In- PROVEMENTS IN Foe SIGNALS, WHICH ARE ALSO APPLICABLE TO OTHER SIGNALLING PURPOSES
Year: 1875

page_text: LETTERS PATENT to Frederick Hale Holmes, of West Brompton, in
the County of Middlesex, Engineer, for the Invention of "In-
PROVEMENTS IN Foe SIGNALS, WHICH ARE ALSO APPLICABLE TO OTHER
SIGNALLING PURPOSES."
PROVISIONAL SPECIFICATION left by the said Frederick Hale Holmes
at the Office of the Commissioners of Patents, with his Petition,
on the 2nd October 1875.
I, FREDERICK HALE HOLMES, of West Brompton, in the County of
Middlesex, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN FOG SIGNALS, WHICH ARE ALSO APPLICABLE TO OTHER
SIGNALLING PURPOSES," to be as follows:-
My Invention relates to fog signals suitable for lighthouses, light
vessels, and for making signals at sea, but which are also otherwise
applicable for signalling by sound.
One part of my Invention relates to the automatic apparatus
described in the Specification of Letters Patent granted to me 14th

page_text: March 1871, No. 674, and has reference to the manner of opening and
closing the valve which allows the compressed air or steam to sound
either the ordinary fog horn or siren, and it consists,―
1st. In fixing on the end of the valve spindle a piston of larger
diameter than the valve, and covered by a diaphragm of vulcanized
india-rubber in the case where compressed air is employed, or a
diaphragm of corrugated metal where steam is used for sounding, or I
make this piston a steam tight fit by means of thin metallic rings. The
piston with its diaphragm is enclosed by a cover in a ring or cylinder, so
as to be capable of travelling through a small space in such ring or
cylinder of and between the cover of the ring or cylinder and the
diaphragm; a small space is also left when the valve is closed.
Secondly. In the introduction into the automatic apparatus of a small
double valve, one valve being an inlet, and the other an outlet valve, so
constructed and arranged that when the valve spindle is pressed down 1
the inlet valve is opened, allowing the compressed air to enter the valve
box, and the other valve descends on to the top of the valve box, thus
cutting off communication with the external atmosphero. This valve
box is connected by a small pipe with the space above the diaphragm
herein-before described, and below or outside of the inlet valve another :
small pipe is provided when required, such pipe leading from the com-
pressed air vessel, or the valve box is fixed direct to the compressed air
vessel. The object of these two valves in combination is to obtain a
sudden opening and closing of the sounding valve to its full distance, so
as to give the horn or siren the whole or full pressure instantly, and to
close it as quickly with a minimum of force.
The valves herein-before described operate in the following manner,
viz. When the pressure arrives in the air cylinder or vessel at that at
which the automatic apparatus is adjusted, the ball described in my
former Specification falls over and carries with it a small cam wheel,
bringing the cam on to the top of the outlet valve, whereby this valve is
closed and the interior of the valve box shut off from the atmosphere,
and at the same time the lower or inlet valve is opened. The com-
pressed air now passes from the compressed air cylinder to the space
above the diaphragm of the piston herein-before described and presses on
such piston, and as this piston is larger than the sound valve, this valve

