IMPROVEMENTS IN BOILERS OR STEAM GENERATORS, AND IN VALVES OR PLUGS CONNECTED THEREWITH
Year: 1867

page_text: LETTERS PATENT to Thomas Cowburn, of the Safety Valve Works,
Manchester, in the County of Lancaster, Engineer, for the Invention
of "IMPROVEMENTS IN BOILERS OR STEAM GENERATORS, AND IN VALVES OR
PLUGS CONNECTED THEREWITH."
Sealed the 13th September 1867, and dated the 16th March 1867.
PROVISIONAL SPECIFICATION left by the said Thomas Cowburn at the
Office of the Commissioners of Patents, with his Petition, on the
16th March 1867.
I, THOMAS COWBURN, of the Safety Valve Works, Manchester, in the County
of Lancaster, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN BOILERS OR STEAM GENERATORS, AND IN VALVES OR PLUGS
CONNECTED THEREWITH," to be as follows:-
My Invention relates principally to "safety valves" and "fusible valves"
or "plugs" to be fitted to steam boilers or water heaters for ordinary and
well understood purposes, and consists in so far as relates to "safety valves'
in the substitution of hollow metal weights for the solid metal weights employed
to load the valve, known as "Cowburns," and for which Letters Patent were
granted to me, bearing date the Thirteenth day of June, in the year One thousand
eight hundred and fifty-six. The said weights are cast or formed with a cell
or cells to contain metallic ores, sand, pulverized slag, lead, metal turnings or
borings, or any substance or material of sufficient gravity to constitute the
requisite load to the valve when added to the metal weight or weights.

page_text: In my improved "fusible valve" the plugs of "fusible metal
plugs of "fusible metal" are suitably
formed for driving or otherwise fixing into the ends of tubes of copper, brass,
or other suitable metal, a plug being driven into one end of each tube; these
tubes may be inserted and suitably fastened in holes made in the crown of the
furnace of the boiler or heater, or in any other ordinary or suitable position,
or may be fitted into a "fixing" bolted or otherwise fastened to the boiler in
the desired position. The tubes may be employed either separately or in sets
of two or more, as required, the upper part of each tube containing the plug
projecting into the water or other liquid, and the lower end projecting into or
towards the furnace. In order to admit of the fusible plugs being renewed
without having to enter the boiler I sometimes carry the upper part of the tube,
or a tube attached thereto, through the steam space to the outside of the boiler
and into a box attached to the shell of the boiler; and fitted with a cap capable
of being readily removed to obtain access to the interior of the tube. The
tube is tapered at the lower part or made smaller in bore at the part required
to be occupied by the plug, so that the plug of fusible metal may be dropped
into the tube and driven into position, or the tube may be readily withdrawn
for the purpose.
For the greater security of water heaters and "circulation" boilers I in
some cases attach thereto a pipe of comparatively large diameter, which may
be fitted with branches for the service of the hot water if required. In a
circulation boiler this will contain the upward current, the down current
passing through smaller pipes or tubes contained inside the larger pipe,
whereby the current of water entering the boiler is divided into several streams
and heated to some extent while passing through the smaller tubes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Cowburn in the Great Seal Patent Office on the
16th September 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
COWBURN, of the Safety Valve Works, Manchester, in the County of Lancaster,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of March, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Cowburn, Her special license that I, the said Thomas Cowburn,

page_text: my executors, administrators, and assigns, or such others as I, the said
Thomas Cowburn, my 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
BOILERS OR STEAM GENERATORS, AND IN VALVES AND PLUGS CONNECTED THEREWITH,"
upon the condition, amongst others, that I, the said Thomas Cowburn,
by an instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, 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.
NOW KNOW YE, that I, the said Thomas Cowburn, do hereby. declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement and accompanying Drawings (that is to say) :-
"
My Invention relates principally to "safety valves" and "fusible valves
or "plugs to be fitted to steam boilers or water heaters for ordinary and well
understood purposes, and consists in so far as relates to "safety valves" in
substitution of hollow metal weights for the solid metal weights employed to
load the valve known as "Cowburns," and for which Letters Patent were
granted to me bearing date the Thirteenth day of June, in the year One
thousand eight hundred and fifty-six. The said weights are cast or formed
with a cell or cells to contain metallic ores, sand, pulverized slag, lead, metal
turnings or borings, or any substance or material of sufficient gravity to
constitute the requisite load to the valve when added to the metal weights or
weight.
In my improved "fusible valve" the plugs of "fusible metal" are suitably
formed for driving or otherwise fixing into the ends of tubes of copper,
brass, or other suitable metal, a plug being driven into one end of each tube.;
these tubes may be inserted and suitably fastened in holes made in the crown
of the boiler or heater, or in any other ordinary or suitable position, or may
be fitted into a "fixing" bolted or otherwise fastened to the boiler in the
desired position. The tubes may be employed either separately or in sets
of two or more, as required, the upper part of each tube containing the plug
projecting into the water or other liquid, and the lower end projecting into or
towards the furnace. In order to admit of the fusible plugs being renewed
without having to enter the boiler I sometimes carry the upper part of the

