Year: 1887

page_text: Date of Application, 21st Mar., 1887.
Specification Accepted, 26th Apr., 1887.
I, FRANCIS ROBERT STEVENSON of Erie, in the County of Erie, and State of
Pensylvania, United States of America, Machinist and 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 :-
This invention relates to devices for sounding an alarm when the water in a steam-
boiler becomes too low or too high; and it consists in improvements in the construction
thereof, as will be hereinafter fully set forth, and pointed out in the claims.
My device is illustrated in the accompanying drawings, as follows: Fig. 1 shows
the apparatus in vertical section. Fig. 2 is a top view, looking into the shell, the top
or cover being removed. Fig. 3 is a vertical section through the puppet-valvo F.
The device consists of a cast-iron body or shell, A, which is connected with the
boiler by pipes G and H, and is provided with a steam-tight cover, A2, and contains
a floating ball and means for sounding an aların when the float is raised too high or
sunk too low.
The construction is as follows: The shell or body A is cylindrical in form, with the
bottom closed, and on one side there is a narrow extension or channel, a, along the
length of the body, and on the same side, at the top, there is a shallow rectangular
extension, A'. This shell is cast in one piece, and is covered by a cover, A², which is
secured to it by bolts and made steam-tight. A pipe, H, connects with the interior
of the shell at the bottom, and when the device is in place on a boiler this pipe connects
with the interior of the boiler below the lowest point to which the water should ever
be permitted to fall. A second pipe, G, connects with the interior of the shell at the
top and enters the steam-space of the boiler.

page_text: B is a float of the ordinary kind, which is contained within the cylindrical part of
the shell.
C is a cross-beam supported within the shell, across the cylindrical part thereof, at
the top, and containing sheaves c c.
B¹ is a chain or metallic cord, which is connected with the float and passes over the
sheaves c c in the beam C, and has suspended at its end a small weight, b. The
arrangement of parts is such that the weight bhangs within the channel or extension a,
above mentioned, and can pass the float undisturbed as the float rises or falls. The
weight is not a counter-weight, but is made only sufficiently heavy to keep the
chain B' taut and insure its movement over the sheaves c c as the float rises.
The chain B is connected with the float B by a screw-bolt, 63, on the end of which
is a disk, b. By turning the screw-bolt, the distance of the disk & from the float can
be regulated.
E is a steam-escape chamber. It is something the shape of a flat bottle. It will
preferably be made of brass, and will be cast in one piece. Its neck is screw-threaded
and screws into an opening through the end wall of the extension A¹ of the shell, and
an alarm-whistle, E', is connected with the same opening from the outside.
A puppet-valve, F, regulates the admission of steam to the chamber E, as is clearly
shown in Fig. 1. This valve is kept seated by a spring, f, and the tension of this is
regulated by a screw, f'.
In Fig. 3 I have shown the internal construction of the puppet-valvo F. It has a
central porforation, f, and a cap, f, with a chamber, f, below it, and in connection
with the opening f*.
The object of this construction is to properly balance the valve.
D is a lever fulcrumed at d on the under side of the chamber E, and passes under
the stem of the valve F, extends under the beam C, and embraces by slots therein at
dd the chain B¹ below each of the sheaves c c.
It will be seen by observing Fig. 1 that if the water in the shell A becomes too
low the float will sink and the weight will be drawn up and come in contact with the
lever D and lift it, and also that if the water becomes too high, the float will be raised,
so the disc will come into contact with the lever D and lift it, and also that any
such lifting of the lever D will lift the valve F from its seat and permit an escape
of steam into the escape-chamber E, and this escaping steam will sound the alarm-
whistle E'.
It will be noted that all the operative mechanism of the device is contained within
the shell and does not have to operate through any packed opening in the walls of the
shell, and hence there is no danger of inoperation. The only stuffing-box used is on
the stem of the screw, which regulates the tension of the spring on the valve F,
and this stem is always operated by hand from outside of the case, and hence in no
way effects the action of the operating parts.
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 :-
1. In a water-alarm for boilers, the combination, substantially as set forth, of
a float, a flexible chain or cord connected with said float; which passes over sheaves
and attaches to a weight, so that said weight will move counter to said float in
a parallel vertical plane, a steam-escape chamber, a valve regulating admission
to said chamber, and a lever for moving said valve, which is arranged with relation
to said float, chain, and weight in a manner substantially as shown, whereby the said
lever may be moved by the action of said parts to open said valve when the said float
is unduly elevated or depressed.
2. In a water-alarm for steam-boilers, the combination, substantially as shown
of a shell or case, A, connected with the boiler by a pipe extending from the top

page_text: of said case to the steam-space of the boiler, and a pipe extending from the lower
part of said case to a point below the low-water line of the boiler, a steam-escape
chamber within said case, and having its inlet controlled by a valve and its outlet
extending through the wall of said case, a lever for moving said valve, and a float
for operating said lever when the said float is unduly elevated or depressed.
3. In a water-alarm for steam-boilers, the combination, substantially as set forth,
of the shell or case A, connected with the boiler, as commonly, the steam-escape
chamber E, having its exit through the wall of the main case and its entrance
controlled by the puppet-valve F, the lever 1, for moving said valve, the float B, the
cross-beam C, having sheaves thereon, the weight, and the chain B', connecting
said weight and float and passing through slots din said lever D) and over said
sheaves c c in said beam C.