page_text: small valve, but as soon as the pressure in the compressed air cylinder is
reduced by the escape of air to a degree corresponding with the arrange-
ment of the automatic apparatus, the ball herein-before referred to will
fall in the opposite direction, and the cam will be removed from the
outer or atmospheric valve. The inlet valve will then close by the
pressure assisted by a spring and the outer or atmospheric valve will
open, thus allowing a free passage for the compressed air above the
diaphragm to pass into the atmosphere, when by the pressure of the
compressed air on the sound valve, assisted by a spring, this valve will
instantly close.
Another part of my Invention relates to the siren when used either as
an ordinary fog signal for lighthouses or lightships, or for making
signals on board ship, and has for its object making a siren that shall
turn by the action of the air passing through it, produce at the same
time a given musical note or combination of notes, which note or notes
shall not vary at varying pressures of air. In order to effect this object
I make a suitable number of round holes or slots in the fixed and
revolving discs in a slanting direction (others being cut or bored per-
pendicularly to the axis), but in the fixed disc the slant is in one
direction, and in the revolving disc in the other direction. The siren
thus cut would (at a constant pressure) continually accellerate its speed
and change its note, or as the pressure diminishes the velocity would
diminish also, and the note or notes would change.
According to my Invention, in order to prevent this changement of
note or notes with changement of pressure, I fix on the spindle of the
revolving disc a set of fans which revolve with it enclosed in air at the
same pressure as that which causes the disc to revolve, and thus as
the force to turn the disc varies so will the resistance of the fans vary,
and the speed once adjusted for any note or notes will always remain the
same for all pressures. A small spring catch or pawl fixed on the
spindle of the sound valve when the valve is in the act of being opened
engages in a toothed or ratchet wheel fixed on the spindle of the
revolving disc so as to start it should it have stopped in such a position
that the slanting holes in the fixed disc are opposite blank spaces in the
revolving disc. The fans may be so arranged as when at rest to be in a

page_text: position nearly at right angles to their axis, but to change their position
to offer their maximum resistance as soon as the proper velocity is
acquired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Hale Holmes in the Great Seal Patent
Office on the 30th March 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
HALE HOLMES, of West Brompton, in the County of Middlesex,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of October, in the year
of our Lord One thousand eight hundred and seventy-five, in the
39th year of Her reign, did, for Herself, Her heirs, and suc-
cessors, give and grant unto me, the said Frederick Hale Holmes,
Her special license that I, the said Frederick Hale Holmes, my
executors, administrators, and assigns, or such others as I, the said
Frederick Hale Holmes, my executors, administrators, or assigns,
should at any 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 "IMPROVEMENTS IN FOG SIGNALS, WHICH
ARE ALSO APPLICABLE TO OTHER SIGNALLING PURPOSES," upon the condition
(amongst others) that I, the said Frederick Hale Holmes, my executors
or administrators, by an instrument in writing under my hand and 2
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 Frederick Hale Holmes, do hereby
declare the nature of my said Invention, and in what manner the
be particularly described and ascer-
tained in and by the following statement, reference being had to the
same is to be performed, to

page_text: accompanying Drawings and to the letters and ugures marked thereon,
that is to say:-
-
My said Invention relates to fog signals suitable for lighthouses,
lightships, and for making signals at sea, but which are also otherwise
applicable for signalling by sound, and it consists,―
First. Of improvements on the automatic apparatus for similar
purposes described in the Specification of Letters Patent granted to me
the Fourteenth March, One thousand eight hundred and seventy-one,
No. 674. This part of my Invention has reference to the manner of
opening and closing the valve which allows the compressed air or steam
to sound either the ordinary fog horn or a siren.
Secondly. Of improvements upon the siren when used either as an
ordinary fog signal for lighthouses or lightships, or for making signals
on board ship or on shore, or both. This part of my Invention has for
its object constructing a siren which shall revolve by the action of the
compressed air or steam in passing through it, and produce at the same
time a given musical note or combination of notes, which note or notes
shall not vary at varying pressures of air or steam.
And in order that my said Invention may be fully understood I shall
now proceed more particularly to describo the same, and for that purpose
shall refer to the several Figures on the annexed Sheets of Drawings,
the same letters of reference indicating corresponding parts in all the
corresponding Figures.
The first part of my Invention is illustrated on Sheet 1, and the
second part is illustrated on Sheets 1 and 2 of the Drawings hereunto
annexed.
Referring to Sheet 1 of my Drawings on which the first part of my
Invention is shown as applied to a siren for a lighthouse or lightship,
Figures 1 and 2 represent the general arrangement of the apparatus in
elevation and plan respectively; Figure 3 is a longitudinal section
taken through the valve box and siren box; Figure 4 is an enlarged
detail; and Figures 5 and 6 represent modifications to be herein-after
referred to.
A, Figures 1 and 2, represents a lever, which when lifted by the
piston B, as described in the Specification to my said former Letters
Patent, turns the wheel C and brings a cam wheel D on to the top of

