IMPROVEMENTS IN AUDIBLE SIGNALLING APPARATUS
Year: 1882

page_text: LETTERS PATENT to John Steven and Thomas Burt both of Glasgow in the
County of Lanark North Britain, Brassfounders for an Invention of
"IMPROVEMENTS IN AUDIBLE SIGNALLING APPARATUS
PROVISIONAL SPECIFICATION left by the said John Steven and Thomas
Burt at the Office of the Commissioners of Patents on the 16th December
1882.
JOHN STEVEN and THOMAS BURT, both of Glasgow in the County of
Lanark, North Britain, Brassfounders, "IMPROVEMENTS IN AUDIBLE SIGNALLING
APPARATUS,"
This Invention relates to improvements in audible signalling apparatus of the
kind known as sirens or gyrophones which are used mainly as fog or other signals
in steam-ships, locomotive engines, public works, and for general alarum purposes.
In such apparatus loud notes or sounds are produced by the action of steam or
compressed air escaping through orifices in two discs or cylinders, one of which is
rapidly rotated while the other remains stationary.
The present Invention comprises improvements in the construction of such
apparatus, and in the means of operating the same, the distinguishing feature
being (1) that instead of employing discs or cylinders carried by central spindles,
annular rings or cylinders, formed with slots or orifices, are caused to rotate upon
similarly slotted stationary rings or cylinders, while the steam or compressed air
flows through the orifices, and (2) that the rotating rings or cylinders are directly
actuated by the steam or compressed air without the intervention of carrying
spindles and driving gear.
According to one modification of the Invention, a fixed casing which may be of
cylindrical or other convenient form, and which is connected to a steam boiler or to
a pipe or vessel containing or conveying steam or compressed air to it, is formed
with a hollow cylinder at its upper end, fitted with a close cover on the top. The
outer periphery of the cylinder is truly turned, and on it is fitted a loose annular
or hollow cylinder with its inner periphery turned or bored, so that it may revolve

page_text: freely on the fixed cylinder. Both cylinders are formed at intervals with deep
slots or apertures through them which may be radial, or be inclined to each other,
so that the steam or air issuing from the inner apertures or orifices may strike the
sides of the outer orifices in the outer cylinder and cause it to continue revolving
after rotatory motion has been imparted to it. The outer or movable cylinder or
annulus is formed with outwardly projecting vanes or buckets at intervals round
the periphery, and on the casing of the stationary cylinder are formed one, two or
more adjustable nozzles or jets directed against the vanes or buckets, or faces of the
slots. These nozzles are in communication with the steam or air space of the casing,
and steam or air issues through them, and strikes the vanes or buckets, thereby
causing the outer cylinder or annulus to rotate. A cock or valve is fitted in the
stationary casing by preference opening against the pressure of the steam or com-
pressed air, and this valve is opened or closed by a lever, the extent of opening
being regulated if desired by a screw or similar device.
When the valve is opened the steam or compressed air passes through the fixed
nozzle or nozzles, and by striking on the buckets or vanes on the movable annulus,
causes it to rotate rapidly carrying the orifices of the outer cylinder past those of
the inner cylinder. The steam or air at the same time passes through the centre of
the inner cylinder and escapes by the orifices, thereby producing a continuous note
or sound, the pitch or tone of which will depend mainly on the pressure of steam
or air maintained, and on the velocity of rotation of the outer disc. To provide
means for varying the velocity of rotation of the outer cylinder and changing the
sound produced, a regulating valve may be fitted in the port or passage through
which the steam or air passes to the nozzles or jets.
In a modified arrangement, an annular steam space is formed round the casing
of the apparatus, and is formed with narrow slots cut obliquely and directed
inwards against a number of angled or curved buckets or vanes formed round the
outer moving cylinder of the siren. These vanes or buckets are by preference
formed on the cylinder either above or below the slots or apertures cut in it so that
the jets of steam or air used for driving the outer cylinder may not interfere with
the action of the jets issuing from the orifices in the siren.
The steam or air for driving the cylinder is by preference led from a separate
inlet for the purpose of obtaining the full pressure, such inlet being opened and
closed by the valve which admits the steam or air to the inner cylinder of
the siren.
:
In a further modification the rotation of the outer cylinder of the siren is
effected by the issuing of the steam or compressed air through curved nozzles or
apertures in a disc or plate connected to the outer cylinder, and to a central hollow
shaft passing out through the cover of the inner cylinder. In this case a bracket
may be fitted to carry the bearings or centre on which the nozzle disc rotates.
