A SAFETY APPARATUS FOR STEAM BOILERS
Year: 1855

page_text: LETTERS PATENT to William Smith, of No. 10, Salisbury Street, Adelphi,
in the County of Middlesex, Civil Engineer, for the Invention of "A SAFETY
APPARATUS FOR STEAM BOILERS."-A communication from M. Adolphe
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PROVISIONAL SPECIFICATION left by the said William Smith at the Office
of the Commissioners of Patents, with his Petition, on the 23rd May
1855.
I, WILLIAM SMITH, of No. 10, Salisbury St., Adelphi, in the County of
Middlesex, do hereby declare the nature of the said Invention for "A SAFETY
APPARATUS FOR STEAM BOILERS," a communication from M. Adolphe Lethwilleon
Pinel, of Rouen, in the Empire of France, to be as follows:-
This indicator is intended to avoid all the inconveniences which appertain
to the ordinary floating apparatus for shewing water levels in steam boilers,
superseding the necessity for packing the stuffing boxes and keeping them
greesed; to reduce the friction of the rod which communicates between the
inside and the outside of the boiler, and also enables an alarm, a pressure
guage, and safety valve to be combined with the water indicator.
I effect these improvements by introducing a copper spheroid float which
has been thoroughly tested under pressure externally and internally applied;
to this float I attach a rigid metal rod, which passes through the boiler into a

page_text: steam-tight case, which is secured by its flange to the boiler. To the top of
this rod I attach a powerfull magnet; this magnet travels up and down within
a brass case, which may be a square in section on the plan, and in height
sufficient to shew the maximum and minimum levels, according with the
diameter of the boiler.
On one face of the case or box is a properly graduated scale in inches;
this scale is protected by a sheet of glass fixed a small distance from the face
of the scale. Between the scale and the glass an iron needle or finger is placed
therein, entirely free of any mechanical suspension, but is held to the face
of the graduated plate by the attraction of the magnet-contained within the
case and behind the graduated plate; thus a true and constant motion of the
finger will be produced by its following the motion of the magnet, which is
connected with or acted upon by the rising or falling of the float.
Within the brass case and at the top and bottom thereof-are-arranged-studs
or stops, against which the magnet will come in contact when the water in
the boiler is either too high or too low. These studs are so arranged that they
act upon a valve which is opened thereby, and the steam is thus permitted to
pass into the throat of the whistle to sound an alarm, that the attention of the
engine driver and others may be arrested.
In connection with my magnetic water indicator, the steam pipe and steam
whistle, a pressure guage, safety valve, or any other fitting may be worked, so
that but one opening in the boiler in addition to the man-hole need be made.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Smith in the Great Seal Patent Office on the
23rd November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
SMITH, of 10, Salisbury Street, Adelphi, in the County of Middlesex. Civil
Engineer, send greeting.
WHEREAS Iler most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto him, the
said William Smith, Her special licence that he, the said William Smith,
his executors, administrators, and assigns, or such others as he, the said
William Smith, his executors, administrators, and assigns, should at any

page_text: 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 "A SAFETY APPARATUS
FOR STEAM BOILERS," (a communication from M. Adolphe Lethuiller Pinel, of
Rouen, in the Empire of France, upon the condition (amongst others) that he,
the said William Smith, by an instrument in writing under his 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 William Smith, 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:
My Invention consists of an apparatus for indicating correctly on the
outside of a steam boiler the level or quantity of the water contained within
such boiler, and is acted upon by means of a hollow metal float connected to
the apparatus by a rod, but without the intervention of any gland, packing, or
stuffing box, through which leakage may take place; or which being liable
to set fast, as in the ordinary float or other indicating apparatus, and
whereby it is rendered inefficient, tending to produce explosions, and always
mischievous.
And my apparatus also affords further security from accident, and does not
require that close attention to its state which is necessary for other water
guages, floats, or indicators, inasmuch as by a very simple and self-acting
arrangement I cause a whistle of suitable construction, and, as hereafter-
described, to be sounded by the level of the water, either falling too low or
upon being increased beyond the proper height for working the boiler or engine
advantageously, by which the attention of the engine driver and other persons
is duly called thereto.
My apparatus further admits of all other openings into and projections
from the boiler, for the attachment of instruments being dispensed with; as
in addition to the water level indicator and self-acting danger alarum whistle,
the ordinary or other safety valve or valves, as also any kind of pressure
guage or similar apparatus may be connected therewith, and take their steam
from and through the same opening.
In the Drawing hereunto annexed I have shewn 3 Figures illustrating.
my Invention

