Year: 1887

page_text: I, ALEXANDER WINTON ROBERTSON, of Custom House Engine Works, Victoria
Docks, West Ham, in the County of Essex, Engineer, 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, that is to say :-
My invention relates to improvements in the construction of furnace doors, whereby
the manufacture of same is much simplified, the cost much lessened, a perfect com-
bustion of fuel and consumption of smoke obtained, and, from the case with which
the door is operated, increased facility for supplying the furnace with fuel is gained.
These my improved furnace doors do not become choked up with ashes, dust, &c.
and no special attention on the part of the fireman or attendant is required. They
are particularly adapted for marine boilers, an element of great difficulty and even of
danger to the attendant in all fire doors hitherto constructed has been the liability of
such doors being caused to swing by the rolling of the vessel, which liability of
accident is from the construction and arrangement of my fire door entirely obviated.
And in order that my invention may be fully understood reference is had to the
accompanying drawings, and to the letters of reference marked thereon; Figure 1
being a front elevation of the door, Figure 2 a plan, and Figure 3 an end view of
same.
I construct my improved fire door of a sheet of metal A, preferably steel, pierced
as requisite with apertures a for the admission of air necessary for the proper combus-
tion of the fuel, one edge A' of which metal sheet A is turned over, as particularly
shewn in end view Figure 3, so as to envelope and carry a pin or axle B. The ends
of this pin B work in hearings C formed by the bending over of the extremities of
the angle iron D bolted or fixed to the furnace front, and against this angle iron D
the door rests when closed. A stiffening plate E it is found desirable to place around
the door A, and a flame or baffle plate F is carried by the sheet of metal A, and
supported by distance studs or pins f, particularly shewn in Figure 3. This flame or
battle plate may also be pierced with apertures g for the proper admission of air to the
furnace.
A convenient, and in my opinion the preferable, manner of attaching this door to
the furnace is to hinge same at the bottom, as shewn in the drawings, a pawl G

page_text: pivotted between the lugs H H, and furnished with counterbalance weight G¹ serving
to hold the door in its closed position.
To open the door the fireman or attendant strikes up the pawl G with his shovel, or
otherwise, and the door swings downwards, and opens. To close same he places his
shovel, rake, or other implement under the lug K, formed conveniently of a piece of
angle iron, attached to front A, and lifts the door up, and pushes it into its closed
position.
To facilitate the action of the door I make use of spring or springs attached in
any suitable manner to the hinges of the door, and Figures 4. 6. 8. 10. and 12
represent front elevations of doors fitted with various kinds of spring; and Figures 5.
7. 9. 11. and 13 represent end elevations of the same. Similar letters of reference
refer to like parts in these figures as in the Figures 1, 2, and 3, above described,
while the springs are here designated by the letter L.
Figures 4 and 5 shew a spring consisting of a strip of metal fixed at one end to
the hinge pin B, and coiled so as to take against front of furnace in such manner that
upon lowering the door the spring is compressed, and thus the fall of the door, when
being opened, is cased.
Figures 6 and 7 show a coil spring fitted around the ends of hinge pin B, and
having loose end to take against furnace front.
Figures 8 and 9 illustrate another form of spring, one end of which is attached to
hinge pin B in a similar manner to that shewn in Figures 4 and 5, but having its
other end attached to furnace front.
Figures 10 and 11 shew another form of coil spring fitted around hinge pin B with
one end taking against the furnace door A; and Figs. 12 and 13 illustrate a spring
consisting of a strip of metal, one end of which is attached to door A, the strip then
being curved round inside hinge, and having a loose end which is pressed against
upon the door being opened, and thus the fall is eased.
The above described figures illustrate various kinds of springs which may con-
veniently be employed to facilitate the action of the door, and to ease its fall, but I
do not limit myself to the shape and form of spring so described, as springs of other
types may be employed.
Furnace doors constructed and arranged in the manner above described possess
great strength and rigidity, and are of a much lighter weight (and consequently more
easily manipulated) than fire doors of ordinary construction.
They are less liable to sustain damage, and are more durable than any doors hitherto
constructed; and at the same time are adapted for boilers of every description, land
and marine.
Having now particularly described and ascertained the nature of this invention, and
in what manner the same is to be performed, I declare that what I claim is :-
1. In furnace doors, the construction of hinge formed by bending over the edge of
front plate A so as to envelope and carry a pin or axle B, the ends of which work in
the bearings C, substantially as set forth.
2. The application of springs L to the hinges of furnace doors, substantially as, and
for the purposes, hereinbefore set forth.
3. The general construction, arrangement, and combination of parts forming my
improvements in the construction of furnace doors, substantially as and for the
purposes hereinbefore set forth, and described with reference to the accompanying
drawings.
Tinted thin orth
عمل
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