Improvements in Sirens, Sirenettes, and like Apparatus.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Sirens, Sirenettes, and like Apparatus.
We, WALTER MAY, of 63, Queen Victoria Street, in the City of London, Engineer,
and THE PULSOMETER ENGINEERING CO. LIMITED, of the Nine Elms Iron Works, in
the County of London, do hereby declare the nature of this invention to be as
follows:-
With the high steam pressures now common in steam ships, sirens, sirenettes
and like signalling apparatus as heretofore usually constructed are subject to
considerable friction, due partly to the direct pressure of such steam on the movable
portions of the apparatus and partly to expansion of portions of the apparatus, the.
result being that the sensitiveness and efficiency of the apparatus is liable to be
impaired. Now this invention has for object to obviate these disadvantages and
provide an efficient and reliable siren, sirenette or like apparatus (hereinafter
called a siren) that can be used with steam at various pressures.
For this purpose the revolving reed and the rotary brake device at the lower
end of the reed spindle, are arranged within a chamber or casing that is closed
at the bottom and formed at its upper part with number of angularly arranged
slots or openings through which and corresponding slots or openings in the reed,
high pressure steam admitted to the chamber of the siren intermittently passes to
the trumpet or outlet end of the siren, the arrangement being such that the brake
and adjacent parts are not subject to the action of high pressure steam.
For this purpose, in one arrangement the lower part of the chamber containing
the brake is screwed onto the upper portion containing the reed which consists of
a vertically slotted cylinder connected by arms to the spindle, the said upper
portion of the chamber being formed with a series of vertical slots and carried
by a flange by which it is secured to the flanged upper end of the steam chamber
to which steam is admitted past a valve that is opened against the action of a
spring by a lever. Between the upper and lower portions of the chamber or casing
is a diaphragm that serves as a bearing or guide for the reed spindle which passes
through it. In this arrangement only steam that has passed the reed and is con-
sequently at a low pressure can enter the portion of the chamber containing the
brake.
In order that the reed shall be quite free at starting so as to render the siren
very sensitive, the rotary brake is so mounted on the lower end of the reed spindle
that whilst it cannot turn independently of the spindle it is kept out of effective
action until the spindle has attained a predetermined rate of rotation. This may
be done in various ways.
According to one arrangement the brake comprises two hubs feathered to slide
on but turn with the reed spindle, a spiral spring surrounding the spindle and
acting to force the hubs apart, friction blocks adapted to revolve in contact with
the interior of the brake chamber, and pivoted arms or links arranged crosswise
to each other and connecting the hubs to the friction blocks, the arrangement
being such that when the brake is at rest and until a predetermined speed has
been reached, the said arms or links, or other means such as links attached to the

page_text: hubs by pin and slot connections, prevent the two hubs being forced apart and
into contact with the adjacent fixed parts of the siren by the spring. In this way
the brake is rendered free to slide endways on the spindle so that it will not interfere
with the free rotation of the reed at starting and any upward thrust on the spindle
is borne by the collar on the end of the upper bearing which is situated in low
pressure steam.
The lower end of the reed spindle may be rounded and supported upon a hard
metal ball within a hole in the bottom of the brake chamber. The upper end of
the said spindle may advantageously extend through a bearing that is formed at
the upper part of the trumpet and is packed with soft or white metal that is capable
of being compressed or set up, to compensate for wear, by a screw cap with internal
tubular extension fitting the spindle, or by a gland or like device.
As will be obvious some of our improvements may be used without the others.
1000
Арраго
We, WALTER MAY, of 63, Queen Victoria Street, in the City of London, Engineer,
and THE PULSOMETER ENGINEERING CO. LIMITED, of the Nine Elms Iron Works, in
the County of London, 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:-
With the high steam pressures now common on board steam ships, the sirens,
sirenettes and like signalling apparatus heretofore usually employed are subject
to considerable friction, due partly to the direct pressure and corresponding tem-
perature of such steam on the movable portions of the apparatus and partly to
expansion of portions of the apparatus, the result being that the sensitiveness
and efficiency of the apparatus are liable to be impaired. Now this invention has
for object to obviate these disadvantages and provide an efficient and reliable siren,
sirenette or like apparatus (hereinafter called a siren) than can advantageously be
used with steam at various pressures.
For this purpose the revolving reed and the rotary brake device at the lower
end of the reed spindle are arranged within a chamber or casing that is closed
at the bottom and formed at its upper part with a number of angularly arranged
slots or openings through which and through corresponding slots or openings in
the reed, high pressure steam admitted to the chamber of the siren intermittently
passes to the trumpet or outlet end of the siren, the arrangement being such that
the brake and adjacent parts are not subject to the action of high pressure steam.
Fig. of the accompanying illustrative drawings shows partly in vertical section
and partly in elevation, a siren constructed according to this invention. Fig. 2
is a section on the line A A of Fig. 1. Figs. 3 and 4 show respectively in vertical
and horizontal section and to a larger scale than Figs. 1 and 2 the closed brake
chamber with one construction of brake according to this invention. Figs. 5 6, 7
and 8 are detail views of parts of the brake mechanism.
1 is the revolving reed which comprises a vertical cylinder attached by a cone
shaped bottom 1 to the spindle 2 and mounted to rotate within a chamber or