page_text: Fig. 1 is an external view of the instrument, exhibiting the scale with the
indicating needle, the whistle, a safety valve, and the spheroidal float.
Fig. 2 is a vertical sectional view of Fig. 1, the side of the case upon
the safety valve elbow is cast being removed.
which
Fig. 3 is an enlarged sectional view of the upper part of Fig. 2, shewing
more clearly the several parts and their respective actions, as will herein-after
be described by the aid of letters of reference.
Figs. 1 and 2 have been drawn upon the base lines, which are intended to
represent the relative positions of the top of the boiler and the proper water
lovel, as indicated rather than as exhibiting a longitudinal and transverse
section of the same boiler, so that the flanch in each view is shewn flat,
whilst for fitting to the exterior of a cylindrical boiler the flanch would have
to be suitably curved.
I construct the apparatus according to my Invention as follows:-I employ
a hollow copper float a, spheroidal in form, having a metal rod b screwed
or otherwise secured, as shewn in Figs. 1 and 2, and previously to applying
it I test it to a pressure of 15 atmospheres, or 225 lbs. per square inch.
The extension of the rod 6 to a suitable length is effected by a jointed
rod c, which is in turn attached to the permanent magnet d and its brass
sheath frame or divisional supporter e, e, the magnet being formed as shewn
in Figs. 2 and 3, that its poles may be presented in close contact with and
to the back of the scale f of the brass case g, g; so that the steel needle h
on the outside of the case is attracted to and held against the face of the
scale f, which scale is graduated with inches, or with any other suitable
measurement; and in Fig. 1 this scale is shewn with the odd numbers on
one side, or in one column, and the even numbers on the other side of the face.
I place a sheet of strong plate glass i in slight rebates or grooves before the
face of the scale, and between which the needle slides or moves freely up and
down without being liable to external interference or injury. I prefer to
platinize or gild the face of the dial or scale to prevent it being discolored or
injured by heat, or from other causes.
The difference of the water level in the boiler is marked by its causing the
metallic spheroidal float a to rise or fall, and as it carries with it by means of
the rods b and c the magnet, as described, it indicates by the needle on the
scale the exact state of the water within.
On the top of the brass case g, g, I affix a steam-tight metal cover, having
a whistle k, of the kinds known as a "throat, a whip, or a dog whistle." The
steam is prevented from acting upon the whistle by a cone or button valve 7,
ground into a valve seat m at the bottom of the metal cover j; this valve

page_text: is mounted on a spindle n, which passes through the top of the cover j,
and has a milled nut screwed thereon; and under this nut is a slight spiral
spring e, which is partially recessed into the cover, and is intended to keep the
valve in its place when the pressure of the steam is removed from behind
the valve l, and to overcome the weight of the levers below.
The lower end of the valve spindle n has a cross pin, which works in the
crutch or eye of the horizontal lever p, which is mounted freely upon the
centre or fulcrum q. The lever p has its shorter end bent down, so as to
come in contact with the top of the brass sheath frame or divisional sup-
porter c, e. When the float shall have raised the magnet to a point sufficiently
high, and the effect of which is to depress the longer end of the lever p,
and so pulling down the valve spindle n, opens the valve l, and permits the
steam to pass into the whistle, and so giving an alarm. Now, to the longer
end of the horizontal lever pa rod r is attached by a joint, or instead of a
single rod a fork may be used, in either case terminating at the lower end
with a stud or cross pin 8, with which the brass sheath frame will come into
contact and press upon when the level of the water in the boiler falls below
the point to which this apparatus has been adjusted for safety, and upon
doing so will open the valve, in the manner before described, admitting the
steam into the whistle. Guide pieces are affixed to the magnet frame to
ensure its being properly guided within the brass steam-proof box or case con-
taining the several parts just referred to.
I apply the brass box or case 9, 9, either direct upon the boiler and bolt it
thereto by a flanch, when to be used alone; but when combined with a safety
valve, I fix it upon a stand pipe, as at t, in Figs. 1 and 2, from which may
project the elbow pipe v with the safety valve, and any other pressure guage
or apparatus that may be desired.
Having described my Invention, I have to remark, I am aware that magnets
have been used for giving indications of various kinds, and that they have
also been proposed to be used in certain ways for water guages; but what I
claim is,
1st, the application of a permanent magnet contained within a steam-tight
case for acting upon or suspending a needle or pointer outside of such case,
when such apparatus is used for indicating the level of the water contained
within the vessel to which it is applied-and-constructed in the manner-
described.
2nd, the duplex arrangement by which the maximum and minimum levels.
of the water call into action the whistle alarum.

page_text: 3rd, the application of the form or forms of whistle described to such or
similar magnetic indicators.
4th, the combination of a magnetic indicator with a whistle which is called
into action by the means described.
5th, the combination of a magnetic indicator with a safety valve or
pressure guage, or with a safety valve and a pressure guage, and with or
without a whistle.
In witness whereof, I, the said William Smith, have hereunto set my
hand and seal, this Twenty-third day of November, in the year of
our Lord One thousand eight hundred and fifty-five..
Witness,
JOHN WILLIAM TIBBERT,
10, Salisbury Street, Adelphi.
WILLIAM SMITH. (Ls.)