page_text: a small double valve E, shewn in section (full size) in Figure 4, and at
the same time throws over the ball F to the dotted position shewn in
Figure 1. In this double valve G is the outlet valve and H is the
inlet valve, the details of which may be varied, but the arrangement
shewn has been found suitable in practice. As long as the cam D
presses on the top of the valve the outlet valve G, Figures 1 and 4,
remains closed and the inlet valve H, Figure 4, remains open, and the
compressed air, for example, passes from the air cylinder J through the
passage 1 (Figure 4), and thence by the pipe K, Figures 1 and 2, to
the space 2 above the piston L (shown in section in Figure 3). This
piston is provided with a diaphragm I composed of vulcanized india-
rubber; or if steam is employed the diaphragm is by preference
composed of corrugated metal; or the diaphragm may be dispensed with
by packing the piston L steam-tight. The piston L I make larger than
the valve M, Figure 3, which closes the lower part of the valve box N';
the pressure above the piston consequently forces the valve M to open
instantly, and the compressed air passes through the connecting tube L'
to the siren box N, and will continue to pass until the pressure in the
air cylinder is reduced, so that the weight O, Figures 1 and 2, falls,
when at the same time the ball F returns to its former position, which
is that indicated by full lines in my Drawing. The cam D is thus
removed from the top of the valve G, and by the pressure of the com-
pressed air assisted by a spring P, Figure 4, the inlet valve II closes and
the outlet valve G opens, allowing the compressed air above the piston
to pass freely through the passages 3, Figure 4, into the atmosphere,
when the valve M. closes instantly by the pressure on M, assisted by the
spring Q, Figure 3. The valves will now remain closed until the
pressure arrives at the same degree as before, when the lever A will be
again lifted and the sound repeated, and by adjusting the size of
the weight O and the size of the ball F to the pressure a regular
proportion between the duration of sound and silence can be established.
The apparatus herein-before described is arranged for the production
of one prolonged sound at certain intervals, but for the purpose of
distinguishing one fog signal station from another it is found necessary
to divide this sound, say of five seconds duration into two of or three
of seconds duration. The principle of employing the small compound
valve E, Figure 4, to open the large valvo M, Figure 3, enables this
result to be accomplished with facility, as a force of about 1/1000 only

page_text: of that which is required for opening the large valve is sumcient to
effect the opening of the small valve. It is simply necessary in order
to produce the repeating seconds to replace the can wheel D and the
toothed wheel O by an arrangement similar to that shewn in Figures 5
and 6, which Figures represent in side and end elevations respectively
apparatus adapted for sounding three short sounds at intervals, in lieu of
one continued sound.
R is a cam wheel provided on its periphery with twenty-four cams or
tappets S, S, with the spaces between the cams about double the length
of the cams, and also having fixed to its side eight arms T projecting
beyond the cams, as shewn clearly in Figure 5. This cam wheel is fast
on the axis or shaft U. V is a wheel fitted loosely on the shaft U,
which wheel has teeth cut in a portion of its edge, and carries a pawl W ;
X is a ratchet wheel secured to a drum Y, Figure 6, enclosing a spring
similar to an ordinary eight-day clock spring, the inner end of which
spring is fixed to the shaft U, whilst its outer end is attached to the
drum Y. The end of the lever A, Figures 1, 2, and 5, takes into the
teeth in V, Figure 5; a detent Z, Figures 5 and 6, fixed to the standard (a)
is provided in order to prevent any return motion of the ratchet
wheel X when the latter is operated as herein-after described.
On a
standard a¹ in a line with and underneath the lever A. there is mounted
a bolt 6, Figure 5, which is provided with a projection c, and also with
two other projections, videlicet, one d secured to the standard a¹ and
passing through a slot in the bolt 6; the other e fixed to the bolt.
The projections & and e are connected by a spiral spring 4, which tends
to retain the bolt in the position shewn in Figure 5. The shaft U
has also secured thereon a worm wheel f, Figures 5 and 6, with which
engages a worm g mounted on a vertical shaft h, Figure 6, carrying
regulating fans j.
The apparatus operates in the following manner, videlicet:-The
spring contained in the drum Y is wound up by turning the cam
wheel R (when the apparatus is first put together) until the cam wheel
acquires a force more than sufficient to press down the valve E when
under the full pressure at which it will be required to act. When
however the apparatus has been once adjusted no further winding up by
hand is necessary, as will be seen by the following description of the
action of the apparatus:-When the lever A is raised by the pressure
the end & descends, and the teeth turn the wheel V through of a

