An Improved Spark Arrester.
Year: 1894

page_text: Date of Application, 2nd Jan., 1894
Complete Specification Left, 24th Sept., 1894--Accepted, 27th Oct., 1894
PROVISIONAL SPECIFICATION.
An Improved Spark Arrester.
I DAVID ANDERSON, of " Fairview," Stawell, in the Colony of Victoria,
Gentleman, do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved spark arrester that is applicable to
locomotive, portable or traction engines. It consists of a perforated vibrating
metallic cage of cylindrical or other form made preferably of copper and arranged
to enclose or surround the area between the top end of exhaust pipe and the bottom
of the funnel. The perforations in such copper cage are preferably circular as
close as practicable to one another and not more than one eighth of an inch
diameter.
The cage
is supported in position from crown of smoke box by two pivotal pins
one at each side, a close fitting joint being made thereat by the top edge of the cage
fitting over a flange projecting into it from top of smoke box, and the cage is
suspended by such pivots, so that it can move or shake freely in both directions
that is forward and backward and sidewise.
The bottom end of cage has a hole in it that is larger than the top end of exhaust
or blast pipe such hole being large enough to allow the cage to shake or vibrate to
the requisite extent.
To close the joint at bottom end of cage a flange is fitted on exhaust pipe such
flange being in two pieces and bolted together to allow of its being clamped at the
requisite position on exhaust pipe. One part of the side of cage is made in the
form of a door preferably hinged and furnished with a catch in order that it may
be readily opened and closed.
By the cage being hung or loosely supported as described when the engine is at
work or travelling the cage is caused to shake or vibrate, and in so doing its top
edges alternately strike against the crown of smoke box and such stroke or shock
imparted to the cage causes all soot and small particles of fuel to fall from its
perforations and surfaces and so the said perforations are kept open and clear and
consequently do not interfere with the draught.
Dated this 1st day of January 1894.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Applicant's Agent.
COMPLETE SPECIFICATION.
An Improved Spark Arrester.
1 DAVID ANDERSON of "Fairview" Stawell in the Colony of Victoria
Gentleman, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement :-
My invention relates to an improved spark arrester which is applicable to
locomotive, portable or traction engine boilers, and also to marine boilers of the
portable type. It consists of a vibrating perforated metallic cage of cylindrical,
elliptical or other form made preferably of copper and arranged to enclose or
surround the area between the top end of exhaust pipe, and the bottom of funnel
of chimney. The perforations in such copper cage are preferably circular and of
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page_text: a tapered or inwardly enlarged section and as close as practicable to one another
and not more than one eighth of an inch in diameter. The total combined area of
the perforations in the cage I prefer should be not less than three times that of the
sectional area of the funnel or chimney.
The cage is supported in position from crown of smoke box by two pivotal pins
which pass into oval or other shaped enlarged holes arranged one at each side of
the cage, a close fitting joint being made around top of cage by its top part or rim
fitting over a flange or ring projecting into it from top of smoke box and which
flange or ring usually supports the pivotal pins. The cage being thus suspended
by such pivots it can move or shake freely in both directions, that is forward and
backward and sidewise.
The bottom end of cage has a hole in it which is larger than the top end of
exhaust or blast pipe such hole being large enough to allow the cage to shake or
vibrate to the requisite extent. To close the joint at bottom of cage, a flange is
fitted on exhaust pipe such flange being in two pieces bolted together to allow of
its being clamped at the requisite position on said exhaust pipe. One part of the
side of cage is made in the form of a door preferably hinged and furnished with a
catch in order that it may be readily opened and closed. The purpose of the door
is to allow of its being opened to increase the draught when fire is being lit after
the boiler has been washed out and also to allow the inner wall of cage to be cleaned
and to give access to the blower and the nozzle of blast pipe.
By the cage being hung or loosely supported as described, when the engine is at
work or travelling the cage is caused to shake or vibrate, and in so doing its top or
end parts alternately strike against the crown of smoke box and the stroke or
shock thus imparted to the cage causes all soot and small particles of fuel to fall
from its perforations and surfaces and so the said perforations are kept open and
clear and consequently the draught area is not interfered with or reduced. By the
said holes or perforations being tapered or enlarged inwardly any particles of fuel
that may be inclined to stick or remain in any of the holes is withdrawn by the
draught.
