IMPROVEMENTS IN STEAM BOILERS
Year: 1864

page_text: LETTERS PATENT to William Husband, of Hayle, in the County of
Cornwall, and Joseph Quick, junior, of Sumner Street, Southwark, in
the County of Surrey, for the Invention of "IMPROVEMENTS IN STEAM
BOILERS."
Sealed the 26th May 1865, and dated the 7th December 1864.
PROVISIONAL SPECIFICATION left by the said William Husband and
Joseph Quick at the Office of the Commissioners of Patents, with their
Petition, on the 7th December 1864.
We, WILLIAM HUSBAND, of Hayle, in the County of Cornwall, and JOSEPH
QUICK, junior, of Sumner Street, Southwark, in the County of Surrey, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN STEAM
BOILERS," to be as follows:-
Our improvements have for their object the prevention of the explosion of
steam boilers; as also the strengthening of the same so as to prevent their
being put out of shape by excessive pressure. For preventing the explosion
of steam boilers, plugs of fusible metal have been fixed in them in order that
when, through want of water or from other causes, the boiler becomes heated
beyond a certain degree, rendering it unsafe, such plugs shall melt and shall
prevent an explosion from taking place, by allowing the water and steam to
escape into the fire, so as to extinguish it. Such plugs have however, frequently
proved unreliable on account of the pressure in the boiler sometimes attaining

page_text: a dangerous degree, without that part of the same in which the fusible plug
is situated, being heated to the requisite degree for the plug to melt.
Now one part of our Invention consists in connecting such fusible plugs or
discs to some part of the boiler independent of the part in which they are
fixed, so that when such last-named part is somewhat bent or bulged by
excessive pressure of steam in the boiler, the fusible plug, if not melted by
the heat, will become ruptured on account of the before-mentioned connection
not allowing it to move with the part that is bulged, and it will thus allow the
escape of water and steam from the boiler and prevent the explosion thereof,
not only when it becomes overheated to a dangerous degree, but also when
the pressure of the steam at all exceeds the limits which the boiler can bear
with safety.
The manner of effecting such connection of the fusible plug may be variously
modified; thus, it may be connected directly by a rod or bar to a part of the
boiler opposite to that in which it is fixed, or it may be connected to one end
of a double ended lever, the fulcrum of which is attached to another part of the
boiler, while the other end of the lever is fixed to the same part of the boiler
in which the fusible plug is fixed but at a point some distance off, so that if
this part is bulged at such a point it will by moving the lever still cause the
plug to be ruptured. We prefer, however, to insure the bending or bulging
of the boiler from excessive pressure at the particular point or points in which
the plug or plugs is or are fixed, by making the other parts of the boiler
stronger, by preference strengthening them by means of an arrangement to be
hereafter described.
Our Invention may also be carried into effect without of necessity making
the aforesaid plug of an easily fusible metal; thus it may be either made as a
disc of any more refractory metal and of such a thickness as to rupture readily
when acted upon in the above-described manner, or it may be made in the
form of a conical or other valve, which is only lifted off its seat by the before
described action.
Another part of our Invention consists in strengthening steam boilers, by
so attaching to the interior of the same bars or plates of metal of a any suitable
form, that these shall be firmly connected thereto, but shall not be in imme-
diate contact with the surface of the boiler to which they are connected, nor
have any considerable amount of their surface in contact with metallic
surfaces directly connected to the boiler, so that if from any cause such surface
of the boiler becomes over heated and thereby weakened the heat thereof
will not be readily communicated to the strengthening plate or bar, which
will thereby be prevented from being weakened in a similar manner.