page_text: revolution. The pawl W by engaging in the teeth of the ratchet
wheel X winds up the spring of a revolution, which is precisely tho
amount by which it will run down when the cam wheel arms T have
passed from T to T, Figure 5. The edge 2, Figure 5, by the descent of
the end of the lever A forces back the bolt 6 by pressing on the
projection c, and liberates the projecting arm T which rested on the
bolt. The cam wheel now turns by the force of the spring with a speed
regulated by the fans j, Figure 6, but as soon as the siren or horn has
sounded once the lever A falls owing to the diminished pressure, and tho
end k rises, turning back at the same time the wheel V into its original
position, the detent Z however on the standard a preventing the spring
from following it, and thus unwinding itself. At the same time that
the end rises it liberates the bolt b, which under the action of tho
spring 4, between d and e, is forced again into its position, as shewn in
the Drawing, ready to stop the arm T³ when it arrives, by which time
three cams will have acted on the small valve E, Figure 1, and the horn
or siren will have sounded three times at short intervals, and the spring
will have exactly the same force as that first imparted to it. The length
of the three sounds can be regulated to the greatest precision by varying
the angles of the fans j. After once operating the apparatus will not
sound again until the pressure in the air cylinder J is again sufficient to
lift the lever A, as explained in my said former Specification.
In carrying out the second part of my Invention I construct sirens as
shewn in Figures 1, 2, 3, Sheet 1, and Figures 7, 8, 9, and 12, Sheet 2
of the Drawings, for lighthouses, and as shewn in Figures 10, 11, 12,
and 13 (Sheet 2) for signalling purposes, but in the latter case sirens
may also be employed of the form shewn in Figure 9; and in order to
explain this part of my Invention I will first point out on the Drawings
the different parts and their construction, and then explain their
action.
A', Figures 3, 7, 8, 9, 10, and 11 shew the forms of sirens that I
employ, and Figure 9 shews a form of siren producing two notes, which
accord in all the Figures. a' represents the fixed part, and b' the
moveable part; N, Figures 1, 2, 3, 7, 10, 11, and 13, represent the siren
box; Figures 3, 7, 10, and 11 are sections showing how the siren is a
arranged in the box.
B', Figures 3, 7, 10, and 11, are the fans for regulating the velocity of
the siren by revolving in the compressed air or steam;

