IMPROVEMENTS IN STEAM ENGINES, STEAM BOILER AND OTHER FURNACES, AND IN APPARATUS FOR HEATING FEED WATER
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by William M°Naught at the
Office of the Commissioners of Patents, with his Petition, on
the 13th March 1868.
I, WILLIAM MCNAUGHT, of Rochdale, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN STEAM ENGINES, STEAM BOILER AND OTHER FURNACES, AND
IN APPARATUS FOR HEATING FEED WATER," to be as follows:-
Firstly. My improvements relate to an arrangement of fire-bars
which will allow a free admission of air to the fuel and facilitate the
escape of ashes, and they consist in making deep serrations in the
upper edges of the fire-bars arranged in their lengthways across the
furnace, their ends resting upon a pivot so that an oscillating movement
may be communicated to them by a lever and rod which connects
the whole series of them together, motion being communicated to the
lever by hand or by power.
Secondly. My improvements relate to an arrangement of fire-bars
in the lengthways of the furnace, the object of which is to feed the
fuel from the mouth or front of the furnace towards the bridge, and

page_text: my improvements consists in arranging the bars to slide or move
endways backward and forward, and in gearing them with levers,
cams, or tooth wheels so that all the bars will move forward together,
then a little afterwards each alternate bar will be drawn back and
then the remaining alternate bars will next be brought back,
these operations being slowly repeated in succession; the fuel carried
forward by the movement of the entire fire-bars is left to be again
carried forward by the next simultaneous movement of the bars, and
thus the "green" coal or fuel fed in front is slowly carried along, and
that nearest the bridge having become incandescent will consume
the smoke and gases passing over from the "green "fuel in front.
Combined with the above arrangement of fire-bars a "hopper" with a
hinged or sliding bottom is employed in the front of the furnace and
the fuel is filled into this "hopper," and then by opening or removing
its bottom it is allowed to fall upon the front of the fire-bars to be carried
forward as above described.
The mechanism above explained may be worked at intervals by hand
or by power.
Thirdly. My improvements relate to a hollow fire bridge and they
consist in making the bridge of such form that the gases will have
to pass under or through it. It is made of iron or fire-clay in one
or more pieces and has perforated holes or slits for the air to escape
from it downwards, and thus ashes cannot stop up the perforations;
and by this form and arrangement of bridge the bottoms or flues of
boilers are protected from the cooling effect of the air passing from
the bridge.
The admission of air to the bridge is regulated by a
valve or door actuated by hand or well known self-acting mechanism
or by connection with the engine.
Fourthly. My improvements relate to apparatus for heating feed
water by pipes arranged in the flues from the furnace and consist in
giving the up-and-down motion to the scrapers acting to remove the
soot from the heating pipes by means of a "mangled toothed wheel"
and pinion instead of the mechanism hitherto used. The movement
from the mangle wheel is conveyed to the scrapers by bevel wheels
and the usual chain pulleys and chains. This part of my improvements
also consists in forming the scrapers of flat plates their lower ends
resting upon an arm carried by the chains, the upper ends having
pieces cut out to fit the pipes when resting against them at an acute

page_text: angle thereto. By this arrangement the soot slides down the scrapers
and is prevented from accumulating upon them.
Fifthly. My improvements relate to a method of equalising the strains
acting upon engines working the steam expansively by which means
the expansive working of the steam may be carried to a greater extent
with increased economy, as engines having my improvements applied
will bear with safety a much greater pressure of steam at the beginning
of each stroke than engines as hitherto constructed. My improvements
consist in applying to steam engines a compensating wheel or weights
on arms made to oscillate by the engine, and arranged so that the
excess of the pressure of the steam at the beginning of the stroke
will be absorbed in overcoming the inertia of the mass of the com-
pensating wheel or weights, which will give back the momentum thus
obtained during the second half of the stroke, therefore the strains
upon the parts of the engine will be equalised, and the driving force
acting upon the crank and the consequent velocity will be nearly
uniform. The compensating wheel or arms with weights upon them is
mounted upon a shaft arranged so that the wheel or arms can oscillate,
and an arm upon this shaft is connected by a link or links with the
piston rod of the engine or the piston end of the beam in beam
engines.
Sixthly. My improvements relate to the valves of steam engines and
to means of cutting off the steam to the cylinders for expansive
working by self-acting mechanism. The slide valve is made as long
as it can be worked in a valve chest nearly the length of the cylinder
so as to shorten the "ports" as much as possible and is made hollow,
and the exhaust steam passes into the said valve and out at a long
slot into a similar slot on the interior face of the valve chest, which
slot leads to the exhaust branch; the steam is admitted to the cylinder
through ports at the end of such valve in the usual manner. Two
superimposed slides are worked upon the valve which are similar to
such as are in general use, but are capable of being shifted further from
or nearer to each other so as to vary the point at which the steam
is cut off; this is effected by connecting the said slides to the excentric
or cam which works them by means of two spindles, one of which is
hollow to allow the other to pass through it; these spindles are attached
to the slides, and at the other end of each is a right-hand thread
upon one and a left-hand thread upon the other. Screwed upon the

page_text: end of each spindle is a long bush with opposite threads, and by turning
the said bush round in one direction or the other the ends of the
said spindles will approach or recede from each other and with them
the slides. The outer spindle passes through the stuffing box of the
valve chest, the bush is made steam-tight upon it by means of an
elastic nut of india-rubber or other suitable composition, provision
being made for closing the same by means of a stuffing box on the
top of the bush when necessary and upon the inner spindle. The said
long bush is journaled in a cross bar properly guided by slides, this
cross bar is connected to the excentric rod and reciprocates with its
motion. Upon the said bush is either a worm wheel or a bevel wheel
suitably geared to a shaft journaled to the said cross bar, one of which
wheels has a square hole or sliding key to allow it to slide backwards
and forwards on a shaft which is connected by reversing wheels to
the governor in the usual manner, so that as this shaft turns in one
direction or the other by the action of the governor the said bush
does the same and the slides consequently approach or recede from
each other as required.
Seventhly. My improvements relate to piston and air pump buckets,
and are made upon those described in Specifications of one Patent
granted to myself Number 753, A.D. 1857, and of another Patent
granted to myself and another person Number 98, A.D. 1859. As
described in the Specifications of those Patents the flexibility of the
rings for pistons and buckets is produced by certain portions being
cut out of the interior flange of the ring with intervening portions
rigid. My present improvements consist in making the interior of
the said flange to a certain curvature without any rigid portions.
Another improvement applicable to the pistons above referred unto
consists in a provision for restoring the true position of the axis of
the piston rod when worn downwards, which happens in horizontal
and inclined cylinders, by means of packings, inserted on the under, side
betwixt the piston body and the rings which raise the body into its
true position, this may also be effected by means of screws.
Eighthly. My improvements relate to means for lubricating pistons,
valves, and other parts, and consists in driving the melted tallow or
lubricating matter from its closed receptacle to the parts to be
lubricated by forcing in water at the lower part of the receptacle by a
pump worked by the engine or occasionally by hand, and consequently

page_text: forcing out the lubricating matter through an orifice at the upper
part of the receptacle, the water thus injected being drawn off when
the tallow is all driven out of the receptacle, and by this means the
difficulties which are met with when pumping tallow or other lubri-
cating matter are overcome.