page_text: tube, or a tube or rod attached thereto, through the steam space to the outside
of the boiler, and into a box attached to the shell of the boiler, and fitted with
a cap capable of being readily removed to obtain access to the interior of the
tube. The tube is tapered at the lower part or made smaller in bore at the
part required to be occupied by the plug, so that the plug of fusible metal
may be dropped into the tube and driven into position, or the tube may be
readily withdrawn for the purpose.
For the greater security of water heaters and "circulation" boilers, I in
some cases attach thereto a pipe of comparatively large diameter, which may
be fitted with branches for the service of the hot water if required. In a
circulation boiler this will contain the upward current, the down current
passing through smaller pipes or tubes contained inside the larger pipe,
whereby the current of water entering the boiler is divided into several
streams, and heated to some extent while passing through the smaller tubes.
In order that my Invention may be more readily described, and that the
description may be readily understood, I have attached hereunto a Sheet of
Drawings made for the most part about full size, and having letters of
reference marked upon the various Figures, referring here to the said
Drawings.
Fig. 1 is a section through a hollow metal weight drawn about one-quarter
the full size, and shews a method of forming the weights which are to be
employed to load the "Cowburns" safety valves. a, a, is the shell of the
weight, shewn here as of cast iron, and 6 is the filling material which may be
any suitable and ponderous material, or may be any of the substances
mentioned in a former part of this. Specification.
Fig. 2 is a vertical full sized section through a fusible safety valve con-
structed according to this Invention, Fig. 3 being a cross section of the same.
c is a fixing which may be cast or formed in one piece, or may be fitted with
a loose cap; d, d, are the tubes of copper, brass, or other suitable metal
having plugs of fusible. metal e, e, fixed in their upper ends. The fixing is
bolted or otherwise attached to the crown of the furnace f, the tubes d, d,
projecting a short distance into the interior of the furnace, and conducting the
beat from the said furnace to the "plugs" of fusible metal, by which means
the said plugs will be melted soon after being left uncovered by the water
contained in the boiler, the advantage attending the use of these plugs being
well understood.
Fig. 4 is a vertical section, and Fig. 5 a cross section through a fusible
valve adapted for one plug of fusible metal, the body of the valve being cast
in one piece and adapted to be screwed into the crown of the service.

page_text: Fig. 6 is a plan of under side of a fusible valve, the body of which is also
cast in one piece, but is adapted to receive four fusible plugs; the central
tube d is formed of a triangular shape, so as to form four passages for steam
or water, a plug of fusible metal e being fixed in the top of each passage.
Fig. 7. is a vertical section of a fusible valve drawn about half size, and so
arranged as that the plugs of fusible metal can be renewed without entering
the boiler. The tube g containing the "plug" extends through the steam
space and the shell of the boiler, so that by removing the cap ha fresh plug
can be dropped into the tube and driven into its place, or the tube may be
withdrawn for the purpose. Fig. 8 is a vertical full sized section of a similar
arrangement adapted for the use of two or more plugs of fusible metal. On
removing the cap h the rod i attached to the tube or tubes d containing the
'plugs" can be withdrawn from the interior of the boiler when it is desired
to renew the "plugs."
'
Fig. 9 represents a vertical section through a water heater or a portion of a
water heater, such as is ordinarily used for domestic purposes, the Drawing
being about half size, and shewing my improved safety apparatus. A portion
of an ordinary water heater is shewn at k, k, to this is attached a supple-
mentary vessel, l, which is connected to the water heater by the pipes m, m;
a safety valve n is fitted to this vessel, having a central pipe o, the lower end
of which is immersed in the water, and is closed with a plug of fusible metal e,
so that in the case of the "boiler" being overheated the plug will melt and
give vent to the steam or water. The descending current of water enters the
"heater" through the pipe p, p, and in the case of the velocity of the said
current being such as would be injurious to the heater the plate r on the
end of the levers receives the impact, and the opposite end of the lever raises
the safety valve, and relieves the heater of the extra pressure, pieces of ice
descending the pipes p, p, are retained by the grating t until melted.
Having now described the nature of my Invention, and shewn the method
of carrying the same into effect, I wish it to be understood that I claim more
particularly as my own Invention,―
First, forming the weights for loading "Cowburns" safety valves with one
or more hollow cells, to be afterwards filled as herein-before described.
Secondly, forming fusible valves with a tube or tubes which is or are
exposed to the heat of the furnace, and which conduct the said heat to the
plug of fusible metal, the said tubes being kept from contact with the water
by an outer casing either formed in a separate piece or in one piece with the
tube or tubes.
Thirdly, so constructing fusible valves as that they may be removed from

page_text: their place in the boiler without entering the boiler or discharging the water
from the same in the manner herein described, or in any mere modification
thereof.
And, lastly, the arrangement of safety apparatus for water heaters or any
portion thereof, as herein described, or any mere modification thereof.
In witness whereof, I, the said Thomas Cowburn, have hereunto set my
hand and seal, this Fourteenth day of September, in the year of our
Lord One thousand eight hundred and sixty-seven.
Signed and sealed by the said
Thomas Cowburn, in the
presence of
EDWARD K. DUTTON,
Patent Agent,
THOMAS COWBURN. (L.B.)
Manchester.