In order that my invention may be well understood I will now describe it by
reference to the accompanying sheet of drawings, in which
Fig. 1, is a side elevation of my improved spark arrester as arranged in the smoke
box of a locomotive, portable or traction engine boiler.
Fig. 2, a plan looking down on top of the spark arrester, the crown of smoke box
being removed.
Fig. 3, a broken section on line a, a, of Fig. 1.
In all the figs. only a small portion of the sides and bottom of the cage is shewn
perforated although it must be understood that the whole surface as far as
practicable is perforated such perforations being preferably formed by punching.
A is the cage constructed preferably of copper plate of from No. 10 to No. 20
gauge. Its bottom plate is flanged and rivetted to the side as shewn at A' and it
has a centrally arranged hole A2 which is sufficiently large in diameter to allow the
cage to shake or vibrate without touching the blast or exhaust pipe B. The top
part or edge of cage is strengthened with a ring A3 which is rivetted to it and such
top part or edge fits freely over another and wider metal ring C which has four or
more lugs C formed on or attached to it to receive bolts for securing the ring up
to the crown plate C* of smoke box. The top edge of cage has an internal rim or
flange a' formed on it which fits neatly over ring C. It will be obvious that said
ring C can be arranged outside the cage A in place of inside it as shewn in the
drawings. C³ is the funnel or chimney. D are slot holes formed diametrically
opposite one another through the upper edge ring A³ of cage and through each of
said holes I pass a screw stud or bolt D¹ which is screwed into the inner ring C
and it is upon said two studs D' that the cage swings or shakes. As an alternative
the pins D may be screwed into the top ring of cage and pass through slot holes
in the ring Cor bolts or studs carrying the said pivotal pins may project down
from and be secured to the crown of smoke box. To close the annular space

page_text: between the hole A³ in bottom of cage and the blast or exhaust pipe B, I secure a
two part flange E upon the latter, said flange piece being bolted together and such
flange has its upper or horizontal part perforated as shewn at e, in Fig. 3. A is
the door of cage shewn hinged at A and furnished with a catch A. F is the
ordinary ring blower pipe arranged within the cage. Although I shew the
cage A made of an elliptic section I do not confine myself to such shape as I am
well aware that it can be made either of a circular or rectangular section and be
supported upon two bolts or pins such as D' in accordance with this invention.
Further I wish it understood that I do not confine myself to having the pivotal
bolts or pins D¹ arranged at the position indicated in the drawings, that is on the
conjugate diametrical line of the elliptic cage as I am aware that for some classes
of boilers the pins or pivots can be more conveniently arranged on the transverse
diametrical line of the ellipse, either position will serve the purpose of my invention
viz. to support the cage in a manner that it can vibrate or shake about when the
engine is in motion. If so desired the lower end of the cage may be attached to
a crank lever the shaft of which is capable of being worked to and fro by a handle
outside the smoke box, the object of such an attachment being to provide means for
the cage being shaken whilst the engine is standing.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A spark arrester consisting of a perforated metallic cage preferably copper
arranged to enclose or surround the area or space between the bottom of funnel
or chimney and top of blast pipe such cage being so hung or assembled in position
that it is capable of a vibrating or shaking motion substantially as herein
described.
2. In a spark arrester a perforated cage such as A in combination with a ring
such as C secured to crown of smoke box the cage being held at the desired
position on the ring by two pivotal pins or bolts such as D'arranged diametrically
opposite one another substantially as described and as illustrated in my drawings.
3. In a spark arrester the perforated cage such as A having a hole such as A³ at
its bottom in combination with the flange such as E secured on the blast pipe B
substantially as herein described and as illustrated in my drawings.
4. In a spark arrester a door such as A' arranged at the side of the perforated
metallic cage as and for the purposes described and as illustrated in my drawings.
5. In a spark arrester a perforated metallic cage A having a ring A³ at its top
and holes D therethrough and a hole A' through its bottom in combination with a
ring C into which bolts D' are screwed said ring being supported from crown of
smoke box or smoke chamber and with the flange E secured upon blast pipe all
arranged and assembled substantially as herein described and as illustrated in my
drawings.
Dated this 21st day of August 1894.
Dated this 21st day of August 1894.
D. ANDERSON.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C.