IMPROVEMENTS IN AUDIBLE SIGNALLING APPARATUS
Year: 1884

page_text: We, JOHN STEVEN and THOMAS BURT both of the firm of Stevens & Struthers
32 Elliot Street Glasgow, in the county of Lanark, Brass Founders, do hereby
declare the nature of our said invention for "IMPROVEMENTS IN AUDIBLE
SIGNALLING APPARATUS" to be as follows:-
This Invention consists of improvements in the construction of sirens or
gyrophones of the kind described in the Specification of Letters Patent granted to
us and dated 16 December 1882 N° 6018. The signalling apparatus therein
described and now referred to consists essentially of a stationary cylindrical casing
and a loose rotating cylinder or annulus fitted thereon and caused to produce
audible signals by the action of compressed air or steam passing through the
lateral ducts in it and in the stationary casing.
In lieu of leading the compressed air or steam through the perforated fixed
casing, we, according to our present invention, lead it through an annular space
formed between an outer unperforated casing and the cylindrical casing in which
the lateral ducts are formed, and we fit the loose rotating cylinder or annulus
within the fixed casing, an open outlet for the steam or compressed air through a
fixed or moveable mouth piece being provided. The rotation of the loose annulus
may be effected by the passage through the lateral ducts formed in it of the steam
or compressed air, or by the action on projecting vanes, formed on its internal
surface, of steam admitted through ports in a central tube or casing forming part
of the main fixed casing.
In order to direct the sounds produced in any direction, the curved trumpet
mouthpiece usually fitted to such signalling apparatus is arranged to swivel on
the fixed casing, and is secured thereto by a screwed coupling ring or similar device.
Dated this Dish daw CNL A 1004

page_text: We, JOHN STEVEN and THOMAS BURT, both of the firm of Stevens & Struthers
32 Elliot Street, Glasgow, in the county of Lanark, Brassfounders, do hereby
declare the nature of our invention for "IMPROVEMENTS IN AUDIBLE SIGNALLING
APPARATUS," and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement in writing, reference
being had to the accompanying Sheet of Drawings, and to the letters and figures
marked thereon, that is to say :-
This invention consists of improvements in the construction of sirens or
gyrophonos of the kind described in the Specification of Letters Patent granted to
us and dated 16 December 1882 N° 6018. The signalling apparatus therein
described and now referred to consists essentially of a stationary cylindrical casing
inside and a loose outer rotating cylinder or annulus fitted thereon and caused to
produce audible signals by the action of compressed air or steam passing through
the lateral ducts in it and in the stationary casing.
---
Referring to the accompanying Sheet. of Drawings, Figures 1 and 2 are
respectively a vertical elevation and a plan, both being shown in section each on
the lines 1. 1 and 2 2 on the other to show the general construction and
action of a modification of siren or gyrophone constructed in accordance with our
invention or improvements. A is the outer or main fixed case carrying the whole
portably, secured by its basement flange A' to the branch pipe of the steam or air
pressure fluid which is to work.it. Figure 3 is a horizontal section on the
line 3 - 3 in Figure 1. Figure 4 is a horizontal section of the inlet controlling
valve D, on the line 4
4 Figure 1, through the recess in which its actuating
lever works. Figure 5 is an elevation and plan, one half in section, on the
lines 5- 5, each on the other of the hollow central cap E, with the jet holes c
for starting or assisting the motion of the revolving inner slotted ring or annulus C,
which is also shown in sectional elevation and plan in Figure 6 on the lines 6 - - - 6,
each on the other, and respectively.shown detached from the general views Figuros 1
to 3, to indicate their construction more clearly.
---
Referring to these Figures, instead of leading the compressed air or steam through
the perforated fixed inner casing, as done in the said previous Specification, we
according to our present invention lead it as indicated by the arrows, from the
inlet valve D, to and through an annular space a formed between the outer
unperforated or main containing casing A and the fixed cylindrical casing B
screwed or otherwise secured in the casing A, and in which lateral ducts b are
formed, and we fit the loose rotating cylinder or annulus C, with its corresponding
ducts c through it, within the fixed casing B, a central opening F being provided
for the escape or outlet of the steam or compressed air through a fixed or movable
mouthpiece or trumpet G. The rotation of the loose annulus C is elfected mainly
by the passage of the steam or compressed air through the lateral ducts or slots b, c,
formed in the stationary casing B, and the revolving ring C, and started or assisted
by the action of a jet or jets of the pressure fluid projected through the orifices e,