page_text: C', Figures 3, 7, 10, and 11, is the shaft or spindle of the moveable
disc of the siren.
D', Figures 3, 7, 10, and 11, is a ratchet wheel, cast or otherwise,
fixed on the spindle or shaft C'.
E', Figures 8, 7, 10, and 11, is a pawl in Figures 10 and 11 shewn
fixed on the valve spindle, and in Figures 8 and 7 on the rod c³, which
passes through the two guide pieces e and e², and is provided on its
end a flat diso f¹, behind which is a spring g¹ to maintain it in position
when not pressed forward by the compressed air passing through L'.
F, Figures 8, 7, 10, and 11, are friction weights for the adjustment
of the note or notes by their friction against the inner surface of N, as
soon as the centrifugal force overcomes the force of the springs dª.
Figures 8, 9, and 12 shew the slant or angle of the sides of the
apertures in either the flat discs, Figures 8 and 9, or those with
3 cylindrical peripheries, Figure 12.
G³, Figures 11 and 13, is a lever by which the valve is opened and
the siren started by the pawl at the same instant.
H', Figures 11 and 13, is a balance weight on the back end of the
lever G³ to assist in closing the valve K².
J', Figures 1, 2, 3, 7, 10, and 13, are the horns of the sirens; Figures
1, 2, 8, and 7, for lighthouses; and Figures 10 and 13 for signalling
apparatus for ships. In Figure 3 only a portion of the horn is shewn
in section, for the purpose of indicating the ball and socket joint
employed in order to enable the mouth of the horn to be turned to face
the wind. In Figure 7 a portion only of two horns is shown; the
mouths of these horns can be set parallel or making any required angle
one with the other, and in this double horn apparatus the two horns
can either be in perfect unison or they may be arranged so that each
sounds a different note but in perfect accord one with the other, by
placing one horn over the outer circle and the other over the inner circle
of apertures in Figure 9.
K', Figure 10, is the valve of the signalling apparatus by which the
steam or compressed air is admitted to the siren box N. The valve is
placed immediately above a stuffing box (not shown in my Drawings)
so as to enable the horn to be turned towards the vessel or point to

page_text: the automatic apparatus.
L', Figures 1, 2, 3, and 7, is a connecting tube between the valve box
and the siren box in the lighthouse apparatus.
N', Figures 1, 2, 3, and 7, is the large valve box of the automatic
apparatus; Figure 3 is a section through the centre of N', N (Figure 1).
I shall now proceed to explain the manner of using the sirens, and
will commence with the signalling sirens, Figures 10, 11, and 13
(Sheet 2). When the lever G¹ is pressed or drawn down it performs two
functions, videlicet, it opens the valve and starts the siren; this starting
of the siren is important, for if the shutters in the moveable disc were
exactly over the apertures in the fixed disc when the steam is admitted
the siren would not move, and consequently no sound would be
produced. The steam being admitted and the siren started, the steam
in passing through the apertures produces in consequence of the form
of the apertures (Figures 8, 9, and 12) a rotative movement, which
would continually accelerate were it not controlled, but the weights F¹
fly out as soon as the velocity has arrived at the point at which the
centrifugal force overcomes the force of the springs d', and the friction
against the inside of N reacts against the rotative force. If, however,
the pressure changes the velocity will change; in order therefore to
prevent this result the fans B' are introduced, which act with the
friction weights as a resistance to the velocity, but vary in their
resistance exactly as the pressure of steam varies, producing as a result
a constant steady note or an accord if a siren of the form shewn in
Figure 9 is used. The weights F constitute what may be termed the
adjustment of the note, and the fans form the means of maintaining it
steady. In the signalling apparatus, when steam is employed the
weights are of the more consequence, but with compressed air which
is constantly diminishing in pressure as it escapes the fans are the
more important.
The above explanation of the action of the siren apparatus for
signalling will serve generally for the lighthouse fog signals, with the
exception that as the latter are entirely automatic no lever is employed
to start the siren, the rod a' being mado to perform this duty. When
the large valve M, Figure 3, is opened suddenly by the small valve E,
the compressed air passes through L' and presses with considerable force

page_text: of fans for regulating its speed, substantially as and for the purposes
herein-before described.
In witness whereof, I, the said Frederick Hale Holmes, have to
this my Specification set my hand and seal, the Twenty-second
day of March, One thousand eight hundred and seventy-six.