Year: 1887

page_text: I, MATTHEW BAILEY; of 69 Montpelier Road, Peckham, in the county of Surrey,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to the construction of a safety pressure and vacuum indicator
for use with steam and other boilers, pumps, hydraulic machinery, water mains, gas
mains, weighing machines, and other machinery cocks, taps, valves or other apparatus
working under pressure or vacuum, the main object of the invention being to provide
a novel and simple apparatus whereby any excess of pressure or vacuum above a given
point is indicated in any suitable place as may be required. My improved indicator
may also be arranged to operate as a detector, that is to say, it can be made to shew
that a fixed pressure has been exceeded should the alarm not have been noticed or in
the absence of the person in charge, and the indicator is also adapted to serve as a
water-level indicator.
For the sake of simplicity I will describe a suitable way of carrying out my
invention as applied to a steam boiler.
I employ a cylinder or casing adapted to be connected to the boiler in any suitable
manner so that its lower end may be open to the boiler.
In the said cylinder or casing works a tubular or annular piston or a suitable valve;
above the piston or valve is a guide chamber in which is arranged a spring which is
advantageously contained within a pressure piston and which spring can by means of
a screw or other suitable arrangement be adjusted to the required pressure.
By this arrangement if the pressure in the boiler exceeds the pressure to which the
apparatus has been set the annular piston or the valve in rising under the pressure
will compress the spring and thereby give an alarm in the required place by coming
in contact with a suitable electric arrangement or open a communication in the
cylinder or casing so as to allow the steam or water to pass through a pipe to the
required place and sound an alarm.
In the case of employing an electric arrangement for communicating the alarm the
pressure piston is made of a suitable material which is a non-conductor of electricity

page_text: a suitable conductor such as copper passing through the centre of the piston so that
until the top of the annular piston or valve comes against the lower end of the
conducting wire no current can pass.
In some cases where I wish my improved indicator to be used also as a detector I
provide the casing or cylinder with an opening adapted to be closed by a band or tube
which is also provided with a corresponding hole; this opening in the cylinder or
casing is covered or closed with any suitable material which will break or burst under
slight pressure.
When the detector is not required the said band is moved so as to cover the said
opening but when the detector is set the opening in the band. is made to correspond
with the opening in the cylinder, so that should there be an excess of pressure the
material covering the said opening will be burst.
When the apparatus is to be used as a water-level indicator I adapt thereto a
suitable cock or valve, by turning on which it will be at once seen whether
the water is at the proper level by water or steam passing out of the cock or
valve.
It will be obvious that instead of a spring adjustment for my indicator a weight or
weighted lever arrangement may be employed.
I have described my indicator as applicable to a steam boiler; its application to
other purposes or machinery- will be understood without further description.
It will be obvious that the apparatus can be enclosed in a locked casing to prevent
the same being tampered with.
I sometimes provide my instrument with an index in which case it can be used as
an ordinary indicator.
Dated the 2nd day of June 1887

page_text: "A Safety Indicator or Alarm for Apparatus Working under
.Pressure.
I, MATTHEW BAILEY, of 69, Montpelier Road, Peckham, in the County of Surrey,
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 the construction of a safety pressure and vacuum indicator
or alarm for use with steam and other boilers, engines pumps, hydraulic machinery,
water mains, ships' sounding apparatus gas mains, weighing machines, and other
machinery, cocks, taps, valves, or other apparatus working under pressure or vacuum,
the main object of the invention being to provide a novel and simple apparatus
whereby any excess of pressure or vacuum above a given point is indicated in any
suitable place as may be required. My improved indicator or alarm may also be
arranged to operate as a detector, that is to say, it can be made to show that a fixed
pressure has been exceeded should the alarm not have been noticed or in the absence
of the person in charge, and the indicator is also adapted to serve as a water-level
indicator.
For the sake of simplicity 1 will describe a suitable way of carrying out my
invention as applied to a steam boiler.
I employ a cylinder or casing adapted to be connected to the boiler in any suitable
manner so that its lower end may be open to the boiler. In the said cylinder-or
casing works a tubular or annular piston or a suitable valve; above the piston or valve
is a guide chamber in which is arranged a spring which is advantageously contained
within or borne upon by a pressure piston and which spring can by means of a screw
or other suitable arrangement be adjusted to the required pressure.
By this arrangement if the pressure in the boiler exceeds the pressure to which the
apparatus has been set the annular piston or the valve in rising under the pressure
will compress the spring and thereby give an alarm in the required place by coming
in contact with a suitable electric arrangement or open a communication in the
cylinder or casing so as to allow the steam or water to pass through a pipe to the
required place and sound an alarm.
In the case of employing an electric arrangement for communicating the alarm the
pressure piston is made of a suitable material which is a non-conductor of electricity,
a suitable conductor such as copper passing through the centre of the piston so that
until the top of the annular piston or valve comes against the lower end of the
conducting wire no current can pass.
In some cases where I wish my improved indicator to be used also as a detector I
provide the casing or cylinder with an opening adapted to be closed by a band or
tubular clip which is also provided with a corresponding hole; this opening in the
cylinder or casing is covered or closed with any suitable frangible material which will
break or burst under slight pressure.
When the detector is not required the said band is moved so as to cover the said