page_text: in the fixed central cap E, acting on projecting vanes c¹ formed on the internal
surface of the revolving ring C.
The stationary hollow cylinder B, is shown as screwed into the outer case A
from the top, but it might be otherwise fitted and secured. It is truly bored or
turned on the inner surface, and has the loose revolving ring or hollow annular
cylinder truly turned to revolve freely in and be steadied and sustained by it.
Both the fixed and revolving cylinders B and C are formed with corresponding
slots, ducts, or apertures b and c at regular intervals apart and at an angle towards
or crossing each other, so that the steam or air in passing through the apertures b
in the fixed cylinder B, is directed against the sides of the aperture c in the
revolving disc C to actuate it, the angles of the slots being made to suit the force
of the steam or air current, and the speed of the ring C required to give the notes
or sounds desired, and as seen particularly in Figure 2.
Projections or vanes c (or it might be small "buckets") are formed at intervals
round the lower inner surface of the revolving ring C, at an angle towards one, two,
or more small jet holes e projected at an angle towards these through the side of
the hollow cap E, screwed in the close end of the main steam or air branch A³,
having the inlet valve D fitted in it. The jets from the holes e acting on the
vanes c start the motion of the ring C when the slots c are covered or not open to
those 6 in the stationary case B, or assist its motion when driven by the current
passing through these slots band c.
The steam escaping intermittently through the stationary and revolving
openings c and 6 as they open and close by the rotation of the ring B produce a
note or sound the pitch or tone of which will depend on the pressure of steam or
air maintained and on the velocity of the revolving ring.
The controlling cock or valve D is turned and fitted to be reciprocated in the
stationary casing as a seat A' by preference opening against the pressure of the
steam or compressed air, and this valve is opened or closed by a lever D¹ jointed
by a pin to snugs at d on the casing A, the extent of the opening being regulated
by a screw or similar device while the lever D' may be actuated at a distance by a
rod, wire, or cord attached to its outer end d².
The trumpet mouthpiece G shown in Figures 1 and 2 directs the sounds
produced upwards from the central outlet orifice F, but when it is desired to
project the sounds in any lateral direction, a kneed curved trumpet mouthpiece G¹,
as shown in sectional elevation in Figure 7, is fitted by the flange g over the
central opening F, instead of the straight trumpet G, to swivel on the fixed casing
by securing countersunk circular grooves for the bolts or other equivalent coupling
ring arrangement.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is
First. The general construction, or combination of parts, of sirens, or such sound
signalling apparatus, substantially as herein described in reference to and shown in
the accompanying drawings.
Second. The combination in a siren, or similar sound signalling apparatus, of an
outer stationary perforated cylinder and an inner rotating perforated cylinder or
annulus adapted thereto and operated by the steam or compressed air directed
from a space round the outer perforated stationary cylinder, substantially as herein
described in reference to and shown in the accompanying Drawings.
Third. The combination in a siren, or similar sound signalling apparatus, of the
stationary perforated cylinder B outside the rotating perforated cylinder or
annulus C, provided with vanes or buckets c¹ on the inner surface, and openings or
nozzles e adapted to direct steam or compressed air against such vanes or buckets,
to rotate the-cylinder, all substantially as and for the purposes herein described in
reference to and shown in the accompanying Drawings.

page_text: Fourth. In sirens, or similar sound signalling apparatus, the mounting of the
perforated revolving cylinder C, within the perforated stationary cylinder B, and
having the steain or compressed air directed from the outer circumference through
the perforations in these cylinders to the open space within the rotating cylinder,
substantially as and for the purposes herein described in reference to and shown in
the accompanying Drawings.