IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Edward Ellis Allen at the Office
of the Commissioners of Patents, with his Petition, on the 16th March
1867.
I, EDWARD ELLIS ALLEN, of 40, Parliament Street, in the County of Mid-
dlesex, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN STEAM ENGINES AND BOILERS," to be as follows:-
Firstly, to increase the cylinder capacity of locomotive, traction, and other
steam engines in cases where the diameters of such cylinders are limited, as by
the frame plates of narrow gauge inside cylinder engines. This I do by
placing two cylinders in line with each other, and connecting the pistons and
valves so that they can be worked by the same rods and gearing.
Secondly, in communicating the motion of an ordinary locomotive driving
axle to a second axle for driving a second set of wheels fixed independently of
the first set. This I do by making a third crank on the first axle, and by
means of a connecting rod give motion to the second axle, which has a crank
in its centre. This mode of communicating motion from one axle to another
by a central rod allows of the two sets of driving wheels being separately
attached to the engine frames or boiler, so as to allow of the engine travelling
upon curves, which outside connecting rods will not admit of.
Thirdly, in a simple mode of driving traction engines at two different
speeds, by means of a pinion working in a wheel having internal and external
gearing, the said pinion being held between the two sets of teeth, and geared

page_text: with one or the other as required; the shaft upon which such pinion is keyed or
fixed being raised or lowered by suitable gearing having a radial motion from
the cross head as a centre.
Fourthly, in placing a plate on the inside of the driving wheels of traction
engines, so as to exclude dirt and protect the teeth upon them. This guard
plate remains stationary, the driving axle revolving through a boss in its
centre, the crank shaft passing through an opening made in the said guard
plate, and thus preventing its rotation on the driving axis.
Fifthly, in constructing the pitch wheels or pinions of traction engines
driven by pitch chains, so that their diameters may be increased as the chains
elongate. This I do by making each pitch tooth separate, and dropping it
into a recess formed in the pitch wheel. By means of small hard wood blocks
or packing pieces of thin metal plates the said pitch teeth may be dropped
more or less into their respective recesses, and so practically lessen or increase
the diameter of the pitch wheels or pinions.
Sixth, in constructing the wheels of traction engines or appliances in con-
nection therewith, so as to prevent their readily sinking in soft ground. This
I do in two different ways, first, by forming about two-thirds of the wheels
flat-sided, the other third being retained in a circular form for travelling on
the road. I prefer making the flat-sided portion of the wheels with six or
eight sides, and instead of one wide polygon two narrow ones may be placed
side by side, the angles of one being placed opposite the centres of the sides
of the other, or the road portion of the wheel may be in the centre, the
polygonal portion of the wheel being formed on each side. In applying this
form of wheel to ordinary wheels I form segments of the required shape, and
attach them to the circumference of the wheels. The second mode of con-
struction consists in forming an endless band, which is placed round each
driving wheel, and which the said wheel carries with it. This band I form of
wood or metal shoes, so formed and connected together that several of the
said shoes lie on the ground at the same time, and mostly in advance of the
driving wheel. I connect the several shoes by means of an endless band of
steel let into or otherwise fastened to each shoe, or the several shoes may be
connected by hinge joints; such joints, however, I prefer to form in sides or
flanges attached to the several shoes, which flanges also serve to keep the
endless band in place upon the wheel. The shoes are slipped or notched into
each other, so that they form a continuous bed or 'bearing for the wheel, or
they may be made separate and form a rigid bearing for the wheel by pro-
jecting pieces fixed on the circumference of the wheel, and which fit in
between the said shoes as the wheel revolves. The shoes may also be made