page_text: opening but when the detector is set the opening in the band is made to correspond
with the opening in the cylinder, so that should there be an excess of pressure the
material covering the said opening will burst.
When the apparatus is to be used as a water-level indicator I, in some cases, adapt
thereto a suitable cock or valve by turning on which it will be at once seen whether
there is sufficient water in the boiler, by water or steam passing out of the cock or
valve.
It will be obvious that instead of a spring adjustment for, my indicator a weight or
weighted lever arrangement may be employed; or the said lever can be used in
conjunction with a spring.
It will also be obvious that the apparatus can be enclosed in a locked casing to
prevent the same being tampered with.
I sometimes provide my instrument with an index and scale in which case it can be
used as an ordinary indicator.
In order to enable my invention to be fully understood I will proceed to
describe how it can be carried into practice by reference to the accompanying
drawings, in which
Figure 1 is a vertical section of my improved safety indicator or alarm as applied
to a steam boiler for indicating the level of the water and excess of steam pressure
therein; and adapted to act also as a detector.
Figure 2 is an elevation partly in section of my apparatus for ascertaining if there
is sufficient water and indicating the steam pressure in a boiler and having a cock
or valve adapted thereto.
.
Figures 3 and.4 are respectively an elevation and a vertical section showing my
improved indicator provided with a weighted lever and spring arrangement and an
index and scale.
Referring to figure 1, the cylinder or casing when the apparatus is required to act
as a water level indicator in the manner hereinafter described is formed in two
parts a and a', the lower part is fixed in the shell b of the boiler and is open to
the interior of the latter, c is the valve working in the upper part a' of the cylinder
or casing..
d is the guide chamber above the valve c, and e is the spring arranged within the
chamber d; fis the pressure piston situated in the chamber d and bearing upon the
top of the spring e, the lower end of the spring bearing upon the top of the valve c;
g is the screw for adjusting the spring to the required pressure by bearing upon the
piston f. The said screw works through the top of the chamber d.
a is a handle or lever passing from the valve c to the exterior of the apparatus and
serving to test the efficiency of the said valve.
The operation is as follows :-
The screw g is operated so as to produce through the piston f a greater or less
compression of the spring e and consequently a pressure upon the valve corresponding
to that which it is desired shall not be exceeded by the steam in the boiler b. Should
this pressure be exceeded the steam will force open the valve c and pass out of the
apparatus through any suitable opening or tube to the place where the alarm is to be
given.
h is the copper conductor which I provide when an electric arrangement is employed
for communicating the aların; the said conductor consists of a rod passing through
the centre of the piston f which is then made of material that is a non-conductor of
electricity. The rod / extends downwards to within a short distance of the top of
the valve c.
A capi and a flanged tube; are screwed to the upper part a¹ of the cylinder or
casing.
The tube is bolted to a cap & screwed over the tube forming the guide chamber d
but is electrically insulated from the said cap by the interposition of a piece or pieces
of insulating material l.
Wires m and n respectively are led from the caps i and k to the electrical apparatus
provided for giving the required indication or alarm.