The new arrangements herein described for effecting rotation of the outer
cylinder of the siren, may also be applied to effect the rotation of the moving per-
forated disc in, the old forms of disc sirens. The rotating disc may be fitted for
example with a series of vanes or buckets on its upper side, and against these vanes
a series of nozzles or jets of steam or air may be directed, such steam or air being
led from the casing below from which it escapes through the orifices in the discs.
Or the steam or air may be led through a hollow shaft into and through curved
nozzles or jets fixed on the rotating disc, and forming a species of steam or air
turbine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Steven and Thomas Burt in the Great Seal Patent Office
on the 15th June 1883.
JOHN STEVEN and THOMAS BURT, both of Glasgow, in the County of
Lanark, North Britain Brassfounders "IMPROVEMENTS IN AUDIBLE SIGNALLING
APPARATUS,"
Our said Invention relates to improvements in audible signalling apparatus of the
kind known as sirens or gyrophönes which are used mainly as fog or other signals
in steam ships, locomotive engines, public works, and for general alarum purposes.
In such apparatus loud notes or sounds are produced by the action of steam or
compressed air escaping through orifices in two discs or cylinders, one of which is
rapidly rotated while the other remains stationary.
The present Invention comprises improvements in the construction of such
apparatus, and in the means of operating the same, the distinguishing features
being (1) that instead of employing discs or cylinders carried by central spindles,
annular rings or cylinders formed with slots or orifices, are caused to rotate upon
similarly slotted stationary rings or cylinders, while the steam or compressed air
flows through the orifices, and (2) that the rotating rings or cylinders are directly
actuated by the steam or compressed air without the intervention of carrying
spindles and driving gear.
Our Invention is illustrated by the accompanying Drawings, in which figure 1 is
a sectional elevation, and figure 2 a sectional plan of one modification of the
improved siren. Figures 3 and 4, 5 and 6, 7 and 8, and 9 and 10 are similar views
of different modifications of the Invention.
According to the modification shown in figures 1 and 2, a fixed casing A which
may be of cylindrical or other convenient form, and which is connected by the
flange A or otherwise, to a steam boiler or to a pipe or vessel containing or
conveying steam or compressed air to it, is formed with a hollow cylinder B at its
upper end, fitted with a close cover B¹ on the top. The outer periphery of the
cylinder B is truly turned, and on it is fitted a loose annular or hollow cylinder C,
with its inner periphery turned or bored, so that it may revolve freely on the fixed
cylinder B. Both cylinders B, C, are formed at intervals with deep slots or
apertures b, c, through them which may be radial, as in figure 4, or which may be
inclined to each other as in figures 2, 6 and 8, so that the steam or air issuing from
the inner apertures or orifices b may strike the sides of the outer orifices c in the
outer cylinder C, and cause it to continue revolving after rotatory motion has been
imparted to it. The outer or movable cylinder or annulus C is formed with out-
wardly projecting vanes or buckets C' at intervals round the periphery, and on the
casing A. of the stationary cylinder are formed one, two, or more adjustable nozzles
or jets D directed against the vanes or buckets C¹, or against the faces of the slots c.
These nozzles D are in communication with the steam or air space of the casing A
by means of ducts d, and steam or air issues through them, and strikes the vanes
or buckets C', thereby causing the outer cylinder or annulus C to rotate.
A cock or valve E is fitted in the stationary casing by preference opening
against the pressure of the steam or compressed air, and this valve is opened or
closed by a lever F jointed to a bracket F¹ on the casing A, the extent of opening
being regulated if desired by a screw. G or similar device, as is indicated in
figure 3.
When the valve E is opened, the steam or compressed air passes through the
casing A, the duct d, and the fixed nozzle or nozzles D, and by striking on the

page_text: buckets or vanes C₁ on the movable annulus C causes it to rotate rapidly, carrying
the orifices c of the outer cylinder C past those b of the inner cylinder B. The
steam or air at the same time passes through the centre of the inner cylinder B,
and escapes by the orifices b, c, thereby producing a continuous note or sound, the
pitch or tone of which will depend mainly on the pressure of steam or air main-
tained, and on the velocity of rotation of the outer annulus C. To provide means
for varying the velocity of rotation of the outer cylinder C, and changing the
sound produced, a regulating valve such as H in figure 3, may be fitted in the port
or passage d through which the steam or air passes to the nozzles or jets D.
