Improvements in Automatic Fire-extinguishing Apparatus.
Year: 1889

page_text: Date of Application, 6th Aug, 1889-Accepted, 14th Dec., 1889
Improvements in Automatic Fire-extinguishing Apparatus.
I, JAMES READ GRAY, of Ayer, in the County of Middlesex and State of Massa-
chusetts, United States of America, gentleman, do hereby declare the nature of my
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 has for its object to provide a sprinkler head having a construction
by means of which the pressure of the water in the pipes to which the sprinkler is
attached shall be utilized to hold the valve to its seat when the sprinkler is not in
operation, and thereby prevent the danger of leakage, and at the same time the force
of the same pressure shall be utilized to force the valve open when the usual fusible
joint has been melted and it is desired that the sprinkler should come into operation.
My invention is further designed to provide an improved form of fusible joint
which shall be opened by the action of heat.
Referring to the accompanying drawings, Figure 1 is a central vertical section of
my improvement. Fig. 2 is an enlarged sectional view of the fusible joint. Fig. 3 is
an enlarged sectional view of a modified arrangement of the parts which constitute
the fusible joint.
In Fig. 1 the casing a is adapted to be connected with the distributing pipes in
the usual manner.
This casing is provided with the valve seat and also with the
chamber d. Such chamber being preferably located over and in line with the valve
seat and above the surface of the water in the casing a, although it may be located at
the side of or below the casing. The chamber d is provided with a vent or outlet
closed by means of a fusible joint, as hereinafter described.
The valve is seated upon the valve seat in the usual manner. It is provided
with the valve stem e and head b, the head being connected with the valve by means
of the stem and having an area greater than that of the valve f. It is also fitted.
loosely within the chamber d and is adapted to move freely up and down therein.
The operation of the valve is as follows:-The outlet or vent to the chamber d
being closed by means of the fusible joint and the head being fitted loosely, the
pressure passes freely around the head and into the chamber above it, so that the
pressure is the same on both sides of the head and it is therefore neutral in its effect
upon the valve, leaving the entire pressure to operate upon the valve to force it to
its seat.
Should the fusible joint be now softened by the action of heat, the pressure within
the chamber d will force the joint open and the pressure within the chamber and
above the head will be at once relieved, while the pressure on the under side of the
head will continue as before and, its area being greater than that of the valve, the
valve will be lifted from its seat by the excess of pressure and the water will escape
through the opening o of the valve seat.
It is obvious that the head b may fit very loosely in the chamber d, provided that it
exceeds in area the valve, and provided also that the capacity of the outlet to the
chamber is at least equal to the leakage around the head, so that there shall be no
accumulation of pressure above the head after the vent has been opened by the action
of heat.
The vent or outlet to the chamber d is closed and controlled by means of a fusible
joint formed in connection with the nipple . The upper end of the nipple is provided
with one or more grooves or indentations which may be either internal or external,
as preferred. The plug which closes the outlet is also provided with similar
grooves or indentations and is sealed to the nipple by means of fusible material
imposed between such parts and received into the said grooves or indentations, as
shown ut e. This material is preferably of a non-metallic substance as Parafine,
Wax, Resin, &c., such substances being more sensitive to the action of heat and less