page_text: of plain wood or metal plates arranged so as to overlap each other, being
respectively jointed or attached at or about their centre lines.
Seventh, in arrangements for feeding portable engine and other boilers by
mechanical means. In the ease of new boilers I form a long narrow opening
in the front of the fire-box above the grate bars and through the water space,
and place a hopper in front of boiler communicating with the said opening.
In front of this opening I place a feeding roller consisting of a central spindle,
round which are fixed or cast radiating blades, which form cavities or troughs
into which the fuel in the hopper falls, and from which it escapes as the roller
revolves, thus gradually charging the grate bars with fuel at regular intervals
as required. The feed roller may either be driven by a band, cord, or chain,
direct from the crank shaft, or by a worm shaft and wheels. The axis of the
feed roller if placed within the fire-box is passed through the water space
through a hollow stay. In fitting the above apparatus to existing boilers I
make the hopper fit the ordinary fire-door, and place a second hopper or spout
inside the fire-box with the feed roller at the bottom, such inside hopper
gradually widening from the fire-door to the full width of grate.
Eighth, in the construction of a superheater at the end of the shell of a.
portable or locomotive boiler, this being formed either by the introduction of
a third tube plate separating the steam from the water space, or by a separate
casing made to fit into the shell of boiler, and having tubes corresponding
with those in the boiler itself, allowing of the latter being readily cleaned.
Ninth, in constructing the furnaces of portable engine and other similar
boilers so that the grate surface may be reduced in relation to the area of tho
tube plate, this object being usually accomplished by the use of fire-bricks
covering a portion of the grate area. I form the fire-boxes either by
gradually inclining them inwards towards the grate bars, keeping the water
spaces parallel, or nearly so; or I enlarge the water spaces at the level of the
grate bars, by bringing the sides of the fire-box inwards, and thus narrowing
the grate.
Tenth, in the construction of portable engine and other boilers of similar
character with vertical tubes instead of horizontal ones, such tubes being
arranged so that the whole of them can be readily removed, and also that the.
spaces between them for the passage of the flame shall gradually diminish
towards the funnel, this being accomplished either by varying the sizes of the
tubes, or by placing them nearer together as they approach the smoke box.
Eleventh, in the construction of boilers as above described; as also boilers
of large diameter known as Cornish boilers, with flues or tubes below the
furnaces or stacks of tubes, such flues or tubes being primarily intended to

page_text: reduce the capacity of the water spaces, but which may occasionally be used
as flues for the passage of the products of combustion.
Twelfth, in the construction of the smoke boxes of engines worked very
expansively, and in which case only a weak blast can be obtained, so that its
capacity may be reduced to the greatest extent. To this end I incline the
smoke box door so that the length of the said smoke box be only a few inches
at the bottom, but as wide at the top as required by the funnel. In applying
this principle to existing engines I form a box or case, which may be con-
veniently attached to the smoke box door, so as to fill up the space, and thus
reduce the capacity of the smoke box. This box or casing I propose in some
cases to employ as a water heater, but in this case I prefer not to attach it to
the smoke box door, and to fit it with tubes corresponding to those in boiler;
this arrangement is also well suited to act as a superheater, proper con-
nections being made for the ingress and egress of the steam.
Cases of the
kind here described may be made vertical either at the front or back, and
inclined on the opposite side, the widest part being at the bottom where the
smoke box requires to be narrowest.
Thirteenth, in the construction of apparatus for reducing the area or "vent"
through the tubes of boilers. This has been done by thick ferrules inserted in
the ends of the said tubes, but such ferrules diminish the opening by reducing
the diameter. Instead of this I make a round disc or washer of cast or plate
iron about two-thirds the area of the tube opening, and rivet it to a strip of
steel or hoop iron, which is easily bent so as to enter the tube, thus leaving
an annular opening of the required area. These discs may be readily with-
drawn, being held in place by the spring of the strip on which the discs are
fitted, and are very cheaply made. The discs and strips may be made in one
piece if preferred, or welded together.
When
Fourteenth, in the construction of the grates of portable engine boilers,
so as to increase or diminish the area of openings between the furnace bars.
This accomplish in three ways, first, by arranging the bars so as to lie
parallel with the centre line of the boiler, or inclined to the same, the
inclined position being readily given to them by moving one of the bearer
bars upon which they rest, or both bearer bars in opposite directions.
the said furnace bars are parallel to centre line of boiler the spaces between
them will be widest, and the more they are inclined the narrower will they
become. This arrangement is peculiarly applicable where an engine is
required to work at different powers, and where economy of fuel is desired.
The second method of accomplishing the same end is by having a second set
of bars placed below the first or main set, and tapered in the opposite direction,

page_text: that is, being made thin at top and wide at bottom. This second set of bars.
upon being raised or lowered will diminish or increase the air spaces between
the upper or fixed set of bars. The third mode of regulating the air spaces
is that of making the grate bars deep and rectangular in section, and so
arranging them that when placed vertically they present the widest openings,
but when inclined these openings are diminished. In this arrangement I
prefer to round the upper edges of the bars, so that when they were inclined
no sharp angles would be presented to the action of the fuel. Both in this
and the first arrangement described covering plates or similar contrivances
must be made to fill up the spaces left by the bars when in their inclined
position.