In the arrangement shown in figures 3 and 4, an annular steam space D¹ is
formed round the casing A of the apparatus, and is formed with narrow slots d' cut
obliquely and directed inwards against a number of angled or curved buckets or
vanes C¹ formed round the outer moving cylinder C of the siren. The vanes C¹
are in this case in a lower plane than the orifices b, c, and being partially enclosed,
an approximately uniform speed of rotation may be given to the retaining annulus C,
and a uniform note produced.
The steam or air for driving the cylinder C is by preference led through a
separate inlet a for the purpose of obtaining the full pressure to act on the vanes C₁,
such inlet a being opened and closed by a projection on the valve E which admits
the steam or air to the inner cylinder B of the siren. Or otherwise, the steam may
pass freely through an opening a¹ and be admitted through duct and space
C2, D', by the hand screw valve H, or by the valve I, which is opened by a pro-
jection on the lever F, bearing on the stem i of the valve, and acting against the
power of a spring I' which tends to keep the valve closed. The siren shown in
figures 5 and 6 differs only from the modifications already described in having the
jets D which drive or start the outer cylinder C, formed in a disc D' cast on the
case A, and inclined upwardly and laterally, so that the jets issue at an angle and
strike against projecting edges or vanes C₁ formed on the rotating cylinder C.
In the modification shown in figures 7 and 8, the rotation of the outer cylinder C
of the siren, is effected by the issuing of the steam or compressed air through curved
nozzles or apertures J, in a disc or plate J' connected to the outer cylinder C, and
to a central hollow shaft K passing out through the top B' of the inner cylinder B.
In this case a bracket L secured to the casing A, and fitted with a screw centre
pin is provided to carry the bearings or centre on which the nozzle disc J¹ rotates.
The valve E for controlling the admission of steam to operate the siren is in this
example fitted in a seat E¹ formed by a mid-feather in the casing A, and the
valve E is operated horizontally by a lever F acting against the power of a
spring F on the valve spindle e which passes out through a stuffing box in the
casing A. This construction of valvé may be fitted in combination with the steam
casings of any of the forms of siren shown in the Drawings.
The new arrangements herein described for effecting rotation of the outer
cylinder (C) of the siren, may also be applied to effect the rotation of the moving
perforated disc M over the fixed disc M¹ in the old forms of disc sirens, as is
indicated in figures 9 and 10. The rotating disc M is fitted for example with a
series of vanes or buckets M² on its upper or outer side, and against these vanes M³,
a series of nozzles D or jets of steam or air may be directed, such steam or air
being led from the casing A below, from which it escapes through the orifices m, m¹
in the discs M, M. Or the steam or air may be led through a hollow shaft into
and through curved nozzles or jets fixed on the rotating disc and forming a species
of steam or air turbine similar to that shown in figure 8.
Having now described the nature of our Invention, and the manner in which the
same is to be performed, we declare that what we claim as our Invention is ;-
First. The construction or combination of parts of sirens or signalling apparatus,
substantially in the improved modes herein described, and illustrated by the
accompanying Drawings.
"
Second. The combination in sirens or similar signalling apparatus, of a stationary

page_text: perforated cylinder, and a rotating perforated cylinder or annulus adapted thereto,
and operated substantially as herein described and illustrated.
Third. The combination in a siren of the stationary cylinder B, the rotating
cylinder or annulus C provided with vanes or buckets C', and the nozzles D
adapted to direct steam or compressed air against such vanes or buckets, substantially
as herein described and illustrated.
Fourth. In a siren, the perforated cylinder or annulus fitted on a stationary
perforated cylinder, and provided with projecting vanes, buckets or faces against
which jets of steam or air are directed to rotate the cylinder, substantially as herein
described and illustrated.
Fifth. In a siren, the combination with the rotating perforated cylinder, of a
series of curved ducts adapted to direct outwards jets of steam or air and cause
rotation of such cylinder over a fixed cylinder, substantially as herein described and
illustrated.
Sixth. In a siren, the inclined nozzles or jets fixed on or formed in the siren
casing, and adapted to directs jets of steam or air against projecting vanes on the
moving cylinder or disc of the siren for starting and rotating the same, substantially
as herein described and illustrated.
In Witness Whereof, we the said John Steven, and the said Thomas Burt,
have hereunto set our hands and seals this thirteenth day of June, in the
year of our Lord One thousand eight hundred and eighty three.
Witness,
WR M THOMSON Fel. Inst. P. A.
Glasgow.
(L.S.)
JOHN STEVEN
THOMAS BURT. (L.S.)