page_text: It will thus be seen that the upper part of the apparatus is normally insulated from
the lower part and that the valve c forms a contact-maker and breaker, so that when the
latter is raised by an excess of steam pressure in the boiler the electric circuit
will be completed by the valve c being forced up into contact with the conducting
rod h.
The current then passes through the cap i, part a¹ of the cylinder or casing, valve
rod: h, screw 9, tube d, and cap k, and the indication or alarm will be given.
.:
C₁₂
o is the band or tubular clip which in some cases I provide where I wish niy
improved indicator. to be used also as a detector, the said band or clip having a hole p.
therein corresponding with the hole q in the tube j forming a continuation of the
casing or cylinder a, a¹; the band or clip o can be rotated on the tube j.; r is the
frangible material which I employ to cover the opening 9 and which is interposed
between the tube j and the band or clip o as shown.
From this arrangement it will be readily understood that if the holes p and q be
brought one over the other as shown in figure 1; an excess of pressure in the boiler.
would cause the material to burst or become broken and the steam would rush out
through the said holes and give the necessary indication or alarm.
When however
the detector is not required to act, the band or tubular clip o can be rotated upon, the
tube so as to cover the hole q in the latter.
When my improved apparatus is required for use as a water level indicator I can
advantageously employ the arrangement shown at the lower part of figure 1, wherein a
is a lever carrying a weight t at one end and a float u at the other end. The lever s
has a rod v attached thereto extending upwards to within a short distance of the
under side of the valve c and so long as the water is at the required level bears
upon two knife edges w and x formed in an extension y of the part a of the casing or
cylinder.
The two knife edges w and serve as fulcra for the lever s.
The casing or cylinder is formed in two disconnected parts a and a¹, and a flanged
tube z is screwed over the lower part a and is bolted to the cap i but electrically:
insulated therefrom by interposed insulating material b¹.
Wires m and c leading from a suitable electrical indicator or alarm are .connected
to the cap i and tube z respectively.
..
By this construction when the water falls below the required level the floatiusin
descending will raise the weight end of the levers the knife edge a then, becoming
the fulcrum of the lever. The rod v will be thereby raised and will come in contact
with the valve c, an electrical connection will be established between the wires m and c¹
through the cap i part a¹ of the casing or cylinder, valve c, rod v, lever s, extension y,
part a of the casing or cylinder and flanged tube and the required indication or
alarm will be thereby given.
E
Water is then introduced into the boiler and when it has risen beyond the required
level the float in rising will raise that end of the lever to which it is attached, the
knife edge w then becoming the fulcrum, the rod will be raised into contact with
the valve c and the indication or.alarm will be given in a similar manner to that last
hereinbefore described.
.
Figure 2 illustrates the arrangement which I sometimes employ when the apparatus
is to be used for the purpose of ascertaining if there is sufficient water in a boiler.
d' is the cock or valve adapted to the apparatus in the manner shewn so that it is
in communication with the casing or cylinder j and with an extension e¹ thereof the
lower end of which when the water is above a certain level is immersed therein but
which becomes uncovered by the water when the latter has fallen below the said level
so that by turning on the cock or valve d¹ it can be ascertained whether there is
sufficient water in the boiler, by water or steam passing out of the cock or
valve d¹.
The apparatus otherwise, as regards the arrangement of casing or cylinder, valve,
guide chamber, spring, pressure piston, screw and parts connected therewith is similar
to that hereinbefore described and illustrated by the upper portion of figure 1.
In figures 3 and 4, which shew how a weighted lever arrangement can be used

page_text: instead of or in conjunction with a spring adjustment, fi is the lever pivotted at gl
and provided with an adjustable weight h. The lever f¹ passes through a slot in an
upward projection on the valve c.
By varying the position of the weight h' along the lever f¹ it will be evident that
the pressure on the valve c can be varied.
The said figures 3 and 4 also illustrate the manner in which an index and scale can
be used on the apparatus when a spring adjustment is employed. The index or.
pointer is fixed to the pressure piston fand when the latter is moved to produce
more or less pressure upon the valve c the index will be moved to a corresponding
extent over the scale which will in this way indicate to what pressure the apparatus
is adjusted.
I have described my indicator as applicable to a steam boiler; its application to
other purposes or machinery will be understood without further description.
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 safety indicator or alarm the combination of a pressure piston made of
suitable insulating material, a spring or weighted lever and an electrical conducting
rod with a valve or piston so arranged as to automatically establish an electric
current and thereby operate an indicator or alarm, substantially as hereinbefore
described and illustrated in the accompanying drawings.
2. The combination with apparatus such as is claimed in claim 1, of a tube such
as e¹ and a cock or valve to allow of ascertaining when the water in a steam boiler is
below its nornal level, substantially as hereinbefore described and illustrated in
figure 2 of the accompanying drawings.
3. The use in combination with indicator or alarm apparatus of a detector con-
sisting of a perforated band or tubular clip and a suitable frangible material, as, and
for the purposes, hereinbefore described and illustrated in figure 1 of the accompanying
drawings.
ر
4. The manufacture and use of the improved safety indicator or alarm apparatus
herein before described and illustrated in figures 1, 3, and 4 of the accompanying-
drawings.