page_text: casing 3 that is fixed concentrically within the steam chamber 4 by flanges 3"
and bolts and nuts 5. The upper portion of the chamber or casing 3 is provided
with a series of vertical slots 3b that are angularly arranged, and the vertical
cylindrical portion 1 of the reed is also provided with a similar series of angularly
arranged slots 1b (see Fig. 2). Between the upper and lower portions of the said
chamber or casing 3 is a diaphragm 3° which serves as a bearing or guide for
the reed spindle 2 which passes through it and to which is attached the brake
device hereinafter described. Steam enters the steam chamber 4 past a valve G
that is opened against the action of a spring 6 by a lever 7 pivoted at 7" to a
stationary part of the siren, the steam so admitted passing in an intermittent
manner through the slots 3b, 1b of the chamber or casing 3 and reed 1 respectively
into the trumpet 5. The construction and arrangement of the above described
parts is that commonly adopted in sirens.
According to this invention the lower portion of the chamber or casing 3 con-
taining the brake mounted on the lower portion of the spindle 2 is closed, as for
example by a cap 3* or equivalent closure, so as to form a closed brake chamber 3d
that prevents the high pressure steam from coming in contact with the brake and
producing undue friction.
In order that the reed 1 shall be quite free at starting and thereby render the
siren very sensitive, the rotary brake is so mounted on the lower end of the reed
spindle 2 that whilst it cannot turn independently of the spindle, it is kept out
of effective action until the spindle has attained a predetermined rate of rotation.
This may be done in various ways.
In the arrangement shown in Fig. 1 and to a larger scale in Figs. 3 to 8 inclusive,
the brake mechanism comprises two hubs 9 and 10 each formed with a hole to
freely fit the squared lower portion of the spindle 2 so that it can slide upon the
spindle but must turn with it; a coiled spring 11 that surrounds the spindle and
tends to force the hubs apart; two friction blocks 12 adapted to revolve in contact
with the interior of the brake chamber 3 but held out of contact therewith by the
spring until a predetermined speed is attained; and two pairs of pivoted arms or
links 13, 13 that connect the hubs 9 and 10 to the friction blocks 12 and are so
arranged that they prevent the two hubs being forced apart and into contact with
the adjacent fixed parts of the siren by the spring 11 whilst the brake is at rest.
For this latter purpose, each of the links 13 may be made of the bifurcated
shape shown in Figs. 5 and 6, the depth of each recess 13b therein being such
that when the brake is at rest the end 13 of the recess abuts against the outer side
of the corresponding link 13, the outer side of the link at the same time bearing
against inclined surfaces 12" on the corresponding brake block 12, thereby
locking the two hubs 9 and 10 against outward movement whilst permitting them
to be moved towards each other, against the action of the interposed spring 11 by
the centrifugal action of the brake blocks when the speed of the spindle rises
to a suitable extent. In this way the brake is at all times free to slide endways on
the spindle 2 and cannot interfere with the free rotation of the reed 1 at starting.
The lower end of the reed spindle 2 may be rounded and supported upon a hard
metal ball 16ª contained within a hole 16 formed on the inner side of the cap or
bottom 3* of the brake chamber 3d. By this construction the lower end of the
spindle is not subjected to the pressure of the steam as heretofore usual. The
upper end of the reed spindle is provided with a collar 14 whereby any upward
thrust on the spindle can be transmitted to the bottom of the upper bear-
ing 15 through which the spindle extends and which is situated in low pressure
steam. The bearing and spindle may advantageously be packed with soft or
white metal that is capable of being compressed or set up, to compensate for wear,
by a screw cap 17 provided with an internal tubular extension 17* fitting the spindle
or by a gland or like device. 18 is a hand wheel for turning the spindle 2 by
hand when necessary. 19 is a pulley around which a cord passes to enable the
trumpet 5 to be turned in any direction as well understood.
Figs. 9 and 10 are similar views to Figs. 1 and 4 showing a modified con-

page_text: struction of siren in which the brake enclosed within the chamber 3d is of
a different construction from that hereinbefore described and comprises a casting 20
fitted to slide on but to turn with the squared lower end of the spindle 2; vertical
pins 21 carried by the casting; and friction blocks 22 each mounted to turn on
one of the pins 21, shaped to fit the inner surface of the chamber 3d, and provided
with an extension 23 to limit its inward movement. The trumpet in this arrange-
ment is made shorter than that shown in Fig. 1, and instead of being fitted to turn
relatively to the steam chamber 4 and chamber or casing 3 is fixed to the steam
chamber which is mounted to revolve and carry the trumpet with it. Also the
flanged upper end of the chamber or casing 3 instead of being fixed to the upper
flanged end of the steam chamber is recessed into such end and secured to the
lower flanged end of the trumpet so as to lift with the trumpet when this is removed
from the steam chamber. In other respects the construction is similar to that
shown in Figs. 1 and 2.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. A siren of the kind herein referred to wherein the chamber or casing con-
taining the brake device is closed at the bottom so that the, said brake device and
adjacent parts will not be subject to the action of high pressure steam, substantially
as described for the purpose specified.
2. A siren wherein the rotary brake for controlling the motion of the reed is
so mounted on the reed spindle that whilst it cannot turn independently of that
spindle it will be kept out of effective action until the spindle has attained a pre-
determined rate of rotation, substantially as described for the purpose specified.
3. In a siren, the improved rotary brake constructed, arranged and operating,
substantially as described and shown.
4. A siren of the kind herein referred to wherein the upper end of the reed
spindle is supported by an upper bearing constructed and arranged substantially
as described and shown, and upward thrust on the spindle is taken by the inner
end of such bearing as set forth.
5. The improved sirens constructed and arranged as herein before described with
reference to and shown in the drawings annexed.
the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.