page_text: In the arrangement which we prefer to employ two pieces of angle iron
are rivetted to the surface of the boiler with their projecting sides such a
distance apart that the web of a piece of T iron may be placed between them
and fixed thereto by means of rivets or bolts with washers, by preference of a
material that is a bad conductor of heat, intervening on either side between
the web of the T iron and the angle iron. The T iron or other form of the
strengthening bar or plate may also be attached directly to the surface of the
boiler, but prevented from coming in contact with the same by means of
washers, by preference of a substance that is a bad conductor of heat, being
interposed between the surface of the boiler and that of the bar or plate.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Husband and Joseph Quick in the Great Seal
Patent Office on the 6th June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
HUSBAND, of Hayle, in the County of Cornwall, and JOSEPH QUICK, junior, of
Sumner Street, Southwark, in the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Seventh day of December, in the year of our Lord,
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,.
the said William Husband and Joseph Quick, Her special licence that we,.
the said William Husband and Joseph Quick, our executors, administrators,
and assigns, or such others as we, the said William Husband and Joseph
Quick, junior, our executors, administrators, and assigns,, should at any time
agree with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS. IN STEAM BOILERS,"
upon the condition (amongst others) that we, the said William Husband and
Joseph Quick, junior, our executors or administrators, by an instrument in
writing under our or their hands and seals, or under the hand and seal of one
of us, or them, should particularly describe and ascertain the nature of the said
Iuvention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that 1, the said Joseph Quick, Junior, on Denait or my-
self and the said William Husband, do hereby declare the nature of the said
Invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement thereof, reference
being had to the accompanying Drawing, and to the figures and letters marked
thereon, that is to say :-
Our improvements have for their object the prevention of the explosion of
steam boilers, as also the strengthening of the same so as to prevent their
being put out of shape by excessive pressure. For preventing the explosion
of steam boilers plugs of fusible metal have been fixed in them, in order that.
when through want of water or from other causes, the boiler becomes heated
beyond a certain degree rendering it unsafe, such plugs shall melt, and shall
prevent an explosion from taking place by allowing the water and steam to
escape into the fire so as to extinguish it. Such plugs have however fre-
quently proved unreliable on account of the pressure in the boiler sometimes
attaining a dangerous degree without that part of the same in which the
fusible plug is situated being heated to the requisite degree for the plug to
melt, or owing to the fusible properties of the plug having become useless by
a hardened deposit over the same.
Now one part of our Invention consists in connecting such fusible plugs or
discs to some part of the boiler independent of the part in which they are
fixed, so that when such last-named part is somewhat bent or bulged by
excessive pressure of steam in the boiler, the fusible plug if not melted by the
heat will become ruptured on account of the before-mentioned connexion not
allowing it to move with the part that is bulged, and it will thus allow the escape
of water and steam from the boiler, and prevent the explosion thereof not only
when it becomes overheated to a dangerous degree, but also when the pressure
of the steam at all exceeds the limits which the boiler can bear with safety.
The manner of effecting such connexion of the fusible plug may be variously
modified; thus it may be connected directly by a rod or bar to a part of the
boiler opposite to that in which it is fixed, or it may be connected to one end
of a double-ended lever, the fulcrum of which is attached to another part of
the boiler in which the fusible plug is fixed, but at a point at some distance
off, so that if this part is bulged at such a point, it will by moving the lever
still cause the plug to be ruptured. We prefer, however, to insure the
bending or bulging of the boiler from excessive pressure at the particular
point or points in which the plug or plugs is or are fixed by making the other
parts of the boiler stronger, by preference strengthening them by means of an
arrangement to be hereafter described:

page_text: Our Invention may also be carried into effect without of necessity making
the aforesaid plug of an easily fusible metal, thus it may be either made of a
disc of any more refractory metal, and of such a thickness as to rupture readily
when acted upon in the above-described manner, or it may be made in the
form of a conical or other valve, which is only lifted off its seat by the before-.
described action.
Another part of our Invention consists in strengthening steam boilers by
so attaching to the interior of the same bars or plates of metal of any suitable
form that these shall be firmly connected thereto, but shall not be in imme-
diate contact with the surface of the boiler to which they are connected, nor
have any considerable amount of their surface in contact with metallic
surfaces directly connected to the boiler, so that if from any cause such surface
of the boiler becomes overheated, and thereby weakened, the heat thereof will
not be readily communicated to the strengthening plate or bar, which will
thereby be prevented from being weakened in a similar manner.
In the arrangement which we prefer to employ two pieces of angle iron are
rivetted to the surface, of the boiler, with their projecting sides such a distance
apart that the web of a piece of T-iron may be placed between them, and
fixed, thereto by means of rivets or bolts, with washers, by preference of a
material that is a bad conductor of heat, intervening on either side between.
the web of the T-iron and the angle iron. The T-iron or other form of the.
strengthening bar or plate may also be attached directly to the surface of the
boiler, but prevented from coming in contact with the same by means of
washers, by preference of a substance that is a bad conductor of heat, being
interposed between the surface of the boiler and that, of the bar or plate.
On the accompanying Drawing: are shown the arrangements we prefer to.
employ in carrying our Invention into practice. .
Figure 1 shews a part longitudinal section of a Cornish boiler A in the top
of the tube B, of which a fusible plug or disc C is fixed immediately over
the fire-grate D, the arrangement of which disc is shewn more clearly in the.
enlarged section at Figure 2. The disc C is held in the manner shewn in a
seat. E, and is connected by means of the rod F to the strap G, bolted to the.
top of the boiler, or the rod F may itself be fixed to the boiler shell.
By this arrangement it will be seen that if the pressure of steam in the
; boiler is such as.. to deflect the tube B without the disc C having been. pre-
viously melted, such disc not being able to sink with the tube on account of
its attachment to the top of the boiler will become ruptured, and either allow
the water to pass on to the fire so as to extinguish it, or relieve the pressure
in the boiler by allowing the steam to escape.,

