe.

page_text: Tenth, the application and use of a steam and water chamber in connection
with the adjustable valve for the regulation of the low-pressure steam, as herein-
before described.
Eleventh, the system or mode of regulating the low-pressure steam valve or
apparatus by means of a water column, as herein-before described.
Twelfth, the use and employment of a valve or regulating apparatus loaded
to a pressure lower than that of the low-pressure steam, as herein-before
described.
Thirteenth, the system or mode of supplying furnaces, with fuel by means of
a receiver worked in connection with a fuel adjusting apparatus, as herein-
before described. . .
Fourteenth, the system or mode of placing the fuel on the grate bars of
furnaces by means of a rod or feeding instrument passed through the front or
door of the furnace.
Fifteenth, the system or mode of fitting up boilers and furnaces with
separating and combining surfaces for the better combustion of the gaseous
products of the fuel, as herein-before described.
Sixteenth, the system or mode of working steam boiler furnaces, by causing
the combined gaseous products from one or more furnaces to pass through or
in contact with the incandescent fuel or flame in a furnace or flue before
entering the chimney or discharging flue.
Seventeenth, the system or mode of actuating or regulating the expansion
valves of steam engines by means of a steam or vacuum cylinder, as herein-
before described.
Eighteenth, the application and use of direct steam or vacuum pressure for
actuating or regulating the expansion valves of steam engines.
Nineteenth, the system or mode of regulating the rate of motion of steam
engines, or the degree of expansion of the steam, by means of the governor
working in connection with the steam or vacuum valve of an actuating appa-
ratus, as herein-before described.
In witness whereof, I, the said David Auld, have hereunto set my
hand and seal, the Seventeenth day of June, in the year of our Lord
One thousand eight hundred and fifty-one.

page_text: AND BE IT REMEMBERED, that on the Seventeenth day of June, in
the year of our Lord 1851, the aforesaid David Auld came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and everything therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Nineteenth day of June, in the year of our Lord One
thousand eight hundred and fifty-one.