page_text: liable to change their softening point after long disuse, than is the case with metallic
substances.
The plug is preferably made hollow, as shown, in order to present a greater
surface to the action of heat, and the grooves or indentations serve to further increase
such surface and also to insure the holding of the plug against the pressure.
In
practice I usually prefer to make the nipple and plug tapering, as shown, in order
that the plug may be released and forced ont more promptly when the fusible material
has become softened by the heat of a fire; the grooves or indentations being sufficient
to hold the plug against the pressure at usual temperatures. It is not essential that
such grooves or indentations be formed in both the nipple and plug, as it is sufficient
to form them in one only when the pressure is not excessive. I have found by
experiment that non-metallic substances having a degree of hardness sufficient to hold
against the internal pressure cannot be depended upon to form an air tight joint at e:
to provide against this and insure against leakage, I apply at el a non-metallic sub-
stance of a less degree of hardness and sufficiently soft to adhere at all times to the
interior of the nipple i, and adapted to be softened and pushed out in the same manner
as the harder section above. By thus closing the outlet from the chamber d by means
of sections of fusible material of different degrees of hardness a new and useful result
of great practical value is secured.
I do not limit myself to the use of the plug g in closing the outlet to the chamber d,
as it is obvious that the plug may be omitted and the outlet be filled with a plug made
entirely from fusible material.
Neither do I limit myself to the use of grooves or indentations to hold the plug
against the pressure, as the same results may be obtained by means of a reverse taper,
or by perforations, or other well known equivalent means.
as
In some cases also I have found it more convenient to reverse the parts / and
shown in Fig. 3, the plug being inverted and acting as a cap to close the outlet, but
combined and sealed to the nipple by means of the fusible material at e, in the same
manner as in Fig. 2.
It will be seen that by the arrangement of the parts i, g and e as shown, the
plug or cap y, which closes the vent or outlet to the chamber d is insulated from
contact with the nippleby means of the fusible material e, so that none of the
heat which may be taken up by the plug or cap in case of fire can be conducted
away by the walls of the nipple without first passing through the fusible material e,
which is softened by such passage, and the plug or cap released. This fact renders
the device very sensitive to the action of the heat of a fire.
The casing a when made as shown has a place on both sides to receive the
water pipes and the casing is placed directly in the run of the supply pipos and
takes the place of a Tee it being of course understood that with all other forms
of Sprinklers it is necessary to introduce a Tee fitting into the run of pipe to
receive the sprinklers: excepting however that when the ordinary sprinkler is to
be attached to the extreme or "dead end of a run. In this case an elbow is put
on to receive the sprinkler.
In practice the head may be made to fit the bore of the chamber d, and the
pressure admitted into the chamber by means of perforations througli the head. I
regard the loose fit as preferable however.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
1st. In an automatic fire extinguisher, a casing adapted to be connected to the
water pipes and provided with a valve seat having an opening for the escape of
water and with a chamber located in line with the valve seat, said chamber having
an outlet closed by means of a fusible joint, combined with a valve provided with
a head connected with and having an area greater than that of the valve and
fitted loosely within said chamber, substantially as set forth.
2nd. In an automatic fire extinguisher, a vent or outlet and a plug or cap to

page_text: close the same, the walls of both such parts being grooved or indented to receive
the fusible material which unites them and tapered to release such cap or plug
more promptly, substantially as set forth.
3rd. In an automatic fire extinguisher, a vent or outlet and a plug or cap to close
the same, the walls of both such parts being grooved or indented and sealed together
by means of fusible material imposed between them and received into the said grooves
or indentations, combined with a section of fusible material of a less degree of hardness
imposed between the harder fusible material and the internal pressure, to prevent the
escape of such pressure. substantially as sei. forth.
4th. The nipple or outlet having its walls grooved or indented, and the plug g
having its walls grooved or indented, the said plug being counter bored to expose its
interior to the action of heat and scaled to the said nipple by means of fusible
material imposed between them and received into the said grooves or indentations,
substantially as set forth.
5th. A casing adapted to be connected with the water pipes, a valve seat within the
casing having an opening for the escape of water, a chamber located in line with the
valve seat and communicating with the interior of the casing, a valve held to the valve
seat by the internal pressure, a head connected with and having an area greater than
that of the valve and fitted within the said chamber and which permits the pressure
to pass freely from the casing into the chamber above the head, and a vent or outlet
from the chamber, whose area exceeds the leakage into the chamber, substantially as
set forth.
Datad this 50th day of Luna d 11 1980
JAMES READ GRAY.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.