page_text: Figure 3 shows a different mode of forming and fixing the fusible plug or
disc C. The fusible metal is attached to the rod F by means of an eye formed
in each, through which a bolt N passes, and in order to cause the disc to rup-
ture readily it is weakend round its inner circumference as shown, and is
supported by the seat E on its under surface, so as to withstand the down-
ward pressure of the steam upon it.
Figure 4 shews an arrangement by which the rupturing of the plug or disc
may be effected by the deflection of a part of the tube not immediately over
the fire. Here the rod F that holds the disc is attached to one end of a
double-ended lever H, suspended at I from the top of the boiler, the other
end of which lever is connected by a rod J to another part of the tube B.
From this arrangement it will be seen that if the part of the tube over the
fire is deflected, the rod F being still virtually connected to the top of the boiler
as in the previous arrangement, will cause the plug to be ruptured, whereas if
the tube is deflected at the point where the rod J is connected to it this rod
will draw down that end of the lever H, and consequently in raising the
other end will also cause the rod F to be drawn up, and will thus effect the
rupturing of the plug.
We prefer, however, as before stated, to insure the deflection of the tube
only taking place at the point where the fusible plug is fixed by making the
other part of the tube stronger. If requisite, two or more such before-described
plugs may be fixed in different parts of the boiler.
At Figure 1 is shown our before described improved mode of strengthening
the boiler. K is a ring of T-iron, which is not directly connected to the
tube B, but is rivetted to two rings of angle iron L, L, fixed to the boiler
tube, washers M, M, by preference of a material that is a bad conductor of
heat being placed between the T-iron and angle iron, so as to have the
smallest possible metallic connexion between them. By this means it will be
seen that though the tube B may become heated to such a degree as to be
considerably weakened, yet the T-iron ring K being but slightly in metallic
connexion with the same, and surrounded on all sides by water or steam, will
not become injuriously heated, and will therefore prevent the tube from
collapsing.
Another arrangement of this part of our Invention is shewn at K¹, where
the T-iron is rivetted directly to the boiler tube, having washers M' of a S
material that is a bad conductor of heat interposed between it and the tube.
Having now described the nature of our Invention, and in what manner
the same is to be performed, we wish it to be understood that we do
not limit ourselves to the precise arrangement of the same as herein-

page_text: before described with reference to the accompanying Drawing, as these may
be variously modified without departing from the nature of our Invention,
thus, as before stated, instead of a disc of fusible metal a thin disc of metal
that is not so readily fusible may be employed, or instead of a disc or plug a
conical or other valve may be used, although we prefer the arrangement
described. Nor do we limit ourselves to the combined employment of the two
parts of our Invention as shown at Figure 1, as each part may be employed
separately and independently of the other; but what we claim is,-
First, the employment of a plug, disc, or valve of fusible or other metal,
closing an opening situated over the fire-grate or other part of steam boilers,
and so connected to another part of the boiler that upon the deflection or
bulging out either of the part in which the plug, disc, or valve is fixed, or of
any other part to which it is connected, such connection will cause the plug,
disc, or valve to be ruptured or opened so as to allow of the escape of water
or steam.
Second, strengthening steam boilers by means of bars or rings of T-angle
or other shaped iron, so connected thereto that no part of the surface of such
bars or rings is in immediate contact with the surface of the boiler, nor has
any considerable metallic connection therewith.
Third, connecting strengthening bars or rings to the internal surface of
steam boilers in such a manner that washers or pieces of any suitable material
that is a bad conductor of heat are interposed between the surfaces of the
bars or rings, and either of the boiler itself, or of the angle or other iron fixed
thereto, to which the bars or rings are connected.
In witness whereof, I, the said Joseph Quick, junior, have hereunto set
my hand and seal, this Sixth day of June, in the year of our Lord
One thousand eight hundred and sixty-five.
JOSEPH QUICK, JUN. (L.S.)